[tint][msl] Fix C++17 warning. Bug: tint:2125 Bug: chromium:1521309 Change-Id: Id8189ffb5a77fbce409cb0b0ee14656b0da55f6c Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/171240 Kokoro: Ben Clayton <bclayton@google.com> Commit-Queue: Ben Clayton <bclayton@google.com> Kokoro: Kokoro <noreply+kokoro@google.com> Reviewed-by: David Neto <dneto@google.com> Auto-Submit: Ben Clayton <bclayton@google.com> (cherry picked from commit 02262d895ff373badfc4d2233f8e14108d185687) Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/171440 Reviewed-by: Corentin Wallez <cwallez@chromium.org>

diff --git a/src/tint/lang/msl/writer/ast_printer/ast_printer.cc b/src/tint/lang/msl/writer/ast_printer/ast_printer.cc
index 718770e..81caedb 100644
--- a/src/tint/lang/msl/writer/ast_printer/ast_printer.cc
+++ b/src/tint/lang/msl/writer/ast_printer/ast_printer.cc

@@ -3018,16 +3018,17 @@
     return true;
 }
 
-std::string_view ASTPrinter::IsolateUB() {
+std::string ASTPrinter::IsolateUB() {
     if (isolate_ub_macro_name_.empty()) {
         isolate_ub_macro_name_ = UniqueIdentifier("TINT_ISOLATE_UB");
-        auto volatile_true = UniqueIdentifier("tint_volatile_true");
-        Line(&helpers_) << "#define " << isolate_ub_macro_name_ << " \\";
-        Line(&helpers_) << "  if (volatile bool " << volatile_true << " = true; " << volatile_true
-                        << ")";
+        Line(&helpers_) << "#define " << isolate_ub_macro_name_ << "(VOLATILE_NAME) \\";
+        Line(&helpers_) << "  volatile bool VOLATILE_NAME = true; \\";
+        Line(&helpers_) << "  if (VOLATILE_NAME)";
         Line(&helpers_);
     }
-    return isolate_ub_macro_name_;
+    StringStream ss;
+    ss << isolate_ub_macro_name_ << "(" << UniqueIdentifier("tint_volatile_true") << ")";
+    return ss.str();
 }
 
 template <typename F>

diff --git a/src/tint/lang/msl/writer/ast_printer/ast_printer.h b/src/tint/lang/msl/writer/ast_printer/ast_printer.h
index 70269c9..a9e9378 100644
--- a/src/tint/lang/msl/writer/ast_printer/ast_printer.h
+++ b/src/tint/lang/msl/writer/ast_printer/ast_printer.h

@@ -380,8 +380,8 @@
 
     /// Lazilly generates the TINT_ISOLATE_UB macro, used to prevent UB statements from affecting
     /// later logic.
-    /// @return the unique name of the TINT_ISOLATE_UB macro.
-    std::string_view IsolateUB();
+    /// @return the MSL to call the TINT_ISOLATE_UB macro.
+    std::string IsolateUB();
 
     /// Handles generating a builtin name
     /// @param builtin the semantic info for the builtin

diff --git a/src/tint/lang/msl/writer/ast_printer/ast_printer_test.cc b/src/tint/lang/msl/writer/ast_printer/ast_printer_test.cc
index 74d8fdd..28a2d3e 100644
--- a/src/tint/lang/msl/writer/ast_printer/ast_printer_test.cc
+++ b/src/tint/lang/msl/writer/ast_printer/ast_printer_test.cc

@@ -226,15 +226,16 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_3 {
   tint_array<float2x2, 4> m;
 };
 
 void comp_main_inner(uint local_invocation_index, threadgroup tint_array<float2x2, 4>* const tint_symbol) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = float2x2(float2(0.0f), float2(0.0f));
   }

diff --git a/src/tint/lang/msl/writer/ast_printer/continue_test.cc b/src/tint/lang/msl/writer/ast_printer/continue_test.cc
index 727f05c..ad68153 100644
--- a/src/tint/lang/msl/writer/ast_printer/continue_test.cc
+++ b/src/tint/lang/msl/writer/ast_printer/continue_test.cc

@@ -44,11 +44,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void test_function() {
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if (false) {
       break;
     }

diff --git a/src/tint/lang/msl/writer/ast_printer/loop_test.cc b/src/tint/lang/msl/writer/ast_printer/loop_test.cc
index 7aed227..3d1dd64 100644
--- a/src/tint/lang/msl/writer/ast_printer/loop_test.cc
+++ b/src/tint/lang/msl/writer/ast_printer/loop_test.cc

@@ -51,11 +51,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 fragment void F() {
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     break;
   }
   return;
@@ -80,14 +81,15 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void a_statement() {
 }
 
 fragment void F() {
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     break;
     {
       a_statement();
@@ -115,14 +117,15 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void a_statement() {
 }
 
 fragment void F() {
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     break;
     {
       a_statement();
@@ -156,8 +159,8 @@
     ASTPrinter& gen = Build();
 
     ASSERT_TRUE(gen.EmitStatement(outer)) << gen.Diagnostics();
-    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB while(true) {
-  TINT_ISOLATE_UB while(true) {
+    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB(tint_volatile_true) while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) while(true) {
     break;
     {
       a_statement();
@@ -194,7 +197,7 @@
     ASTPrinter& gen = Build();
 
     ASSERT_TRUE(gen.EmitStatement(outer)) << gen.Diagnostics();
-    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB while(true) {
+    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB(tint_volatile_true) while(true) {
   float lhs = 2.5f;
   float other = 0.0f;
   break;
@@ -217,7 +220,7 @@
     ASTPrinter& gen = Build();
 
     ASSERT_TRUE(gen.EmitStatement(f)) << gen.Diagnostics();
-    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB for(; ; ) {
+    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB(tint_volatile_true) for(; ; ) {
   return;
 }
 )");
@@ -235,7 +238,7 @@
     ASTPrinter& gen = Build();
 
     ASSERT_TRUE(gen.EmitStatement(f)) << gen.Diagnostics();
-    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB for(int i = 0; ; ) {
+    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; ; ) {
   return;
 }
 )");
@@ -266,7 +269,7 @@
     f(1);
     f(2);
   }
-  TINT_ISOLATE_UB for(; ; ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; ; ) {
     return;
   }
 }
@@ -285,7 +288,7 @@
     ASTPrinter& gen = Build();
 
     ASSERT_TRUE(gen.EmitStatement(f)) << gen.Diagnostics();
-    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB for(; true; ) {
+    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB(tint_volatile_true) for(; true; ) {
   return;
 }
 )");
@@ -304,8 +307,9 @@
     ASTPrinter& gen = Build();
 
     ASSERT_TRUE(gen.EmitStatement(f)) << gen.Diagnostics();
-    EXPECT_EQ(gen.Result(),
-              R"(TINT_ISOLATE_UB for(; ; i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+    EXPECT_EQ(
+        gen.Result(),
+        R"(TINT_ISOLATE_UB(tint_volatile_true) for(; ; i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
   return;
 }
 )");
@@ -331,7 +335,7 @@
     ASTPrinter& gen = Build();
 
     ASSERT_TRUE(gen.EmitStatement(loop)) << gen.Diagnostics();
-    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB while(true) {
+    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB(tint_volatile_true) while(true) {
   return;
   {
     f(1);
@@ -357,7 +361,7 @@
     ASSERT_TRUE(gen.EmitStatement(f)) << gen.Diagnostics();
     EXPECT_EQ(
         gen.Result(),
-        R"(TINT_ISOLATE_UB for(int i = 0; true; i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+        R"(TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; true; i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
   a_statement();
 }
 )");
@@ -389,7 +393,7 @@
     f(1);
     f(2);
   }
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if (!(true)) { break; }
     return;
     {
@@ -412,7 +416,7 @@
     ASTPrinter& gen = Build();
 
     ASSERT_TRUE(gen.EmitStatement(f)) << gen.Diagnostics();
-    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB while(true) {
+    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB(tint_volatile_true) while(true) {
   return;
 }
 )");
@@ -429,7 +433,7 @@
     ASTPrinter& gen = Build();
 
     ASSERT_TRUE(gen.EmitStatement(f)) << gen.Diagnostics();
-    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB while(true) {
+    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB(tint_volatile_true) while(true) {
   continue;
 }
 )");
@@ -449,7 +453,7 @@
     ASTPrinter& gen = Build();
 
     ASSERT_TRUE(gen.EmitStatement(f)) << gen.Diagnostics();
-    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB while((t && false)) {
+    EXPECT_EQ(gen.Result(), R"(TINT_ISOLATE_UB(tint_volatile_true) while((t && false)) {
   return;
 }
 )");

diff --git a/test/tint/array/assign_to_function_var.wgsl.expected.msl b/test/tint/array/assign_to_function_var.wgsl.expected.msl
index 2c9731b..8de70f5 100644
--- a/test/tint/array/assign_to_function_var.wgsl.expected.msl
+++ b/test/tint/array/assign_to_function_var.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   tint_array<int4, 4> src_private;
@@ -57,7 +58,7 @@
 }
 
 void tint_symbol_inner(uint local_invocation_index, thread tint_private_vars_struct* const tint_private_vars, threadgroup tint_array<int4, 4>* const tint_symbol_8, const constant S* const tint_symbol_9, device S* const tint_symbol_10) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol_8))[i] = int4(0);
   }

diff --git a/test/tint/array/assign_to_private_var.wgsl.expected.msl b/test/tint/array/assign_to_private_var.wgsl.expected.msl
index 5e2e692..5fe77e8 100644
--- a/test/tint/array/assign_to_private_var.wgsl.expected.msl
+++ b/test/tint/array/assign_to_private_var.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   tint_array<int4, 4> src_private;
@@ -57,7 +58,7 @@
 }
 
 void tint_symbol_inner(uint local_invocation_index, thread tint_private_vars_struct* const tint_private_vars, threadgroup tint_array<int4, 4>* const tint_symbol_8, const constant S* const tint_symbol_9, device S* const tint_symbol_10) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol_8))[i] = int4(0);
   }

diff --git a/test/tint/array/assign_to_storage_var.wgsl.expected.msl b/test/tint/array/assign_to_storage_var.wgsl.expected.msl
index e0a8b7d..bdfe75a 100644
--- a/test/tint/array/assign_to_storage_var.wgsl.expected.msl
+++ b/test/tint/array/assign_to_storage_var.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   tint_array<int4, 4> src_private;
@@ -59,7 +60,7 @@
 }
 
 void tint_symbol_inner(uint local_invocation_index, thread tint_private_vars_struct* const tint_private_vars, threadgroup tint_array<int4, 4>* const tint_symbol_10, device S* const tint_symbol_11, const constant S* const tint_symbol_12, device S* const tint_symbol_13, device S_nested* const tint_symbol_14) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol_10))[i] = int4(0);
   }

diff --git a/test/tint/array/assign_to_workgroup_var.wgsl.expected.msl b/test/tint/array/assign_to_workgroup_var.wgsl.expected.msl
index bc6e5d4..e45a4b0 100644
--- a/test/tint/array/assign_to_workgroup_var.wgsl.expected.msl
+++ b/test/tint/array/assign_to_workgroup_var.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   tint_array<int4, 4> src_private;
@@ -55,12 +56,12 @@
 }
 
 void tint_symbol_inner(uint local_invocation_index, thread tint_private_vars_struct* const tint_private_vars, threadgroup tint_array<int4, 4>* const tint_symbol_10, threadgroup tint_array<int4, 4>* const tint_symbol_11, threadgroup tint_array<tint_array<tint_array<int, 2>, 3>, 4>* const tint_symbol_12, const constant S* const tint_symbol_13, device S* const tint_symbol_14) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol_10))[i] = int4(0);
     (*(tint_symbol_11))[i] = int4(0);
   }
-  TINT_ISOLATE_UB for(uint idx_1 = local_invocation_index; (idx_1 < 24u); idx_1 = (idx_1 + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(uint idx_1 = local_invocation_index; (idx_1 < 24u); idx_1 = (idx_1 + 1u)) {
     uint const i_1 = (idx_1 / 6u);
     uint const i_2 = ((idx_1 % 6u) / 2u);
     uint const i_3 = (idx_1 % 2u);

diff --git a/test/tint/array/strides.spvasm.expected.msl b/test/tint/array/strides.spvasm.expected.msl
index 3499687..331afc2 100644
--- a/test/tint/array/strides.spvasm.expected.msl
+++ b/test/tint/array/strides.spvasm.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct strided_arr {
   /* 0x0000 */ float el;
@@ -36,13 +37,13 @@
 }
 
 void assign_and_preserve_padding_3(device tint_array<strided_arr, 2>* const dest, tint_array<strided_arr, 2> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 2u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 2u); i = (i + 1u)) {
     assign_and_preserve_padding_4(&((*(dest))[i]), value[i]);
   }
 }
 
 void assign_and_preserve_padding_2(device tint_array<tint_array<strided_arr, 2>, 3>* const dest, tint_array<tint_array<strided_arr, 2>, 3> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 3u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(uint i = 0u; (i < 3u); i = (i + 1u)) {
     assign_and_preserve_padding_3(&((*(dest))[i]), value[i]);
   }
 }
@@ -52,7 +53,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<strided_arr_1, 4>* const dest, tint_array<strided_arr_1, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_2) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/storage/dynamic_index/write.wgsl.expected.msl b/test/tint/buffer/storage/dynamic_index/write.wgsl.expected.msl
index d4470df..beaa591 100644
--- a/test/tint/buffer/storage/dynamic_index/write.wgsl.expected.msl
+++ b/test/tint/buffer/storage/dynamic_index/write.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f32_array_element {
   /* 0x0000 */ packed_float3 elements;
@@ -105,7 +106,7 @@
 }
 
 void assign_and_preserve_padding_3(device tint_array<tint_packed_vec3_f32_array_element, 2>* const dest, tint_array<float3, 2> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 2u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 2u); i = (i + 1u)) {
     (*(dest))[i].elements = packed_float3(value[i]);
   }
 }

diff --git a/test/tint/buffer/storage/dynamic_index/write_f16.wgsl.expected.msl b/test/tint/buffer/storage/dynamic_index/write_f16.wgsl.expected.msl
index ee7f114..ba02219 100644
--- a/test/tint/buffer/storage/dynamic_index/write_f16.wgsl.expected.msl
+++ b/test/tint/buffer/storage/dynamic_index/write_f16.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f32_array_element {
   /* 0x0000 */ packed_float3 elements;
@@ -160,7 +161,7 @@
 }
 
 void assign_and_preserve_padding_6(device tint_array<tint_packed_vec3_f32_array_element, 2>* const dest, tint_array<float3, 2> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 2u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 2u); i = (i + 1u)) {
     (*(dest))[i].elements = packed_float3(value[i]);
   }
 }

diff --git a/test/tint/buffer/storage/static_index/write.wgsl.expected.msl b/test/tint/buffer/storage/static_index/write.wgsl.expected.msl
index 7d6a510..69afba3 100644
--- a/test/tint/buffer/storage/static_index/write.wgsl.expected.msl
+++ b/test/tint/buffer/storage/static_index/write.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f32_array_element {
   /* 0x0000 */ packed_float3 elements;
@@ -107,7 +108,7 @@
 }
 
 void assign_and_preserve_padding_3(device tint_array<tint_packed_vec3_f32_array_element, 2>* const dest, tint_array<float3, 2> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 2u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 2u); i = (i + 1u)) {
     (*(dest))[i].elements = packed_float3(value[i]);
   }
 }

diff --git a/test/tint/buffer/storage/static_index/write_f16.wgsl.expected.msl b/test/tint/buffer/storage/static_index/write_f16.wgsl.expected.msl
index f28bf39..ef66275 100644
--- a/test/tint/buffer/storage/static_index/write_f16.wgsl.expected.msl
+++ b/test/tint/buffer/storage/static_index/write_f16.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f32_array_element {
   /* 0x0000 */ packed_float3 elements;
@@ -164,7 +165,7 @@
 }
 
 void assign_and_preserve_padding_6(device tint_array<tint_packed_vec3_f32_array_element, 2>* const dest, tint_array<float3, 2> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 2u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 2u); i = (i + 1u)) {
     (*(dest))[i].elements = packed_float3(value[i]);
   }
 }
@@ -176,7 +177,7 @@
 }
 
 void assign_and_preserve_padding_8(device tint_array<Inner, 4>* const dest, tint_array<Inner, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_7(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/array/mat2x2_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat2x2_f32/to_workgroup.wgsl.expected.msl
index d9ef1ab..8c973bd 100644
--- a/test/tint/buffer/uniform/std140/array/mat2x2_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat2x2_f32/to_workgroup.wgsl.expected.msl

@@ -14,15 +14,16 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<float2x2, 4> w;
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<float2x2, 4>* const tint_symbol, const constant tint_array<float2x2, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = float2x2(float2(0.0f), float2(0.0f));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat2x3_f16/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat2x3_f16/to_storage.wgsl.expected.msl
index e09bee8..064fbc7 100644
--- a/test/tint/buffer/uniform/std140/array/mat2x3_f16/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat2x3_f16/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f16_array_element {
   /* 0x0000 */ packed_half3 elements;
@@ -38,7 +39,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<tint_array<tint_packed_vec3_f16_array_element, 2>, 4>* const dest, tint_array<half2x3, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/array/mat2x3_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat2x3_f16/to_workgroup.wgsl.expected.msl
index 80b97c0..8a967df 100644
--- a/test/tint/buffer/uniform/std140/array/mat2x3_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat2x3_f16/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_7 {
   tint_array<half2x3, 4> w;
@@ -37,7 +38,7 @@
 }
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<half2x3, 4>* const tint_symbol, const constant tint_array<tint_array<tint_packed_vec3_f16_array_element, 2>, 4>* const tint_symbol_1, device half* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = half2x3(half3(0.0h), half3(0.0h));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat2x3_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat2x3_f32/to_storage.wgsl.expected.msl
index 6ca9dae..caa5898 100644
--- a/test/tint/buffer/uniform/std140/array/mat2x3_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat2x3_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f32_array_element {
   /* 0x0000 */ packed_float3 elements;
@@ -38,7 +39,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<tint_array<tint_packed_vec3_f32_array_element, 2>, 4>* const dest, tint_array<float2x3, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/array/mat2x3_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat2x3_f32/to_workgroup.wgsl.expected.msl
index 01ed488..90c28f4 100644
--- a/test/tint/buffer/uniform/std140/array/mat2x3_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat2x3_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<float2x3, 4> w;
@@ -37,7 +38,7 @@
 }
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<float2x3, 4>* const tint_symbol, const constant tint_array<tint_array<tint_packed_vec3_f32_array_element, 2>, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = float2x3(float3(0.0f), float3(0.0f));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat2x4_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat2x4_f16/to_workgroup.wgsl.expected.msl
index 4dd72bb..010d0e7 100644
--- a/test/tint/buffer/uniform/std140/array/mat2x4_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat2x4_f16/to_workgroup.wgsl.expected.msl

@@ -14,15 +14,16 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<half2x4, 4> w;
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<half2x4, 4>* const tint_symbol, const constant tint_array<half2x4, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = half2x4(half4(0.0h), half4(0.0h));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat2x4_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat2x4_f32/to_workgroup.wgsl.expected.msl
index 8219d90..642a8e1 100644
--- a/test/tint/buffer/uniform/std140/array/mat2x4_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat2x4_f32/to_workgroup.wgsl.expected.msl

@@ -14,15 +14,16 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<float2x4, 4> w;
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<float2x4, 4>* const tint_symbol, const constant tint_array<float2x4, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = float2x4(float4(0.0f), float4(0.0f));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat3x3_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat3x3_f32/to_storage.wgsl.expected.msl
index 084c472..774ab90 100644
--- a/test/tint/buffer/uniform/std140/array/mat3x3_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat3x3_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f32_array_element {
   /* 0x0000 */ packed_float3 elements;
@@ -39,7 +40,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<tint_array<tint_packed_vec3_f32_array_element, 3>, 4>* const dest, tint_array<float3x3, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/array/mat3x3_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat3x3_f32/to_workgroup.wgsl.expected.msl
index aacf68d..ade5401 100644
--- a/test/tint/buffer/uniform/std140/array/mat3x3_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat3x3_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<float3x3, 4> w;
@@ -37,7 +38,7 @@
 }
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<float3x3, 4>* const tint_symbol, const constant tint_array<tint_array<tint_packed_vec3_f32_array_element, 3>, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = float3x3(float3(0.0f), float3(0.0f), float3(0.0f));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat3x4_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat3x4_f32/to_workgroup.wgsl.expected.msl
index 7d93adf..5773552 100644
--- a/test/tint/buffer/uniform/std140/array/mat3x4_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat3x4_f32/to_workgroup.wgsl.expected.msl

@@ -14,15 +14,16 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<float3x4, 4> w;
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<float3x4, 4>* const tint_symbol, const constant tint_array<float3x4, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = float3x4(float4(0.0f), float4(0.0f), float4(0.0f));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat4x2_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat4x2_f16/to_workgroup.wgsl.expected.msl
index 9c7eb06..0814a7d 100644
--- a/test/tint/buffer/uniform/std140/array/mat4x2_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat4x2_f16/to_workgroup.wgsl.expected.msl

@@ -14,15 +14,16 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<half4x2, 4> w;
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<half4x2, 4>* const tint_symbol, const constant tint_array<half4x2, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = half4x2(half2(0.0h), half2(0.0h), half2(0.0h), half2(0.0h));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat4x2_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat4x2_f32/to_workgroup.wgsl.expected.msl
index 346f524..ba4fff3 100644
--- a/test/tint/buffer/uniform/std140/array/mat4x2_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat4x2_f32/to_workgroup.wgsl.expected.msl

@@ -14,15 +14,16 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<float4x2, 4> w;
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<float4x2, 4>* const tint_symbol, const constant tint_array<float4x2, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = float4x2(float2(0.0f), float2(0.0f), float2(0.0f), float2(0.0f));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat4x3_f16/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat4x3_f16/to_storage.wgsl.expected.msl
index b83bc68..4193d09 100644
--- a/test/tint/buffer/uniform/std140/array/mat4x3_f16/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat4x3_f16/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f16_array_element {
   /* 0x0000 */ packed_half3 elements;
@@ -40,7 +41,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<tint_array<tint_packed_vec3_f16_array_element, 4>, 4>* const dest, tint_array<half4x3, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/array/mat4x3_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat4x3_f16/to_workgroup.wgsl.expected.msl
index a887469..90a5714 100644
--- a/test/tint/buffer/uniform/std140/array/mat4x3_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat4x3_f16/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<half4x3, 4> w;
@@ -37,7 +38,7 @@
 }
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<half4x3, 4>* const tint_symbol, const constant tint_array<tint_array<tint_packed_vec3_f16_array_element, 4>, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = half4x3(half3(0.0h), half3(0.0h), half3(0.0h), half3(0.0h));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat4x3_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat4x3_f32/to_storage.wgsl.expected.msl
index 7891af0..3aa3e7d 100644
--- a/test/tint/buffer/uniform/std140/array/mat4x3_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat4x3_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f32_array_element {
   /* 0x0000 */ packed_float3 elements;
@@ -40,7 +41,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<tint_array<tint_packed_vec3_f32_array_element, 4>, 4>* const dest, tint_array<float4x3, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/array/mat4x3_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat4x3_f32/to_workgroup.wgsl.expected.msl
index efad62c..7c41b15 100644
--- a/test/tint/buffer/uniform/std140/array/mat4x3_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat4x3_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<float4x3, 4> w;
@@ -37,7 +38,7 @@
 }
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<float4x3, 4>* const tint_symbol, const constant tint_array<tint_array<tint_packed_vec3_f32_array_element, 4>, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = float4x3(float3(0.0f), float3(0.0f), float3(0.0f), float3(0.0f));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat4x4_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat4x4_f16/to_workgroup.wgsl.expected.msl
index 1a5b6c4..b6a330f 100644
--- a/test/tint/buffer/uniform/std140/array/mat4x4_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat4x4_f16/to_workgroup.wgsl.expected.msl

@@ -14,15 +14,16 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<half4x4, 4> w;
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<half4x4, 4>* const tint_symbol, const constant tint_array<half4x4, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = half4x4(half4(0.0h), half4(0.0h), half4(0.0h), half4(0.0h));
   }

diff --git a/test/tint/buffer/uniform/std140/array/mat4x4_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/array/mat4x4_f32/to_workgroup.wgsl.expected.msl
index d0a15df..d834d87 100644
--- a/test/tint/buffer/uniform/std140/array/mat4x4_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/array/mat4x4_f32/to_workgroup.wgsl.expected.msl

@@ -14,15 +14,16 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_5 {
   tint_array<float4x4, 4> w;
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<float4x4, 4>* const tint_symbol, const constant tint_array<float4x4, 4>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i] = float4x4(float4(0.0f), float4(0.0f), float4(0.0f), float4(0.0f));
   }

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x2_f16/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x2_f16/to_storage.wgsl.expected.msl
index b9955f2..cb8a8d8 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x2_f16/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x2_f16/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -32,7 +33,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x2_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x2_f16/to_workgroup.wgsl.expected.msl
index 5c82a33..4197aca 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x2_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x2_f16/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -30,7 +31,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x2_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x2_f32/to_storage.wgsl.expected.msl
index 34e488f..0084bbe 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x2_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x2_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -33,7 +34,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x2_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x2_f32/to_workgroup.wgsl.expected.msl
index 3f279dc..199abfb 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x2_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x2_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -31,7 +32,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x3_f16/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x3_f16/to_storage.wgsl.expected.msl
index 56713e0..2d8a663 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x3_f16/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x3_f16/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f16_array_element {
   /* 0x0000 */ packed_half3 elements;
@@ -67,7 +68,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S_tint_packed_vec3, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x3_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x3_f16/to_workgroup.wgsl.expected.msl
index 588aaab..2b3c31c 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x3_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x3_f16/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   int before;
@@ -60,7 +61,7 @@
 }
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S_tint_packed_vec3, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x3_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x3_f32/to_storage.wgsl.expected.msl
index ff079b0..6eac46f 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x3_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x3_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f32_array_element {
   /* 0x0000 */ packed_float3 elements;
@@ -67,7 +68,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S_tint_packed_vec3, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x3_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x3_f32/to_workgroup.wgsl.expected.msl
index d33bd36..589edbc 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x3_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x3_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   int before;
@@ -60,7 +61,7 @@
 }
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S_tint_packed_vec3, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x4_f16/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x4_f16/to_storage.wgsl.expected.msl
index ad499d1..ccc6b0a 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x4_f16/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x4_f16/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -33,7 +34,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x4_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x4_f16/to_workgroup.wgsl.expected.msl
index d159c8c..96d7dd3 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x4_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x4_f16/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -31,7 +32,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x4_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x4_f32/to_storage.wgsl.expected.msl
index 25e5698..ed35a67 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x4_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x4_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -33,7 +34,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat2x4_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat2x4_f32/to_workgroup.wgsl.expected.msl
index e5b4037..f23ac67 100644
--- a/test/tint/buffer/uniform/std140/struct/mat2x4_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat2x4_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -31,7 +32,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x2_f16/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x2_f16/to_storage.wgsl.expected.msl
index abdbcb8..805b281 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x2_f16/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x2_f16/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -32,7 +33,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x2_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x2_f16/to_workgroup.wgsl.expected.msl
index e42dc9b..8f15a71 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x2_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x2_f16/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -30,7 +31,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x2_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x2_f32/to_storage.wgsl.expected.msl
index 8044d64..005e620 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x2_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x2_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -33,7 +34,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x2_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x2_f32/to_workgroup.wgsl.expected.msl
index e48327d..34e4808 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x2_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x2_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -31,7 +32,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x3_f16/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x3_f16/to_storage.wgsl.expected.msl
index 82c29d0..655bc2d 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x3_f16/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x3_f16/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f16_array_element {
   /* 0x0000 */ packed_half3 elements;
@@ -68,7 +69,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S_tint_packed_vec3, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x3_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x3_f16/to_workgroup.wgsl.expected.msl
index 6933c8e..b3f3dc8 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x3_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x3_f16/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   int before;
@@ -60,7 +61,7 @@
 }
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S_tint_packed_vec3, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x3_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x3_f32/to_storage.wgsl.expected.msl
index b5946b4..07d8848 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x3_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x3_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f32_array_element {
   /* 0x0000 */ packed_float3 elements;
@@ -67,7 +68,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S_tint_packed_vec3, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x3_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x3_f32/to_workgroup.wgsl.expected.msl
index f97c99e..6c1cf8c 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x3_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x3_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   int before;
@@ -59,7 +60,7 @@
 }
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S_tint_packed_vec3, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x4_f16/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x4_f16/to_storage.wgsl.expected.msl
index 76fa2d8..71ee1ce 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x4_f16/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x4_f16/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -33,7 +34,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x4_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x4_f16/to_workgroup.wgsl.expected.msl
index be68271..f018f8f 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x4_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x4_f16/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -31,7 +32,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x4_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x4_f32/to_storage.wgsl.expected.msl
index cd77cae..4ca161f 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x4_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x4_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -32,7 +33,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat3x4_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat3x4_f32/to_workgroup.wgsl.expected.msl
index 82d11af..149aa04 100644
--- a/test/tint/buffer/uniform/std140/struct/mat3x4_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat3x4_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -30,7 +31,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x2_f16/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x2_f16/to_storage.wgsl.expected.msl
index f02b27e..9350b1f 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x2_f16/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x2_f16/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -32,7 +33,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x2_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x2_f16/to_workgroup.wgsl.expected.msl
index 5e57962..b58a037 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x2_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x2_f16/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -30,7 +31,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x2_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x2_f32/to_storage.wgsl.expected.msl
index 4713bde..f463cad 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x2_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x2_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -33,7 +34,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x2_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x2_f32/to_workgroup.wgsl.expected.msl
index 0f591ce..2c686d0 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x2_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x2_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -31,7 +32,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x3_f16/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x3_f16/to_storage.wgsl.expected.msl
index 752e4c5..a32e29f 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x3_f16/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x3_f16/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f16_array_element {
   /* 0x0000 */ packed_half3 elements;
@@ -69,7 +70,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S_tint_packed_vec3, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x3_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x3_f16/to_workgroup.wgsl.expected.msl
index 6428fa2..12f8a4c 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x3_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x3_f16/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   int before;
@@ -60,7 +61,7 @@
 }
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S_tint_packed_vec3, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x3_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x3_f32/to_storage.wgsl.expected.msl
index ec467fa..eebace9 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x3_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x3_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f32_array_element {
   /* 0x0000 */ packed_float3 elements;
@@ -69,7 +70,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S_tint_packed_vec3, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x3_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x3_f32/to_workgroup.wgsl.expected.msl
index 45ddab1..78c0ba8 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x3_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x3_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   int before;
@@ -60,7 +61,7 @@
 }
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S_tint_packed_vec3, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x4_f16/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x4_f16/to_storage.wgsl.expected.msl
index 69895c5..ed271f9 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x4_f16/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x4_f16/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -33,7 +34,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x4_f16/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x4_f16/to_workgroup.wgsl.expected.msl
index ad29c63..1fe454a 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x4_f16/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x4_f16/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -31,7 +32,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x4_f32/to_storage.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x4_f32/to_storage.wgsl.expected.msl
index 5153c38..e62b530 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x4_f32/to_storage.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x4_f32/to_storage.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -33,7 +34,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<S, 4>* const dest, tint_array<S, 4> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 4u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 4u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/buffer/uniform/std140/struct/mat4x4_f32/to_workgroup.wgsl.expected.msl b/test/tint/buffer/uniform/std140/struct/mat4x4_f32/to_workgroup.wgsl.expected.msl
index a97f92f..2d8ee79 100644
--- a/test/tint/buffer/uniform/std140/struct/mat4x4_f32/to_workgroup.wgsl.expected.msl
+++ b/test/tint/buffer/uniform/std140/struct/mat4x4_f32/to_workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   /* 0x0000 */ int before;
@@ -31,7 +32,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup tint_array<S, 4>* const tint_symbol_1, const constant tint_array<S, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     S const tint_symbol = S{};
     (*(tint_symbol_1))[i] = tint_symbol;

diff --git a/test/tint/bug/chromium/1403752.wgsl.expected.msl b/test/tint/bug/chromium/1403752.wgsl.expected.msl
index 7ae6187..4b4bc84 100644
--- a/test/tint/bug/chromium/1403752.wgsl.expected.msl
+++ b/test/tint/bug/chromium/1403752.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void d() {
   int j = 0;
-  TINT_ISOLATE_UB for(; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; false; ) {
   }
 }
 

diff --git a/test/tint/bug/chromium/1449538.wgsl.expected.msl b/test/tint/bug/chromium/1449538.wgsl.expected.msl
index c9600a2..f317e66 100644
--- a/test/tint/bug/chromium/1449538.wgsl.expected.msl
+++ b/test/tint/bug/chromium/1449538.wgsl.expected.msl

@@ -2,25 +2,26 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void f() {
-  TINT_ISOLATE_UB for(int i0520 = 0; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i0520 = 0; false; ) {
   }
-  TINT_ISOLATE_UB for(int i62 = 0; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(int i62 = 0; false; ) {
   }
-  TINT_ISOLATE_UB for(int i0520 = 0; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true_2) for(int i0520 = 0; false; ) {
   }
-  TINT_ISOLATE_UB for(int i62 = 0; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true_3) for(int i62 = 0; false; ) {
   }
-  TINT_ISOLATE_UB for(int i62 = 0; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true_4) for(int i62 = 0; false; ) {
   }
-  TINT_ISOLATE_UB for(int i60 = 0; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true_5) for(int i60 = 0; false; ) {
   }
-  TINT_ISOLATE_UB for(int i62 = 0; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true_6) for(int i62 = 0; false; ) {
   }
-  TINT_ISOLATE_UB for(int i60 = 0; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true_7) for(int i60 = 0; false; ) {
   }
 }
 

diff --git a/test/tint/bug/fxc/dyn_array_idx/read/workgroup.wgsl.expected.msl b/test/tint/bug/fxc/dyn_array_idx/read/workgroup.wgsl.expected.msl
index b14a8c8..a0b7b5d 100644
--- a/test/tint/bug/fxc/dyn_array_idx/read/workgroup.wgsl.expected.msl
+++ b/test/tint/bug/fxc/dyn_array_idx/read/workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct UBO {
   /* 0x0000 */ int dynamic_idx;
@@ -30,7 +31,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup S* const tint_symbol, device Result* const tint_symbol_1, const constant UBO* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 64u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 64u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol)).data[i] = 0;
   }

diff --git a/test/tint/bug/fxc/dyn_array_idx/write/workgroup.wgsl.expected.msl b/test/tint/bug/fxc/dyn_array_idx/write/workgroup.wgsl.expected.msl
index 3ac2c9d..34a9062 100644
--- a/test/tint/bug/fxc/dyn_array_idx/write/workgroup.wgsl.expected.msl
+++ b/test/tint/bug/fxc/dyn_array_idx/write/workgroup.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct UBO {
   /* 0x0000 */ int dynamic_idx;
@@ -30,7 +31,7 @@
 };
 
 void f_inner(uint local_invocation_index, threadgroup S* const tint_symbol, const constant UBO* const tint_symbol_1, device Result* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 64u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 64u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol)).data[i] = 0;
   }

diff --git a/test/tint/bug/fxc/gradient_in_varying_loop/1112.wgsl.expected.msl b/test/tint/bug/fxc/gradient_in_varying_loop/1112.wgsl.expected.msl
index 8a54b5e..d5797f0 100644
--- a/test/tint/bug/fxc/gradient_in_varying_loop/1112.wgsl.expected.msl
+++ b/test/tint/bug/fxc/gradient_in_varying_loop/1112.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_2 {
   float2 vUV [[user(locn0)]];
@@ -16,7 +17,7 @@
 float4 tint_symbol_inner(float2 vUV, texture2d<float, access::sample> tint_symbol_4, sampler tint_symbol_5) {
   float3 const random = tint_symbol_4.sample(tint_symbol_5, vUV).rgb;
   int i = 0;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if ((i < 1)) {
     } else {
       break;

diff --git a/test/tint/bug/fxc/vector_assignment_in_loop/loop_call_with_loop.wgsl.expected.msl b/test/tint/bug/fxc/vector_assignment_in_loop/loop_call_with_loop.wgsl.expected.msl
index da64fd9..54555c1 100644
--- a/test/tint/bug/fxc/vector_assignment_in_loop/loop_call_with_loop.wgsl.expected.msl
+++ b/test/tint/bug/fxc/vector_assignment_in_loop/loop_call_with_loop.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   float2 v2f;
@@ -13,7 +14,7 @@
 };
 
 void foo(thread tint_private_vars_struct* const tint_private_vars) {
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     (*(tint_private_vars)).v2f[i] = 1.0f;
     (*(tint_private_vars)).v3i[i] = 1;
     (*(tint_private_vars)).v4u[i] = 1u;
@@ -23,7 +24,7 @@
 
 kernel void tint_symbol() {
   thread tint_private_vars_struct tint_private_vars = {};
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     foo(&(tint_private_vars));
   }
   return;

diff --git a/test/tint/bug/fxc/vector_assignment_in_loop/loop_call_with_no_loop.wgsl.expected.msl b/test/tint/bug/fxc/vector_assignment_in_loop/loop_call_with_no_loop.wgsl.expected.msl
index af0bc02..0be7944 100644
--- a/test/tint/bug/fxc/vector_assignment_in_loop/loop_call_with_no_loop.wgsl.expected.msl
+++ b/test/tint/bug/fxc/vector_assignment_in_loop/loop_call_with_no_loop.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   float2 v2f;
@@ -22,7 +23,7 @@
 
 kernel void tint_symbol() {
   thread tint_private_vars_struct tint_private_vars = {};
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     foo(&(tint_private_vars));
   }
   return;

diff --git a/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_all.wgsl.expected.msl b/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_all.wgsl.expected.msl
index 0c01f6d..2304b9f 100644
--- a/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_all.wgsl.expected.msl
+++ b/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_all.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol() {
   float2 v2f = 0.0f;
@@ -18,7 +19,7 @@
   bool2 v2b = false;
   bool3 v3b = false;
   bool4 v4b = false;
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     v2f[i] = 1.0f;
     v3f[i] = 1.0f;
     v4f[i] = 1.0f;

diff --git a/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_repeated.wgsl.expected.msl b/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_repeated.wgsl.expected.msl
index e455d47..478a818 100644
--- a/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_repeated.wgsl.expected.msl
+++ b/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_repeated.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol() {
   float2 v2f = 0.0f;
@@ -14,7 +15,7 @@
   uint4 v4u_2 = 0u;
   bool2 v2b = false;
   bool2 v2b_2 = false;
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     v2f[i] = 1.0f;
     v3i[i] = 1;
     v4u[i] = 1u;

diff --git a/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_some.wgsl.expected.msl b/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_some.wgsl.expected.msl
index 1904207..3faf230 100644
--- a/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_some.wgsl.expected.msl
+++ b/test/tint/bug/fxc/vector_assignment_in_loop/loop_types_some.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol() {
   float2 v2f = 0.0f;
@@ -18,7 +19,7 @@
   bool2 v2b = false;
   bool3 v3b = false;
   bool4 v4b = false;
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     v2f[i] = 1.0f;
     v2i[i] = 1;
     v2u[i] = 1u;

diff --git a/test/tint/bug/tint/1064.wgsl.expected.msl b/test/tint/bug/tint/1064.wgsl.expected.msl
index 3b9997e..4ea4a7c 100644
--- a/test/tint/bug/tint/1064.wgsl.expected.msl
+++ b/test/tint/bug/tint/1064.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 fragment void tint_symbol() {
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if (false) {
     } else {
       break;

diff --git a/test/tint/bug/tint/1081.wgsl.expected.msl b/test/tint/bug/tint/1081.wgsl.expected.msl
index d1ab933..64f9887 100644
--- a/test/tint/bug/tint/1081.wgsl.expected.msl
+++ b/test/tint/bug/tint/1081.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   bool tint_discarded;
@@ -26,7 +27,7 @@
 
 int tint_symbol_inner(int3 x, thread tint_private_vars_struct* const tint_private_vars) {
   int y = x[0];
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     int const r = f(y, tint_private_vars);
     if ((r == 0)) {
       break;

diff --git a/test/tint/bug/tint/1121.wgsl.expected.msl b/test/tint/bug/tint/1121.wgsl.expected.msl
index 9f26018..bf996f9 100644
--- a/test/tint/bug/tint/1121.wgsl.expected.msl
+++ b/test/tint/bug/tint/1121.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct LightData_tint_packed_vec3 {
   /* 0x0000 */ float4 position;
@@ -87,8 +88,8 @@
   int const TILE_SIZE = 16;
   int const TILE_COUNT_X = 2;
   int const TILE_COUNT_Y = 2;
-  TINT_ISOLATE_UB for(int y = 0; (y < TILE_COUNT_Y); y = as_type<int>((as_type<uint>(y) + as_type<uint>(1)))) {
-    TINT_ISOLATE_UB for(int x = 0; (x < TILE_COUNT_X); x = as_type<int>((as_type<uint>(x) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int y = 0; (y < TILE_COUNT_Y); y = as_type<int>((as_type<uint>(y) + as_type<uint>(1)))) {
+    TINT_ISOLATE_UB(tint_volatile_true_1) for(int x = 0; (x < TILE_COUNT_X); x = as_type<int>((as_type<uint>(x) + as_type<uint>(1)))) {
       int2 tilePixel0Idx = int2(as_type<int>((as_type<uint>(x) * as_type<uint>(TILE_SIZE))), as_type<int>((as_type<uint>(y) * as_type<uint>(TILE_SIZE))));
       float2 floorCoord = (((2.0f * float2(tilePixel0Idx)) / (*(tint_symbol_3)).fullScreenSize.xy) - float2(1.0f));
       float2 ceilCoord = (((2.0f * float2(as_type<int2>((as_type<uint2>(tilePixel0Idx) + as_type<uint2>(int2(TILE_SIZE)))))) / (*(tint_symbol_3)).fullScreenSize.xy) - float2(1.0f));
@@ -99,7 +100,7 @@
       frustumPlanes[2] = float4(0.0f, 1.0f, (-(viewFloorCoord[1]) / viewNear), 0.0f);
       frustumPlanes[3] = float4(0.0f, -1.0f, (viewCeilCoord[1] / viewNear), 0.0f);
       float dp = 0.0f;
-      TINT_ISOLATE_UB for(uint i = 0u; (i < 6u); i = (i + 1u)) {
+      TINT_ISOLATE_UB(tint_volatile_true_2) for(uint i = 0u; (i < 6u); i = (i + 1u)) {
         float4 p = 0.0f;
         if ((frustumPlanes[i][0] > 0.0f)) {
           p[0] = boxMax[0];

diff --git a/test/tint/bug/tint/1321.wgsl.expected.msl b/test/tint/bug/tint/1321.wgsl.expected.msl
index 2d4a466..8dfe5a5 100644
--- a/test/tint/bug/tint/1321.wgsl.expected.msl
+++ b/test/tint/bug/tint/1321.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 int foo() {
   return 1;
@@ -26,7 +27,7 @@
   {
     int const tint_symbol_1 = foo();
     int const a_save = tint_symbol_1;
-    TINT_ISOLATE_UB while(true) {
+    TINT_ISOLATE_UB(tint_volatile_true) while(true) {
       {
         float const x = arr[a_save];
         break;

diff --git a/test/tint/bug/tint/1474-a.wgsl.expected.msl b/test/tint/bug/tint/1474-a.wgsl.expected.msl
index dda1010..4d8d438 100644
--- a/test/tint/bug/tint/1474-a.wgsl.expected.msl
+++ b/test/tint/bug/tint/1474-a.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol() {
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if (true) {
       break;
     } else {

diff --git a/test/tint/bug/tint/1538.wgsl.expected.msl b/test/tint/bug/tint/1538.wgsl.expected.msl
index bff79a4..87ec4d5 100644
--- a/test/tint/bug/tint/1538.wgsl.expected.msl
+++ b/test/tint/bug/tint/1538.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 template<typename T, size_t N>
 struct tint_array {
@@ -22,7 +23,7 @@
 }
 
 int f() {
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     g();
     break;
   }
@@ -31,7 +32,7 @@
 }
 
 kernel void tint_symbol(device tint_array<uint, 1>* tint_symbol_1 [[buffer(0)]]) {
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) while(true) {
     if (((*(tint_symbol_1))[0] == 0u)) {
       break;
     }

diff --git a/test/tint/bug/tint/1557.wgsl.expected.msl b/test/tint/bug/tint/1557.wgsl.expected.msl
index d47a9f9..c4a412f 100644
--- a/test/tint/bug/tint/1557.wgsl.expected.msl
+++ b/test/tint/bug/tint/1557.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 int f() {
   return 0;
@@ -11,7 +12,7 @@
 
 void g() {
   int j = 0;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if ((j >= 1)) {
       break;
     }

diff --git a/test/tint/bug/tint/1604.wgsl.expected.msl b/test/tint/bug/tint/1604.wgsl.expected.msl
index 10273a4..beb2f4d 100644
--- a/test/tint/bug/tint/1604.wgsl.expected.msl
+++ b/test/tint/bug/tint/1604.wgsl.expected.msl

@@ -2,13 +2,14 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol(const constant int* tint_symbol_1 [[buffer(0)]]) {
   switch(*(tint_symbol_1)) {
     case 0: {
-      TINT_ISOLATE_UB while(true) {
+      TINT_ISOLATE_UB(tint_volatile_true) while(true) {
         return;
       }
       break;

diff --git a/test/tint/bug/tint/1605.wgsl.expected.msl b/test/tint/bug/tint/1605.wgsl.expected.msl
index bface6e..86a658c 100644
--- a/test/tint/bug/tint/1605.wgsl.expected.msl
+++ b/test/tint/bug/tint/1605.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 bool func_3(const constant int* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(int i = 0; (i < *(tint_symbol_1)); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
-    TINT_ISOLATE_UB for(int j = -1; (j == 1); j = as_type<int>((as_type<uint>(j) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < *(tint_symbol_1)); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+    TINT_ISOLATE_UB(tint_volatile_true_1) for(int j = -1; (j == 1); j = as_type<int>((as_type<uint>(j) + as_type<uint>(1)))) {
       return false;
     }
   }

diff --git a/test/tint/bug/tint/1764.wgsl.expected.msl b/test/tint/bug/tint/1764.wgsl.expected.msl
index ded1dcc..c1e8f28 100644
--- a/test/tint/bug/tint/1764.wgsl.expected.msl
+++ b/test/tint/bug/tint/1764.wgsl.expected.msl

@@ -14,11 +14,12 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void tint_symbol_inner(uint local_invocation_index, threadgroup tint_array<int, 246>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 246u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 246u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol_1))[i] = 0;
   }

diff --git a/test/tint/bug/tint/2010.spvasm.expected.msl b/test/tint/bug/tint/2010.spvasm.expected.msl
index c528ebb..7b4aa0d 100644
--- a/test/tint/bug/tint/2010.spvasm.expected.msl
+++ b/test/tint/bug/tint/2010.spvasm.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   uint3 x_3;
@@ -49,7 +50,7 @@
   uint x_88 = 0u;
   uint const x_52 = (*(tint_private_vars)).x_3[0];
   x_54 = 0u;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     uint x_55 = 0u;
     x_58 = (*(tint_symbol_3)).field0.field0;
     if ((x_54 < x_58)) {
@@ -81,7 +82,7 @@
   }
   x_85 = x_76.xyxy;
   x_88 = 1u;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) while(true) {
     float4 x_111 = 0.0f;
     float4 x_86 = 0.0f;
     uint x_89 = 0u;
@@ -131,7 +132,7 @@
     atomic_store_explicit(tint_symbol_13, 0u, memory_order_relaxed);
     atomic_store_explicit(tint_symbol_14, 0u, memory_order_relaxed);
   }
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4096u); idx = (idx + 32u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_2) for(uint idx = local_invocation_index; (idx < 4096u); idx = (idx + 32u)) {
     uint const i = idx;
     S const tint_symbol_1 = S{};
     (*(tint_symbol_15))[i] = tint_symbol_1;

diff --git a/test/tint/bug/tint/2059.wgsl.expected.msl b/test/tint/bug/tint/2059.wgsl.expected.msl
index 3488383..5588ec6 100644
--- a/test/tint/bug/tint/2059.wgsl.expected.msl
+++ b/test/tint/bug/tint/2059.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_packed_vec3_f32_array_element {
   /* 0x0000 */ packed_float3 elements;
@@ -65,7 +66,7 @@
 }
 
 void assign_and_preserve_padding_3(device tint_array<tint_array<tint_packed_vec3_f32_array_element, 3>, 1>* const dest, tint_array<float3x3, 1> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 1u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 1u); i = (i + 1u)) {
     assign_and_preserve_padding(&((*(dest))[i]), value[i]);
   }
 }
@@ -79,7 +80,7 @@
 }
 
 void assign_and_preserve_padding_6(device tint_array<S_tint_packed_vec3, 1>* const dest, tint_array<S, 1> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 1u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(uint i = 0u; (i < 1u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }
@@ -89,14 +90,14 @@
 }
 
 void assign_and_preserve_padding_7(device tint_array<S2_tint_packed_vec3, 1>* const dest, tint_array<S2, 1> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 1u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_2) for(uint i = 0u; (i < 1u); i = (i + 1u)) {
     assign_and_preserve_padding_2(&((*(dest))[i]), value[i]);
   }
 }
 
 kernel void tint_symbol(device tint_array<tint_packed_vec3_f32_array_element, 3>* tint_symbol_8 [[buffer(0)]], device S_tint_packed_vec3* tint_symbol_9 [[buffer(1)]], device S2_tint_packed_vec3* tint_symbol_10 [[buffer(2)]], device S3_tint_packed_vec3* tint_symbol_11 [[buffer(3)]], device S4_tint_packed_vec3* tint_symbol_12 [[buffer(4)]], device tint_array<tint_array<tint_packed_vec3_f32_array_element, 3>, 1>* tint_symbol_13 [[buffer(5)]], device tint_array<S_tint_packed_vec3, 1>* tint_symbol_14 [[buffer(6)]], device tint_array<S2_tint_packed_vec3, 1>* tint_symbol_15 [[buffer(7)]]) {
   float3x3 m = float3x3(0.0f);
-  TINT_ISOLATE_UB for(uint c = 0u; (c < 3u); c = (c + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_3) for(uint c = 0u; (c < 3u); c = (c + 1u)) {
     m[c] = float3(float(((c * 3u) + 1u)), float(((c * 3u) + 2u)), float(((c * 3u) + 3u)));
   }
   {

diff --git a/test/tint/bug/tint/221.wgsl.expected.msl b/test/tint/bug/tint/221.wgsl.expected.msl
index 79c1851..c418ea4 100644
--- a/test/tint/bug/tint/221.wgsl.expected.msl
+++ b/test/tint/bug/tint/221.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct Buf {
   /* 0x0000 */ uint count;
@@ -28,7 +29,7 @@
 
 kernel void tint_symbol(device Buf* tint_symbol_1 [[buffer(0)]]) {
   uint i = 0u;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if ((i >= (*(tint_symbol_1)).count)) {
       break;
     }

diff --git a/test/tint/bug/tint/534.wgsl.expected.msl b/test/tint/bug/tint/534.wgsl.expected.msl
index 1594381..4a79dfc 100644
--- a/test/tint/bug/tint/534.wgsl.expected.msl
+++ b/test/tint/bug/tint/534.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 uint4 tint_ftou(float4 v) {
   return select(uint4(4294967295u), select(uint4(v), uint4(0u), (v < float4(0.0f))), (v < float4(4294967040.0f)));
@@ -48,7 +49,7 @@
   bool success = true;
   uint4 srcColorBits = 0u;
   uint4 dstColorBits = tint_ftou(dstColor);
-  TINT_ISOLATE_UB for(uint i = 0u; (i < (*(tint_symbol_3)).channelCount); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < (*(tint_symbol_3)).channelCount); i = (i + 1u)) {
     uint const tint_symbol_1 = i;
     srcColorBits[tint_symbol_1] = ConvertToFp16FloatValue(srcColor[i]);
     success = (success && (srcColorBits[i] == dstColorBits[i]));

diff --git a/test/tint/bug/tint/744.wgsl.expected.msl b/test/tint/bug/tint/744.wgsl.expected.msl
index 9300f34..ccb621f 100644
--- a/test/tint/bug/tint/744.wgsl.expected.msl
+++ b/test/tint/bug/tint/744.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct Uniforms {
   /* 0x0000 */ uint2 aShape;
@@ -32,7 +33,7 @@
   uint const dimInner = (*(tint_symbol_1)).aShape[1];
   uint const dimOutter = (*(tint_symbol_1)).outShape[1];
   uint result = 0u;
-  TINT_ISOLATE_UB for(uint i = 0u; (i < dimInner); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < dimInner); i = (i + 1u)) {
     uint const a = (i + (resultCell[0] * dimInner));
     uint const b = (resultCell[1] + (i * dimOutter));
     result = (result + ((*(tint_symbol_2)).numbers[a] * (*(tint_symbol_3)).numbers[b]));

diff --git a/test/tint/bug/tint/757.wgsl.expected.msl b/test/tint/bug/tint/757.wgsl.expected.msl
index b70aae4..b59e7b3 100644
--- a/test/tint/bug/tint/757.wgsl.expected.msl
+++ b/test/tint/bug/tint/757.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct Constants {
   int level;
@@ -29,7 +30,7 @@
   uint flatIndex = (((4u * GlobalInvocationID[2]) + (2u * GlobalInvocationID[1])) + GlobalInvocationID[0]);
   flatIndex = (flatIndex * 1u);
   float4 texel = tint_symbol_1.read(uint2(int2(GlobalInvocationID.xy)), 0, 0);
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 1u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 1u); i = (i + 1u)) {
     (*(tint_symbol_2)).values[(flatIndex + i)] = texel[0];
   }
 }

diff --git a/test/tint/bug/tint/914.wgsl.expected.msl b/test/tint/bug/tint/914.wgsl.expected.msl
index 2c3568d..7456ef8 100644
--- a/test/tint/bug/tint/914.wgsl.expected.msl
+++ b/test/tint/bug/tint/914.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct Uniforms {
   /* 0x0000 */ uint dimAOuter;
@@ -55,7 +56,7 @@
 }
 
 void tint_symbol_inner(uint3 local_id, uint3 global_id, uint local_invocation_index, threadgroup tint_array<tint_array<float, 64>, 64>* const tint_symbol_11, threadgroup tint_array<tint_array<float, 64>, 64>* const tint_symbol_12, const constant Uniforms* const tint_symbol_13, const device Matrix* const tint_symbol_14, const device Matrix* const tint_symbol_15, device Matrix* const tint_symbol_16) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4096u); idx = (idx + 256u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4096u); idx = (idx + 256u)) {
     uint const i = (idx / 64u);
     uint const i_1 = (idx % 64u);
     (*(tint_symbol_11))[i][i_1] = 0.0f;
@@ -70,16 +71,16 @@
   tint_array<float, 16> acc = {};
   float ACached = 0.0f;
   tint_array<float, 4> BCached = {};
-  TINT_ISOLATE_UB for(uint index = 0u; (index < 16u); index = (index + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(uint index = 0u; (index < 16u); index = (index + 1u)) {
     acc[index] = 0.0f;
   }
   uint const ColPerThreadA = 4u;
   uint const tileColA = (local_id[0] * ColPerThreadA);
   uint const RowPerThreadB = 4u;
   uint const tileRowB = (local_id[1] * RowPerThreadB);
-  TINT_ISOLATE_UB for(uint t = 0u; (t < numTiles); t = (t + 1u)) {
-    TINT_ISOLATE_UB for(uint innerRow = 0u; (innerRow < 4u); innerRow = (innerRow + 1u)) {
-      TINT_ISOLATE_UB for(uint innerCol = 0u; (innerCol < ColPerThreadA); innerCol = (innerCol + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_2) for(uint t = 0u; (t < numTiles); t = (t + 1u)) {
+    TINT_ISOLATE_UB(tint_volatile_true_3) for(uint innerRow = 0u; (innerRow < 4u); innerRow = (innerRow + 1u)) {
+      TINT_ISOLATE_UB(tint_volatile_true_4) for(uint innerCol = 0u; (innerCol < ColPerThreadA); innerCol = (innerCol + 1u)) {
         uint const inputRow = (tileRow + innerRow);
         uint const inputCol = (tileColA + innerCol);
         uint const tint_symbol_1 = inputRow;
@@ -87,8 +88,8 @@
         (*(tint_symbol_11))[tint_symbol_1][tint_symbol_2] = mm_readA((globalRow + innerRow), ((t * 64u) + inputCol), tint_symbol_13, tint_symbol_14);
       }
     }
-    TINT_ISOLATE_UB for(uint innerRow = 0u; (innerRow < RowPerThreadB); innerRow = (innerRow + 1u)) {
-      TINT_ISOLATE_UB for(uint innerCol = 0u; (innerCol < 4u); innerCol = (innerCol + 1u)) {
+    TINT_ISOLATE_UB(tint_volatile_true_5) for(uint innerRow = 0u; (innerRow < RowPerThreadB); innerRow = (innerRow + 1u)) {
+      TINT_ISOLATE_UB(tint_volatile_true_6) for(uint innerCol = 0u; (innerCol < 4u); innerCol = (innerCol + 1u)) {
         uint const inputRow = (tileRowB + innerRow);
         uint const inputCol = (tileCol + innerCol);
         uint const tint_symbol_3 = innerCol;
@@ -97,13 +98,13 @@
       }
     }
     threadgroup_barrier(mem_flags::mem_threadgroup);
-    TINT_ISOLATE_UB for(uint k = 0u; (k < 64u); k = (k + 1u)) {
-      TINT_ISOLATE_UB for(uint inner = 0u; (inner < 4u); inner = (inner + 1u)) {
+    TINT_ISOLATE_UB(tint_volatile_true_7) for(uint k = 0u; (k < 64u); k = (k + 1u)) {
+      TINT_ISOLATE_UB(tint_volatile_true_8) for(uint inner = 0u; (inner < 4u); inner = (inner + 1u)) {
         BCached[inner] = (*(tint_symbol_12))[k][(tileCol + inner)];
       }
-      TINT_ISOLATE_UB for(uint innerRow = 0u; (innerRow < 4u); innerRow = (innerRow + 1u)) {
+      TINT_ISOLATE_UB(tint_volatile_true_9) for(uint innerRow = 0u; (innerRow < 4u); innerRow = (innerRow + 1u)) {
         ACached = (*(tint_symbol_11))[(tileRow + innerRow)][k];
-        TINT_ISOLATE_UB for(uint innerCol = 0u; (innerCol < 4u); innerCol = (innerCol + 1u)) {
+        TINT_ISOLATE_UB(tint_volatile_true_10) for(uint innerCol = 0u; (innerCol < 4u); innerCol = (innerCol + 1u)) {
           uint const index = ((innerRow * 4u) + innerCol);
           acc[index] = (acc[index] + (ACached * BCached[innerCol]));
         }
@@ -111,8 +112,8 @@
     }
     threadgroup_barrier(mem_flags::mem_threadgroup);
   }
-  TINT_ISOLATE_UB for(uint innerRow = 0u; (innerRow < 4u); innerRow = (innerRow + 1u)) {
-    TINT_ISOLATE_UB for(uint innerCol = 0u; (innerCol < 4u); innerCol = (innerCol + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_11) for(uint innerRow = 0u; (innerRow < 4u); innerRow = (innerRow + 1u)) {
+    TINT_ISOLATE_UB(tint_volatile_true_12) for(uint innerCol = 0u; (innerCol < 4u); innerCol = (innerCol + 1u)) {
       uint const index = ((innerRow * 4u) + innerCol);
       mm_write((globalRow + innerRow), (globalCol + innerCol), acc[index], tint_symbol_13, tint_symbol_16);
     }

diff --git a/test/tint/bug/tint/942.wgsl.expected.msl b/test/tint/bug/tint/942.wgsl.expected.msl
index 7a7d361..0e2fc15 100644
--- a/test/tint/bug/tint/942.wgsl.expected.msl
+++ b/test/tint/bug/tint/942.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct Params {
   /* 0x0000 */ uint filterDim;
@@ -31,7 +32,7 @@
 }
 
 void tint_symbol_inner(uint3 WorkGroupID, uint3 LocalInvocationID, uint local_invocation_index, threadgroup tint_array<tint_array<float3, 256>, 4>* const tint_symbol_1, const constant Params* const tint_symbol_2, texture2d<float, access::sample> tint_symbol_3, const constant Flip* const tint_symbol_4, sampler tint_symbol_5, texture2d<float, access::write> tint_symbol_6) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 1024u); idx = (idx + 64u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 1024u); idx = (idx + 64u)) {
     uint const i_1 = (idx / 256u);
     uint const i_2 = (idx % 256u);
     (*(tint_symbol_1))[i_1][i_2] = float3(0.0f);
@@ -40,8 +41,8 @@
   uint const filterOffset = tint_div(((*(tint_symbol_2)).filterDim - 1u), 2u);
   uint2 const dims = uint2(tint_symbol_3.get_width(0), tint_symbol_3.get_height(0));
   uint2 const baseIndex = (((WorkGroupID.xy * uint2((*(tint_symbol_2)).blockDim, 4u)) + (LocalInvocationID.xy * uint2(4u, 1u))) - uint2(filterOffset, 0u));
-  TINT_ISOLATE_UB for(uint r = 0u; (r < 4u); r = (r + 1u)) {
-    TINT_ISOLATE_UB for(uint c = 0u; (c < 4u); c = (c + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(uint r = 0u; (r < 4u); r = (r + 1u)) {
+    TINT_ISOLATE_UB(tint_volatile_true_2) for(uint c = 0u; (c < 4u); c = (c + 1u)) {
       uint2 loadIndex = (baseIndex + uint2(c, r));
       if (((*(tint_symbol_4)).value != 0u)) {
         loadIndex = loadIndex.yx;
@@ -50,8 +51,8 @@
     }
   }
   threadgroup_barrier(mem_flags::mem_threadgroup);
-  TINT_ISOLATE_UB for(uint r = 0u; (r < 4u); r = (r + 1u)) {
-    TINT_ISOLATE_UB for(uint c = 0u; (c < 4u); c = (c + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_3) for(uint r = 0u; (r < 4u); r = (r + 1u)) {
+    TINT_ISOLATE_UB(tint_volatile_true_4) for(uint c = 0u; (c < 4u); c = (c + 1u)) {
       uint2 writeIndex = (baseIndex + uint2(c, r));
       if (((*(tint_symbol_4)).value != 0u)) {
         writeIndex = writeIndex.yx;
@@ -59,7 +60,7 @@
       uint const center = ((4u * LocalInvocationID[0]) + c);
       if ((((center >= filterOffset) && (center < (256u - filterOffset))) && all((writeIndex < dims)))) {
         float3 acc = float3(0.0f);
-        TINT_ISOLATE_UB for(uint f = 0u; (f < (*(tint_symbol_2)).filterDim); f = (f + 1u)) {
+        TINT_ISOLATE_UB(tint_volatile_true_5) for(uint f = 0u; (f < (*(tint_symbol_2)).filterDim); f = (f + 1u)) {
           uint i = ((center + f) - filterOffset);
           acc = (acc + ((1.0f / float((*(tint_symbol_2)).filterDim)) * (*(tint_symbol_1))[r][i]));
         }

diff --git a/test/tint/bug/tint/948.wgsl.expected.msl b/test/tint/bug/tint/948.wgsl.expected.msl
index 0047f1c..cc95fb8 100644
--- a/test/tint/bug/tint/948.wgsl.expected.msl
+++ b/test/tint/bug/tint/948.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   float2 tUV;
@@ -101,7 +102,7 @@
   float2 const x_111 = (*(tint_symbol_8)).stageSize;
   stageUnits = (float2(1.0f) / x_111);
   i = 0;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     int const x_122 = i;
     if ((x_122 < 2)) {
     } else {
@@ -137,7 +138,7 @@
       float const x_184 = animationData[2];
       (*(tint_private_vars)).mt = fmod((x_181 * x_184), 1.0f);
       f = 0.0f;
-      TINT_ISOLATE_UB while(true) {
+      TINT_ISOLATE_UB(tint_volatile_true_1) while(true) {
         float const x_193 = f;
         if ((x_193 < 8.0f)) {
         } else {

diff --git a/test/tint/bug/tint/949.wgsl.expected.msl b/test/tint/bug/tint/949.wgsl.expected.msl
index d8b8c4f..b832adc6 100644
--- a/test/tint/bug/tint/949.wgsl.expected.msl
+++ b/test/tint/bug/tint/949.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   float u_Float;
@@ -333,7 +334,7 @@
   lastSampledHeight = 1.0f;
   currSampledHeight = 1.0f;
   i = 0;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     int const x_388 = i;
     if ((x_388 < 15)) {
     } else {

diff --git a/test/tint/bug/tint/990.wgsl.expected.msl b/test/tint/bug/tint/990.wgsl.expected.msl
index ec5a232..09a7dbc 100644
--- a/test/tint/bug/tint/990.wgsl.expected.msl
+++ b/test/tint/bug/tint/990.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void f() {
   int i = 0;
-  TINT_ISOLATE_UB for(; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; false; ) {
   }
 }
 

diff --git a/test/tint/builtins/atomicStore/array/aliased_arrays.spvasm.expected.msl b/test/tint/builtins/atomicStore/array/aliased_arrays.spvasm.expected.msl
index 9c324b7..e009490 100644
--- a/test/tint/builtins/atomicStore/array/aliased_arrays.spvasm.expected.msl
+++ b/test/tint/builtins/atomicStore/array/aliased_arrays.spvasm.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   uint local_invocation_index_1;
@@ -32,7 +33,7 @@
 void compute_main_inner(uint local_invocation_index_2, threadgroup tint_array<tint_array<tint_array<atomic_uint, 1>, 2>, 3>* const tint_symbol) {
   uint idx = 0u;
   idx = local_invocation_index_2;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if (!((idx < 6u))) {
       break;
     }
@@ -56,7 +57,7 @@
 }
 
 void compute_main_inner_1(uint local_invocation_index_1_param, thread tint_private_vars_struct* const tint_private_vars, threadgroup tint_array<tint_array<tint_array<atomic_uint, 1>, 2>, 3>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx_1 = local_invocation_index_1_param; (idx_1 < 6u); idx_1 = (idx_1 + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(uint idx_1 = local_invocation_index_1_param; (idx_1 < 6u); idx_1 = (idx_1 + 1u)) {
     uint const i = (idx_1 / 2u);
     uint const i_1 = (idx_1 % 2u);
     uint const i_2 = (idx_1 % 1u);

diff --git a/test/tint/builtins/atomicStore/array/aliased_arrays.wgsl.expected.msl b/test/tint/builtins/atomicStore/array/aliased_arrays.wgsl.expected.msl
index 3ae828f..b568170 100644
--- a/test/tint/builtins/atomicStore/array/aliased_arrays.wgsl.expected.msl
+++ b/test/tint/builtins/atomicStore/array/aliased_arrays.wgsl.expected.msl

@@ -14,11 +14,12 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void compute_main_inner(uint local_invocation_index, threadgroup tint_array<tint_array<tint_array<atomic_uint, 1>, 2>, 3>* const tint_symbol) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 6u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 6u); idx = (idx + 1u)) {
     uint const i = (idx / 2u);
     uint const i_1 = (idx % 2u);
     uint const i_2 = (idx % 1u);

diff --git a/test/tint/builtins/atomicStore/array/array.spvasm.expected.msl b/test/tint/builtins/atomicStore/array/array.spvasm.expected.msl
index 312a5cf..16afbf7 100644
--- a/test/tint/builtins/atomicStore/array/array.spvasm.expected.msl
+++ b/test/tint/builtins/atomicStore/array/array.spvasm.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   uint local_invocation_index_1;
@@ -24,7 +25,7 @@
 void compute_main_inner(uint local_invocation_index_2, threadgroup tint_array<atomic_uint, 4>* const tint_symbol) {
   uint idx = 0u;
   idx = local_invocation_index_2;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if (!((idx < 4u))) {
       break;
     }
@@ -46,7 +47,7 @@
 }
 
 void compute_main_inner_1(uint local_invocation_index_1_param, thread tint_private_vars_struct* const tint_private_vars, threadgroup tint_array<atomic_uint, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx_1 = local_invocation_index_1_param; (idx_1 < 4u); idx_1 = (idx_1 + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(uint idx_1 = local_invocation_index_1_param; (idx_1 < 4u); idx_1 = (idx_1 + 1u)) {
     uint const i = idx_1;
     atomic_store_explicit(&((*(tint_symbol_2))[i]), 0u, memory_order_relaxed);
   }

diff --git a/test/tint/builtins/atomicStore/array/array.wgsl.expected.msl b/test/tint/builtins/atomicStore/array/array.wgsl.expected.msl
index d5d5e27..9477dfb 100644
--- a/test/tint/builtins/atomicStore/array/array.wgsl.expected.msl
+++ b/test/tint/builtins/atomicStore/array/array.wgsl.expected.msl

@@ -14,11 +14,12 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void compute_main_inner(uint local_invocation_index, threadgroup tint_array<atomic_uint, 4>* const tint_symbol) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     atomic_store_explicit(&((*(tint_symbol))[i]), 0u, memory_order_relaxed);
   }

diff --git a/test/tint/builtins/atomicStore/array/arrays.spvasm.expected.msl b/test/tint/builtins/atomicStore/array/arrays.spvasm.expected.msl
index 9c324b7..e009490 100644
--- a/test/tint/builtins/atomicStore/array/arrays.spvasm.expected.msl
+++ b/test/tint/builtins/atomicStore/array/arrays.spvasm.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   uint local_invocation_index_1;
@@ -32,7 +33,7 @@
 void compute_main_inner(uint local_invocation_index_2, threadgroup tint_array<tint_array<tint_array<atomic_uint, 1>, 2>, 3>* const tint_symbol) {
   uint idx = 0u;
   idx = local_invocation_index_2;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if (!((idx < 6u))) {
       break;
     }
@@ -56,7 +57,7 @@
 }
 
 void compute_main_inner_1(uint local_invocation_index_1_param, thread tint_private_vars_struct* const tint_private_vars, threadgroup tint_array<tint_array<tint_array<atomic_uint, 1>, 2>, 3>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx_1 = local_invocation_index_1_param; (idx_1 < 6u); idx_1 = (idx_1 + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(uint idx_1 = local_invocation_index_1_param; (idx_1 < 6u); idx_1 = (idx_1 + 1u)) {
     uint const i = (idx_1 / 2u);
     uint const i_1 = (idx_1 % 2u);
     uint const i_2 = (idx_1 % 1u);

diff --git a/test/tint/builtins/atomicStore/array/arrays.wgsl.expected.msl b/test/tint/builtins/atomicStore/array/arrays.wgsl.expected.msl
index 3ae828f..b568170 100644
--- a/test/tint/builtins/atomicStore/array/arrays.wgsl.expected.msl
+++ b/test/tint/builtins/atomicStore/array/arrays.wgsl.expected.msl

@@ -14,11 +14,12 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void compute_main_inner(uint local_invocation_index, threadgroup tint_array<tint_array<tint_array<atomic_uint, 1>, 2>, 3>* const tint_symbol) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 6u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 6u); idx = (idx + 1u)) {
     uint const i = (idx / 2u);
     uint const i_1 = (idx % 2u);
     uint const i_2 = (idx % 1u);

diff --git a/test/tint/builtins/atomicStore/struct/array_of_struct.spvasm.expected.msl b/test/tint/builtins/atomicStore/struct/array_of_struct.spvasm.expected.msl
index 431c5c2..858e4d9 100644
--- a/test/tint/builtins/atomicStore/struct/array_of_struct.spvasm.expected.msl
+++ b/test/tint/builtins/atomicStore/struct/array_of_struct.spvasm.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   uint local_invocation_index_1;
@@ -36,7 +37,7 @@
 void compute_main_inner(uint local_invocation_index_2, threadgroup tint_array<S_atomic, 10>* const tint_symbol) {
   uint idx = 0u;
   idx = local_invocation_index_2;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if (!((idx < 10u))) {
       break;
     }
@@ -60,7 +61,7 @@
 }
 
 void compute_main_inner_1(uint local_invocation_index_1_param, thread tint_private_vars_struct* const tint_private_vars, threadgroup tint_array<S_atomic, 10>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx_1 = local_invocation_index_1_param; (idx_1 < 10u); idx_1 = (idx_1 + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(uint idx_1 = local_invocation_index_1_param; (idx_1 < 10u); idx_1 = (idx_1 + 1u)) {
     uint const i = idx_1;
     (*(tint_symbol_2))[i].x = 0;
     atomic_store_explicit(&((*(tint_symbol_2))[i].a), 0u, memory_order_relaxed);

diff --git a/test/tint/builtins/atomicStore/struct/array_of_struct.wgsl.expected.msl b/test/tint/builtins/atomicStore/struct/array_of_struct.wgsl.expected.msl
index 04d1917..bef111c 100644
--- a/test/tint/builtins/atomicStore/struct/array_of_struct.wgsl.expected.msl
+++ b/test/tint/builtins/atomicStore/struct/array_of_struct.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   int x;
@@ -24,7 +25,7 @@
 };
 
 void compute_main_inner(uint local_invocation_index, threadgroup tint_array<S, 10>* const tint_symbol) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 10u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 10u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol))[i].x = 0;
     atomic_store_explicit(&((*(tint_symbol))[i].a), 0u, memory_order_relaxed);

diff --git a/test/tint/builtins/atomicStore/struct/struct_of_array.spvasm.expected.msl b/test/tint/builtins/atomicStore/struct/struct_of_array.spvasm.expected.msl
index 1e6af34..1ca5272 100644
--- a/test/tint/builtins/atomicStore/struct/struct_of_array.spvasm.expected.msl
+++ b/test/tint/builtins/atomicStore/struct/struct_of_array.spvasm.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   uint local_invocation_index_1;
@@ -38,7 +39,7 @@
   (*(tint_symbol)).x = 0;
   (*(tint_symbol)).y = 0u;
   idx = local_invocation_index_2;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if (!((idx < 10u))) {
       break;
     }
@@ -64,7 +65,7 @@
     (*(tint_symbol_2)).x = 0;
     (*(tint_symbol_2)).y = 0u;
   }
-  TINT_ISOLATE_UB for(uint idx_1 = local_invocation_index_1_param; (idx_1 < 10u); idx_1 = (idx_1 + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true_1) for(uint idx_1 = local_invocation_index_1_param; (idx_1 < 10u); idx_1 = (idx_1 + 1u)) {
     uint const i = idx_1;
     atomic_store_explicit(&((*(tint_symbol_2)).a[i]), 0u, memory_order_relaxed);
   }

diff --git a/test/tint/builtins/atomicStore/struct/struct_of_array.wgsl.expected.msl b/test/tint/builtins/atomicStore/struct/struct_of_array.wgsl.expected.msl
index ad1e165..487589e 100644
--- a/test/tint/builtins/atomicStore/struct/struct_of_array.wgsl.expected.msl
+++ b/test/tint/builtins/atomicStore/struct/struct_of_array.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   int x;
@@ -28,7 +29,7 @@
     (*(tint_symbol)).x = 0;
     (*(tint_symbol)).y = 0u;
   }
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 10u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 10u); idx = (idx + 1u)) {
     uint const i = idx;
     atomic_store_explicit(&((*(tint_symbol)).a[i]), 0u, memory_order_relaxed);
   }

diff --git a/test/tint/builtins/textureStore/loop_continuing_read_write_texture.wgsl.expected.msl b/test/tint/builtins/textureStore/loop_continuing_read_write_texture.wgsl.expected.msl
index 2242f0f..9d7fb7d 100644
--- a/test/tint/builtins/textureStore/loop_continuing_read_write_texture.wgsl.expected.msl
+++ b/test/tint/builtins/textureStore/loop_continuing_read_write_texture.wgsl.expected.msl

@@ -2,13 +2,14 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void foo(texture2d<int, access::read_write> tint_symbol) {
   {
     int i = 0;
-    TINT_ISOLATE_UB while(true) {
+    TINT_ISOLATE_UB(tint_volatile_true) while(true) {
       if (!((i < 3))) {
         break;
       }

diff --git a/test/tint/builtins/workgroupUniformLoad/for_loop.wgsl.expected.msl b/test/tint/builtins/workgroupUniformLoad/for_loop.wgsl.expected.msl
index b840f6f..5a52532 100644
--- a/test/tint/builtins/workgroupUniformLoad/for_loop.wgsl.expected.msl
+++ b/test/tint/builtins/workgroupUniformLoad/for_loop.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 int tint_workgroupUniformLoad(threadgroup int* const p) {
   threadgroup_barrier(mem_flags::mem_threadgroup);
@@ -15,7 +16,7 @@
 void foo(threadgroup int* const tint_symbol_4, threadgroup int* const tint_symbol_5) {
   {
     int i = 0;
-    TINT_ISOLATE_UB while(true) {
+    TINT_ISOLATE_UB(tint_volatile_true) while(true) {
       int const tint_symbol = i;
       int const tint_symbol_1 = tint_workgroupUniformLoad(tint_symbol_4);
       if (!((tint_symbol < tint_symbol_1))) {

diff --git a/test/tint/diagnostic_filtering/for_loop_attribute.wgsl.expected.msl b/test/tint/diagnostic_filtering/for_loop_attribute.wgsl.expected.msl
index 071ba03..63a1789 100644
--- a/test/tint/diagnostic_filtering/for_loop_attribute.wgsl.expected.msl
+++ b/test/tint/diagnostic_filtering/for_loop_attribute.wgsl.expected.msl

@@ -14,8 +14,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_2 {
   float x [[user(locn0)]];
@@ -23,7 +24,7 @@
 
 void tint_symbol_inner(float x) {
   float4 v = float4(0.0f);
-  TINT_ISOLATE_UB for(; ((x > v[0]) && (dfdx(1.0f) > 0.0f)); ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; ((x > v[0]) && (dfdx(1.0f) > 0.0f)); ) {
   }
 }
 

diff --git a/test/tint/diagnostic_filtering/for_loop_body_attribute.wgsl.expected.msl b/test/tint/diagnostic_filtering/for_loop_body_attribute.wgsl.expected.msl
index f410fb6..68189b2 100644
--- a/test/tint/diagnostic_filtering/for_loop_body_attribute.wgsl.expected.msl
+++ b/test/tint/diagnostic_filtering/for_loop_body_attribute.wgsl.expected.msl

@@ -14,8 +14,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_2 {
   float x [[user(locn0)]];
@@ -23,7 +24,7 @@
 
 void tint_symbol_inner(float x, texture2d<float, access::sample> tint_symbol_3, sampler tint_symbol_4) {
   float4 v = float4(0.0f);
-  TINT_ISOLATE_UB for(; (x > v[0]); ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; (x > v[0]); ) {
     v = tint_symbol_3.sample(tint_symbol_4, float2(0.0f));
   }
 }

diff --git a/test/tint/diagnostic_filtering/loop_attribute.wgsl.expected.msl b/test/tint/diagnostic_filtering/loop_attribute.wgsl.expected.msl
index 3dae810..e8e448f 100644
--- a/test/tint/diagnostic_filtering/loop_attribute.wgsl.expected.msl
+++ b/test/tint/diagnostic_filtering/loop_attribute.wgsl.expected.msl

@@ -14,15 +14,16 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_2 {
   float x [[user(locn0)]];
 };
 
 void tint_symbol_inner(float x) {
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     {
       if ((x > 0.0f)) { break; }
     }

diff --git a/test/tint/diagnostic_filtering/loop_body_attribute.wgsl.expected.msl b/test/tint/diagnostic_filtering/loop_body_attribute.wgsl.expected.msl
index 602c64b..1d37883 100644
--- a/test/tint/diagnostic_filtering/loop_body_attribute.wgsl.expected.msl
+++ b/test/tint/diagnostic_filtering/loop_body_attribute.wgsl.expected.msl

@@ -14,15 +14,16 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_2 {
   float x [[user(locn0)]];
 };
 
 void tint_symbol_inner(float x) {
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     {
       if ((x > 0.0f)) { break; }
     }

diff --git a/test/tint/diagnostic_filtering/loop_continuing_attribute.wgsl.expected.msl b/test/tint/diagnostic_filtering/loop_continuing_attribute.wgsl.expected.msl
index 38499a3..93fca0d 100644
--- a/test/tint/diagnostic_filtering/loop_continuing_attribute.wgsl.expected.msl
+++ b/test/tint/diagnostic_filtering/loop_continuing_attribute.wgsl.expected.msl

@@ -14,15 +14,16 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_2 {
   float x [[user(locn0)]];
 };
 
 void tint_symbol_inner(float x) {
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     {
       if ((x > 0.0f)) { break; }
     }

diff --git a/test/tint/diagnostic_filtering/while_loop_attribute.wgsl.expected.msl b/test/tint/diagnostic_filtering/while_loop_attribute.wgsl.expected.msl
index 2c394d5..686748f 100644
--- a/test/tint/diagnostic_filtering/while_loop_attribute.wgsl.expected.msl
+++ b/test/tint/diagnostic_filtering/while_loop_attribute.wgsl.expected.msl

@@ -14,8 +14,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_2 {
   float x [[user(locn0)]];
@@ -23,7 +24,7 @@
 
 void tint_symbol_inner(float x) {
   float4 v = float4(0.0f);
-  TINT_ISOLATE_UB while(((x > 0.0f) && (dfdx(1.0f) > 0.0f))) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(((x > 0.0f) && (dfdx(1.0f) > 0.0f))) {
   }
 }
 

diff --git a/test/tint/diagnostic_filtering/while_loop_body_attribute.wgsl.expected.msl b/test/tint/diagnostic_filtering/while_loop_body_attribute.wgsl.expected.msl
index 649759e..b2e7ce2 100644
--- a/test/tint/diagnostic_filtering/while_loop_body_attribute.wgsl.expected.msl
+++ b/test/tint/diagnostic_filtering/while_loop_body_attribute.wgsl.expected.msl

@@ -14,8 +14,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_2 {
   float x [[user(locn0)]];
@@ -23,7 +24,7 @@
 
 void tint_symbol_inner(float x, texture2d<float, access::sample> tint_symbol_3, sampler tint_symbol_4) {
   float4 v = float4(0.0f);
-  TINT_ISOLATE_UB while((x > v[0])) {
+  TINT_ISOLATE_UB(tint_volatile_true) while((x > v[0])) {
     v = tint_symbol_3.sample(tint_symbol_4, float2(0.0f));
   }
 }

diff --git a/test/tint/layout/storage/mat2x2/stride/16.spvasm.expected.msl b/test/tint/layout/storage/mat2x2/stride/16.spvasm.expected.msl
index d82e019..74e58e2 100644
--- a/test/tint/layout/storage/mat2x2/stride/16.spvasm.expected.msl
+++ b/test/tint/layout/storage/mat2x2/stride/16.spvasm.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct strided_arr {
   /* 0x0000 */ float2 el;
@@ -42,7 +43,7 @@
 }
 
 void assign_and_preserve_padding(device tint_array<strided_arr, 2>* const dest, tint_array<strided_arr, 2> value) {
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 2u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 2u); i = (i + 1u)) {
     assign_and_preserve_padding_1(&((*(dest))[i]), value[i]);
   }
 }

diff --git a/test/tint/loops/continue_in_switch.wgsl.expected.msl b/test/tint/loops/continue_in_switch.wgsl.expected.msl
index e2991a3..890daca 100644
--- a/test/tint/loops/continue_in_switch.wgsl.expected.msl
+++ b/test/tint/loops/continue_in_switch.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void f() {
-  TINT_ISOLATE_UB for(int i = 0; (i < 4); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 4); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     switch(i) {
       case 0: {
         continue;

diff --git a/test/tint/loops/loop.wgsl.expected.msl b/test/tint/loops/loop.wgsl.expected.msl
index b26d512..3ab3d8e 100644
--- a/test/tint/loops/loop.wgsl.expected.msl
+++ b/test/tint/loops/loop.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 int f() {
   int i = 0;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)));
     if ((i > 4)) {
       return i;

diff --git a/test/tint/loops/loop_with_break_if.wgsl.expected.msl b/test/tint/loops/loop_with_break_if.wgsl.expected.msl
index 1344663..08f6c09 100644
--- a/test/tint/loops/loop_with_break_if.wgsl.expected.msl
+++ b/test/tint/loops/loop_with_break_if.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 int f() {
   int i = 0;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if ((i > 4)) {
       return i;
     }

diff --git a/test/tint/loops/loop_with_continuing.wgsl.expected.msl b/test/tint/loops/loop_with_continuing.wgsl.expected.msl
index 024d5b9..2f3b467 100644
--- a/test/tint/loops/loop_with_continuing.wgsl.expected.msl
+++ b/test/tint/loops/loop_with_continuing.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 int f() {
   int i = 0;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if ((i > 4)) {
       return i;
     }

diff --git a/test/tint/loops/multiple_continues.wgsl.expected.msl b/test/tint/loops/multiple_continues.wgsl.expected.msl
index 803ee58..f8aaba6 100644
--- a/test/tint/loops/multiple_continues.wgsl.expected.msl
+++ b/test/tint/loops/multiple_continues.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol() {
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     switch(i) {
       case 0: {
         continue;

diff --git a/test/tint/loops/multiple_switch.wgsl.expected.msl b/test/tint/loops/multiple_switch.wgsl.expected.msl
index 5becfcc..0bad249 100644
--- a/test/tint/loops/multiple_switch.wgsl.expected.msl
+++ b/test/tint/loops/multiple_switch.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol() {
   int i = 0;
-  TINT_ISOLATE_UB for(int i_1 = 0; (i_1 < 2); i_1 = as_type<int>((as_type<uint>(i_1) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i_1 = 0; (i_1 < 2); i_1 = as_type<int>((as_type<uint>(i_1) + as_type<uint>(1)))) {
     switch(i_1) {
       case 0: {
         continue;

diff --git a/test/tint/loops/nested_loop_loop_switch.wgsl.expected.msl b/test/tint/loops/nested_loop_loop_switch.wgsl.expected.msl
index 01dd258..8940027 100644
--- a/test/tint/loops/nested_loop_loop_switch.wgsl.expected.msl
+++ b/test/tint/loops/nested_loop_loop_switch.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol() {
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(2)))) {
-    TINT_ISOLATE_UB for(int j = 0; (j < 2); j = as_type<int>((as_type<uint>(j) + as_type<uint>(2)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(2)))) {
+    TINT_ISOLATE_UB(tint_volatile_true_1) for(int j = 0; (j < 2); j = as_type<int>((as_type<uint>(j) + as_type<uint>(2)))) {
       switch(i) {
         case 0: {
           continue;

diff --git a/test/tint/loops/nested_loop_switch_loop_switch.wgsl.expected.msl b/test/tint/loops/nested_loop_switch_loop_switch.wgsl.expected.msl
index e4d3cb7..2662928 100644
--- a/test/tint/loops/nested_loop_switch_loop_switch.wgsl.expected.msl
+++ b/test/tint/loops/nested_loop_switch_loop_switch.wgsl.expected.msl

@@ -2,14 +2,15 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol() {
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(2)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(2)))) {
     switch(i) {
       case 0: {
-        TINT_ISOLATE_UB for(int j = 0; (j < 2); j = as_type<int>((as_type<uint>(j) + as_type<uint>(2)))) {
+        TINT_ISOLATE_UB(tint_volatile_true_1) for(int j = 0; (j < 2); j = as_type<int>((as_type<uint>(j) + as_type<uint>(2)))) {
           switch(j) {
             case 0: {
               continue;

diff --git a/test/tint/loops/nested_loop_switch_loop_switch_switch.wgsl.expected.msl b/test/tint/loops/nested_loop_switch_loop_switch_switch.wgsl.expected.msl
index 5aa6cb9..47f158b 100644
--- a/test/tint/loops/nested_loop_switch_loop_switch_switch.wgsl.expected.msl
+++ b/test/tint/loops/nested_loop_switch_loop_switch_switch.wgsl.expected.msl

@@ -2,15 +2,16 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol() {
   int k = 0;
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(2)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(2)))) {
     switch(i) {
       case 0: {
-        TINT_ISOLATE_UB for(int j = 0; (j < 2); j = as_type<int>((as_type<uint>(j) + as_type<uint>(2)))) {
+        TINT_ISOLATE_UB(tint_volatile_true_1) for(int j = 0; (j < 2); j = as_type<int>((as_type<uint>(j) + as_type<uint>(2)))) {
           switch(j) {
             case 0: {
               continue;

diff --git a/test/tint/loops/nested_loop_switch_switch.wgsl.expected.msl b/test/tint/loops/nested_loop_switch_switch.wgsl.expected.msl
index 1adeeb0..0f78ee3 100644
--- a/test/tint/loops/nested_loop_switch_switch.wgsl.expected.msl
+++ b/test/tint/loops/nested_loop_switch_switch.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol() {
   int j = 0;
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(2)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(2)))) {
     switch(i) {
       case 0: {
         switch(j) {

diff --git a/test/tint/loops/nested_loops.wgsl.expected.msl b/test/tint/loops/nested_loops.wgsl.expected.msl
index 3c0a637..8f176cb 100644
--- a/test/tint/loops/nested_loops.wgsl.expected.msl
+++ b/test/tint/loops/nested_loops.wgsl.expected.msl

@@ -2,18 +2,19 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 int f() {
   int i = 0;
   int j = 0;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)));
     if ((i > 4)) {
       return 1;
     }
-    TINT_ISOLATE_UB while(true) {
+    TINT_ISOLATE_UB(tint_volatile_true_1) while(true) {
       j = as_type<int>((as_type<uint>(j) + as_type<uint>(1)));
       if ((j > 4)) {
         return 2;

diff --git a/test/tint/loops/nested_loops_with_continuing.wgsl.expected.msl b/test/tint/loops/nested_loops_with_continuing.wgsl.expected.msl
index 000b361..25ea8bc 100644
--- a/test/tint/loops/nested_loops_with_continuing.wgsl.expected.msl
+++ b/test/tint/loops/nested_loops_with_continuing.wgsl.expected.msl

@@ -2,17 +2,18 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 int f() {
   int i = 0;
   int j = 0;
-  TINT_ISOLATE_UB while(true) {
+  TINT_ISOLATE_UB(tint_volatile_true) while(true) {
     if ((i > 4)) {
       return 1;
     }
-    TINT_ISOLATE_UB while(true) {
+    TINT_ISOLATE_UB(tint_volatile_true_1) while(true) {
       if ((j > 4)) {
         return 2;
       }

diff --git a/test/tint/loops/single_continue.wgsl.expected.msl b/test/tint/loops/single_continue.wgsl.expected.msl
index f321a4b..e223c34 100644
--- a/test/tint/loops/single_continue.wgsl.expected.msl
+++ b/test/tint/loops/single_continue.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 kernel void tint_symbol() {
-  TINT_ISOLATE_UB for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 2); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     switch(i) {
       case 0: {
         continue;

diff --git a/test/tint/loops/while.wgsl.expected.msl b/test/tint/loops/while.wgsl.expected.msl
index f7428f9..d044fb0 100644
--- a/test/tint/loops/while.wgsl.expected.msl
+++ b/test/tint/loops/while.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 int f() {
   int i = 0;
-  TINT_ISOLATE_UB while((i < 4)) {
+  TINT_ISOLATE_UB(tint_volatile_true) while((i < 4)) {
     i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)));
   }
   return i;

diff --git a/test/tint/loops/while_with_continue.wgsl.expected.msl b/test/tint/loops/while_with_continue.wgsl.expected.msl
index 65fe6f5..35233d4 100644
--- a/test/tint/loops/while_with_continue.wgsl.expected.msl
+++ b/test/tint/loops/while_with_continue.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 int f() {
   int i = 0;
-  TINT_ISOLATE_UB while((i < 4)) {
+  TINT_ISOLATE_UB(tint_volatile_true) while((i < 4)) {
     i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)));
     continue;
   }

diff --git a/test/tint/ptr_ref/load/param/workgroup/array_in_struct.wgsl.expected.msl b/test/tint/ptr_ref/load/param/workgroup/array_in_struct.wgsl.expected.msl
index 457eb5c..cc8c3ec 100644
--- a/test/tint/ptr_ref/load/param/workgroup/array_in_struct.wgsl.expected.msl
+++ b/test/tint/ptr_ref/load/param/workgroup/array_in_struct.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct str {
   tint_array<int, 4> arr;
@@ -26,7 +27,7 @@
 }
 
 void tint_symbol_inner(uint local_invocation_index, threadgroup str* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol_1)).arr[i] = 0;
   }

diff --git a/test/tint/ptr_ref/load/param/workgroup/struct_in_array.wgsl.expected.msl b/test/tint/ptr_ref/load/param/workgroup/struct_in_array.wgsl.expected.msl
index 91fb413..bfeeb54 100644
--- a/test/tint/ptr_ref/load/param/workgroup/struct_in_array.wgsl.expected.msl
+++ b/test/tint/ptr_ref/load/param/workgroup/struct_in_array.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct str {
   int i;
@@ -26,7 +27,7 @@
 }
 
 void tint_symbol_inner(uint local_invocation_index, threadgroup tint_array<str, 4>* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i_1 = idx;
     str const tint_symbol_1 = str{};
     (*(tint_symbol_2))[i_1] = tint_symbol_1;

diff --git a/test/tint/ptr_ref/store/param/workgroup/array_in_struct.wgsl.expected.msl b/test/tint/ptr_ref/store/param/workgroup/array_in_struct.wgsl.expected.msl
index 140b544..eea4b36 100644
--- a/test/tint/ptr_ref/store/param/workgroup/array_in_struct.wgsl.expected.msl
+++ b/test/tint/ptr_ref/store/param/workgroup/array_in_struct.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct str {
   tint_array<int, 4> arr;
@@ -27,7 +28,7 @@
 }
 
 void tint_symbol_inner(uint local_invocation_index, threadgroup str* const tint_symbol_2) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol_2)).arr[i] = 0;
   }

diff --git a/test/tint/ptr_ref/store/param/workgroup/struct_in_array.wgsl.expected.msl b/test/tint/ptr_ref/store/param/workgroup/struct_in_array.wgsl.expected.msl
index 054a738..ef74323 100644
--- a/test/tint/ptr_ref/store/param/workgroup/struct_in_array.wgsl.expected.msl
+++ b/test/tint/ptr_ref/store/param/workgroup/struct_in_array.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct str {
   int i;
@@ -27,7 +28,7 @@
 }
 
 void tint_symbol_inner(uint local_invocation_index, threadgroup tint_array<str, 4>* const tint_symbol_3) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 4u); idx = (idx + 1u)) {
     uint const i_1 = idx;
     str const tint_symbol_1 = str{};
     (*(tint_symbol_3))[i_1] = tint_symbol_1;

diff --git a/test/tint/samples/compute_boids.wgsl.expected.msl b/test/tint/samples/compute_boids.wgsl.expected.msl
index cec623c..e64ec48 100644
--- a/test/tint/samples/compute_boids.wgsl.expected.msl
+++ b/test/tint/samples/compute_boids.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_symbol_1 {
   float2 a_particlePos [[attribute(0)]];
@@ -88,7 +89,7 @@
   int cVelCount = 0;
   float2 pos = 0.0f;
   float2 vel = 0.0f;
-  TINT_ISOLATE_UB for(uint i = 0u; (i < 5u); i = (i + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint i = 0u; (i < 5u); i = (i + 1u)) {
     if ((i == index)) {
       continue;
     }

diff --git a/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_body.wgsl.expected.msl b/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_body.wgsl.expected.msl
index 6972c31..091fcb0 100644
--- a/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_body.wgsl.expected.msl
+++ b/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_body.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct Uniforms {
   /* 0x0000 */ uint i;
@@ -32,7 +33,7 @@
 kernel void tint_symbol(const constant Uniforms* tint_symbol_1 [[buffer(0)]]) {
   InnerS v = {};
   OuterS s1 = {};
-  TINT_ISOLATE_UB for(int i = 0; (i < 4); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 4); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     s1.a1[(*(tint_symbol_1)).i] = v;
   }
   return;

diff --git a/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_continuing.wgsl.expected.msl b/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_continuing.wgsl.expected.msl
index 1bbb83c..884c030 100644
--- a/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_continuing.wgsl.expected.msl
+++ b/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_continuing.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct Uniforms {
   /* 0x0000 */ uint i;
@@ -32,7 +33,7 @@
 kernel void tint_symbol(const constant Uniforms* tint_symbol_1 [[buffer(0)]]) {
   InnerS v = {};
   OuterS s1 = {};
-  TINT_ISOLATE_UB for(int i = 0; (i < 4); s1.a1[(*(tint_symbol_1)).i] = v) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 4); s1.a1[(*(tint_symbol_1)).i] = v) {
     i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)));
   }
   return;

diff --git a/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_init.wgsl.expected.msl b/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_init.wgsl.expected.msl
index db29e84..4431501 100644
--- a/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_init.wgsl.expected.msl
+++ b/test/tint/statements/assign/indexed_assign_to_array_in_struct/in_for_loop_init.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct Uniforms {
   /* 0x0000 */ uint i;
@@ -33,7 +34,7 @@
   InnerS v = {};
   OuterS s1 = {};
   int i = 0;
-  TINT_ISOLATE_UB for(s1.a1[(*(tint_symbol_1)).i] = v; (i < 4); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(s1.a1[(*(tint_symbol_1)).i] = v; (i < 4); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
   }
   return;
 }

diff --git a/test/tint/statements/compound_assign/for_loop.wgsl.expected.msl b/test/tint/statements/compound_assign/for_loop.wgsl.expected.msl
index 4a7047b..190496d 100644
--- a/test/tint/statements/compound_assign/for_loop.wgsl.expected.msl
+++ b/test/tint/statements/compound_assign/for_loop.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   uint i;
@@ -48,7 +49,7 @@
     int const tint_symbol_2 = idx1(tint_private_vars);
     int const tint_symbol_save = tint_symbol_2;
     a[tint_symbol_save] = (a[tint_symbol_save] * 2.0f);
-    TINT_ISOLATE_UB while(true) {
+    TINT_ISOLATE_UB(tint_volatile_true) while(true) {
       int const tint_symbol_3 = idx2(tint_private_vars);
       if (!((a[tint_symbol_3] < 10.0f))) {
         break;

diff --git a/test/tint/statements/decrement/complex.wgsl.expected.msl b/test/tint/statements/decrement/complex.wgsl.expected.msl
index 49634f7..e31aa32 100644
--- a/test/tint/statements/decrement/complex.wgsl.expected.msl
+++ b/test/tint/statements/decrement/complex.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   uint v;
@@ -63,7 +64,7 @@
     int const tint_symbol_2_save_1 = tint_symbol_7;
     int const tint_symbol_3 = idx3(tint_private_vars);
     (*(tint_symbol_10))[tint_symbol_2_save].a[tint_symbol_2_save_1][tint_symbol_3] = as_type<int>((as_type<uint>((*(tint_symbol_10))[tint_symbol_2_save].a[tint_symbol_2_save_1][tint_symbol_3]) - as_type<uint>(1)));
-    TINT_ISOLATE_UB while(true) {
+    TINT_ISOLATE_UB(tint_volatile_true) while(true) {
       if (!(((*(tint_private_vars)).v < 10u))) {
         break;
       }

diff --git a/test/tint/statements/decrement/for_loop_continuing.wgsl.expected.msl b/test/tint/statements/decrement/for_loop_continuing.wgsl.expected.msl
index 195cf52..46ba1a3 100644
--- a/test/tint/statements/decrement/for_loop_continuing.wgsl.expected.msl
+++ b/test/tint/statements/decrement/for_loop_continuing.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void tint_symbol(device uint* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(; (*(tint_symbol_1) < 10u); *(tint_symbol_1) = (*(tint_symbol_1) - 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; (*(tint_symbol_1) < 10u); *(tint_symbol_1) = (*(tint_symbol_1) - 1u)) {
   }
 }
 

diff --git a/test/tint/statements/decrement/for_loop_initializer.wgsl.expected.msl b/test/tint/statements/decrement/for_loop_initializer.wgsl.expected.msl
index bee2a0c..53fcca7 100644
--- a/test/tint/statements/decrement/for_loop_initializer.wgsl.expected.msl
+++ b/test/tint/statements/decrement/for_loop_initializer.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void tint_symbol(device uint* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(*(tint_symbol_1) = (*(tint_symbol_1) - 1u); (*(tint_symbol_1) < 10u); ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(*(tint_symbol_1) = (*(tint_symbol_1) - 1u); (*(tint_symbol_1) < 10u); ) {
   }
 }
 

diff --git a/test/tint/statements/discard/atomic_in_for_loop_continuing.wgsl.expected.msl b/test/tint/statements/discard/atomic_in_for_loop_continuing.wgsl.expected.msl
index 9316b19..75776fc 100644
--- a/test/tint/statements/discard/atomic_in_for_loop_continuing.wgsl.expected.msl
+++ b/test/tint/statements/discard/atomic_in_for_loop_continuing.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   bool tint_discarded;
@@ -29,7 +30,7 @@
   int result = tint_ftoi(tint_symbol_4.sample(tint_symbol_5, coord)[0]);
   {
     int i = 0;
-    TINT_ISOLATE_UB while(true) {
+    TINT_ISOLATE_UB(tint_volatile_true) while(true) {
       if (!((i < 10))) {
         break;
       }

diff --git a/test/tint/statements/discard/multiple_returns.wgsl.expected.msl b/test/tint/statements/discard/multiple_returns.wgsl.expected.msl
index 6eac933..281e9bb 100644
--- a/test/tint/statements/discard/multiple_returns.wgsl.expected.msl
+++ b/test/tint/statements/discard/multiple_returns.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   bool tint_discarded;
@@ -20,7 +21,7 @@
   }
   if ((*(tint_symbol_2) < 0.0f)) {
     int i = 0;
-    TINT_ISOLATE_UB while(true) {
+    TINT_ISOLATE_UB(tint_volatile_true) while(true) {
       if ((*(tint_symbol_2) > float(i))) {
         if (!(tint_private_vars.tint_discarded)) {
           *(tint_symbol_2) = float(i);

diff --git a/test/tint/statements/for/basic.wgsl.expected.msl b/test/tint/statements/for/basic.wgsl.expected.msl
index ecdaaf5..d43d02c 100644
--- a/test/tint/statements/for/basic.wgsl.expected.msl
+++ b/test/tint/statements/for/basic.wgsl.expected.msl

@@ -2,14 +2,15 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void some_loop_body() {
 }
 
 void f() {
-  TINT_ISOLATE_UB for(int i = 0; (i < 5); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; (i < 5); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     some_loop_body();
   }
 }

diff --git a/test/tint/statements/for/complex.wgsl.expected.msl b/test/tint/statements/for/complex.wgsl.expected.msl
index 38b2dcb..a33d5d0 100644
--- a/test/tint/statements/for/complex.wgsl.expected.msl
+++ b/test/tint/statements/for/complex.wgsl.expected.msl

@@ -2,15 +2,16 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void some_loop_body() {
 }
 
 void f() {
   int j = 0;
-  TINT_ISOLATE_UB for(int i = 0; ((i < 5) && (j < 10)); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; ((i < 5) && (j < 10)); i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
     some_loop_body();
     j = as_type<int>((as_type<uint>(i) * as_type<uint>(30)));
   }

diff --git a/test/tint/statements/for/condition/array_ctor.wgsl.expected.msl b/test/tint/statements/for/condition/array_ctor.wgsl.expected.msl
index 225ca95..1ff0ed4 100644
--- a/test/tint/statements/for/condition/array_ctor.wgsl.expected.msl
+++ b/test/tint/statements/for/condition/array_ctor.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void f() {
   int i = 0;
-  TINT_ISOLATE_UB for(; (i < 1); ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; (i < 1); ) {
   }
 }
 

diff --git a/test/tint/statements/for/condition/basic.wgsl.expected.msl b/test/tint/statements/for/condition/basic.wgsl.expected.msl
index 9e4d48b..960d032 100644
--- a/test/tint/statements/for/condition/basic.wgsl.expected.msl
+++ b/test/tint/statements/for/condition/basic.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void f() {
   int i = 0;
-  TINT_ISOLATE_UB for(; (i < 4); ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; (i < 4); ) {
   }
 }
 

diff --git a/test/tint/statements/for/condition/struct_ctor.wgsl.expected.msl b/test/tint/statements/for/condition/struct_ctor.wgsl.expected.msl
index 1ce1740..848e21b 100644
--- a/test/tint/statements/for/condition/struct_ctor.wgsl.expected.msl
+++ b/test/tint/statements/for/condition/struct_ctor.wgsl.expected.msl

@@ -2,8 +2,9 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   int i;
@@ -11,7 +12,7 @@
 
 void f() {
   int i = 0;
-  TINT_ISOLATE_UB for(; (i < 1); ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; (i < 1); ) {
   }
 }
 

diff --git a/test/tint/statements/for/continuing/array_ctor.wgsl.expected.msl b/test/tint/statements/for/continuing/array_ctor.wgsl.expected.msl
index 91eff5e8..f40f0a7 100644
--- a/test/tint/statements/for/continuing/array_ctor.wgsl.expected.msl
+++ b/test/tint/statements/for/continuing/array_ctor.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void f() {
   int i = 0;
-  TINT_ISOLATE_UB for(; false; i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; false; i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
   }
 }
 

diff --git a/test/tint/statements/for/continuing/basic.wgsl.expected.msl b/test/tint/statements/for/continuing/basic.wgsl.expected.msl
index 91eff5e8..f40f0a7 100644
--- a/test/tint/statements/for/continuing/basic.wgsl.expected.msl
+++ b/test/tint/statements/for/continuing/basic.wgsl.expected.msl

@@ -2,12 +2,13 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void f() {
   int i = 0;
-  TINT_ISOLATE_UB for(; false; i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; false; i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
   }
 }
 

diff --git a/test/tint/statements/for/continuing/struct_ctor.wgsl.expected.msl b/test/tint/statements/for/continuing/struct_ctor.wgsl.expected.msl
index 6b5fe78..549cf31 100644
--- a/test/tint/statements/for/continuing/struct_ctor.wgsl.expected.msl
+++ b/test/tint/statements/for/continuing/struct_ctor.wgsl.expected.msl

@@ -2,15 +2,16 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   int i;
 };
 
 void f() {
-  TINT_ISOLATE_UB for(int i = 0; false; i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; false; i = as_type<int>((as_type<uint>(i) + as_type<uint>(1)))) {
   }
 }
 

diff --git a/test/tint/statements/for/empty.wgsl.expected.msl b/test/tint/statements/for/empty.wgsl.expected.msl
index 92bb29d..3637121 100644
--- a/test/tint/statements/for/empty.wgsl.expected.msl
+++ b/test/tint/statements/for/empty.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void f() {
-  TINT_ISOLATE_UB for(; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; false; ) {
   }
 }
 

diff --git a/test/tint/statements/for/initializer/array_ctor.wgsl.expected.msl b/test/tint/statements/for/initializer/array_ctor.wgsl.expected.msl
index e9d4bc4..5caf7e9 100644
--- a/test/tint/statements/for/initializer/array_ctor.wgsl.expected.msl
+++ b/test/tint/statements/for/initializer/array_ctor.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void f() {
-  TINT_ISOLATE_UB for(int i = 1; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 1; false; ) {
   }
 }
 

diff --git a/test/tint/statements/for/initializer/basic.wgsl.expected.msl b/test/tint/statements/for/initializer/basic.wgsl.expected.msl
index f1ec896..d8c6ba5 100644
--- a/test/tint/statements/for/initializer/basic.wgsl.expected.msl
+++ b/test/tint/statements/for/initializer/basic.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void f() {
-  TINT_ISOLATE_UB for(int i = 0; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 0; false; ) {
   }
 }
 

diff --git a/test/tint/statements/for/initializer/struct_ctor.wgsl.expected.msl b/test/tint/statements/for/initializer/struct_ctor.wgsl.expected.msl
index 1af8e13..3afd169 100644
--- a/test/tint/statements/for/initializer/struct_ctor.wgsl.expected.msl
+++ b/test/tint/statements/for/initializer/struct_ctor.wgsl.expected.msl

@@ -2,15 +2,16 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct S {
   int i;
 };
 
 void f() {
-  TINT_ISOLATE_UB for(int i = 1; false; ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int i = 1; false; ) {
   }
 }
 

diff --git a/test/tint/statements/for/scoping.wgsl.expected.msl b/test/tint/statements/for/scoping.wgsl.expected.msl
index 74c7f3b..7ac803c 100644
--- a/test/tint/statements/for/scoping.wgsl.expected.msl
+++ b/test/tint/statements/for/scoping.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void f() {
-  TINT_ISOLATE_UB for(int must_not_collide = 0; ; ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(int must_not_collide = 0; ; ) {
     break;
   }
   int must_not_collide = 0;

diff --git a/test/tint/statements/increment/complex.wgsl.expected.msl b/test/tint/statements/increment/complex.wgsl.expected.msl
index 9f7b0fa..8ed663a 100644
--- a/test/tint/statements/increment/complex.wgsl.expected.msl
+++ b/test/tint/statements/increment/complex.wgsl.expected.msl

@@ -14,8 +14,9 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 struct tint_private_vars_struct {
   uint v;
@@ -63,7 +64,7 @@
     int const tint_symbol_2_save_1 = tint_symbol_7;
     int const tint_symbol_3 = idx3(tint_private_vars);
     (*(tint_symbol_10))[tint_symbol_2_save].a[tint_symbol_2_save_1][tint_symbol_3] = as_type<int>((as_type<uint>((*(tint_symbol_10))[tint_symbol_2_save].a[tint_symbol_2_save_1][tint_symbol_3]) + as_type<uint>(1)));
-    TINT_ISOLATE_UB while(true) {
+    TINT_ISOLATE_UB(tint_volatile_true) while(true) {
       if (!(((*(tint_private_vars)).v < 10u))) {
         break;
       }

diff --git a/test/tint/statements/increment/for_loop_continuing.wgsl.expected.msl b/test/tint/statements/increment/for_loop_continuing.wgsl.expected.msl
index e452d03..c3f779c 100644
--- a/test/tint/statements/increment/for_loop_continuing.wgsl.expected.msl
+++ b/test/tint/statements/increment/for_loop_continuing.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void tint_symbol(device uint* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(; (*(tint_symbol_1) < 10u); *(tint_symbol_1) = (*(tint_symbol_1) + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(; (*(tint_symbol_1) < 10u); *(tint_symbol_1) = (*(tint_symbol_1) + 1u)) {
   }
 }
 

diff --git a/test/tint/statements/increment/for_loop_initializer.wgsl.expected.msl b/test/tint/statements/increment/for_loop_initializer.wgsl.expected.msl
index f46177a..53257b5 100644
--- a/test/tint/statements/increment/for_loop_initializer.wgsl.expected.msl
+++ b/test/tint/statements/increment/for_loop_initializer.wgsl.expected.msl

@@ -2,11 +2,12 @@
 
 using namespace metal;
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void tint_symbol(device uint* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(*(tint_symbol_1) = (*(tint_symbol_1) + 1u); (*(tint_symbol_1) < 10u); ) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(*(tint_symbol_1) = (*(tint_symbol_1) + 1u); (*(tint_symbol_1) < 10u); ) {
   }
 }
 

diff --git a/test/tint/var/initialization/workgroup/array/array_i32.wgsl.expected.msl b/test/tint/var/initialization/workgroup/array/array_i32.wgsl.expected.msl
index 37f33b9..53b0d79 100644
--- a/test/tint/var/initialization/workgroup/array/array_i32.wgsl.expected.msl
+++ b/test/tint/var/initialization/workgroup/array/array_i32.wgsl.expected.msl

@@ -14,11 +14,12 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void tint_symbol_inner(uint local_invocation_index, threadgroup tint_array<tint_array<int, 3>, 2>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 6u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 6u); idx = (idx + 1u)) {
     uint const i = (idx / 3u);
     uint const i_1 = (idx % 3u);
     (*(tint_symbol_1))[i][i_1] = 0;

diff --git a/test/tint/var/initialization/workgroup/array/i32.wgsl.expected.msl b/test/tint/var/initialization/workgroup/array/i32.wgsl.expected.msl
index a1ca997..6039b69 100644
--- a/test/tint/var/initialization/workgroup/array/i32.wgsl.expected.msl
+++ b/test/tint/var/initialization/workgroup/array/i32.wgsl.expected.msl

@@ -14,11 +14,12 @@
     T elements[N];
 };
 
-#define TINT_ISOLATE_UB \
-  if (volatile bool tint_volatile_true = true; tint_volatile_true)
+#define TINT_ISOLATE_UB(VOLATILE_NAME) \
+  volatile bool VOLATILE_NAME = true; \
+  if (VOLATILE_NAME)
 
 void tint_symbol_inner(uint local_invocation_index, threadgroup tint_array<int, 3>* const tint_symbol_1) {
-  TINT_ISOLATE_UB for(uint idx = local_invocation_index; (idx < 3u); idx = (idx + 1u)) {
+  TINT_ISOLATE_UB(tint_volatile_true) for(uint idx = local_invocation_index; (idx < 3u); idx = (idx + 1u)) {
     uint const i = idx;
     (*(tint_symbol_1))[i] = 0;
   }