[spirv-reader] Add ArrayStride

Bug: tint:3
Change-Id: Ib174795d1b055b33bfc94205173dbc5a88bb92cb
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/23262
Reviewed-by: dan sinclair <dsinclair@google.com>
diff --git a/src/reader/spirv/parser_impl.cc b/src/reader/spirv/parser_impl.cc
index 870bd79..c90a620 100644
--- a/src/reader/spirv/parser_impl.cc
+++ b/src/reader/spirv/parser_impl.cc
@@ -589,18 +589,19 @@
 
 ast::type::Type* ParserImpl::ConvertType(
     const spvtools::opt::analysis::RuntimeArray* rtarr_ty) {
-  // TODO(dneto): Handle ArrayStride. Blocked by crbug.com/tint/30
   auto* ast_elem_ty = ConvertType(type_mgr_->GetId(rtarr_ty->element_type()));
   if (ast_elem_ty == nullptr) {
     return nullptr;
   }
-  return ctx_.type_mgr().Get(
-      std::make_unique<ast::type::ArrayType>(ast_elem_ty));
+  auto ast_type = std::make_unique<ast::type::ArrayType>(ast_elem_ty);
+  if (!ApplyArrayDecorations(rtarr_ty, ast_type.get())) {
+    return nullptr;
+  }
+  return ctx_.type_mgr().Get(std::move(ast_type));
 }
 
 ast::type::Type* ParserImpl::ConvertType(
     const spvtools::opt::analysis::Array* arr_ty) {
-  // TODO(dneto): Handle ArrayStride. Blocked by crbug.com/tint/30
   auto* ast_elem_ty = ConvertType(type_mgr_->GetId(arr_ty->element_type()));
   if (ast_elem_ty == nullptr) {
     return nullptr;
@@ -632,8 +633,39 @@
            << num_elem;
     return nullptr;
   }
-  return ctx_.type_mgr().Get(std::make_unique<ast::type::ArrayType>(
-      ast_elem_ty, static_cast<uint32_t>(num_elem)));
+  auto ast_type = std::make_unique<ast::type::ArrayType>(
+      ast_elem_ty, static_cast<uint32_t>(num_elem));
+  if (!ApplyArrayDecorations(arr_ty, ast_type.get())) {
+    return nullptr;
+  }
+  return ctx_.type_mgr().Get(std::move(ast_type));
+}
+
+bool ParserImpl::ApplyArrayDecorations(
+    const spvtools::opt::analysis::Type* spv_type,
+    ast::type::ArrayType* ast_type) {
+  const auto type_id = type_mgr_->GetId(spv_type);
+  for (auto& decoration : this->GetDecorationsFor(type_id)) {
+    if (decoration.size() == 2 && decoration[0] == SpvDecorationArrayStride) {
+      const auto stride = decoration[1];
+      if (stride == 0) {
+        return Fail() << "invalid array type ID " << type_id
+                      << ": ArrayStride can't be 0";
+      }
+      if (ast_type->has_array_stride()) {
+        return Fail() << "invalid array type ID " << type_id
+                      << ": multiple ArrayStride decorations";
+      }
+      ast_type->set_array_stride(stride);
+    } else {
+      return Fail() << "invalid array type ID " << type_id
+                    << ": unknown decoration "
+                    << (decoration.empty() ? "(empty)"
+                                           : std::to_string(decoration[0]))
+                    << " with " << decoration.size() << " total words";
+    }
+  }
+  return true;
 }
 
 ast::type::Type* ParserImpl::ConvertType(
diff --git a/src/reader/spirv/parser_impl.h b/src/reader/spirv/parser_impl.h
index 4a4e70d..b269455 100644
--- a/src/reader/spirv/parser_impl.h
+++ b/src/reader/spirv/parser_impl.h
@@ -303,6 +303,13 @@
   /// Converts a specific SPIR-V type to a Tint type. Pointer case
   ast::type::Type* ConvertType(const spvtools::opt::analysis::Pointer* ptr_ty);
 
+  /// Applies SPIR-V decorations to the given array or runtime-array type.
+  /// @param spv_type the SPIR-V aray or runtime-array type.
+  /// @param ast_type non-null; the AST type to apply decorations to
+  /// @returns true on success.
+  bool ApplyArrayDecorations(const spvtools::opt::analysis::Type* spv_type,
+                             ast::type::ArrayType* ast_type);
+
   // The SPIR-V binary we're parsing
   std::vector<uint32_t> spv_binary_;
 
diff --git a/src/reader/spirv/parser_impl_convert_type_test.cc b/src/reader/spirv/parser_impl_convert_type_test.cc
index 84e80db..8ee2f1d 100644
--- a/src/reader/spirv/parser_impl_convert_type_test.cc
+++ b/src/reader/spirv/parser_impl_convert_type_test.cc
@@ -342,13 +342,74 @@
   auto* arr_type = type->AsArray();
   EXPECT_TRUE(arr_type->IsRuntimeArray());
   ASSERT_NE(arr_type, nullptr);
-  ASSERT_EQ(arr_type->size(), 0u);
+  EXPECT_EQ(arr_type->size(), 0u);
+  EXPECT_EQ(arr_type->array_stride(), 0u);
+  EXPECT_FALSE(arr_type->has_array_stride());
   auto* elem_type = arr_type->type();
   ASSERT_NE(elem_type, nullptr);
   EXPECT_TRUE(elem_type->IsU32());
   EXPECT_TRUE(p->error().empty());
 }
 
+TEST_F(SpvParserTest, ConvertType_RuntimeArray_InvalidDecoration) {
+  auto* p = parser(test::Assemble(R"(
+    OpDecorate %10 Block
+    %uint = OpTypeInt 32 0
+    %10 = OpTypeRuntimeArray %uint
+  )"));
+  EXPECT_TRUE(p->BuildInternalModule());
+  auto* type = p->ConvertType(10);
+  EXPECT_EQ(type, nullptr);
+  EXPECT_THAT(
+      p->error(),
+      Eq("invalid array type ID 10: unknown decoration 2 with 1 total words"));
+}
+
+TEST_F(SpvParserTest, ConvertType_RuntimeArray_ArrayStride_Valid) {
+  auto* p = parser(test::Assemble(R"(
+    OpDecorate %10 ArrayStride 64
+    %uint = OpTypeInt 32 0
+    %10 = OpTypeRuntimeArray %uint
+  )"));
+  EXPECT_TRUE(p->BuildInternalModule());
+  auto* type = p->ConvertType(10);
+  ASSERT_NE(type, nullptr);
+  auto* arr_type = type->AsArray();
+  EXPECT_TRUE(arr_type->IsRuntimeArray());
+  ASSERT_NE(arr_type, nullptr);
+  EXPECT_EQ(arr_type->array_stride(), 64u);
+  EXPECT_TRUE(arr_type->has_array_stride());
+  EXPECT_TRUE(p->error().empty());
+}
+
+TEST_F(SpvParserTest, ConvertType_RuntimeArray_ArrayStride_ZeroIsError) {
+  auto* p = parser(test::Assemble(R"(
+    OpDecorate %10 ArrayStride 0
+    %uint = OpTypeInt 32 0
+    %10 = OpTypeRuntimeArray %uint
+  )"));
+  EXPECT_TRUE(p->BuildInternalModule());
+  auto* type = p->ConvertType(10);
+  EXPECT_EQ(type, nullptr);
+  EXPECT_THAT(p->error(),
+              Eq("invalid array type ID 10: ArrayStride can't be 0"));
+}
+
+TEST_F(SpvParserTest,
+       ConvertType_RuntimeArray_ArrayStride_SpecifiedTwiceIsError) {
+  auto* p = parser(test::Assemble(R"(
+    OpDecorate %10 ArrayStride 64
+    OpDecorate %10 ArrayStride 64
+    %uint = OpTypeInt 32 0
+    %10 = OpTypeRuntimeArray %uint
+  )"));
+  EXPECT_TRUE(p->BuildInternalModule());
+  auto* type = p->ConvertType(10);
+  EXPECT_EQ(type, nullptr);
+  EXPECT_THAT(p->error(),
+              Eq("invalid array type ID 10: multiple ArrayStride decorations"));
+}
+
 TEST_F(SpvParserTest, ConvertType_Array) {
   auto* p = parser(test::Assemble(R"(
     %uint = OpTypeInt 32 0
@@ -363,7 +424,9 @@
   auto* arr_type = type->AsArray();
   EXPECT_FALSE(arr_type->IsRuntimeArray());
   ASSERT_NE(arr_type, nullptr);
-  ASSERT_EQ(arr_type->size(), 42u);
+  EXPECT_EQ(arr_type->size(), 42u);
+  EXPECT_EQ(arr_type->array_stride(), 0u);
+  EXPECT_FALSE(arr_type->has_array_stride());
   auto* elem_type = arr_type->type();
   ASSERT_NE(elem_type, nullptr);
   EXPECT_TRUE(elem_type->IsU32());
@@ -419,6 +482,71 @@
   EXPECT_THAT(p->error(), Eq("unhandled integer width: 64"));
 }
 
+TEST_F(SpvParserTest, ConvertType_Array_InvalidDecoration) {
+  auto* p = parser(test::Assemble(R"(
+    OpDecorate %10 Block
+    %uint = OpTypeInt 32 0
+    %uint_5 = OpConstant %uint 5
+    %10 = OpTypeArray %uint %uint_5
+  )"));
+  EXPECT_TRUE(p->BuildInternalModule());
+  auto* type = p->ConvertType(10);
+  EXPECT_EQ(type, nullptr);
+  EXPECT_THAT(
+      p->error(),
+      Eq("invalid array type ID 10: unknown decoration 2 with 1 total words"));
+}
+
+TEST_F(SpvParserTest, ConvertType_ArrayStride_Valid) {
+  auto* p = parser(test::Assemble(R"(
+    OpDecorate %10 ArrayStride 8
+    %uint = OpTypeInt 32 0
+    %uint_5 = OpConstant %uint 5
+    %10 = OpTypeArray %uint %uint_5
+  )"));
+  EXPECT_TRUE(p->BuildInternalModule());
+
+  auto* type = p->ConvertType(10);
+  ASSERT_NE(type, nullptr);
+  EXPECT_TRUE(type->IsArray());
+  auto* arr_type = type->AsArray();
+  ASSERT_NE(arr_type, nullptr);
+  ASSERT_EQ(arr_type->array_stride(), 8u);
+  EXPECT_TRUE(arr_type->has_array_stride());
+  EXPECT_TRUE(p->error().empty());
+}
+
+TEST_F(SpvParserTest, ConvertType_ArrayStride_ZeroIsError) {
+  auto* p = parser(test::Assemble(R"(
+    OpDecorate %10 ArrayStride 0
+    %uint = OpTypeInt 32 0
+    %uint_5 = OpConstant %uint 5
+    %10 = OpTypeArray %uint %uint_5
+  )"));
+  EXPECT_TRUE(p->BuildInternalModule());
+
+  auto* type = p->ConvertType(10);
+  ASSERT_EQ(type, nullptr);
+  EXPECT_THAT(p->error(),
+              Eq("invalid array type ID 10: ArrayStride can't be 0"));
+}
+
+TEST_F(SpvParserTest, ConvertType_ArrayStride_SpecifiedTwiceIsError) {
+  auto* p = parser(test::Assemble(R"(
+    OpDecorate %10 ArrayStride 4
+    OpDecorate %10 ArrayStride 4
+    %uint = OpTypeInt 32 0
+    %uint_5 = OpConstant %uint 5
+    %10 = OpTypeArray %uint %uint_5
+  )"));
+  EXPECT_TRUE(p->BuildInternalModule());
+
+  auto* type = p->ConvertType(10);
+  ASSERT_EQ(type, nullptr);
+  EXPECT_THAT(p->error(),
+              Eq("invalid array type ID 10: multiple ArrayStride decorations"));
+}
+
 TEST_F(SpvParserTest, ConvertType_StructTwoMembers) {
   auto* p = parser(test::Assemble(R"(
     %uint = OpTypeInt 32 0