commit c64ca23d94aae25c5573bb4ad354a8686fba285c
author Ben Clayton <bclayton@google.com> Wed Jun 29 00:55:36 2022 +0000
committer Dawn LUCI CQ <dawn-scoped@luci-project-accounts.iam.gserviceaccount.com> Wed Jun 29 00:55:36 2022 +0000
tree 905595bb39369bc88e85890d3beed3df14353b88
parent 03f88e6f49e41a888b729df633a0356a1a3321ec

tint: Deprecated module-scope 'let' for 'const'

Enable the parsing of 'const'.
Warn on use of module-scope 'let', and automatically replace with 'const'.

Fixed: tint:1580
Change-Id: I214aabca80686dc6b60ae21a7a57fbfb4898ea83
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/93786
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/tint/writer/hlsl/generator_impl.cc

diff --git a/src/tint/writer/hlsl/generator_impl.cc b/src/tint/writer/hlsl/generator_impl.cc
index defbb3e..fd502d1 100644
--- a/src/tint/writer/hlsl/generator_impl.cc
+++ b/src/tint/writer/hlsl/generator_impl.cc
@@ -2614,14 +2614,8 @@
 
 bool GeneratorImpl::EmitExpression(std::ostream& out, const ast::Expression* expr) {
     if (auto* sem = builder_.Sem().Get(expr)) {
-        if (auto* user = sem->As<sem::VariableUser>();
-            !user || !user->Variable()->Declaration()->Is<ast::Let>()) {
-            // Disable constant inlining if the constant expression is from a 'let' declaration.
-            // TODO(crbug.com/tint/1580): Once 'const' is implemented, 'let' will no longer resolve
-            // to a shader-creation time constant value, and this can be removed.
-            if (auto constant = sem->ConstantValue()) {
-                return EmitConstant(out, constant);
-            }
+        if (auto constant = sem->ConstantValue()) {
+            return EmitConstant(out, constant);
         }
     }
     return Switch(
@@ -2852,7 +2846,6 @@
                     return false;
             }
         },
-        [&](const ast::Let* let) { return EmitProgramConstVariable(let); },
         [&](const ast::Override* override) { return EmitOverride(override); },
         [&](const ast::Const*) {
             return true;  // Constants are embedded at their use
@@ -4057,25 +4050,6 @@
     return true;
 }
 
-bool GeneratorImpl::EmitProgramConstVariable(const ast::Let* let) {
-    auto* sem = builder_.Sem().Get(let);
-    auto* type = sem->Type();
-
-    auto out = line();
-    out << "static const ";
-    if (!EmitTypeAndName(out, type, ast::StorageClass::kNone, ast::Access::kUndefined,
-                         builder_.Symbols().NameFor(let->symbol))) {
-        return false;
-    }
-    out << " = ";
-    if (!EmitExpression(out, let->constructor)) {
-        return false;
-    }
-    out << ";";
-
-    return true;
-}
-
 bool GeneratorImpl::EmitOverride(const ast::Override* override) {
     auto* sem = builder_.Sem().Get(override);
     auto* type = sem->Type();