Remove HLSL override generation

This CL removes the override emission from the HLSL backend. The
override should be removed by the substitute_override transform
before making it to the backend.

Bug: tint:1155
Change-Id: I6fecf47a5f5616a81281b179853e0f00ba31011f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/101663
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/tint/writer/hlsl/generator_impl.cc

@@ -2846,7 +2846,12 @@ bool GeneratorImpl::EmitGlobalVariable(const ast::Variable* global) {
                 }
             }
         },
-        [&](const ast::Override* override) { return EmitOverride(override); },
+        [&](const ast::Override*) {
+            // Override is removed with SubstituteOverride
+            TINT_ICE(Writer, diagnostics_)
+                << "Override should have been removed by the substitute_override transform.";
+            return false;
+        },
         [&](const ast::Const*) {
             return true;  // Constants are embedded at their use
         },
@@ -4092,36 +4097,6 @@ bool GeneratorImpl::EmitLet(const ast::Let* let) {
     return true;
 }
 
-bool GeneratorImpl::EmitOverride(const ast::Override* override) {
-    auto* sem = builder_.Sem().Get(override);
-    auto* type = sem->Type();
-
-    auto override_id = sem->OverrideId();
-
-    line() << "#ifndef " << kSpecConstantPrefix << override_id.value;
-
-    if (override->constructor != nullptr) {
-        auto out = line();
-        out << "#define " << kSpecConstantPrefix << override_id.value << " ";
-        if (!EmitExpression(out, override->constructor)) {
-            return false;
-        }
-    } else {
-        line() << "#error spec constant required for constant id " << override_id.value;
-    }
-    line() << "#endif";
-    {
-        auto out = line();
-        out << "static const ";
-        if (!EmitTypeAndName(out, type, sem->StorageClass(), sem->Access(),
-                             builder_.Symbols().NameFor(override->symbol))) {
-            return false;
-        }
-        out << " = " << kSpecConstantPrefix << override_id.value << ";";
-    }
-    return true;
-}
-
 template <typename F>
 bool GeneratorImpl::CallBuiltinHelper(std::ostream& out,
                                       const ast::CallExpression* call,

src/tint/writer/hlsl/generator_impl.h

@@ -449,10 +449,6 @@ class GeneratorImpl : public TextGenerator {
     /// @param let the variable to generate
     /// @returns true if the variable was emitted
     bool EmitLet(const ast::Let* let);
-    /// Handles generating a module-scope 'override' declaration
-    /// @param override the 'override' to emit
-    /// @returns true if the variable was emitted
-    bool EmitOverride(const ast::Override* override);
     /// Emits call to a helper vector assignment function for the input assignment
     /// statement and vector type. This is used to work around FXC issues where
     /// assignments to vectors with dynamic indices cause compilation failures.

src/tint/writer/hlsl/generator_impl_function_test.cc

@@ -712,40 +712,6 @@ void main() {
 )");
 }
 
-TEST_F(HlslGeneratorImplTest_Function,
-       Emit_Attribute_EntryPoint_Compute_WithWorkgroup_OverridableConst) {
-    Override("width", ty.i32(), Construct(ty.i32(), 2_i), Id(7_u));
-    Override("height", ty.i32(), Construct(ty.i32(), 3_i), Id(8_u));
-    Override("depth", ty.i32(), Construct(ty.i32(), 4_i), Id(9_u));
-    Func("main", utils::Empty, ty.void_(), utils::Empty,
-         utils::Vector{
-             Stage(ast::PipelineStage::kCompute),
-             WorkgroupSize("width", "height", "depth"),
-         });
-
-    GeneratorImpl& gen = Build();
-
-    ASSERT_TRUE(gen.Generate()) << gen.error();
-    EXPECT_EQ(gen.result(), R"(#ifndef WGSL_SPEC_CONSTANT_7
-#define WGSL_SPEC_CONSTANT_7 2
-#endif
-static const int width = WGSL_SPEC_CONSTANT_7;
-#ifndef WGSL_SPEC_CONSTANT_8
-#define WGSL_SPEC_CONSTANT_8 3
-#endif
-static const int height = WGSL_SPEC_CONSTANT_8;
-#ifndef WGSL_SPEC_CONSTANT_9
-#define WGSL_SPEC_CONSTANT_9 4
-#endif
-static const int depth = WGSL_SPEC_CONSTANT_9;
-
-[numthreads(WGSL_SPEC_CONSTANT_7, WGSL_SPEC_CONSTANT_8, WGSL_SPEC_CONSTANT_9)]
-void main() {
-  return;
-}
-)");
-}
-
 TEST_F(HlslGeneratorImplTest_Function, Emit_Function_WithArrayParams) {
     Func("my_func",
          utils::Vector{

src/tint/writer/hlsl/generator_impl_module_constant_test.cc

@@ -242,50 +242,5 @@ TEST_F(HlslGeneratorImplTest_ModuleConstant, Emit_GlobalConst_arr_vec2_bool) {
 )");
 }
 
-TEST_F(HlslGeneratorImplTest_ModuleConstant, Emit_Override) {
-    auto* var = Override("pos", ty.f32(), Expr(3_f), Id(23_a));
-
-    GeneratorImpl& gen = Build();
-
-    ASSERT_TRUE(gen.EmitOverride(var)) << gen.error();
-    EXPECT_EQ(gen.result(), R"(#ifndef WGSL_SPEC_CONSTANT_23
-#define WGSL_SPEC_CONSTANT_23 3.0f
-#endif
-static const float pos = WGSL_SPEC_CONSTANT_23;
-)");
-}
-
-TEST_F(HlslGeneratorImplTest_ModuleConstant, Emit_Override_NoConstructor) {
-    auto* var = Override("pos", ty.f32(), Id(23_a));
-
-    GeneratorImpl& gen = Build();
-
-    ASSERT_TRUE(gen.EmitOverride(var)) << gen.error();
-    EXPECT_EQ(gen.result(), R"(#ifndef WGSL_SPEC_CONSTANT_23
-#error spec constant required for constant id 23
-#endif
-static const float pos = WGSL_SPEC_CONSTANT_23;
-)");
-}
-
-TEST_F(HlslGeneratorImplTest_ModuleConstant, Emit_Override_NoId) {
-    auto* a = Override("a", ty.f32(), Expr(3_f), Id(0_a));
-    auto* b = Override("b", ty.f32(), Expr(2_f));
-
-    GeneratorImpl& gen = Build();
-
-    ASSERT_TRUE(gen.EmitOverride(a)) << gen.error();
-    ASSERT_TRUE(gen.EmitOverride(b)) << gen.error();
-    EXPECT_EQ(gen.result(), R"(#ifndef WGSL_SPEC_CONSTANT_0
-#define WGSL_SPEC_CONSTANT_0 3.0f
-#endif
-static const float a = WGSL_SPEC_CONSTANT_0;
-#ifndef WGSL_SPEC_CONSTANT_1
-#define WGSL_SPEC_CONSTANT_1 2.0f
-#endif
-static const float b = WGSL_SPEC_CONSTANT_1;
-)");
-}
-
 }  // namespace
 }  // namespace tint::writer::hlsl