[dawn][opengl] Pass remapped entry point name to Tint

Have Dawn tell Tint's renamer what entry point name to use when
renaming entry points, instead of reflecting it back from Tint to
Dawn.

This is a prerequisite for moving the Renamer into the backends
completely.

Bug: 375192379
Change-Id: Ie7055d49a15de73cd7dd9dbe97c16a5ae2f48d36
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/218141
Commit-Queue: James Price <[email protected]>
Reviewed-by: dan sinclair <[email protected]>

src/dawn/native/opengl/ShaderModuleGL.cpp

@@ -502,14 +502,16 @@ ResultOrError<GLuint> ShaderModule::CompileShader(
     DAWN_TRY_LOAD_OR_RUN(
         compilationResult, GetDevice(), std::move(req), GLSLCompilation::FromBlob,
         [](GLSLCompilationRequest r) -> ResultOrError<GLSLCompilation> {
+            constexpr char kRemappedEntryPointName[] = "dawn_entry_point";
             tint::ast::transform::Manager transformManager;
             tint::ast::transform::DataMap transformInputs;
 
             transformManager.Add<tint::ast::transform::SingleEntryPoint>();
             transformInputs.Add<tint::ast::transform::SingleEntryPoint::Config>(r.entryPointName);
 
             {
-                tint::ast::transform::Renamer::Remappings assignedRenamings = {};
+                tint::ast::transform::Renamer::Remappings assignedRenamings = {
+                    {r.entryPointName, kRemappedEntryPointName}};
 
                 // Give explicit renaming mappings for interstage variables
                 // Because GLSL requires interstage IO names to match.
@@ -548,35 +550,18 @@ ResultOrError<GLuint> ShaderModule::CompileShader(
             DAWN_TRY_ASSIGN(program, RunTransforms(&transformManager, r.inputProgram,
                                                    transformInputs, &transformOutputs, nullptr));
 
-            // TODO(dawn:2180): refactor out.
-            // Get the entry point name after the renamer pass.
-            // In the case of the entry-point name being a reserved GLSL keyword
-            // (including `main`) the entry-point would have been renamed
-            // regardless of the `disableSymbolRenaming` flag. Always check the
-            // rename map, and if the name was changed, get the new one.
-            auto* data = transformOutputs.Get<tint::ast::transform::Renamer::Data>();
-            DAWN_ASSERT(data != nullptr);
-            auto it = data->remappings.find(r.entryPointName.data());
-            std::string remappedEntryPoint;
-            if (it != data->remappings.end()) {
-                remappedEntryPoint = it->second;
-            } else {
-                remappedEntryPoint = r.entryPointName;
-            }
-            DAWN_ASSERT(remappedEntryPoint != "");
-
             if (r.stage == SingleShaderStage::Compute) {
                 // Validate workgroup size after program runs transforms.
                 Extent3D _;
                 DAWN_TRY_ASSIGN(_, ValidateComputeStageWorkgroupSize(
-                                       program, remappedEntryPoint.c_str(), r.limits));
+                                       program, kRemappedEntryPointName, r.limits));
             }
 
             // Intentionally assign entry point to empty to avoid a redundant 'SingleEntryPoint'
             // transform in Tint.
             // TODO(crbug.com/356424898): In the long run, we want to move SingleEntryPoint to Tint,
             // but that has interactions with SubstituteOverrides which need to be handled first.
-            remappedEntryPoint = "";
+            const std::string remappedEntryPoint = "";
 
             // Convert the AST program to an IR module.
             auto ir = tint::wgsl::reader::ProgramToLoweredIR(program);