tint::transform::VertexPulling: require SingleEntryPoint

This change the vertex pulling transform to look for the single vertex
entry point in the module, instead of taking the entry point name in the
config. This is necessary because the renamer needs to run before
VertexPulling so that builtins like min() don't end up referring to the
input WGSL. Putting the renamer before VertexPulling makes the config
entry point name no longer match.

Bug: dawn:1583
Change-Id: I4c96eb83518e0d6fe8ce23b37e238f4a890eeb2f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/107080
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>

src/dawn/native/TintUtils.cpp

@@ -154,10 +154,8 @@ tint::transform::MultiplanarExternalTexture::BindingsMap BuildExternalTextureTra
 
 tint::transform::VertexPulling::Config BuildVertexPullingTransformConfig(
     const RenderPipelineBase& renderPipeline,
-    const std::string_view& entryPoint,
     BindGroupIndex pullingBufferBindingSet) {
     tint::transform::VertexPulling::Config cfg;
-    cfg.entry_point_name = entryPoint;
     cfg.pulling_group = static_cast<uint32_t>(pullingBufferBindingSet);
 
     cfg.vertex_state.resize(renderPipeline.GetVertexBufferCount());

src/dawn/native/TintUtils.h

@@ -45,7 +45,6 @@ tint::transform::MultiplanarExternalTexture::BindingsMap BuildExternalTextureTra
 
 tint::transform::VertexPulling::Config BuildVertexPullingTransformConfig(
     const RenderPipelineBase& renderPipeline,
-    const std::string_view& entryPoint,
     BindGroupIndex pullingBufferBindingSet);
 
 tint::transform::SubstituteOverride::Config BuildSubstituteOverridesTransformConfig(

src/dawn/native/metal/ShaderModuleMTL.mm

@@ -141,8 +141,8 @@ ResultOrError<CacheResult<MslCompilation>> TranslateToMSL(
     std::optional<tint::transform::VertexPulling::Config> vertexPullingTransformConfig;
     if (stage == SingleShaderStage::Vertex &&
         device->IsToggleEnabled(Toggle::MetalEnableVertexPulling)) {
-        vertexPullingTransformConfig = BuildVertexPullingTransformConfig(
+        vertexPullingTransformConfig =
-            *renderPipeline, programmableStage.entryPoint.c_str(), kPullingBufferBindingSet);
+            BuildVertexPullingTransformConfig(*renderPipeline, kPullingBufferBindingSet);
 
         for (VertexBufferSlot slot : IterateBitSet(renderPipeline->GetVertexBufferSlotsUsed())) {
             uint32_t metalIndex = renderPipeline->GetMtlVertexBufferIndex(slot);

src/tint/transform/vertex_pulling.cc

@@ -882,8 +882,18 @@ void VertexPulling::Run(CloneContext& ctx, const DataMap& inputs, DataMap&) cons
     }
 
     // Find entry point
-    auto* func = ctx.src->AST().Functions().Find(ctx.src->Symbols().Get(cfg.entry_point_name),
+    const ast::Function* func = nullptr;
-                                                 ast::PipelineStage::kVertex);
+    for (auto* fn : ctx.src->AST().Functions()) {
+        if (fn->PipelineStage() == ast::PipelineStage::kVertex) {
+            if (func != nullptr) {
+                ctx.dst->Diagnostics().add_error(
+                    diag::System::Transform,
+                    "VertexPulling found more than one vertex entry point");
+                return;
+            }
+            func = fn;
+        }
+    }
     if (func == nullptr) {
         ctx.dst->Diagnostics().add_error(diag::System::Transform,
                                          "Vertex stage entry point not found");

src/tint/transform/vertex_pulling.h

@@ -135,6 +135,8 @@ using VertexStateDescriptor = std::vector<VertexBufferLayoutDescriptor>;
 /// code, but these are types that the data may arrive as. We need to convert
 /// these smaller types into the base types such as `f32` and `u32` for the
 /// shader to use.
+///
+/// The SingleEntryPoint transform must have run before VertexPulling.
 class VertexPulling final : public Castable<VertexPulling, Transform> {
   public:
     /// Configuration options for the transform
@@ -152,9 +154,6 @@ class VertexPulling final : public Castable<VertexPulling, Transform> {
         /// @returns this Config
         Config& operator=(const Config&);
 
-        /// The entry point to add assignments into
-        std::string entry_point_name;
-
         /// The vertex state descriptor, containing info about attributes
         VertexStateDescriptor vertex_state;
 
@@ -163,7 +162,7 @@ class VertexPulling final : public Castable<VertexPulling, Transform> {
         uint32_t pulling_group = 4u;
 
         /// Reflect the fields of this class so that it can be used by tint::ForeachField()
-        TINT_REFLECT(entry_point_name, vertex_state, pulling_group);
+        TINT_REFLECT(vertex_state, pulling_group);
     };
 
     /// Constructor

src/tint/transform/vertex_pulling_test.cc

@@ -35,18 +35,21 @@ TEST_F(VertexPullingTest, Error_NoEntryPoint) {
     EXPECT_EQ(expect, str(got));
 }
 
-TEST_F(VertexPullingTest, Error_InvalidEntryPoint) {
+TEST_F(VertexPullingTest, Error_MultipleEntryPoint) {
     auto* src = R"(
 @vertex
 fn main() -> @builtin(position) vec4<f32> {
   return vec4<f32>();
 }
+@vertex
+fn main2() -> @builtin(position) vec4<f32> {
+  return vec4<f32>();
+}
 )";
 
-    auto* expect = "error: Vertex stage entry point not found";
+    auto* expect = "error: VertexPulling found more than one vertex entry point";
 
     VertexPulling::Config cfg;
-    cfg.entry_point_name = "_";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -64,7 +67,6 @@ fn main() {}
     auto* expect = "error: Vertex stage entry point not found";
 
     VertexPulling::Config cfg;
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -87,7 +89,6 @@ fn main(@location(0) var_a : f32) -> @builtin(position) vec4<f32> {
 
     VertexPulling::Config cfg;
     cfg.vertex_state = {{{15, VertexStepMode::kVertex, {{VertexFormat::kFloat32, 0, 0}}}}};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -116,7 +117,6 @@ fn main() -> @builtin(position) vec4<f32> {
 )";
 
     VertexPulling::Config cfg;
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -153,7 +153,6 @@ fn main(@builtin(vertex_index) tint_pulling_vertex_index : u32) -> @builtin(posi
 
     VertexPulling::Config cfg;
     cfg.vertex_state = {{{4, VertexStepMode::kVertex, {{VertexFormat::kFloat32, 0, 0}}}}};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -190,7 +189,6 @@ fn main(@builtin(instance_index) tint_pulling_instance_index : u32) -> @builtin(
 
     VertexPulling::Config cfg;
     cfg.vertex_state = {{{4, VertexStepMode::kInstance, {{VertexFormat::kFloat32, 0, 0}}}}};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -228,7 +226,6 @@ fn main(@builtin(vertex_index) tint_pulling_vertex_index : u32) -> @builtin(posi
     VertexPulling::Config cfg;
     cfg.vertex_state = {{{4, VertexStepMode::kVertex, {{VertexFormat::kFloat32, 0, 0}}}}};
     cfg.pulling_group = 5;
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -274,7 +271,6 @@ fn main(@builtin(vertex_index) tint_pulling_vertex_index : u32) -> @builtin(posi
 
     VertexPulling::Config cfg;
     cfg.vertex_state = {{{4, VertexStepMode::kVertex, {{VertexFormat::kFloat32, 0, 0}}}}};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -332,7 +328,6 @@ fn main(@builtin(vertex_index) custom_vertex_index : u32, @builtin(instance_inde
             {{VertexFormat::kFloat32, 0, 1}},
         },
     }};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -411,7 +406,6 @@ fn main(tint_symbol_1 : tint_symbol) -> @builtin(position) vec4<f32> {
             {{VertexFormat::kFloat32, 0, 1}},
         },
     }};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -490,7 +484,6 @@ struct Inputs {
             {{VertexFormat::kFloat32, 0, 1}},
         },
     }};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -566,7 +559,6 @@ fn main(indices : Indices) -> @builtin(position) vec4<f32> {
             {{VertexFormat::kFloat32, 0, 1}},
         },
     }};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -642,7 +634,6 @@ struct Indices {
             {{VertexFormat::kFloat32, 0, 1}},
         },
     }};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -684,7 +675,6 @@ fn main(@builtin(vertex_index) tint_pulling_vertex_index : u32) -> @builtin(posi
     cfg.vertex_state = {{{16,
                           VertexStepMode::kVertex,
                           {{VertexFormat::kFloat32, 0, 0}, {VertexFormat::kFloat32x4, 0, 1}}}}};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -738,7 +728,6 @@ fn main(@builtin(vertex_index) tint_pulling_vertex_index : u32) -> @builtin(posi
         {12, VertexStepMode::kVertex, {{VertexFormat::kFloat32x3, 0, 1}}},
         {16, VertexStepMode::kVertex, {{VertexFormat::kFloat32x4, 0, 2}}},
     }};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -788,7 +777,6 @@ fn main(@builtin(vertex_index) tint_pulling_vertex_index_1 : u32) -> @builtin(po
     cfg.vertex_state = {{{16,
                           VertexStepMode::kVertex,
                           {{VertexFormat::kFloat32, 0, 0}, {VertexFormat::kFloat32x4, 0, 1}}}}};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -933,7 +921,6 @@ fn main(@builtin(vertex_index) tint_pulling_vertex_index : u32) -> @builtin(posi
               {VertexFormat::kSint32, 64, 26},    {VertexFormat::kSint32x2, 64, 27},
               {VertexFormat::kSint32x3, 64, 28},  {VertexFormat::kSint32x4, 64, 29},
           }}}};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -1079,7 +1066,6 @@ fn main(@builtin(vertex_index) tint_pulling_vertex_index : u32) -> @builtin(posi
               {VertexFormat::kSint32, 63, 26},    {VertexFormat::kSint32x2, 63, 27},
               {VertexFormat::kSint32x3, 63, 28},  {VertexFormat::kSint32x4, 63, 29},
           }}}};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -1224,7 +1210,6 @@ fn main(@builtin(vertex_index) tint_pulling_vertex_index : u32) -> @builtin(posi
               {VertexFormat::kSint32, 64, 26},    {VertexFormat::kSint32x2, 64, 27},
               {VertexFormat::kSint32x3, 64, 28},  {VertexFormat::kSint32x4, 64, 29},
           }}}};
-    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);