Revert "tint::transform::VertexPulling: require SingleEntryPoint"

This reverts commit 63463c2f775fadb56daad93e0e92fe9153a426fd.

Reason for revert: Breaks the kokoro build

Original change's description:
> 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>

TBR=cwallez@chromium.org,bclayton@google.com,noreply+kokoro@google.com,dawn-scoped@luci-project-accounts.iam.gserviceaccount.com

Change-Id: I26f521213db6ce80cdccad20cbaa6a1c0d37b2c2
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: dawn:1583
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/107280
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/dawn/native/TintUtils.cpp b/src/dawn/native/TintUtils.cpp
index 74f377e..a2cf5dc 100644
--- a/src/dawn/native/TintUtils.cpp
+++ b/src/dawn/native/TintUtils.cpp
@@ -154,8 +154,10 @@
 
 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());
diff --git a/src/dawn/native/TintUtils.h b/src/dawn/native/TintUtils.h
index fb73e4d..d6bea1d 100644
--- a/src/dawn/native/TintUtils.h
+++ b/src/dawn/native/TintUtils.h
@@ -45,6 +45,7 @@
 
 tint::transform::VertexPulling::Config BuildVertexPullingTransformConfig(
     const RenderPipelineBase& renderPipeline,
+    const std::string_view& entryPoint,
     BindGroupIndex pullingBufferBindingSet);
 
 tint::transform::SubstituteOverride::Config BuildSubstituteOverridesTransformConfig(
diff --git a/src/dawn/native/metal/ShaderModuleMTL.mm b/src/dawn/native/metal/ShaderModuleMTL.mm
index 8ab0628..e07cd1d 100644
--- a/src/dawn/native/metal/ShaderModuleMTL.mm
+++ b/src/dawn/native/metal/ShaderModuleMTL.mm
@@ -141,8 +141,8 @@
     std::optional<tint::transform::VertexPulling::Config> vertexPullingTransformConfig;
     if (stage == SingleShaderStage::Vertex &&
         device->IsToggleEnabled(Toggle::MetalEnableVertexPulling)) {
-        vertexPullingTransformConfig =
-            BuildVertexPullingTransformConfig(*renderPipeline, kPullingBufferBindingSet);
+        vertexPullingTransformConfig = BuildVertexPullingTransformConfig(
+            *renderPipeline, programmableStage.entryPoint.c_str(), kPullingBufferBindingSet);
 
         for (VertexBufferSlot slot : IterateBitSet(renderPipeline->GetVertexBufferSlotsUsed())) {
             uint32_t metalIndex = renderPipeline->GetMtlVertexBufferIndex(slot);
diff --git a/src/tint/transform/vertex_pulling.cc b/src/tint/transform/vertex_pulling.cc
index 00b5a06..2ec12d5 100644
--- a/src/tint/transform/vertex_pulling.cc
+++ b/src/tint/transform/vertex_pulling.cc
@@ -882,18 +882,8 @@
     }
 
     // Find entry point
-    const ast::Function* func = nullptr;
-    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;
-        }
-    }
+    auto* func = ctx.src->AST().Functions().Find(ctx.src->Symbols().Get(cfg.entry_point_name),
+                                                 ast::PipelineStage::kVertex);
     if (func == nullptr) {
         ctx.dst->Diagnostics().add_error(diag::System::Transform,
                                          "Vertex stage entry point not found");
diff --git a/src/tint/transform/vertex_pulling.h b/src/tint/transform/vertex_pulling.h
index 6dd35bc..255a49a 100644
--- a/src/tint/transform/vertex_pulling.h
+++ b/src/tint/transform/vertex_pulling.h
@@ -135,8 +135,6 @@
 /// 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
@@ -154,6 +152,9 @@
         /// @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;
 
@@ -162,7 +163,7 @@
         uint32_t pulling_group = 4u;
 
         /// Reflect the fields of this class so that it can be used by tint::ForeachField()
-        TINT_REFLECT(vertex_state, pulling_group);
+        TINT_REFLECT(entry_point_name, vertex_state, pulling_group);
     };
 
     /// Constructor
diff --git a/src/tint/transform/vertex_pulling_test.cc b/src/tint/transform/vertex_pulling_test.cc
index 7c774c5..5fb8b1c 100644
--- a/src/tint/transform/vertex_pulling_test.cc
+++ b/src/tint/transform/vertex_pulling_test.cc
@@ -35,21 +35,18 @@
     EXPECT_EQ(expect, str(got));
 }
 
-TEST_F(VertexPullingTest, Error_MultipleEntryPoint) {
+TEST_F(VertexPullingTest, Error_InvalidEntryPoint) {
     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: VertexPulling found more than one vertex entry point";
+    auto* expect = "error: Vertex stage entry point not found";
 
     VertexPulling::Config cfg;
+    cfg.entry_point_name = "_";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -67,6 +64,7 @@
     auto* expect = "error: Vertex stage entry point not found";
 
     VertexPulling::Config cfg;
+    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -89,6 +87,7 @@
 
     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);
@@ -117,6 +116,7 @@
 )";
 
     VertexPulling::Config cfg;
+    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -153,6 +153,7 @@
 
     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);
@@ -189,6 +190,7 @@
 
     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);
@@ -226,6 +228,7 @@
     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);
@@ -271,6 +274,7 @@
 
     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);
@@ -328,6 +332,7 @@
             {{VertexFormat::kFloat32, 0, 1}},
         },
     }};
+    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -406,6 +411,7 @@
             {{VertexFormat::kFloat32, 0, 1}},
         },
     }};
+    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -484,6 +490,7 @@
             {{VertexFormat::kFloat32, 0, 1}},
         },
     }};
+    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -559,6 +566,7 @@
             {{VertexFormat::kFloat32, 0, 1}},
         },
     }};
+    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -634,6 +642,7 @@
             {{VertexFormat::kFloat32, 0, 1}},
         },
     }};
+    cfg.entry_point_name = "main";
 
     DataMap data;
     data.Add<VertexPulling::Config>(cfg);
@@ -675,6 +684,7 @@
     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);
@@ -728,6 +738,7 @@
         {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);
@@ -777,6 +788,7 @@
     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);
@@ -921,6 +933,7 @@
               {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);
@@ -1066,6 +1079,7 @@
               {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);
@@ -1210,6 +1224,7 @@
               {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);