From b16a5d6e9b0e0c357351320afdf9a5ba5f78494a Mon Sep 17 00:00:00 2001
From: Ryan Harrison <rharrison@chromium.org>
Date: Mon, 25 Jan 2021 21:15:08 +0000
Subject: [PATCH] Exclude builtins from reflected stage variables

BUG=tint:456

Change-Id: I941b25dd5bf5e758d5fdecf379137d92d5db8556
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/38460
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: dan sinclair <dsinclair@chromium.org>
Reviewed-by: dan sinclair <dsinclair@chromium.org>
Auto-Submit: Ryan Harrison <rharrison@chromium.org>
---
 src/inspector/inspector.cc      |  5 +++++
 src/inspector/inspector_test.cc | 37 +++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/src/inspector/inspector.cc b/src/inspector/inspector.cc
index 5a3c9e8f95..ab60122e76 100644
--- a/src/inspector/inspector.cc
+++ b/src/inspector/inspector.cc
@@ -66,6 +66,10 @@ std::vector<EntryPoint> Inspector::GetEntryPoints() {
 
     for (auto* var : func->referenced_module_variables()) {
       auto name = module_.SymbolToName(var->symbol());
+      if (var->HasBuiltinDecoration()) {
+        continue;
+      }
+
       StageVariable stage_variable;
       stage_variable.name = name;
       auto* location_decoration = var->GetLocationDecoration();
@@ -82,6 +86,7 @@ std::vector<EntryPoint> Inspector::GetEntryPoints() {
         entry_point.output_variables.push_back(stage_variable);
       }
     }
+
     result.push_back(std::move(entry_point));
   }
 
diff --git a/src/inspector/inspector_test.cc b/src/inspector/inspector_test.cc
index b0792bbbea..9067461db9 100644
--- a/src/inspector/inspector_test.cc
+++ b/src/inspector/inspector_test.cc
@@ -1113,6 +1113,43 @@ TEST_F(InspectorGetEntryPointTest, MultipleEntryPointsSharedInOutVariables) {
   EXPECT_EQ(3u, result[1].output_variables[0].location_decoration);
 }
 
+TEST_F(InspectorGetEntryPointTest, BuiltInsNotStageVariables) {
+  mod->AddGlobalVariable(
+      Var("in_var", ast::StorageClass::kInput, ty.u32, nullptr,
+          ast::VariableDecorationList{
+              create<ast::BuiltinDecoration>(ast::Builtin::kPosition)}));
+  mod->AddGlobalVariable(
+      Var("out_var", ast::StorageClass::kOutput, ty.u32, nullptr,
+          ast::VariableDecorationList{create<ast::LocationDecoration>(0)}));
+  auto* func =
+      MakeInOutVariableBodyFunction("func", {{"in_var", "out_var"}}, {});
+  mod->Functions().Add(func);
+
+  auto* foo = MakeCallerBodyFunction(
+      "foo", "func",
+      ast::FunctionDecorationList{
+          create<ast::StageDecoration>(ast::PipelineStage::kVertex),
+      });
+  mod->Functions().Add(foo);
+
+  ASSERT_TRUE(td()->Determine()) << td()->error();
+
+  // TODO(dsinclair): Update to run the namer transform when available.
+
+  auto result = inspector()->GetEntryPoints();
+  ASSERT_FALSE(inspector()->has_error()) << inspector()->error();
+
+  ASSERT_EQ(1u, result.size());
+
+  ASSERT_EQ("foo", result[0].name);
+  ASSERT_EQ("foo", result[0].remapped_name);
+  EXPECT_EQ(0u, result[0].input_variables.size());
+  EXPECT_EQ(1u, result[0].output_variables.size());
+  EXPECT_TRUE(ContainsName(result[0].output_variables, "out_var"));
+  EXPECT_TRUE(result[0].output_variables[0].has_location_decoration);
+  EXPECT_EQ(0u, result[0].output_variables[0].location_decoration);
+}
+
 // TODO(rharrison): Reenable once GetRemappedNameForEntryPoint isn't a pass
 // through
 TEST_F(InspectorGetRemappedNameForEntryPointTest, DISABLED_NoFunctions) {