[HLSL] Adds diagnostics for missing/ambiguous shader entry function. (#184892)

Addresses #119260.

Author: danbrown-amd

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -13712,6 +13712,9 @@ def err_hlsl_matrix_layout_non_matrix
 def err_hlsl_matrix_layout_conflict
     : Error<"%0 and %1 attributes are not compatible">;
 
+def err_hlsl_ambiguous_entry_point : Error<
+   "ambiguous entry point definition '%0'">;
+def err_hlsl_missing_entry_point : Error<"missing entry point definition '%0'">;
 def err_hlsl_entry_shader_attr_mismatch : Error<
    "%0 attribute on entry function does not match the target profile">;
 def err_hlsl_numthreads_argument_oor : Error<"argument '%select{X|Y|Z}0' to numthreads attribute cannot exceed %1">;

clang/lib/Sema/SemaHLSL.cpp

@@ -2993,6 +2993,11 @@ void DiagnoseHLSLAvailability::HandleFunctionOrMethodRef(FunctionDecl *FD,
 
 void DiagnoseHLSLAvailability::RunOnTranslationUnit(
     const TranslationUnitDecl *TU) {
+  const TargetInfo &TargetInfo = SemaRef.getASTContext().getTargetInfo();
+  std::string &EntryName = TargetInfo.getTargetOpts().HLSLEntry;
+  bool IsLibraryShader = TargetInfo.getTriple().getEnvironment() ==
+                         llvm::Triple::EnvironmentType::Library;
+  SourceLocation EntryLoc{};
 
   // Iterate over all shader entry functions and library exports, and for those
   // that have a body (definiton), run diag scan on each, setting appropriate
@@ -3023,6 +3028,17 @@ void DiagnoseHLSLAvailability::RunOnTranslationUnit(
 
       // shader entry point
       if (HLSLShaderAttr *ShaderAttr = FD->getAttr<HLSLShaderAttr>()) {
+        if (!IsLibraryShader && FD->getName() == EntryName) {
+          if (EntryLoc.isValid()) {
+            SemaRef.Diag(FD->getLocation(),
+                         diag::err_hlsl_ambiguous_entry_point)
+                << EntryName;
+            SemaRef.Diag(EntryLoc, diag::note_previous_declaration_as)
+                << EntryName;
+            return;
+          }
+          EntryLoc = FD->getLocation();
+        }
         SetShaderStageContext(ShaderAttr->getType());
         RunOnFunction(FD);
         continue;
@@ -3046,6 +3062,12 @@ void DiagnoseHLSLAvailability::RunOnTranslationUnit(
       }
     }
   }
+
+  if (!IsLibraryShader && EntryLoc.isInvalid()) {
+    SemaRef.Diag(TU->getLocation(), diag::err_hlsl_missing_entry_point)
+        << EntryName;
+    return;
+  }
 }
 
 void DiagnoseHLSLAvailability::RunOnFunction(const FunctionDecl *FD) {

clang/test/AST/HLSL/HLSLControlFlowHint.hlsl

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-compute -ast-dump %s | FileCheck %s
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -ast-dump %s | FileCheck %s
 
 // CHECK: FunctionDecl {{.*}} used branch 'int (int)'
 // CHECK: AttributedStmt

clang/test/AST/HLSL/matrix-alias.hlsl

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -ast-dump -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -hlsl-entry entry -ast-dump -o - %s | FileCheck %s
 
 // Test that matrix aliases are set up properly for HLSL
 
@@ -20,8 +20,8 @@
 // Make sure we got a using directive at the end.
 // CHECK: UsingDirectiveDecl 0x{{[0-9a-fA-F]+}} <<invalid sloc>> <invalid sloc> Namespace 0x{{[0-9a-fA-F]+}} 'hlsl'
 
-[numthreads(1,1,1)]
-int entry() {
+[shader("compute"), numthreads(1,1,1)]
+void entry() {
   // Verify that the alias is generated inside the hlsl namespace.
   hlsl::matrix<float, 2, 2> Mat2x2f;
 
@@ -45,5 +45,5 @@ int entry() {
 
   // CHECK: DeclStmt 0x{{[0-9a-fA-F]+}} <line:44:3, col:21>
   // CHECK-NEXT: VarDecl 0x{{[0-9a-fA-F]+}} <col:3, col:12> col:12 ImpMat4x4 'matrix<>':'matrix<float, 4, 4>'
-  return 1;
+  return;
 }

clang/test/AST/HLSL/matrix-constructors.hlsl

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -ast-dump -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -hlsl-entry ok -ast-dump -o - %s | FileCheck %s
 
 
 typedef float float2x1 __attribute__((matrix_type(2,1)));
@@ -8,6 +8,7 @@ typedef float float4x4 __attribute__((matrix_type(4,4)));
 typedef float float2 __attribute__((ext_vector_type(2)));
 typedef float float4 __attribute__((ext_vector_type(4)));
 
+[shader("compute")]
 [numthreads(1,1,1)]
 void ok() {
 // CHECK: VarDecl 0x{{[0-9a-fA-F]+}} <col:{{[0-9]+}}, col:{{[0-9]+}}> col:{{[0-9]+}} A 'float2x3':'matrix<float, 2, 3>' cinit

clang/test/AST/HLSL/matrix-elementexpr-tree-transform.hlsl

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -std=hlsl202x \
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-library -x hlsl -std=hlsl202x \
 // RUN:   -finclude-default-header -ast-dump -ast-dump-filter=get00 %s | FileCheck %s
 
 template <typename T>

clang/test/AST/HLSL/matrix-general-initializer.hlsl

@@ -1,10 +1,10 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -ast-dump -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -hlsl-entry ok -ast-dump -o - %s | FileCheck %s
 
 typedef float float4x2 __attribute__((matrix_type(4,2)));
 typedef float float2x2 __attribute__((matrix_type(2,2)));
 typedef int int4x4 __attribute__((matrix_type(4,4)));
 
-
+[shader("compute")]
 [numthreads(1,1,1)]
 void ok() {
 
@@ -257,4 +257,4 @@ float2x2 m2 = {0.xxxx};
 // CHECK-NEXT: IntegerLiteral 0x{{[0-9a-fA-F]+}} <col:{{[0-9]+}}> 'int' 1
 int4x4 m3 = {m2, m2, m2, m2};
 
-}
+}

clang/test/AST/HLSL/matrix-member-access-scalar.hlsl

@@ -1,7 +1,8 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -ast-dump -o - %s | FileCheck %s 
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -hlsl-entry ok -ast-dump -o - %s | FileCheck %s 
 
 typedef float float3x3 __attribute__((matrix_type(3,3)));
 
+[shader("compute")]
 [numthreads(1,1,1)]
 void ok() {
     float3x3 A;

clang/test/AST/HLSL/matrix-member-access-swizzle.hlsl

@@ -1,11 +1,12 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -ast-dump -o - %s | FileCheck %s 
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -x hlsl -hlsl-entry ok -ast-dump -o - %s | FileCheck %s 
 
 typedef float float3x3 __attribute__((matrix_type(3,3)));
 typedef float float4x4 __attribute__((matrix_type(4,4)));
 typedef float float2 __attribute__((ext_vector_type(2)));
 typedef float float3 __attribute__((ext_vector_type(3)));
 typedef float float4 __attribute__((ext_vector_type(4)));
 
+[shader("compute")]
 [numthreads(1,1,1)]
 void ok() {
     float3x3 A;

clang/test/AST/HLSL/resources-in-structs-errors.hlsl

@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -verify %s
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-library -verify %s
 
 struct A {
   RWBuffer<float> Buf;