[clang] [HLSL] Fix placement of `const` for resource operator[] (PR #116698)

[Justin Bogner via cfe-commits]

https://github.com/bogner created https://github.com/llvm/llvm-project/pull/116698

We had an incorrect AST here - We want `const T &`, not `T &const`.

>From 7b8f568725dc3828c6ce1fdfac2151de9359ae2d Mon Sep 17 00:00:00 2001
From: Justin Bogner <mail at justinbogner.com>
Date: Wed, 13 Nov 2024 13:56:28 -0800
Subject: [PATCH] [HLSL] Fix placement of `const` for resource operator[]

We had an incorrect AST here - We want `const T &`, not `T &const`.
---
 clang/lib/Sema/HLSLExternalSemaSource.cpp                      | 2 +-
 clang/test/AST/HLSL/AppendStructuredBuffer-AST.hlsl            | 2 +-
 clang/test/AST/HLSL/ConsumeStructuredBuffer-AST.hlsl           | 2 +-
 clang/test/AST/HLSL/RWBuffer-AST.hlsl                          | 2 +-
 clang/test/AST/HLSL/RWStructuredBuffer-AST.hlsl                | 2 +-
 clang/test/AST/HLSL/RasterizerOrderedStructuredBuffer-AST.hlsl | 2 +-
 clang/test/AST/HLSL/StructuredBuffer-AST.hlsl                  | 2 +-
 7 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/clang/lib/Sema/HLSLExternalSemaSource.cpp b/clang/lib/Sema/HLSLExternalSemaSource.cpp
index cac15b974a276e..09f149a2cc1d50 100644
--- a/clang/lib/Sema/HLSLExternalSemaSource.cpp
+++ b/clang/lib/Sema/HLSLExternalSemaSource.cpp
@@ -212,11 +212,11 @@ struct BuiltinTypeDeclBuilder {
 
     // Subscript operators return references to elements, const makes the
     // reference and method const so that the underlying data is not mutable.
-    ReturnTy = AST.getLValueReferenceType(ReturnTy);
     if (IsConst) {
       ExtInfo.TypeQuals.addConst();
       ReturnTy.addConst();
     }
+    ReturnTy = AST.getLValueReferenceType(ReturnTy);
 
     QualType MethodTy =
         AST.getFunctionType(ReturnTy, {AST.UnsignedIntTy}, ExtInfo);
diff --git a/clang/test/AST/HLSL/AppendStructuredBuffer-AST.hlsl b/clang/test/AST/HLSL/AppendStructuredBuffer-AST.hlsl
index 5a13ca7735f999..cc631a2deb2ba0 100644
--- a/clang/test/AST/HLSL/AppendStructuredBuffer-AST.hlsl
+++ b/clang/test/AST/HLSL/AppendStructuredBuffer-AST.hlsl
@@ -36,7 +36,7 @@ AppendStructuredBuffer<int> Buffer;
 // CHECK-SAME{LITERAL}: [[hlsl::contained_type(element_type)]]
 // CHECK-NEXT: HLSLResourceAttr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> Implicit RawBuffer
 
-// CHECK-NOT: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'element_type &const (unsigned int) const'
+// CHECK-NOT: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'const element_type &(unsigned int) const'
 // CHECK-NOT: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'element_type &(unsigned int)'
 
 // CHECK: ClassTemplateSpecializationDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> class AppendStructuredBuffer definition
diff --git a/clang/test/AST/HLSL/ConsumeStructuredBuffer-AST.hlsl b/clang/test/AST/HLSL/ConsumeStructuredBuffer-AST.hlsl
index b75f3fcb959cfc..ba8958cb350440 100644
--- a/clang/test/AST/HLSL/ConsumeStructuredBuffer-AST.hlsl
+++ b/clang/test/AST/HLSL/ConsumeStructuredBuffer-AST.hlsl
@@ -36,7 +36,7 @@ ConsumeStructuredBuffer<int> Buffer;
 // CHECK-SAME{LITERAL}: [[hlsl::contained_type(element_type)]]
 // CHECK-NEXT: HLSLResourceAttr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> Implicit RawBuffer
 
-// CHECK-NOT: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'element_type &const (unsigned int) const'
+// CHECK-NOT: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'const element_type &(unsigned int) const'
 // CHECK-NOT: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'element_type &(unsigned int)'
 
 // CHECK: ClassTemplateSpecializationDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> class ConsumeStructuredBuffer definition
diff --git a/clang/test/AST/HLSL/RWBuffer-AST.hlsl b/clang/test/AST/HLSL/RWBuffer-AST.hlsl
index ebddd72ddb1e0e..87462bdca5ce76 100644
--- a/clang/test/AST/HLSL/RWBuffer-AST.hlsl
+++ b/clang/test/AST/HLSL/RWBuffer-AST.hlsl
@@ -34,7 +34,7 @@ RWBuffer<float> Buffer;
 // CHECK-SAME{LITERAL}: [[hlsl::contained_type(element_type)]]
 // CHECK-NEXT: HLSLResourceAttr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> Implicit TypedBuffer
 
-// CHECK: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'element_type &const (unsigned int) const'
+// CHECK: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'const element_type &(unsigned int) const'
 // CHECK-NEXT: ParmVarDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> Idx 'unsigned int'
 // CHECK-NEXT: CompoundStmt 0x{{[0-9A-Fa-f]+}} <<invalid sloc>>
 // CHECK-NEXT: ReturnStmt 0x{{[0-9A-Fa-f]+}} <<invalid sloc>>
diff --git a/clang/test/AST/HLSL/RWStructuredBuffer-AST.hlsl b/clang/test/AST/HLSL/RWStructuredBuffer-AST.hlsl
index 4a1e1d7570e5e9..76a5689ff1172e 100644
--- a/clang/test/AST/HLSL/RWStructuredBuffer-AST.hlsl
+++ b/clang/test/AST/HLSL/RWStructuredBuffer-AST.hlsl
@@ -36,7 +36,7 @@ RWStructuredBuffer<int> Buffer;
 // CHECK-SAME{LITERAL}: [[hlsl::contained_type(element_type)]]
 // CHECK-NEXT: HLSLResourceAttr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> Implicit RawBuffer
 
-// CHECK: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'element_type &const (unsigned int) const'
+// CHECK: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'const element_type &(unsigned int) const'
 // CHECK-NEXT: ParmVarDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> Idx 'unsigned int'
 // CHECK-NEXT: CompoundStmt 0x{{[0-9A-Fa-f]+}} <<invalid sloc>>
 // CHECK-NEXT: ReturnStmt 0x{{[0-9A-Fa-f]+}} <<invalid sloc>>
diff --git a/clang/test/AST/HLSL/RasterizerOrderedStructuredBuffer-AST.hlsl b/clang/test/AST/HLSL/RasterizerOrderedStructuredBuffer-AST.hlsl
index f334e1bb6db3fc..cfd8e49a1b5aca 100644
--- a/clang/test/AST/HLSL/RasterizerOrderedStructuredBuffer-AST.hlsl
+++ b/clang/test/AST/HLSL/RasterizerOrderedStructuredBuffer-AST.hlsl
@@ -37,7 +37,7 @@ RasterizerOrderedStructuredBuffer<int> Buffer;
 // CHECK-SAME{LITERAL}: [[hlsl::contained_type(element_type)]]
 // CHECK-NEXT: HLSLResourceAttr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> Implicit TypedBuffer
 
-// CHECK: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'element_type &const (unsigned int) const'
+// CHECK: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'const element_type &(unsigned int) const'
 // CHECK-NEXT: ParmVarDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> Idx 'unsigned int'
 // CHECK-NEXT: CompoundStmt 0x{{[0-9A-Fa-f]+}} <<invalid sloc>>
 // CHECK-NEXT: ReturnStmt 0x{{[0-9A-Fa-f]+}} <<invalid sloc>>
diff --git a/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl b/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl
index 521c3d45b20225..05aa473bc407b0 100644
--- a/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl
+++ b/clang/test/AST/HLSL/StructuredBuffer-AST.hlsl
@@ -36,7 +36,7 @@ StructuredBuffer<float> Buffer;
 // CHECK-SAME{LITERAL}: [[hlsl::contained_type(element_type)]]
 // CHECK-NEXT: HLSLResourceAttr 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> Implicit RawBuffer
 
-// CHECK: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'element_type &const (unsigned int) const'
+// CHECK: CXXMethodDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> operator[] 'const element_type &(unsigned int) const'
 // CHECK-NEXT: ParmVarDecl 0x{{[0-9A-Fa-f]+}} <<invalid sloc>> <invalid sloc> Idx 'unsigned int'
 // CHECK-NEXT: CompoundStmt 0x{{[0-9A-Fa-f]+}} <<invalid sloc>>
 // CHECK-NEXT: ReturnStmt 0x{{[0-9A-Fa-f]+}} <<invalid sloc>>