[clang] 0e08374 - [clang][NFC] Add a notice to desugarForDiagnostic

[Younan Zhang via cfe-commits]

Author: Younan Zhang
Date: 2023-06-15T11:55:06+08:00
New Revision: 0e08374abb2c61a3ae5c24d5f60be3b548da9778

URL: https://github.com/llvm/llvm-project/commit/0e08374abb2c61a3ae5c24d5f60be3b548da9778
DIFF: https://github.com/llvm/llvm-project/commit/0e08374abb2c61a3ae5c24d5f60be3b548da9778.diff

LOG: [clang][NFC] Add a notice to desugarForDiagnostic

`desugarForDiagnostic` only sets ShouldAKA to true if desugaring
happens, otherwise ShouldAKA is left intact and might be uninitialized.

Victims (including me):

https://github.com/llvm/llvm-project/commit/25bf8cb3c0e3c41231289a6ff0a37b6d49b24011

https://github.com/llvm/llvm-project/commit/0e8384a0fe4f03d60cd92aba1cae074512481ca2

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D152880

Added: 
    

Modified: 
    clang/include/clang/AST/ASTDiagnostic.h
    clang/lib/AST/ASTDiagnostic.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/AST/ASTDiagnostic.h b/clang/include/clang/AST/ASTDiagnostic.h
index 4cd9097517258..ef22249828629 100644
--- a/clang/include/clang/AST/ASTDiagnostic.h
+++ b/clang/include/clang/AST/ASTDiagnostic.h
@@ -34,7 +34,8 @@ namespace clang {
       ArrayRef<intptr_t> QualTypeVals);
 
   /// Returns a desugared version of the QualType, and marks ShouldAKA as true
-  /// whenever we remove significant sugar from the type.
+  /// whenever we remove significant sugar from the type. Make sure ShouldAKA
+  /// is initialized before passing it in.
   QualType desugarForDiagnostic(ASTContext &Context, QualType QT,
                                 bool &ShouldAKA);
 }  // end namespace clang

diff  --git a/clang/lib/AST/ASTDiagnostic.cpp b/clang/lib/AST/ASTDiagnostic.cpp
index 08877aa12c024..f96a4fa3c35b0 100644
--- a/clang/lib/AST/ASTDiagnostic.cpp
+++ b/clang/lib/AST/ASTDiagnostic.cpp
@@ -25,7 +25,8 @@
 using namespace clang;
 
 // Returns a desugared version of the QualType, and marks ShouldAKA as true
-// whenever we remove significant sugar from the type.
+// whenever we remove significant sugar from the type. Make sure ShouldAKA
+// is initialized before passing it in.
 QualType clang::desugarForDiagnostic(ASTContext &Context, QualType QT,
                                      bool &ShouldAKA) {
   QualifierCollector QC;