[PATCH] D150499: [AST] Initialized data after TypeSourceInfo

[Vitaly Buka via Phabricator via cfe-commits]

vitalybuka created this revision.
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There is no initialization of the data between allocation
and first getBeginLoc call.

llvm-project/clang/lib/AST/ASTContext.cpp:3022
llvm-project/clang/lib/AST/TypeLoc.cpp:222

Msan report https://reviews.llvm.org/P8306


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D150499

Files:
  clang/include/clang/AST/Type.h
  clang/include/clang/AST/TypeLoc.h
  clang/lib/AST/ASTContext.cpp


Index: clang/lib/AST/ASTContext.cpp
===================================================================
--- clang/lib/AST/ASTContext.cpp
+++ clang/lib/AST/ASTContext.cpp
@@ -3019,7 +3019,7 @@
 
   auto *TInfo =
     (TypeSourceInfo*)BumpAlloc.Allocate(sizeof(TypeSourceInfo) + DataSize, 8);
-  new (TInfo) TypeSourceInfo(T);
+  new (TInfo) TypeSourceInfo(T, DataSize);
   return TInfo;
 }
 
Index: clang/include/clang/AST/TypeLoc.h
===================================================================
--- clang/include/clang/AST/TypeLoc.h
+++ clang/include/clang/AST/TypeLoc.h
@@ -240,6 +240,11 @@
   static SourceRange getLocalSourceRangeImpl(TypeLoc TL);
 };
 
+inline TypeSourceInfo::TypeSourceInfo(QualType ty, size_t DataSize) : Ty(ty) {
+  // Init data attached to the object. See getTypeLoc.
+  memset(this + 1, 255, DataSize);
+}
+
 /// Return the TypeLoc for a type source info.
 inline TypeLoc TypeSourceInfo::getTypeLoc() const {
   // TODO: is this alignment already sufficient?
Index: clang/include/clang/AST/Type.h
===================================================================
--- clang/include/clang/AST/Type.h
+++ clang/include/clang/AST/Type.h
@@ -6640,7 +6640,7 @@
 
   QualType Ty;
 
-  TypeSourceInfo(QualType ty) : Ty(ty) {}
+  TypeSourceInfo(QualType ty, size_t DataSize); // implemented in TypeLoc.h
 
 public:
   /// Return the type wrapped by this type source info.


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