[clang] 7372c0d - [CLANG] Fix potential integer overflow value in getRVVTypeSize()

[via cfe-commits]

Author: Manna, Soumi
Date: 2023-06-28T19:25:53-07:00
New Revision: 7372c0d46d2185017c509eb30910b102b4f9cdaa

URL: https://github.com/llvm/llvm-project/commit/7372c0d46d2185017c509eb30910b102b4f9cdaa
DIFF: https://github.com/llvm/llvm-project/commit/7372c0d46d2185017c509eb30910b102b4f9cdaa.diff

LOG: [CLANG] Fix potential integer overflow value in getRVVTypeSize()

In getRVVTypeSize(clang::ASTContext &, clang::BuiltinType const *) potential integer overflow occurs on expression VScale->first * MinElts with type unsigned int (32 bits, unsigned) is evaluated using 32-bit arithmetic, and then used in a context that expects an expression of type uint64_t (64 bits, unsigned).

To avoid integer overflow, this patch changes the types of variables MinElts and EltSize to uint64_t from unsigned instead of the cast.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D153146

Added: 
    

Modified: 
    clang/lib/AST/ASTContext.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index dd040a3b8896f..65132b9eb44b8 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -9564,8 +9564,8 @@ static uint64_t getRVVTypeSize(ASTContext &Context, const BuiltinType *Ty) {
 
   ASTContext::BuiltinVectorTypeInfo Info = Context.getBuiltinVectorTypeInfo(Ty);
 
-  unsigned EltSize = Context.getTypeSize(Info.ElementType);
-  unsigned MinElts = Info.EC.getKnownMinValue();
+  uint64_t EltSize = Context.getTypeSize(Info.ElementType);
+  uint64_t MinElts = Info.EC.getKnownMinValue();
   return VScale->first * MinElts * EltSize;
 }