[clang] 806b0cd - [NFC][CLANG] Fix issue with dereference null return value found by Coverity static analyzer tool

[via cfe-commits]

Author: Manna, Soumi
Date: 2023-05-23T11:44:06-07:00
New Revision: 806b0cd5ab5686c1a90d4f13f33517f858fcf4e0

URL: https://github.com/llvm/llvm-project/commit/806b0cd5ab5686c1a90d4f13f33517f858fcf4e0
DIFF: https://github.com/llvm/llvm-project/commit/806b0cd5ab5686c1a90d4f13f33517f858fcf4e0.diff

LOG: [NFC][CLANG] Fix issue with dereference null return value found by Coverity static analyzer tool

Reported by Coverity static analyzer tool:

Inside "ItaniumCXXABI.cpp" file, in <unnamed>::ItaniumCXXABI::EmitLoadOfMemberFunctionPointer(clang::CodeGen::CodeGenFunction &, clang::Expr const *, clang::CodeGen::Address, llvm::Value *&, llvm::Value *, clang::MemberPointerType const *): Return value of function which returns null is dereferenced without checking.

   //returned_null: getAs returns nullptr (checked 130 out of 156 times).
   //var_assigned: Assigning: FPT = nullptr return value from getAs.
   const FunctionProtoType *FPT =
     MPT->getPointeeType()->getAs<FunctionProtoType>();
  auto *RD =
     cast<CXXRecordDecl>(MPT->getClass()->castAs<RecordType>()->getDecl());

  // Dereference null return value (NULL_RETURNS)
  //dereference: Dereferencing a pointer that might be nullptr FPT when calling arrangeCXXMethodType.
   llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(
       CGM.getTypes().arrangeCXXMethodType(RD, FPT, /*FD=*/nullptr));

This patch uses castAs instead of getAs which will assert if the type doesn't match.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D151054

Added: 
    

Modified: 
    clang/lib/CodeGen/ItaniumCXXABI.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index f4f722a1be06..668660124c74 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -580,7 +580,7 @@ CGCallee ItaniumCXXABI::EmitLoadOfMemberFunctionPointer(
   CGBuilderTy &Builder = CGF.Builder;
 
   const FunctionProtoType *FPT =
-    MPT->getPointeeType()->getAs<FunctionProtoType>();
+      MPT->getPointeeType()->castAs<FunctionProtoType>();
   auto *RD =
       cast<CXXRecordDecl>(MPT->getClass()->castAs<RecordType>()->getDecl());