[ubsan] Minimize size of data for type_mismatch (Redo of D19667)
Summary:
This patch makes the type_mismatch static data 7 bytes smaller (and it
ends up being 16 bytes smaller due to alignment restrictions, at least
on some x86-64 environments).
It revs up the type_mismatch handler version since we're breaking binary
compatibility. I will soon post a patch for the compiler-rt side.
Reviewers: rsmith, kcc, vitalybuka, pgousseau, gbedwell
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28242
llvm-svn: 291236
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 183201c..e5e34a5 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -604,12 +604,13 @@
}
if (Checks.size() > 0) {
+ // Make sure we're not losing information. Alignment needs to be a power of
+ // 2
+ assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
llvm::Constant *StaticData[] = {
- EmitCheckSourceLocation(Loc),
- EmitCheckTypeDescriptor(Ty),
- llvm::ConstantInt::get(SizeTy, AlignVal),
- llvm::ConstantInt::get(Int8Ty, TCK)
- };
+ EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
+ llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
+ llvm::ConstantInt::get(Int8Ty, TCK)};
EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData, Ptr);
}