[msan] Make sure that report callbacks do not get merged.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168873 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evgeniy Stepanov 2012-11-29 12:30:18 +00:00
parent 6bb2b5d76e
commit f62b4e3ee3

View File

@ -183,6 +183,8 @@ private:
MDNode *ColdCallWeights; MDNode *ColdCallWeights;
/// \brief The blacklist. /// \brief The blacklist.
OwningPtr<BlackList> BL; OwningPtr<BlackList> BL;
/// \brief An empty volatile inline asm that prevents callback merge.
InlineAsm *EmptyAsm;
friend class MemorySanitizerVisitor; friend class MemorySanitizerVisitor;
friend class VarArgAMD64Helper; friend class VarArgAMD64Helper;
@ -295,6 +297,11 @@ bool MemorySanitizer::doInitialization(Module &M) {
OriginTLS = new GlobalVariable( OriginTLS = new GlobalVariable(
M, IRB.getInt32Ty(), false, GlobalVariable::ExternalLinkage, 0, M, IRB.getInt32Ty(), false, GlobalVariable::ExternalLinkage, 0,
"__msan_origin_tls", 0, GlobalVariable::GeneralDynamicTLSModel); "__msan_origin_tls", 0, GlobalVariable::GeneralDynamicTLSModel);
// We insert an empty inline asm after __msan_report* to avoid callback merge.
EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
StringRef(""), StringRef(""),
/*hasSideEffects=*/true);
return true; return true;
} }
@ -391,6 +398,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
} }
CallInst *Call = IRB.CreateCall(MS.WarningFn); CallInst *Call = IRB.CreateCall(MS.WarningFn);
Call->setDebugLoc(OrigIns->getDebugLoc()); Call->setDebugLoc(OrigIns->getDebugLoc());
IRB.CreateCall(MS.EmptyAsm);
DEBUG(dbgs() << " CHECK: " << *Cmp << "\n"); DEBUG(dbgs() << " CHECK: " << *Cmp << "\n");
} }
DEBUG(dbgs() << "DONE:\n" << F); DEBUG(dbgs() << "DONE:\n" << F);