replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

TBAA: add isTBAAVtableAccess to MDNode so clients can call the function 

instead of having its own implementation.

The implementation of isTBAAVtableAccess is in TypeBasedAliasAnalysis.cpp
since it is related to the format of TBAA metadata.

The path for struct-path tbaa will be exercised by
test/Instrumentation/ThreadSanitizer/read_from_global.ll, vptr_read.ll, and
vptr_update.ll when struct-path tbaa is on by default.

llvm-svn: 190216
This commit is contained in:
Manman Ren 2013-09-06 22:47:05 +00:00
parent 5ef1c861dd
commit d8c68b1852
3 changed files with 24 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
llvm/include/llvm/IR/Metadata.h
View File

@ -161,6 +161,9 @@ public:
return V->getValueID() == MDNodeVal;
}
/// Check whether MDNode is a vtable access.
bool isTBAAVtableAccess() const;
/// Methods for metadata merging.
static MDNode *getMostGenericTBAA(MDNode *A, MDNode *B);
static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B);

19
llvm/lib/Analysis/TypeBasedAliasAnalysis.cpp
View File

@ -458,6 +458,25 @@ TypeBasedAliasAnalysis::getModRefInfo(ImmutableCallSite CS1,
return AliasAnalysis::getModRefInfo(CS1, CS2);
}
bool MDNode::isTBAAVtableAccess() const {
if (!EnableStructPathTBAA) {
if (getNumOperands() < 1) return false;
if (MDString *Tag1 = dyn_cast<MDString>(getOperand(0))) {
if (Tag1->getString() == "vtable pointer") return true;
}
return false;
}
// For struct-path aware TBAA, we use the access type of the tag.
if (getNumOperands() < 2) return false;
MDNode *Tag = cast_or_null<MDNode>(getOperand(1));
if (!Tag) return false;
if (MDString *Tag1 = dyn_cast<MDString>(Tag->getOperand(0))) {
if (Tag1->getString() == "vtable pointer") return true;
}
return false;
}
MDNode *MDNode::getMostGenericTBAA(MDNode *A, MDNode *B) {
if (!A || !B)
return NULL;

8
llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
View File

@ -240,12 +240,8 @@ bool ThreadSanitizer::doInitialization(Module &M) {
}
static bool isVtableAccess(Instruction *I) {
if (MDNode *Tag = I->getMetadata(LLVMContext::MD_tbaa)) {
if (Tag->getNumOperands() < 1) return false;
if (MDString *Tag1 = dyn_cast<MDString>(Tag->getOperand(0))) {
if (Tag1->getString() == "vtable pointer") return true;
}
}
if (MDNode *Tag = I->getMetadata(LLVMContext::MD_tbaa))
return Tag->isTBAAVtableAccess();
return false;
}