[asan] In llvm.asan.globals, allow entries to be non-GlobalVariable and skip over them
Looks like there are valid reasons why we need to allow bitcasts in llvm.asan.globals, see discussion at https://github.com/apple/swift-llvm/pull/133. Let's look through bitcasts when iterating over entries in the llvm.asan.globals list.
Differential Revision: https://reviews.llvm.org/D55794
llvm-svn: 349544
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index a5c64f3..769cd23 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -441,8 +441,11 @@
for (auto MDN : Globals->operands()) {
// Metadata node contains the global and the fields of "Entry".
assert(MDN->getNumOperands() == 5);
- auto *GV = mdconst::extract_or_null<GlobalVariable>(MDN->getOperand(0));
+ auto *V = mdconst::extract_or_null<Constant>(MDN->getOperand(0));
// The optimizer may optimize away a global entirely.
+ if (!V) continue;
+ auto *StrippedV = V->stripPointerCasts();
+ auto *GV = dyn_cast<GlobalVariable>(StrippedV);
if (!GV) continue;
// We can already have an entry for GV if it was merged with another
// global.