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author | Duncan Sands <baldrick@free.fr> | 2010-05-04 12:43:36 +0000 |
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committer | Duncan Sands <baldrick@free.fr> | 2010-05-04 12:43:36 +0000 |
commit | 203f7cb68b6c509b388d1662d8439693f75bb964 (patch) | |
tree | 682e419c5bf8666129f76bd20da9577d22fcb226 /lib/VMCore/Metadata.cpp | |
parent | 2f256f45612fe86f20d6439b917fbc3662e20f02 (diff) | |
download | llvm-203f7cb68b6c509b388d1662d8439693f75bb964.tar.gz llvm-203f7cb68b6c509b388d1662d8439693f75bb964.tar.bz2 llvm-203f7cb68b6c509b388d1662d8439693f75bb964.tar.xz |
Fix a variant of PR6112 found by thinking about it: when doing
RAUW of a global variable with a local variable in function F,
if function local metadata M in function G was using the global
then M would become function-local to both F and G, which is not
allowed. See the testcase for an example. Fixed by detecting
this situation and zapping the metadata operand when it occurs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103007 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/VMCore/Metadata.cpp')
-rw-r--r-- | lib/VMCore/Metadata.cpp | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/lib/VMCore/Metadata.cpp b/lib/VMCore/Metadata.cpp index 092fe00a53..73376f5a6b 100644 --- a/lib/VMCore/Metadata.cpp +++ b/lib/VMCore/Metadata.cpp @@ -115,14 +115,17 @@ MDNode::~MDNode() { } static const Function *getFunctionForValue(Value *V) { - assert(!isa<MDNode>(V) && "does not iterate over metadata operands"); if (!V) return NULL; - if (Instruction *I = dyn_cast<Instruction>(V)) - return I->getParent()->getParent(); - if (BasicBlock *BB = dyn_cast<BasicBlock>(V)) - return BB->getParent(); + if (Instruction *I = dyn_cast<Instruction>(V)) { + BasicBlock *BB = I->getParent(); + return BB ? BB->getParent() : 0; + } if (Argument *A = dyn_cast<Argument>(V)) return A->getParent(); + if (BasicBlock *BB = dyn_cast<BasicBlock>(V)) + return BB->getParent(); + if (MDNode *MD = dyn_cast<MDNode>(V)) + return MD->getFunction(); return NULL; } @@ -272,8 +275,19 @@ void MDNode::replaceOperand(MDNodeOperand *Op, Value *To) { // with an instruction or some other function-local object. If this is a // non-function-local MDNode, it can't point to a function-local object. // Handle this case by implicitly dropping the MDNode reference to null. - if (!isFunctionLocal() && To && isFunctionLocalValue(To)) - To = 0; + // Likewise if the MDNode is function-local but for a different function. + if (To && isFunctionLocalValue(To)) { + if (!isFunctionLocal()) + To = 0; + else { + const Function *F = getFunction(); + const Function *FV = getFunctionForValue(To); + // Metadata can be function-local without having an associated function. + // So only consider functions to have changed if non-null. + if (F && FV && F != FV) + To = 0; + } + } if (From == To) return; |