When inlining through an 'nounwind' call, mark inlined
calls 'nounwind'. It is important for correct C++
exception handling that nounwind markings do not get
lost, so this transformation is actually needed for
correctness.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45218 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/InlineFunction.cpp b/lib/Transforms/Utils/InlineFunction.cpp
index a2b834b..dba0e69 100644
--- a/lib/Transforms/Utils/InlineFunction.cpp
+++ b/lib/Transforms/Utils/InlineFunction.cpp
@@ -194,6 +194,10 @@
bool MustClearTailCallFlags =
isa<CallInst>(TheCall) && !cast<CallInst>(TheCall)->isTailCall();
+ // If the call to the callee cannot throw, set the 'nounwind' flag on any
+ // calls that we inline.
+ bool MarkNoUnwind = CS.doesNotThrow();
+
BasicBlock *OrigBB = TheCall->getParent();
Function *Caller = OrigBB->getParent();
@@ -207,7 +211,7 @@
std::vector<ReturnInst*> Returns;
ClonedCodeInfo InlinedFunctionInfo;
Function::iterator FirstNewBlock;
-
+
{ // Scope to destroy ValueMap after cloning.
DenseMap<const Value*, Value*> ValueMap;
@@ -323,15 +327,33 @@
// If we are inlining tail call instruction through a call site that isn't
// marked 'tail', we must remove the tail marker for any calls in the inlined
- // code.
- if (MustClearTailCallFlags && InlinedFunctionInfo.ContainsCalls) {
+ // code. Also, calls inlined through a 'nounwind' call site should be marked
+ // 'nounwind'.
+ if (InlinedFunctionInfo.ContainsCalls &&
+ (MustClearTailCallFlags || MarkNoUnwind)) {
for (Function::iterator BB = FirstNewBlock, E = Caller->end();
BB != E; ++BB)
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
- if (CallInst *CI = dyn_cast<CallInst>(I))
- CI->setTailCall(false);
+ if (CallInst *CI = dyn_cast<CallInst>(I)) {
+ if (MustClearTailCallFlags)
+ CI->setTailCall(false);
+ if (MarkNoUnwind)
+ CI->setDoesNotThrow();
+ }
}
+ // If we are inlining through a 'nounwind' call site then any inlined 'unwind'
+ // instructions are unreachable.
+ if (InlinedFunctionInfo.ContainsUnwinds && MarkNoUnwind)
+ for (Function::iterator BB = FirstNewBlock, E = Caller->end();
+ BB != E; ++BB) {
+ TerminatorInst *Term = BB->getTerminator();
+ if (isa<UnwindInst>(Term)) {
+ new UnreachableInst(Term);
+ BB->getInstList().erase(Term);
+ }
+ }
+
// If we are inlining for an invoke instruction, we must make sure to rewrite
// any inlined 'unwind' instructions into branches to the invoke exception
// destination, and call instructions into invoke instructions.