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For SJLJ exception handling, make sure that all calls that are not marked

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as nounwind are marked with a -1 call-site value. This is necessary to, for
example, correctly process exceptions thrown from within an "unexpected"
execption handler (see SingleSource/Regression/C++/EH/expection_spec_test.cpp).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97757 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach 2010-03-04 22:07:46 +00:00
parent 436e6e7b5c
commit b58a59b3c1
1 changed files with 36 additions and 31 deletions
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67
lib/CodeGen/SjLjEHPrepare.cpp
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@ -44,7 +44,6 @@ namespace {
const Type *FunctionContextTy;
Constant *RegisterFn;
Constant *UnregisterFn;
Constant *ResumeFn;
Constant *BuiltinSetjmpFn;
Constant *FrameAddrFn;
Constant *LSDAAddrFn;
@ -67,8 +66,8 @@ namespace {
}
private:
void markInvokeCallSite(InvokeInst *II, unsigned InvokeNo,
Value *CallSite,
void insertCallSiteStore(Instruction *I, int Number, Value *CallSite);
void markInvokeCallSite(InvokeInst *II, int InvokeNo, Value *CallSite,
SwitchInst *CatchSwitch);
void splitLiveRangesLiveAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes);
bool insertSjLjEHSupport(Function &F);
@ -107,11 +106,6 @@ bool SjLjEHPass::doInitialization(Module &M) {
Type::getVoidTy(M.getContext()),
PointerType::getUnqual(FunctionContextTy),
(Type *)0);
ResumeFn =
M.getOrInsertFunction("_Unwind_SjLj_Resume",
Type::getVoidTy(M.getContext()),
VoidPtrTy,
(Type *)0);
FrameAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::frameaddress);
BuiltinSetjmpFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setjmp);
LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda);
@ -123,12 +117,22 @@ bool SjLjEHPass::doInitialization(Module &M) {
return true;
}
/// insertCallSiteStore - Insert a store of the call-site value to the
/// function context
void SjLjEHPass::insertCallSiteStore(Instruction *I, int Number,
Value *CallSite) {
ConstantInt *CallSiteNoC = ConstantInt::get(Type::getInt32Ty(I->getContext()),
Number);
// Insert a store of the call-site number
new StoreInst(CallSiteNoC, CallSite, true, I); // volatile
}
/// markInvokeCallSite - Insert code to mark the call_site for this invoke
void SjLjEHPass::markInvokeCallSite(InvokeInst *II, unsigned InvokeNo,
void SjLjEHPass::markInvokeCallSite(InvokeInst *II, int InvokeNo,
Value *CallSite,
SwitchInst *CatchSwitch) {
ConstantInt *CallSiteNoC= ConstantInt::get(Type::getInt32Ty(II->getContext()),
InvokeNo);
InvokeNo);
// The runtime comes back to the dispatcher with the call_site - 1 in
// the context. Odd, but there it is.
ConstantInt *SwitchValC = ConstantInt::get(Type::getInt32Ty(II->getContext()),
@ -145,8 +149,11 @@ void SjLjEHPass::markInvokeCallSite(InvokeInst *II, unsigned InvokeNo,
}
}
// Insert a store of the invoke num before the invoke
new StoreInst(CallSiteNoC, CallSite, true, II); // volatile
// Insert the store of the call site value
insertCallSiteStore(II, InvokeNo, CallSite);
// Record the call site value for the back end so it stays associated with
// the invoke.
CallInst::Create(CallSiteFn, CallSiteNoC, "", II);
// Add a switch case to our unwind block.
@ -272,8 +279,8 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) {
SmallVector<InvokeInst*,16> Invokes;
// Look through the terminators of the basic blocks to find invokes, returns
// and unwinds
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
// and unwinds.
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
// Remember all return instructions in case we insert an invoke into this
// function.
@ -283,6 +290,7 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) {
} else if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
Unwinds.push_back(UI);
}
}
// If we don't have any invokes or unwinds, there's nothing to do.
if (Unwinds.empty() && Invokes.empty()) return false;
@ -478,24 +486,21 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) {
for (unsigned i = 0, e = Invokes.size(); i != e; ++i)
markInvokeCallSite(Invokes[i], i+1, CallSite, DispatchSwitch);
// The front end has likely added calls to _Unwind_Resume. We need
// to find those calls and mark the call_site as -1 immediately prior.
// resume is a noreturn function, so any block that has a call to it
// should end in an 'unreachable' instruction with the call immediately
// prior. That's how we'll search.
// ??? There's got to be a better way. this is fugly.
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
if ((dyn_cast<UnreachableInst>(BB->getTerminator()))) {
BasicBlock::iterator I = BB->getTerminator();
// Check the previous instruction and see if it's a resume call
if (I == BB->begin()) continue;
if (CallInst *CI = dyn_cast<CallInst>(--I)) {
if (CI->getCalledFunction() == ResumeFn) {
Value *NegativeOne = Constant::getAllOnesValue(Int32Ty);
new StoreInst(NegativeOne, CallSite, true, I); // volatile
}
// Mark call instructions that aren't nounwind as no-action
// (call_site == -1). Skip the entry block, as prior to then, no function
// context has been created for this function and any unexpected exceptions
// thrown will go directly to the caller's context, which is what we want
// anyway, so no need to do anything here.
for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;) {
for (BasicBlock::iterator I = BB->begin(), end = BB->end(); I != end; ++I)
if (CallInst *CI = dyn_cast<CallInst>(I)) {
// Ignore calls to the EH builtins (eh.selector, eh.exception)
Constant *Callee = CI->getCalledFunction();
if (Callee != SelectorFn && Callee != ExceptionFn
&& !CI->doesNotThrow())
insertCallSiteStore(CI, -1, CallSite);
}
}
}
// Replace all unwinds with a branch to the unwind handler.
// ??? Should this ever happen with sjlj exceptions?