SjLj EH introduces can introduce an additional edge to a landing pad and pad

normalization needs to take this into account.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94046 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach 2010-01-20 23:03:55 +00:00
parent 10d33a4937
commit 8d77cc8c5f

View File

@ -21,6 +21,7 @@
#include "llvm/IntrinsicInst.h"
#include "llvm/Module.h"
#include "llvm/Pass.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/PromoteMemToReg.h"
@ -114,6 +115,9 @@ FunctionPass *llvm::createDwarfEHPass(const TargetLowering *tli, bool fast) {
bool DwarfEHPrepare::NormalizeLandingPads() {
bool Changed = false;
const MCAsmInfo *MAI = TLI->getTargetMachine().getMCAsmInfo();
bool usingSjLjEH = MAI->getExceptionHandlingType() == ExceptionHandling::SjLj;
for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
TerminatorInst *TI = I->getTerminator();
if (!isa<InvokeInst>(TI))
@ -125,9 +129,18 @@ bool DwarfEHPrepare::NormalizeLandingPads() {
// Check that only invoke unwind edges end at the landing pad.
bool OnlyUnwoundTo = true;
bool SwitchOK = usingSjLjEH;
for (pred_iterator PI = pred_begin(LPad), PE = pred_end(LPad);
PI != PE; ++PI) {
TerminatorInst *PT = (*PI)->getTerminator();
// The SjLj dispatch block uses a switch instruction. This is effectively
// an unwind edge, so we can disregard it here. There will only ever
// be one dispatch, however, so if there are multiple switches, one
// of them truly is a normal edge, not an unwind edge.
if (SwitchOK && isa<SwitchInst>(PT)) {
SwitchOK = false;
continue;
}
if (!isa<InvokeInst>(PT) || LPad == PT->getSuccessor(0)) {
OnlyUnwoundTo = false;
break;