//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "dwarfehprepare"
-#include "llvm/Function.h"
-#include "llvm/Instructions.h"
-#include "llvm/IntrinsicInst.h"
-#include "llvm/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/Dominators.h"
#include "llvm/CodeGen/Passes.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
#include "llvm/MC/MCAsmInfo.h"
-#include "llvm/Support/CallSite.h"
+#include "llvm/Pass.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/SSAUpdater.h"
namespace {
class DwarfEHPrepare : public FunctionPass {
const TargetMachine *TM;
- const TargetLowering *TLI;
// RewindFunction - _Unwind_Resume or the target equivalent.
Constant *RewindFunction;
bool InsertUnwindResumeCalls(Function &Fn);
+ Value *GetExceptionObject(ResumeInst *RI);
public:
static char ID; // Pass identification, replacement for typeid.
- DwarfEHPrepare(const TargetMachine *tm) :
- FunctionPass(ID), TM(tm), TLI(TM->getTargetLowering()),
- RewindFunction(0) {
- initializeDominatorTreePass(*PassRegistry::getPassRegistry());
- }
+ DwarfEHPrepare(const TargetMachine *TM)
+ : FunctionPass(ID), TM(TM), RewindFunction(0) {
+ initializeDominatorTreeWrapperPassPass(*PassRegistry::getPassRegistry());
+ }
- virtual bool runOnFunction(Function &Fn);
+ bool runOnFunction(Function &Fn) override;
- virtual void getAnalysisUsage(AnalysisUsage &AU) const { }
+ void getAnalysisUsage(AnalysisUsage &AU) const override { }
- const char *getPassName() const {
+ const char *getPassName() const override {
return "Exception handling preparation";
}
};
char DwarfEHPrepare::ID = 0;
-FunctionPass *llvm::createDwarfEHPass(const TargetMachine *tm) {
- return new DwarfEHPrepare(tm);
+FunctionPass *llvm::createDwarfEHPass(const TargetMachine *TM) {
+ return new DwarfEHPrepare(TM);
+}
+
+/// GetExceptionObject - Return the exception object from the value passed into
+/// the 'resume' instruction (typically an aggregate). Clean up any dead
+/// instructions, including the 'resume' instruction.
+Value *DwarfEHPrepare::GetExceptionObject(ResumeInst *RI) {
+ Value *V = RI->getOperand(0);
+ Value *ExnObj = 0;
+ InsertValueInst *SelIVI = dyn_cast<InsertValueInst>(V);
+ LoadInst *SelLoad = 0;
+ InsertValueInst *ExcIVI = 0;
+ bool EraseIVIs = false;
+
+ if (SelIVI) {
+ if (SelIVI->getNumIndices() == 1 && *SelIVI->idx_begin() == 1) {
+ ExcIVI = dyn_cast<InsertValueInst>(SelIVI->getOperand(0));
+ if (ExcIVI && isa<UndefValue>(ExcIVI->getOperand(0)) &&
+ ExcIVI->getNumIndices() == 1 && *ExcIVI->idx_begin() == 0) {
+ ExnObj = ExcIVI->getOperand(1);
+ SelLoad = dyn_cast<LoadInst>(SelIVI->getOperand(1));
+ EraseIVIs = true;
+ }
+ }
+ }
+
+ if (!ExnObj)
+ ExnObj = ExtractValueInst::Create(RI->getOperand(0), 0, "exn.obj", RI);
+
+ RI->eraseFromParent();
+
+ if (EraseIVIs) {
+ if (SelIVI->getNumUses() == 0)
+ SelIVI->eraseFromParent();
+ if (ExcIVI->getNumUses() == 0)
+ ExcIVI->eraseFromParent();
+ if (SelLoad && SelLoad->getNumUses() == 0)
+ SelLoad->eraseFromParent();
+ }
+
+ return ExnObj;
}
/// InsertUnwindResumeCalls - Convert the ResumeInsts that are still present
/// into calls to the appropriate _Unwind_Resume function.
bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
- bool UsesNewEH = false;
SmallVector<ResumeInst*, 16> Resumes;
for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) {
TerminatorInst *TI = I->getTerminator();
if (ResumeInst *RI = dyn_cast<ResumeInst>(TI))
Resumes.push_back(RI);
- else if (InvokeInst *II = dyn_cast<InvokeInst>(TI))
- UsesNewEH = II->getUnwindDest()->isLandingPad();
}
if (Resumes.empty())
- return UsesNewEH;
+ return false;
// Find the rewind function if we didn't already.
+ const TargetLowering *TLI = TM->getTargetLowering();
if (!RewindFunction) {
LLVMContext &Ctx = Resumes[0]->getContext();
FunctionType *FTy = FunctionType::get(Type::getVoidTy(Ctx),
// Create the basic block where the _Unwind_Resume call will live.
LLVMContext &Ctx = Fn.getContext();
+ unsigned ResumesSize = Resumes.size();
+
+ if (ResumesSize == 1) {
+ // Instead of creating a new BB and PHI node, just append the call to
+ // _Unwind_Resume to the end of the single resume block.
+ ResumeInst *RI = Resumes.front();
+ BasicBlock *UnwindBB = RI->getParent();
+ Value *ExnObj = GetExceptionObject(RI);
+
+ // Call the _Unwind_Resume function.
+ CallInst *CI = CallInst::Create(RewindFunction, ExnObj, "", UnwindBB);
+ CI->setCallingConv(TLI->getLibcallCallingConv(RTLIB::UNWIND_RESUME));
+
+ // We never expect _Unwind_Resume to return.
+ new UnreachableInst(Ctx, UnwindBB);
+ return true;
+ }
+
BasicBlock *UnwindBB = BasicBlock::Create(Ctx, "unwind_resume", &Fn);
- PHINode *PN = PHINode::Create(Type::getInt8PtrTy(Ctx), Resumes.size(),
+ PHINode *PN = PHINode::Create(Type::getInt8PtrTy(Ctx), ResumesSize,
"exn.obj", UnwindBB);
// Extract the exception object from the ResumeInst and add it to the PHI node
for (SmallVectorImpl<ResumeInst*>::iterator
I = Resumes.begin(), E = Resumes.end(); I != E; ++I) {
ResumeInst *RI = *I;
- BranchInst::Create(UnwindBB, RI->getParent());
-
- Value *V = RI->getOperand(0);
- Instruction *ExnObj = 0;
- InsertValueInst *SelIVI = dyn_cast<InsertValueInst>(V);
- LoadInst *SelLoad = 0;
- InsertValueInst *ExcIVI = 0;
- bool EraseIVIs = false;
- if (SelIVI) {
- if (SelIVI->getNumIndices() == 1 && *SelIVI->idx_begin() == 1) {
- ExcIVI = dyn_cast<InsertValueInst>(SelIVI->getOperand(0));
- if (ExcIVI && isa<UndefValue>(ExcIVI->getOperand(0)) &&
- ExcIVI->getNumIndices() == 1 && *ExcIVI->idx_begin() == 0) {
- ExnObj = cast<Instruction>(ExcIVI->getOperand(1));
- SelLoad = dyn_cast<LoadInst>(SelIVI->getOperand(1));
- EraseIVIs = true;
- }
- }
- }
-
- if (!ExnObj)
- ExnObj = ExtractValueInst::Create(RI->getOperand(0), 0, "exn.obj", RI);
+ BasicBlock *Parent = RI->getParent();
+ BranchInst::Create(UnwindBB, Parent);
- PN->addIncoming(ExnObj, RI->getParent());
- RI->eraseFromParent();
-
- if (EraseIVIs) {
- if (SelIVI->getNumUses() == 0)
- SelIVI->eraseFromParent();
- if (ExcIVI->getNumUses() == 0)
- ExcIVI->eraseFromParent();
- if (SelLoad && SelLoad->getNumUses() == 0)
- SelLoad->eraseFromParent();
- }
+ Value *ExnObj = GetExceptionObject(RI);
+ PN->addIncoming(ExnObj, Parent);
++NumResumesLowered;
}
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