forked from OSchip/llvm-project
Cleanup. Get rid of the old SjLj EH lowering code. No functionality change.
llvm-svn: 142800
This commit is contained in:
Bill Wendling
parent
30b63c6430
commit
38f86c505c
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@ -30,17 +30,13 @@
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/IRBuilder.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/SmallPtrSet.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/Statistic.h"
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#include <set>
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using namespace llvm;
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static cl::opt<bool> DisableOldSjLjEH("disable-old-sjlj-eh", cl::Hidden,
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cl::init(true),
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cl::desc("Disable the old SjLj EH preparation pass"));
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STATISTIC(NumInvokes, "Number of invokes replaced");
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STATISTIC(NumUnwinds, "Number of unwinds replaced");
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STATISTIC(NumSpilled, "Number of registers live across unwind edges");
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namespace {
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@ -52,16 +48,12 @@ namespace {
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Constant *BuiltinSetjmpFn;
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Constant *FrameAddrFn;
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Constant *StackAddrFn;
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Constant *StackRestoreFn;
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Constant *LSDAAddrFn;
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Value *PersonalityFn;
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Constant *SelectorFn;
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Constant *ExceptionFn;
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Constant *CallSiteFn;
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Constant *DispatchSetupFn;
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Constant *FuncCtxFn;
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Value *CallSite;
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DenseMap<InvokeInst*, BasicBlock*> LPadSuccMap;
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public:
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static char ID; // Pass identification, replacement for typeid
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explicit SjLjEHPass(const TargetLowering *tli = NULL)
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@ -79,13 +71,7 @@ namespace {
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Value *setupFunctionContext(Function &F, ArrayRef<LandingPadInst*> LPads);
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void lowerIncomingArguments(Function &F);
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void lowerAcrossUnwindEdges(Function &F, ArrayRef<InvokeInst*> Invokes);
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void insertCallSiteStore(Instruction *I, int Number, Value *CallSite);
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void markInvokeCallSite(InvokeInst *II, int InvokeNo, Value *CallSite,
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SwitchInst *CatchSwitch);
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void splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes);
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void splitLandingPad(InvokeInst *II);
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bool insertSjLjEHSupport(Function &F);
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};
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} // end anonymous namespace
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@ -121,11 +107,8 @@ bool SjLjEHPass::doInitialization(Module &M) {
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(Type *)0);
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FrameAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::frameaddress);
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StackAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::stacksave);
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StackRestoreFn = Intrinsic::getDeclaration(&M, Intrinsic::stackrestore);
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BuiltinSetjmpFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setjmp);
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LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda);
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SelectorFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_selector);
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ExceptionFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_exception);
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CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite);
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DispatchSetupFn
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= Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_dispatch_setup);
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@ -145,572 +128,16 @@ void SjLjEHPass::insertCallSiteStore(Instruction *I, int Number,
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new StoreInst(CallSiteNoC, CallSite, true, I); // volatile
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}
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/// splitLandingPad - Split a landing pad. This takes considerable care because
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/// of PHIs and other nasties. The problem is that the jump table needs to jump
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/// to the landing pad block. However, the landing pad block can be jumped to
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/// only by an invoke instruction. So we clone the landingpad instruction into
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/// its own basic block, have the invoke jump to there. The landingpad
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/// instruction's basic block's successor is now the target for the jump table.
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///
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/// But because of PHI nodes, we need to create another basic block for the jump
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/// table to jump to. This is definitely a hack, because the values for the PHI
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/// nodes may not be defined on the edge from the jump table. But that's okay,
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/// because the jump table is simply a construct to mimic what is happening in
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/// the CFG. So the values are mysteriously there, even though there is no value
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/// for the PHI from the jump table's edge (hence calling this a hack).
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void SjLjEHPass::splitLandingPad(InvokeInst *II) {
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SmallVector<BasicBlock*, 2> NewBBs;
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SplitLandingPadPredecessors(II->getUnwindDest(), II->getParent(),
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".1", ".2", this, NewBBs);
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// Create an empty block so that the jump table has something to jump to
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// which doesn't have any PHI nodes.
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BasicBlock *LPad = NewBBs[0];
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BasicBlock *Succ = *succ_begin(LPad);
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BasicBlock *JumpTo = BasicBlock::Create(II->getContext(), "jt.land",
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LPad->getParent(), Succ);
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LPad->getTerminator()->eraseFromParent();
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BranchInst::Create(JumpTo, LPad);
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BranchInst::Create(Succ, JumpTo);
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LPadSuccMap[II] = JumpTo;
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for (BasicBlock::iterator I = Succ->begin(); isa<PHINode>(I); ++I) {
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PHINode *PN = cast<PHINode>(I);
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Value *Val = PN->removeIncomingValue(LPad, false);
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PN->addIncoming(Val, JumpTo);
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}
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}
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/// markInvokeCallSite - Insert code to mark the call_site for this invoke
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void SjLjEHPass::markInvokeCallSite(InvokeInst *II, int InvokeNo,
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Value *CallSite,
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SwitchInst *CatchSwitch) {
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ConstantInt *CallSiteNoC= ConstantInt::get(Type::getInt32Ty(II->getContext()),
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InvokeNo);
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// The runtime comes back to the dispatcher with the call_site - 1 in
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// the context. Odd, but there it is.
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ConstantInt *SwitchValC = ConstantInt::get(Type::getInt32Ty(II->getContext()),
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InvokeNo - 1);
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// If the unwind edge has phi nodes, split the edge.
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if (isa<PHINode>(II->getUnwindDest()->begin())) {
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// FIXME: New EH - This if-condition will be always true in the new scheme.
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if (II->getUnwindDest()->isLandingPad())
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splitLandingPad(II);
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else
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SplitCriticalEdge(II, 1, this);
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// If there are any phi nodes left, they must have a single predecessor.
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while (PHINode *PN = dyn_cast<PHINode>(II->getUnwindDest()->begin())) {
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PN->replaceAllUsesWith(PN->getIncomingValue(0));
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PN->eraseFromParent();
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}
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}
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// Insert the store of the call site value
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insertCallSiteStore(II, InvokeNo, CallSite);
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// Record the call site value for the back end so it stays associated with
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// the invoke.
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CallInst::Create(CallSiteFn, CallSiteNoC, "", II);
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// Add a switch case to our unwind block.
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if (BasicBlock *SuccBB = LPadSuccMap[II]) {
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CatchSwitch->addCase(SwitchValC, SuccBB);
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} else {
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CatchSwitch->addCase(SwitchValC, II->getUnwindDest());
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}
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// We still want this to look like an invoke so we emit the LSDA properly,
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// so we don't transform the invoke into a call here.
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}
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/// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until
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/// we reach blocks we've already seen.
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static void MarkBlocksLiveIn(BasicBlock *BB, std::set<BasicBlock*> &LiveBBs) {
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if (!LiveBBs.insert(BB).second) return; // already been here.
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static void MarkBlocksLiveIn(BasicBlock *BB,
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SmallPtrSet<BasicBlock*, 64> &LiveBBs) {
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if (!LiveBBs.insert(BB)) return; // already been here.
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for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI)
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MarkBlocksLiveIn(*PI, LiveBBs);
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}
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/// splitLiveRangesAcrossInvokes - Each value that is live across an unwind edge
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/// we spill into a stack location, guaranteeing that there is nothing live
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/// across the unwind edge. This process also splits all critical edges
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/// coming out of invoke's.
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/// FIXME: Move this function to a common utility file (Local.cpp?) so
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/// both SjLj and LowerInvoke can use it.
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void SjLjEHPass::
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splitLiveRangesAcrossInvokes(SmallVector<InvokeInst*,16> &Invokes) {
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// First step, split all critical edges from invoke instructions.
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for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
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InvokeInst *II = Invokes[i];
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SplitCriticalEdge(II, 0, this);
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// FIXME: New EH - This if-condition will be always true in the new scheme.
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if (II->getUnwindDest()->isLandingPad())
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splitLandingPad(II);
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else
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SplitCriticalEdge(II, 1, this);
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assert(!isa<PHINode>(II->getNormalDest()) &&
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!isa<PHINode>(II->getUnwindDest()) &&
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"Critical edge splitting left single entry phi nodes?");
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}
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Function *F = Invokes.back()->getParent()->getParent();
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// To avoid having to handle incoming arguments specially, we lower each arg
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// to a copy instruction in the entry block. This ensures that the argument
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// value itself cannot be live across the entry block.
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BasicBlock::iterator AfterAllocaInsertPt = F->begin()->begin();
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while (isa<AllocaInst>(AfterAllocaInsertPt) &&
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isa<ConstantInt>(cast<AllocaInst>(AfterAllocaInsertPt)->getArraySize()))
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++AfterAllocaInsertPt;
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for (Function::arg_iterator AI = F->arg_begin(), E = F->arg_end();
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AI != E; ++AI) {
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Type *Ty = AI->getType();
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// Aggregate types can't be cast, but are legal argument types, so we have
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// to handle them differently. We use an extract/insert pair as a
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// lightweight method to achieve the same goal.
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if (isa<StructType>(Ty) || isa<ArrayType>(Ty) || isa<VectorType>(Ty)) {
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Instruction *EI = ExtractValueInst::Create(AI, 0, "",AfterAllocaInsertPt);
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Instruction *NI = InsertValueInst::Create(AI, EI, 0);
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NI->insertAfter(EI);
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AI->replaceAllUsesWith(NI);
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// Set the operand of the instructions back to the AllocaInst.
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EI->setOperand(0, AI);
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NI->setOperand(0, AI);
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} else {
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// This is always a no-op cast because we're casting AI to AI->getType()
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// so src and destination types are identical. BitCast is the only
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// possibility.
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CastInst *NC = new BitCastInst(
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AI, AI->getType(), AI->getName()+".tmp", AfterAllocaInsertPt);
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AI->replaceAllUsesWith(NC);
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// Set the operand of the cast instruction back to the AllocaInst.
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// Normally it's forbidden to replace a CastInst's operand because it
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// could cause the opcode to reflect an illegal conversion. However,
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// we're replacing it here with the same value it was constructed with.
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// We do this because the above replaceAllUsesWith() clobbered the
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// operand, but we want this one to remain.
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NC->setOperand(0, AI);
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}
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}
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// Finally, scan the code looking for instructions with bad live ranges.
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for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
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for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E; ++II) {
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// Ignore obvious cases we don't have to handle. In particular, most
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// instructions either have no uses or only have a single use inside the
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// current block. Ignore them quickly.
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Instruction *Inst = II;
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if (Inst->use_empty()) continue;
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if (Inst->hasOneUse() &&
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cast<Instruction>(Inst->use_back())->getParent() == BB &&
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!isa<PHINode>(Inst->use_back())) continue;
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// If this is an alloca in the entry block, it's not a real register
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// value.
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if (AllocaInst *AI = dyn_cast<AllocaInst>(Inst))
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if (isa<ConstantInt>(AI->getArraySize()) && BB == F->begin())
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continue;
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// Avoid iterator invalidation by copying users to a temporary vector.
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SmallVector<Instruction*,16> Users;
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for (Value::use_iterator UI = Inst->use_begin(), E = Inst->use_end();
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UI != E; ++UI) {
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Instruction *User = cast<Instruction>(*UI);
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if (User->getParent() != BB || isa<PHINode>(User))
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Users.push_back(User);
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}
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// Find all of the blocks that this value is live in.
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std::set<BasicBlock*> LiveBBs;
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LiveBBs.insert(Inst->getParent());
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while (!Users.empty()) {
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Instruction *U = Users.back();
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Users.pop_back();
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if (!isa<PHINode>(U)) {
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MarkBlocksLiveIn(U->getParent(), LiveBBs);
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} else {
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// Uses for a PHI node occur in their predecessor block.
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PHINode *PN = cast<PHINode>(U);
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for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
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if (PN->getIncomingValue(i) == Inst)
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MarkBlocksLiveIn(PN->getIncomingBlock(i), LiveBBs);
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}
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}
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// Now that we know all of the blocks that this thing is live in, see if
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// it includes any of the unwind locations.
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bool NeedsSpill = false;
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for (unsigned i = 0, e = Invokes.size(); i != e; ++i) {
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BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest();
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if (UnwindBlock != BB && LiveBBs.count(UnwindBlock))
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NeedsSpill = true;
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}
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// If we decided we need a spill, do it.
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// FIXME: Spilling this way is overkill, as it forces all uses of
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// the value to be reloaded from the stack slot, even those that aren't
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// in the unwind blocks. We should be more selective.
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if (NeedsSpill) {
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++NumSpilled;
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DemoteRegToStack(*Inst, true);
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}
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}
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}
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/// CreateLandingPadLoad - Load the exception handling values and insert them
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/// into a structure.
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static Instruction *CreateLandingPadLoad(Function &F, Value *ExnAddr,
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Value *SelAddr,
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BasicBlock::iterator InsertPt) {
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Value *Exn = new LoadInst(ExnAddr, "exn", false,
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InsertPt);
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Type *Ty = Type::getInt8PtrTy(F.getContext());
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Exn = CastInst::Create(Instruction::IntToPtr, Exn, Ty, "", InsertPt);
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Value *Sel = new LoadInst(SelAddr, "sel", false, InsertPt);
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Ty = StructType::get(Exn->getType(), Sel->getType(), NULL);
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InsertValueInst *LPadVal = InsertValueInst::Create(llvm::UndefValue::get(Ty),
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Exn, 0,
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"lpad.val", InsertPt);
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return InsertValueInst::Create(LPadVal, Sel, 1, "lpad.val", InsertPt);
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}
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/// ReplaceLandingPadVal - Replace the landingpad instruction's value with a
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/// load from the stored values (via CreateLandingPadLoad). This looks through
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/// PHI nodes, and removes them if they are dead.
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static void ReplaceLandingPadVal(Function &F, Instruction *Inst, Value *ExnAddr,
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Value *SelAddr) {
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if (Inst->use_empty()) return;
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while (!Inst->use_empty()) {
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Instruction *I = cast<Instruction>(Inst->use_back());
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if (PHINode *PN = dyn_cast<PHINode>(I)) {
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ReplaceLandingPadVal(F, PN, ExnAddr, SelAddr);
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if (PN->use_empty()) PN->eraseFromParent();
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continue;
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}
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I->replaceUsesOfWith(Inst, CreateLandingPadLoad(F, ExnAddr, SelAddr, I));
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}
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}
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bool SjLjEHPass::insertSjLjEHSupport(Function &F) {
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SmallVector<ReturnInst*,16> Returns;
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SmallVector<UnwindInst*,16> Unwinds;
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SmallVector<InvokeInst*,16> Invokes;
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// Look through the terminators of the basic blocks to find invokes, returns
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// and unwinds.
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for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
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if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
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// Remember all return instructions in case we insert an invoke into this
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// function.
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Returns.push_back(RI);
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} else if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
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Invokes.push_back(II);
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} else if (UnwindInst *UI = dyn_cast<UnwindInst>(BB->getTerminator())) {
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Unwinds.push_back(UI);
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}
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}
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NumInvokes += Invokes.size();
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NumUnwinds += Unwinds.size();
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// If we don't have any invokes, there's nothing to do.
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if (Invokes.empty()) return false;
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// Find the eh.selector.*, eh.exception and alloca calls.
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//
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// Remember any allocas() that aren't in the entry block, as the
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// jmpbuf saved SP will need to be updated for them.
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//
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// We'll use the first eh.selector to determine the right personality
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// function to use. For SJLJ, we always use the same personality for the
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// whole function, not on a per-selector basis.
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// FIXME: That's a bit ugly. Better way?
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SmallVector<CallInst*,16> EH_Selectors;
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SmallVector<CallInst*,16> EH_Exceptions;
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SmallVector<Instruction*,16> JmpbufUpdatePoints;
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for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
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// Note: Skip the entry block since there's nothing there that interests
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// us. eh.selector and eh.exception shouldn't ever be there, and we
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// want to disregard any allocas that are there.
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//
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// FIXME: This is awkward. The new EH scheme won't need to skip the entry
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// block.
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if (BB == F.begin()) {
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if (InvokeInst *II = dyn_cast<InvokeInst>(F.begin()->getTerminator())) {
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// FIXME: This will be always non-NULL in the new EH.
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if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst())
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if (!PersonalityFn) PersonalityFn = LPI->getPersonalityFn();
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}
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continue;
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}
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for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
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if (CallInst *CI = dyn_cast<CallInst>(I)) {
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if (CI->getCalledFunction() == SelectorFn) {
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if (!PersonalityFn) PersonalityFn = CI->getArgOperand(1);
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EH_Selectors.push_back(CI);
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} else if (CI->getCalledFunction() == ExceptionFn) {
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EH_Exceptions.push_back(CI);
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} else if (CI->getCalledFunction() == StackRestoreFn) {
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JmpbufUpdatePoints.push_back(CI);
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}
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} else if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
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JmpbufUpdatePoints.push_back(AI);
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} else if (InvokeInst *II = dyn_cast<InvokeInst>(I)) {
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// FIXME: This will be always non-NULL in the new EH.
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if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst())
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if (!PersonalityFn) PersonalityFn = LPI->getPersonalityFn();
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}
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}
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}
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|
||||
// If we don't have any eh.selector calls, we can't determine the personality
|
||||
// function. Without a personality function, we can't process exceptions.
|
||||
if (!PersonalityFn) return false;
|
||||
|
||||
// We have invokes, so we need to add register/unregister calls to get this
|
||||
// function onto the global unwind stack.
|
||||
//
|
||||
// First thing we need to do is scan the whole function for values that are
|
||||
// live across unwind edges. Each value that is live across an unwind edge we
|
||||
// spill into a stack location, guaranteeing that there is nothing live across
|
||||
// the unwind edge. This process also splits all critical edges coming out of
|
||||
// invoke's.
|
||||
splitLiveRangesAcrossInvokes(Invokes);
|
||||
|
||||
|
||||
SmallVector<LandingPadInst*, 16> LandingPads;
|
||||
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) {
|
||||
if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator()))
|
||||
// FIXME: This will be always non-NULL in the new EH.
|
||||
if (LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst())
|
||||
LandingPads.push_back(LPI);
|
||||
}
|
||||
|
||||
|
||||
BasicBlock *EntryBB = F.begin();
|
||||
// Create an alloca for the incoming jump buffer ptr and the new jump buffer
|
||||
// that needs to be restored on all exits from the function. This is an
|
||||
// alloca because the value needs to be added to the global context list.
|
||||
unsigned Align = 4; // FIXME: Should be a TLI check?
|
||||
AllocaInst *FunctionContext =
|
||||
new AllocaInst(FunctionContextTy, 0, Align,
|
||||
"fcn_context", F.begin()->begin());
|
||||
|
||||
Value *Idxs[2];
|
||||
Type *Int32Ty = Type::getInt32Ty(F.getContext());
|
||||
Value *Zero = ConstantInt::get(Int32Ty, 0);
|
||||
// We need to also keep around a reference to the call_site field
|
||||
Idxs[0] = Zero;
|
||||
Idxs[1] = ConstantInt::get(Int32Ty, 1);
|
||||
CallSite = GetElementPtrInst::Create(FunctionContext, Idxs, "call_site",
|
||||
EntryBB->getTerminator());
|
||||
|
||||
// The exception selector comes back in context->data[1]
|
||||
Idxs[1] = ConstantInt::get(Int32Ty, 2);
|
||||
Value *FCData = GetElementPtrInst::Create(FunctionContext, Idxs, "fc_data",
|
||||
EntryBB->getTerminator());
|
||||
Idxs[1] = ConstantInt::get(Int32Ty, 1);
|
||||
Value *SelectorAddr = GetElementPtrInst::Create(FCData, Idxs,
|
||||
"exc_selector_gep",
|
||||
EntryBB->getTerminator());
|
||||
// The exception value comes back in context->data[0]
|
||||
Idxs[1] = Zero;
|
||||
Value *ExceptionAddr = GetElementPtrInst::Create(FCData, Idxs,
|
||||
"exception_gep",
|
||||
EntryBB->getTerminator());
|
||||
|
||||
// The result of the eh.selector call will be replaced with a a reference to
|
||||
// the selector value returned in the function context. We leave the selector
|
||||
// itself so the EH analysis later can use it.
|
||||
for (int i = 0, e = EH_Selectors.size(); i < e; ++i) {
|
||||
CallInst *I = EH_Selectors[i];
|
||||
Value *SelectorVal = new LoadInst(SelectorAddr, "select_val", true, I);
|
||||
I->replaceAllUsesWith(SelectorVal);
|
||||
}
|
||||
|
||||
// eh.exception calls are replaced with references to the proper location in
|
||||
// the context. Unlike eh.selector, the eh.exception calls are removed
|
||||
// entirely.
|
||||
for (int i = 0, e = EH_Exceptions.size(); i < e; ++i) {
|
||||
CallInst *I = EH_Exceptions[i];
|
||||
// Possible for there to be duplicates, so check to make sure the
|
||||
// instruction hasn't already been removed.
|
||||
if (!I->getParent()) continue;
|
||||
Value *Val = new LoadInst(ExceptionAddr, "exception", true, I);
|
||||
Type *Ty = Type::getInt8PtrTy(F.getContext());
|
||||
Val = CastInst::Create(Instruction::IntToPtr, Val, Ty, "", I);
|
||||
|
||||
I->replaceAllUsesWith(Val);
|
||||
I->eraseFromParent();
|
||||
}
|
||||
|
||||
for (unsigned i = 0, e = LandingPads.size(); i != e; ++i)
|
||||
ReplaceLandingPadVal(F, LandingPads[i], ExceptionAddr, SelectorAddr);
|
||||
|
||||
// The entry block changes to have the eh.sjlj.setjmp, with a conditional
|
||||
// branch to a dispatch block for non-zero returns. If we return normally,
|
||||
// we're not handling an exception and just register the function context and
|
||||
// continue.
|
||||
|
||||
// Create the dispatch block. The dispatch block is basically a big switch
|
||||
// statement that goes to all of the invoke landing pads.
|
||||
BasicBlock *DispatchBlock =
|
||||
BasicBlock::Create(F.getContext(), "eh.sjlj.setjmp.catch", &F);
|
||||
|
||||
// Insert a load of the callsite in the dispatch block, and a switch on its
|
||||
// value. By default, we issue a trap statement.
|
||||
BasicBlock *TrapBlock =
|
||||
BasicBlock::Create(F.getContext(), "trapbb", &F);
|
||||
CallInst::Create(Intrinsic::getDeclaration(F.getParent(), Intrinsic::trap),
|
||||
"", TrapBlock);
|
||||
new UnreachableInst(F.getContext(), TrapBlock);
|
||||
|
||||
Value *DispatchLoad = new LoadInst(CallSite, "invoke.num", true,
|
||||
DispatchBlock);
|
||||
SwitchInst *DispatchSwitch =
|
||||
SwitchInst::Create(DispatchLoad, TrapBlock, Invokes.size(),
|
||||
DispatchBlock);
|
||||
// Split the entry block to insert the conditional branch for the setjmp.
|
||||
BasicBlock *ContBlock = EntryBB->splitBasicBlock(EntryBB->getTerminator(),
|
||||
"eh.sjlj.setjmp.cont");
|
||||
|
||||
// Populate the Function Context
|
||||
// 1. LSDA address
|
||||
// 2. Personality function address
|
||||
// 3. jmpbuf (save SP, FP and call eh.sjlj.setjmp)
|
||||
|
||||
// LSDA address
|
||||
Idxs[0] = Zero;
|
||||
Idxs[1] = ConstantInt::get(Int32Ty, 4);
|
||||
Value *LSDAFieldPtr =
|
||||
GetElementPtrInst::Create(FunctionContext, Idxs, "lsda_gep",
|
||||
EntryBB->getTerminator());
|
||||
Value *LSDA = CallInst::Create(LSDAAddrFn, "lsda_addr",
|
||||
EntryBB->getTerminator());
|
||||
new StoreInst(LSDA, LSDAFieldPtr, true, EntryBB->getTerminator());
|
||||
|
||||
Idxs[1] = ConstantInt::get(Int32Ty, 3);
|
||||
Value *PersonalityFieldPtr =
|
||||
GetElementPtrInst::Create(FunctionContext, Idxs, "lsda_gep",
|
||||
EntryBB->getTerminator());
|
||||
new StoreInst(PersonalityFn, PersonalityFieldPtr, true,
|
||||
EntryBB->getTerminator());
|
||||
|
||||
// Save the frame pointer.
|
||||
Idxs[1] = ConstantInt::get(Int32Ty, 5);
|
||||
Value *JBufPtr
|
||||
= GetElementPtrInst::Create(FunctionContext, Idxs, "jbuf_gep",
|
||||
EntryBB->getTerminator());
|
||||
Idxs[1] = ConstantInt::get(Int32Ty, 0);
|
||||
Value *FramePtr =
|
||||
GetElementPtrInst::Create(JBufPtr, Idxs, "jbuf_fp_gep",
|
||||
EntryBB->getTerminator());
|
||||
|
||||
Value *Val = CallInst::Create(FrameAddrFn,
|
||||
ConstantInt::get(Int32Ty, 0),
|
||||
"fp",
|
||||
EntryBB->getTerminator());
|
||||
new StoreInst(Val, FramePtr, true, EntryBB->getTerminator());
|
||||
|
||||
// Save the stack pointer.
|
||||
Idxs[1] = ConstantInt::get(Int32Ty, 2);
|
||||
Value *StackPtr =
|
||||
GetElementPtrInst::Create(JBufPtr, Idxs, "jbuf_sp_gep",
|
||||
EntryBB->getTerminator());
|
||||
|
||||
Val = CallInst::Create(StackAddrFn, "sp", EntryBB->getTerminator());
|
||||
new StoreInst(Val, StackPtr, true, EntryBB->getTerminator());
|
||||
|
||||
// Call the setjmp instrinsic. It fills in the rest of the jmpbuf.
|
||||
Value *SetjmpArg =
|
||||
CastInst::Create(Instruction::BitCast, JBufPtr,
|
||||
Type::getInt8PtrTy(F.getContext()), "",
|
||||
EntryBB->getTerminator());
|
||||
Value *DispatchVal = CallInst::Create(BuiltinSetjmpFn, SetjmpArg,
|
||||
"",
|
||||
EntryBB->getTerminator());
|
||||
|
||||
// Add a call to dispatch_setup after the setjmp call. This is expanded to any
|
||||
// target-specific setup that needs to be done.
|
||||
CallInst::Create(DispatchSetupFn, DispatchVal, "", EntryBB->getTerminator());
|
||||
|
||||
// check the return value of the setjmp. non-zero goes to dispatcher.
|
||||
Value *IsNormal = new ICmpInst(EntryBB->getTerminator(),
|
||||
ICmpInst::ICMP_EQ, DispatchVal, Zero,
|
||||
"notunwind");
|
||||
// Nuke the uncond branch.
|
||||
EntryBB->getTerminator()->eraseFromParent();
|
||||
|
||||
// Put in a new condbranch in its place.
|
||||
BranchInst::Create(ContBlock, DispatchBlock, IsNormal, EntryBB);
|
||||
|
||||
// Register the function context and make sure it's known to not throw
|
||||
CallInst *Register =
|
||||
CallInst::Create(RegisterFn, FunctionContext, "",
|
||||
ContBlock->getTerminator());
|
||||
Register->setDoesNotThrow();
|
||||
|
||||
// At this point, we are all set up, update the invoke instructions to mark
|
||||
// their call_site values, and fill in the dispatch switch accordingly.
|
||||
for (unsigned i = 0, e = Invokes.size(); i != e; ++i)
|
||||
markInvokeCallSite(Invokes[i], i+1, CallSite, DispatchSwitch);
|
||||
|
||||
// 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);
|
||||
} else if (ResumeInst *RI = dyn_cast<ResumeInst>(I)) {
|
||||
insertCallSiteStore(RI, -1, CallSite);
|
||||
}
|
||||
}
|
||||
|
||||
// Replace all unwinds with a branch to the unwind handler.
|
||||
// ??? Should this ever happen with sjlj exceptions?
|
||||
for (unsigned i = 0, e = Unwinds.size(); i != e; ++i) {
|
||||
BranchInst::Create(TrapBlock, Unwinds[i]);
|
||||
Unwinds[i]->eraseFromParent();
|
||||
}
|
||||
|
||||
// Following any allocas not in the entry block, update the saved SP in the
|
||||
// jmpbuf to the new value.
|
||||
for (unsigned i = 0, e = JmpbufUpdatePoints.size(); i != e; ++i) {
|
||||
Instruction *AI = JmpbufUpdatePoints[i];
|
||||
Instruction *StackAddr = CallInst::Create(StackAddrFn, "sp");
|
||||
StackAddr->insertAfter(AI);
|
||||
Instruction *StoreStackAddr = new StoreInst(StackAddr, StackPtr, true);
|
||||
StoreStackAddr->insertAfter(StackAddr);
|
||||
}
|
||||
|
||||
// Finally, for any returns from this function, if this function contains an
|
||||
// invoke, add a call to unregister the function context.
|
||||
for (unsigned i = 0, e = Returns.size(); i != e; ++i)
|
||||
CallInst::Create(UnregisterFn, FunctionContext, "", Returns[i]);
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
/// setupFunctionContext - Allocate the function context on the stack and fill
|
||||
/// it with all of the data that we know at this point.
|
||||
Value *SjLjEHPass::
|
||||
|
|
@ -871,7 +298,7 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F,
|
|||
}
|
||||
|
||||
// Find all of the blocks that this value is live in.
|
||||
std::set<BasicBlock*> LiveBBs;
|
||||
SmallPtrSet<BasicBlock*, 64> LiveBBs;
|
||||
LiveBBs.insert(Inst->getParent());
|
||||
while (!Users.empty()) {
|
||||
Instruction *U = Users.back();
|
||||
|
|
@ -895,6 +322,7 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F,
|
|||
BasicBlock *UnwindBlock = Invokes[i]->getUnwindDest();
|
||||
if (UnwindBlock != BB && LiveBBs.count(UnwindBlock)) {
|
||||
NeedsSpill = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -903,8 +331,8 @@ void SjLjEHPass::lowerAcrossUnwindEdges(Function &F,
|
|||
// the value to be reloaded from the stack slot, even those that aren't
|
||||
// in the unwind blocks. We should be more selective.
|
||||
if (NeedsSpill) {
|
||||
++NumSpilled;
|
||||
DemoteRegToStack(*Inst, true);
|
||||
++NumSpilled;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -950,6 +378,8 @@ bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) {
|
|||
|
||||
if (Invokes.empty()) return false;
|
||||
|
||||
NumInvokes += Invokes.size();
|
||||
|
||||
lowerIncomingArguments(F);
|
||||
lowerAcrossUnwindEdges(F, Invokes);
|
||||
|
||||
|
|
@ -1039,10 +469,6 @@ bool SjLjEHPass::setupEntryBlockAndCallSites(Function &F) {
|
|||
}
|
||||
|
||||
bool SjLjEHPass::runOnFunction(Function &F) {
|
||||
bool Res = false;
|
||||
if (!DisableOldSjLjEH)
|
||||
Res = insertSjLjEHSupport(F);
|
||||
else
|
||||
Res = setupEntryBlockAndCallSites(F);
|
||||
bool Res = setupEntryBlockAndCallSites(F);
|
||||
return Res;
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue