/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp

Bug Summary

File:	lib/CodeGen/WinEHPrepare.cpp
Location:	line 2510, column 23
Description:	Value stored to 'SuccBB' during its initialization is never read

Annotated Source Code

1	//===-- WinEHPrepare - Prepare exception handling for code generation ---===//
2	//
3	// The LLVM Compiler Infrastructure
4	//
5	// This file is distributed under the University of Illinois Open Source
6	// License. See LICENSE.TXT for details.
7	//
8	//===----------------------------------------------------------------------===//
9	//
10	// This pass lowers LLVM IR exception handling into something closer to what the
11	// backend wants for functions using a personality function from a runtime
12	// provided by MSVC. Functions with other personality functions are left alone
13	// and may be prepared by other passes. In particular, all supported MSVC
14	// personality functions require cleanup code to be outlined, and the C++
15	// personality requires catch handler code to be outlined.
16	//
17	//===----------------------------------------------------------------------===//
18
19	#include "llvm/CodeGen/Passes.h"
20	#include "llvm/ADT/MapVector.h"
21	#include "llvm/ADT/STLExtras.h"
22	#include "llvm/ADT/SmallSet.h"
23	#include "llvm/ADT/SetVector.h"
24	#include "llvm/ADT/Triple.h"
25	#include "llvm/ADT/TinyPtrVector.h"
26	#include "llvm/Analysis/CFG.h"
27	#include "llvm/Analysis/LibCallSemantics.h"
28	#include "llvm/Analysis/TargetLibraryInfo.h"
29	#include "llvm/CodeGen/WinEHFuncInfo.h"
30	#include "llvm/IR/Dominators.h"
31	#include "llvm/IR/Function.h"
32	#include "llvm/IR/IRBuilder.h"
33	#include "llvm/IR/Instructions.h"
34	#include "llvm/IR/IntrinsicInst.h"
35	#include "llvm/IR/Module.h"
36	#include "llvm/IR/PatternMatch.h"
37	#include "llvm/MC/MCSymbol.h"
38	#include "llvm/Pass.h"
39	#include "llvm/Support/Debug.h"
40	#include "llvm/Support/raw_ostream.h"
41	#include "llvm/Transforms/Utils/BasicBlockUtils.h"
42	#include "llvm/Transforms/Utils/Cloning.h"
43	#include "llvm/Transforms/Utils/Local.h"
44	#include "llvm/Transforms/Utils/PromoteMemToReg.h"
45	#include "llvm/Transforms/Utils/SSAUpdater.h"
46	#include <memory>
47
48	using namespace llvm;
49	using namespace llvm::PatternMatch;
50
51	#define DEBUG_TYPE"winehprepare" "winehprepare"
52
53	static cl::opt<bool> DisableDemotion(
54	"disable-demotion", cl::Hidden,
55	cl::desc(
56	"Clone multicolor basic blocks but do not demote cross funclet values"),
57	cl::init(false));
58
59	static cl::opt<bool> DisableCleanups(
60	"disable-cleanups", cl::Hidden,
61	cl::desc("Do not remove implausible terminators or other similar cleanups"),
62	cl::init(false));
63
64	namespace {
65
66	// This map is used to model frame variable usage during outlining, to
67	// construct a structure type to hold the frame variables in a frame
68	// allocation block, and to remap the frame variable allocas (including
69	// spill locations as needed) to GEPs that get the variable from the
70	// frame allocation structure.
71	typedef MapVector<Value , TinyPtrVector<AllocaInst >> FrameVarInfoMap;
72
73	// TinyPtrVector cannot hold nullptr, so we need our own sentinel that isn't
74	// quite null.
75	AllocaInst *getCatchObjectSentinel() {
76	return static_cast<AllocaInst *>(nullptr) + 1;
77	}
78
79	typedef SmallSet<BasicBlock *, 4> VisitedBlockSet;
80
81	class LandingPadActions;
82	class LandingPadMap;
83
84	typedef DenseMap<const BasicBlock , CatchHandler > CatchHandlerMapTy;
85	typedef DenseMap<const BasicBlock , CleanupHandler > CleanupHandlerMapTy;
86
87	class WinEHPrepare : public FunctionPass {
88	public:
89	static char ID; // Pass identification, replacement for typeid.
90	WinEHPrepare(const TargetMachine *TM = nullptr)
91	: FunctionPass(ID) {
92	if (TM)
93	TheTriple = TM->getTargetTriple();
94	}
95
96	bool runOnFunction(Function &Fn) override;
97
98	bool doFinalization(Module &M) override;
99
100	void getAnalysisUsage(AnalysisUsage &AU) const override;
101
102	const char *getPassName() const override {
103	return "Windows exception handling preparation";
104	}
105
106	private:
107	bool prepareExceptionHandlers(Function &F,
108	SmallVectorImpl<LandingPadInst *> &LPads);
109	void identifyEHBlocks(Function &F, SmallVectorImpl<LandingPadInst *> &LPads);
110	void promoteLandingPadValues(LandingPadInst *LPad);
111	void demoteValuesLiveAcrossHandlers(Function &F,
112	SmallVectorImpl<LandingPadInst *> &LPads);
113	void findSEHEHReturnPoints(Function &F,
114	SetVector<BasicBlock *> &EHReturnBlocks);
115	void findCXXEHReturnPoints(Function &F,
116	SetVector<BasicBlock *> &EHReturnBlocks);
117	void getPossibleReturnTargets(Function ParentF, Function HandlerF,
118	SetVector<BasicBlock*> &Targets);
119	void completeNestedLandingPad(Function *ParentFn,
120	LandingPadInst *OutlinedLPad,
121	const LandingPadInst *OriginalLPad,
122	FrameVarInfoMap &VarInfo);
123	Function createHandlerFunc(Function ParentFn, Type *RetTy,
124	const Twine &Name, Module M, Value &ParentFP);
125	bool outlineHandler(ActionHandler Action, Function SrcFn,
126	LandingPadInst LPad, BasicBlock StartBB,
127	FrameVarInfoMap &VarInfo);
128	void addStubInvokeToHandlerIfNeeded(Function *Handler);
129
130	void mapLandingPadBlocks(LandingPadInst *LPad, LandingPadActions &Actions);
131	CatchHandler findCatchHandler(BasicBlock BB, BasicBlock *&NextBB,
132	VisitedBlockSet &VisitedBlocks);
133	void findCleanupHandlers(LandingPadActions &Actions, BasicBlock *StartBB,
134	BasicBlock *EndBB);
135
136	void processSEHCatchHandler(CatchHandler Handler, BasicBlock StartBB);
137	void insertPHIStores(PHINode OriginalPHI, AllocaInst SpillSlot);
138	void
139	insertPHIStore(BasicBlock PredBlock, Value PredVal, AllocaInst *SpillSlot,
140	SmallVectorImpl<std::pair<BasicBlock , Value >> &Worklist);
141	AllocaInst insertPHILoads(PHINode PN, Function &F);
142	void replaceUseWithLoad(Value V, Use &U, AllocaInst &SpillSlot,
143	DenseMap<BasicBlock , Value > &Loads, Function &F);
144	void demoteNonlocalUses(Value V, std::set<BasicBlock > &ColorsForBB,
145	Function &F);
146	bool prepareExplicitEH(Function &F,
147	SmallVectorImpl<BasicBlock *> &EntryBlocks);
148	void replaceTerminatePadWithCleanup(Function &F);
149	void colorFunclets(Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks);
150	void demotePHIsOnFunclets(Function &F);
151	void demoteUsesBetweenFunclets(Function &F);
152	void demoteArgumentUses(Function &F);
153	void cloneCommonBlocks(Function &F,
154	SmallVectorImpl<BasicBlock *> &EntryBlocks);
155	void removeImplausibleTerminators(Function &F);
156	void cleanupPreparedFunclets(Function &F);
157	void verifyPreparedFunclets(Function &F);
158
159	Triple TheTriple;
160
161	// All fields are reset by runOnFunction.
162	DominatorTree *DT = nullptr;
163	const TargetLibraryInfo *LibInfo = nullptr;
164	EHPersonality Personality = EHPersonality::Unknown;
165	CatchHandlerMapTy CatchHandlerMap;
166	CleanupHandlerMapTy CleanupHandlerMap;
167	DenseMap<const LandingPadInst *, LandingPadMap> LPadMaps;
168	SmallPtrSet<BasicBlock *, 4> NormalBlocks;
169	SmallPtrSet<BasicBlock *, 4> EHBlocks;
170	SetVector<BasicBlock *> EHReturnBlocks;
171
172	// This maps landing pad instructions found in outlined handlers to
173	// the landing pad instruction in the parent function from which they
174	// were cloned. The cloned/nested landing pad is used as the key
175	// because the landing pad may be cloned into multiple handlers.
176	// This map will be used to add the llvm.eh.actions call to the nested
177	// landing pads after all handlers have been outlined.
178	DenseMap<LandingPadInst , const LandingPadInst > NestedLPtoOriginalLP;
179
180	// This maps blocks in the parent function which are destinations of
181	// catch handlers to cloned blocks in (other) outlined handlers. This
182	// handles the case where a nested landing pads has a catch handler that
183	// returns to a handler function rather than the parent function.
184	// The original block is used as the key here because there should only
185	// ever be one handler function from which the cloned block is not pruned.
186	// The original block will be pruned from the parent function after all
187	// handlers have been outlined. This map will be used to adjust the
188	// return instructions of handlers which return to the block that was
189	// outlined into a handler. This is done after all handlers have been
190	// outlined but before the outlined code is pruned from the parent function.
191	DenseMap<const BasicBlock , BasicBlock > LPadTargetBlocks;
192
193	// Map from outlined handler to call to parent local address. Only used for
194	// 32-bit EH.
195	DenseMap<Function , Value > HandlerToParentFP;
196
197	AllocaInst *SEHExceptionCodeSlot = nullptr;
198
199	std::map<BasicBlock , std::set<BasicBlock >> BlockColors;
200	std::map<BasicBlock , std::set<BasicBlock >> FuncletBlocks;
201	std::map<BasicBlock , std::set<BasicBlock >> FuncletChildren;
202	};
203
204	class WinEHFrameVariableMaterializer : public ValueMaterializer {
205	public:
206	WinEHFrameVariableMaterializer(Function OutlinedFn, Value ParentFP,
207	FrameVarInfoMap &FrameVarInfo);
208	~WinEHFrameVariableMaterializer() override {}
209
210	Value materializeValueFor(Value V) override;
211
212	void escapeCatchObject(Value *V);
213
214	private:
215	FrameVarInfoMap &FrameVarInfo;
216	IRBuilder<> Builder;
217	};
218
219	class LandingPadMap {
220	public:
221	LandingPadMap() : OriginLPad(nullptr) {}
222	void mapLandingPad(const LandingPadInst *LPad);
223
224	bool isInitialized() { return OriginLPad != nullptr; }
225
226	bool isOriginLandingPadBlock(const BasicBlock *BB) const;
227	bool isLandingPadSpecificInst(const Instruction *Inst) const;
228
229	void remapEHValues(ValueToValueMapTy &VMap, Value *EHPtrValue,
230	Value *SelectorValue) const;
231
232	private:
233	const LandingPadInst *OriginLPad;
234	// We will normally only see one of each of these instructions, but
235	// if more than one occurs for some reason we can handle that.
236	TinyPtrVector<const ExtractValueInst *> ExtractedEHPtrs;
237	TinyPtrVector<const ExtractValueInst *> ExtractedSelectors;
238	};
239
240	class WinEHCloningDirectorBase : public CloningDirector {
241	public:
242	WinEHCloningDirectorBase(Function HandlerFn, Value ParentFP,
243	FrameVarInfoMap &VarInfo, LandingPadMap &LPadMap)
244	: Materializer(HandlerFn, ParentFP, VarInfo),
245	SelectorIDType(Type::getInt32Ty(HandlerFn->getContext())),
246	Int8PtrType(Type::getInt8PtrTy(HandlerFn->getContext())),
247	LPadMap(LPadMap), ParentFP(ParentFP) {}
248
249	CloningAction handleInstruction(ValueToValueMapTy &VMap,
250	const Instruction *Inst,
251	BasicBlock *NewBB) override;
252
253	virtual CloningAction handleBeginCatch(ValueToValueMapTy &VMap,
254	const Instruction *Inst,
255	BasicBlock *NewBB) = 0;
256	virtual CloningAction handleEndCatch(ValueToValueMapTy &VMap,
257	const Instruction *Inst,
258	BasicBlock *NewBB) = 0;
259	virtual CloningAction handleTypeIdFor(ValueToValueMapTy &VMap,
260	const Instruction *Inst,
261	BasicBlock *NewBB) = 0;
262	virtual CloningAction handleIndirectBr(ValueToValueMapTy &VMap,
263	const IndirectBrInst *IBr,
264	BasicBlock *NewBB) = 0;
265	virtual CloningAction handleInvoke(ValueToValueMapTy &VMap,
266	const InvokeInst *Invoke,
267	BasicBlock *NewBB) = 0;
268	virtual CloningAction handleResume(ValueToValueMapTy &VMap,
269	const ResumeInst *Resume,
270	BasicBlock *NewBB) = 0;
271	virtual CloningAction handleCompare(ValueToValueMapTy &VMap,
272	const CmpInst *Compare,
273	BasicBlock *NewBB) = 0;
274	virtual CloningAction handleLandingPad(ValueToValueMapTy &VMap,
275	const LandingPadInst *LPad,
276	BasicBlock *NewBB) = 0;
277
278	ValueMaterializer *getValueMaterializer() override { return &Materializer; }
279
280	protected:
281	WinEHFrameVariableMaterializer Materializer;
282	Type *SelectorIDType;
283	Type *Int8PtrType;
284	LandingPadMap &LPadMap;
285
286	/// The value representing the parent frame pointer.
287	Value *ParentFP;
288	};
289
290	class WinEHCatchDirector : public WinEHCloningDirectorBase {
291	public:
292	WinEHCatchDirector(
293	Function CatchFn, Value ParentFP, Value *Selector,
294	FrameVarInfoMap &VarInfo, LandingPadMap &LPadMap,
295	DenseMap<LandingPadInst , const LandingPadInst > &NestedLPads,
296	DominatorTree DT, SmallPtrSetImpl<BasicBlock > &EHBlocks)
297	: WinEHCloningDirectorBase(CatchFn, ParentFP, VarInfo, LPadMap),
298	CurrentSelector(Selector->stripPointerCasts()),
299	ExceptionObjectVar(nullptr), NestedLPtoOriginalLP(NestedLPads),
300	DT(DT), EHBlocks(EHBlocks) {}
301
302	CloningAction handleBeginCatch(ValueToValueMapTy &VMap,
303	const Instruction *Inst,
304	BasicBlock *NewBB) override;
305	CloningAction handleEndCatch(ValueToValueMapTy &VMap, const Instruction *Inst,
306	BasicBlock *NewBB) override;
307	CloningAction handleTypeIdFor(ValueToValueMapTy &VMap,
308	const Instruction *Inst,
309	BasicBlock *NewBB) override;
310	CloningAction handleIndirectBr(ValueToValueMapTy &VMap,
311	const IndirectBrInst *IBr,
312	BasicBlock *NewBB) override;
313	CloningAction handleInvoke(ValueToValueMapTy &VMap, const InvokeInst *Invoke,
314	BasicBlock *NewBB) override;
315	CloningAction handleResume(ValueToValueMapTy &VMap, const ResumeInst *Resume,
316	BasicBlock *NewBB) override;
317	CloningAction handleCompare(ValueToValueMapTy &VMap, const CmpInst *Compare,
318	BasicBlock *NewBB) override;
319	CloningAction handleLandingPad(ValueToValueMapTy &VMap,
320	const LandingPadInst *LPad,
321	BasicBlock *NewBB) override;
322
323	Value *getExceptionVar() { return ExceptionObjectVar; }
324	TinyPtrVector<BasicBlock *> &getReturnTargets() { return ReturnTargets; }
325
326	private:
327	Value *CurrentSelector;
328
329	Value *ExceptionObjectVar;
330	TinyPtrVector<BasicBlock *> ReturnTargets;
331
332	// This will be a reference to the field of the same name in the WinEHPrepare
333	// object which instantiates this WinEHCatchDirector object.
334	DenseMap<LandingPadInst , const LandingPadInst > &NestedLPtoOriginalLP;
335	DominatorTree *DT;
336	SmallPtrSetImpl<BasicBlock *> &EHBlocks;
337	};
338
339	class WinEHCleanupDirector : public WinEHCloningDirectorBase {
340	public:
341	WinEHCleanupDirector(Function CleanupFn, Value ParentFP,
342	FrameVarInfoMap &VarInfo, LandingPadMap &LPadMap)
343	: WinEHCloningDirectorBase(CleanupFn, ParentFP, VarInfo,
344	LPadMap) {}
345
346	CloningAction handleBeginCatch(ValueToValueMapTy &VMap,
347	const Instruction *Inst,
348	BasicBlock *NewBB) override;
349	CloningAction handleEndCatch(ValueToValueMapTy &VMap, const Instruction *Inst,
350	BasicBlock *NewBB) override;
351	CloningAction handleTypeIdFor(ValueToValueMapTy &VMap,
352	const Instruction *Inst,
353	BasicBlock *NewBB) override;
354	CloningAction handleIndirectBr(ValueToValueMapTy &VMap,
355	const IndirectBrInst *IBr,
356	BasicBlock *NewBB) override;
357	CloningAction handleInvoke(ValueToValueMapTy &VMap, const InvokeInst *Invoke,
358	BasicBlock *NewBB) override;
359	CloningAction handleResume(ValueToValueMapTy &VMap, const ResumeInst *Resume,
360	BasicBlock *NewBB) override;
361	CloningAction handleCompare(ValueToValueMapTy &VMap, const CmpInst *Compare,
362	BasicBlock *NewBB) override;
363	CloningAction handleLandingPad(ValueToValueMapTy &VMap,
364	const LandingPadInst *LPad,
365	BasicBlock *NewBB) override;
366	};
367
368	class LandingPadActions {
369	public:
370	LandingPadActions() : HasCleanupHandlers(false) {}
371
372	void insertCatchHandler(CatchHandler *Action) { Actions.push_back(Action); }
373	void insertCleanupHandler(CleanupHandler *Action) {
374	Actions.push_back(Action);
375	HasCleanupHandlers = true;
376	}
377
378	bool includesCleanup() const { return HasCleanupHandlers; }
379
380	SmallVectorImpl<ActionHandler *> &actions() { return Actions; }
381	SmallVectorImpl<ActionHandler *>::iterator begin() { return Actions.begin(); }
382	SmallVectorImpl<ActionHandler *>::iterator end() { return Actions.end(); }
383
384	private:
385	// Note that this class does not own the ActionHandler objects in this vector.
386	// The ActionHandlers are owned by the CatchHandlerMap and CleanupHandlerMap
387	// in the WinEHPrepare class.
388	SmallVector<ActionHandler *, 4> Actions;
389	bool HasCleanupHandlers;
390	};
391
392	} // end anonymous namespace
393
394	char WinEHPrepare::ID = 0;
395	INITIALIZE_TM_PASS(WinEHPrepare, "winehprepare", "Prepare Windows exceptions",static void* initializeWinEHPreparePassOnce(PassRegistry & Registry) { PassInfo PI = new PassInfo("Prepare Windows exceptions" , "winehprepare", & WinEHPrepare ::ID, PassInfo::NormalCtor_t (callDefaultCtor< WinEHPrepare >), false, false, PassInfo ::TargetMachineCtor_t(callTargetMachineCtor< WinEHPrepare > )); Registry.registerPass(PI, true); return PI; } void llvm:: initializeWinEHPreparePass(PassRegistry &Registry) { static volatile sys::cas_flag initialized = 0; sys::cas_flag old_val = sys::CompareAndSwap(&initialized, 1, 0); if (old_val == 0) { initializeWinEHPreparePassOnce(Registry); sys::MemoryFence (); ; ; initialized = 2; ; } else { sys::cas_flag tmp = initialized ; sys::MemoryFence(); while (tmp != 2) { tmp = initialized; sys ::MemoryFence(); } } ; }
396	false, false)static void* initializeWinEHPreparePassOnce(PassRegistry & Registry) { PassInfo PI = new PassInfo("Prepare Windows exceptions" , "winehprepare", & WinEHPrepare ::ID, PassInfo::NormalCtor_t (callDefaultCtor< WinEHPrepare >), false, false, PassInfo ::TargetMachineCtor_t(callTargetMachineCtor< WinEHPrepare > )); Registry.registerPass(PI, true); return PI; } void llvm:: initializeWinEHPreparePass(PassRegistry &Registry) { static volatile sys::cas_flag initialized = 0; sys::cas_flag old_val = sys::CompareAndSwap(&initialized, 1, 0); if (old_val == 0) { initializeWinEHPreparePassOnce(Registry); sys::MemoryFence (); ; ; initialized = 2; ; } else { sys::cas_flag tmp = initialized ; sys::MemoryFence(); while (tmp != 2) { tmp = initialized; sys ::MemoryFence(); } } ; }
397
398	FunctionPass llvm::createWinEHPass(const TargetMachine TM) {
399	return new WinEHPrepare(TM);
400	}
401
402	static bool
403	findExceptionalConstructs(Function &Fn,
404	SmallVectorImpl<LandingPadInst *> &LPads,
405	SmallVectorImpl<ResumeInst *> &Resumes,
406	SmallVectorImpl<BasicBlock *> &EntryBlocks) {
407	bool ForExplicitEH = false;
408	for (BasicBlock &BB : Fn) {
409	Instruction *First = BB.getFirstNonPHI();
410	if (auto *LP = dyn_cast<LandingPadInst>(First)) {
411	LPads.push_back(LP);
412	} else if (First->isEHPad()) {
413	if (!ForExplicitEH)
414	EntryBlocks.push_back(&Fn.getEntryBlock());
415	if (!isa<CatchEndPadInst>(First) && !isa<CleanupEndPadInst>(First))
416	EntryBlocks.push_back(&BB);
417	ForExplicitEH = true;
418	}
419	if (auto *Resume = dyn_cast<ResumeInst>(BB.getTerminator()))
420	Resumes.push_back(Resume);
421	}
422	return ForExplicitEH;
423	}
424
425	bool WinEHPrepare::runOnFunction(Function &Fn) {
426	if (!Fn.hasPersonalityFn())
427	return false;
428
429	// No need to prepare outlined handlers.
430	if (Fn.hasFnAttribute("wineh-parent"))
431	return false;
432
433	// Classify the personality to see what kind of preparation we need.
434	Personality = classifyEHPersonality(Fn.getPersonalityFn());
435
436	// Do nothing if this is not a funclet-based personality.
437	if (!isFuncletEHPersonality(Personality))
438	return false;
439
440	// Remove unreachable blocks. It is not valuable to assign them a color and
441	// their existence can trick us into thinking values are alive when they are
442	// not.
443	removeUnreachableBlocks(Fn);
444
445	SmallVector<LandingPadInst *, 4> LPads;
446	SmallVector<ResumeInst *, 4> Resumes;
447	SmallVector<BasicBlock *, 4> EntryBlocks;
448	bool ForExplicitEH =
449	findExceptionalConstructs(Fn, LPads, Resumes, EntryBlocks);
450
451	if (ForExplicitEH)
452	return prepareExplicitEH(Fn, EntryBlocks);
453
454	// No need to prepare functions that lack landing pads.
455	if (LPads.empty())
456	return false;
457
458	DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
459	LibInfo = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
460
461	// If there were any landing pads, prepareExceptionHandlers will make changes.
462	prepareExceptionHandlers(Fn, LPads);
463	return true;
464	}
465
466	bool WinEHPrepare::doFinalization(Module &M) { return false; }
467
468	void WinEHPrepare::getAnalysisUsage(AnalysisUsage &AU) const {
469	AU.addRequired<DominatorTreeWrapperPass>();
470	AU.addRequired<TargetLibraryInfoWrapperPass>();
471	}
472
473	static bool isSelectorDispatch(BasicBlock BB, BasicBlock &CatchHandler,
474	Constant &Selector, BasicBlock &NextBB);
475
476	// Finds blocks reachable from the starting set Worklist. Does not follow unwind
477	// edges or blocks listed in StopPoints.
478	static void findReachableBlocks(SmallPtrSetImpl<BasicBlock *> &ReachableBBs,
479	SetVector<BasicBlock *> &Worklist,
480	const SetVector<BasicBlock > StopPoints) {
481	while (!Worklist.empty()) {
482	BasicBlock *BB = Worklist.pop_back_val();
483
484	// Don't cross blocks that we should stop at.
485	if (StopPoints && StopPoints->count(BB))
486	continue;
487
488	if (!ReachableBBs.insert(BB).second)
489	continue; // Already visited.
490
491	// Don't follow unwind edges of invokes.
492	if (auto *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
493	Worklist.insert(II->getNormalDest());
494	continue;
495	}
496
497	// Otherwise, follow all successors.
498	Worklist.insert(succ_begin(BB), succ_end(BB));
499	}
500	}
501
502	// Attempt to find an instruction where a block can be split before
503	// a call to llvm.eh.begincatch and its operands. If the block
504	// begins with the begincatch call or one of its adjacent operands
505	// the block will not be split.
506	static Instruction findBeginCatchSplitPoint(BasicBlock BB,
507	IntrinsicInst *II) {
508	// If the begincatch call is already the first instruction in the block,
509	// don't split.
510	Instruction *FirstNonPHI = BB->getFirstNonPHI();
511	if (II == FirstNonPHI)
512	return nullptr;
513
514	// If either operand is in the same basic block as the instruction and
515	// isn't used by another instruction before the begincatch call, include it
516	// in the split block.
517	auto *Op0 = dyn_cast<Instruction>(II->getOperand(0));
518	auto *Op1 = dyn_cast<Instruction>(II->getOperand(1));
519
520	Instruction *I = II->getPrevNode();
521	Instruction *LastI = II;
522
523	while (I == Op0 \|\| I == Op1) {
524	// If the block begins with one of the operands and there are no other
525	// instructions between the operand and the begincatch call, don't split.
526	if (I == FirstNonPHI)
527	return nullptr;
528
529	LastI = I;
530	I = I->getPrevNode();
531	}
532
533	// If there is at least one instruction in the block before the begincatch
534	// call and its operands, split the block at either the begincatch or
535	// its operand.
536	return LastI;
537	}
538
539	/// Find all points where exceptional control rejoins normal control flow via
540	/// llvm.eh.endcatch. Add them to the normal bb reachability worklist.
541	void WinEHPrepare::findCXXEHReturnPoints(
542	Function &F, SetVector<BasicBlock *> &EHReturnBlocks) {
543	for (auto BBI = F.begin(), BBE = F.end(); BBI != BBE; ++BBI) {
544	BasicBlock *BB = BBI;
545	for (Instruction &I : *BB) {
546	if (match(&I, m_Intrinsic<Intrinsic::eh_begincatch>())) {
547	Instruction *SplitPt =
548	findBeginCatchSplitPoint(BB, cast<IntrinsicInst>(&I));
549	if (SplitPt) {
550	// Split the block before the llvm.eh.begincatch call to allow
551	// cleanup and catch code to be distinguished later.
552	// Do not update BBI because we still need to process the
553	// portion of the block that we are splitting off.
554	SplitBlock(BB, SplitPt, DT);
555	break;
556	}
557	}
558	if (match(&I, m_Intrinsic<Intrinsic::eh_endcatch>())) {
559	// Split the block after the call to llvm.eh.endcatch if there is
560	// anything other than an unconditional branch, or if the successor
561	// starts with a phi.
562	auto *Br = dyn_cast<BranchInst>(I.getNextNode());
563	if (!Br \|\| !Br->isUnconditional() \|\|
564	isa<PHINode>(Br->getSuccessor(0)->begin())) {
565	DEBUG(dbgs() << "splitting block " << BB->getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "splitting block " << BB->getName() << " with llvm.eh.endcatch\n"; } } while (0)
566	<< " with llvm.eh.endcatch\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "splitting block " << BB->getName() << " with llvm.eh.endcatch\n"; } } while (0);
567	BBI = SplitBlock(BB, I.getNextNode(), DT);
568	}
569	// The next BB is normal control flow.
570	EHReturnBlocks.insert(BB->getTerminator()->getSuccessor(0));
571	break;
572	}
573	}
574	}
575	}
576
577	static bool isCatchAllLandingPad(const BasicBlock *BB) {
578	const LandingPadInst *LP = BB->getLandingPadInst();
579	if (!LP)
580	return false;
581	unsigned N = LP->getNumClauses();
582	return (N > 0 && LP->isCatch(N - 1) &&
583	isa<ConstantPointerNull>(LP->getClause(N - 1)));
584	}
585
586	/// Find all points where exceptions control rejoins normal control flow via
587	/// selector dispatch.
588	void WinEHPrepare::findSEHEHReturnPoints(
589	Function &F, SetVector<BasicBlock *> &EHReturnBlocks) {
590	for (auto BBI = F.begin(), BBE = F.end(); BBI != BBE; ++BBI) {
591	BasicBlock *BB = BBI;
592	// If the landingpad is a catch-all, treat the whole lpad as if it is
593	// reachable from normal control flow.
594	// FIXME: This is imprecise. We need a better way of identifying where a
595	// catch-all starts and cleanups stop. As far as LLVM is concerned, there
596	// is no difference.
597	if (isCatchAllLandingPad(BB)) {
598	EHReturnBlocks.insert(BB);
599	continue;
600	}
601
602	BasicBlock *CatchHandler;
603	BasicBlock *NextBB;
604	Constant *Selector;
605	if (isSelectorDispatch(BB, CatchHandler, Selector, NextBB)) {
606	// Split the edge if there are multiple predecessors. This creates a place
607	// where we can insert EH recovery code.
608	if (!CatchHandler->getSinglePredecessor()) {
609	DEBUG(dbgs() << "splitting EH return edge from " << BB->getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "splitting EH return edge from " << BB->getName() << " to " << CatchHandler ->getName() << '\n'; } } while (0)
610	<< " to " << CatchHandler->getName() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "splitting EH return edge from " << BB->getName() << " to " << CatchHandler ->getName() << '\n'; } } while (0);
611	BBI = CatchHandler = SplitCriticalEdge(
612	BB, std::find(succ_begin(BB), succ_end(BB), CatchHandler));
613	}
614	EHReturnBlocks.insert(CatchHandler);
615	}
616	}
617	}
618
619	void WinEHPrepare::identifyEHBlocks(Function &F,
620	SmallVectorImpl<LandingPadInst *> &LPads) {
621	DEBUG(dbgs() << "Demoting values live across exception handlers in function "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Demoting values live across exception handlers in function " << F.getName() << '\n'; } } while (0)
622	<< F.getName() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Demoting values live across exception handlers in function " << F.getName() << '\n'; } } while (0);
623
624	// Build a set of all non-exceptional blocks and exceptional blocks.
625	// - Non-exceptional blocks are blocks reachable from the entry block while
626	// not following invoke unwind edges.
627	// - Exceptional blocks are blocks reachable from landingpads. Analysis does
628	// not follow llvm.eh.endcatch blocks, which mark a transition from
629	// exceptional to normal control.
630
631	if (Personality == EHPersonality::MSVC_CXX)
632	findCXXEHReturnPoints(F, EHReturnBlocks);
633	else
634	findSEHEHReturnPoints(F, EHReturnBlocks);
635
636	DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "identified the following blocks as EH return points:\n" ; for (BasicBlock *BB : EHReturnBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
637	dbgs() << "identified the following blocks as EH return points:\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "identified the following blocks as EH return points:\n" ; for (BasicBlock *BB : EHReturnBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
638	for (BasicBlock BB : EHReturnBlocks)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "identified the following blocks as EH return points:\n" ; for (BasicBlock BB : EHReturnBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
639	dbgs() << " " << BB->getName() << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "identified the following blocks as EH return points:\n" ; for (BasicBlock *BB : EHReturnBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
640	})do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "identified the following blocks as EH return points:\n" ; for (BasicBlock *BB : EHReturnBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0);
641
642	// Join points should not have phis at this point, unless they are a
643	// landingpad, in which case we will demote their phis later.
644	#ifndef NDEBUG
645	for (BasicBlock *BB : EHReturnBlocks)
646	assert((BB->isLandingPad() \|\| !isa<PHINode>(BB->begin())) &&(((BB->isLandingPad() \|\| !isa<PHINode>(BB->begin( ))) && "non-lpad EH return block has phi") ? static_cast <void> (0) : __assert_fail ("(BB->isLandingPad() \|\| !isa<PHINode>(BB->begin())) && \"non-lpad EH return block has phi\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 647, __PRETTY_FUNCTION__))
647	"non-lpad EH return block has phi")(((BB->isLandingPad() \|\| !isa<PHINode>(BB->begin( ))) && "non-lpad EH return block has phi") ? static_cast <void> (0) : __assert_fail ("(BB->isLandingPad() \|\| !isa<PHINode>(BB->begin())) && \"non-lpad EH return block has phi\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 647, __PRETTY_FUNCTION__));
648	#endif
649
650	// Normal blocks are the blocks reachable from the entry block and all EH
651	// return points.
652	SetVector<BasicBlock *> Worklist;
653	Worklist = EHReturnBlocks;
654	Worklist.insert(&F.getEntryBlock());
655	findReachableBlocks(NormalBlocks, Worklist, nullptr);
656	DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "marked the following blocks as normal:\n" ; for (BasicBlock *BB : NormalBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
657	dbgs() << "marked the following blocks as normal:\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "marked the following blocks as normal:\n" ; for (BasicBlock *BB : NormalBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
658	for (BasicBlock BB : NormalBlocks)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "marked the following blocks as normal:\n" ; for (BasicBlock BB : NormalBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
659	dbgs() << " " << BB->getName() << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "marked the following blocks as normal:\n" ; for (BasicBlock *BB : NormalBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
660	})do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "marked the following blocks as normal:\n" ; for (BasicBlock *BB : NormalBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0);
661
662	// Exceptional blocks are the blocks reachable from landingpads that don't
663	// cross EH return points.
664	Worklist.clear();
665	for (auto *LPI : LPads)
666	Worklist.insert(LPI->getParent());
667	findReachableBlocks(EHBlocks, Worklist, &EHReturnBlocks);
668	DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "marked the following blocks as exceptional:\n" ; for (BasicBlock *BB : EHBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
669	dbgs() << "marked the following blocks as exceptional:\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "marked the following blocks as exceptional:\n" ; for (BasicBlock *BB : EHBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
670	for (BasicBlock BB : EHBlocks)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "marked the following blocks as exceptional:\n" ; for (BasicBlock BB : EHBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
671	dbgs() << " " << BB->getName() << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "marked the following blocks as exceptional:\n" ; for (BasicBlock *BB : EHBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0)
672	})do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "marked the following blocks as exceptional:\n" ; for (BasicBlock *BB : EHBlocks) dbgs() << " " << BB->getName() << '\n'; }; } } while (0);
673
674	}
675
676	/// Ensure that all values live into and out of exception handlers are stored
677	/// in memory.
678	/// FIXME: This falls down when values are defined in one handler and live into
679	/// another handler. For example, a cleanup defines a value used only by a
680	/// catch handler.
681	void WinEHPrepare::demoteValuesLiveAcrossHandlers(
682	Function &F, SmallVectorImpl<LandingPadInst *> &LPads) {
683	DEBUG(dbgs() << "Demoting values live across exception handlers in function "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Demoting values live across exception handlers in function " << F.getName() << '\n'; } } while (0)
684	<< F.getName() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Demoting values live across exception handlers in function " << F.getName() << '\n'; } } while (0);
685
686	// identifyEHBlocks() should have been called before this function.
687	assert(!NormalBlocks.empty())((!NormalBlocks.empty()) ? static_cast<void> (0) : __assert_fail ("!NormalBlocks.empty()", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 687, __PRETTY_FUNCTION__));
688
689	// Try to avoid demoting EH pointer and selector values. They get in the way
690	// of our pattern matching.
691	SmallPtrSet<Instruction *, 10> EHVals;
692	for (BasicBlock &BB : F) {
693	LandingPadInst *LP = BB.getLandingPadInst();
694	if (!LP)
695	continue;
696	EHVals.insert(LP);
697	for (User *U : LP->users()) {
698	auto *EI = dyn_cast<ExtractValueInst>(U);
699	if (!EI)
700	continue;
701	EHVals.insert(EI);
702	for (User *U2 : EI->users()) {
703	if (auto *PN = dyn_cast<PHINode>(U2))
704	EHVals.insert(PN);
705	}
706	}
707	}
708
709	SetVector<Argument *> ArgsToDemote;
710	SetVector<Instruction *> InstrsToDemote;
711	for (BasicBlock &BB : F) {
712	bool IsNormalBB = NormalBlocks.count(&BB);
713	bool IsEHBB = EHBlocks.count(&BB);
714	if (!IsNormalBB && !IsEHBB)
715	continue; // Blocks that are neither normal nor EH are unreachable.
716	for (Instruction &I : BB) {
717	for (Value *Op : I.operands()) {
718	// Don't demote static allocas, constants, and labels.
719	if (isa<Constant>(Op) \|\| isa<BasicBlock>(Op) \|\| isa<InlineAsm>(Op))
720	continue;
721	auto *AI = dyn_cast<AllocaInst>(Op);
722	if (AI && AI->isStaticAlloca())
723	continue;
724
725	if (auto *Arg = dyn_cast<Argument>(Op)) {
726	if (IsEHBB) {
727	DEBUG(dbgs() << "Demoting argument " << Argdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Demoting argument " << Arg << " used by EH instr: " << I << "\n" ; } } while (0)
728	<< " used by EH instr: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Demoting argument " << *Arg << " used by EH instr: " << I << "\n" ; } } while (0);
729	ArgsToDemote.insert(Arg);
730	}
731	continue;
732	}
733
734	// Don't demote EH values.
735	auto *OpI = cast<Instruction>(Op);
736	if (EHVals.count(OpI))
737	continue;
738
739	BasicBlock *OpBB = OpI->getParent();
740	// If a value is produced and consumed in the same BB, we don't need to
741	// demote it.
742	if (OpBB == &BB)
743	continue;
744	bool IsOpNormalBB = NormalBlocks.count(OpBB);
745	bool IsOpEHBB = EHBlocks.count(OpBB);
746	if (IsNormalBB != IsOpNormalBB \|\| IsEHBB != IsOpEHBB) {
747	DEBUG({do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "Demoting instruction live in-out from EH:\n" ; dbgs() << "Instr: " << *OpI << '\n'; dbgs () << "User: " << I << '\n'; }; } } while ( 0)
748	dbgs() << "Demoting instruction live in-out from EH:\n";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "Demoting instruction live in-out from EH:\n" ; dbgs() << "Instr: " << *OpI << '\n'; dbgs () << "User: " << I << '\n'; }; } } while ( 0)
749	dbgs() << "Instr: " << OpI << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "Demoting instruction live in-out from EH:\n" ; dbgs() << "Instr: " << OpI << '\n'; dbgs () << "User: " << I << '\n'; }; } } while ( 0)
750	dbgs() << "User: " << I << '\n';do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "Demoting instruction live in-out from EH:\n" ; dbgs() << "Instr: " << *OpI << '\n'; dbgs () << "User: " << I << '\n'; }; } } while ( 0)
751	})do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { { dbgs() << "Demoting instruction live in-out from EH:\n" ; dbgs() << "Instr: " << *OpI << '\n'; dbgs () << "User: " << I << '\n'; }; } } while ( 0);
752	InstrsToDemote.insert(OpI);
753	}
754	}
755	}
756	}
757
758	// Demote values live into and out of handlers.
759	// FIXME: This demotion is inefficient. We should insert spills at the point
760	// of definition, insert one reload in each handler that uses the value, and
761	// insert reloads in the BB used to rejoin normal control flow.
762	Instruction *AllocaInsertPt = F.getEntryBlock().getFirstInsertionPt();
763	for (Instruction *I : InstrsToDemote)
764	DemoteRegToStack(*I, false, AllocaInsertPt);
765
766	// Demote arguments separately, and only for uses in EH blocks.
767	for (Argument *Arg : ArgsToDemote) {
768	auto *Slot = new AllocaInst(Arg->getType(), nullptr,
769	Arg->getName() + ".reg2mem", AllocaInsertPt);
770	SmallVector<User *, 4> Users(Arg->user_begin(), Arg->user_end());
771	for (User *U : Users) {
772	auto *I = dyn_cast<Instruction>(U);
773	if (I && EHBlocks.count(I->getParent())) {
774	auto *Reload = new LoadInst(Slot, Arg->getName() + ".reload", false, I);
775	U->replaceUsesOfWith(Arg, Reload);
776	}
777	}
778	new StoreInst(Arg, Slot, AllocaInsertPt);
779	}
780
781	// Demote landingpad phis, as the landingpad will be removed from the machine
782	// CFG.
783	for (LandingPadInst *LPI : LPads) {
784	BasicBlock *BB = LPI->getParent();
785	while (auto *Phi = dyn_cast<PHINode>(BB->begin()))
786	DemotePHIToStack(Phi, AllocaInsertPt);
787	}
788
789	DEBUG(dbgs() << "Demoted " << InstrsToDemote.size() << " instructions and "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Demoted " << InstrsToDemote .size() << " instructions and " << ArgsToDemote.size () << " arguments for WinEHPrepare\n\n"; } } while (0)
790	<< ArgsToDemote.size() << " arguments for WinEHPrepare\n\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Demoted " << InstrsToDemote .size() << " instructions and " << ArgsToDemote.size () << " arguments for WinEHPrepare\n\n"; } } while (0);
791	}
792
793	bool WinEHPrepare::prepareExceptionHandlers(
794	Function &F, SmallVectorImpl<LandingPadInst *> &LPads) {
795	// Don't run on functions that are already prepared.
796	for (LandingPadInst *LPad : LPads) {
797	BasicBlock *LPadBB = LPad->getParent();
798	for (Instruction &Inst : *LPadBB)
799	if (match(&Inst, m_Intrinsic<Intrinsic::eh_actions>()))
800	return false;
801	}
802
803	identifyEHBlocks(F, LPads);
804	demoteValuesLiveAcrossHandlers(F, LPads);
805
806	// These containers are used to re-map frame variables that are used in
807	// outlined catch and cleanup handlers. They will be populated as the
808	// handlers are outlined.
809	FrameVarInfoMap FrameVarInfo;
810
811	bool HandlersOutlined = false;
812
813	Module *M = F.getParent();
814	LLVMContext &Context = M->getContext();
815
816	// Create a new function to receive the handler contents.
817	PointerType *Int8PtrType = Type::getInt8PtrTy(Context);
818	Type *Int32Type = Type::getInt32Ty(Context);
819	Function *ActionIntrin = Intrinsic::getDeclaration(M, Intrinsic::eh_actions);
820
821	if (isAsynchronousEHPersonality(Personality)) {
822	// FIXME: Switch the ehptr type to i32 and then switch this.
823	SEHExceptionCodeSlot =
824	new AllocaInst(Int8PtrType, nullptr, "seh_exception_code",
825	F.getEntryBlock().getFirstInsertionPt());
826	}
827
828	// In order to handle the case where one outlined catch handler returns
829	// to a block within another outlined catch handler that would otherwise
830	// be unreachable, we need to outline the nested landing pad before we
831	// outline the landing pad which encloses it.
832	if (!isAsynchronousEHPersonality(Personality))
833	std::sort(LPads.begin(), LPads.end(),
834	[this](LandingPadInst const &L, LandingPadInst const &R) {
835	return DT->properlyDominates(R->getParent(), L->getParent());
836	});
837
838	// This container stores the llvm.eh.recover and IndirectBr instructions
839	// that make up the body of each landing pad after it has been outlined.
840	// We need to defer the population of the target list for the indirectbr
841	// until all landing pads have been outlined so that we can handle the
842	// case of blocks in the target that are reached only from nested
843	// landing pads.
844	SmallVector<std::pair<CallInst, IndirectBrInst >, 4> LPadImpls;
845
846	for (LandingPadInst *LPad : LPads) {
847	// Look for evidence that this landingpad has already been processed.
848	bool LPadHasActionList = false;
849	BasicBlock *LPadBB = LPad->getParent();
850	for (Instruction &Inst : *LPadBB) {
851	if (match(&Inst, m_Intrinsic<Intrinsic::eh_actions>())) {
852	LPadHasActionList = true;
853	break;
854	}
855	}
856
857	// If we've already outlined the handlers for this landingpad,
858	// there's nothing more to do here.
859	if (LPadHasActionList)
860	continue;
861
862	// If either of the values in the aggregate returned by the landing pad is
863	// extracted and stored to memory, promote the stored value to a register.
864	promoteLandingPadValues(LPad);
865
866	LandingPadActions Actions;
867	mapLandingPadBlocks(LPad, Actions);
868
869	HandlersOutlined \|= !Actions.actions().empty();
870	for (ActionHandler *Action : Actions) {
871	if (Action->hasBeenProcessed())
872	continue;
873	BasicBlock *StartBB = Action->getStartBlock();
874
875	// SEH doesn't do any outlining for catches. Instead, pass the handler
876	// basic block addr to llvm.eh.actions and list the block as a return
877	// target.
878	if (isAsynchronousEHPersonality(Personality)) {
879	if (auto *CatchAction = dyn_cast<CatchHandler>(Action)) {
880	processSEHCatchHandler(CatchAction, StartBB);
881	continue;
882	}
883	}
884
885	outlineHandler(Action, &F, LPad, StartBB, FrameVarInfo);
886	}
887
888	// Split the block after the landingpad instruction so that it is just a
889	// call to llvm.eh.actions followed by indirectbr.
890	assert(!isa<PHINode>(LPadBB->begin()) && "lpad phi not removed")((!isa<PHINode>(LPadBB->begin()) && "lpad phi not removed" ) ? static_cast<void> (0) : __assert_fail ("!isa<PHINode>(LPadBB->begin()) && \"lpad phi not removed\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 890, __PRETTY_FUNCTION__));
891	SplitBlock(LPadBB, LPad->getNextNode(), DT);
892	// Erase the branch inserted by the split so we can insert indirectbr.
893	LPadBB->getTerminator()->eraseFromParent();
894
895	// Replace all extracted values with undef and ultimately replace the
896	// landingpad with undef.
897	SmallVector<Instruction *, 4> SEHCodeUses;
898	SmallVector<Instruction *, 4> EHUndefs;
899	for (User *U : LPad->users()) {
900	auto *E = dyn_cast<ExtractValueInst>(U);
901	if (!E)
902	continue;
903	assert(E->getNumIndices() == 1 &&((E->getNumIndices() == 1 && "Unexpected operation: extracting both landing pad values" ) ? static_cast<void> (0) : __assert_fail ("E->getNumIndices() == 1 && \"Unexpected operation: extracting both landing pad values\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 904, __PRETTY_FUNCTION__))
904	"Unexpected operation: extracting both landing pad values")((E->getNumIndices() == 1 && "Unexpected operation: extracting both landing pad values" ) ? static_cast<void> (0) : __assert_fail ("E->getNumIndices() == 1 && \"Unexpected operation: extracting both landing pad values\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 904, __PRETTY_FUNCTION__));
905	unsigned Idx = *E->idx_begin();
906	assert((Idx == 0 \|\| Idx == 1) && "unexpected index")(((Idx == 0 \|\| Idx == 1) && "unexpected index") ? static_cast <void> (0) : __assert_fail ("(Idx == 0 \|\| Idx == 1) && \"unexpected index\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 906, __PRETTY_FUNCTION__));
907	if (Idx == 0 && isAsynchronousEHPersonality(Personality))
908	SEHCodeUses.push_back(E);
909	else
910	EHUndefs.push_back(E);
911	}
912	for (Instruction *E : EHUndefs) {
913	E->replaceAllUsesWith(UndefValue::get(E->getType()));
914	E->eraseFromParent();
915	}
916	LPad->replaceAllUsesWith(UndefValue::get(LPad->getType()));
917
918	// Rewrite uses of the exception pointer to loads of an alloca.
919	while (!SEHCodeUses.empty()) {
920	Instruction *E = SEHCodeUses.pop_back_val();
921	SmallVector<Use *, 4> Uses;
922	for (Use &U : E->uses())
923	Uses.push_back(&U);
924	for (Use *U : Uses) {
925	auto *I = cast<Instruction>(U->getUser());
926	if (isa<ResumeInst>(I))
927	continue;
928	if (auto *Phi = dyn_cast<PHINode>(I))
929	SEHCodeUses.push_back(Phi);
930	else
931	U->set(new LoadInst(SEHExceptionCodeSlot, "sehcode", false, I));
932	}
933	E->replaceAllUsesWith(UndefValue::get(E->getType()));
934	E->eraseFromParent();
935	}
936
937	// Add a call to describe the actions for this landing pad.
938	std::vector<Value *> ActionArgs;
939	for (ActionHandler *Action : Actions) {
940	// Action codes from docs are: 0 cleanup, 1 catch.
941	if (auto *CatchAction = dyn_cast<CatchHandler>(Action)) {
942	ActionArgs.push_back(ConstantInt::get(Int32Type, 1));
943	ActionArgs.push_back(CatchAction->getSelector());
944	// Find the frame escape index of the exception object alloca in the
945	// parent.
946	int FrameEscapeIdx = -1;
947	Value EHObj = const_cast<Value >(CatchAction->getExceptionVar());
948	if (EHObj && !isa<ConstantPointerNull>(EHObj)) {
949	auto I = FrameVarInfo.find(EHObj);
950	assert(I != FrameVarInfo.end() &&((I != FrameVarInfo.end() && "failed to map llvm.eh.begincatch var" ) ? static_cast<void> (0) : __assert_fail ("I != FrameVarInfo.end() && \"failed to map llvm.eh.begincatch var\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 951, __PRETTY_FUNCTION__))
951	"failed to map llvm.eh.begincatch var")((I != FrameVarInfo.end() && "failed to map llvm.eh.begincatch var" ) ? static_cast<void> (0) : __assert_fail ("I != FrameVarInfo.end() && \"failed to map llvm.eh.begincatch var\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 951, __PRETTY_FUNCTION__));
952	FrameEscapeIdx = std::distance(FrameVarInfo.begin(), I);
953	}
954	ActionArgs.push_back(ConstantInt::get(Int32Type, FrameEscapeIdx));
955	} else {
956	ActionArgs.push_back(ConstantInt::get(Int32Type, 0));
957	}
958	ActionArgs.push_back(Action->getHandlerBlockOrFunc());
959	}
960	CallInst *Recover =
961	CallInst::Create(ActionIntrin, ActionArgs, "recover", LPadBB);
962
963	SetVector<BasicBlock *> ReturnTargets;
964	for (ActionHandler *Action : Actions) {
965	if (auto *CatchAction = dyn_cast<CatchHandler>(Action)) {
966	const auto &CatchTargets = CatchAction->getReturnTargets();
967	ReturnTargets.insert(CatchTargets.begin(), CatchTargets.end());
968	}
969	}
970	IndirectBrInst *Branch =
971	IndirectBrInst::Create(Recover, ReturnTargets.size(), LPadBB);
972	for (BasicBlock *Target : ReturnTargets)
973	Branch->addDestination(Target);
974
975	if (!isAsynchronousEHPersonality(Personality)) {
976	// C++ EH must repopulate the targets later to handle the case of
977	// targets that are reached indirectly through nested landing pads.
978	LPadImpls.push_back(std::make_pair(Recover, Branch));
979	}
980
981	} // End for each landingpad
982
983	// If nothing got outlined, there is no more processing to be done.
984	if (!HandlersOutlined)
985	return false;
986
987	// Replace any nested landing pad stubs with the correct action handler.
988	// This must be done before we remove unreachable blocks because it
989	// cleans up references to outlined blocks that will be deleted.
990	for (auto &LPadPair : NestedLPtoOriginalLP)
991	completeNestedLandingPad(&F, LPadPair.first, LPadPair.second, FrameVarInfo);
992	NestedLPtoOriginalLP.clear();
993
994	// Update the indirectbr instructions' target lists if necessary.
995	SetVector<BasicBlock*> CheckedTargets;
996	SmallVector<std::unique_ptr<ActionHandler>, 4> ActionList;
997	for (auto &LPadImplPair : LPadImpls) {
998	IntrinsicInst *Recover = cast<IntrinsicInst>(LPadImplPair.first);
999	IndirectBrInst *Branch = LPadImplPair.second;
1000
1001	// Get a list of handlers called by
1002	parseEHActions(Recover, ActionList);
1003
1004	// Add an indirect branch listing possible successors of the catch handlers.
1005	SetVector<BasicBlock *> ReturnTargets;
1006	for (const auto &Action : ActionList) {
1007	if (auto *CA = dyn_cast<CatchHandler>(Action.get())) {
1008	Function *Handler = cast<Function>(CA->getHandlerBlockOrFunc());
1009	getPossibleReturnTargets(&F, Handler, ReturnTargets);
1010	}
1011	}
1012	ActionList.clear();
1013	// Clear any targets we already knew about.
1014	for (unsigned int I = 0, E = Branch->getNumDestinations(); I < E; ++I) {
1015	BasicBlock *KnownTarget = Branch->getDestination(I);
1016	if (ReturnTargets.count(KnownTarget))
1017	ReturnTargets.remove(KnownTarget);
1018	}
1019	for (BasicBlock *Target : ReturnTargets) {
1020	Branch->addDestination(Target);
1021	// The target may be a block that we excepted to get pruned.
1022	// If it is, it may contain a call to llvm.eh.endcatch.
1023	if (CheckedTargets.insert(Target)) {
1024	// Earlier preparations guarantee that all calls to llvm.eh.endcatch
1025	// will be followed by an unconditional branch.
1026	auto *Br = dyn_cast<BranchInst>(Target->getTerminator());
1027	if (Br && Br->isUnconditional() &&
1028	Br != Target->getFirstNonPHIOrDbgOrLifetime()) {
1029	Instruction *Prev = Br->getPrevNode();
1030	if (match(cast<Value>(Prev), m_Intrinsic<Intrinsic::eh_endcatch>()))
1031	Prev->eraseFromParent();
1032	}
1033	}
1034	}
1035	}
1036	LPadImpls.clear();
1037
1038	F.addFnAttr("wineh-parent", F.getName());
1039
1040	// Delete any blocks that were only used by handlers that were outlined above.
1041	removeUnreachableBlocks(F);
1042
1043	BasicBlock *Entry = &F.getEntryBlock();
1044	IRBuilder<> Builder(F.getParent()->getContext());
1045	Builder.SetInsertPoint(Entry->getFirstInsertionPt());
1046
1047	Function *FrameEscapeFn =
1048	Intrinsic::getDeclaration(M, Intrinsic::localescape);
1049	Function *RecoverFrameFn =
1050	Intrinsic::getDeclaration(M, Intrinsic::localrecover);
1051	SmallVector<Value *, 8> AllocasToEscape;
1052
1053	// Scan the entry block for an existing call to llvm.localescape. We need to
1054	// keep escaping those objects.
1055	for (Instruction &I : F.front()) {
1056	auto *II = dyn_cast<IntrinsicInst>(&I);
1057	if (II && II->getIntrinsicID() == Intrinsic::localescape) {
1058	auto Args = II->arg_operands();
1059	AllocasToEscape.append(Args.begin(), Args.end());
1060	II->eraseFromParent();
1061	break;
1062	}
1063	}
1064
1065	// Finally, replace all of the temporary allocas for frame variables used in
1066	// the outlined handlers with calls to llvm.localrecover.
1067	for (auto &VarInfoEntry : FrameVarInfo) {
1068	Value *ParentVal = VarInfoEntry.first;
1069	TinyPtrVector<AllocaInst *> &Allocas = VarInfoEntry.second;
1070	AllocaInst *ParentAlloca = cast<AllocaInst>(ParentVal);
1071
1072	// FIXME: We should try to sink unescaped allocas from the parent frame into
1073	// the child frame. If the alloca is escaped, we have to use the lifetime
1074	// markers to ensure that the alloca is only live within the child frame.
1075
1076	// Add this alloca to the list of things to escape.
1077	AllocasToEscape.push_back(ParentAlloca);
1078
1079	// Next replace all outlined allocas that are mapped to it.
1080	for (AllocaInst *TempAlloca : Allocas) {
1081	if (TempAlloca == getCatchObjectSentinel())
1082	continue; // Skip catch parameter sentinels.
1083	Function *HandlerFn = TempAlloca->getParent()->getParent();
1084	llvm::Value *FP = HandlerToParentFP[HandlerFn];
1085	assert(FP)((FP) ? static_cast<void> (0) : __assert_fail ("FP", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1085, __PRETTY_FUNCTION__));
1086
1087	// FIXME: Sink this localrecover into the blocks where it is used.
1088	Builder.SetInsertPoint(TempAlloca);
1089	Builder.SetCurrentDebugLocation(TempAlloca->getDebugLoc());
1090	Value *RecoverArgs[] = {
1091	Builder.CreateBitCast(&F, Int8PtrType, ""), FP,
1092	llvm::ConstantInt::get(Int32Type, AllocasToEscape.size() - 1)};
1093	Instruction *RecoveredAlloca =
1094	Builder.CreateCall(RecoverFrameFn, RecoverArgs);
1095
1096	// Add a pointer bitcast if the alloca wasn't an i8.
1097	if (RecoveredAlloca->getType() != TempAlloca->getType()) {
1098	RecoveredAlloca->setName(Twine(TempAlloca->getName()) + ".i8");
1099	RecoveredAlloca = cast<Instruction>(
1100	Builder.CreateBitCast(RecoveredAlloca, TempAlloca->getType()));
1101	}
1102	TempAlloca->replaceAllUsesWith(RecoveredAlloca);
1103	TempAlloca->removeFromParent();
1104	RecoveredAlloca->takeName(TempAlloca);
1105	delete TempAlloca;
1106	}
1107	} // End for each FrameVarInfo entry.
1108
1109	// Insert 'call void (...)* @llvm.localescape(...)' at the end of the entry
1110	// block.
1111	Builder.SetInsertPoint(&F.getEntryBlock().back());
1112	Builder.CreateCall(FrameEscapeFn, AllocasToEscape);
1113
1114	if (SEHExceptionCodeSlot) {
1115	if (isAllocaPromotable(SEHExceptionCodeSlot)) {
1116	SmallPtrSet<BasicBlock *, 4> UserBlocks;
1117	for (User *U : SEHExceptionCodeSlot->users()) {
1118	if (auto *Inst = dyn_cast<Instruction>(U))
1119	UserBlocks.insert(Inst->getParent());
1120	}
1121	PromoteMemToReg(SEHExceptionCodeSlot, *DT);
1122	// After the promotion, kill off dead instructions.
1123	for (BasicBlock *BB : UserBlocks)
1124	SimplifyInstructionsInBlock(BB, LibInfo);
1125	}
1126	}
1127
1128	// Clean up the handler action maps we created for this function
1129	DeleteContainerSeconds(CatchHandlerMap);
1130	CatchHandlerMap.clear();
1131	DeleteContainerSeconds(CleanupHandlerMap);
1132	CleanupHandlerMap.clear();
1133	HandlerToParentFP.clear();
1134	DT = nullptr;
1135	LibInfo = nullptr;
1136	SEHExceptionCodeSlot = nullptr;
1137	EHBlocks.clear();
1138	NormalBlocks.clear();
1139	EHReturnBlocks.clear();
1140
1141	return HandlersOutlined;
1142	}
1143
1144	void WinEHPrepare::promoteLandingPadValues(LandingPadInst *LPad) {
1145	// If the return values of the landing pad instruction are extracted and
1146	// stored to memory, we want to promote the store locations to reg values.
1147	SmallVector<AllocaInst *, 2> EHAllocas;
1148
1149	// The landingpad instruction returns an aggregate value. Typically, its
1150	// value will be passed to a pair of extract value instructions and the
1151	// results of those extracts are often passed to store instructions.
1152	// In unoptimized code the stored value will often be loaded and then stored
1153	// again.
1154	for (auto *U : LPad->users()) {
1155	ExtractValueInst *Extract = dyn_cast<ExtractValueInst>(U);
1156	if (!Extract)
1157	continue;
1158
1159	for (auto *EU : Extract->users()) {
1160	if (auto *Store = dyn_cast<StoreInst>(EU)) {
1161	auto *AV = cast<AllocaInst>(Store->getPointerOperand());
1162	EHAllocas.push_back(AV);
1163	}
1164	}
1165	}
1166
1167	// We can't do this without a dominator tree.
1168	assert(DT)((DT) ? static_cast<void> (0) : __assert_fail ("DT", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1168, __PRETTY_FUNCTION__));
1169
1170	if (!EHAllocas.empty()) {
1171	PromoteMemToReg(EHAllocas, *DT);
1172	EHAllocas.clear();
1173	}
1174
1175	// After promotion, some extracts may be trivially dead. Remove them.
1176	SmallVector<Value *, 4> Users(LPad->user_begin(), LPad->user_end());
1177	for (auto *U : Users)
1178	RecursivelyDeleteTriviallyDeadInstructions(U);
1179	}
1180
1181	void WinEHPrepare::getPossibleReturnTargets(Function *ParentF,
1182	Function *HandlerF,
1183	SetVector<BasicBlock*> &Targets) {
1184	for (BasicBlock &BB : *HandlerF) {
1185	// If the handler contains landing pads, check for any
1186	// handlers that may return directly to a block in the
1187	// parent function.
1188	if (auto *LPI = BB.getLandingPadInst()) {
1189	IntrinsicInst *Recover = cast<IntrinsicInst>(LPI->getNextNode());
1190	SmallVector<std::unique_ptr<ActionHandler>, 4> ActionList;
1191	parseEHActions(Recover, ActionList);
1192	for (const auto &Action : ActionList) {
1193	if (auto *CH = dyn_cast<CatchHandler>(Action.get())) {
1194	Function *NestedF = cast<Function>(CH->getHandlerBlockOrFunc());
1195	getPossibleReturnTargets(ParentF, NestedF, Targets);
1196	}
1197	}
1198	}
1199
1200	auto *Ret = dyn_cast<ReturnInst>(BB.getTerminator());
1201	if (!Ret)
1202	continue;
1203
1204	// Handler functions must always return a block address.
1205	BlockAddress *BA = cast<BlockAddress>(Ret->getReturnValue());
1206
1207	// If this is the handler for a nested landing pad, the
1208	// return address may have been remapped to a block in the
1209	// parent handler. We're not interested in those.
1210	if (BA->getFunction() != ParentF)
1211	continue;
1212
1213	Targets.insert(BA->getBasicBlock());
1214	}
1215	}
1216
1217	void WinEHPrepare::completeNestedLandingPad(Function *ParentFn,
1218	LandingPadInst *OutlinedLPad,
1219	const LandingPadInst *OriginalLPad,
1220	FrameVarInfoMap &FrameVarInfo) {
1221	// Get the nested block and erase the unreachable instruction that was
1222	// temporarily inserted as its terminator.
1223	LLVMContext &Context = ParentFn->getContext();
1224	BasicBlock *OutlinedBB = OutlinedLPad->getParent();
1225	// If the nested landing pad was outlined before the landing pad that enclosed
1226	// it, it will already be in outlined form. In that case, we just need to see
1227	// if the returns and the enclosing branch instruction need to be updated.
1228	IndirectBrInst *Branch =
1229	dyn_cast<IndirectBrInst>(OutlinedBB->getTerminator());
1230	if (!Branch) {
1231	// If the landing pad wasn't in outlined form, it should be a stub with
1232	// an unreachable terminator.
1233	assert(isa<UnreachableInst>(OutlinedBB->getTerminator()))((isa<UnreachableInst>(OutlinedBB->getTerminator())) ? static_cast<void> (0) : __assert_fail ("isa<UnreachableInst>(OutlinedBB->getTerminator())" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1233, __PRETTY_FUNCTION__));
1234	OutlinedBB->getTerminator()->eraseFromParent();
1235	// That should leave OutlinedLPad as the last instruction in its block.
1236	assert(&OutlinedBB->back() == OutlinedLPad)((&OutlinedBB->back() == OutlinedLPad) ? static_cast< void> (0) : __assert_fail ("&OutlinedBB->back() == OutlinedLPad" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1236, __PRETTY_FUNCTION__));
1237	}
1238
1239	// The original landing pad will have already had its action intrinsic
1240	// built by the outlining loop. We need to clone that into the outlined
1241	// location. It may also be necessary to add references to the exception
1242	// variables to the outlined handler in which this landing pad is nested
1243	// and remap return instructions in the nested handlers that should return
1244	// to an address in the outlined handler.
1245	Function *OutlinedHandlerFn = OutlinedBB->getParent();
1246	BasicBlock::const_iterator II = OriginalLPad;
1247	++II;
1248	// The instruction after the landing pad should now be a call to eh.actions.
1249	const Instruction *Recover = II;
1250	const IntrinsicInst *EHActions = cast<IntrinsicInst>(Recover);
1251
1252	// Remap the return target in the nested handler.
1253	SmallVector<BlockAddress *, 4> ActionTargets;
1254	SmallVector<std::unique_ptr<ActionHandler>, 4> ActionList;
1255	parseEHActions(EHActions, ActionList);
1256	for (const auto &Action : ActionList) {
1257	auto *Catch = dyn_cast<CatchHandler>(Action.get());
1258	if (!Catch)
1259	continue;
1260	// The dyn_cast to function here selects C++ catch handlers and skips
1261	// SEH catch handlers.
1262	auto *Handler = dyn_cast<Function>(Catch->getHandlerBlockOrFunc());
1263	if (!Handler)
1264	continue;
1265	// Visit all the return instructions, looking for places that return
1266	// to a location within OutlinedHandlerFn.
1267	for (BasicBlock &NestedHandlerBB : *Handler) {
1268	auto *Ret = dyn_cast<ReturnInst>(NestedHandlerBB.getTerminator());
1269	if (!Ret)
1270	continue;
1271
1272	// Handler functions must always return a block address.
1273	BlockAddress *BA = cast<BlockAddress>(Ret->getReturnValue());
1274	// The original target will have been in the main parent function,
1275	// but if it is the address of a block that has been outlined, it
1276	// should be a block that was outlined into OutlinedHandlerFn.
1277	assert(BA->getFunction() == ParentFn)((BA->getFunction() == ParentFn) ? static_cast<void> (0) : __assert_fail ("BA->getFunction() == ParentFn", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1277, __PRETTY_FUNCTION__));
1278
1279	// Ignore targets that aren't part of an outlined handler function.
1280	if (!LPadTargetBlocks.count(BA->getBasicBlock()))
1281	continue;
1282
1283	// If the return value is the address ofF a block that we
1284	// previously outlined into the parent handler function, replace
1285	// the return instruction and add the mapped target to the list
1286	// of possible return addresses.
1287	BasicBlock *MappedBB = LPadTargetBlocks[BA->getBasicBlock()];
1288	assert(MappedBB->getParent() == OutlinedHandlerFn)((MappedBB->getParent() == OutlinedHandlerFn) ? static_cast <void> (0) : __assert_fail ("MappedBB->getParent() == OutlinedHandlerFn" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1288, __PRETTY_FUNCTION__));
1289	BlockAddress *NewBA = BlockAddress::get(OutlinedHandlerFn, MappedBB);
1290	Ret->eraseFromParent();
1291	ReturnInst::Create(Context, NewBA, &NestedHandlerBB);
1292	ActionTargets.push_back(NewBA);
1293	}
1294	}
1295	ActionList.clear();
1296
1297	if (Branch) {
1298	// If the landing pad was already in outlined form, just update its targets.
1299	for (unsigned int I = Branch->getNumDestinations(); I > 0; --I)
1300	Branch->removeDestination(I);
1301	// Add the previously collected action targets.
1302	for (auto *Target : ActionTargets)
1303	Branch->addDestination(Target->getBasicBlock());
1304	} else {
1305	// If the landing pad was previously stubbed out, fill in its outlined form.
1306	IntrinsicInst *NewEHActions = cast<IntrinsicInst>(EHActions->clone());
1307	OutlinedBB->getInstList().push_back(NewEHActions);
1308
1309	// Insert an indirect branch into the outlined landing pad BB.
1310	IndirectBrInst *IBr = IndirectBrInst::Create(NewEHActions, 0, OutlinedBB);
1311	// Add the previously collected action targets.
1312	for (auto *Target : ActionTargets)
1313	IBr->addDestination(Target->getBasicBlock());
1314	}
1315	}
1316
1317	// This function examines a block to determine whether the block ends with a
1318	// conditional branch to a catch handler based on a selector comparison.
1319	// This function is used both by the WinEHPrepare::findSelectorComparison() and
1320	// WinEHCleanupDirector::handleTypeIdFor().
1321	static bool isSelectorDispatch(BasicBlock BB, BasicBlock &CatchHandler,
1322	Constant &Selector, BasicBlock &NextBB) {
1323	ICmpInst::Predicate Pred;
1324	BasicBlock TBB, FBB;
1325	Value LHS, RHS;
1326
1327	if (!match(BB->getTerminator(),
1328	m_Br(m_ICmp(Pred, m_Value(LHS), m_Value(RHS)), TBB, FBB)))
1329	return false;
1330
1331	if (!match(LHS,
1332	m_Intrinsic<Intrinsic::eh_typeid_for>(m_Constant(Selector))) &&
1333	!match(RHS, m_Intrinsic<Intrinsic::eh_typeid_for>(m_Constant(Selector))))
1334	return false;
1335
1336	if (Pred == CmpInst::ICMP_EQ) {
1337	CatchHandler = TBB;
1338	NextBB = FBB;
1339	return true;
1340	}
1341
1342	if (Pred == CmpInst::ICMP_NE) {
1343	CatchHandler = FBB;
1344	NextBB = TBB;
1345	return true;
1346	}
1347
1348	return false;
1349	}
1350
1351	static bool isCatchBlock(BasicBlock *BB) {
1352	for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
1353	II != IE; ++II) {
1354	if (match(cast<Value>(II), m_Intrinsic<Intrinsic::eh_begincatch>()))
1355	return true;
1356	}
1357	return false;
1358	}
1359
1360	static BasicBlock createStubLandingPad(Function Handler) {
1361	// FIXME: Finish this!
1362	LLVMContext &Context = Handler->getContext();
1363	BasicBlock *StubBB = BasicBlock::Create(Context, "stub");
1364	Handler->getBasicBlockList().push_back(StubBB);
1365	IRBuilder<> Builder(StubBB);
1366	LandingPadInst *LPad = Builder.CreateLandingPad(
1367	llvm::StructType::get(Type::getInt8PtrTy(Context),
1368	Type::getInt32Ty(Context), nullptr),
1369	0);
1370	// Insert a call to llvm.eh.actions so that we don't try to outline this lpad.
1371	Function *ActionIntrin =
1372	Intrinsic::getDeclaration(Handler->getParent(), Intrinsic::eh_actions);
1373	Builder.CreateCall(ActionIntrin, {}, "recover");
1374	LPad->setCleanup(true);
1375	Builder.CreateUnreachable();
1376	return StubBB;
1377	}
1378
1379	// Cycles through the blocks in an outlined handler function looking for an
1380	// invoke instruction and inserts an invoke of llvm.donothing with an empty
1381	// landing pad if none is found. The code that generates the .xdata tables for
1382	// the handler needs at least one landing pad to identify the parent function's
1383	// personality.
1384	void WinEHPrepare::addStubInvokeToHandlerIfNeeded(Function *Handler) {
1385	ReturnInst *Ret = nullptr;
1386	UnreachableInst *Unreached = nullptr;
1387	for (BasicBlock &BB : *Handler) {
1388	TerminatorInst *Terminator = BB.getTerminator();
1389	// If we find an invoke, there is nothing to be done.
1390	auto *II = dyn_cast<InvokeInst>(Terminator);
1391	if (II)
1392	return;
1393	// If we've already recorded a return instruction, keep looking for invokes.
1394	if (!Ret)
1395	Ret = dyn_cast<ReturnInst>(Terminator);
1396	// If we haven't recorded an unreachable instruction, try this terminator.
1397	if (!Unreached)
1398	Unreached = dyn_cast<UnreachableInst>(Terminator);
1399	}
1400
1401	// If we got this far, the handler contains no invokes. We should have seen
1402	// at least one return or unreachable instruction. We'll insert an invoke of
1403	// llvm.donothing ahead of that instruction.
1404	assert(Ret \|\| Unreached)((Ret \|\| Unreached) ? static_cast<void> (0) : __assert_fail ("Ret \|\| Unreached", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1404, __PRETTY_FUNCTION__));
1405	TerminatorInst *Term;
1406	if (Ret)
1407	Term = Ret;
1408	else
1409	Term = Unreached;
1410	BasicBlock *OldRetBB = Term->getParent();
1411	BasicBlock *NewRetBB = SplitBlock(OldRetBB, Term, DT);
1412	// SplitBlock adds an unconditional branch instruction at the end of the
1413	// parent block. We want to replace that with an invoke call, so we can
1414	// erase it now.
1415	OldRetBB->getTerminator()->eraseFromParent();
1416	BasicBlock *StubLandingPad = createStubLandingPad(Handler);
1417	Function *F =
1418	Intrinsic::getDeclaration(Handler->getParent(), Intrinsic::donothing);
1419	InvokeInst::Create(F, NewRetBB, StubLandingPad, None, "", OldRetBB);
1420	}
1421
1422	// FIXME: Consider sinking this into lib/Target/X86 somehow. TargetLowering
1423	// usually doesn't build LLVM IR, so that's probably the wrong place.
1424	Function WinEHPrepare::createHandlerFunc(Function ParentFn, Type *RetTy,
1425	const Twine &Name, Module *M,
1426	Value *&ParentFP) {
1427	// x64 uses a two-argument prototype where the parent FP is the second
1428	// argument. x86 uses no arguments, just the incoming EBP value.
1429	LLVMContext &Context = M->getContext();
1430	Type *Int8PtrType = Type::getInt8PtrTy(Context);
1431	FunctionType *FnType;
1432	if (TheTriple.getArch() == Triple::x86_64) {
1433	Type *ArgTys[2] = {Int8PtrType, Int8PtrType};
1434	FnType = FunctionType::get(RetTy, ArgTys, false);
1435	} else {
1436	FnType = FunctionType::get(RetTy, None, false);
1437	}
1438
1439	Function *Handler =
1440	Function::Create(FnType, GlobalVariable::InternalLinkage, Name, M);
1441	BasicBlock *Entry = BasicBlock::Create(Context, "entry");
1442	Handler->getBasicBlockList().push_front(Entry);
1443	if (TheTriple.getArch() == Triple::x86_64) {
1444	ParentFP = &(Handler->getArgumentList().back());
1445	} else {
1446	assert(M)((M) ? static_cast<void> (0) : __assert_fail ("M", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1446, __PRETTY_FUNCTION__));
1447	Function *FrameAddressFn =
1448	Intrinsic::getDeclaration(M, Intrinsic::frameaddress);
1449	Function *RecoverFPFn =
1450	Intrinsic::getDeclaration(M, Intrinsic::x86_seh_recoverfp);
1451	IRBuilder<> Builder(&Handler->getEntryBlock());
1452	Value *EBP =
1453	Builder.CreateCall(FrameAddressFn, {Builder.getInt32(1)}, "ebp");
1454	Value *ParentI8Fn = Builder.CreateBitCast(ParentFn, Int8PtrType);
1455	ParentFP = Builder.CreateCall(RecoverFPFn, {ParentI8Fn, EBP});
1456	}
1457	return Handler;
1458	}
1459
1460	bool WinEHPrepare::outlineHandler(ActionHandler Action, Function SrcFn,
1461	LandingPadInst LPad, BasicBlock StartBB,
1462	FrameVarInfoMap &VarInfo) {
1463	Module *M = SrcFn->getParent();
1464	LLVMContext &Context = M->getContext();
1465	Type *Int8PtrType = Type::getInt8PtrTy(Context);
1466
1467	// Create a new function to receive the handler contents.
1468	Value *ParentFP;
1469	Function *Handler;
1470	if (Action->getType() == Catch) {
1471	Handler = createHandlerFunc(SrcFn, Int8PtrType, SrcFn->getName() + ".catch", M,
1472	ParentFP);
1473	} else {
1474	Handler = createHandlerFunc(SrcFn, Type::getVoidTy(Context),
1475	SrcFn->getName() + ".cleanup", M, ParentFP);
1476	}
1477	Handler->setPersonalityFn(SrcFn->getPersonalityFn());
1478	HandlerToParentFP[Handler] = ParentFP;
1479	Handler->addFnAttr("wineh-parent", SrcFn->getName());
1480	BasicBlock *Entry = &Handler->getEntryBlock();
1481
1482	// Generate a standard prolog to setup the frame recovery structure.
1483	IRBuilder<> Builder(Context);
1484	Builder.SetInsertPoint(Entry);
1485	Builder.SetCurrentDebugLocation(LPad->getDebugLoc());
1486
1487	std::unique_ptr<WinEHCloningDirectorBase> Director;
1488
1489	ValueToValueMapTy VMap;
1490
1491	LandingPadMap &LPadMap = LPadMaps[LPad];
1492	if (!LPadMap.isInitialized())
1493	LPadMap.mapLandingPad(LPad);
1494	if (auto *CatchAction = dyn_cast<CatchHandler>(Action)) {
1495	Constant *Sel = CatchAction->getSelector();
1496	Director.reset(new WinEHCatchDirector(Handler, ParentFP, Sel, VarInfo,
1497	LPadMap, NestedLPtoOriginalLP, DT,
1498	EHBlocks));
1499	LPadMap.remapEHValues(VMap, UndefValue::get(Int8PtrType),
1500	ConstantInt::get(Type::getInt32Ty(Context), 1));
1501	} else {
1502	Director.reset(
1503	new WinEHCleanupDirector(Handler, ParentFP, VarInfo, LPadMap));
1504	LPadMap.remapEHValues(VMap, UndefValue::get(Int8PtrType),
1505	UndefValue::get(Type::getInt32Ty(Context)));
1506	}
1507
1508	SmallVector<ReturnInst *, 8> Returns;
1509	ClonedCodeInfo OutlinedFunctionInfo;
1510
1511	// If the start block contains PHI nodes, we need to map them.
1512	BasicBlock::iterator II = StartBB->begin();
1513	while (auto *PN = dyn_cast<PHINode>(II)) {
1514	bool Mapped = false;
1515	// Look for PHI values that we have already mapped (such as the selector).
1516	for (Value *Val : PN->incoming_values()) {
1517	if (VMap.count(Val)) {
1518	VMap[PN] = VMap[Val];
1519	Mapped = true;
1520	}
1521	}
1522	// If we didn't find a match for this value, map it as an undef.
1523	if (!Mapped) {
1524	VMap[PN] = UndefValue::get(PN->getType());
1525	}
1526	++II;
1527	}
1528
1529	// The landing pad value may be used by PHI nodes. It will ultimately be
1530	// eliminated, but we need it in the map for intermediate handling.
1531	VMap[LPad] = UndefValue::get(LPad->getType());
1532
1533	// Skip over PHIs and, if applicable, landingpad instructions.
1534	II = StartBB->getFirstInsertionPt();
1535
1536	CloneAndPruneIntoFromInst(Handler, SrcFn, II, VMap,
1537	/ModuleLevelChanges=/false, Returns, "",
1538	&OutlinedFunctionInfo, Director.get());
1539
1540	// Move all the instructions in the cloned "entry" block into our entry block.
1541	// Depending on how the parent function was laid out, the block that will
1542	// correspond to the outlined entry block may not be the first block in the
1543	// list. We can recognize it, however, as the cloned block which has no
1544	// predecessors. Any other block wouldn't have been cloned if it didn't
1545	// have a predecessor which was also cloned.
1546	Function::iterator ClonedIt = std::next(Function::iterator(Entry));
1547	while (!pred_empty(ClonedIt))
1548	++ClonedIt;
1549	BasicBlock *ClonedEntryBB = ClonedIt;
1550	assert(ClonedEntryBB)((ClonedEntryBB) ? static_cast<void> (0) : __assert_fail ("ClonedEntryBB", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1550, __PRETTY_FUNCTION__));
1551	Entry->getInstList().splice(Entry->end(), ClonedEntryBB->getInstList());
1552	ClonedEntryBB->eraseFromParent();
1553
1554	// Make sure we can identify the handler's personality later.
1555	addStubInvokeToHandlerIfNeeded(Handler);
1556
1557	if (auto *CatchAction = dyn_cast<CatchHandler>(Action)) {
1558	WinEHCatchDirector *CatchDirector =
1559	reinterpret_cast<WinEHCatchDirector *>(Director.get());
1560	CatchAction->setExceptionVar(CatchDirector->getExceptionVar());
1561	CatchAction->setReturnTargets(CatchDirector->getReturnTargets());
1562
1563	// Look for blocks that are not part of the landing pad that we just
1564	// outlined but terminate with a call to llvm.eh.endcatch and a
1565	// branch to a block that is in the handler we just outlined.
1566	// These blocks will be part of a nested landing pad that intends to
1567	// return to an address in this handler. This case is best handled
1568	// after both landing pads have been outlined, so for now we'll just
1569	// save the association of the blocks in LPadTargetBlocks. The
1570	// return instructions which are created from these branches will be
1571	// replaced after all landing pads have been outlined.
1572	for (const auto MapEntry : VMap) {
1573	// VMap maps all values and blocks that were just cloned, but dead
1574	// blocks which were pruned will map to nullptr.
1575	if (!isa<BasicBlock>(MapEntry.first) \|\| MapEntry.second == nullptr)
1576	continue;
1577	const BasicBlock *MappedBB = cast<BasicBlock>(MapEntry.first);
1578	for (auto Pred : predecessors(const_cast<BasicBlock >(MappedBB))) {
1579	auto *Branch = dyn_cast<BranchInst>(Pred->getTerminator());
1580	if (!Branch \|\| !Branch->isUnconditional() \|\| Pred->size() <= 1)
1581	continue;
1582	BasicBlock::iterator II = const_cast<BranchInst *>(Branch);
1583	--II;
1584	if (match(cast<Value>(II), m_Intrinsic<Intrinsic::eh_endcatch>())) {
1585	// This would indicate that a nested landing pad wants to return
1586	// to a block that is outlined into two different handlers.
1587	assert(!LPadTargetBlocks.count(MappedBB))((!LPadTargetBlocks.count(MappedBB)) ? static_cast<void> (0) : __assert_fail ("!LPadTargetBlocks.count(MappedBB)", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1587, __PRETTY_FUNCTION__));
1588	LPadTargetBlocks[MappedBB] = cast<BasicBlock>(MapEntry.second);
1589	}
1590	}
1591	}
1592	} // End if (CatchAction)
1593
1594	Action->setHandlerBlockOrFunc(Handler);
1595
1596	return true;
1597	}
1598
1599	/// This BB must end in a selector dispatch. All we need to do is pass the
1600	/// handler block to llvm.eh.actions and list it as a possible indirectbr
1601	/// target.
1602	void WinEHPrepare::processSEHCatchHandler(CatchHandler *CatchAction,
1603	BasicBlock *StartBB) {
1604	BasicBlock *HandlerBB;
1605	BasicBlock *NextBB;
1606	Constant *Selector;
1607	bool Res = isSelectorDispatch(StartBB, HandlerBB, Selector, NextBB);
1608	if (Res) {
1609	// If this was EH dispatch, this must be a conditional branch to the handler
1610	// block.
1611	// FIXME: Handle instructions in the dispatch block. Currently we drop them,
1612	// leading to crashes if some optimization hoists stuff here.
1613	assert(CatchAction->getSelector() && HandlerBB &&((CatchAction->getSelector() && HandlerBB && "expected catch EH dispatch") ? static_cast<void> (0) : __assert_fail ("CatchAction->getSelector() && HandlerBB && \"expected catch EH dispatch\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1614, __PRETTY_FUNCTION__))
1614	"expected catch EH dispatch")((CatchAction->getSelector() && HandlerBB && "expected catch EH dispatch") ? static_cast<void> (0) : __assert_fail ("CatchAction->getSelector() && HandlerBB && \"expected catch EH dispatch\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1614, __PRETTY_FUNCTION__));
1615	} else {
1616	// This must be a catch-all. Split the block after the landingpad.
1617	assert(CatchAction->getSelector()->isNullValue() && "expected catch-all")((CatchAction->getSelector()->isNullValue() && "expected catch-all" ) ? static_cast<void> (0) : __assert_fail ("CatchAction->getSelector()->isNullValue() && \"expected catch-all\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1617, __PRETTY_FUNCTION__));
1618	HandlerBB = SplitBlock(StartBB, StartBB->getFirstInsertionPt(), DT);
1619	}
1620	IRBuilder<> Builder(HandlerBB->getFirstInsertionPt());
1621	Function *EHCodeFn = Intrinsic::getDeclaration(
1622	StartBB->getParent()->getParent(), Intrinsic::eh_exceptioncode_old);
1623	Value *Code = Builder.CreateCall(EHCodeFn, {}, "sehcode");
1624	Code = Builder.CreateIntToPtr(Code, SEHExceptionCodeSlot->getAllocatedType());
1625	Builder.CreateStore(Code, SEHExceptionCodeSlot);
1626	CatchAction->setHandlerBlockOrFunc(BlockAddress::get(HandlerBB));
1627	TinyPtrVector<BasicBlock *> Targets(HandlerBB);
1628	CatchAction->setReturnTargets(Targets);
1629	}
1630
1631	void LandingPadMap::mapLandingPad(const LandingPadInst *LPad) {
1632	// Each instance of this class should only ever be used to map a single
1633	// landing pad.
1634	assert(OriginLPad == nullptr \|\| OriginLPad == LPad)((OriginLPad == nullptr \|\| OriginLPad == LPad) ? static_cast< void> (0) : __assert_fail ("OriginLPad == nullptr \|\| OriginLPad == LPad" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1634, __PRETTY_FUNCTION__));
1635
1636	// If the landing pad has already been mapped, there's nothing more to do.
1637	if (OriginLPad == LPad)
1638	return;
1639
1640	OriginLPad = LPad;
1641
1642	// The landingpad instruction returns an aggregate value. Typically, its
1643	// value will be passed to a pair of extract value instructions and the
1644	// results of those extracts will have been promoted to reg values before
1645	// this routine is called.
1646	for (auto *U : LPad->users()) {
1647	const ExtractValueInst *Extract = dyn_cast<ExtractValueInst>(U);
1648	if (!Extract)
1649	continue;
1650	assert(Extract->getNumIndices() == 1 &&((Extract->getNumIndices() == 1 && "Unexpected operation: extracting both landing pad values" ) ? static_cast<void> (0) : __assert_fail ("Extract->getNumIndices() == 1 && \"Unexpected operation: extracting both landing pad values\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1651, __PRETTY_FUNCTION__))
1651	"Unexpected operation: extracting both landing pad values")((Extract->getNumIndices() == 1 && "Unexpected operation: extracting both landing pad values" ) ? static_cast<void> (0) : __assert_fail ("Extract->getNumIndices() == 1 && \"Unexpected operation: extracting both landing pad values\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1651, __PRETTY_FUNCTION__));
1652	unsigned int Idx = *(Extract->idx_begin());
1653	assert((Idx == 0 \|\| Idx == 1) &&(((Idx == 0 \|\| Idx == 1) && "Unexpected operation: extracting an unknown landing pad element" ) ? static_cast<void> (0) : __assert_fail ("(Idx == 0 \|\| Idx == 1) && \"Unexpected operation: extracting an unknown landing pad element\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1654, __PRETTY_FUNCTION__))
1654	"Unexpected operation: extracting an unknown landing pad element")(((Idx == 0 \|\| Idx == 1) && "Unexpected operation: extracting an unknown landing pad element" ) ? static_cast<void> (0) : __assert_fail ("(Idx == 0 \|\| Idx == 1) && \"Unexpected operation: extracting an unknown landing pad element\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1654, __PRETTY_FUNCTION__));
1655	if (Idx == 0) {
1656	ExtractedEHPtrs.push_back(Extract);
1657	} else if (Idx == 1) {
1658	ExtractedSelectors.push_back(Extract);
1659	}
1660	}
1661	}
1662
1663	bool LandingPadMap::isOriginLandingPadBlock(const BasicBlock *BB) const {
1664	return BB->getLandingPadInst() == OriginLPad;
1665	}
1666
1667	bool LandingPadMap::isLandingPadSpecificInst(const Instruction *Inst) const {
1668	if (Inst == OriginLPad)
1669	return true;
1670	for (auto *Extract : ExtractedEHPtrs) {
1671	if (Inst == Extract)
1672	return true;
1673	}
1674	for (auto *Extract : ExtractedSelectors) {
1675	if (Inst == Extract)
1676	return true;
1677	}
1678	return false;
1679	}
1680
1681	void LandingPadMap::remapEHValues(ValueToValueMapTy &VMap, Value *EHPtrValue,
1682	Value *SelectorValue) const {
1683	// Remap all landing pad extract instructions to the specified values.
1684	for (auto *Extract : ExtractedEHPtrs)
1685	VMap[Extract] = EHPtrValue;
1686	for (auto *Extract : ExtractedSelectors)
1687	VMap[Extract] = SelectorValue;
1688	}
1689
1690	static bool isLocalAddressCall(const Value *V) {
1691	return match(const_cast<Value *>(V), m_Intrinsic<Intrinsic::localaddress>());
1692	}
1693
1694	CloningDirector::CloningAction WinEHCloningDirectorBase::handleInstruction(
1695	ValueToValueMapTy &VMap, const Instruction Inst, BasicBlock NewBB) {
1696	// If this is one of the boilerplate landing pad instructions, skip it.
1697	// The instruction will have already been remapped in VMap.
1698	if (LPadMap.isLandingPadSpecificInst(Inst))
1699	return CloningDirector::SkipInstruction;
1700
1701	// Nested landing pads that have not already been outlined will be cloned as
1702	// stubs, with just the landingpad instruction and an unreachable instruction.
1703	// When all landingpads have been outlined, we'll replace this with the
1704	// llvm.eh.actions call and indirect branch created when the landing pad was
1705	// outlined.
1706	if (auto *LPad = dyn_cast<LandingPadInst>(Inst)) {
1707	return handleLandingPad(VMap, LPad, NewBB);
1708	}
1709
1710	// Nested landing pads that have already been outlined will be cloned in their
1711	// outlined form, but we need to intercept the ibr instruction to filter out
1712	// targets that do not return to the handler we are outlining.
1713	if (auto *IBr = dyn_cast<IndirectBrInst>(Inst)) {
1714	return handleIndirectBr(VMap, IBr, NewBB);
1715	}
1716
1717	if (auto *Invoke = dyn_cast<InvokeInst>(Inst))
1718	return handleInvoke(VMap, Invoke, NewBB);
1719
1720	if (auto *Resume = dyn_cast<ResumeInst>(Inst))
1721	return handleResume(VMap, Resume, NewBB);
1722
1723	if (auto *Cmp = dyn_cast<CmpInst>(Inst))
1724	return handleCompare(VMap, Cmp, NewBB);
1725
1726	if (match(Inst, m_Intrinsic<Intrinsic::eh_begincatch>()))
1727	return handleBeginCatch(VMap, Inst, NewBB);
1728	if (match(Inst, m_Intrinsic<Intrinsic::eh_endcatch>()))
1729	return handleEndCatch(VMap, Inst, NewBB);
1730	if (match(Inst, m_Intrinsic<Intrinsic::eh_typeid_for>()))
1731	return handleTypeIdFor(VMap, Inst, NewBB);
1732
1733	// When outlining llvm.localaddress(), remap that to the second argument,
1734	// which is the FP of the parent.
1735	if (isLocalAddressCall(Inst)) {
1736	VMap[Inst] = ParentFP;
1737	return CloningDirector::SkipInstruction;
1738	}
1739
1740	// Continue with the default cloning behavior.
1741	return CloningDirector::CloneInstruction;
1742	}
1743
1744	CloningDirector::CloningAction WinEHCatchDirector::handleLandingPad(
1745	ValueToValueMapTy &VMap, const LandingPadInst LPad, BasicBlock NewBB) {
1746	// If the instruction after the landing pad is a call to llvm.eh.actions
1747	// the landing pad has already been outlined. In this case, we should
1748	// clone it because it may return to a block in the handler we are
1749	// outlining now that would otherwise be unreachable. The landing pads
1750	// are sorted before outlining begins to enable this case to work
1751	// properly.
1752	const Instruction *NextI = LPad->getNextNode();
1753	if (match(NextI, m_Intrinsic<Intrinsic::eh_actions>()))
1754	return CloningDirector::CloneInstruction;
1755
1756	// If the landing pad hasn't been outlined yet, the landing pad we are
1757	// outlining now does not dominate it and so it cannot return to a block
1758	// in this handler. In that case, we can just insert a stub landing
1759	// pad now and patch it up later.
1760	Instruction *NewInst = LPad->clone();
1761	if (LPad->hasName())
1762	NewInst->setName(LPad->getName());
1763	// Save this correlation for later processing.
1764	NestedLPtoOriginalLP[cast<LandingPadInst>(NewInst)] = LPad;
1765	VMap[LPad] = NewInst;
1766	BasicBlock::InstListType &InstList = NewBB->getInstList();
1767	InstList.push_back(NewInst);
1768	InstList.push_back(new UnreachableInst(NewBB->getContext()));
1769	return CloningDirector::StopCloningBB;
1770	}
1771
1772	CloningDirector::CloningAction WinEHCatchDirector::handleBeginCatch(
1773	ValueToValueMapTy &VMap, const Instruction Inst, BasicBlock NewBB) {
1774	// The argument to the call is some form of the first element of the
1775	// landingpad aggregate value, but that doesn't matter. It isn't used
1776	// here.
1777	// The second argument is an outparameter where the exception object will be
1778	// stored. Typically the exception object is a scalar, but it can be an
1779	// aggregate when catching by value.
1780	// FIXME: Leave something behind to indicate where the exception object lives
1781	// for this handler. Should it be part of llvm.eh.actions?
1782	assert(ExceptionObjectVar == nullptr && "Multiple calls to "((ExceptionObjectVar == nullptr && "Multiple calls to " "llvm.eh.begincatch found while " "outlining catch handler." ) ? static_cast<void> (0) : __assert_fail ("ExceptionObjectVar == nullptr && \"Multiple calls to \" \"llvm.eh.begincatch found while \" \"outlining catch handler.\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1784, __PRETTY_FUNCTION__))
1783	"llvm.eh.begincatch found while "((ExceptionObjectVar == nullptr && "Multiple calls to " "llvm.eh.begincatch found while " "outlining catch handler." ) ? static_cast<void> (0) : __assert_fail ("ExceptionObjectVar == nullptr && \"Multiple calls to \" \"llvm.eh.begincatch found while \" \"outlining catch handler.\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1784, __PRETTY_FUNCTION__))
1784	"outlining catch handler.")((ExceptionObjectVar == nullptr && "Multiple calls to " "llvm.eh.begincatch found while " "outlining catch handler." ) ? static_cast<void> (0) : __assert_fail ("ExceptionObjectVar == nullptr && \"Multiple calls to \" \"llvm.eh.begincatch found while \" \"outlining catch handler.\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1784, __PRETTY_FUNCTION__));
1785	ExceptionObjectVar = Inst->getOperand(1)->stripPointerCasts();
1786	if (isa<ConstantPointerNull>(ExceptionObjectVar))
1787	return CloningDirector::SkipInstruction;
1788	assert(cast<AllocaInst>(ExceptionObjectVar)->isStaticAlloca() &&((cast<AllocaInst>(ExceptionObjectVar)->isStaticAlloca () && "catch parameter is not static alloca") ? static_cast <void> (0) : __assert_fail ("cast<AllocaInst>(ExceptionObjectVar)->isStaticAlloca() && \"catch parameter is not static alloca\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1789, __PRETTY_FUNCTION__))
1789	"catch parameter is not static alloca")((cast<AllocaInst>(ExceptionObjectVar)->isStaticAlloca () && "catch parameter is not static alloca") ? static_cast <void> (0) : __assert_fail ("cast<AllocaInst>(ExceptionObjectVar)->isStaticAlloca() && \"catch parameter is not static alloca\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1789, __PRETTY_FUNCTION__));
1790	Materializer.escapeCatchObject(ExceptionObjectVar);
1791	return CloningDirector::SkipInstruction;
1792	}
1793
1794	CloningDirector::CloningAction
1795	WinEHCatchDirector::handleEndCatch(ValueToValueMapTy &VMap,
1796	const Instruction Inst, BasicBlock NewBB) {
1797	auto *IntrinCall = dyn_cast<IntrinsicInst>(Inst);
1798	// It might be interesting to track whether or not we are inside a catch
1799	// function, but that might make the algorithm more brittle than it needs
1800	// to be.
1801
1802	// The end catch call can occur in one of two places: either in a
1803	// landingpad block that is part of the catch handlers exception mechanism,
1804	// or at the end of the catch block. However, a catch-all handler may call
1805	// end catch from the original landing pad. If the call occurs in a nested
1806	// landing pad block, we must skip it and continue so that the landing pad
1807	// gets cloned.
1808	auto *ParentBB = IntrinCall->getParent();
1809	if (ParentBB->isLandingPad() && !LPadMap.isOriginLandingPadBlock(ParentBB))
1810	return CloningDirector::SkipInstruction;
1811
1812	// If an end catch occurs anywhere else we want to terminate the handler
1813	// with a return to the code that follows the endcatch call. If the
1814	// next instruction is not an unconditional branch, we need to split the
1815	// block to provide a clear target for the return instruction.
1816	BasicBlock *ContinueBB;
1817	auto Next = std::next(BasicBlock::const_iterator(IntrinCall));
1818	const BranchInst *Branch = dyn_cast<BranchInst>(Next);
1819	if (!Branch \|\| !Branch->isUnconditional()) {
1820	// We're interrupting the cloning process at this location, so the
1821	// const_cast we're doing here will not cause a problem.
1822	ContinueBB = SplitBlock(const_cast<BasicBlock *>(ParentBB),
1823	const_cast<Instruction *>(cast<Instruction>(Next)));
1824	} else {
1825	ContinueBB = Branch->getSuccessor(0);
1826	}
1827
1828	ReturnInst::Create(NewBB->getContext(), BlockAddress::get(ContinueBB), NewBB);
1829	ReturnTargets.push_back(ContinueBB);
1830
1831	// We just added a terminator to the cloned block.
1832	// Tell the caller to stop processing the current basic block so that
1833	// the branch instruction will be skipped.
1834	return CloningDirector::StopCloningBB;
1835	}
1836
1837	CloningDirector::CloningAction WinEHCatchDirector::handleTypeIdFor(
1838	ValueToValueMapTy &VMap, const Instruction Inst, BasicBlock NewBB) {
1839	auto *IntrinCall = dyn_cast<IntrinsicInst>(Inst);
1840	Value *Selector = IntrinCall->getArgOperand(0)->stripPointerCasts();
1841	// This causes a replacement that will collapse the landing pad CFG based
1842	// on the filter function we intend to match.
1843	if (Selector == CurrentSelector)
1844	VMap[Inst] = ConstantInt::get(SelectorIDType, 1);
1845	else
1846	VMap[Inst] = ConstantInt::get(SelectorIDType, 0);
1847	// Tell the caller not to clone this instruction.
1848	return CloningDirector::SkipInstruction;
1849	}
1850
1851	CloningDirector::CloningAction WinEHCatchDirector::handleIndirectBr(
1852	ValueToValueMapTy &VMap,
1853	const IndirectBrInst *IBr,
1854	BasicBlock *NewBB) {
1855	// If this indirect branch is not part of a landing pad block, just clone it.
1856	const BasicBlock *ParentBB = IBr->getParent();
1857	if (!ParentBB->isLandingPad())
1858	return CloningDirector::CloneInstruction;
1859
1860	// If it is part of a landing pad, we want to filter out target blocks
1861	// that are not part of the handler we are outlining.
1862	const LandingPadInst *LPad = ParentBB->getLandingPadInst();
1863
1864	// Save this correlation for later processing.
1865	NestedLPtoOriginalLP[cast<LandingPadInst>(VMap[LPad])] = LPad;
1866
1867	// We should only get here for landing pads that have already been outlined.
1868	assert(match(LPad->getNextNode(), m_Intrinsic<Intrinsic::eh_actions>()))((match(LPad->getNextNode(), m_Intrinsic<Intrinsic::eh_actions >())) ? static_cast<void> (0) : __assert_fail ("match(LPad->getNextNode(), m_Intrinsic<Intrinsic::eh_actions>())" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 1868, __PRETTY_FUNCTION__));
1869
1870	// Copy the indirectbr, but only include targets that were previously
1871	// identified as EH blocks and are dominated by the nested landing pad.
1872	SetVector<const BasicBlock *> ReturnTargets;
1873	for (int I = 0, E = IBr->getNumDestinations(); I < E; ++I) {
1874	auto *TargetBB = IBr->getDestination(I);
1875	if (EHBlocks.count(const_cast<BasicBlock*>(TargetBB)) &&
1876	DT->dominates(ParentBB, TargetBB)) {
1877	DEBUG(dbgs() << " Adding destination " << TargetBB->getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Adding destination " << TargetBB->getName() << "\n"; } } while (0);
1878	ReturnTargets.insert(TargetBB);
1879	}
1880	}
1881	IndirectBrInst *NewBranch =
1882	IndirectBrInst::Create(const_cast<Value *>(IBr->getAddress()),
1883	ReturnTargets.size(), NewBB);
1884	for (auto *Target : ReturnTargets)
1885	NewBranch->addDestination(const_cast<BasicBlock*>(Target));
1886
1887	// The operands and targets of the branch instruction are remapped later
1888	// because it is a terminator. Tell the cloning code to clone the
1889	// blocks we just added to the target list.
1890	return CloningDirector::CloneSuccessors;
1891	}
1892
1893	CloningDirector::CloningAction
1894	WinEHCatchDirector::handleInvoke(ValueToValueMapTy &VMap,
1895	const InvokeInst Invoke, BasicBlock NewBB) {
1896	return CloningDirector::CloneInstruction;
1897	}
1898
1899	CloningDirector::CloningAction
1900	WinEHCatchDirector::handleResume(ValueToValueMapTy &VMap,
1901	const ResumeInst Resume, BasicBlock NewBB) {
1902	// Resume instructions shouldn't be reachable from catch handlers.
1903	// We still need to handle it, but it will be pruned.
1904	BasicBlock::InstListType &InstList = NewBB->getInstList();
1905	InstList.push_back(new UnreachableInst(NewBB->getContext()));
1906	return CloningDirector::StopCloningBB;
1907	}
1908
1909	CloningDirector::CloningAction
1910	WinEHCatchDirector::handleCompare(ValueToValueMapTy &VMap,
1911	const CmpInst Compare, BasicBlock NewBB) {
1912	const IntrinsicInst *IntrinCall = nullptr;
1913	if (match(Compare->getOperand(0), m_Intrinsic<Intrinsic::eh_typeid_for>())) {
1914	IntrinCall = dyn_cast<IntrinsicInst>(Compare->getOperand(0));
1915	} else if (match(Compare->getOperand(1),
1916	m_Intrinsic<Intrinsic::eh_typeid_for>())) {
1917	IntrinCall = dyn_cast<IntrinsicInst>(Compare->getOperand(1));
1918	}
1919	if (IntrinCall) {
1920	Value *Selector = IntrinCall->getArgOperand(0)->stripPointerCasts();
1921	// This causes a replacement that will collapse the landing pad CFG based
1922	// on the filter function we intend to match.
1923	if (Selector == CurrentSelector->stripPointerCasts()) {
1924	VMap[Compare] = ConstantInt::get(SelectorIDType, 1);
1925	} else {
1926	VMap[Compare] = ConstantInt::get(SelectorIDType, 0);
1927	}
1928	return CloningDirector::SkipInstruction;
1929	}
1930	return CloningDirector::CloneInstruction;
1931	}
1932
1933	CloningDirector::CloningAction WinEHCleanupDirector::handleLandingPad(
1934	ValueToValueMapTy &VMap, const LandingPadInst LPad, BasicBlock NewBB) {
1935	// The MS runtime will terminate the process if an exception occurs in a
1936	// cleanup handler, so we shouldn't encounter landing pads in the actual
1937	// cleanup code, but they may appear in catch blocks. Depending on where
1938	// we started cloning we may see one, but it will get dropped during dead
1939	// block pruning.
1940	Instruction *NewInst = new UnreachableInst(NewBB->getContext());
1941	VMap[LPad] = NewInst;
1942	BasicBlock::InstListType &InstList = NewBB->getInstList();
1943	InstList.push_back(NewInst);
1944	return CloningDirector::StopCloningBB;
1945	}
1946
1947	CloningDirector::CloningAction WinEHCleanupDirector::handleBeginCatch(
1948	ValueToValueMapTy &VMap, const Instruction Inst, BasicBlock NewBB) {
1949	// Cleanup code may flow into catch blocks or the catch block may be part
1950	// of a branch that will be optimized away. We'll insert a return
1951	// instruction now, but it may be pruned before the cloning process is
1952	// complete.
1953	ReturnInst::Create(NewBB->getContext(), nullptr, NewBB);
1954	return CloningDirector::StopCloningBB;
1955	}
1956
1957	CloningDirector::CloningAction WinEHCleanupDirector::handleEndCatch(
1958	ValueToValueMapTy &VMap, const Instruction Inst, BasicBlock NewBB) {
1959	// Cleanup handlers nested within catch handlers may begin with a call to
1960	// eh.endcatch. We can just ignore that instruction.
1961	return CloningDirector::SkipInstruction;
1962	}
1963
1964	CloningDirector::CloningAction WinEHCleanupDirector::handleTypeIdFor(
1965	ValueToValueMapTy &VMap, const Instruction Inst, BasicBlock NewBB) {
1966	// If we encounter a selector comparison while cloning a cleanup handler,
1967	// we want to stop cloning immediately. Anything after the dispatch
1968	// will be outlined into a different handler.
1969	BasicBlock *CatchHandler;
1970	Constant *Selector;
1971	BasicBlock *NextBB;
1972	if (isSelectorDispatch(const_cast<BasicBlock *>(Inst->getParent()),
1973	CatchHandler, Selector, NextBB)) {
1974	ReturnInst::Create(NewBB->getContext(), nullptr, NewBB);
1975	return CloningDirector::StopCloningBB;
1976	}
1977	// If eg.typeid.for is called for any other reason, it can be ignored.
1978	VMap[Inst] = ConstantInt::get(SelectorIDType, 0);
1979	return CloningDirector::SkipInstruction;
1980	}
1981
1982	CloningDirector::CloningAction WinEHCleanupDirector::handleIndirectBr(
1983	ValueToValueMapTy &VMap,
1984	const IndirectBrInst *IBr,
1985	BasicBlock *NewBB) {
1986	// No special handling is required for cleanup cloning.
1987	return CloningDirector::CloneInstruction;
1988	}
1989
1990	CloningDirector::CloningAction WinEHCleanupDirector::handleInvoke(
1991	ValueToValueMapTy &VMap, const InvokeInst Invoke, BasicBlock NewBB) {
1992	// All invokes in cleanup handlers can be replaced with calls.
1993	SmallVector<Value *, 16> CallArgs(Invoke->op_begin(), Invoke->op_end() - 3);
1994	// Insert a normal call instruction...
1995	CallInst *NewCall =
1996	CallInst::Create(const_cast<Value *>(Invoke->getCalledValue()), CallArgs,
1997	Invoke->getName(), NewBB);
1998	NewCall->setCallingConv(Invoke->getCallingConv());
1999	NewCall->setAttributes(Invoke->getAttributes());
2000	NewCall->setDebugLoc(Invoke->getDebugLoc());
2001	VMap[Invoke] = NewCall;
2002
2003	// Remap the operands.
2004	llvm::RemapInstruction(NewCall, VMap, RF_None, nullptr, &Materializer);
2005
2006	// Insert an unconditional branch to the normal destination.
2007	BranchInst::Create(Invoke->getNormalDest(), NewBB);
2008
2009	// The unwind destination won't be cloned into the new function, so
2010	// we don't need to clean up its phi nodes.
2011
2012	// We just added a terminator to the cloned block.
2013	// Tell the caller to stop processing the current basic block.
2014	return CloningDirector::CloneSuccessors;
2015	}
2016
2017	CloningDirector::CloningAction WinEHCleanupDirector::handleResume(
2018	ValueToValueMapTy &VMap, const ResumeInst Resume, BasicBlock NewBB) {
2019	ReturnInst::Create(NewBB->getContext(), nullptr, NewBB);
2020
2021	// We just added a terminator to the cloned block.
2022	// Tell the caller to stop processing the current basic block so that
2023	// the branch instruction will be skipped.
2024	return CloningDirector::StopCloningBB;
2025	}
2026
2027	CloningDirector::CloningAction
2028	WinEHCleanupDirector::handleCompare(ValueToValueMapTy &VMap,
2029	const CmpInst Compare, BasicBlock NewBB) {
2030	if (match(Compare->getOperand(0), m_Intrinsic<Intrinsic::eh_typeid_for>()) \|\|
2031	match(Compare->getOperand(1), m_Intrinsic<Intrinsic::eh_typeid_for>())) {
2032	VMap[Compare] = ConstantInt::get(SelectorIDType, 1);
2033	return CloningDirector::SkipInstruction;
2034	}
2035	return CloningDirector::CloneInstruction;
2036	}
2037
2038	WinEHFrameVariableMaterializer::WinEHFrameVariableMaterializer(
2039	Function OutlinedFn, Value ParentFP, FrameVarInfoMap &FrameVarInfo)
2040	: FrameVarInfo(FrameVarInfo), Builder(OutlinedFn->getContext()) {
2041	BasicBlock *EntryBB = &OutlinedFn->getEntryBlock();
2042
2043	// New allocas should be inserted in the entry block, but after the parent FP
2044	// is established if it is an instruction.
2045	Instruction *InsertPoint = EntryBB->getFirstInsertionPt();
2046	if (auto *FPInst = dyn_cast<Instruction>(ParentFP))
2047	InsertPoint = FPInst->getNextNode();
2048	Builder.SetInsertPoint(EntryBB, InsertPoint);
2049	}
2050
2051	Value WinEHFrameVariableMaterializer::materializeValueFor(Value V) {
2052	// If we're asked to materialize a static alloca, we temporarily create an
2053	// alloca in the outlined function and add this to the FrameVarInfo map. When
2054	// all the outlining is complete, we'll replace these temporary allocas with
2055	// calls to llvm.localrecover.
2056	if (auto *AV = dyn_cast<AllocaInst>(V)) {
2057	assert(AV->isStaticAlloca() &&((AV->isStaticAlloca() && "cannot materialize un-demoted dynamic alloca" ) ? static_cast<void> (0) : __assert_fail ("AV->isStaticAlloca() && \"cannot materialize un-demoted dynamic alloca\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2058, __PRETTY_FUNCTION__))
2058	"cannot materialize un-demoted dynamic alloca")((AV->isStaticAlloca() && "cannot materialize un-demoted dynamic alloca" ) ? static_cast<void> (0) : __assert_fail ("AV->isStaticAlloca() && \"cannot materialize un-demoted dynamic alloca\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2058, __PRETTY_FUNCTION__));
2059	AllocaInst *NewAlloca = dyn_cast<AllocaInst>(AV->clone());
2060	Builder.Insert(NewAlloca, AV->getName());
2061	FrameVarInfo[AV].push_back(NewAlloca);
2062	return NewAlloca;
2063	}
2064
2065	if (isa<Instruction>(V) \|\| isa<Argument>(V)) {
2066	Function *Parent = isa<Instruction>(V)
2067	? cast<Instruction>(V)->getParent()->getParent()
2068	: cast<Argument>(V)->getParent();
2069	errs()
2070	<< "Failed to demote instruction used in exception handler of function "
2071	<< GlobalValue::getRealLinkageName(Parent->getName()) << ":\n";
2072	errs() << " " << *V << '\n';
2073	report_fatal_error("WinEHPrepare failed to demote instruction");
2074	}
2075
2076	// Don't materialize other values.
2077	return nullptr;
2078	}
2079
2080	void WinEHFrameVariableMaterializer::escapeCatchObject(Value *V) {
2081	// Catch parameter objects have to live in the parent frame. When we see a use
2082	// of a catch parameter, add a sentinel to the multimap to indicate that it's
2083	// used from another handler. This will prevent us from trying to sink the
2084	// alloca into the handler and ensure that the catch parameter is present in
2085	// the call to llvm.localescape.
2086	FrameVarInfo[V].push_back(getCatchObjectSentinel());
2087	}
2088
2089	// This function maps the catch and cleanup handlers that are reachable from the
2090	// specified landing pad. The landing pad sequence will have this basic shape:
2091	//
2092	// <cleanup handler>
2093	// <selector comparison>
2094	// <catch handler>
2095	// <cleanup handler>
2096	// <selector comparison>
2097	// <catch handler>
2098	// <cleanup handler>
2099	// ...
2100	//
2101	// Any of the cleanup slots may be absent. The cleanup slots may be occupied by
2102	// any arbitrary control flow, but all paths through the cleanup code must
2103	// eventually reach the next selector comparison and no path can skip to a
2104	// different selector comparisons, though some paths may terminate abnormally.
2105	// Therefore, we will use a depth first search from the start of any given
2106	// cleanup block and stop searching when we find the next selector comparison.
2107	//
2108	// If the landingpad instruction does not have a catch clause, we will assume
2109	// that any instructions other than selector comparisons and catch handlers can
2110	// be ignored. In practice, these will only be the boilerplate instructions.
2111	//
2112	// The catch handlers may also have any control structure, but we are only
2113	// interested in the start of the catch handlers, so we don't need to actually
2114	// follow the flow of the catch handlers. The start of the catch handlers can
2115	// be located from the compare instructions, but they can be skipped in the
2116	// flow by following the contrary branch.
2117	void WinEHPrepare::mapLandingPadBlocks(LandingPadInst *LPad,
2118	LandingPadActions &Actions) {
2119	unsigned int NumClauses = LPad->getNumClauses();
2120	unsigned int HandlersFound = 0;
2121	BasicBlock *BB = LPad->getParent();
2122
2123	DEBUG(dbgs() << "Mapping landing pad: " << BB->getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Mapping landing pad: " << BB->getName() << "\n"; } } while (0);
2124
2125	if (NumClauses == 0) {
2126	findCleanupHandlers(Actions, BB, nullptr);
2127	return;
2128	}
2129
2130	VisitedBlockSet VisitedBlocks;
2131
2132	while (HandlersFound != NumClauses) {
2133	BasicBlock *NextBB = nullptr;
2134
2135	// Skip over filter clauses.
2136	if (LPad->isFilter(HandlersFound)) {
2137	++HandlersFound;
2138	continue;
2139	}
2140
2141	// See if the clause we're looking for is a catch-all.
2142	// If so, the catch begins immediately.
2143	Constant *ExpectedSelector =
2144	LPad->getClause(HandlersFound)->stripPointerCasts();
2145	if (isa<ConstantPointerNull>(ExpectedSelector)) {
2146	// The catch all must occur last.
2147	assert(HandlersFound == NumClauses - 1)((HandlersFound == NumClauses - 1) ? static_cast<void> ( 0) : __assert_fail ("HandlersFound == NumClauses - 1", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2147, __PRETTY_FUNCTION__));
2148
2149	// There can be additional selector dispatches in the call chain that we
2150	// need to ignore.
2151	BasicBlock *CatchBlock = nullptr;
2152	Constant *Selector;
2153	while (BB && isSelectorDispatch(BB, CatchBlock, Selector, NextBB)) {
2154	DEBUG(dbgs() << " Found extra catch dispatch in block "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found extra catch dispatch in block " << CatchBlock->getName() << "\n"; } } while ( 0)
2155	<< CatchBlock->getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found extra catch dispatch in block " << CatchBlock->getName() << "\n"; } } while ( 0);
2156	BB = NextBB;
2157	}
2158
2159	// Add the catch handler to the action list.
2160	CatchHandler *Action = nullptr;
2161	if (CatchHandlerMap.count(BB) && CatchHandlerMap[BB] != nullptr) {
2162	// If the CatchHandlerMap already has an entry for this BB, re-use it.
2163	Action = CatchHandlerMap[BB];
2164	assert(Action->getSelector() == ExpectedSelector)((Action->getSelector() == ExpectedSelector) ? static_cast <void> (0) : __assert_fail ("Action->getSelector() == ExpectedSelector" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2164, __PRETTY_FUNCTION__));
2165	} else {
2166	// We don't expect a selector dispatch, but there may be a call to
2167	// llvm.eh.begincatch, which separates catch handling code from
2168	// cleanup code in the same control flow. This call looks for the
2169	// begincatch intrinsic.
2170	Action = findCatchHandler(BB, NextBB, VisitedBlocks);
2171	if (Action) {
2172	// For C++ EH, check if there is any interesting cleanup code before
2173	// we begin the catch. This is important because cleanups cannot
2174	// rethrow exceptions but code called from catches can. For SEH, it
2175	// isn't important if some finally code before a catch-all is executed
2176	// out of line or after recovering from the exception.
2177	if (Personality == EHPersonality::MSVC_CXX)
2178	findCleanupHandlers(Actions, BB, BB);
2179	} else {
2180	// If an action was not found, it means that the control flows
2181	// directly into the catch-all handler and there is no cleanup code.
2182	// That's an expected situation and we must create a catch action.
2183	// Since this is a catch-all handler, the selector won't actually
2184	// appear in the code anywhere. ExpectedSelector here is the constant
2185	// null ptr that we got from the landing pad instruction.
2186	Action = new CatchHandler(BB, ExpectedSelector, nullptr);
2187	CatchHandlerMap[BB] = Action;
2188	}
2189	}
2190	Actions.insertCatchHandler(Action);
2191	DEBUG(dbgs() << " Catch all handler at block " << BB->getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Catch all handler at block " << BB->getName() << "\n"; } } while (0);
2192	++HandlersFound;
2193
2194	// Once we reach a catch-all, don't expect to hit a resume instruction.
2195	BB = nullptr;
2196	break;
2197	}
2198
2199	CatchHandler *CatchAction = findCatchHandler(BB, NextBB, VisitedBlocks);
2200	assert(CatchAction)((CatchAction) ? static_cast<void> (0) : __assert_fail ( "CatchAction", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2200, __PRETTY_FUNCTION__));
2201
2202	// See if there is any interesting code executed before the dispatch.
2203	findCleanupHandlers(Actions, BB, CatchAction->getStartBlock());
2204
2205	// When the source program contains multiple nested try blocks the catch
2206	// handlers can get strung together in such a way that we can encounter
2207	// a dispatch for a selector that we've already had a handler for.
2208	if (CatchAction->getSelector()->stripPointerCasts() == ExpectedSelector) {
2209	++HandlersFound;
2210
2211	// Add the catch handler to the action list.
2212	DEBUG(dbgs() << " Found catch dispatch in block "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found catch dispatch in block " << CatchAction->getStartBlock()->getName() << "\n"; } } while (0)
2213	<< CatchAction->getStartBlock()->getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found catch dispatch in block " << CatchAction->getStartBlock()->getName() << "\n"; } } while (0);
2214	Actions.insertCatchHandler(CatchAction);
2215	} else {
2216	// Under some circumstances optimized IR will flow unconditionally into a
2217	// handler block without checking the selector. This can only happen if
2218	// the landing pad has a catch-all handler and the handler for the
2219	// preceding catch clause is identical to the catch-call handler
2220	// (typically an empty catch). In this case, the handler must be shared
2221	// by all remaining clauses.
2222	if (isa<ConstantPointerNull>(
2223	CatchAction->getSelector()->stripPointerCasts())) {
2224	DEBUG(dbgs() << " Applying early catch-all handler in block "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Applying early catch-all handler in block " << CatchAction->getStartBlock()->getName() << " to all remaining clauses.\n"; } } while (0)
2225	<< CatchAction->getStartBlock()->getName()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Applying early catch-all handler in block " << CatchAction->getStartBlock()->getName() << " to all remaining clauses.\n"; } } while (0)
2226	<< " to all remaining clauses.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Applying early catch-all handler in block " << CatchAction->getStartBlock()->getName() << " to all remaining clauses.\n"; } } while (0);
2227	Actions.insertCatchHandler(CatchAction);
2228	return;
2229	}
2230
2231	DEBUG(dbgs() << " Found extra catch dispatch in block "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found extra catch dispatch in block " << CatchAction->getStartBlock()->getName() << "\n"; } } while (0)
2232	<< CatchAction->getStartBlock()->getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found extra catch dispatch in block " << CatchAction->getStartBlock()->getName() << "\n"; } } while (0);
2233	}
2234
2235	// Move on to the block after the catch handler.
2236	BB = NextBB;
2237	}
2238
2239	// If we didn't wind up in a catch-all, see if there is any interesting code
2240	// executed before the resume.
2241	findCleanupHandlers(Actions, BB, BB);
2242
2243	// It's possible that some optimization moved code into a landingpad that
2244	// wasn't
2245	// previously being used for cleanup. If that happens, we need to execute
2246	// that
2247	// extra code from a cleanup handler.
2248	if (Actions.includesCleanup() && !LPad->isCleanup())
2249	LPad->setCleanup(true);
2250	}
2251
2252	// This function searches starting with the input block for the next
2253	// block that terminates with a branch whose condition is based on a selector
2254	// comparison. This may be the input block. See the mapLandingPadBlocks
2255	// comments for a discussion of control flow assumptions.
2256	//
2257	CatchHandler WinEHPrepare::findCatchHandler(BasicBlock BB,
2258	BasicBlock *&NextBB,
2259	VisitedBlockSet &VisitedBlocks) {
2260	// See if we've already found a catch handler use it.
2261	// Call count() first to avoid creating a null entry for blocks
2262	// we haven't seen before.
2263	if (CatchHandlerMap.count(BB) && CatchHandlerMap[BB] != nullptr) {
2264	CatchHandler *Action = cast<CatchHandler>(CatchHandlerMap[BB]);
2265	NextBB = Action->getNextBB();
2266	return Action;
2267	}
2268
2269	// VisitedBlocks applies only to the current search. We still
2270	// need to consider blocks that we've visited while mapping other
2271	// landing pads.
2272	VisitedBlocks.insert(BB);
2273
2274	BasicBlock *CatchBlock = nullptr;
2275	Constant *Selector = nullptr;
2276
2277	// If this is the first time we've visited this block from any landing pad
2278	// look to see if it is a selector dispatch block.
2279	if (!CatchHandlerMap.count(BB)) {
2280	if (isSelectorDispatch(BB, CatchBlock, Selector, NextBB)) {
2281	CatchHandler *Action = new CatchHandler(BB, Selector, NextBB);
2282	CatchHandlerMap[BB] = Action;
2283	return Action;
2284	}
2285	// If we encounter a block containing an llvm.eh.begincatch before we
2286	// find a selector dispatch block, the handler is assumed to be
2287	// reached unconditionally. This happens for catch-all blocks, but
2288	// it can also happen for other catch handlers that have been combined
2289	// with the catch-all handler during optimization.
2290	if (isCatchBlock(BB)) {
2291	PointerType *Int8PtrTy = Type::getInt8PtrTy(BB->getContext());
2292	Constant *NullSelector = ConstantPointerNull::get(Int8PtrTy);
2293	CatchHandler *Action = new CatchHandler(BB, NullSelector, nullptr);
2294	CatchHandlerMap[BB] = Action;
2295	return Action;
2296	}
2297	}
2298
2299	// Visit each successor, looking for the dispatch.
2300	// FIXME: We expect to find the dispatch quickly, so this will probably
2301	// work better as a breadth first search.
2302	for (BasicBlock *Succ : successors(BB)) {
2303	if (VisitedBlocks.count(Succ))
2304	continue;
2305
2306	CatchHandler *Action = findCatchHandler(Succ, NextBB, VisitedBlocks);
2307	if (Action)
2308	return Action;
2309	}
2310	return nullptr;
2311	}
2312
2313	// These are helper functions to combine repeated code from findCleanupHandlers.
2314	static void createCleanupHandler(LandingPadActions &Actions,
2315	CleanupHandlerMapTy &CleanupHandlerMap,
2316	BasicBlock *BB) {
2317	CleanupHandler *Action = new CleanupHandler(BB);
2318	CleanupHandlerMap[BB] = Action;
2319	Actions.insertCleanupHandler(Action);
2320	DEBUG(dbgs() << " Found cleanup code in block "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found cleanup code in block " << Action->getStartBlock()->getName() << "\n" ; } } while (0)
2321	<< Action->getStartBlock()->getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found cleanup code in block " << Action->getStartBlock()->getName() << "\n" ; } } while (0);
2322	}
2323
2324	static CallSite matchOutlinedFinallyCall(BasicBlock *BB,
2325	Instruction *MaybeCall) {
2326	// Look for finally blocks that Clang has already outlined for us.
2327	// %fp = call i8* @llvm.localaddress()
2328	// call void @"fin$parent"(iN 1, i8* %fp)
2329	if (isLocalAddressCall(MaybeCall) && MaybeCall != BB->getTerminator())
2330	MaybeCall = MaybeCall->getNextNode();
2331	CallSite FinallyCall(MaybeCall);
2332	if (!FinallyCall \|\| FinallyCall.arg_size() != 2)
2333	return CallSite();
2334	if (!match(FinallyCall.getArgument(0), m_SpecificInt(1)))
2335	return CallSite();
2336	if (!isLocalAddressCall(FinallyCall.getArgument(1)))
2337	return CallSite();
2338	return FinallyCall;
2339	}
2340
2341	static BasicBlock followSingleUnconditionalBranches(BasicBlock BB) {
2342	// Skip single ubr blocks.
2343	while (BB->getFirstNonPHIOrDbg() == BB->getTerminator()) {
2344	auto *Br = dyn_cast<BranchInst>(BB->getTerminator());
2345	if (Br && Br->isUnconditional())
2346	BB = Br->getSuccessor(0);
2347	else
2348	return BB;
2349	}
2350	return BB;
2351	}
2352
2353	// This function searches starting with the input block for the next block that
2354	// contains code that is not part of a catch handler and would not be eliminated
2355	// during handler outlining.
2356	//
2357	void WinEHPrepare::findCleanupHandlers(LandingPadActions &Actions,
2358	BasicBlock StartBB, BasicBlock EndBB) {
2359	// Here we will skip over the following:
2360	//
2361	// landing pad prolog:
2362	//
2363	// Unconditional branches
2364	//
2365	// Selector dispatch
2366	//
2367	// Resume pattern
2368	//
2369	// Anything else marks the start of an interesting block
2370
2371	BasicBlock *BB = StartBB;
2372	// Anything other than an unconditional branch will kick us out of this loop
2373	// one way or another.
2374	while (BB) {
2375	BB = followSingleUnconditionalBranches(BB);
2376	// If we've already scanned this block, don't scan it again. If it is
2377	// a cleanup block, there will be an action in the CleanupHandlerMap.
2378	// If we've scanned it and it is not a cleanup block, there will be a
2379	// nullptr in the CleanupHandlerMap. If we have not scanned it, there will
2380	// be no entry in the CleanupHandlerMap. We must call count() first to
2381	// avoid creating a null entry for blocks we haven't scanned.
2382	if (CleanupHandlerMap.count(BB)) {
2383	if (auto *Action = CleanupHandlerMap[BB]) {
2384	Actions.insertCleanupHandler(Action);
2385	DEBUG(dbgs() << " Found cleanup code in block "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found cleanup code in block " << Action->getStartBlock()->getName() << "\n" ; } } while (0)
2386	<< Action->getStartBlock()->getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found cleanup code in block " << Action->getStartBlock()->getName() << "\n" ; } } while (0);
2387	// FIXME: This cleanup might chain into another, and we need to discover
2388	// that.
2389	return;
2390	} else {
2391	// Here we handle the case where the cleanup handler map contains a
2392	// value for this block but the value is a nullptr. This means that
2393	// we have previously analyzed the block and determined that it did
2394	// not contain any cleanup code. Based on the earlier analysis, we
2395	// know the block must end in either an unconditional branch, a
2396	// resume or a conditional branch that is predicated on a comparison
2397	// with a selector. Either the resume or the selector dispatch
2398	// would terminate the search for cleanup code, so the unconditional
2399	// branch is the only case for which we might need to continue
2400	// searching.
2401	BasicBlock *SuccBB = followSingleUnconditionalBranches(BB);
2402	if (SuccBB == BB \|\| SuccBB == EndBB)
2403	return;
2404	BB = SuccBB;
2405	continue;
2406	}
2407	}
2408
2409	// Create an entry in the cleanup handler map for this block. Initially
2410	// we create an entry that says this isn't a cleanup block. If we find
2411	// cleanup code, the caller will replace this entry.
2412	CleanupHandlerMap[BB] = nullptr;
2413
2414	TerminatorInst *Terminator = BB->getTerminator();
2415
2416	// Landing pad blocks have extra instructions we need to accept.
2417	LandingPadMap *LPadMap = nullptr;
2418	if (BB->isLandingPad()) {
2419	LandingPadInst *LPad = BB->getLandingPadInst();
2420	LPadMap = &LPadMaps[LPad];
2421	if (!LPadMap->isInitialized())
2422	LPadMap->mapLandingPad(LPad);
2423	}
2424
2425	// Look for the bare resume pattern:
2426	// %lpad.val1 = insertvalue { i8, i32 } undef, i8 %exn, 0
2427	// %lpad.val2 = insertvalue { i8*, i32 } %lpad.val1, i32 %sel, 1
2428	// resume { i8*, i32 } %lpad.val2
2429	if (auto *Resume = dyn_cast<ResumeInst>(Terminator)) {
2430	InsertValueInst *Insert1 = nullptr;
2431	InsertValueInst *Insert2 = nullptr;
2432	Value *ResumeVal = Resume->getOperand(0);
2433	// If the resume value isn't a phi or landingpad value, it should be a
2434	// series of insertions. Identify them so we can avoid them when scanning
2435	// for cleanups.
2436	if (!isa<PHINode>(ResumeVal) && !isa<LandingPadInst>(ResumeVal)) {
2437	Insert2 = dyn_cast<InsertValueInst>(ResumeVal);
2438	if (!Insert2)
2439	return createCleanupHandler(Actions, CleanupHandlerMap, BB);
2440	Insert1 = dyn_cast<InsertValueInst>(Insert2->getAggregateOperand());
2441	if (!Insert1)
2442	return createCleanupHandler(Actions, CleanupHandlerMap, BB);
2443	}
2444	for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
2445	II != IE; ++II) {
2446	Instruction *Inst = II;
2447	if (LPadMap && LPadMap->isLandingPadSpecificInst(Inst))
2448	continue;
2449	if (Inst == Insert1 \|\| Inst == Insert2 \|\| Inst == Resume)
2450	continue;
2451	if (!Inst->hasOneUse() \|\|
2452	(Inst->user_back() != Insert1 && Inst->user_back() != Insert2)) {
2453	return createCleanupHandler(Actions, CleanupHandlerMap, BB);
2454	}
2455	}
2456	return;
2457	}
2458
2459	BranchInst *Branch = dyn_cast<BranchInst>(Terminator);
2460	if (Branch && Branch->isConditional()) {
2461	// Look for the selector dispatch.
2462	// %2 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIf to i8*))
2463	// %matches = icmp eq i32 %sel, %2
2464	// br i1 %matches, label %catch14, label %eh.resume
2465	CmpInst *Compare = dyn_cast<CmpInst>(Branch->getCondition());
2466	if (!Compare \|\| !Compare->isEquality())
2467	return createCleanupHandler(Actions, CleanupHandlerMap, BB);
2468	for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
2469	II != IE; ++II) {
2470	Instruction *Inst = II;
2471	if (LPadMap && LPadMap->isLandingPadSpecificInst(Inst))
2472	continue;
2473	if (Inst == Compare \|\| Inst == Branch)
2474	continue;
2475	if (match(Inst, m_Intrinsic<Intrinsic::eh_typeid_for>()))
2476	continue;
2477	return createCleanupHandler(Actions, CleanupHandlerMap, BB);
2478	}
2479	// The selector dispatch block should always terminate our search.
2480	assert(BB == EndBB)((BB == EndBB) ? static_cast<void> (0) : __assert_fail ( "BB == EndBB", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2480, __PRETTY_FUNCTION__));
2481	return;
2482	}
2483
2484	if (isAsynchronousEHPersonality(Personality)) {
2485	// If this is a landingpad block, split the block at the first non-landing
2486	// pad instruction.
2487	Instruction *MaybeCall = BB->getFirstNonPHIOrDbg();
2488	if (LPadMap) {
2489	while (MaybeCall != BB->getTerminator() &&
2490	LPadMap->isLandingPadSpecificInst(MaybeCall))
2491	MaybeCall = MaybeCall->getNextNode();
2492	}
2493
2494	// Look for outlined finally calls on x64, since those happen to match the
2495	// prototype provided by the runtime.
2496	if (TheTriple.getArch() == Triple::x86_64) {
2497	if (CallSite FinallyCall = matchOutlinedFinallyCall(BB, MaybeCall)) {
2498	Function *Fin = FinallyCall.getCalledFunction();
2499	assert(Fin && "outlined finally call should be direct")((Fin && "outlined finally call should be direct") ? static_cast <void> (0) : __assert_fail ("Fin && \"outlined finally call should be direct\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2499, __PRETTY_FUNCTION__));
2500	auto *Action = new CleanupHandler(BB);
2501	Action->setHandlerBlockOrFunc(Fin);
2502	Actions.insertCleanupHandler(Action);
2503	CleanupHandlerMap[BB] = Action;
2504	DEBUG(dbgs() << " Found frontend-outlined finally call to "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found frontend-outlined finally call to " << Fin->getName() << " in block " << Action ->getStartBlock()->getName() << "\n"; } } while ( 0)
2505	<< Fin->getName() << " in block "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found frontend-outlined finally call to " << Fin->getName() << " in block " << Action ->getStartBlock()->getName() << "\n"; } } while ( 0)
2506	<< Action->getStartBlock()->getName() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << " Found frontend-outlined finally call to " << Fin->getName() << " in block " << Action ->getStartBlock()->getName() << "\n"; } } while ( 0);
2507
2508	// Split the block if there were more interesting instructions and
2509	// look for finally calls in the normal successor block.
2510	BasicBlock *SuccBB = BB;
	Value stored to 'SuccBB' during its initialization is never read
2511	if (FinallyCall.getInstruction() != BB->getTerminator() &&
2512	FinallyCall.getInstruction()->getNextNode() !=
2513	BB->getTerminator()) {
2514	SuccBB =
2515	SplitBlock(BB, FinallyCall.getInstruction()->getNextNode(), DT);
2516	} else {
2517	if (FinallyCall.isInvoke()) {
2518	SuccBB = cast<InvokeInst>(FinallyCall.getInstruction())
2519	->getNormalDest();
2520	} else {
2521	SuccBB = BB->getUniqueSuccessor();
2522	assert(SuccBB &&((SuccBB && "splitOutlinedFinallyCalls didn't insert a branch" ) ? static_cast<void> (0) : __assert_fail ("SuccBB && \"splitOutlinedFinallyCalls didn't insert a branch\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2523, __PRETTY_FUNCTION__))
2523	"splitOutlinedFinallyCalls didn't insert a branch")((SuccBB && "splitOutlinedFinallyCalls didn't insert a branch" ) ? static_cast<void> (0) : __assert_fail ("SuccBB && \"splitOutlinedFinallyCalls didn't insert a branch\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2523, __PRETTY_FUNCTION__));
2524	}
2525	}
2526	BB = SuccBB;
2527	if (BB == EndBB)
2528	return;
2529	continue;
2530	}
2531	}
2532	}
2533
2534	// Anything else is either a catch block or interesting cleanup code.
2535	for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
2536	II != IE; ++II) {
2537	Instruction *Inst = II;
2538	if (LPadMap && LPadMap->isLandingPadSpecificInst(Inst))
2539	continue;
2540	// Unconditional branches fall through to this loop.
2541	if (Inst == Branch)
2542	continue;
2543	// If this is a catch block, there is no cleanup code to be found.
2544	if (match(Inst, m_Intrinsic<Intrinsic::eh_begincatch>()))
2545	return;
2546	// If this a nested landing pad, it may contain an endcatch call.
2547	if (match(Inst, m_Intrinsic<Intrinsic::eh_endcatch>()))
2548	return;
2549	// Anything else makes this interesting cleanup code.
2550	return createCleanupHandler(Actions, CleanupHandlerMap, BB);
2551	}
2552
2553	// Only unconditional branches in empty blocks should get this far.
2554	assert(Branch && Branch->isUnconditional())((Branch && Branch->isUnconditional()) ? static_cast <void> (0) : __assert_fail ("Branch && Branch->isUnconditional()" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2554, __PRETTY_FUNCTION__));
2555	if (BB == EndBB)
2556	return;
2557	BB = Branch->getSuccessor(0);
2558	}
2559	}
2560
2561	// This is a public function, declared in WinEHFuncInfo.h and is also
2562	// referenced by WinEHNumbering in FunctionLoweringInfo.cpp.
2563	void llvm::parseEHActions(
2564	const IntrinsicInst *II,
2565	SmallVectorImpl<std::unique_ptr<ActionHandler>> &Actions) {
2566	assert(II->getIntrinsicID() == Intrinsic::eh_actions &&((II->getIntrinsicID() == Intrinsic::eh_actions && "attempted to parse non eh.actions intrinsic") ? static_cast <void> (0) : __assert_fail ("II->getIntrinsicID() == Intrinsic::eh_actions && \"attempted to parse non eh.actions intrinsic\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2567, __PRETTY_FUNCTION__))
2567	"attempted to parse non eh.actions intrinsic")((II->getIntrinsicID() == Intrinsic::eh_actions && "attempted to parse non eh.actions intrinsic") ? static_cast <void> (0) : __assert_fail ("II->getIntrinsicID() == Intrinsic::eh_actions && \"attempted to parse non eh.actions intrinsic\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2567, __PRETTY_FUNCTION__));
2568	for (unsigned I = 0, E = II->getNumArgOperands(); I != E;) {
2569	uint64_t ActionKind =
2570	cast<ConstantInt>(II->getArgOperand(I))->getZExtValue();
2571	if (ActionKind == /catch=/1) {
2572	auto *Selector = cast<Constant>(II->getArgOperand(I + 1));
2573	ConstantInt *EHObjIndex = cast<ConstantInt>(II->getArgOperand(I + 2));
2574	int64_t EHObjIndexVal = EHObjIndex->getSExtValue();
2575	Constant *Handler = cast<Constant>(II->getArgOperand(I + 3));
2576	I += 4;
2577	auto CH = make_unique<CatchHandler>(/BB=/nullptr, Selector,
2578	/NextBB=/nullptr);
2579	CH->setHandlerBlockOrFunc(Handler);
2580	CH->setExceptionVarIndex(EHObjIndexVal);
2581	Actions.push_back(std::move(CH));
2582	} else if (ActionKind == 0) {
2583	Constant *Handler = cast<Constant>(II->getArgOperand(I + 1));
2584	I += 2;
2585	auto CH = make_unique<CleanupHandler>(/BB=/nullptr);
2586	CH->setHandlerBlockOrFunc(Handler);
2587	Actions.push_back(std::move(CH));
2588	} else {
2589	llvm_unreachable("Expected either a catch or cleanup handler!")::llvm::llvm_unreachable_internal("Expected either a catch or cleanup handler!" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2589);
2590	}
2591	}
2592	std::reverse(Actions.begin(), Actions.end());
2593	}
2594
2595	static int addUnwindMapEntry(WinEHFuncInfo &FuncInfo, int ToState,
2596	const Value *V) {
2597	WinEHUnwindMapEntry UME;
2598	UME.ToState = ToState;
2599	UME.Cleanup = V;
2600	FuncInfo.UnwindMap.push_back(UME);
2601	return FuncInfo.getLastStateNumber();
2602	}
2603
2604	static void addTryBlockMapEntry(WinEHFuncInfo &FuncInfo, int TryLow,
2605	int TryHigh, int CatchHigh,
2606	ArrayRef<const CatchPadInst *> Handlers) {
2607	WinEHTryBlockMapEntry TBME;
2608	TBME.TryLow = TryLow;
2609	TBME.TryHigh = TryHigh;
2610	TBME.CatchHigh = CatchHigh;
2611	assert(TBME.TryLow <= TBME.TryHigh)((TBME.TryLow <= TBME.TryHigh) ? static_cast<void> ( 0) : __assert_fail ("TBME.TryLow <= TBME.TryHigh", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2611, __PRETTY_FUNCTION__));
2612	for (const CatchPadInst *CPI : Handlers) {
2613	WinEHHandlerType HT;
2614	Constant *TypeInfo = cast<Constant>(CPI->getArgOperand(0));
2615	if (TypeInfo->isNullValue())
2616	HT.TypeDescriptor = nullptr;
2617	else
2618	HT.TypeDescriptor = cast<GlobalVariable>(TypeInfo->stripPointerCasts());
2619	HT.Adjectives = cast<ConstantInt>(CPI->getArgOperand(1))->getZExtValue();
2620	HT.Handler = CPI->getParent();
2621	HT.CatchObjRecoverIdx = -2;
2622	if (isa<ConstantPointerNull>(CPI->getArgOperand(2)))
2623	HT.CatchObj.Alloca = nullptr;
2624	else
2625	HT.CatchObj.Alloca = cast<AllocaInst>(CPI->getArgOperand(2));
2626	TBME.HandlerArray.push_back(HT);
2627	}
2628	FuncInfo.TryBlockMap.push_back(TBME);
2629	}
2630
2631	static const CatchPadInst getSingleCatchPadPredecessor(const BasicBlock BB) {
2632	for (const BasicBlock *PredBlock : predecessors(BB))
2633	if (auto *CPI = dyn_cast<CatchPadInst>(PredBlock->getFirstNonPHI()))
2634	return CPI;
2635	return nullptr;
2636	}
2637
2638	/// Find all the catchpads that feed directly into the catchendpad. Frontends
2639	/// using this personality should ensure that each catchendpad and catchpad has
2640	/// one or zero catchpad predecessors.
2641	///
2642	/// The following C++ generates the IR after it:
2643	/// try {
2644	/// } catch (A) {
2645	/// } catch (B) {
2646	/// }
2647	///
2648	/// IR:
2649	/// %catchpad.A
2650	/// catchpad [i8* A typeinfo]
2651	/// to label %catch.A unwind label %catchpad.B
2652	/// %catchpad.B
2653	/// catchpad [i8* B typeinfo]
2654	/// to label %catch.B unwind label %endcatches
2655	/// %endcatches
2656	/// catchendblock unwind to caller
2657	static void
2658	findCatchPadsForCatchEndPad(const BasicBlock *CatchEndBB,
2659	SmallVectorImpl<const CatchPadInst *> &Handlers) {
2660	const CatchPadInst *CPI = getSingleCatchPadPredecessor(CatchEndBB);
2661	while (CPI) {
2662	Handlers.push_back(CPI);
2663	CPI = getSingleCatchPadPredecessor(CPI->getParent());
2664	}
2665	// We've pushed these back into reverse source order. Reverse them to get
2666	// the list back into source order.
2667	std::reverse(Handlers.begin(), Handlers.end());
2668	}
2669
2670	// Given BB which ends in an unwind edge, return the EHPad that this BB belongs
2671	// to. If the unwind edge came from an invoke, return null.
2672	static const BasicBlock getEHPadFromPredecessor(const BasicBlock BB) {
2673	const TerminatorInst *TI = BB->getTerminator();
2674	if (isa<InvokeInst>(TI))
2675	return nullptr;
2676	if (TI->isEHPad())
2677	return BB;
2678	return cast<CleanupReturnInst>(TI)->getCleanupPad()->getParent();
2679	}
2680
2681	static void calculateExplicitCXXStateNumbers(WinEHFuncInfo &FuncInfo,
2682	const BasicBlock &BB,
2683	int ParentState) {
2684	assert(BB.isEHPad())((BB.isEHPad()) ? static_cast<void> (0) : __assert_fail ("BB.isEHPad()", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2684, __PRETTY_FUNCTION__));
2685	const Instruction *FirstNonPHI = BB.getFirstNonPHI();
2686	// All catchpad instructions will be handled when we process their
2687	// respective catchendpad instruction.
2688	if (isa<CatchPadInst>(FirstNonPHI))
2689	return;
2690
2691	if (isa<CatchEndPadInst>(FirstNonPHI)) {
2692	SmallVector<const CatchPadInst *, 2> Handlers;
2693	findCatchPadsForCatchEndPad(&BB, Handlers);
2694	const BasicBlock *FirstTryPad = Handlers.front()->getParent();
2695	int TryLow = addUnwindMapEntry(FuncInfo, ParentState, nullptr);
2696	FuncInfo.EHPadStateMap[Handlers.front()] = TryLow;
2697	for (const BasicBlock *PredBlock : predecessors(FirstTryPad))
2698	if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
2699	calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, TryLow);
2700	int CatchLow = addUnwindMapEntry(FuncInfo, ParentState, nullptr);
2701
2702	// catchpads are separate funclets in C++ EH due to the way rethrow works.
2703	// In SEH, they aren't, so no invokes will unwind to the catchendpad.
2704	FuncInfo.EHPadStateMap[FirstNonPHI] = CatchLow;
2705	int TryHigh = CatchLow - 1;
2706	for (const BasicBlock *PredBlock : predecessors(&BB))
2707	if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
2708	calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, CatchLow);
2709	int CatchHigh = FuncInfo.getLastStateNumber();
2710	addTryBlockMapEntry(FuncInfo, TryLow, TryHigh, CatchHigh, Handlers);
2711	DEBUG(dbgs() << "TryLow[" << FirstTryPad->getName() << "]: " << TryLowdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "TryLow[" << FirstTryPad ->getName() << "]: " << TryLow << '\n'; } } while (0)
2712	<< '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "TryLow[" << FirstTryPad ->getName() << "]: " << TryLow << '\n'; } } while (0);
2713	DEBUG(dbgs() << "TryHigh[" << FirstTryPad->getName() << "]: " << TryHighdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "TryHigh[" << FirstTryPad ->getName() << "]: " << TryHigh << '\n'; } } while (0)
2714	<< '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "TryHigh[" << FirstTryPad ->getName() << "]: " << TryHigh << '\n'; } } while (0);
2715	DEBUG(dbgs() << "CatchHigh[" << FirstTryPad->getName() << "]: " << CatchHighdo { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "CatchHigh[" << FirstTryPad ->getName() << "]: " << CatchHigh << '\n' ; } } while (0)
2716	<< '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "CatchHigh[" << FirstTryPad ->getName() << "]: " << CatchHigh << '\n' ; } } while (0);
2717	} else if (isa<CleanupPadInst>(FirstNonPHI)) {
2718	// A cleanup can have multiple exits; don't re-process after the first.
2719	if (FuncInfo.EHPadStateMap.count(FirstNonPHI))
2720	return;
2721	int CleanupState = addUnwindMapEntry(FuncInfo, ParentState, &BB);
2722	FuncInfo.EHPadStateMap[FirstNonPHI] = CleanupState;
2723	DEBUG(dbgs() << "Assigning state #" << CleanupState << " to BB "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Assigning state #" << CleanupState << " to BB " << BB.getName() << '\n'; } } while (0)
2724	<< BB.getName() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Assigning state #" << CleanupState << " to BB " << BB.getName() << '\n'; } } while (0);
2725	for (const BasicBlock *PredBlock : predecessors(&BB))
2726	if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
2727	calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, CleanupState);
2728	} else if (auto *CEPI = dyn_cast<CleanupEndPadInst>(FirstNonPHI)) {
2729	// Propagate ParentState to the cleanuppad in case it doesn't have
2730	// any cleanuprets.
2731	BasicBlock *CleanupBlock = CEPI->getCleanupPad()->getParent();
2732	calculateExplicitCXXStateNumbers(FuncInfo, *CleanupBlock, ParentState);
2733	// Anything unwinding through CleanupEndPadInst is in ParentState.
2734	for (const BasicBlock *PredBlock : predecessors(&BB))
2735	if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
2736	calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, ParentState);
2737	} else if (isa<TerminatePadInst>(FirstNonPHI)) {
2738	report_fatal_error("Not yet implemented!");
2739	} else {
2740	llvm_unreachable("unexpected EH Pad!")::llvm::llvm_unreachable_internal("unexpected EH Pad!", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2740);
2741	}
2742	}
2743
2744	static int addSEHExcept(WinEHFuncInfo &FuncInfo, int ParentState,
2745	const Function Filter, const BasicBlock Handler) {
2746	SEHUnwindMapEntry Entry;
2747	Entry.ToState = ParentState;
2748	Entry.IsFinally = false;
2749	Entry.Filter = Filter;
2750	Entry.Handler = Handler;
2751	FuncInfo.SEHUnwindMap.push_back(Entry);
2752	return FuncInfo.SEHUnwindMap.size() - 1;
2753	}
2754
2755	static int addSEHFinally(WinEHFuncInfo &FuncInfo, int ParentState,
2756	const BasicBlock *Handler) {
2757	SEHUnwindMapEntry Entry;
2758	Entry.ToState = ParentState;
2759	Entry.IsFinally = true;
2760	Entry.Filter = nullptr;
2761	Entry.Handler = Handler;
2762	FuncInfo.SEHUnwindMap.push_back(Entry);
2763	return FuncInfo.SEHUnwindMap.size() - 1;
2764	}
2765
2766	static void calculateExplicitSEHStateNumbers(WinEHFuncInfo &FuncInfo,
2767	const BasicBlock &BB,
2768	int ParentState) {
2769	assert(BB.isEHPad())((BB.isEHPad()) ? static_cast<void> (0) : __assert_fail ("BB.isEHPad()", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2769, __PRETTY_FUNCTION__));
2770	const Instruction *FirstNonPHI = BB.getFirstNonPHI();
2771	// All catchpad instructions will be handled when we process their
2772	// respective catchendpad instruction.
2773	if (isa<CatchPadInst>(FirstNonPHI))
2774	return;
2775
2776	if (isa<CatchEndPadInst>(FirstNonPHI)) {
2777	// Extract the filter function and the __except basic block and create a
2778	// state for them.
2779	SmallVector<const CatchPadInst *, 1> Handlers;
2780	findCatchPadsForCatchEndPad(&BB, Handlers);
2781	assert(Handlers.size() == 1 &&((Handlers.size() == 1 && "SEH doesn't have multiple handlers per __try" ) ? static_cast<void> (0) : __assert_fail ("Handlers.size() == 1 && \"SEH doesn't have multiple handlers per __try\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2782, __PRETTY_FUNCTION__))
2782	"SEH doesn't have multiple handlers per __try")((Handlers.size() == 1 && "SEH doesn't have multiple handlers per __try" ) ? static_cast<void> (0) : __assert_fail ("Handlers.size() == 1 && \"SEH doesn't have multiple handlers per __try\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2782, __PRETTY_FUNCTION__));
2783	const CatchPadInst *CPI = Handlers.front();
2784	const BasicBlock *CatchPadBB = CPI->getParent();
2785	const Constant *FilterOrNull =
2786	cast<Constant>(CPI->getArgOperand(0)->stripPointerCasts());
2787	const Function *Filter = dyn_cast<Function>(FilterOrNull);
2788	assert((Filter \|\| FilterOrNull->isNullValue()) &&(((Filter \|\| FilterOrNull->isNullValue()) && "unexpected filter value" ) ? static_cast<void> (0) : __assert_fail ("(Filter \|\| FilterOrNull->isNullValue()) && \"unexpected filter value\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2789, __PRETTY_FUNCTION__))
2789	"unexpected filter value")(((Filter \|\| FilterOrNull->isNullValue()) && "unexpected filter value" ) ? static_cast<void> (0) : __assert_fail ("(Filter \|\| FilterOrNull->isNullValue()) && \"unexpected filter value\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2789, __PRETTY_FUNCTION__));
2790	int TryState = addSEHExcept(FuncInfo, ParentState, Filter, CatchPadBB);
2791
2792	// Everything in the __try block uses TryState as its parent state.
2793	FuncInfo.EHPadStateMap[CPI] = TryState;
2794	DEBUG(dbgs() << "Assigning state #" << TryState << " to BB "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Assigning state #" << TryState << " to BB " << CatchPadBB->getName( ) << '\n'; } } while (0)
2795	<< CatchPadBB->getName() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Assigning state #" << TryState << " to BB " << CatchPadBB->getName( ) << '\n'; } } while (0);
2796	for (const BasicBlock *PredBlock : predecessors(CatchPadBB))
2797	if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
2798	calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, TryState);
2799
2800	// Everything in the __except block unwinds to ParentState, just like code
2801	// outside the __try.
2802	FuncInfo.EHPadStateMap[FirstNonPHI] = ParentState;
2803	DEBUG(dbgs() << "Assigning state #" << ParentState << " to BB "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Assigning state #" << ParentState << " to BB " << BB.getName() << '\n'; } } while (0)
2804	<< BB.getName() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Assigning state #" << ParentState << " to BB " << BB.getName() << '\n'; } } while (0);
2805	for (const BasicBlock *PredBlock : predecessors(&BB))
2806	if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
2807	calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, ParentState);
2808	} else if (isa<CleanupPadInst>(FirstNonPHI)) {
2809	// A cleanup can have multiple exits; don't re-process after the first.
2810	if (FuncInfo.EHPadStateMap.count(FirstNonPHI))
2811	return;
2812	int CleanupState = addSEHFinally(FuncInfo, ParentState, &BB);
2813	FuncInfo.EHPadStateMap[FirstNonPHI] = CleanupState;
2814	DEBUG(dbgs() << "Assigning state #" << CleanupState << " to BB "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Assigning state #" << CleanupState << " to BB " << BB.getName() << '\n'; } } while (0)
2815	<< BB.getName() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Assigning state #" << CleanupState << " to BB " << BB.getName() << '\n'; } } while (0);
2816	for (const BasicBlock *PredBlock : predecessors(&BB))
2817	if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
2818	calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, CleanupState);
2819	} else if (auto *CEPI = dyn_cast<CleanupEndPadInst>(FirstNonPHI)) {
2820	// Propagate ParentState to the cleanuppad in case it doesn't have
2821	// any cleanuprets.
2822	BasicBlock *CleanupBlock = CEPI->getCleanupPad()->getParent();
2823	calculateExplicitSEHStateNumbers(FuncInfo, *CleanupBlock, ParentState);
2824	// Anything unwinding through CleanupEndPadInst is in ParentState.
2825	FuncInfo.EHPadStateMap[FirstNonPHI] = ParentState;
2826	DEBUG(dbgs() << "Assigning state #" << ParentState << " to BB "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Assigning state #" << ParentState << " to BB " << BB.getName() << '\n'; } } while (0)
2827	<< BB.getName() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("winehprepare")) { dbgs() << "Assigning state #" << ParentState << " to BB " << BB.getName() << '\n'; } } while (0);
2828	for (const BasicBlock *PredBlock : predecessors(&BB))
2829	if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
2830	calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, ParentState);
2831	} else if (isa<TerminatePadInst>(FirstNonPHI)) {
2832	report_fatal_error("Not yet implemented!");
2833	} else {
2834	llvm_unreachable("unexpected EH Pad!")::llvm::llvm_unreachable_internal("unexpected EH Pad!", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2834);
2835	}
2836	}
2837
2838	/// Check if the EH Pad unwinds to caller. Cleanups are a little bit of a
2839	/// special case because we have to look at the cleanupret instruction that uses
2840	/// the cleanuppad.
2841	static bool doesEHPadUnwindToCaller(const Instruction *EHPad) {
2842	auto *CPI = dyn_cast<CleanupPadInst>(EHPad);
2843	if (!CPI)
2844	return EHPad->mayThrow();
2845
2846	// This cleanup does not return or unwind, so we say it unwinds to caller.
2847	if (CPI->use_empty())
2848	return true;
2849
2850	const Instruction *User = CPI->user_back();
2851	if (auto *CRI = dyn_cast<CleanupReturnInst>(User))
2852	return CRI->unwindsToCaller();
2853	return cast<CleanupEndPadInst>(User)->unwindsToCaller();
2854	}
2855
2856	void llvm::calculateSEHStateNumbers(const Function *Fn,
2857	WinEHFuncInfo &FuncInfo) {
2858	// Don't compute state numbers twice.
2859	if (!FuncInfo.SEHUnwindMap.empty())
2860	return;
2861
2862	for (const BasicBlock &BB : *Fn) {
2863	if (!BB.isEHPad() \|\| !doesEHPadUnwindToCaller(BB.getFirstNonPHI()))
2864	continue;
2865	calculateExplicitSEHStateNumbers(FuncInfo, BB, -1);
2866	}
2867	}
2868
2869	void llvm::calculateWinCXXEHStateNumbers(const Function *Fn,
2870	WinEHFuncInfo &FuncInfo) {
2871	// Return if it's already been done.
2872	if (!FuncInfo.EHPadStateMap.empty())
2873	return;
2874
2875	for (const BasicBlock &BB : *Fn) {
2876	if (!BB.isEHPad())
2877	continue;
2878	if (BB.isLandingPad())
2879	report_fatal_error("MSVC C++ EH cannot use landingpads");
2880	const Instruction *FirstNonPHI = BB.getFirstNonPHI();
2881	if (!doesEHPadUnwindToCaller(FirstNonPHI))
2882	continue;
2883	calculateExplicitCXXStateNumbers(FuncInfo, BB, -1);
2884	}
2885	}
2886
2887	static int addClrEHHandler(WinEHFuncInfo &FuncInfo, int ParentState,
2888	ClrHandlerType HandlerType, uint32_t TypeToken,
2889	const BasicBlock *Handler) {
2890	ClrEHUnwindMapEntry Entry;
2891	Entry.Parent = ParentState;
2892	Entry.Handler = Handler;
2893	Entry.HandlerType = HandlerType;
2894	Entry.TypeToken = TypeToken;
2895	FuncInfo.ClrEHUnwindMap.push_back(Entry);
2896	return FuncInfo.ClrEHUnwindMap.size() - 1;
2897	}
2898
2899	void llvm::calculateClrEHStateNumbers(const Function *Fn,
2900	WinEHFuncInfo &FuncInfo) {
2901	// Return if it's already been done.
2902	if (!FuncInfo.EHPadStateMap.empty())
2903	return;
2904
2905	SmallVector<std::pair<const Instruction *, int>, 8> Worklist;
2906
2907	// Each pad needs to be able to refer to its parent, so scan the function
2908	// looking for top-level handlers and seed the worklist with them.
2909	for (const BasicBlock &BB : *Fn) {
2910	if (!BB.isEHPad())
2911	continue;
2912	if (BB.isLandingPad())
2913	report_fatal_error("CoreCLR EH cannot use landingpads");
2914	const Instruction *FirstNonPHI = BB.getFirstNonPHI();
2915	if (!doesEHPadUnwindToCaller(FirstNonPHI))
2916	continue;
2917	// queue this with sentinel parent state -1 to mean unwind to caller.
2918	Worklist.emplace_back(FirstNonPHI, -1);
2919	}
2920
2921	while (!Worklist.empty()) {
2922	const Instruction *Pad;
2923	int ParentState;
2924	std::tie(Pad, ParentState) = Worklist.pop_back_val();
2925
2926	int PredState;
2927	if (const CleanupEndPadInst *EndPad = dyn_cast<CleanupEndPadInst>(Pad)) {
2928	FuncInfo.EHPadStateMap[EndPad] = ParentState;
2929	// Queue the cleanuppad, in case it doesn't have a cleanupret.
2930	Worklist.emplace_back(EndPad->getCleanupPad(), ParentState);
2931	// Preds of the endpad should get the parent state.
2932	PredState = ParentState;
2933	} else if (const CleanupPadInst *Cleanup = dyn_cast<CleanupPadInst>(Pad)) {
2934	// A cleanup can have multiple exits; don't re-process after the first.
2935	if (FuncInfo.EHPadStateMap.count(Pad))
2936	continue;
2937	// CoreCLR personality uses arity to distinguish faults from finallies.
2938	const BasicBlock *PadBlock = Cleanup->getParent();
2939	ClrHandlerType HandlerType =
2940	(Cleanup->getNumOperands() ? ClrHandlerType::Fault
2941	: ClrHandlerType::Finally);
2942	int NewState =
2943	addClrEHHandler(FuncInfo, ParentState, HandlerType, 0, PadBlock);
2944	FuncInfo.EHPadStateMap[Cleanup] = NewState;
2945	// Propagate the new state to all preds of the cleanup
2946	PredState = NewState;
2947	} else if (const CatchEndPadInst *EndPad = dyn_cast<CatchEndPadInst>(Pad)) {
2948	FuncInfo.EHPadStateMap[EndPad] = ParentState;
2949	// Preds of the endpad should get the parent state.
2950	PredState = ParentState;
2951	} else if (const CatchPadInst *Catch = dyn_cast<CatchPadInst>(Pad)) {
2952	const BasicBlock *PadBlock = Catch->getParent();
2953	uint32_t TypeToken = static_cast<uint32_t>(
2954	cast<ConstantInt>(Catch->getArgOperand(0))->getZExtValue());
2955	int NewState = addClrEHHandler(FuncInfo, ParentState,
2956	ClrHandlerType::Catch, TypeToken, PadBlock);
2957	FuncInfo.EHPadStateMap[Catch] = NewState;
2958	// Preds of the catch get its state
2959	PredState = NewState;
2960	} else {
2961	llvm_unreachable("Unexpected EH pad")::llvm::llvm_unreachable_internal("Unexpected EH pad", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 2961);
2962	}
2963
2964	// Queue all predecessors with the given state
2965	for (const BasicBlock *Pred : predecessors(Pad->getParent())) {
2966	if ((Pred = getEHPadFromPredecessor(Pred)))
2967	Worklist.emplace_back(Pred->getFirstNonPHI(), PredState);
2968	}
2969	}
2970	}
2971
2972	void WinEHPrepare::replaceTerminatePadWithCleanup(Function &F) {
2973	if (Personality != EHPersonality::MSVC_CXX)
2974	return;
2975	for (BasicBlock &BB : F) {
2976	Instruction *First = BB.getFirstNonPHI();
2977	auto *TPI = dyn_cast<TerminatePadInst>(First);
2978	if (!TPI)
2979	continue;
2980
2981	if (TPI->getNumArgOperands() != 1)
2982	report_fatal_error(
2983	"Expected a unary terminatepad for MSVC C++ personalities!");
2984
2985	auto *TerminateFn = dyn_cast<Function>(TPI->getArgOperand(0));
2986	if (!TerminateFn)
2987	report_fatal_error("Function operand expected in terminatepad for MSVC "
2988	"C++ personalities!");
2989
2990	// Insert the cleanuppad instruction.
2991	auto *CPI = CleanupPadInst::Create(
2992	BB.getContext(), {}, Twine("terminatepad.for.", BB.getName()), &BB);
2993
2994	// Insert the call to the terminate instruction.
2995	auto *CallTerminate = CallInst::Create(TerminateFn, {}, &BB);
2996	CallTerminate->setDoesNotThrow();
2997	CallTerminate->setDoesNotReturn();
2998	CallTerminate->setCallingConv(TerminateFn->getCallingConv());
2999
3000	// Insert a new terminator for the cleanuppad using the same successor as
3001	// the terminatepad.
3002	CleanupReturnInst::Create(CPI, TPI->getUnwindDest(), &BB);
3003
3004	// Let's remove the terminatepad now that we've inserted the new
3005	// instructions.
3006	TPI->eraseFromParent();
3007	}
3008	}
3009
3010	static void
3011	colorFunclets(Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks,
3012	std::map<BasicBlock , std::set<BasicBlock >> &BlockColors,
3013	std::map<BasicBlock , std::set<BasicBlock >> &FuncletBlocks,
3014	std::map<BasicBlock , std::set<BasicBlock >> &FuncletChildren) {
3015	SmallVector<std::pair<BasicBlock , BasicBlock >, 16> Worklist;
3016	BasicBlock *EntryBlock = &F.getEntryBlock();
3017
3018	// Build up the color map, which maps each block to its set of 'colors'.
3019	// For any block B, the "colors" of B are the set of funclets F (possibly
3020	// including a root "funclet" representing the main function), such that
3021	// F will need to directly contain B or a copy of B (where the term "directly
3022	// contain" is used to distinguish from being "transitively contained" in
3023	// a nested funclet).
3024	// Use a CFG walk driven by a worklist of (block, color) pairs. The "color"
3025	// sets attached during this processing to a block which is the entry of some
3026	// funclet F is actually the set of F's parents -- i.e. the union of colors
3027	// of all predecessors of F's entry. For all other blocks, the color sets
3028	// are as defined above. A post-pass fixes up the block color map to reflect
3029	// the same sense of "color" for funclet entries as for other blocks.
3030
3031	Worklist.push_back({EntryBlock, EntryBlock});
3032
3033	while (!Worklist.empty()) {
3034	BasicBlock *Visiting;
3035	BasicBlock *Color;
3036	std::tie(Visiting, Color) = Worklist.pop_back_val();
3037	Instruction *VisitingHead = Visiting->getFirstNonPHI();
3038	if (VisitingHead->isEHPad() && !isa<CatchEndPadInst>(VisitingHead) &&
3039	!isa<CleanupEndPadInst>(VisitingHead)) {
3040	// Mark this as a funclet head as a member of itself.
3041	FuncletBlocks[Visiting].insert(Visiting);
3042	// Queue exits with the parent color.
3043	for (User *U : VisitingHead->users()) {
3044	if (auto *Exit = dyn_cast<TerminatorInst>(U)) {
3045	for (BasicBlock *Succ : successors(Exit->getParent()))
3046	if (BlockColors[Succ].insert(Color).second)
3047	Worklist.push_back({Succ, Color});
3048	}
3049	}
3050	// Handle CatchPad specially since its successors need different colors.
3051	if (CatchPadInst *CatchPad = dyn_cast<CatchPadInst>(VisitingHead)) {
3052	// Visit the normal successor with the color of the new EH pad, and
3053	// visit the unwind successor with the color of the parent.
3054	BasicBlock *NormalSucc = CatchPad->getNormalDest();
3055	if (BlockColors[NormalSucc].insert(Visiting).second) {
3056	Worklist.push_back({NormalSucc, Visiting});
3057	}
3058	BasicBlock *UnwindSucc = CatchPad->getUnwindDest();
3059	if (BlockColors[UnwindSucc].insert(Color).second) {
3060	Worklist.push_back({UnwindSucc, Color});
3061	}
3062	continue;
3063	}
3064	// Switch color to the current node, except for terminate pads which
3065	// have no bodies and only unwind successors and so need their successors
3066	// visited with the color of the parent.
3067	if (!isa<TerminatePadInst>(VisitingHead))
3068	Color = Visiting;
3069	} else {
3070	// Note that this is a member of the given color.
3071	FuncletBlocks[Color].insert(Visiting);
3072	}
3073
3074	TerminatorInst *Terminator = Visiting->getTerminator();
3075	if (isa<CleanupReturnInst>(Terminator) \|\|
3076	isa<CatchReturnInst>(Terminator) \|\|
3077	isa<CleanupEndPadInst>(Terminator)) {
3078	// These blocks' successors have already been queued with the parent
3079	// color.
3080	continue;
3081	}
3082	for (BasicBlock *Succ : successors(Visiting)) {
3083	if (isa<CatchEndPadInst>(Succ->getFirstNonPHI())) {
3084	// The catchendpad needs to be visited with the parent's color, not
3085	// the current color. This will happen in the code above that visits
3086	// any catchpad unwind successor with the parent color, so we can
3087	// safely skip this successor here.
3088	continue;
3089	}
3090	if (BlockColors[Succ].insert(Color).second) {
3091	Worklist.push_back({Succ, Color});
3092	}
3093	}
3094	}
3095
3096	// The processing above actually accumulated the parent set for this
3097	// funclet into the color set for its entry; use the parent set to
3098	// populate the children map, and reset the color set to include just
3099	// the funclet itself (no instruction can target a funclet entry except on
3100	// that transitions to the child funclet).
3101	for (BasicBlock *FuncletEntry : EntryBlocks) {
3102	std::set<BasicBlock *> &ColorMapItem = BlockColors[FuncletEntry];
3103	for (BasicBlock *Parent : ColorMapItem)
3104	FuncletChildren[Parent].insert(FuncletEntry);
3105	ColorMapItem.clear();
3106	ColorMapItem.insert(FuncletEntry);
3107	}
3108	}
3109
3110	void WinEHPrepare::colorFunclets(Function &F,
3111	SmallVectorImpl<BasicBlock *> &EntryBlocks) {
3112	::colorFunclets(F, EntryBlocks, BlockColors, FuncletBlocks, FuncletChildren);
3113	}
3114
3115	void llvm::calculateCatchReturnSuccessorColors(const Function *Fn,
3116	WinEHFuncInfo &FuncInfo) {
3117	SmallVector<LandingPadInst *, 4> LPads;
3118	SmallVector<ResumeInst *, 4> Resumes;
3119	SmallVector<BasicBlock *, 4> EntryBlocks;
3120	// colorFunclets needs the set of EntryBlocks, get them using
3121	// findExceptionalConstructs.
3122	bool ForExplicitEH = findExceptionalConstructs(const_cast<Function &>(*Fn),
3123	LPads, Resumes, EntryBlocks);
3124	if (!ForExplicitEH)
3125	return;
3126
3127	std::map<BasicBlock , std::set<BasicBlock >> BlockColors;
3128	std::map<BasicBlock , std::set<BasicBlock >> FuncletBlocks;
3129	std::map<BasicBlock , std::set<BasicBlock >> FuncletChildren;
3130	// Figure out which basic blocks belong to which funclets.
3131	colorFunclets(const_cast<Function &>(*Fn), EntryBlocks, BlockColors,
3132	FuncletBlocks, FuncletChildren);
3133
3134	// We need to find the catchret successors. To do this, we must first find
3135	// all the catchpad funclets.
3136	for (auto &Funclet : FuncletBlocks) {
3137	// Figure out what kind of funclet we are looking at; We only care about
3138	// catchpads.
3139	BasicBlock *FuncletPadBB = Funclet.first;
3140	Instruction *FirstNonPHI = FuncletPadBB->getFirstNonPHI();
3141	auto *CatchPad = dyn_cast<CatchPadInst>(FirstNonPHI);
3142	if (!CatchPad)
3143	continue;
3144
3145	// The users of a catchpad are always catchrets.
3146	for (User *Exit : CatchPad->users()) {
3147	auto *CatchReturn = dyn_cast<CatchReturnInst>(Exit);
3148	if (!CatchReturn)
3149	continue;
3150	BasicBlock *CatchRetSuccessor = CatchReturn->getSuccessor();
3151	std::set<BasicBlock *> &SuccessorColors = BlockColors[CatchRetSuccessor];
3152	assert(SuccessorColors.size() == 1 && "Expected BB to be monochrome!")((SuccessorColors.size() == 1 && "Expected BB to be monochrome!" ) ? static_cast<void> (0) : __assert_fail ("SuccessorColors.size() == 1 && \"Expected BB to be monochrome!\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 3152, __PRETTY_FUNCTION__));
3153	BasicBlock Color = SuccessorColors.begin();
3154	if (auto *CPI = dyn_cast<CatchPadInst>(Color->getFirstNonPHI()))
3155	Color = CPI->getNormalDest();
3156	// Record the catchret successor's funclet membership.
3157	FuncInfo.CatchRetSuccessorColorMap[CatchReturn] = Color;
3158	}
3159	}
3160	}
3161
3162	void WinEHPrepare::demotePHIsOnFunclets(Function &F) {
3163	// Strip PHI nodes off of EH pads.
3164	SmallVector<PHINode *, 16> PHINodes;
3165	for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE;) {
3166	BasicBlock *BB = FI++;
3167	if (!BB->isEHPad())
3168	continue;
3169	for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE;) {
3170	Instruction *I = BI++;
3171	auto *PN = dyn_cast<PHINode>(I);
3172	// Stop at the first non-PHI.
3173	if (!PN)
3174	break;
3175
3176	AllocaInst *SpillSlot = insertPHILoads(PN, F);
3177	if (SpillSlot)
3178	insertPHIStores(PN, SpillSlot);
3179
3180	PHINodes.push_back(PN);
3181	}
3182	}
3183
3184	for (auto *PN : PHINodes) {
3185	// There may be lingering uses on other EH PHIs being removed
3186	PN->replaceAllUsesWith(UndefValue::get(PN->getType()));
3187	PN->eraseFromParent();
3188	}
3189	}
3190
3191	void WinEHPrepare::demoteUsesBetweenFunclets(Function &F) {
3192	// Turn all inter-funclet uses of a Value into loads and stores.
3193	for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE;) {
3194	BasicBlock *BB = FI++;
3195	std::set<BasicBlock *> &ColorsForBB = BlockColors[BB];
3196	for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE;) {
3197	Instruction *I = BI++;
3198	// Funclets are permitted to use static allocas.
3199	if (auto *AI = dyn_cast<AllocaInst>(I))
3200	if (AI->isStaticAlloca())
3201	continue;
3202
3203	demoteNonlocalUses(I, ColorsForBB, F);
3204	}
3205	}
3206	}
3207
3208	void WinEHPrepare::demoteArgumentUses(Function &F) {
3209	// Also demote function parameters used in funclets.
3210	std::set<BasicBlock *> &ColorsForEntry = BlockColors[&F.getEntryBlock()];
3211	for (Argument &Arg : F.args())
3212	demoteNonlocalUses(&Arg, ColorsForEntry, F);
3213	}
3214
3215	void WinEHPrepare::cloneCommonBlocks(
3216	Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks) {
3217	// We need to clone all blocks which belong to multiple funclets. Values are
3218	// remapped throughout the funclet to propogate both the new instructions
3219	// and the new basic blocks themselves.
3220	for (BasicBlock *FuncletPadBB : EntryBlocks) {
3221	std::set<BasicBlock *> &BlocksInFunclet = FuncletBlocks[FuncletPadBB];
3222
3223	std::map<BasicBlock , BasicBlock > Orig2Clone;
3224	ValueToValueMapTy VMap;
3225	for (BasicBlock *BB : BlocksInFunclet) {
3226	std::set<BasicBlock *> &ColorsForBB = BlockColors[BB];
3227	// We don't need to do anything if the block is monochromatic.
3228	size_t NumColorsForBB = ColorsForBB.size();
3229	if (NumColorsForBB == 1)
3230	continue;
3231
3232	// Create a new basic block and copy instructions into it!
3233	BasicBlock *CBB =
3234	CloneBasicBlock(BB, VMap, Twine(".for.", FuncletPadBB->getName()));
3235	// Insert the clone immediately after the original to ensure determinism
3236	// and to keep the same relative ordering of any funclet's blocks.
3237	CBB->insertInto(&F, BB->getNextNode());
3238
3239	// Add basic block mapping.
3240	VMap[BB] = CBB;
3241
3242	// Record delta operations that we need to perform to our color mappings.
3243	Orig2Clone[BB] = CBB;
3244	}
3245
3246	// If nothing was cloned, we're done cloning in this funclet.
3247	if (Orig2Clone.empty())
3248	continue;
3249
3250	// Update our color mappings to reflect that one block has lost a color and
3251	// another has gained a color.
3252	for (auto &BBMapping : Orig2Clone) {
3253	BasicBlock *OldBlock = BBMapping.first;
3254	BasicBlock *NewBlock = BBMapping.second;
3255
3256	BlocksInFunclet.insert(NewBlock);
3257	BlockColors[NewBlock].insert(FuncletPadBB);
3258
3259	BlocksInFunclet.erase(OldBlock);
3260	BlockColors[OldBlock].erase(FuncletPadBB);
3261	}
3262
3263	// Loop over all of the instructions in this funclet, fixing up operand
3264	// references as we go. This uses VMap to do all the hard work.
3265	for (BasicBlock *BB : BlocksInFunclet)
3266	// Loop over all instructions, fixing each one as we find it...
3267	for (Instruction &I : *BB)
3268	RemapInstruction(&I, VMap,
3269	RF_IgnoreMissingEntries \| RF_NoModuleLevelChanges);
3270
3271	// Check to see if SuccBB has PHI nodes. If so, we need to add entries to
3272	// the PHI nodes for NewBB now.
3273	for (auto &BBMapping : Orig2Clone) {
3274	BasicBlock *OldBlock = BBMapping.first;
3275	BasicBlock *NewBlock = BBMapping.second;
3276	for (BasicBlock *SuccBB : successors(NewBlock)) {
3277	for (Instruction &SuccI : *SuccBB) {
3278	auto *SuccPN = dyn_cast<PHINode>(&SuccI);
3279	if (!SuccPN)
3280	break;
3281
3282	// Ok, we have a PHI node. Figure out what the incoming value was for
3283	// the OldBlock.
3284	int OldBlockIdx = SuccPN->getBasicBlockIndex(OldBlock);
3285	if (OldBlockIdx == -1)
3286	break;
3287	Value *IV = SuccPN->getIncomingValue(OldBlockIdx);
3288
3289	// Remap the value if necessary.
3290	if (auto *Inst = dyn_cast<Instruction>(IV)) {
3291	ValueToValueMapTy::iterator I = VMap.find(Inst);
3292	if (I != VMap.end())
3293	IV = I->second;
3294	}
3295
3296	SuccPN->addIncoming(IV, NewBlock);
3297	}
3298	}
3299	}
3300
3301	for (ValueToValueMapTy::value_type VT : VMap) {
3302	// If there were values defined in BB that are used outside the funclet,
3303	// then we now have to update all uses of the value to use either the
3304	// original value, the cloned value, or some PHI derived value. This can
3305	// require arbitrary PHI insertion, of which we are prepared to do, clean
3306	// these up now.
3307	SmallVector<Use *, 16> UsesToRename;
3308
3309	auto OldI = dyn_cast<Instruction>(const_cast<Value >(VT.first));
3310	if (!OldI)
3311	continue;
3312	auto *NewI = cast<Instruction>(VT.second);
3313	// Scan all uses of this instruction to see if it is used outside of its
3314	// funclet, and if so, record them in UsesToRename.
3315	for (Use &U : OldI->uses()) {
3316	Instruction *UserI = cast<Instruction>(U.getUser());
3317	BasicBlock *UserBB = UserI->getParent();
3318	std::set<BasicBlock *> &ColorsForUserBB = BlockColors[UserBB];
3319	assert(!ColorsForUserBB.empty())((!ColorsForUserBB.empty()) ? static_cast<void> (0) : __assert_fail ("!ColorsForUserBB.empty()", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 3319, __PRETTY_FUNCTION__));
3320	if (ColorsForUserBB.size() > 1 \|\|
3321	*ColorsForUserBB.begin() != FuncletPadBB)
3322	UsesToRename.push_back(&U);
3323	}
3324
3325	// If there are no uses outside the block, we're done with this
3326	// instruction.
3327	if (UsesToRename.empty())
3328	continue;
3329
3330	// We found a use of OldI outside of the funclet. Rename all uses of OldI
3331	// that are outside its funclet to be uses of the appropriate PHI node
3332	// etc.
3333	SSAUpdater SSAUpdate;
3334	SSAUpdate.Initialize(OldI->getType(), OldI->getName());
3335	SSAUpdate.AddAvailableValue(OldI->getParent(), OldI);
3336	SSAUpdate.AddAvailableValue(NewI->getParent(), NewI);
3337
3338	while (!UsesToRename.empty())
3339	SSAUpdate.RewriteUseAfterInsertions(*UsesToRename.pop_back_val());
3340	}
3341	}
3342	}
3343
3344	void WinEHPrepare::removeImplausibleTerminators(Function &F) {
3345	// Remove implausible terminators and replace them with UnreachableInst.
3346	for (auto &Funclet : FuncletBlocks) {
3347	BasicBlock *FuncletPadBB = Funclet.first;
3348	std::set<BasicBlock *> &BlocksInFunclet = Funclet.second;
3349	Instruction *FirstNonPHI = FuncletPadBB->getFirstNonPHI();
3350	auto *CatchPad = dyn_cast<CatchPadInst>(FirstNonPHI);
3351	auto *CleanupPad = dyn_cast<CleanupPadInst>(FirstNonPHI);
3352
3353	for (BasicBlock *BB : BlocksInFunclet) {
3354	TerminatorInst *TI = BB->getTerminator();
3355	// CatchPadInst and CleanupPadInst can't transfer control to a ReturnInst.
3356	bool IsUnreachableRet = isa<ReturnInst>(TI) && (CatchPad \|\| CleanupPad);
3357	// The token consumed by a CatchReturnInst must match the funclet token.
3358	bool IsUnreachableCatchret = false;
3359	if (auto *CRI = dyn_cast<CatchReturnInst>(TI))
3360	IsUnreachableCatchret = CRI->getCatchPad() != CatchPad;
3361	// The token consumed by a CleanupReturnInst must match the funclet token.
3362	bool IsUnreachableCleanupret = false;
3363	if (auto *CRI = dyn_cast<CleanupReturnInst>(TI))
3364	IsUnreachableCleanupret = CRI->getCleanupPad() != CleanupPad;
3365	// The token consumed by a CleanupEndPadInst must match the funclet token.
3366	bool IsUnreachableCleanupendpad = false;
3367	if (auto *CEPI = dyn_cast<CleanupEndPadInst>(TI))
3368	IsUnreachableCleanupendpad = CEPI->getCleanupPad() != CleanupPad;
3369	if (IsUnreachableRet \|\| IsUnreachableCatchret \|\|
3370	IsUnreachableCleanupret \|\| IsUnreachableCleanupendpad) {
3371	// Loop through all of our successors and make sure they know that one
3372	// of their predecessors is going away.
3373	for (BasicBlock *SuccBB : TI->successors())
3374	SuccBB->removePredecessor(BB);
3375
3376	if (IsUnreachableCleanupendpad) {
3377	// We can't simply replace a cleanupendpad with unreachable, because
3378	// its predecessor edges are EH edges and unreachable is not an EH
3379	// pad. Change all predecessors to the "unwind to caller" form.
3380	for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB);
3381	PI != PE;) {
3382	BasicBlock Pred = PI++;
3383	removeUnwindEdge(Pred);
3384	}
3385	}
3386
3387	new UnreachableInst(BB->getContext(), TI);
3388	TI->eraseFromParent();
3389	}
3390	// FIXME: Check for invokes/cleanuprets/cleanupendpads which unwind to
3391	// implausible catchendpads (i.e. catchendpad not in immediate parent
3392	// funclet).
3393	}
3394	}
3395	}
3396
3397	void WinEHPrepare::cleanupPreparedFunclets(Function &F) {
3398	// Clean-up some of the mess we made by removing useles PHI nodes, trivial
3399	// branches, etc.
3400	for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE;) {
3401	BasicBlock *BB = FI++;
3402	SimplifyInstructionsInBlock(BB);
3403	ConstantFoldTerminator(BB, /DeleteDeadConditions=/true);
3404	MergeBlockIntoPredecessor(BB);
3405	}
3406
3407	// We might have some unreachable blocks after cleaning up some impossible
3408	// control flow.
3409	removeUnreachableBlocks(F);
3410	}
3411
3412	void WinEHPrepare::verifyPreparedFunclets(Function &F) {
3413	// Recolor the CFG to verify that all is well.
3414	for (BasicBlock &BB : F) {
3415	size_t NumColors = BlockColors[&BB].size();
3416	assert(NumColors == 1 && "Expected monochromatic BB!")((NumColors == 1 && "Expected monochromatic BB!") ? static_cast <void> (0) : __assert_fail ("NumColors == 1 && \"Expected monochromatic BB!\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 3416, __PRETTY_FUNCTION__));
3417	if (NumColors == 0)
3418	report_fatal_error("Uncolored BB!");
3419	if (NumColors > 1)
3420	report_fatal_error("Multicolor BB!");
3421	if (!DisableDemotion) {
3422	bool EHPadHasPHI = BB.isEHPad() && isa<PHINode>(BB.begin());
3423	assert(!EHPadHasPHI && "EH Pad still has a PHI!")((!EHPadHasPHI && "EH Pad still has a PHI!") ? static_cast <void> (0) : __assert_fail ("!EHPadHasPHI && \"EH Pad still has a PHI!\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 3423, __PRETTY_FUNCTION__));
3424	if (EHPadHasPHI)
3425	report_fatal_error("EH Pad still has a PHI!");
3426	}
3427	}
3428	}
3429
3430	bool WinEHPrepare::prepareExplicitEH(
3431	Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks) {
3432	replaceTerminatePadWithCleanup(F);
3433
3434	// Determine which blocks are reachable from which funclet entries.
3435	colorFunclets(F, EntryBlocks);
3436
3437	if (!DisableDemotion) {
3438	demotePHIsOnFunclets(F);
3439
3440	demoteUsesBetweenFunclets(F);
3441
3442	demoteArgumentUses(F);
3443	}
3444
3445	cloneCommonBlocks(F, EntryBlocks);
3446
3447	if (!DisableCleanups) {
3448	removeImplausibleTerminators(F);
3449
3450	cleanupPreparedFunclets(F);
3451	}
3452
3453	verifyPreparedFunclets(F);
3454
3455	BlockColors.clear();
3456	FuncletBlocks.clear();
3457	FuncletChildren.clear();
3458
3459	return true;
3460	}
3461
3462	// TODO: Share loads when one use dominates another, or when a catchpad exit
3463	// dominates uses (needs dominators).
3464	AllocaInst WinEHPrepare::insertPHILoads(PHINode PN, Function &F) {
3465	BasicBlock *PHIBlock = PN->getParent();
3466	AllocaInst *SpillSlot = nullptr;
3467
3468	if (isa<CleanupPadInst>(PHIBlock->getFirstNonPHI())) {
3469	// Insert a load in place of the PHI and replace all uses.
3470	SpillSlot = new AllocaInst(PN->getType(), nullptr,
3471	Twine(PN->getName(), ".wineh.spillslot"),
3472	F.getEntryBlock().begin());
3473	Value *V = new LoadInst(SpillSlot, Twine(PN->getName(), ".wineh.reload"),
3474	PHIBlock->getFirstInsertionPt());
3475	PN->replaceAllUsesWith(V);
3476	return SpillSlot;
3477	}
3478
3479	DenseMap<BasicBlock , Value > Loads;
3480	for (Value::use_iterator UI = PN->use_begin(), UE = PN->use_end();
3481	UI != UE;) {
3482	Use &U = *UI++;
3483	auto *UsingInst = cast<Instruction>(U.getUser());
3484	BasicBlock *UsingBB = UsingInst->getParent();
3485	if (UsingBB->isEHPad()) {
3486	// Use is on an EH pad phi. Leave it alone; we'll insert loads and
3487	// stores for it separately.
3488	assert(isa<PHINode>(UsingInst))((isa<PHINode>(UsingInst)) ? static_cast<void> (0 ) : __assert_fail ("isa<PHINode>(UsingInst)", "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 3488, __PRETTY_FUNCTION__));
3489	continue;
3490	}
3491	replaceUseWithLoad(PN, U, SpillSlot, Loads, F);
3492	}
3493	return SpillSlot;
3494	}
3495
3496	// TODO: improve store placement. Inserting at def is probably good, but need
3497	// to be careful not to introduce interfering stores (needs liveness analysis).
3498	// TODO: identify related phi nodes that can share spill slots, and share them
3499	// (also needs liveness).
3500	void WinEHPrepare::insertPHIStores(PHINode *OriginalPHI,
3501	AllocaInst *SpillSlot) {
3502	// Use a worklist of (Block, Value) pairs -- the given Value needs to be
3503	// stored to the spill slot by the end of the given Block.
3504	SmallVector<std::pair<BasicBlock , Value >, 4> Worklist;
3505
3506	Worklist.push_back({OriginalPHI->getParent(), OriginalPHI});
3507
3508	while (!Worklist.empty()) {
3509	BasicBlock *EHBlock;
3510	Value *InVal;
3511	std::tie(EHBlock, InVal) = Worklist.pop_back_val();
3512
3513	PHINode *PN = dyn_cast<PHINode>(InVal);
3514	if (PN && PN->getParent() == EHBlock) {
3515	// The value is defined by another PHI we need to remove, with no room to
3516	// insert a store after the PHI, so each predecessor needs to store its
3517	// incoming value.
3518	for (unsigned i = 0, e = PN->getNumIncomingValues(); i < e; ++i) {
3519	Value *PredVal = PN->getIncomingValue(i);
3520
3521	// Undef can safely be skipped.
3522	if (isa<UndefValue>(PredVal))
3523	continue;
3524
3525	insertPHIStore(PN->getIncomingBlock(i), PredVal, SpillSlot, Worklist);
3526	}
3527	} else {
3528	// We need to store InVal, which dominates EHBlock, but can't put a store
3529	// in EHBlock, so need to put stores in each predecessor.
3530	for (BasicBlock *PredBlock : predecessors(EHBlock)) {
3531	insertPHIStore(PredBlock, InVal, SpillSlot, Worklist);
3532	}
3533	}
3534	}
3535	}
3536
3537	void WinEHPrepare::insertPHIStore(
3538	BasicBlock PredBlock, Value PredVal, AllocaInst *SpillSlot,
3539	SmallVectorImpl<std::pair<BasicBlock , Value >> &Worklist) {
3540
3541	if (PredBlock->isEHPad() &&
3542	!isa<CleanupPadInst>(PredBlock->getFirstNonPHI())) {
3543	// Pred is unsplittable, so we need to queue it on the worklist.
3544	Worklist.push_back({PredBlock, PredVal});
3545	return;
3546	}
3547
3548	// Otherwise, insert the store at the end of the basic block.
3549	new StoreInst(PredVal, SpillSlot, PredBlock->getTerminator());
3550	}
3551
3552	// TODO: Share loads for same-funclet uses (requires dominators if funclets
3553	// aren't properly nested).
3554	void WinEHPrepare::demoteNonlocalUses(Value *V,
3555	std::set<BasicBlock *> &ColorsForBB,
3556	Function &F) {
3557	// Tokens can only be used non-locally due to control flow involving
3558	// unreachable edges. Don't try to demote the token usage, we'll simply
3559	// delete the cloned user later.
3560	if (isa<CatchPadInst>(V) \|\| isa<CleanupPadInst>(V))
3561	return;
3562
3563	DenseMap<BasicBlock , Value > Loads;
3564	AllocaInst *SpillSlot = nullptr;
3565	for (Value::use_iterator UI = V->use_begin(), UE = V->use_end(); UI != UE;) {
3566	Use &U = *UI++;
3567	auto *UsingInst = cast<Instruction>(U.getUser());
3568	BasicBlock *UsingBB = UsingInst->getParent();
3569
3570	// Is the Use inside a block which is colored the same as the Def?
3571	// If so, we don't need to escape the Def because we will clone
3572	// ourselves our own private copy.
3573	std::set<BasicBlock *> &ColorsForUsingBB = BlockColors[UsingBB];
3574	if (ColorsForUsingBB == ColorsForBB)
3575	continue;
3576
3577	replaceUseWithLoad(V, U, SpillSlot, Loads, F);
3578	}
3579	if (SpillSlot) {
3580	// Insert stores of the computed value into the stack slot.
3581	// We have to be careful if I is an invoke instruction,
3582	// because we can't insert the store AFTER the terminator instruction.
3583	BasicBlock::iterator InsertPt;
3584	if (isa<Argument>(V)) {
3585	InsertPt = F.getEntryBlock().getTerminator();
3586	} else if (isa<TerminatorInst>(V)) {
3587	auto *II = cast<InvokeInst>(V);
3588	// We cannot demote invoke instructions to the stack if their normal
3589	// edge is critical. Therefore, split the critical edge and create a
3590	// basic block into which the store can be inserted.
3591	if (!II->getNormalDest()->getSinglePredecessor()) {
3592	unsigned SuccNum =
3593	GetSuccessorNumber(II->getParent(), II->getNormalDest());
3594	assert(isCriticalEdge(II, SuccNum) && "Expected a critical edge!")((isCriticalEdge(II, SuccNum) && "Expected a critical edge!" ) ? static_cast<void> (0) : __assert_fail ("isCriticalEdge(II, SuccNum) && \"Expected a critical edge!\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 3594, __PRETTY_FUNCTION__));
3595	BasicBlock *NewBlock = SplitCriticalEdge(II, SuccNum);
3596	assert(NewBlock && "Unable to split critical edge.")((NewBlock && "Unable to split critical edge.") ? static_cast <void> (0) : __assert_fail ("NewBlock && \"Unable to split critical edge.\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 3596, __PRETTY_FUNCTION__));
3597	// Update the color mapping for the newly split edge.
3598	std::set<BasicBlock *> &ColorsForUsingBB = BlockColors[II->getParent()];
3599	BlockColors[NewBlock] = ColorsForUsingBB;
3600	for (BasicBlock *FuncletPad : ColorsForUsingBB)
3601	FuncletBlocks[FuncletPad].insert(NewBlock);
3602	}
3603	InsertPt = II->getNormalDest()->getFirstInsertionPt();
3604	} else {
3605	InsertPt = cast<Instruction>(V);
3606	++InsertPt;
3607	// Don't insert before PHI nodes or EH pad instrs.
3608	for (; isa<PHINode>(InsertPt) \|\| InsertPt->isEHPad(); ++InsertPt)
3609	;
3610	}
3611	new StoreInst(V, SpillSlot, InsertPt);
3612	}
3613	}
3614
3615	void WinEHPrepare::replaceUseWithLoad(Value V, Use &U, AllocaInst &SpillSlot,
3616	DenseMap<BasicBlock , Value > &Loads,
3617	Function &F) {
3618	// Lazilly create the spill slot.
3619	if (!SpillSlot)
3620	SpillSlot = new AllocaInst(V->getType(), nullptr,
3621	Twine(V->getName(), ".wineh.spillslot"),
3622	F.getEntryBlock().begin());
3623
3624	auto *UsingInst = cast<Instruction>(U.getUser());
3625	if (auto *UsingPHI = dyn_cast<PHINode>(UsingInst)) {
3626	// If this is a PHI node, we can't insert a load of the value before
3627	// the use. Instead insert the load in the predecessor block
3628	// corresponding to the incoming value.
3629	//
3630	// Note that if there are multiple edges from a basic block to this
3631	// PHI node that we cannot have multiple loads. The problem is that
3632	// the resulting PHI node will have multiple values (from each load)
3633	// coming in from the same block, which is illegal SSA form.
3634	// For this reason, we keep track of and reuse loads we insert.
3635	BasicBlock *IncomingBlock = UsingPHI->getIncomingBlock(U);
3636	if (auto *CatchRet =
3637	dyn_cast<CatchReturnInst>(IncomingBlock->getTerminator())) {
3638	// Putting a load above a catchret and use on the phi would still leave
3639	// a cross-funclet def/use. We need to split the edge, change the
3640	// catchret to target the new block, and put the load there.
3641	BasicBlock *PHIBlock = UsingInst->getParent();
3642	BasicBlock *NewBlock = SplitEdge(IncomingBlock, PHIBlock);
3643	// SplitEdge gives us:
3644	// IncomingBlock:
3645	// ...
3646	// br label %NewBlock
3647	// NewBlock:
3648	// catchret label %PHIBlock
3649	// But we need:
3650	// IncomingBlock:
3651	// ...
3652	// catchret label %NewBlock
3653	// NewBlock:
3654	// br label %PHIBlock
3655	// So move the terminators to each others' blocks and swap their
3656	// successors.
3657	BranchInst *Goto = cast<BranchInst>(IncomingBlock->getTerminator());
3658	Goto->removeFromParent();
3659	CatchRet->removeFromParent();
3660	IncomingBlock->getInstList().push_back(CatchRet);
3661	NewBlock->getInstList().push_back(Goto);
3662	Goto->setSuccessor(0, PHIBlock);
3663	CatchRet->setSuccessor(NewBlock);
3664	// Update the color mapping for the newly split edge.
3665	std::set<BasicBlock *> &ColorsForPHIBlock = BlockColors[PHIBlock];
3666	BlockColors[NewBlock] = ColorsForPHIBlock;
3667	for (BasicBlock *FuncletPad : ColorsForPHIBlock)
3668	FuncletBlocks[FuncletPad].insert(NewBlock);
3669	// Treat the new block as incoming for load insertion.
3670	IncomingBlock = NewBlock;
3671	}
3672	Value *&Load = Loads[IncomingBlock];
3673	// Insert the load into the predecessor block
3674	if (!Load)
3675	Load = new LoadInst(SpillSlot, Twine(V->getName(), ".wineh.reload"),
3676	/Volatile=/false, IncomingBlock->getTerminator());
3677
3678	U.set(Load);
3679	} else {
3680	// Reload right before the old use.
3681	auto *Load = new LoadInst(SpillSlot, Twine(V->getName(), ".wineh.reload"),
3682	/Volatile=/false, UsingInst);
3683	U.set(Load);
3684	}
3685	}
3686
3687	void WinEHFuncInfo::addIPToStateRange(const BasicBlock *PadBB,
3688	MCSymbol *InvokeBegin,
3689	MCSymbol *InvokeEnd) {
3690	assert(PadBB->isEHPad() && EHPadStateMap.count(PadBB->getFirstNonPHI()) &&((PadBB->isEHPad() && EHPadStateMap.count(PadBB-> getFirstNonPHI()) && "should get EH pad BB with precomputed state" ) ? static_cast<void> (0) : __assert_fail ("PadBB->isEHPad() && EHPadStateMap.count(PadBB->getFirstNonPHI()) && \"should get EH pad BB with precomputed state\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 3691, __PRETTY_FUNCTION__))
3691	"should get EH pad BB with precomputed state")((PadBB->isEHPad() && EHPadStateMap.count(PadBB-> getFirstNonPHI()) && "should get EH pad BB with precomputed state" ) ? static_cast<void> (0) : __assert_fail ("PadBB->isEHPad() && EHPadStateMap.count(PadBB->getFirstNonPHI()) && \"should get EH pad BB with precomputed state\"" , "/tmp/buildd/llvm-toolchain-snapshot-3.8~svn249890/lib/CodeGen/WinEHPrepare.cpp" , 3691, __PRETTY_FUNCTION__));
3692	InvokeToStateMap[InvokeBegin] =
3693	std::make_pair(EHPadStateMap[PadBB->getFirstNonPHI()], InvokeEnd);
3694	}