Line data Source code
1 : //===- CodeGen/AsmPrinter/EHStreamer.cpp - Exception Directive Streamer ---===//
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 file contains support for writing exception info into assembly files.
11 : //
12 : //===----------------------------------------------------------------------===//
13 :
14 : #include "EHStreamer.h"
15 : #include "llvm/ADT/SmallVector.h"
16 : #include "llvm/ADT/Twine.h"
17 : #include "llvm/ADT/iterator_range.h"
18 : #include "llvm/BinaryFormat/Dwarf.h"
19 : #include "llvm/CodeGen/AsmPrinter.h"
20 : #include "llvm/CodeGen/MachineFunction.h"
21 : #include "llvm/CodeGen/MachineInstr.h"
22 : #include "llvm/CodeGen/MachineOperand.h"
23 : #include "llvm/IR/DataLayout.h"
24 : #include "llvm/IR/Function.h"
25 : #include "llvm/MC/MCAsmInfo.h"
26 : #include "llvm/MC/MCContext.h"
27 : #include "llvm/MC/MCStreamer.h"
28 : #include "llvm/MC/MCSymbol.h"
29 : #include "llvm/MC/MCTargetOptions.h"
30 : #include "llvm/Support/Casting.h"
31 : #include "llvm/Support/LEB128.h"
32 : #include "llvm/Target/TargetLoweringObjectFile.h"
33 : #include <algorithm>
34 : #include <cassert>
35 : #include <cstdint>
36 : #include <vector>
37 :
38 : using namespace llvm;
39 :
40 24288 : EHStreamer::EHStreamer(AsmPrinter *A) : Asm(A), MMI(Asm->MMI) {}
41 :
42 : EHStreamer::~EHStreamer() = default;
43 :
44 : /// How many leading type ids two landing pads have in common.
45 0 : unsigned EHStreamer::sharedTypeIDs(const LandingPadInfo *L,
46 : const LandingPadInfo *R) {
47 : const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
48 582788 : unsigned LSize = LIds.size(), RSize = RIds.size();
49 291394 : unsigned MinSize = LSize < RSize ? LSize : RSize;
50 : unsigned Count = 0;
51 :
52 376780 : for (; Count != MinSize; ++Count)
53 259842 : if (LIds[Count] != RIds[Count])
54 0 : return Count;
55 :
56 : return Count;
57 : }
58 :
59 : /// Compute the actions table and gather the first action index for each landing
60 : /// pad site.
61 46780 : void EHStreamer::computeActionsTable(
62 : const SmallVectorImpl<const LandingPadInfo *> &LandingPads,
63 : SmallVectorImpl<ActionEntry> &Actions,
64 : SmallVectorImpl<unsigned> &FirstActions) {
65 : // The action table follows the call-site table in the LSDA. The individual
66 : // records are of two types:
67 : //
68 : // * Catch clause
69 : // * Exception specification
70 : //
71 : // The two record kinds have the same format, with only small differences.
72 : // They are distinguished by the "switch value" field: Catch clauses
73 : // (TypeInfos) have strictly positive switch values, and exception
74 : // specifications (FilterIds) have strictly negative switch values. Value 0
75 : // indicates a catch-all clause.
76 : //
77 : // Negative type IDs index into FilterIds. Positive type IDs index into
78 : // TypeInfos. The value written for a positive type ID is just the type ID
79 : // itself. For a negative type ID, however, the value written is the
80 : // (negative) byte offset of the corresponding FilterIds entry. The byte
81 : // offset is usually equal to the type ID (because the FilterIds entries are
82 : // written using a variable width encoding, which outputs one byte per entry
83 : // as long as the value written is not too large) but can differ. This kind
84 : // of complication does not occur for positive type IDs because type infos are
85 : // output using a fixed width encoding. FilterOffsets[i] holds the byte
86 : // offset corresponding to FilterIds[i].
87 :
88 46780 : const std::vector<unsigned> &FilterIds = Asm->MF->getFilterIds();
89 : SmallVector<int, 16> FilterOffsets;
90 46780 : FilterOffsets.reserve(FilterIds.size());
91 46780 : int Offset = -1;
92 :
93 : for (std::vector<unsigned>::const_iterator
94 47725 : I = FilterIds.begin(), E = FilterIds.end(); I != E; ++I) {
95 945 : FilterOffsets.push_back(Offset);
96 945 : Offset -= getULEB128Size(*I);
97 : }
98 :
99 46780 : FirstActions.reserve(LandingPads.size());
100 :
101 : int FirstAction = 0;
102 : unsigned SizeActions = 0; // Total size of all action entries for a function
103 : const LandingPadInfo *PrevLPI = nullptr;
104 :
105 338167 : for (SmallVectorImpl<const LandingPadInfo *>::const_iterator
106 384947 : I = LandingPads.begin(), E = LandingPads.end(); I != E; ++I) {
107 338167 : const LandingPadInfo *LPI = *I;
108 : const std::vector<int> &TypeIds = LPI->TypeIds;
109 338167 : unsigned NumShared = PrevLPI ? sharedTypeIDs(LPI, PrevLPI) : 0;
110 : unsigned SizeSiteActions = 0; // Total size of all entries for a landingpad
111 :
112 676334 : if (NumShared < TypeIds.size()) {
113 : // Size of one action entry (typeid + next action)
114 : unsigned SizeActionEntry = 0;
115 : unsigned PrevAction = (unsigned)-1;
116 :
117 38330 : if (NumShared) {
118 10722 : unsigned SizePrevIds = PrevLPI->TypeIds.size();
119 : assert(Actions.size());
120 10722 : PrevAction = Actions.size() - 1;
121 32166 : SizeActionEntry = getSLEB128Size(Actions[PrevAction].NextAction) +
122 10722 : getSLEB128Size(Actions[PrevAction].ValueForTypeID);
123 :
124 10814 : for (unsigned j = NumShared; j != SizePrevIds; ++j) {
125 : assert(PrevAction != (unsigned)-1 && "PrevAction is invalid!");
126 184 : SizeActionEntry -= getSLEB128Size(Actions[PrevAction].ValueForTypeID);
127 92 : SizeActionEntry += -Actions[PrevAction].NextAction;
128 92 : PrevAction = Actions[PrevAction].Previous;
129 : }
130 : }
131 :
132 : // Compute the actions.
133 116875 : for (unsigned J = NumShared, M = TypeIds.size(); J != M; ++J) {
134 40215 : int TypeID = TypeIds[J];
135 : assert(-1 - TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
136 : int ValueForTypeID =
137 40215 : isFilterEHSelector(TypeID) ? FilterOffsets[-1 - TypeID] : TypeID;
138 40215 : unsigned SizeTypeID = getSLEB128Size(ValueForTypeID);
139 :
140 40215 : int NextAction = SizeActionEntry ? -(SizeActionEntry + SizeTypeID) : 0;
141 40215 : SizeActionEntry = SizeTypeID + getSLEB128Size(NextAction);
142 40215 : SizeSiteActions += SizeActionEntry;
143 :
144 40215 : ActionEntry Action = { ValueForTypeID, NextAction, PrevAction };
145 40215 : Actions.push_back(Action);
146 40215 : PrevAction = Actions.size() - 1;
147 : }
148 :
149 : // Record the first action of the landing pad site.
150 38330 : FirstAction = SizeActions + SizeSiteActions - SizeActionEntry + 1;
151 : } // else identical - re-use previous FirstAction
152 :
153 : // Information used when creating the call-site table. The action record
154 : // field of the call site record is the offset of the first associated
155 : // action record, relative to the start of the actions table. This value is
156 : // biased by 1 (1 indicating the start of the actions table), and 0
157 : // indicates that there are no actions.
158 338167 : FirstActions.push_back(FirstAction);
159 :
160 : // Compute this sites contribution to size.
161 338167 : SizeActions += SizeSiteActions;
162 :
163 : PrevLPI = LPI;
164 : }
165 46780 : }
166 :
167 : /// Return `true' if this is a call to a function marked `nounwind'. Return
168 : /// `false' otherwise.
169 1693409 : bool EHStreamer::callToNoUnwindFunction(const MachineInstr *MI) {
170 : assert(MI->isCall() && "This should be a call instruction!");
171 :
172 : bool MarkedNoUnwind = false;
173 : bool SawFunc = false;
174 :
175 14006555 : for (unsigned I = 0, E = MI->getNumOperands(); I != E; ++I) {
176 12313146 : const MachineOperand &MO = MI->getOperand(I);
177 :
178 12313146 : if (!MO.isGlobal()) continue;
179 :
180 1631448 : const Function *F = dyn_cast<Function>(MO.getGlobal());
181 : if (!F) continue;
182 :
183 1631420 : if (SawFunc) {
184 : // Be conservative. If we have more than one function operand for this
185 : // call, then we can't make the assumption that it's the callee and
186 : // not a parameter to the call.
187 : //
188 : // FIXME: Determine if there's a way to say that `F' is the callee or
189 : // parameter.
190 : MarkedNoUnwind = false;
191 : break;
192 : }
193 :
194 : MarkedNoUnwind = F->doesNotThrow();
195 : SawFunc = true;
196 : }
197 :
198 1693409 : return MarkedNoUnwind;
199 : }
200 :
201 46780 : void EHStreamer::computePadMap(
202 : const SmallVectorImpl<const LandingPadInfo *> &LandingPads,
203 : RangeMapType &PadMap) {
204 : // Invokes and nounwind calls have entries in PadMap (due to being bracketed
205 : // by try-range labels when lowered). Ordinary calls do not, so appropriate
206 : // try-ranges for them need be deduced so we can put them in the LSDA.
207 384947 : for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
208 338167 : const LandingPadInfo *LandingPad = LandingPads[i];
209 834979 : for (unsigned j = 0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
210 993624 : MCSymbol *BeginLabel = LandingPad->BeginLabels[j];
211 : assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
212 : PadRange P = { i, j };
213 496812 : PadMap[BeginLabel] = P;
214 : }
215 : }
216 46780 : }
217 :
218 : /// Compute the call-site table. The entry for an invoke has a try-range
219 : /// containing the call, a non-zero landing pad, and an appropriate action. The
220 : /// entry for an ordinary call has a try-range containing the call and zero for
221 : /// the landing pad and the action. Calls marked 'nounwind' have no entry and
222 : /// must not be contained in the try-range of any entry - they form gaps in the
223 : /// table. Entries must be ordered by try-range address.
224 46780 : void EHStreamer::
225 : computeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
226 : const SmallVectorImpl<const LandingPadInfo *> &LandingPads,
227 : const SmallVectorImpl<unsigned> &FirstActions) {
228 : RangeMapType PadMap;
229 46780 : computePadMap(LandingPads, PadMap);
230 :
231 : // The end label of the previous invoke or nounwind try-range.
232 : MCSymbol *LastLabel = nullptr;
233 :
234 : // Whether there is a potentially throwing instruction (currently this means
235 : // an ordinary call) between the end of the previous try-range and now.
236 : bool SawPotentiallyThrowing = false;
237 :
238 : // Whether the last CallSite entry was for an invoke.
239 : bool PreviousIsInvoke = false;
240 :
241 46780 : bool IsSJLJ = Asm->MAI->getExceptionHandlingType() == ExceptionHandling::SjLj;
242 :
243 : // Visit all instructions in order of address.
244 2278609 : for (const auto &MBB : *Asm->MF) {
245 25620684 : for (const auto &MI : MBB) {
246 23388855 : if (!MI.isEHLabel()) {
247 22057062 : if (MI.isCall())
248 1693392 : SawPotentiallyThrowing |= !callToNoUnwindFunction(&MI);
249 22057062 : continue;
250 : }
251 :
252 : // End of the previous try-range?
253 1331793 : MCSymbol *BeginLabel = MI.getOperand(0).getMCSymbol();
254 1331793 : if (BeginLabel == LastLabel)
255 : SawPotentiallyThrowing = false;
256 :
257 : // Beginning of a new try-range?
258 1331793 : RangeMapType::const_iterator L = PadMap.find(BeginLabel);
259 1331793 : if (L == PadMap.end())
260 : // Nope, it was just some random label.
261 : continue;
262 :
263 : const PadRange &P = L->second;
264 496812 : const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
265 : assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
266 : "Inconsistent landing pad map!");
267 :
268 : // For Dwarf exception handling (SjLj handling doesn't use this). If some
269 : // instruction between the previous try-range and this one may throw,
270 : // create a call-site entry with no landing pad for the region between the
271 : // try-ranges.
272 496812 : if (SawPotentiallyThrowing && Asm->MAI->usesCFIForEH()) {
273 164118 : CallSiteEntry Site = { LastLabel, BeginLabel, nullptr, 0 };
274 164118 : CallSites.push_back(Site);
275 : PreviousIsInvoke = false;
276 : }
277 :
278 496812 : LastLabel = LandingPad->EndLabels[P.RangeIndex];
279 : assert(BeginLabel && LastLabel && "Invalid landing pad!");
280 :
281 496812 : if (!LandingPad->LandingPadLabel) {
282 : // Create a gap.
283 : PreviousIsInvoke = false;
284 : } else {
285 : // This try-range is for an invoke.
286 : CallSiteEntry Site = {
287 : BeginLabel,
288 : LastLabel,
289 : LandingPad,
290 496812 : FirstActions[P.PadIndex]
291 496812 : };
292 :
293 : // Try to merge with the previous call-site. SJLJ doesn't do this
294 496812 : if (PreviousIsInvoke && !IsSJLJ) {
295 : CallSiteEntry &Prev = CallSites.back();
296 319024 : if (Site.LPad == Prev.LPad && Site.Action == Prev.Action) {
297 : // Extend the range of the previous entry.
298 138121 : Prev.EndLabel = Site.EndLabel;
299 138121 : continue;
300 : }
301 : }
302 :
303 : // Otherwise, create a new call-site.
304 358691 : if (!IsSJLJ)
305 358516 : CallSites.push_back(Site);
306 : else {
307 : // SjLj EH must maintain the call sites in the order assigned
308 : // to them by the SjLjPrepare pass.
309 175 : unsigned SiteNo = Asm->MF->getCallSiteBeginLabel(BeginLabel);
310 175 : if (CallSites.size() < SiteNo)
311 140 : CallSites.resize(SiteNo);
312 350 : CallSites[SiteNo - 1] = Site;
313 : }
314 : PreviousIsInvoke = true;
315 : }
316 : }
317 : }
318 :
319 : // If some instruction between the previous try-range and the end of the
320 : // function may throw, create a call-site entry with no landing pad for the
321 : // region following the try-range.
322 46780 : if (SawPotentiallyThrowing && !IsSJLJ) {
323 40355 : CallSiteEntry Site = { LastLabel, nullptr, nullptr, 0 };
324 40355 : CallSites.push_back(Site);
325 : }
326 46780 : }
327 :
328 : /// Emit landing pads and actions.
329 : ///
330 : /// The general organization of the table is complex, but the basic concepts are
331 : /// easy. First there is a header which describes the location and organization
332 : /// of the three components that follow.
333 : ///
334 : /// 1. The landing pad site information describes the range of code covered by
335 : /// the try. In our case it's an accumulation of the ranges covered by the
336 : /// invokes in the try. There is also a reference to the landing pad that
337 : /// handles the exception once processed. Finally an index into the actions
338 : /// table.
339 : /// 2. The action table, in our case, is composed of pairs of type IDs and next
340 : /// action offset. Starting with the action index from the landing pad
341 : /// site, each type ID is checked for a match to the current exception. If
342 : /// it matches then the exception and type id are passed on to the landing
343 : /// pad. Otherwise the next action is looked up. This chain is terminated
344 : /// with a next action of zero. If no type id is found then the frame is
345 : /// unwound and handling continues.
346 : /// 3. Type ID table contains references to all the C++ typeinfo for all
347 : /// catches in the function. This tables is reverse indexed base 1.
348 46780 : void EHStreamer::emitExceptionTable() {
349 46780 : const MachineFunction *MF = Asm->MF;
350 : const std::vector<const GlobalValue *> &TypeInfos = MF->getTypeInfos();
351 : const std::vector<unsigned> &FilterIds = MF->getFilterIds();
352 : const std::vector<LandingPadInfo> &PadInfos = MF->getLandingPads();
353 :
354 : // Sort the landing pads in order of their type ids. This is used to fold
355 : // duplicate actions.
356 : SmallVector<const LandingPadInfo *, 64> LandingPads;
357 46780 : LandingPads.reserve(PadInfos.size());
358 :
359 431727 : for (unsigned i = 0, N = PadInfos.size(); i != N; ++i)
360 676334 : LandingPads.push_back(&PadInfos[i]);
361 :
362 : // Order landing pads lexicographically by type id.
363 : llvm::sort(LandingPads, [](const LandingPadInfo *L, const LandingPadInfo *R) {
364 : return L->TypeIds < R->TypeIds;
365 : });
366 :
367 : // Compute the actions table and gather the first action index for each
368 : // landing pad site.
369 : SmallVector<ActionEntry, 32> Actions;
370 : SmallVector<unsigned, 64> FirstActions;
371 46780 : computeActionsTable(LandingPads, Actions, FirstActions);
372 :
373 : // Compute the call-site table.
374 : SmallVector<CallSiteEntry, 64> CallSites;
375 46780 : computeCallSiteTable(CallSites, LandingPads, FirstActions);
376 :
377 46780 : bool IsSJLJ = Asm->MAI->getExceptionHandlingType() == ExceptionHandling::SjLj;
378 : unsigned CallSiteEncoding =
379 46780 : IsSJLJ ? dwarf::DW_EH_PE_udata4 : dwarf::DW_EH_PE_uleb128;
380 46780 : bool HaveTTData = !TypeInfos.empty() || !FilterIds.empty();
381 :
382 : // Type infos.
383 46780 : MCSection *LSDASection = Asm->getObjFileLowering().getLSDASection();
384 : unsigned TTypeEncoding;
385 :
386 46780 : if (!HaveTTData) {
387 : // If there is no TypeInfo, then we just explicitly say that we're omitting
388 : // that bit.
389 : TTypeEncoding = dwarf::DW_EH_PE_omit;
390 : } else {
391 : // Okay, we have actual filters or typeinfos to emit. As such, we need to
392 : // pick a type encoding for them. We're about to emit a list of pointers to
393 : // typeinfo objects at the end of the LSDA. However, unless we're in static
394 : // mode, this reference will require a relocation by the dynamic linker.
395 : //
396 : // Because of this, we have a couple of options:
397 : //
398 : // 1) If we are in -static mode, we can always use an absolute reference
399 : // from the LSDA, because the static linker will resolve it.
400 : //
401 : // 2) Otherwise, if the LSDA section is writable, we can output the direct
402 : // reference to the typeinfo and allow the dynamic linker to relocate
403 : // it. Since it is in a writable section, the dynamic linker won't
404 : // have a problem.
405 : //
406 : // 3) Finally, if we're in PIC mode and the LDSA section isn't writable,
407 : // we need to use some form of indirection. For example, on Darwin,
408 : // we can output a statically-relocatable reference to a dyld stub. The
409 : // offset to the stub is constant, but the contents are in a section
410 : // that is updated by the dynamic linker. This is easy enough, but we
411 : // need to tell the personality function of the unwinder to indirect
412 : // through the dyld stub.
413 : //
414 : // FIXME: When (3) is actually implemented, we'll have to emit the stubs
415 : // somewhere. This predicate should be moved to a shared location that is
416 : // in target-independent code.
417 : //
418 26453 : TTypeEncoding = Asm->getObjFileLowering().getTTypeEncoding();
419 : }
420 :
421 : // Begin the exception table.
422 : // Sometimes we want not to emit the data into separate section (e.g. ARM
423 : // EHABI). In this case LSDASection will be NULL.
424 46780 : if (LSDASection)
425 93438 : Asm->OutStreamer->SwitchSection(LSDASection);
426 46780 : Asm->EmitAlignment(2);
427 :
428 : // Emit the LSDA.
429 : MCSymbol *GCCETSym =
430 46780 : Asm->OutContext.getOrCreateSymbol(Twine("GCC_except_table")+
431 46780 : Twine(Asm->getFunctionNumber()));
432 93560 : Asm->OutStreamer->EmitLabel(GCCETSym);
433 93560 : Asm->OutStreamer->EmitLabel(Asm->getCurExceptionSym());
434 :
435 : // Emit the LSDA header.
436 46780 : Asm->EmitEncodingByte(dwarf::DW_EH_PE_omit, "@LPStart");
437 46780 : Asm->EmitEncodingByte(TTypeEncoding, "@TType");
438 :
439 : MCSymbol *TTBaseLabel = nullptr;
440 46780 : if (HaveTTData) {
441 : // N.B.: There is a dependency loop between the size of the TTBase uleb128
442 : // here and the amount of padding before the aligned type table. The
443 : // assembler must sometimes pad this uleb128 or insert extra padding before
444 : // the type table. See PR35809 or GNU as bug 4029.
445 52906 : MCSymbol *TTBaseRefLabel = Asm->createTempSymbol("ttbaseref");
446 52906 : TTBaseLabel = Asm->createTempSymbol("ttbase");
447 26453 : Asm->EmitLabelDifferenceAsULEB128(TTBaseLabel, TTBaseRefLabel);
448 52906 : Asm->OutStreamer->EmitLabel(TTBaseRefLabel);
449 : }
450 :
451 93560 : bool VerboseAsm = Asm->OutStreamer->isVerboseAsm();
452 :
453 : // Emit the landing pad call site table.
454 93560 : MCSymbol *CstBeginLabel = Asm->createTempSymbol("cst_begin");
455 93560 : MCSymbol *CstEndLabel = Asm->createTempSymbol("cst_end");
456 46780 : Asm->EmitEncodingByte(CallSiteEncoding, "Call site");
457 46780 : Asm->EmitLabelDifferenceAsULEB128(CstEndLabel, CstBeginLabel);
458 93560 : Asm->OutStreamer->EmitLabel(CstBeginLabel);
459 :
460 : // SjLj Exception handling
461 46780 : if (IsSJLJ) {
462 : unsigned idx = 0;
463 175 : for (SmallVectorImpl<CallSiteEntry>::const_iterator
464 211 : I = CallSites.begin(), E = CallSites.end(); I != E; ++I, ++idx) {
465 : const CallSiteEntry &S = *I;
466 :
467 : // Index of the call site entry.
468 175 : if (VerboseAsm) {
469 141 : Asm->OutStreamer->AddComment(">> Call Site " + Twine(idx) + " <<");
470 94 : Asm->OutStreamer->AddComment(" On exception at call site "+Twine(idx));
471 : }
472 175 : Asm->EmitULEB128(idx);
473 :
474 : // Offset of the first associated action record, relative to the start of
475 : // the action table. This value is biased by 1 (1 indicates the start of
476 : // the action table), and 0 indicates that there are no actions.
477 175 : if (VerboseAsm) {
478 47 : if (S.Action == 0)
479 60 : Asm->OutStreamer->AddComment(" Action: cleanup");
480 : else
481 27 : Asm->OutStreamer->AddComment(" Action: " +
482 54 : Twine((S.Action - 1) / 2 + 1));
483 : }
484 175 : Asm->EmitULEB128(S.Action);
485 : }
486 : } else {
487 : // Itanium LSDA exception handling
488 :
489 : // The call-site table is a list of all call sites that may throw an
490 : // exception (including C++ 'throw' statements) in the procedure
491 : // fragment. It immediately follows the LSDA header. Each entry indicates,
492 : // for a given call, the first corresponding action record and corresponding
493 : // landing pad.
494 : //
495 : // The table begins with the number of bytes, stored as an LEB128
496 : // compressed, unsigned integer. The records immediately follow the record
497 : // count. They are sorted in increasing call-site address. Each record
498 : // indicates:
499 : //
500 : // * The position of the call-site.
501 : // * The position of the landing pad.
502 : // * The first action record for that call site.
503 : //
504 : // A missing entry in the call-site table indicates that a call is not
505 : // supposed to throw.
506 :
507 : unsigned Entry = 0;
508 562989 : for (SmallVectorImpl<CallSiteEntry>::const_iterator
509 609733 : I = CallSites.begin(), E = CallSites.end(); I != E; ++I) {
510 : const CallSiteEntry &S = *I;
511 :
512 562989 : MCSymbol *EHFuncBeginSym = Asm->getFunctionBegin();
513 :
514 562989 : MCSymbol *BeginLabel = S.BeginLabel;
515 562989 : if (!BeginLabel)
516 : BeginLabel = EHFuncBeginSym;
517 562989 : MCSymbol *EndLabel = S.EndLabel;
518 562989 : if (!EndLabel)
519 40355 : EndLabel = Asm->getFunctionEnd();
520 :
521 : // Offset of the call site relative to the start of the procedure.
522 562989 : if (VerboseAsm)
523 1836 : Asm->OutStreamer->AddComment(">> Call Site " + Twine(++Entry) + " <<");
524 562989 : Asm->EmitLabelDifferenceAsULEB128(BeginLabel, EHFuncBeginSym);
525 562989 : if (VerboseAsm)
526 1224 : Asm->OutStreamer->AddComment(Twine(" Call between ") +
527 612 : BeginLabel->getName() + " and " +
528 1836 : EndLabel->getName());
529 562989 : Asm->EmitLabelDifferenceAsULEB128(EndLabel, BeginLabel);
530 :
531 : // Offset of the landing pad relative to the start of the procedure.
532 562989 : if (!S.LPad) {
533 204473 : if (VerboseAsm)
534 693 : Asm->OutStreamer->AddComment(" has no landing pad");
535 204473 : Asm->EmitULEB128(0);
536 : } else {
537 358516 : if (VerboseAsm)
538 762 : Asm->OutStreamer->AddComment(Twine(" jumps to ") +
539 1143 : S.LPad->LandingPadLabel->getName());
540 358516 : Asm->EmitLabelDifferenceAsULEB128(S.LPad->LandingPadLabel,
541 : EHFuncBeginSym);
542 : }
543 :
544 : // Offset of the first associated action record, relative to the start of
545 : // the action table. This value is biased by 1 (1 indicates the start of
546 : // the action table), and 0 indicates that there are no actions.
547 562989 : if (VerboseAsm) {
548 612 : if (S.Action == 0)
549 1176 : Asm->OutStreamer->AddComment(" On action: cleanup");
550 : else
551 220 : Asm->OutStreamer->AddComment(" On action: " +
552 440 : Twine((S.Action - 1) / 2 + 1));
553 : }
554 562989 : Asm->EmitULEB128(S.Action);
555 : }
556 : }
557 93560 : Asm->OutStreamer->EmitLabel(CstEndLabel);
558 :
559 : // Emit the Action Table.
560 : int Entry = 0;
561 40215 : for (SmallVectorImpl<ActionEntry>::const_iterator
562 86995 : I = Actions.begin(), E = Actions.end(); I != E; ++I) {
563 : const ActionEntry &Action = *I;
564 :
565 40215 : if (VerboseAsm) {
566 : // Emit comments that decode the action table.
567 900 : Asm->OutStreamer->AddComment(">> Action Record " + Twine(++Entry) + " <<");
568 : }
569 :
570 : // Type Filter
571 : //
572 : // Used by the runtime to match the type of the thrown exception to the
573 : // type of the catch clauses or the types in the exception specification.
574 40215 : if (VerboseAsm) {
575 225 : if (Action.ValueForTypeID > 0)
576 209 : Asm->OutStreamer->AddComment(" Catch TypeInfo " +
577 418 : Twine(Action.ValueForTypeID));
578 16 : else if (Action.ValueForTypeID < 0)
579 6 : Asm->OutStreamer->AddComment(" Filter TypeInfo " +
580 12 : Twine(Action.ValueForTypeID));
581 : else
582 30 : Asm->OutStreamer->AddComment(" Cleanup");
583 : }
584 40215 : Asm->EmitSLEB128(Action.ValueForTypeID);
585 :
586 : // Action Record
587 : //
588 : // Self-relative signed displacement in bytes of the next action record,
589 : // or 0 if there is no next action record.
590 40215 : if (VerboseAsm) {
591 225 : if (Action.NextAction == 0) {
592 588 : Asm->OutStreamer->AddComment(" No further actions");
593 : } else {
594 29 : unsigned NextAction = Entry + (Action.NextAction + 1) / 2;
595 58 : Asm->OutStreamer->AddComment(" Continue to action "+Twine(NextAction));
596 : }
597 : }
598 40215 : Asm->EmitSLEB128(Action.NextAction);
599 : }
600 :
601 46780 : if (HaveTTData) {
602 26453 : Asm->EmitAlignment(2);
603 26453 : emitTypeInfos(TTypeEncoding, TTBaseLabel);
604 : }
605 :
606 46780 : Asm->EmitAlignment(2);
607 46780 : }
608 :
609 26423 : void EHStreamer::emitTypeInfos(unsigned TTypeEncoding, MCSymbol *TTBaseLabel) {
610 26423 : const MachineFunction *MF = Asm->MF;
611 : const std::vector<const GlobalValue *> &TypeInfos = MF->getTypeInfos();
612 : const std::vector<unsigned> &FilterIds = MF->getFilterIds();
613 :
614 26423 : bool VerboseAsm = Asm->OutStreamer->isVerboseAsm();
615 :
616 : int Entry = 0;
617 : // Emit the Catch TypeInfos.
618 26423 : if (VerboseAsm && !TypeInfos.empty()) {
619 489 : Asm->OutStreamer->AddComment(">> Catch TypeInfos <<");
620 326 : Asm->OutStreamer->AddBlankLine();
621 326 : Entry = TypeInfos.size();
622 : }
623 :
624 : for (const GlobalValue *GV : make_range(TypeInfos.rbegin(),
625 63114 : TypeInfos.rend())) {
626 36691 : if (VerboseAsm)
627 366 : Asm->OutStreamer->AddComment("TypeInfo " + Twine(Entry--));
628 36691 : Asm->EmitTTypeReference(GV, TTypeEncoding);
629 : }
630 :
631 52846 : Asm->OutStreamer->EmitLabel(TTBaseLabel);
632 :
633 : // Emit the Exception Specifications.
634 26423 : if (VerboseAsm && !FilterIds.empty()) {
635 18 : Asm->OutStreamer->AddComment(">> Filter TypeInfos <<");
636 12 : Asm->OutStreamer->AddBlankLine();
637 : Entry = 0;
638 : }
639 : for (std::vector<unsigned>::const_iterator
640 27366 : I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) {
641 943 : unsigned TypeID = *I;
642 943 : if (VerboseAsm) {
643 7 : --Entry;
644 7 : if (isFilterEHSelector(TypeID))
645 0 : Asm->OutStreamer->AddComment("FilterInfo " + Twine(Entry));
646 : }
647 :
648 943 : Asm->EmitULEB128(TypeID);
649 : }
650 26423 : }
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