1 //===-- CodeGen/AsmPrinter/DwarfException.cpp - Dwarf Exception Impl ------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains support for writing dwarf exception info into asm files.
12 //===----------------------------------------------------------------------===//
14 #include "DwarfException.h"
15 #include "llvm/Module.h"
16 #include "llvm/CodeGen/MachineModuleInfo.h"
17 #include "llvm/CodeGen/MachineFrameInfo.h"
18 #include "llvm/CodeGen/MachineLocation.h"
19 #include "llvm/Support/Dwarf.h"
20 #include "llvm/Support/Timer.h"
21 #include "llvm/Support/raw_ostream.h"
22 #include "llvm/Target/TargetAsmInfo.h"
23 #include "llvm/Target/TargetRegisterInfo.h"
24 #include "llvm/Target/TargetData.h"
25 #include "llvm/Target/TargetFrameInfo.h"
26 #include "llvm/Target/TargetOptions.h"
27 #include "llvm/ADT/StringExtras.h"
30 static TimerGroup &getDwarfTimerGroup() {
31 static TimerGroup DwarfTimerGroup("Dwarf Exception");
32 return DwarfTimerGroup;
35 DwarfException::DwarfException(raw_ostream &OS, AsmPrinter *A,
36 const TargetAsmInfo *T)
37 : Dwarf(OS, A, T, "eh"), shouldEmitTable(false), shouldEmitMoves(false),
38 shouldEmitTableModule(false), shouldEmitMovesModule(false),
40 if (TimePassesIsEnabled)
41 ExceptionTimer = new Timer("Dwarf Exception Writer",
42 getDwarfTimerGroup());
45 DwarfException::~DwarfException() {
46 delete ExceptionTimer;
49 void DwarfException::EmitCommonEHFrame(const Function *Personality,
51 // Size and sign of stack growth.
53 Asm->TM.getFrameInfo()->getStackGrowthDirection() ==
54 TargetFrameInfo::StackGrowsUp ?
55 TD->getPointerSize() : -TD->getPointerSize();
57 // Begin eh frame section.
58 Asm->SwitchToTextSection(TAI->getDwarfEHFrameSection());
60 if (!TAI->doesRequireNonLocalEHFrameLabel())
61 O << TAI->getEHGlobalPrefix();
63 O << "EH_frame" << Index << ":\n";
64 EmitLabel("section_eh_frame", Index);
66 // Define base labels.
67 EmitLabel("eh_frame_common", Index);
69 // Define the eh frame length.
70 EmitDifference("eh_frame_common_end", Index,
71 "eh_frame_common_begin", Index, true);
72 Asm->EOL("Length of Common Information Entry");
75 EmitLabel("eh_frame_common_begin", Index);
76 Asm->EmitInt32((int)0);
77 Asm->EOL("CIE Identifier Tag");
78 Asm->EmitInt8(dwarf::DW_CIE_VERSION);
79 Asm->EOL("CIE Version");
81 // The personality presence indicates that language specific information will
82 // show up in the eh frame.
83 Asm->EmitString(Personality ? "zPLR" : "zR");
84 Asm->EOL("CIE Augmentation");
87 Asm->EmitULEB128Bytes(1);
88 Asm->EOL("CIE Code Alignment Factor");
89 Asm->EmitSLEB128Bytes(stackGrowth);
90 Asm->EOL("CIE Data Alignment Factor");
91 Asm->EmitInt8(RI->getDwarfRegNum(RI->getRARegister(), true));
92 Asm->EOL("CIE Return Address Column");
94 // If there is a personality, we need to indicate the functions location.
96 Asm->EmitULEB128Bytes(7);
97 Asm->EOL("Augmentation Size");
99 if (TAI->getNeedsIndirectEncoding()) {
100 Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4 |
101 dwarf::DW_EH_PE_indirect);
102 Asm->EOL("Personality (pcrel sdata4 indirect)");
104 Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
105 Asm->EOL("Personality (pcrel sdata4)");
108 PrintRelDirective(true);
109 O << TAI->getPersonalityPrefix();
110 Asm->EmitExternalGlobal((const GlobalVariable *)(Personality));
111 O << TAI->getPersonalitySuffix();
112 if (strcmp(TAI->getPersonalitySuffix(), "+4@GOTPCREL"))
113 O << "-" << TAI->getPCSymbol();
114 Asm->EOL("Personality");
116 Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
117 Asm->EOL("LSDA Encoding (pcrel sdata4)");
119 Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
120 Asm->EOL("FDE Encoding (pcrel sdata4)");
122 Asm->EmitULEB128Bytes(1);
123 Asm->EOL("Augmentation Size");
125 Asm->EmitInt8(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
126 Asm->EOL("FDE Encoding (pcrel sdata4)");
129 // Indicate locations of general callee saved registers in frame.
130 std::vector<MachineMove> Moves;
131 RI->getInitialFrameState(Moves);
132 EmitFrameMoves(NULL, 0, Moves, true);
134 // On Darwin the linker honors the alignment of eh_frame, which means it must
135 // be 8-byte on 64-bit targets to match what gcc does. Otherwise you get
136 // holes which confuse readers of eh_frame.
137 Asm->EmitAlignment(TD->getPointerSize() == sizeof(int32_t) ? 2 : 3,
139 EmitLabel("eh_frame_common_end", Index);
144 /// EmitEHFrame - Emit function exception frame information.
146 void DwarfException::EmitEHFrame(const FunctionEHFrameInfo &EHFrameInfo) {
147 assert(!EHFrameInfo.function->hasAvailableExternallyLinkage() &&
148 "Should not emit 'available externally' functions at all");
150 Function::LinkageTypes linkage = EHFrameInfo.function->getLinkage();
151 Asm->SwitchToTextSection(TAI->getDwarfEHFrameSection());
153 // Externally visible entry into the functions eh frame info. If the
154 // corresponding function is static, this should not be externally visible.
155 if (linkage != Function::InternalLinkage &&
156 linkage != Function::PrivateLinkage) {
157 if (const char *GlobalEHDirective = TAI->getGlobalEHDirective())
158 O << GlobalEHDirective << EHFrameInfo.FnName << "\n";
161 // If corresponding function is weak definition, this should be too.
162 if ((linkage == Function::WeakAnyLinkage ||
163 linkage == Function::WeakODRLinkage ||
164 linkage == Function::LinkOnceAnyLinkage ||
165 linkage == Function::LinkOnceODRLinkage) &&
166 TAI->getWeakDefDirective())
167 O << TAI->getWeakDefDirective() << EHFrameInfo.FnName << "\n";
169 // If there are no calls then you can't unwind. This may mean we can omit the
170 // EH Frame, but some environments do not handle weak absolute symbols. If
171 // UnwindTablesMandatory is set we cannot do this optimization; the unwind
172 // info is to be available for non-EH uses.
173 if (!EHFrameInfo.hasCalls &&
174 !UnwindTablesMandatory &&
175 ((linkage != Function::WeakAnyLinkage &&
176 linkage != Function::WeakODRLinkage &&
177 linkage != Function::LinkOnceAnyLinkage &&
178 linkage != Function::LinkOnceODRLinkage) ||
179 !TAI->getWeakDefDirective() ||
180 TAI->getSupportsWeakOmittedEHFrame())) {
181 O << EHFrameInfo.FnName << " = 0\n";
182 // This name has no connection to the function, so it might get
183 // dead-stripped when the function is not, erroneously. Prohibit
184 // dead-stripping unconditionally.
185 if (const char *UsedDirective = TAI->getUsedDirective())
186 O << UsedDirective << EHFrameInfo.FnName << "\n\n";
188 O << EHFrameInfo.FnName << ":\n";
191 EmitDifference("eh_frame_end", EHFrameInfo.Number,
192 "eh_frame_begin", EHFrameInfo.Number, true);
193 Asm->EOL("Length of Frame Information Entry");
195 EmitLabel("eh_frame_begin", EHFrameInfo.Number);
197 if (TAI->doesRequireNonLocalEHFrameLabel()) {
198 PrintRelDirective(true, true);
199 PrintLabelName("eh_frame_begin", EHFrameInfo.Number);
201 if (!TAI->isAbsoluteEHSectionOffsets())
202 O << "-EH_frame" << EHFrameInfo.PersonalityIndex;
204 EmitSectionOffset("eh_frame_begin", "eh_frame_common",
205 EHFrameInfo.Number, EHFrameInfo.PersonalityIndex,
209 Asm->EOL("FDE CIE offset");
211 EmitReference("eh_func_begin", EHFrameInfo.Number, true, true);
212 Asm->EOL("FDE initial location");
213 EmitDifference("eh_func_end", EHFrameInfo.Number,
214 "eh_func_begin", EHFrameInfo.Number, true);
215 Asm->EOL("FDE address range");
217 // If there is a personality and landing pads then point to the language
218 // specific data area in the exception table.
219 if (EHFrameInfo.PersonalityIndex) {
220 Asm->EmitULEB128Bytes(4);
221 Asm->EOL("Augmentation size");
223 if (EHFrameInfo.hasLandingPads)
224 EmitReference("exception", EHFrameInfo.Number, true, true);
226 Asm->EmitInt32((int)0);
227 Asm->EOL("Language Specific Data Area");
229 Asm->EmitULEB128Bytes(0);
230 Asm->EOL("Augmentation size");
233 // Indicate locations of function specific callee saved registers in frame.
234 EmitFrameMoves("eh_func_begin", EHFrameInfo.Number, EHFrameInfo.Moves,
237 // On Darwin the linker honors the alignment of eh_frame, which means it
238 // must be 8-byte on 64-bit targets to match what gcc does. Otherwise you
239 // get holes which confuse readers of eh_frame.
240 Asm->EmitAlignment(TD->getPointerSize() == sizeof(int32_t) ? 2 : 3,
242 EmitLabel("eh_frame_end", EHFrameInfo.Number);
244 // If the function is marked used, this table should be also. We cannot
245 // make the mark unconditional in this case, since retaining the table also
246 // retains the function in this case, and there is code around that depends
247 // on unused functions (calling undefined externals) being dead-stripped to
248 // link correctly. Yes, there really is.
249 if (MMI->getUsedFunctions().count(EHFrameInfo.function))
250 if (const char *UsedDirective = TAI->getUsedDirective())
251 O << UsedDirective << EHFrameInfo.FnName << "\n\n";
255 /// EmitExceptionTable - Emit landing pads and actions.
257 /// The general organization of the table is complex, but the basic concepts are
258 /// easy. First there is a header which describes the location and organization
259 /// of the three components that follow.
261 /// 1. The landing pad site information describes the range of code covered by
262 /// the try. In our case it's an accumulation of the ranges covered by the
263 /// invokes in the try. There is also a reference to the landing pad that
264 /// handles the exception once processed. Finally an index into the actions
266 /// 2. The action table, in our case, is composed of pairs of type ids and next
267 /// action offset. Starting with the action index from the landing pad
268 /// site, each type Id is checked for a match to the current exception. If
269 /// it matches then the exception and type id are passed on to the landing
270 /// pad. Otherwise the next action is looked up. This chain is terminated
271 /// with a next action of zero. If no type id is found the the frame is
272 /// unwound and handling continues.
273 /// 3. Type id table contains references to all the C++ typeinfo for all
274 /// catches in the function. This tables is reversed indexed base 1.
276 /// SharedTypeIds - How many leading type ids two landing pads have in common.
277 unsigned DwarfException::SharedTypeIds(const LandingPadInfo *L,
278 const LandingPadInfo *R) {
279 const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
280 unsigned LSize = LIds.size(), RSize = RIds.size();
281 unsigned MinSize = LSize < RSize ? LSize : RSize;
284 for (; Count != MinSize; ++Count)
285 if (LIds[Count] != RIds[Count])
291 /// PadLT - Order landing pads lexicographically by type id.
292 bool DwarfException::PadLT(const LandingPadInfo *L, const LandingPadInfo *R) {
293 const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
294 unsigned LSize = LIds.size(), RSize = RIds.size();
295 unsigned MinSize = LSize < RSize ? LSize : RSize;
297 for (unsigned i = 0; i != MinSize; ++i)
298 if (LIds[i] != RIds[i])
299 return LIds[i] < RIds[i];
301 return LSize < RSize;
304 void DwarfException::EmitExceptionTable() {
305 const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
306 const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
307 const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
308 if (PadInfos.empty()) return;
310 // Sort the landing pads in order of their type ids. This is used to fold
311 // duplicate actions.
312 SmallVector<const LandingPadInfo *, 64> LandingPads;
313 LandingPads.reserve(PadInfos.size());
314 for (unsigned i = 0, N = PadInfos.size(); i != N; ++i)
315 LandingPads.push_back(&PadInfos[i]);
316 std::sort(LandingPads.begin(), LandingPads.end(), PadLT);
318 // Negative type ids index into FilterIds, positive type ids index into
319 // TypeInfos. The value written for a positive type id is just the type id
320 // itself. For a negative type id, however, the value written is the
321 // (negative) byte offset of the corresponding FilterIds entry. The byte
322 // offset is usually equal to the type id, because the FilterIds entries are
323 // written using a variable width encoding which outputs one byte per entry as
324 // long as the value written is not too large, but can differ. This kind of
325 // complication does not occur for positive type ids because type infos are
326 // output using a fixed width encoding. FilterOffsets[i] holds the byte
327 // offset corresponding to FilterIds[i].
328 SmallVector<int, 16> FilterOffsets;
329 FilterOffsets.reserve(FilterIds.size());
331 for(std::vector<unsigned>::const_iterator I = FilterIds.begin(),
332 E = FilterIds.end(); I != E; ++I) {
333 FilterOffsets.push_back(Offset);
334 Offset -= TargetAsmInfo::getULEB128Size(*I);
337 // Compute the actions table and gather the first action index for each
339 SmallVector<ActionEntry, 32> Actions;
340 SmallVector<unsigned, 64> FirstActions;
341 FirstActions.reserve(LandingPads.size());
344 unsigned SizeActions = 0;
345 for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
346 const LandingPadInfo *LP = LandingPads[i];
347 const std::vector<int> &TypeIds = LP->TypeIds;
348 const unsigned NumShared = i ? SharedTypeIds(LP, LandingPads[i-1]) : 0;
349 unsigned SizeSiteActions = 0;
351 if (NumShared < TypeIds.size()) {
352 unsigned SizeAction = 0;
353 ActionEntry *PrevAction = 0;
356 const unsigned SizePrevIds = LandingPads[i-1]->TypeIds.size();
357 assert(Actions.size());
358 PrevAction = &Actions.back();
359 SizeAction = TargetAsmInfo::getSLEB128Size(PrevAction->NextAction) +
360 TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
362 for (unsigned j = NumShared; j != SizePrevIds; ++j) {
364 TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
365 SizeAction += -PrevAction->NextAction;
366 PrevAction = PrevAction->Previous;
370 // Compute the actions.
371 for (unsigned I = NumShared, M = TypeIds.size(); I != M; ++I) {
372 int TypeID = TypeIds[I];
373 assert(-1-TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
374 int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID;
375 unsigned SizeTypeID = TargetAsmInfo::getSLEB128Size(ValueForTypeID);
377 int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0;
378 SizeAction = SizeTypeID + TargetAsmInfo::getSLEB128Size(NextAction);
379 SizeSiteActions += SizeAction;
381 ActionEntry Action = {ValueForTypeID, NextAction, PrevAction};
382 Actions.push_back(Action);
384 PrevAction = &Actions.back();
387 // Record the first action of the landing pad site.
388 FirstAction = SizeActions + SizeSiteActions - SizeAction + 1;
389 } // else identical - re-use previous FirstAction
391 FirstActions.push_back(FirstAction);
393 // Compute this sites contribution to size.
394 SizeActions += SizeSiteActions;
397 // Compute the call-site table. The entry for an invoke has a try-range
398 // containing the call, a non-zero landing pad and an appropriate action. The
399 // entry for an ordinary call has a try-range containing the call and zero for
400 // the landing pad and the action. Calls marked 'nounwind' have no entry and
401 // must not be contained in the try-range of any entry - they form gaps in the
402 // table. Entries must be ordered by try-range address.
403 SmallVector<CallSiteEntry, 64> CallSites;
407 // Invokes and nounwind calls have entries in PadMap (due to being bracketed
408 // by try-range labels when lowered). Ordinary calls do not, so appropriate
409 // try-ranges for them need be deduced.
410 for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
411 const LandingPadInfo *LandingPad = LandingPads[i];
412 for (unsigned j = 0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
413 unsigned BeginLabel = LandingPad->BeginLabels[j];
414 assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
415 PadRange P = { i, j };
416 PadMap[BeginLabel] = P;
420 // The end label of the previous invoke or nounwind try-range.
421 unsigned LastLabel = 0;
423 // Whether there is a potentially throwing instruction (currently this means
424 // an ordinary call) between the end of the previous try-range and now.
425 bool SawPotentiallyThrowing = false;
427 // Whether the last callsite entry was for an invoke.
428 bool PreviousIsInvoke = false;
430 // Visit all instructions in order of address.
431 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
433 for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end();
435 if (!MI->isLabel()) {
436 SawPotentiallyThrowing |= MI->getDesc().isCall();
440 unsigned BeginLabel = MI->getOperand(0).getImm();
441 assert(BeginLabel && "Invalid label!");
443 // End of the previous try-range?
444 if (BeginLabel == LastLabel)
445 SawPotentiallyThrowing = false;
447 // Beginning of a new try-range?
448 RangeMapType::iterator L = PadMap.find(BeginLabel);
449 if (L == PadMap.end())
450 // Nope, it was just some random label.
453 PadRange P = L->second;
454 const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
456 assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
457 "Inconsistent landing pad map!");
459 // If some instruction between the previous try-range and this one may
460 // throw, create a call-site entry with no landing pad for the region
461 // between the try-ranges.
462 if (SawPotentiallyThrowing) {
463 CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
464 CallSites.push_back(Site);
465 PreviousIsInvoke = false;
468 LastLabel = LandingPad->EndLabels[P.RangeIndex];
469 assert(BeginLabel && LastLabel && "Invalid landing pad!");
471 if (LandingPad->LandingPadLabel) {
472 // This try-range is for an invoke.
473 CallSiteEntry Site = {BeginLabel, LastLabel,
474 LandingPad->LandingPadLabel,
475 FirstActions[P.PadIndex]};
477 // Try to merge with the previous call-site.
478 if (PreviousIsInvoke) {
479 CallSiteEntry &Prev = CallSites.back();
480 if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
481 // Extend the range of the previous entry.
482 Prev.EndLabel = Site.EndLabel;
487 // Otherwise, create a new call-site.
488 CallSites.push_back(Site);
489 PreviousIsInvoke = true;
492 PreviousIsInvoke = false;
497 // If some instruction between the previous try-range and the end of the
498 // function may throw, create a call-site entry with no landing pad for the
499 // region following the try-range.
500 if (SawPotentiallyThrowing) {
501 CallSiteEntry Site = {LastLabel, 0, 0, 0};
502 CallSites.push_back(Site);
508 const unsigned SiteStartSize = sizeof(int32_t); // DW_EH_PE_udata4
509 const unsigned SiteLengthSize = sizeof(int32_t); // DW_EH_PE_udata4
510 const unsigned LandingPadSize = sizeof(int32_t); // DW_EH_PE_udata4
511 unsigned SizeSites = CallSites.size() * (SiteStartSize +
514 for (unsigned i = 0, e = CallSites.size(); i < e; ++i)
515 SizeSites += TargetAsmInfo::getULEB128Size(CallSites[i].Action);
518 const unsigned TypeInfoSize = TD->getPointerSize(); // DW_EH_PE_absptr
519 unsigned SizeTypes = TypeInfos.size() * TypeInfoSize;
521 unsigned TypeOffset = sizeof(int8_t) + // Call site format
522 TargetAsmInfo::getULEB128Size(SizeSites) + // Call-site table length
523 SizeSites + SizeActions + SizeTypes;
525 unsigned TotalSize = sizeof(int8_t) + // LPStart format
526 sizeof(int8_t) + // TType format
527 TargetAsmInfo::getULEB128Size(TypeOffset) + // TType base offset
530 unsigned SizeAlign = (4 - TotalSize) & 3;
532 // Begin the exception table.
533 Asm->SwitchToDataSection(TAI->getDwarfExceptionSection());
534 Asm->EmitAlignment(2, 0, 0, false);
535 O << "GCC_except_table" << SubprogramCount << ":\n";
537 for (unsigned i = 0; i != SizeAlign; ++i) {
542 EmitLabel("exception", SubprogramCount);
545 Asm->EmitInt8(dwarf::DW_EH_PE_omit);
546 Asm->EOL("LPStart format (DW_EH_PE_omit)");
547 Asm->EmitInt8(dwarf::DW_EH_PE_absptr);
548 Asm->EOL("TType format (DW_EH_PE_absptr)");
549 Asm->EmitULEB128Bytes(TypeOffset);
550 Asm->EOL("TType base offset");
551 Asm->EmitInt8(dwarf::DW_EH_PE_udata4);
552 Asm->EOL("Call site format (DW_EH_PE_udata4)");
553 Asm->EmitULEB128Bytes(SizeSites);
554 Asm->EOL("Call-site table length");
556 // Emit the landing pad site information.
557 for (unsigned i = 0; i < CallSites.size(); ++i) {
558 CallSiteEntry &S = CallSites[i];
559 const char *BeginTag;
560 unsigned BeginNumber;
563 BeginTag = "eh_func_begin";
564 BeginNumber = SubprogramCount;
567 BeginNumber = S.BeginLabel;
570 EmitSectionOffset(BeginTag, "eh_func_begin", BeginNumber, SubprogramCount,
572 Asm->EOL("Region start");
575 EmitDifference("eh_func_end", SubprogramCount, BeginTag, BeginNumber,
578 EmitDifference("label", S.EndLabel, BeginTag, BeginNumber, true);
580 Asm->EOL("Region length");
585 EmitSectionOffset("label", "eh_func_begin", S.PadLabel, SubprogramCount,
588 Asm->EOL("Landing pad");
590 Asm->EmitULEB128Bytes(S.Action);
595 for (unsigned I = 0, N = Actions.size(); I != N; ++I) {
596 ActionEntry &Action = Actions[I];
598 Asm->EmitSLEB128Bytes(Action.ValueForTypeID);
599 Asm->EOL("TypeInfo index");
600 Asm->EmitSLEB128Bytes(Action.NextAction);
601 Asm->EOL("Next action");
604 // Emit the type ids.
605 for (unsigned M = TypeInfos.size(); M; --M) {
606 GlobalVariable *GV = TypeInfos[M - 1];
611 O << Asm->getGlobalLinkName(GV, GLN);
616 Asm->EOL("TypeInfo");
619 // Emit the filter typeids.
620 for (unsigned j = 0, M = FilterIds.size(); j < M; ++j) {
621 unsigned TypeID = FilterIds[j];
622 Asm->EmitULEB128Bytes(TypeID);
623 Asm->EOL("Filter TypeInfo index");
626 Asm->EmitAlignment(2, 0, 0, false);
629 /// EndModule - Emit all exception information that should come after the
631 void DwarfException::EndModule() {
632 if (TimePassesIsEnabled)
633 ExceptionTimer->startTimer();
635 if (shouldEmitMovesModule || shouldEmitTableModule) {
636 const std::vector<Function *> Personalities = MMI->getPersonalities();
637 for (unsigned i = 0; i < Personalities.size(); ++i)
638 EmitCommonEHFrame(Personalities[i], i);
640 for (std::vector<FunctionEHFrameInfo>::iterator I = EHFrames.begin(),
641 E = EHFrames.end(); I != E; ++I)
645 if (TimePassesIsEnabled)
646 ExceptionTimer->stopTimer();
649 /// BeginFunction - Gather pre-function exception information. Assumes being
650 /// emitted immediately after the function entry point.
651 void DwarfException::BeginFunction(MachineFunction *MF) {
652 if (TimePassesIsEnabled)
653 ExceptionTimer->startTimer();
656 shouldEmitTable = shouldEmitMoves = false;
658 if (MMI && TAI->doesSupportExceptionHandling()) {
659 // Map all labels and get rid of any dead landing pads.
660 MMI->TidyLandingPads();
662 // If any landing pads survive, we need an EH table.
663 if (MMI->getLandingPads().size())
664 shouldEmitTable = true;
666 // See if we need frame move info.
667 if (!MF->getFunction()->doesNotThrow() || UnwindTablesMandatory)
668 shouldEmitMoves = true;
670 if (shouldEmitMoves || shouldEmitTable)
671 // Assumes in correct section after the entry point.
672 EmitLabel("eh_func_begin", ++SubprogramCount);
675 shouldEmitTableModule |= shouldEmitTable;
676 shouldEmitMovesModule |= shouldEmitMoves;
678 if (TimePassesIsEnabled)
679 ExceptionTimer->stopTimer();
682 /// EndFunction - Gather and emit post-function exception information.
684 void DwarfException::EndFunction() {
685 if (TimePassesIsEnabled)
686 ExceptionTimer->startTimer();
688 if (shouldEmitMoves || shouldEmitTable) {
689 EmitLabel("eh_func_end", SubprogramCount);
690 EmitExceptionTable();
692 // Save EH frame information
695 FunctionEHFrameInfo(getAsm()->getCurrentFunctionEHName(MF, Name),
697 MMI->getPersonalityIndex(),
698 MF->getFrameInfo()->hasCalls(),
699 !MMI->getLandingPads().empty(),
700 MMI->getFrameMoves(),
704 if (TimePassesIsEnabled)
705 ExceptionTimer->stopTimer();