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->is_EHSymbolPrivate())
61 O << TAI->getPrivateGlobalPrefix();
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 const Function *TheFunc = EHFrameInfo.function;
152 Asm->SwitchToTextSection(TAI->getDwarfEHFrameSection());
154 // Externally visible entry into the functions eh frame info. If the
155 // corresponding function is static, this should not be externally visible.
156 if (!TheFunc->hasLocalLinkage())
157 if (const char *GlobalEHDirective = TAI->getGlobalEHDirective())
158 O << GlobalEHDirective << EHFrameInfo.FnName << "\n";
160 // If corresponding function is weak definition, this should be too.
161 if (TheFunc->isWeakForLinker() && TAI->getWeakDefDirective())
162 O << TAI->getWeakDefDirective() << EHFrameInfo.FnName << "\n";
164 // If there are no calls then you can't unwind. This may mean we can omit the
165 // EH Frame, but some environments do not handle weak absolute symbols. If
166 // UnwindTablesMandatory is set we cannot do this optimization; the unwind
167 // info is to be available for non-EH uses.
168 if (!EHFrameInfo.hasCalls && !UnwindTablesMandatory &&
169 (!TheFunc->isWeakForLinker() ||
170 !TAI->getWeakDefDirective() ||
171 TAI->getSupportsWeakOmittedEHFrame())) {
172 O << EHFrameInfo.FnName << " = 0\n";
173 // This name has no connection to the function, so it might get
174 // dead-stripped when the function is not, erroneously. Prohibit
175 // dead-stripping unconditionally.
176 if (const char *UsedDirective = TAI->getUsedDirective())
177 O << UsedDirective << EHFrameInfo.FnName << "\n\n";
179 O << EHFrameInfo.FnName << ":\n";
182 EmitDifference("eh_frame_end", EHFrameInfo.Number,
183 "eh_frame_begin", EHFrameInfo.Number, true);
184 Asm->EOL("Length of Frame Information Entry");
186 EmitLabel("eh_frame_begin", EHFrameInfo.Number);
188 EmitSectionOffset("eh_frame_begin", "eh_frame_common",
189 EHFrameInfo.Number, EHFrameInfo.PersonalityIndex,
192 Asm->EOL("FDE CIE offset");
194 EmitReference("eh_func_begin", EHFrameInfo.Number, true, true);
195 Asm->EOL("FDE initial location");
196 EmitDifference("eh_func_end", EHFrameInfo.Number,
197 "eh_func_begin", EHFrameInfo.Number, true);
198 Asm->EOL("FDE address range");
200 // If there is a personality and landing pads then point to the language
201 // specific data area in the exception table.
202 if (EHFrameInfo.PersonalityIndex) {
203 Asm->EmitULEB128Bytes(4);
204 Asm->EOL("Augmentation size");
206 if (EHFrameInfo.hasLandingPads)
207 EmitReference("exception", EHFrameInfo.Number, true, true);
209 Asm->EmitInt32((int)0);
210 Asm->EOL("Language Specific Data Area");
212 Asm->EmitULEB128Bytes(0);
213 Asm->EOL("Augmentation size");
216 // Indicate locations of function specific callee saved registers in frame.
217 EmitFrameMoves("eh_func_begin", EHFrameInfo.Number, EHFrameInfo.Moves,
220 // On Darwin the linker honors the alignment of eh_frame, which means it
221 // must be 8-byte on 64-bit targets to match what gcc does. Otherwise you
222 // get holes which confuse readers of eh_frame.
223 Asm->EmitAlignment(TD->getPointerSize() == sizeof(int32_t) ? 2 : 3,
225 EmitLabel("eh_frame_end", EHFrameInfo.Number);
227 // If the function is marked used, this table should be also. We cannot
228 // make the mark unconditional in this case, since retaining the table also
229 // retains the function in this case, and there is code around that depends
230 // on unused functions (calling undefined externals) being dead-stripped to
231 // link correctly. Yes, there really is.
232 if (MMI->isUsedFunction(EHFrameInfo.function))
233 if (const char *UsedDirective = TAI->getUsedDirective())
234 O << UsedDirective << EHFrameInfo.FnName << "\n\n";
238 /// EmitExceptionTable - Emit landing pads and actions.
240 /// The general organization of the table is complex, but the basic concepts are
241 /// easy. First there is a header which describes the location and organization
242 /// of the three components that follow.
244 /// 1. The landing pad site information describes the range of code covered by
245 /// the try. In our case it's an accumulation of the ranges covered by the
246 /// invokes in the try. There is also a reference to the landing pad that
247 /// handles the exception once processed. Finally an index into the actions
249 /// 2. The action table, in our case, is composed of pairs of type ids and next
250 /// action offset. Starting with the action index from the landing pad
251 /// site, each type Id is checked for a match to the current exception. If
252 /// it matches then the exception and type id are passed on to the landing
253 /// pad. Otherwise the next action is looked up. This chain is terminated
254 /// with a next action of zero. If no type id is found the the frame is
255 /// unwound and handling continues.
256 /// 3. Type id table contains references to all the C++ typeinfo for all
257 /// catches in the function. This tables is reversed indexed base 1.
259 /// SharedTypeIds - How many leading type ids two landing pads have in common.
260 unsigned DwarfException::SharedTypeIds(const LandingPadInfo *L,
261 const LandingPadInfo *R) {
262 const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
263 unsigned LSize = LIds.size(), RSize = RIds.size();
264 unsigned MinSize = LSize < RSize ? LSize : RSize;
267 for (; Count != MinSize; ++Count)
268 if (LIds[Count] != RIds[Count])
274 /// PadLT - Order landing pads lexicographically by type id.
275 bool DwarfException::PadLT(const LandingPadInfo *L, const LandingPadInfo *R) {
276 const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
277 unsigned LSize = LIds.size(), RSize = RIds.size();
278 unsigned MinSize = LSize < RSize ? LSize : RSize;
280 for (unsigned i = 0; i != MinSize; ++i)
281 if (LIds[i] != RIds[i])
282 return LIds[i] < RIds[i];
284 return LSize < RSize;
287 // ComputeActionsTable - Compute the actions table and gather the first action
288 // index for each landing pad site.
290 DwarfException::ComputeActionsTable(const SmallVectorImpl<const LandingPadInfo*>
292 SmallVectorImpl<ActionEntry> &Actions,
293 SmallVectorImpl<unsigned> &FirstActions) {
294 const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
296 // Negative type IDs index into FilterIds. Positive type IDs index into
297 // TypeInfos. The value written for a positive type ID is just the type ID
298 // itself. For a negative type ID, however, the value written is the
299 // (negative) byte offset of the corresponding FilterIds entry. The byte
300 // offset is usually equal to the type ID (because the FilterIds entries are
301 // written using a variable width encoding, which outputs one byte per entry
302 // as long as the value written is not too large) but can differ. This kind
303 // of complication does not occur for positive type IDs because type infos are
304 // output using a fixed width encoding. FilterOffsets[i] holds the byte
305 // offset corresponding to FilterIds[i].
306 SmallVector<int, 16> FilterOffsets;
307 FilterOffsets.reserve(FilterIds.size());
309 for(std::vector<unsigned>::const_iterator
310 I = FilterIds.begin(), E = FilterIds.end(); I != E; ++I) {
311 FilterOffsets.push_back(Offset);
312 Offset -= TargetAsmInfo::getULEB128Size(*I);
315 FirstActions.reserve(LandingPads.size());
318 unsigned SizeActions = 0;
319 const LandingPadInfo *PrevLPI = 0;
320 for (SmallVector<const LandingPadInfo *, 64>::const_iterator
321 I = LandingPads.begin(), E = LandingPads.end(); I != E; ++I) {
322 const LandingPadInfo *LPI = *I;
323 const std::vector<int> &TypeIds = LPI->TypeIds;
324 const unsigned NumShared = PrevLPI ? SharedTypeIds(LPI, PrevLPI) : 0;
325 unsigned SizeSiteActions = 0;
327 if (NumShared < TypeIds.size()) {
328 unsigned SizeAction = 0;
329 ActionEntry *PrevAction = 0;
332 const unsigned SizePrevIds = PrevLPI->TypeIds.size();
333 assert(Actions.size());
334 PrevAction = &Actions.back();
335 SizeAction = TargetAsmInfo::getSLEB128Size(PrevAction->NextAction) +
336 TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
338 for (unsigned j = NumShared; j != SizePrevIds; ++j) {
340 TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
341 SizeAction += -PrevAction->NextAction;
342 PrevAction = PrevAction->Previous;
346 // Compute the actions.
347 for (unsigned J = NumShared, M = TypeIds.size(); J != M; ++J) {
348 int TypeID = TypeIds[J];
349 assert(-1 - TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
350 int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID;
351 unsigned SizeTypeID = TargetAsmInfo::getSLEB128Size(ValueForTypeID);
353 int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0;
354 SizeAction = SizeTypeID + TargetAsmInfo::getSLEB128Size(NextAction);
355 SizeSiteActions += SizeAction;
357 ActionEntry Action = {ValueForTypeID, NextAction, PrevAction};
358 Actions.push_back(Action);
359 PrevAction = &Actions.back();
362 // Record the first action of the landing pad site.
363 FirstAction = SizeActions + SizeSiteActions - SizeAction + 1;
364 } // else identical - re-use previous FirstAction
366 FirstActions.push_back(FirstAction);
368 // Compute this sites contribution to size.
369 SizeActions += SizeSiteActions;
377 void DwarfException::EmitExceptionTable() {
378 const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
379 const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
380 const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
381 if (PadInfos.empty()) return;
383 // Sort the landing pads in order of their type ids. This is used to fold
384 // duplicate actions.
385 SmallVector<const LandingPadInfo *, 64> LandingPads;
386 LandingPads.reserve(PadInfos.size());
387 for (unsigned i = 0, N = PadInfos.size(); i != N; ++i)
388 LandingPads.push_back(&PadInfos[i]);
389 std::sort(LandingPads.begin(), LandingPads.end(), PadLT);
391 // Compute the actions table and gather the first action index for each
393 SmallVector<ActionEntry, 32> Actions;
394 SmallVector<unsigned, 64> FirstActions;
395 unsigned SizeActions = ComputeActionsTable(LandingPads, Actions, FirstActions);
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;
406 // Invokes and nounwind calls have entries in PadMap (due to being bracketed
407 // by try-range labels when lowered). Ordinary calls do not, so appropriate
408 // try-ranges for them need be deduced.
409 for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
410 const LandingPadInfo *LandingPad = LandingPads[i];
411 for (unsigned j = 0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
412 unsigned BeginLabel = LandingPad->BeginLabels[j];
413 assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
414 PadRange P = { i, j };
415 PadMap[BeginLabel] = P;
419 // The end label of the previous invoke or nounwind try-range.
420 unsigned LastLabel = 0;
422 // Whether there is a potentially throwing instruction (currently this means
423 // an ordinary call) between the end of the previous try-range and now.
424 bool SawPotentiallyThrowing = false;
426 // Whether the last callsite entry was for an invoke.
427 bool PreviousIsInvoke = false;
429 // Visit all instructions in order of address.
430 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
432 for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end();
434 if (!MI->isLabel()) {
435 SawPotentiallyThrowing |= MI->getDesc().isCall();
439 unsigned BeginLabel = MI->getOperand(0).getImm();
440 assert(BeginLabel && "Invalid label!");
442 // End of the previous try-range?
443 if (BeginLabel == LastLabel)
444 SawPotentiallyThrowing = false;
446 // Beginning of a new try-range?
447 RangeMapType::iterator L = PadMap.find(BeginLabel);
448 if (L == PadMap.end())
449 // Nope, it was just some random label.
452 PadRange P = L->second;
453 const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
455 assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
456 "Inconsistent landing pad map!");
458 // If some instruction between the previous try-range and this one may
459 // throw, create a call-site entry with no landing pad for the region
460 // between the try-ranges.
461 if (SawPotentiallyThrowing) {
462 CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
463 CallSites.push_back(Site);
464 PreviousIsInvoke = false;
467 LastLabel = LandingPad->EndLabels[P.RangeIndex];
468 assert(BeginLabel && LastLabel && "Invalid landing pad!");
470 if (LandingPad->LandingPadLabel) {
471 // This try-range is for an invoke.
472 CallSiteEntry Site = {BeginLabel, LastLabel,
473 LandingPad->LandingPadLabel,
474 FirstActions[P.PadIndex]};
476 // Try to merge with the previous call-site.
477 if (PreviousIsInvoke) {
478 CallSiteEntry &Prev = CallSites.back();
479 if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
480 // Extend the range of the previous entry.
481 Prev.EndLabel = Site.EndLabel;
486 // Otherwise, create a new call-site.
487 CallSites.push_back(Site);
488 PreviousIsInvoke = true;
491 PreviousIsInvoke = false;
496 // If some instruction between the previous try-range and the end of the
497 // function may throw, create a call-site entry with no landing pad for the
498 // region following the try-range.
499 if (SawPotentiallyThrowing) {
500 CallSiteEntry Site = {LastLabel, 0, 0, 0};
501 CallSites.push_back(Site);
507 const unsigned SiteStartSize = sizeof(int32_t); // DW_EH_PE_udata4
508 const unsigned SiteLengthSize = sizeof(int32_t); // DW_EH_PE_udata4
509 const unsigned LandingPadSize = sizeof(int32_t); // DW_EH_PE_udata4
510 unsigned SizeSites = CallSites.size() * (SiteStartSize +
513 for (unsigned i = 0, e = CallSites.size(); i < e; ++i)
514 SizeSites += TargetAsmInfo::getULEB128Size(CallSites[i].Action);
517 const unsigned TypeInfoSize = TD->getPointerSize(); // DW_EH_PE_absptr
518 unsigned SizeTypes = TypeInfos.size() * TypeInfoSize;
520 unsigned TypeOffset = sizeof(int8_t) + // Call site format
521 TargetAsmInfo::getULEB128Size(SizeSites) + // Call-site table length
522 SizeSites + SizeActions + SizeTypes;
524 unsigned TotalSize = sizeof(int8_t) + // LPStart format
525 sizeof(int8_t) + // TType format
526 TargetAsmInfo::getULEB128Size(TypeOffset) + // TType base offset
529 unsigned SizeAlign = (4 - TotalSize) & 3;
531 // Begin the exception table.
532 Asm->SwitchToDataSection(TAI->getDwarfExceptionSection());
533 Asm->EmitAlignment(2, 0, 0, false);
534 O << "GCC_except_table" << SubprogramCount << ":\n";
536 for (unsigned i = 0; i != SizeAlign; ++i) {
541 EmitLabel("exception", SubprogramCount);
544 Asm->EmitInt8(dwarf::DW_EH_PE_omit);
545 Asm->EOL("LPStart format (DW_EH_PE_omit)");
547 if (!TypeInfos.empty() || !FilterIds.empty()) {
548 Asm->EmitInt8(TAI->PreferredEHDataFormat(DwarfEncoding::Data, true));
549 // FIXME: The comment here should correspond with what PreferredEHDataFormat
551 Asm->EOL("TType format (DW_EH_PE_xxxxx)");
552 Asm->EmitULEB128Bytes(TypeOffset);
553 Asm->EOL("TType base offset");
555 Asm->EmitInt8(dwarf::DW_EH_PE_omit);
556 Asm->EOL("TType format (DW_EH_PE_omit)");
559 Asm->EmitInt8(dwarf::DW_EH_PE_udata4);
560 Asm->EOL("Call site format (DW_EH_PE_udata4)");
561 Asm->EmitULEB128Bytes(SizeSites);
562 Asm->EOL("Call-site table length");
564 // Emit the landing pad site information.
565 for (unsigned i = 0, e = CallSites.size(); i < e; ++i) {
566 const CallSiteEntry &S = CallSites[i];
567 const char *BeginTag;
568 unsigned BeginNumber;
571 BeginTag = "eh_func_begin";
572 BeginNumber = SubprogramCount;
575 BeginNumber = S.BeginLabel;
578 EmitSectionOffset(BeginTag, "eh_func_begin", BeginNumber, SubprogramCount,
580 Asm->EOL("Region start");
583 EmitDifference("eh_func_end", SubprogramCount, BeginTag, BeginNumber,
586 EmitDifference("label", S.EndLabel, BeginTag, BeginNumber, true);
588 Asm->EOL("Region length");
593 EmitSectionOffset("label", "eh_func_begin", S.PadLabel, SubprogramCount,
596 Asm->EOL("Landing pad");
598 Asm->EmitULEB128Bytes(S.Action);
603 for (unsigned I = 0, N = Actions.size(); I != N; ++I) {
604 ActionEntry &Action = Actions[I];
606 Asm->EmitSLEB128Bytes(Action.ValueForTypeID);
607 Asm->EOL("TypeInfo index");
608 Asm->EmitSLEB128Bytes(Action.NextAction);
609 Asm->EOL("Next action");
612 // Emit the type ids.
613 for (unsigned M = TypeInfos.size(); M; --M) {
614 GlobalVariable *GV = TypeInfos[M - 1];
619 O << Asm->getGlobalLinkName(GV, GLN);
624 Asm->EOL("TypeInfo");
627 // Emit the filter typeids.
628 for (unsigned j = 0, M = FilterIds.size(); j < M; ++j) {
629 unsigned TypeID = FilterIds[j];
630 Asm->EmitULEB128Bytes(TypeID);
631 Asm->EOL("Filter TypeInfo index");
634 Asm->EmitAlignment(2, 0, 0, false);
637 /// EndModule - Emit all exception information that should come after the
639 void DwarfException::EndModule() {
640 if (TimePassesIsEnabled)
641 ExceptionTimer->startTimer();
643 if (shouldEmitMovesModule || shouldEmitTableModule) {
644 const std::vector<Function *> Personalities = MMI->getPersonalities();
645 for (unsigned i = 0; i < Personalities.size(); ++i)
646 EmitCommonEHFrame(Personalities[i], i);
648 for (std::vector<FunctionEHFrameInfo>::iterator I = EHFrames.begin(),
649 E = EHFrames.end(); I != E; ++I)
653 if (TimePassesIsEnabled)
654 ExceptionTimer->stopTimer();
657 /// BeginFunction - Gather pre-function exception information. Assumes being
658 /// emitted immediately after the function entry point.
659 void DwarfException::BeginFunction(MachineFunction *MF) {
660 if (TimePassesIsEnabled)
661 ExceptionTimer->startTimer();
664 shouldEmitTable = shouldEmitMoves = false;
666 if (MMI && TAI->doesSupportExceptionHandling()) {
667 // Map all labels and get rid of any dead landing pads.
668 MMI->TidyLandingPads();
670 // If any landing pads survive, we need an EH table.
671 if (MMI->getLandingPads().size())
672 shouldEmitTable = true;
674 // See if we need frame move info.
675 if (!MF->getFunction()->doesNotThrow() || UnwindTablesMandatory)
676 shouldEmitMoves = true;
678 if (shouldEmitMoves || shouldEmitTable)
679 // Assumes in correct section after the entry point.
680 EmitLabel("eh_func_begin", ++SubprogramCount);
683 shouldEmitTableModule |= shouldEmitTable;
684 shouldEmitMovesModule |= shouldEmitMoves;
686 if (TimePassesIsEnabled)
687 ExceptionTimer->stopTimer();
690 /// EndFunction - Gather and emit post-function exception information.
692 void DwarfException::EndFunction() {
693 if (TimePassesIsEnabled)
694 ExceptionTimer->startTimer();
696 if (shouldEmitMoves || shouldEmitTable) {
697 EmitLabel("eh_func_end", SubprogramCount);
698 EmitExceptionTable();
700 // Save EH frame information
702 FunctionEHFrameInfo(getAsm()->getCurrentFunctionEHName(MF),
704 MMI->getPersonalityIndex(),
705 MF->getFrameInfo()->hasCalls(),
706 !MMI->getLandingPads().empty(),
707 MMI->getFrameMoves(),
711 if (TimePassesIsEnabled)
712 ExceptionTimer->stopTimer();