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.
289 unsigned DwarfException::
290 ComputeActionsTable(const SmallVectorImpl<const LandingPadInfo*> &LandingPads,
291 SmallVectorImpl<ActionEntry> &Actions,
292 SmallVectorImpl<unsigned> &FirstActions) {
293 const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
295 // Negative type IDs index into FilterIds. Positive type IDs index into
296 // TypeInfos. The value written for a positive type ID is just the type ID
297 // itself. For a negative type ID, however, the value written is the
298 // (negative) byte offset of the corresponding FilterIds entry. The byte
299 // offset is usually equal to the type ID (because the FilterIds entries are
300 // written using a variable width encoding, which outputs one byte per entry
301 // as long as the value written is not too large) but can differ. This kind
302 // of complication does not occur for positive type IDs because type infos are
303 // output using a fixed width encoding. FilterOffsets[i] holds the byte
304 // offset corresponding to FilterIds[i].
305 SmallVector<int, 16> FilterOffsets;
306 FilterOffsets.reserve(FilterIds.size());
308 for(std::vector<unsigned>::const_iterator
309 I = FilterIds.begin(), E = FilterIds.end(); I != E; ++I) {
310 FilterOffsets.push_back(Offset);
311 Offset -= TargetAsmInfo::getULEB128Size(*I);
314 FirstActions.reserve(LandingPads.size());
317 unsigned SizeActions = 0;
318 const LandingPadInfo *PrevLPI = 0;
319 for (SmallVectorImpl<const LandingPadInfo *>::const_iterator
320 I = LandingPads.begin(), E = LandingPads.end(); I != E; ++I) {
321 const LandingPadInfo *LPI = *I;
322 const std::vector<int> &TypeIds = LPI->TypeIds;
323 const unsigned NumShared = PrevLPI ? SharedTypeIds(LPI, PrevLPI) : 0;
324 unsigned SizeSiteActions = 0;
326 if (NumShared < TypeIds.size()) {
327 unsigned SizeAction = 0;
328 ActionEntry *PrevAction = 0;
331 const unsigned SizePrevIds = PrevLPI->TypeIds.size();
332 assert(Actions.size());
333 PrevAction = &Actions.back();
334 SizeAction = TargetAsmInfo::getSLEB128Size(PrevAction->NextAction) +
335 TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
337 for (unsigned j = NumShared; j != SizePrevIds; ++j) {
339 TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
340 SizeAction += -PrevAction->NextAction;
341 PrevAction = PrevAction->Previous;
345 // Compute the actions.
346 for (unsigned J = NumShared, M = TypeIds.size(); J != M; ++J) {
347 int TypeID = TypeIds[J];
348 assert(-1 - TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
349 int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID;
350 unsigned SizeTypeID = TargetAsmInfo::getSLEB128Size(ValueForTypeID);
352 int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0;
353 SizeAction = SizeTypeID + TargetAsmInfo::getSLEB128Size(NextAction);
354 SizeSiteActions += SizeAction;
356 ActionEntry Action = {ValueForTypeID, NextAction, PrevAction};
357 Actions.push_back(Action);
358 PrevAction = &Actions.back();
361 // Record the first action of the landing pad site.
362 FirstAction = SizeActions + SizeSiteActions - SizeAction + 1;
363 } // else identical - re-use previous FirstAction
365 FirstActions.push_back(FirstAction);
367 // Compute this sites contribution to size.
368 SizeActions += SizeSiteActions;
376 /// ComputeCallSiteTable - Compute the call-site table. The entry for an invoke
377 /// has a try-range containing the call, a non-zero landing pad and an
378 /// appropriate action. The entry for an ordinary call has a try-range
379 /// containing the call and zero for the landing pad and the action. Calls
380 /// marked 'nounwind' have no entry and must not be contained in the try-range
381 /// of any entry - they form gaps in the table. Entries must be ordered by
382 /// try-range address.
383 void DwarfException::
384 ComputeCallSiteTable(SmallVectorImpl<CallSiteEntry> &CallSites,
385 const RangeMapType &PadMap,
386 const SmallVectorImpl<const LandingPadInfo *> &LandingPads,
387 const SmallVectorImpl<unsigned> &FirstActions) {
388 // The end label of the previous invoke or nounwind try-range.
389 unsigned LastLabel = 0;
391 // Whether there is a potentially throwing instruction (currently this means
392 // an ordinary call) between the end of the previous try-range and now.
393 bool SawPotentiallyThrowing = false;
395 // Whether the last CallSite entry was for an invoke.
396 bool PreviousIsInvoke = false;
398 // Visit all instructions in order of address.
399 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
401 for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end();
403 if (!MI->isLabel()) {
404 SawPotentiallyThrowing |= MI->getDesc().isCall();
408 unsigned BeginLabel = MI->getOperand(0).getImm();
409 assert(BeginLabel && "Invalid label!");
411 // End of the previous try-range?
412 if (BeginLabel == LastLabel)
413 SawPotentiallyThrowing = false;
415 // Beginning of a new try-range?
416 RangeMapType::iterator L = PadMap.find(BeginLabel);
417 if (L == PadMap.end())
418 // Nope, it was just some random label.
421 PadRange P = L->second;
422 const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
423 assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
424 "Inconsistent landing pad map!");
426 // If some instruction between the previous try-range and this one may
427 // throw, create a call-site entry with no landing pad for the region
428 // between the try-ranges.
429 if (SawPotentiallyThrowing) {
430 CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
431 CallSites.push_back(Site);
432 PreviousIsInvoke = false;
435 LastLabel = LandingPad->EndLabels[P.RangeIndex];
436 assert(BeginLabel && LastLabel && "Invalid landing pad!");
438 if (LandingPad->LandingPadLabel) {
439 // This try-range is for an invoke.
440 CallSiteEntry Site = {BeginLabel, LastLabel,
441 LandingPad->LandingPadLabel,
442 FirstActions[P.PadIndex]};
444 // Try to merge with the previous call-site.
445 if (PreviousIsInvoke) {
446 CallSiteEntry &Prev = CallSites.back();
447 if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
448 // Extend the range of the previous entry.
449 Prev.EndLabel = Site.EndLabel;
454 // Otherwise, create a new call-site.
455 CallSites.push_back(Site);
456 PreviousIsInvoke = true;
459 PreviousIsInvoke = false;
464 // If some instruction between the previous try-range and the end of the
465 // function may throw, create a call-site entry with no landing pad for the
466 // region following the try-range.
467 if (SawPotentiallyThrowing) {
468 CallSiteEntry Site = {LastLabel, 0, 0, 0};
469 CallSites.push_back(Site);
473 void DwarfException::EmitExceptionTable() {
474 const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
475 const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
476 const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
477 if (PadInfos.empty()) return;
479 // Sort the landing pads in order of their type ids. This is used to fold
480 // duplicate actions.
481 SmallVector<const LandingPadInfo *, 64> LandingPads;
482 LandingPads.reserve(PadInfos.size());
484 for (unsigned i = 0, N = PadInfos.size(); i != N; ++i)
485 LandingPads.push_back(&PadInfos[i]);
487 std::sort(LandingPads.begin(), LandingPads.end(), PadLT);
489 // Compute the actions table and gather the first action index for each
491 SmallVector<ActionEntry, 32> Actions;
492 SmallVector<unsigned, 64> FirstActions;
493 unsigned SizeActions = ComputeActionsTable(LandingPads, Actions, FirstActions);
495 // Invokes and nounwind calls have entries in PadMap (due to being bracketed
496 // by try-range labels when lowered). Ordinary calls do not, so appropriate
497 // try-ranges for them need be deduced.
499 for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
500 const LandingPadInfo *LandingPad = LandingPads[i];
501 for (unsigned j = 0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
502 unsigned BeginLabel = LandingPad->BeginLabels[j];
503 assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
504 PadRange P = { i, j };
505 PadMap[BeginLabel] = P;
509 // Compute the call-site table.
510 SmallVector<CallSiteEntry, 64> CallSites;
511 ComputeCallSiteTable(CallSites, PadMap, LandingPads, FirstActions);
516 const unsigned SiteStartSize = sizeof(int32_t); // DW_EH_PE_udata4
517 const unsigned SiteLengthSize = sizeof(int32_t); // DW_EH_PE_udata4
518 const unsigned LandingPadSize = sizeof(int32_t); // DW_EH_PE_udata4
519 unsigned SizeSites = CallSites.size() * (SiteStartSize +
522 for (unsigned i = 0, e = CallSites.size(); i < e; ++i)
523 SizeSites += TargetAsmInfo::getULEB128Size(CallSites[i].Action);
526 const unsigned TypeInfoSize = TD->getPointerSize(); // DW_EH_PE_absptr
527 unsigned SizeTypes = TypeInfos.size() * TypeInfoSize;
529 unsigned TypeOffset = sizeof(int8_t) + // Call site format
530 TargetAsmInfo::getULEB128Size(SizeSites) + // Call-site table length
531 SizeSites + SizeActions + SizeTypes;
533 unsigned TotalSize = sizeof(int8_t) + // LPStart format
534 sizeof(int8_t) + // TType format
535 TargetAsmInfo::getULEB128Size(TypeOffset) + // TType base offset
538 unsigned SizeAlign = (4 - TotalSize) & 3;
540 // Begin the exception table.
541 Asm->SwitchToDataSection(TAI->getDwarfExceptionSection());
542 Asm->EmitAlignment(2, 0, 0, false);
543 O << "GCC_except_table" << SubprogramCount << ":\n";
545 for (unsigned i = 0; i != SizeAlign; ++i) {
550 EmitLabel("exception", SubprogramCount);
553 Asm->EmitInt8(dwarf::DW_EH_PE_omit);
554 Asm->EOL("LPStart format (DW_EH_PE_omit)");
557 if (!TypeInfos.empty() || !FilterIds.empty()) {
558 Asm->EmitInt8(TAI->PreferredEHDataFormat(DwarfEncoding::Data, true));
559 // FIXME: The comment here should correspond with what PreferredEHDataFormat
561 Asm->EOL("TType format (DW_EH_PE_xxxxx)");
562 Asm->EmitULEB128Bytes(TypeOffset);
563 Asm->EOL("TType base offset");
565 Asm->EmitInt8(dwarf::DW_EH_PE_omit);
566 Asm->EOL("TType format (DW_EH_PE_omit)");
569 Asm->EmitInt8(dwarf::DW_EH_PE_absptr);
570 Asm->EOL("TType format (DW_EH_PE_absptr)");
573 Asm->EmitInt8(dwarf::DW_EH_PE_udata4);
574 Asm->EOL("Call site format (DW_EH_PE_udata4)");
575 Asm->EmitULEB128Bytes(SizeSites);
576 Asm->EOL("Call-site table length");
578 // Emit the landing pad site information.
579 for (SmallVectorImpl<CallSiteEntry>::const_iterator
580 I = CallSites.begin(), E = CallSites.end(); I != E; ++I) {
581 const CallSiteEntry &S = *I;
582 const char *BeginTag;
583 unsigned BeginNumber;
586 BeginTag = "eh_func_begin";
587 BeginNumber = SubprogramCount;
590 BeginNumber = S.BeginLabel;
593 EmitSectionOffset(BeginTag, "eh_func_begin", BeginNumber, SubprogramCount,
595 Asm->EOL("Region start");
598 EmitDifference("eh_func_end", SubprogramCount, BeginTag, BeginNumber,
601 EmitDifference("label", S.EndLabel, BeginTag, BeginNumber, true);
603 Asm->EOL("Region length");
608 EmitSectionOffset("label", "eh_func_begin", S.PadLabel, SubprogramCount,
611 Asm->EOL("Landing pad");
613 Asm->EmitULEB128Bytes(S.Action);
618 for (SmallVectorImpl<ActionEntry>::const_iterator
619 I = Actions.begin(), E = Actions.end(); I != E; ++I) {
620 const ActionEntry &Action = *I;
621 Asm->EmitSLEB128Bytes(Action.ValueForTypeID);
622 Asm->EOL("TypeInfo index");
623 Asm->EmitSLEB128Bytes(Action.NextAction);
624 Asm->EOL("Next action");
627 // Emit the type ids.
628 for (std::vector<GlobalVariable *>::const_reverse_iterator
629 I = TypeInfos.rbegin(), E = TypeInfos.rend(); I != E; ++I) {
630 GlobalVariable *GV = *I;
635 O << Asm->getGlobalLinkName(GV, GLN);
640 Asm->EOL("TypeInfo");
643 // Emit the filter typeids.
644 for (std::vector<unsigned>::const_iterator
645 I = FilterIds.begin(), E = FilterIds.end(); I < E; ++I) {
646 unsigned TypeID = *I;
647 Asm->EmitULEB128Bytes(TypeID);
648 Asm->EOL("Filter TypeInfo index");
651 Asm->EmitAlignment(2, 0, 0, false);
654 /// EndModule - Emit all exception information that should come after the
656 void DwarfException::EndModule() {
657 if (TimePassesIsEnabled)
658 ExceptionTimer->startTimer();
660 if (shouldEmitMovesModule || shouldEmitTableModule) {
661 const std::vector<Function *> Personalities = MMI->getPersonalities();
662 for (unsigned i = 0; i < Personalities.size(); ++i)
663 EmitCommonEHFrame(Personalities[i], i);
665 for (std::vector<FunctionEHFrameInfo>::iterator I = EHFrames.begin(),
666 E = EHFrames.end(); I != E; ++I)
670 if (TimePassesIsEnabled)
671 ExceptionTimer->stopTimer();
674 /// BeginFunction - Gather pre-function exception information. Assumes being
675 /// emitted immediately after the function entry point.
676 void DwarfException::BeginFunction(MachineFunction *MF) {
677 if (TimePassesIsEnabled)
678 ExceptionTimer->startTimer();
681 shouldEmitTable = shouldEmitMoves = false;
683 if (MMI && TAI->doesSupportExceptionHandling()) {
684 // Map all labels and get rid of any dead landing pads.
685 MMI->TidyLandingPads();
687 // If any landing pads survive, we need an EH table.
688 if (MMI->getLandingPads().size())
689 shouldEmitTable = true;
691 // See if we need frame move info.
692 if (!MF->getFunction()->doesNotThrow() || UnwindTablesMandatory)
693 shouldEmitMoves = true;
695 if (shouldEmitMoves || shouldEmitTable)
696 // Assumes in correct section after the entry point.
697 EmitLabel("eh_func_begin", ++SubprogramCount);
700 shouldEmitTableModule |= shouldEmitTable;
701 shouldEmitMovesModule |= shouldEmitMoves;
703 if (TimePassesIsEnabled)
704 ExceptionTimer->stopTimer();
707 /// EndFunction - Gather and emit post-function exception information.
709 void DwarfException::EndFunction() {
710 if (TimePassesIsEnabled)
711 ExceptionTimer->startTimer();
713 if (shouldEmitMoves || shouldEmitTable) {
714 EmitLabel("eh_func_end", SubprogramCount);
715 EmitExceptionTable();
717 // Save EH frame information
719 FunctionEHFrameInfo(getAsm()->getCurrentFunctionEHName(MF),
721 MMI->getPersonalityIndex(),
722 MF->getFrameInfo()->hasCalls(),
723 !MMI->getLandingPads().empty(),
724 MMI->getFrameMoves(),
728 if (TimePassesIsEnabled)
729 ExceptionTimer->stopTimer();