LLVM 19.0.0git
AsmPrinter.cpp
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1//===- AsmPrinter.cpp - Common AsmPrinter code ----------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the AsmPrinter class.
10//
11//===----------------------------------------------------------------------===//
12
14#include "CodeViewDebug.h"
15#include "DwarfDebug.h"
16#include "DwarfException.h"
17#include "PseudoProbePrinter.h"
18#include "WasmException.h"
19#include "WinCFGuard.h"
20#include "WinException.h"
21#include "llvm/ADT/APFloat.h"
22#include "llvm/ADT/APInt.h"
23#include "llvm/ADT/DenseMap.h"
24#include "llvm/ADT/STLExtras.h"
28#include "llvm/ADT/Statistic.h"
30#include "llvm/ADT/StringRef.h"
32#include "llvm/ADT/Twine.h"
64#include "llvm/Config/config.h"
65#include "llvm/IR/BasicBlock.h"
66#include "llvm/IR/Comdat.h"
67#include "llvm/IR/Constant.h"
68#include "llvm/IR/Constants.h"
69#include "llvm/IR/DataLayout.h"
73#include "llvm/IR/Function.h"
74#include "llvm/IR/GCStrategy.h"
75#include "llvm/IR/GlobalAlias.h"
76#include "llvm/IR/GlobalIFunc.h"
78#include "llvm/IR/GlobalValue.h"
80#include "llvm/IR/Instruction.h"
81#include "llvm/IR/Mangler.h"
82#include "llvm/IR/Metadata.h"
83#include "llvm/IR/Module.h"
84#include "llvm/IR/Operator.h"
85#include "llvm/IR/PseudoProbe.h"
86#include "llvm/IR/Type.h"
87#include "llvm/IR/Value.h"
88#include "llvm/IR/ValueHandle.h"
89#include "llvm/MC/MCAsmInfo.h"
90#include "llvm/MC/MCContext.h"
92#include "llvm/MC/MCExpr.h"
93#include "llvm/MC/MCInst.h"
94#include "llvm/MC/MCSection.h"
99#include "llvm/MC/MCStreamer.h"
101#include "llvm/MC/MCSymbol.h"
102#include "llvm/MC/MCSymbolELF.h"
104#include "llvm/MC/MCValue.h"
105#include "llvm/MC/SectionKind.h"
106#include "llvm/Object/ELFTypes.h"
107#include "llvm/Pass.h"
109#include "llvm/Support/Casting.h"
113#include "llvm/Support/Format.h"
115#include "llvm/Support/Path.h"
116#include "llvm/Support/Timer.h"
122#include <algorithm>
123#include <cassert>
124#include <cinttypes>
125#include <cstdint>
126#include <iterator>
127#include <memory>
128#include <optional>
129#include <string>
130#include <utility>
131#include <vector>
132
133using namespace llvm;
134
135#define DEBUG_TYPE "asm-printer"
136
137// This is a replication of fields of object::PGOAnalysisMap::Features. It
138// should match the order of the fields so that
139// `object::PGOAnalysisMap::Features::decode(PgoAnalysisMapFeatures.getBits())`
140// succeeds.
143 BBFreq,
144 BrProb,
145};
147 "pgo-analysis-map", cl::Hidden, cl::CommaSeparated,
149 "func-entry-count", "Function Entry Count"),
151 "Basic Block Frequency"),
153 "Branch Probability")),
154 cl::desc(
155 "Enable extended information within the SHT_LLVM_BB_ADDR_MAP that is "
156 "extracted from PGO related analysis."));
157
158const char DWARFGroupName[] = "dwarf";
159const char DWARFGroupDescription[] = "DWARF Emission";
160const char DbgTimerName[] = "emit";
161const char DbgTimerDescription[] = "Debug Info Emission";
162const char EHTimerName[] = "write_exception";
163const char EHTimerDescription[] = "DWARF Exception Writer";
164const char CFGuardName[] = "Control Flow Guard";
165const char CFGuardDescription[] = "Control Flow Guard";
166const char CodeViewLineTablesGroupName[] = "linetables";
167const char CodeViewLineTablesGroupDescription[] = "CodeView Line Tables";
168const char PPTimerName[] = "emit";
169const char PPTimerDescription[] = "Pseudo Probe Emission";
170const char PPGroupName[] = "pseudo probe";
171const char PPGroupDescription[] = "Pseudo Probe Emission";
172
173STATISTIC(EmittedInsts, "Number of machine instrs printed");
174
175char AsmPrinter::ID = 0;
176
177namespace {
178class AddrLabelMapCallbackPtr final : CallbackVH {
179 AddrLabelMap *Map = nullptr;
180
181public:
182 AddrLabelMapCallbackPtr() = default;
183 AddrLabelMapCallbackPtr(Value *V) : CallbackVH(V) {}
184
185 void setPtr(BasicBlock *BB) {
187 }
188
189 void setMap(AddrLabelMap *map) { Map = map; }
190
191 void deleted() override;
192 void allUsesReplacedWith(Value *V2) override;
193};
194} // namespace
195
197 MCContext &Context;
198 struct AddrLabelSymEntry {
199 /// The symbols for the label.
201
202 Function *Fn; // The containing function of the BasicBlock.
203 unsigned Index; // The index in BBCallbacks for the BasicBlock.
204 };
205
206 DenseMap<AssertingVH<BasicBlock>, AddrLabelSymEntry> AddrLabelSymbols;
207
208 /// Callbacks for the BasicBlock's that we have entries for. We use this so
209 /// we get notified if a block is deleted or RAUWd.
210 std::vector<AddrLabelMapCallbackPtr> BBCallbacks;
211
212 /// This is a per-function list of symbols whose corresponding BasicBlock got
213 /// deleted. These symbols need to be emitted at some point in the file, so
214 /// AsmPrinter emits them after the function body.
215 DenseMap<AssertingVH<Function>, std::vector<MCSymbol *>>
216 DeletedAddrLabelsNeedingEmission;
217
218public:
219 AddrLabelMap(MCContext &context) : Context(context) {}
220
222 assert(DeletedAddrLabelsNeedingEmission.empty() &&
223 "Some labels for deleted blocks never got emitted");
224 }
225
227
229 std::vector<MCSymbol *> &Result);
230
233};
234
236 assert(BB->hasAddressTaken() &&
237 "Shouldn't get label for block without address taken");
238 AddrLabelSymEntry &Entry = AddrLabelSymbols[BB];
239
240 // If we already had an entry for this block, just return it.
241 if (!Entry.Symbols.empty()) {
242 assert(BB->getParent() == Entry.Fn && "Parent changed");
243 return Entry.Symbols;
244 }
245
246 // Otherwise, this is a new entry, create a new symbol for it and add an
247 // entry to BBCallbacks so we can be notified if the BB is deleted or RAUWd.
248 BBCallbacks.emplace_back(BB);
249 BBCallbacks.back().setMap(this);
250 Entry.Index = BBCallbacks.size() - 1;
251 Entry.Fn = BB->getParent();
253 : Context.createTempSymbol();
254 Entry.Symbols.push_back(Sym);
255 return Entry.Symbols;
256}
257
258/// If we have any deleted symbols for F, return them.
260 Function *F, std::vector<MCSymbol *> &Result) {
261 DenseMap<AssertingVH<Function>, std::vector<MCSymbol *>>::iterator I =
262 DeletedAddrLabelsNeedingEmission.find(F);
263
264 // If there are no entries for the function, just return.
265 if (I == DeletedAddrLabelsNeedingEmission.end())
266 return;
267
268 // Otherwise, take the list.
269 std::swap(Result, I->second);
270 DeletedAddrLabelsNeedingEmission.erase(I);
271}
272
273//===- Address of Block Management ----------------------------------------===//
274
277 // Lazily create AddrLabelSymbols.
278 if (!AddrLabelSymbols)
279 AddrLabelSymbols = std::make_unique<AddrLabelMap>(OutContext);
280 return AddrLabelSymbols->getAddrLabelSymbolToEmit(
281 const_cast<BasicBlock *>(BB));
282}
283
285 const Function *F, std::vector<MCSymbol *> &Result) {
286 // If no blocks have had their addresses taken, we're done.
287 if (!AddrLabelSymbols)
288 return;
289 return AddrLabelSymbols->takeDeletedSymbolsForFunction(
290 const_cast<Function *>(F), Result);
291}
292
294 // If the block got deleted, there is no need for the symbol. If the symbol
295 // was already emitted, we can just forget about it, otherwise we need to
296 // queue it up for later emission when the function is output.
297 AddrLabelSymEntry Entry = std::move(AddrLabelSymbols[BB]);
298 AddrLabelSymbols.erase(BB);
299 assert(!Entry.Symbols.empty() && "Didn't have a symbol, why a callback?");
300 BBCallbacks[Entry.Index] = nullptr; // Clear the callback.
301
302#if !LLVM_MEMORY_SANITIZER_BUILD
303 // BasicBlock is destroyed already, so this access is UB detectable by msan.
304 assert((BB->getParent() == nullptr || BB->getParent() == Entry.Fn) &&
305 "Block/parent mismatch");
306#endif
307
308 for (MCSymbol *Sym : Entry.Symbols) {
309 if (Sym->isDefined())
310 return;
311
312 // If the block is not yet defined, we need to emit it at the end of the
313 // function. Add the symbol to the DeletedAddrLabelsNeedingEmission list
314 // for the containing Function. Since the block is being deleted, its
315 // parent may already be removed, we have to get the function from 'Entry'.
316 DeletedAddrLabelsNeedingEmission[Entry.Fn].push_back(Sym);
317 }
318}
319
321 // Get the entry for the RAUW'd block and remove it from our map.
322 AddrLabelSymEntry OldEntry = std::move(AddrLabelSymbols[Old]);
323 AddrLabelSymbols.erase(Old);
324 assert(!OldEntry.Symbols.empty() && "Didn't have a symbol, why a callback?");
325
326 AddrLabelSymEntry &NewEntry = AddrLabelSymbols[New];
327
328 // If New is not address taken, just move our symbol over to it.
329 if (NewEntry.Symbols.empty()) {
330 BBCallbacks[OldEntry.Index].setPtr(New); // Update the callback.
331 NewEntry = std::move(OldEntry); // Set New's entry.
332 return;
333 }
334
335 BBCallbacks[OldEntry.Index] = nullptr; // Update the callback.
336
337 // Otherwise, we need to add the old symbols to the new block's set.
338 llvm::append_range(NewEntry.Symbols, OldEntry.Symbols);
339}
340
341void AddrLabelMapCallbackPtr::deleted() {
342 Map->UpdateForDeletedBlock(cast<BasicBlock>(getValPtr()));
343}
344
345void AddrLabelMapCallbackPtr::allUsesReplacedWith(Value *V2) {
346 Map->UpdateForRAUWBlock(cast<BasicBlock>(getValPtr()), cast<BasicBlock>(V2));
347}
348
349/// getGVAlignment - Return the alignment to use for the specified global
350/// value. This rounds up to the preferred alignment if possible and legal.
352 Align InAlign) {
353 Align Alignment;
354 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
355 Alignment = DL.getPreferredAlign(GVar);
356
357 // If InAlign is specified, round it to it.
358 if (InAlign > Alignment)
359 Alignment = InAlign;
360
361 // If the GV has a specified alignment, take it into account.
362 const MaybeAlign GVAlign(GV->getAlign());
363 if (!GVAlign)
364 return Alignment;
365
366 assert(GVAlign && "GVAlign must be set");
367
368 // If the GVAlign is larger than NumBits, or if we are required to obey
369 // NumBits because the GV has an assigned section, obey it.
370 if (*GVAlign > Alignment || GV->hasSection())
371 Alignment = *GVAlign;
372 return Alignment;
373}
374
375AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
376 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
377 OutContext(Streamer->getContext()), OutStreamer(std::move(Streamer)),
378 SM(*this) {
379 VerboseAsm = OutStreamer->isVerboseAsm();
380 DwarfUsesRelocationsAcrossSections =
382}
383
385 assert(!DD && Handlers.size() == NumUserHandlers &&
386 "Debug/EH info didn't get finalized");
387}
388
390 return TM.isPositionIndependent();
391}
392
393/// getFunctionNumber - Return a unique ID for the current function.
395 return MF->getFunctionNumber();
396}
397
399 return *TM.getObjFileLowering();
400}
401
403 assert(MMI && "MMI could not be nullptr!");
404 return MMI->getModule()->getDataLayout();
405}
406
407// Do not use the cached DataLayout because some client use it without a Module
408// (dsymutil, llvm-dwarfdump).
410 return TM.getPointerSize(0); // FIXME: Default address space
411}
412
414 assert(MF && "getSubtargetInfo requires a valid MachineFunction!");
416}
417
420}
421
423 if (DD) {
424 assert(OutStreamer->hasRawTextSupport() &&
425 "Expected assembly output mode.");
426 // This is NVPTX specific and it's unclear why.
427 // PR51079: If we have code without debug information we need to give up.
429 if (!MFSP)
430 return;
431 (void)DD->emitInitialLocDirective(MF, /*CUID=*/0);
432 }
433}
434
435/// getCurrentSection() - Return the current section we are emitting to.
437 return OutStreamer->getCurrentSectionOnly();
438}
439
441 AU.setPreservesAll();
447}
448
450 auto *MMIWP = getAnalysisIfAvailable<MachineModuleInfoWrapperPass>();
451 MMI = MMIWP ? &MMIWP->getMMI() : nullptr;
452 HasSplitStack = false;
453 HasNoSplitStack = false;
454
455 AddrLabelSymbols = nullptr;
456
457 // Initialize TargetLoweringObjectFile.
459 .Initialize(OutContext, TM);
460
462 .getModuleMetadata(M);
463
464 // On AIX, we delay emitting any section information until
465 // after emitting the .file pseudo-op. This allows additional
466 // information (such as the embedded command line) to be associated
467 // with all sections in the object file rather than a single section.
469 OutStreamer->initSections(false, *TM.getMCSubtargetInfo());
470
471 // Emit the version-min deployment target directive if needed.
472 //
473 // FIXME: If we end up with a collection of these sorts of Darwin-specific
474 // or ELF-specific things, it may make sense to have a platform helper class
475 // that will work with the target helper class. For now keep it here, as the
476 // alternative is duplicated code in each of the target asm printers that
477 // use the directive, where it would need the same conditionalization
478 // anyway.
479 const Triple &Target = TM.getTargetTriple();
480 Triple TVT(M.getDarwinTargetVariantTriple());
481 OutStreamer->emitVersionForTarget(
482 Target, M.getSDKVersion(),
483 M.getDarwinTargetVariantTriple().empty() ? nullptr : &TVT,
484 M.getDarwinTargetVariantSDKVersion());
485
486 // Allow the target to emit any magic that it wants at the start of the file.
488
489 // Very minimal debug info. It is ignored if we emit actual debug info. If we
490 // don't, this at least helps the user find where a global came from.
492 // .file "foo.c"
493
494 SmallString<128> FileName;
496 FileName = llvm::sys::path::filename(M.getSourceFileName());
497 else
498 FileName = M.getSourceFileName();
499 if (MAI->hasFourStringsDotFile()) {
500#ifdef PACKAGE_VENDOR
501 const char VerStr[] =
502 PACKAGE_VENDOR " " PACKAGE_NAME " version " PACKAGE_VERSION;
503#else
504 const char VerStr[] = PACKAGE_NAME " version " PACKAGE_VERSION;
505#endif
506 // TODO: Add timestamp and description.
507 OutStreamer->emitFileDirective(FileName, VerStr, "", "");
508 } else {
509 OutStreamer->emitFileDirective(FileName);
510 }
511 }
512
513 // On AIX, emit bytes for llvm.commandline metadata after .file so that the
514 // C_INFO symbol is preserved if any csect is kept by the linker.
516 emitModuleCommandLines(M);
517 // Now we can generate section information.
518 OutStreamer->initSections(false, *TM.getMCSubtargetInfo());
519
520 // To work around an AIX assembler and/or linker bug, generate
521 // a rename for the default text-section symbol name. This call has
522 // no effect when generating object code directly.
523 MCSection *TextSection =
524 OutStreamer->getContext().getObjectFileInfo()->getTextSection();
525 MCSymbolXCOFF *XSym =
526 static_cast<MCSectionXCOFF *>(TextSection)->getQualNameSymbol();
527 if (XSym->hasRename())
528 OutStreamer->emitXCOFFRenameDirective(XSym, XSym->getSymbolTableName());
529 }
530
531 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
532 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
533 for (const auto &I : *MI)
534 if (GCMetadataPrinter *MP = getOrCreateGCPrinter(*I))
535 MP->beginAssembly(M, *MI, *this);
536
537 // Emit module-level inline asm if it exists.
538 if (!M.getModuleInlineAsm().empty()) {
539 OutStreamer->AddComment("Start of file scope inline assembly");
540 OutStreamer->addBlankLine();
541 emitInlineAsm(
542 M.getModuleInlineAsm() + "\n", *TM.getMCSubtargetInfo(),
543 TM.Options.MCOptions, nullptr,
545 OutStreamer->AddComment("End of file scope inline assembly");
546 OutStreamer->addBlankLine();
547 }
548
550 bool EmitCodeView = M.getCodeViewFlag();
551 if (EmitCodeView && TM.getTargetTriple().isOSWindows()) {
552 Handlers.emplace_back(std::make_unique<CodeViewDebug>(this),
556 }
557 if (!EmitCodeView || M.getDwarfVersion()) {
558 assert(MMI && "MMI could not be nullptr here!");
559 if (MMI->hasDebugInfo()) {
560 DD = new DwarfDebug(this);
561 Handlers.emplace_back(std::unique_ptr<DwarfDebug>(DD), DbgTimerName,
564 }
565 }
566 }
567
568 if (M.getNamedMetadata(PseudoProbeDescMetadataName)) {
569 PP = new PseudoProbeHandler(this);
570 Handlers.emplace_back(std::unique_ptr<PseudoProbeHandler>(PP), PPTimerName,
572 }
573
574 switch (MAI->getExceptionHandlingType()) {
576 // We may want to emit CFI for debug.
577 [[fallthrough]];
581 for (auto &F : M.getFunctionList()) {
583 ModuleCFISection = getFunctionCFISectionType(F);
584 // If any function needsUnwindTableEntry(), it needs .eh_frame and hence
585 // the module needs .eh_frame. If we have found that case, we are done.
586 if (ModuleCFISection == CFISection::EH)
587 break;
588 }
590 usesCFIWithoutEH() || ModuleCFISection != CFISection::EH);
591 break;
592 default:
593 break;
594 }
595
596 EHStreamer *ES = nullptr;
597 switch (MAI->getExceptionHandlingType()) {
599 if (!usesCFIWithoutEH())
600 break;
601 [[fallthrough]];
605 ES = new DwarfCFIException(this);
606 break;
608 ES = new ARMException(this);
609 break;
611 switch (MAI->getWinEHEncodingType()) {
612 default: llvm_unreachable("unsupported unwinding information encoding");
614 break;
617 ES = new WinException(this);
618 break;
619 }
620 break;
622 ES = new WasmException(this);
623 break;
625 ES = new AIXException(this);
626 break;
627 }
628 if (ES)
629 Handlers.emplace_back(std::unique_ptr<EHStreamer>(ES), EHTimerName,
632
633 // Emit tables for any value of cfguard flag (i.e. cfguard=1 or cfguard=2).
634 if (mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("cfguard")))
635 Handlers.emplace_back(std::make_unique<WinCFGuard>(this), CFGuardName,
638
639 for (const HandlerInfo &HI : Handlers) {
640 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
641 HI.TimerGroupDescription, TimePassesIsEnabled);
642 HI.Handler->beginModule(&M);
643 }
644
645 return false;
646}
647
648static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
650 return false;
651
652 return GV->canBeOmittedFromSymbolTable();
653}
654
655void AsmPrinter::emitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
657 switch (Linkage) {
663 if (MAI->hasWeakDefDirective()) {
664 // .globl _foo
665 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Global);
666
667 if (!canBeHidden(GV, *MAI))
668 // .weak_definition _foo
669 OutStreamer->emitSymbolAttribute(GVSym, MCSA_WeakDefinition);
670 else
671 OutStreamer->emitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
672 } else if (MAI->avoidWeakIfComdat() && GV->hasComdat()) {
673 // .globl _foo
674 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Global);
675 //NOTE: linkonce is handled by the section the symbol was assigned to.
676 } else {
677 // .weak _foo
678 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Weak);
679 }
680 return;
682 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Global);
683 return;
686 return;
690 llvm_unreachable("Should never emit this");
691 }
692 llvm_unreachable("Unknown linkage type!");
693}
694
696 const GlobalValue *GV) const {
697 TM.getNameWithPrefix(Name, GV, getObjFileLowering().getMangler());
698}
699
701 return TM.getSymbol(GV);
702}
703
705 // On ELF, use .Lfoo$local if GV is a non-interposable GlobalObject with an
706 // exact definion (intersection of GlobalValue::hasExactDefinition() and
707 // !isInterposable()). These linkages include: external, appending, internal,
708 // private. It may be profitable to use a local alias for external. The
709 // assembler would otherwise be conservative and assume a global default
710 // visibility symbol can be interposable, even if the code generator already
711 // assumed it.
713 const Module &M = *GV.getParent();
715 M.getPIELevel() == PIELevel::Default && GV.isDSOLocal())
716 return getSymbolWithGlobalValueBase(&GV, "$local");
717 }
718 return TM.getSymbol(&GV);
719}
720
721/// EmitGlobalVariable - Emit the specified global variable to the .s file.
723 bool IsEmuTLSVar = TM.useEmulatedTLS() && GV->isThreadLocal();
724 assert(!(IsEmuTLSVar && GV->hasCommonLinkage()) &&
725 "No emulated TLS variables in the common section");
726
727 // Never emit TLS variable xyz in emulated TLS model.
728 // The initialization value is in __emutls_t.xyz instead of xyz.
729 if (IsEmuTLSVar)
730 return;
731
732 if (GV->hasInitializer()) {
733 // Check to see if this is a special global used by LLVM, if so, emit it.
734 if (emitSpecialLLVMGlobal(GV))
735 return;
736
737 // Skip the emission of global equivalents. The symbol can be emitted later
738 // on by emitGlobalGOTEquivs in case it turns out to be needed.
739 if (GlobalGOTEquivs.count(getSymbol(GV)))
740 return;
741
742 if (isVerbose()) {
743 // When printing the control variable __emutls_v.*,
744 // we don't need to print the original TLS variable name.
745 GV->printAsOperand(OutStreamer->getCommentOS(),
746 /*PrintType=*/false, GV->getParent());
747 OutStreamer->getCommentOS() << '\n';
748 }
749 }
750
751 MCSymbol *GVSym = getSymbol(GV);
752 MCSymbol *EmittedSym = GVSym;
753
754 // getOrCreateEmuTLSControlSym only creates the symbol with name and default
755 // attributes.
756 // GV's or GVSym's attributes will be used for the EmittedSym.
757 emitVisibility(EmittedSym, GV->getVisibility(), !GV->isDeclaration());
758
759 if (GV->isTagged()) {
761
762 if (T.getArch() != Triple::aarch64 || !T.isAndroid())
764 "tagged symbols (-fsanitize=memtag-globals) are "
765 "only supported on AArch64 Android");
766 OutStreamer->emitSymbolAttribute(EmittedSym, MAI->getMemtagAttr());
767 }
768
769 if (!GV->hasInitializer()) // External globals require no extra code.
770 return;
771
772 GVSym->redefineIfPossible();
773 if (GVSym->isDefined() || GVSym->isVariable())
774 OutContext.reportError(SMLoc(), "symbol '" + Twine(GVSym->getName()) +
775 "' is already defined");
776
778 OutStreamer->emitSymbolAttribute(EmittedSym, MCSA_ELF_TypeObject);
779
781
782 const DataLayout &DL = GV->getParent()->getDataLayout();
783 uint64_t Size = DL.getTypeAllocSize(GV->getValueType());
784
785 // If the alignment is specified, we *must* obey it. Overaligning a global
786 // with a specified alignment is a prompt way to break globals emitted to
787 // sections and expected to be contiguous (e.g. ObjC metadata).
788 const Align Alignment = getGVAlignment(GV, DL);
789
790 for (const HandlerInfo &HI : Handlers) {
791 NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
792 HI.TimerGroupName, HI.TimerGroupDescription,
794 HI.Handler->setSymbolSize(GVSym, Size);
795 }
796
797 // Handle common symbols
798 if (GVKind.isCommon()) {
799 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
800 // .comm _foo, 42, 4
801 OutStreamer->emitCommonSymbol(GVSym, Size, Alignment);
802 return;
803 }
804
805 // Determine to which section this global should be emitted.
806 MCSection *TheSection = getObjFileLowering().SectionForGlobal(GV, GVKind, TM);
807
808 // If we have a bss global going to a section that supports the
809 // zerofill directive, do so here.
810 if (GVKind.isBSS() && MAI->hasMachoZeroFillDirective() &&
811 TheSection->isVirtualSection()) {
812 if (Size == 0)
813 Size = 1; // zerofill of 0 bytes is undefined.
814 emitLinkage(GV, GVSym);
815 // .zerofill __DATA, __bss, _foo, 400, 5
816 OutStreamer->emitZerofill(TheSection, GVSym, Size, Alignment);
817 return;
818 }
819
820 // If this is a BSS local symbol and we are emitting in the BSS
821 // section use .lcomm/.comm directive.
822 if (GVKind.isBSSLocal() &&
823 getObjFileLowering().getBSSSection() == TheSection) {
824 if (Size == 0)
825 Size = 1; // .comm Foo, 0 is undefined, avoid it.
826
827 // Use .lcomm only if it supports user-specified alignment.
828 // Otherwise, while it would still be correct to use .lcomm in some
829 // cases (e.g. when Align == 1), the external assembler might enfore
830 // some -unknown- default alignment behavior, which could cause
831 // spurious differences between external and integrated assembler.
832 // Prefer to simply fall back to .local / .comm in this case.
834 // .lcomm _foo, 42
835 OutStreamer->emitLocalCommonSymbol(GVSym, Size, Alignment);
836 return;
837 }
838
839 // .local _foo
840 OutStreamer->emitSymbolAttribute(GVSym, MCSA_Local);
841 // .comm _foo, 42, 4
842 OutStreamer->emitCommonSymbol(GVSym, Size, Alignment);
843 return;
844 }
845
846 // Handle thread local data for mach-o which requires us to output an
847 // additional structure of data and mangle the original symbol so that we
848 // can reference it later.
849 //
850 // TODO: This should become an "emit thread local global" method on TLOF.
851 // All of this macho specific stuff should be sunk down into TLOFMachO and
852 // stuff like "TLSExtraDataSection" should no longer be part of the parent
853 // TLOF class. This will also make it more obvious that stuff like
854 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
855 // specific code.
856 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
857 // Emit the .tbss symbol
858 MCSymbol *MangSym =
859 OutContext.getOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
860
861 if (GVKind.isThreadBSS()) {
862 TheSection = getObjFileLowering().getTLSBSSSection();
863 OutStreamer->emitTBSSSymbol(TheSection, MangSym, Size, Alignment);
864 } else if (GVKind.isThreadData()) {
865 OutStreamer->switchSection(TheSection);
866
867 emitAlignment(Alignment, GV);
868 OutStreamer->emitLabel(MangSym);
869
871 GV->getInitializer());
872 }
873
874 OutStreamer->addBlankLine();
875
876 // Emit the variable struct for the runtime.
878
879 OutStreamer->switchSection(TLVSect);
880 // Emit the linkage here.
881 emitLinkage(GV, GVSym);
882 OutStreamer->emitLabel(GVSym);
883
884 // Three pointers in size:
885 // - __tlv_bootstrap - used to make sure support exists
886 // - spare pointer, used when mapped by the runtime
887 // - pointer to mangled symbol above with initializer
888 unsigned PtrSize = DL.getPointerTypeSize(GV->getType());
889 OutStreamer->emitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
890 PtrSize);
891 OutStreamer->emitIntValue(0, PtrSize);
892 OutStreamer->emitSymbolValue(MangSym, PtrSize);
893
894 OutStreamer->addBlankLine();
895 return;
896 }
897
898 MCSymbol *EmittedInitSym = GVSym;
899
900 OutStreamer->switchSection(TheSection);
901
902 emitLinkage(GV, EmittedInitSym);
903 emitAlignment(Alignment, GV);
904
905 OutStreamer->emitLabel(EmittedInitSym);
906 MCSymbol *LocalAlias = getSymbolPreferLocal(*GV);
907 if (LocalAlias != EmittedInitSym)
908 OutStreamer->emitLabel(LocalAlias);
909
911
913 // .size foo, 42
914 OutStreamer->emitELFSize(EmittedInitSym,
916
917 OutStreamer->addBlankLine();
918}
919
920/// Emit the directive and value for debug thread local expression
921///
922/// \p Value - The value to emit.
923/// \p Size - The size of the integer (in bytes) to emit.
924void AsmPrinter::emitDebugValue(const MCExpr *Value, unsigned Size) const {
925 OutStreamer->emitValue(Value, Size);
926}
927
928void AsmPrinter::emitFunctionHeaderComment() {}
929
930void AsmPrinter::emitFunctionPrefix(ArrayRef<const Constant *> Prefix) {
931 const Function &F = MF->getFunction();
933 for (auto &C : Prefix)
934 emitGlobalConstant(F.getParent()->getDataLayout(), C);
935 return;
936 }
937 // Preserving prefix-like data on platforms which use subsections-via-symbols
938 // is a bit tricky. Here we introduce a symbol for the prefix-like data
939 // and use the .alt_entry attribute to mark the function's real entry point
940 // as an alternative entry point to the symbol that precedes the function..
942
943 for (auto &C : Prefix) {
944 emitGlobalConstant(F.getParent()->getDataLayout(), C);
945 }
946
947 // Emit an .alt_entry directive for the actual function symbol.
948 OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_AltEntry);
949}
950
951/// EmitFunctionHeader - This method emits the header for the current
952/// function.
953void AsmPrinter::emitFunctionHeader() {
954 const Function &F = MF->getFunction();
955
956 if (isVerbose())
957 OutStreamer->getCommentOS()
958 << "-- Begin function "
959 << GlobalValue::dropLLVMManglingEscape(F.getName()) << '\n';
960
961 // Print out constants referenced by the function
963
964 // Print the 'header' of function.
965 // If basic block sections are desired, explicitly request a unique section
966 // for this function's entry block.
967 if (MF->front().isBeginSection())
968 MF->setSection(getObjFileLowering().getUniqueSectionForFunction(F, TM));
969 else
970 MF->setSection(getObjFileLowering().SectionForGlobal(&F, TM));
971 OutStreamer->switchSection(MF->getSection());
972
974 emitVisibility(CurrentFnSym, F.getVisibility());
975
978
982
984 OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
985
986 if (F.hasFnAttribute(Attribute::Cold))
987 OutStreamer->emitSymbolAttribute(CurrentFnSym, MCSA_Cold);
988
989 // Emit the prefix data.
990 if (F.hasPrefixData())
991 emitFunctionPrefix({F.getPrefixData()});
992
993 // Emit KCFI type information before patchable-function-prefix nops.
995
996 // Emit M NOPs for -fpatchable-function-entry=N,M where M>0. We arbitrarily
997 // place prefix data before NOPs.
998 unsigned PatchableFunctionPrefix = 0;
999 unsigned PatchableFunctionEntry = 0;
1000 (void)F.getFnAttribute("patchable-function-prefix")
1001 .getValueAsString()
1002 .getAsInteger(10, PatchableFunctionPrefix);
1003 (void)F.getFnAttribute("patchable-function-entry")
1004 .getValueAsString()
1005 .getAsInteger(10, PatchableFunctionEntry);
1006 if (PatchableFunctionPrefix) {
1010 emitNops(PatchableFunctionPrefix);
1011 } else if (PatchableFunctionEntry) {
1012 // May be reassigned when emitting the body, to reference the label after
1013 // the initial BTI (AArch64) or endbr32/endbr64 (x86).
1015 }
1016
1017 // Emit the function prologue data for the indirect call sanitizer.
1018 if (const MDNode *MD = F.getMetadata(LLVMContext::MD_func_sanitize)) {
1019 assert(MD->getNumOperands() == 2);
1020
1021 auto *PrologueSig = mdconst::extract<Constant>(MD->getOperand(0));
1022 auto *TypeHash = mdconst::extract<Constant>(MD->getOperand(1));
1023 emitFunctionPrefix({PrologueSig, TypeHash});
1024 }
1025
1026 if (isVerbose()) {
1027 F.printAsOperand(OutStreamer->getCommentOS(),
1028 /*PrintType=*/false, F.getParent());
1029 emitFunctionHeaderComment();
1030 OutStreamer->getCommentOS() << '\n';
1031 }
1032
1033 // Emit the function descriptor. This is a virtual function to allow targets
1034 // to emit their specific function descriptor. Right now it is only used by
1035 // the AIX target. The PowerPC 64-bit V1 ELF target also uses function
1036 // descriptors and should be converted to use this hook as well.
1039
1040 // Emit the CurrentFnSym. This is a virtual function to allow targets to do
1041 // their wild and crazy things as required.
1043
1044 // If the function had address-taken blocks that got deleted, then we have
1045 // references to the dangling symbols. Emit them at the start of the function
1046 // so that we don't get references to undefined symbols.
1047 std::vector<MCSymbol*> DeadBlockSyms;
1048 takeDeletedSymbolsForFunction(&F, DeadBlockSyms);
1049 for (MCSymbol *DeadBlockSym : DeadBlockSyms) {
1050 OutStreamer->AddComment("Address taken block that was later removed");
1051 OutStreamer->emitLabel(DeadBlockSym);
1052 }
1053
1054 if (CurrentFnBegin) {
1057 OutStreamer->emitLabel(CurPos);
1058 OutStreamer->emitAssignment(CurrentFnBegin,
1060 } else {
1061 OutStreamer->emitLabel(CurrentFnBegin);
1062 }
1063 }
1064
1065 // Emit pre-function debug and/or EH information.
1066 for (const HandlerInfo &HI : Handlers) {
1067 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1068 HI.TimerGroupDescription, TimePassesIsEnabled);
1069 HI.Handler->beginFunction(MF);
1070 }
1071 for (const HandlerInfo &HI : Handlers) {
1072 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1073 HI.TimerGroupDescription, TimePassesIsEnabled);
1074 HI.Handler->beginBasicBlockSection(MF->front());
1075 }
1076
1077 // Emit the prologue data.
1078 if (F.hasPrologueData())
1079 emitGlobalConstant(F.getParent()->getDataLayout(), F.getPrologueData());
1080}
1081
1082/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
1083/// function. This can be overridden by targets as required to do custom stuff.
1086
1087 // The function label could have already been emitted if two symbols end up
1088 // conflicting due to asm renaming. Detect this and emit an error.
1089 if (CurrentFnSym->isVariable())
1091 "' is a protected alias");
1092
1093 OutStreamer->emitLabel(CurrentFnSym);
1094
1097 if (Sym != CurrentFnSym) {
1098 cast<MCSymbolELF>(Sym)->setType(ELF::STT_FUNC);
1100 OutStreamer->emitLabel(Sym);
1102 OutStreamer->emitSymbolAttribute(Sym, MCSA_ELF_TypeFunction);
1103 }
1104 }
1105}
1106
1107/// emitComments - Pretty-print comments for instructions.
1108static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
1109 const MachineFunction *MF = MI.getMF();
1111
1112 // Check for spills and reloads
1113
1114 // We assume a single instruction only has a spill or reload, not
1115 // both.
1116 std::optional<LocationSize> Size;
1117 if ((Size = MI.getRestoreSize(TII))) {
1118 CommentOS << Size->getValue() << "-byte Reload\n";
1119 } else if ((Size = MI.getFoldedRestoreSize(TII))) {
1120 if (!Size->hasValue())
1121 CommentOS << "Unknown-size Folded Reload\n";
1122 else if (Size->getValue())
1123 CommentOS << Size->getValue() << "-byte Folded Reload\n";
1124 } else if ((Size = MI.getSpillSize(TII))) {
1125 CommentOS << Size->getValue() << "-byte Spill\n";
1126 } else if ((Size = MI.getFoldedSpillSize(TII))) {
1127 if (!Size->hasValue())
1128 CommentOS << "Unknown-size Folded Spill\n";
1129 else if (Size->getValue())
1130 CommentOS << Size->getValue() << "-byte Folded Spill\n";
1131 }
1132
1133 // Check for spill-induced copies
1134 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
1135 CommentOS << " Reload Reuse\n";
1136}
1137
1138/// emitImplicitDef - This method emits the specified machine instruction
1139/// that is an implicit def.
1141 Register RegNo = MI->getOperand(0).getReg();
1142
1143 SmallString<128> Str;
1145 OS << "implicit-def: "
1146 << printReg(RegNo, MF->getSubtarget().getRegisterInfo());
1147
1148 OutStreamer->AddComment(OS.str());
1149 OutStreamer->addBlankLine();
1150}
1151
1152static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
1153 std::string Str;
1155 OS << "kill:";
1156 for (const MachineOperand &Op : MI->operands()) {
1157 assert(Op.isReg() && "KILL instruction must have only register operands");
1158 OS << ' ' << (Op.isDef() ? "def " : "killed ")
1159 << printReg(Op.getReg(), AP.MF->getSubtarget().getRegisterInfo());
1160 }
1161 AP.OutStreamer->AddComment(OS.str());
1162 AP.OutStreamer->addBlankLine();
1163}
1164
1165/// emitDebugValueComment - This method handles the target-independent form
1166/// of DBG_VALUE, returning true if it was able to do so. A false return
1167/// means the target will need to handle MI in EmitInstruction.
1169 // This code handles only the 4-operand target-independent form.
1170 if (MI->isNonListDebugValue() && MI->getNumOperands() != 4)
1171 return false;
1172
1173 SmallString<128> Str;
1175 OS << "DEBUG_VALUE: ";
1176
1177 const DILocalVariable *V = MI->getDebugVariable();
1178 if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
1179 StringRef Name = SP->getName();
1180 if (!Name.empty())
1181 OS << Name << ":";
1182 }
1183 OS << V->getName();
1184 OS << " <- ";
1185
1186 const DIExpression *Expr = MI->getDebugExpression();
1187 // First convert this to a non-variadic expression if possible, to simplify
1188 // the output.
1189 if (auto NonVariadicExpr = DIExpression::convertToNonVariadicExpression(Expr))
1190 Expr = *NonVariadicExpr;
1191 // Then, output the possibly-simplified expression.
1192 if (Expr->getNumElements()) {
1193 OS << '[';
1194 ListSeparator LS;
1195 for (auto &Op : Expr->expr_ops()) {
1196 OS << LS << dwarf::OperationEncodingString(Op.getOp());
1197 for (unsigned I = 0; I < Op.getNumArgs(); ++I)
1198 OS << ' ' << Op.getArg(I);
1199 }
1200 OS << "] ";
1201 }
1202
1203 // Register or immediate value. Register 0 means undef.
1204 for (const MachineOperand &Op : MI->debug_operands()) {
1205 if (&Op != MI->debug_operands().begin())
1206 OS << ", ";
1207 switch (Op.getType()) {
1209 APFloat APF = APFloat(Op.getFPImm()->getValueAPF());
1210 Type *ImmTy = Op.getFPImm()->getType();
1211 if (ImmTy->isBFloatTy() || ImmTy->isHalfTy() || ImmTy->isFloatTy() ||
1212 ImmTy->isDoubleTy()) {
1213 OS << APF.convertToDouble();
1214 } else {
1215 // There is no good way to print long double. Convert a copy to
1216 // double. Ah well, it's only a comment.
1217 bool ignored;
1219 &ignored);
1220 OS << "(long double) " << APF.convertToDouble();
1221 }
1222 break;
1223 }
1225 OS << Op.getImm();
1226 break;
1227 }
1229 Op.getCImm()->getValue().print(OS, false /*isSigned*/);
1230 break;
1231 }
1233 OS << "!target-index(" << Op.getIndex() << "," << Op.getOffset() << ")";
1234 break;
1235 }
1238 Register Reg;
1239 std::optional<StackOffset> Offset;
1240 if (Op.isReg()) {
1241 Reg = Op.getReg();
1242 } else {
1243 const TargetFrameLowering *TFI =
1245 Offset = TFI->getFrameIndexReference(*AP.MF, Op.getIndex(), Reg);
1246 }
1247 if (!Reg) {
1248 // Suppress offset, it is not meaningful here.
1249 OS << "undef";
1250 break;
1251 }
1252 // The second operand is only an offset if it's an immediate.
1253 if (MI->isIndirectDebugValue())
1254 Offset = StackOffset::getFixed(MI->getDebugOffset().getImm());
1255 if (Offset)
1256 OS << '[';
1257 OS << printReg(Reg, AP.MF->getSubtarget().getRegisterInfo());
1258 if (Offset)
1259 OS << '+' << Offset->getFixed() << ']';
1260 break;
1261 }
1262 default:
1263 llvm_unreachable("Unknown operand type");
1264 }
1265 }
1266
1267 // NOTE: Want this comment at start of line, don't emit with AddComment.
1268 AP.OutStreamer->emitRawComment(OS.str());
1269 return true;
1270}
1271
1272/// This method handles the target-independent form of DBG_LABEL, returning
1273/// true if it was able to do so. A false return means the target will need
1274/// to handle MI in EmitInstruction.
1276 if (MI->getNumOperands() != 1)
1277 return false;
1278
1279 SmallString<128> Str;
1281 OS << "DEBUG_LABEL: ";
1282
1283 const DILabel *V = MI->getDebugLabel();
1284 if (auto *SP = dyn_cast<DISubprogram>(
1285 V->getScope()->getNonLexicalBlockFileScope())) {
1286 StringRef Name = SP->getName();
1287 if (!Name.empty())
1288 OS << Name << ":";
1289 }
1290 OS << V->getName();
1291
1292 // NOTE: Want this comment at start of line, don't emit with AddComment.
1293 AP.OutStreamer->emitRawComment(OS.str());
1294 return true;
1295}
1296
1299 // Ignore functions that won't get emitted.
1300 if (F.isDeclarationForLinker())
1301 return CFISection::None;
1302
1304 F.needsUnwindTableEntry())
1305 return CFISection::EH;
1306
1307 if (MAI->usesCFIWithoutEH() && F.hasUWTable())
1308 return CFISection::EH;
1309
1310 assert(MMI != nullptr && "Invalid machine module info");
1312 return CFISection::Debug;
1313
1314 return CFISection::None;
1315}
1316
1320}
1321
1324}
1325
1327 return MAI->usesCFIWithoutEH() && ModuleCFISection != CFISection::None;
1328}
1329
1331 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
1332 if (!usesCFIWithoutEH() &&
1333 ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
1334 ExceptionHandlingType != ExceptionHandling::ARM)
1335 return;
1336
1338 return;
1339
1340 // If there is no "real" instruction following this CFI instruction, skip
1341 // emitting it; it would be beyond the end of the function's FDE range.
1342 auto *MBB = MI.getParent();
1343 auto I = std::next(MI.getIterator());
1344 while (I != MBB->end() && I->isTransient())
1345 ++I;
1346 if (I == MBB->instr_end() &&
1348 return;
1349
1350 const std::vector<MCCFIInstruction> &Instrs = MF->getFrameInstructions();
1351 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
1352 const MCCFIInstruction &CFI = Instrs[CFIIndex];
1353 emitCFIInstruction(CFI);
1354}
1355
1357 // The operands are the MCSymbol and the frame offset of the allocation.
1358 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
1359 int FrameOffset = MI.getOperand(1).getImm();
1360
1361 // Emit a symbol assignment.
1362 OutStreamer->emitAssignment(FrameAllocSym,
1363 MCConstantExpr::create(FrameOffset, OutContext));
1364}
1365
1366/// Returns the BB metadata to be emitted in the SHT_LLVM_BB_ADDR_MAP section
1367/// for a given basic block. This can be used to capture more precise profile
1368/// information.
1373 MBB.isEHPad(), const_cast<MachineBasicBlock &>(MBB).canFallThrough(),
1374 !MBB.empty() && MBB.rbegin()->isIndirectBranch()}
1375 .encode();
1376}
1377
1379getBBAddrMapFeature(const MachineFunction &MF, int NumMBBSectionRanges) {
1380 return {PgoAnalysisMapFeatures.isSet(PGOMapFeaturesEnum::FuncEntryCount),
1381 PgoAnalysisMapFeatures.isSet(PGOMapFeaturesEnum::BBFreq),
1382 PgoAnalysisMapFeatures.isSet(PGOMapFeaturesEnum::BrProb),
1383 MF.hasBBSections() && NumMBBSectionRanges > 1};
1384}
1385
1387 MCSection *BBAddrMapSection =
1389 assert(BBAddrMapSection && ".llvm_bb_addr_map section is not initialized.");
1390
1391 const MCSymbol *FunctionSymbol = getFunctionBegin();
1392
1393 OutStreamer->pushSection();
1394 OutStreamer->switchSection(BBAddrMapSection);
1395 OutStreamer->AddComment("version");
1396 uint8_t BBAddrMapVersion = OutStreamer->getContext().getBBAddrMapVersion();
1397 OutStreamer->emitInt8(BBAddrMapVersion);
1398 OutStreamer->AddComment("feature");
1399 auto Features = getBBAddrMapFeature(MF, MBBSectionRanges.size());
1400 OutStreamer->emitInt8(Features.encode());
1401 // Emit BB Information for each basic block in the function.
1402 if (Features.MultiBBRange) {
1403 OutStreamer->AddComment("number of basic block ranges");
1404 OutStreamer->emitULEB128IntValue(MBBSectionRanges.size());
1405 }
1406 // Number of blocks in each MBB section.
1407 MapVector<unsigned, unsigned> MBBSectionNumBlocks;
1408 const MCSymbol *PrevMBBEndSymbol = nullptr;
1409 if (!Features.MultiBBRange) {
1410 OutStreamer->AddComment("function address");
1411 OutStreamer->emitSymbolValue(FunctionSymbol, getPointerSize());
1412 OutStreamer->AddComment("number of basic blocks");
1413 OutStreamer->emitULEB128IntValue(MF.size());
1414 PrevMBBEndSymbol = FunctionSymbol;
1415 } else {
1416 unsigned BBCount = 0;
1417 for (const MachineBasicBlock &MBB : MF) {
1418 BBCount++;
1419 if (MBB.isEndSection()) {
1420 // Store each section's basic block count when it ends.
1421 MBBSectionNumBlocks[MBB.getSectionIDNum()] = BBCount;
1422 // Reset the count for the next section.
1423 BBCount = 0;
1424 }
1425 }
1426 }
1427 // Emit the BB entry for each basic block in the function.
1428 for (const MachineBasicBlock &MBB : MF) {
1429 const MCSymbol *MBBSymbol =
1430 MBB.isEntryBlock() ? FunctionSymbol : MBB.getSymbol();
1431 bool IsBeginSection =
1432 Features.MultiBBRange && (MBB.isBeginSection() || MBB.isEntryBlock());
1433 if (IsBeginSection) {
1434 OutStreamer->AddComment("base address");
1435 OutStreamer->emitSymbolValue(MBBSymbol, getPointerSize());
1436 OutStreamer->AddComment("number of basic blocks");
1437 OutStreamer->emitULEB128IntValue(
1438 MBBSectionNumBlocks[MBB.getSectionIDNum()]);
1439 PrevMBBEndSymbol = MBBSymbol;
1440 }
1441 // TODO: Remove this check when version 1 is deprecated.
1442 if (BBAddrMapVersion > 1) {
1443 OutStreamer->AddComment("BB id");
1444 // Emit the BB ID for this basic block.
1445 // We only emit BaseID since CloneID is unset for
1446 // basic-block-sections=labels.
1447 // TODO: Emit the full BBID when labels and sections can be mixed
1448 // together.
1449 OutStreamer->emitULEB128IntValue(MBB.getBBID()->BaseID);
1450 }
1451 // Emit the basic block offset relative to the end of the previous block.
1452 // This is zero unless the block is padded due to alignment.
1453 emitLabelDifferenceAsULEB128(MBBSymbol, PrevMBBEndSymbol);
1454 // Emit the basic block size. When BBs have alignments, their size cannot
1455 // always be computed from their offsets.
1457 // Emit the Metadata.
1458 OutStreamer->emitULEB128IntValue(getBBAddrMapMetadata(MBB));
1459 PrevMBBEndSymbol = MBB.getEndSymbol();
1460 }
1461
1462 if (Features.hasPGOAnalysis()) {
1463 assert(BBAddrMapVersion >= 2 &&
1464 "PGOAnalysisMap only supports version 2 or later");
1465
1466 if (Features.FuncEntryCount) {
1467 OutStreamer->AddComment("function entry count");
1468 auto MaybeEntryCount = MF.getFunction().getEntryCount();
1469 OutStreamer->emitULEB128IntValue(
1470 MaybeEntryCount ? MaybeEntryCount->getCount() : 0);
1471 }
1472 const MachineBlockFrequencyInfo *MBFI =
1473 Features.BBFreq
1474 ? &getAnalysis<LazyMachineBlockFrequencyInfoPass>().getBFI()
1475 : nullptr;
1476 const MachineBranchProbabilityInfo *MBPI =
1477 Features.BrProb ? &getAnalysis<MachineBranchProbabilityInfo>()
1478 : nullptr;
1479
1480 if (Features.BBFreq || Features.BrProb) {
1481 for (const MachineBasicBlock &MBB : MF) {
1482 if (Features.BBFreq) {
1483 OutStreamer->AddComment("basic block frequency");
1484 OutStreamer->emitULEB128IntValue(
1485 MBFI->getBlockFreq(&MBB).getFrequency());
1486 }
1487 if (Features.BrProb) {
1488 unsigned SuccCount = MBB.succ_size();
1489 OutStreamer->AddComment("basic block successor count");
1490 OutStreamer->emitULEB128IntValue(SuccCount);
1491 for (const MachineBasicBlock *SuccMBB : MBB.successors()) {
1492 OutStreamer->AddComment("successor BB ID");
1493 OutStreamer->emitULEB128IntValue(SuccMBB->getBBID()->BaseID);
1494 OutStreamer->AddComment("successor branch probability");
1495 OutStreamer->emitULEB128IntValue(
1496 MBPI->getEdgeProbability(&MBB, SuccMBB).getNumerator());
1497 }
1498 }
1499 }
1500 }
1501 }
1502
1503 OutStreamer->popSection();
1504}
1505
1507 const MCSymbol *Symbol) {
1508 MCSection *Section =
1510 if (!Section)
1511 return;
1512
1513 OutStreamer->pushSection();
1514 OutStreamer->switchSection(Section);
1515
1517 OutStreamer->emitLabel(Loc);
1518 OutStreamer->emitAbsoluteSymbolDiff(Symbol, Loc, 4);
1519
1520 OutStreamer->popSection();
1521}
1522
1524 const Function &F = MF.getFunction();
1525 if (const MDNode *MD = F.getMetadata(LLVMContext::MD_kcfi_type))
1526 emitGlobalConstant(F.getParent()->getDataLayout(),
1527 mdconst::extract<ConstantInt>(MD->getOperand(0)));
1528}
1529
1531 if (PP) {
1532 auto GUID = MI.getOperand(0).getImm();
1533 auto Index = MI.getOperand(1).getImm();
1534 auto Type = MI.getOperand(2).getImm();
1535 auto Attr = MI.getOperand(3).getImm();
1536 DILocation *DebugLoc = MI.getDebugLoc();
1537 PP->emitPseudoProbe(GUID, Index, Type, Attr, DebugLoc);
1538 }
1539}
1540
1543 return;
1544
1545 MCSection *StackSizeSection =
1547 if (!StackSizeSection)
1548 return;
1549
1550 const MachineFrameInfo &FrameInfo = MF.getFrameInfo();
1551 // Don't emit functions with dynamic stack allocations.
1552 if (FrameInfo.hasVarSizedObjects())
1553 return;
1554
1555 OutStreamer->pushSection();
1556 OutStreamer->switchSection(StackSizeSection);
1557
1558 const MCSymbol *FunctionSymbol = getFunctionBegin();
1559 uint64_t StackSize =
1560 FrameInfo.getStackSize() + FrameInfo.getUnsafeStackSize();
1561 OutStreamer->emitSymbolValue(FunctionSymbol, TM.getProgramPointerSize());
1562 OutStreamer->emitULEB128IntValue(StackSize);
1563
1564 OutStreamer->popSection();
1565}
1566
1568 const std::string &OutputFilename = MF.getTarget().Options.StackUsageOutput;
1569
1570 // OutputFilename empty implies -fstack-usage is not passed.
1571 if (OutputFilename.empty())
1572 return;
1573
1574 const MachineFrameInfo &FrameInfo = MF.getFrameInfo();
1575 uint64_t StackSize =
1576 FrameInfo.getStackSize() + FrameInfo.getUnsafeStackSize();
1577
1578 if (StackUsageStream == nullptr) {
1579 std::error_code EC;
1580 StackUsageStream =
1581 std::make_unique<raw_fd_ostream>(OutputFilename, EC, sys::fs::OF_Text);
1582 if (EC) {
1583 errs() << "Could not open file: " << EC.message();
1584 return;
1585 }
1586 }
1587
1588 if (const DISubprogram *DSP = MF.getFunction().getSubprogram())
1589 *StackUsageStream << DSP->getFilename() << ':' << DSP->getLine();
1590 else
1591 *StackUsageStream << MF.getFunction().getParent()->getName();
1592
1593 *StackUsageStream << ':' << MF.getName() << '\t' << StackSize << '\t';
1594 if (FrameInfo.hasVarSizedObjects())
1595 *StackUsageStream << "dynamic\n";
1596 else
1597 *StackUsageStream << "static\n";
1598}
1599
1601 const MDNode &MD) {
1602 MCSymbol *S = MF.getContext().createTempSymbol("pcsection");
1603 OutStreamer->emitLabel(S);
1604 PCSectionsSymbols[&MD].emplace_back(S);
1605}
1606
1608 const Function &F = MF.getFunction();
1609 if (PCSectionsSymbols.empty() && !F.hasMetadata(LLVMContext::MD_pcsections))
1610 return;
1611
1613 const unsigned RelativeRelocSize =
1615 : 4;
1616
1617 // Switch to PCSection, short-circuiting the common case where the current
1618 // section is still valid (assume most MD_pcsections contain just 1 section).
1619 auto SwitchSection = [&, Prev = StringRef()](const StringRef &Sec) mutable {
1620 if (Sec == Prev)
1621 return;
1623 assert(S && "PC section is not initialized");
1624 OutStreamer->switchSection(S);
1625 Prev = Sec;
1626 };
1627 // Emit symbols into sections and data as specified in the pcsections MDNode.
1628 auto EmitForMD = [&](const MDNode &MD, ArrayRef<const MCSymbol *> Syms,
1629 bool Deltas) {
1630 // Expect the first operand to be a section name. After that, a tuple of
1631 // constants may appear, which will simply be emitted into the current
1632 // section (the user of MD_pcsections decides the format of encoded data).
1633 assert(isa<MDString>(MD.getOperand(0)) && "first operand not a string");
1634 bool ConstULEB128 = false;
1635 for (const MDOperand &MDO : MD.operands()) {
1636 if (auto *S = dyn_cast<MDString>(MDO)) {
1637 // Found string, start of new section!
1638 // Find options for this section "<section>!<opts>" - supported options:
1639 // C = Compress constant integers of size 2-8 bytes as ULEB128.
1640 const StringRef SecWithOpt = S->getString();
1641 const size_t OptStart = SecWithOpt.find('!'); // likely npos
1642 const StringRef Sec = SecWithOpt.substr(0, OptStart);
1643 const StringRef Opts = SecWithOpt.substr(OptStart); // likely empty
1644 ConstULEB128 = Opts.contains('C');
1645#ifndef NDEBUG
1646 for (char O : Opts)
1647 assert((O == '!' || O == 'C') && "Invalid !pcsections options");
1648#endif
1649 SwitchSection(Sec);
1650 const MCSymbol *Prev = Syms.front();
1651 for (const MCSymbol *Sym : Syms) {
1652 if (Sym == Prev || !Deltas) {
1653 // Use the entry itself as the base of the relative offset.
1654 MCSymbol *Base = MF.getContext().createTempSymbol("pcsection_base");
1655 OutStreamer->emitLabel(Base);
1656 // Emit relative relocation `addr - base`, which avoids a dynamic
1657 // relocation in the final binary. User will get the address with
1658 // `base + addr`.
1659 emitLabelDifference(Sym, Base, RelativeRelocSize);
1660 } else {
1661 // Emit delta between symbol and previous symbol.
1662 if (ConstULEB128)
1664 else
1665 emitLabelDifference(Sym, Prev, 4);
1666 }
1667 Prev = Sym;
1668 }
1669 } else {
1670 // Emit auxiliary data after PC.
1671 assert(isa<MDNode>(MDO) && "expecting either string or tuple");
1672 const auto *AuxMDs = cast<MDNode>(MDO);
1673 for (const MDOperand &AuxMDO : AuxMDs->operands()) {
1674 assert(isa<ConstantAsMetadata>(AuxMDO) && "expecting a constant");
1675 const Constant *C = cast<ConstantAsMetadata>(AuxMDO)->getValue();
1676 const DataLayout &DL = F.getParent()->getDataLayout();
1677 const uint64_t Size = DL.getTypeStoreSize(C->getType());
1678
1679 if (auto *CI = dyn_cast<ConstantInt>(C);
1680 CI && ConstULEB128 && Size > 1 && Size <= 8) {
1681 emitULEB128(CI->getZExtValue());
1682 } else {
1684 }
1685 }
1686 }
1687 }
1688 };
1689
1690 OutStreamer->pushSection();
1691 // Emit PCs for function start and function size.
1692 if (const MDNode *MD = F.getMetadata(LLVMContext::MD_pcsections))
1693 EmitForMD(*MD, {getFunctionBegin(), getFunctionEnd()}, true);
1694 // Emit PCs for instructions collected.
1695 for (const auto &MS : PCSectionsSymbols)
1696 EmitForMD(*MS.first, MS.second, false);
1697 OutStreamer->popSection();
1698 PCSectionsSymbols.clear();
1699}
1700
1701/// Returns true if function begin and end labels should be emitted.
1702static bool needFuncLabels(const MachineFunction &MF) {
1703 MachineModuleInfo &MMI = MF.getMMI();
1704 if (!MF.getLandingPads().empty() || MF.hasEHFunclets() ||
1705 MMI.hasDebugInfo() ||
1706 MF.getFunction().hasMetadata(LLVMContext::MD_pcsections))
1707 return true;
1708
1709 // We might emit an EH table that uses function begin and end labels even if
1710 // we don't have any landingpads.
1711 if (!MF.getFunction().hasPersonalityFn())
1712 return false;
1713 return !isNoOpWithoutInvoke(
1715}
1716
1717/// EmitFunctionBody - This method emits the body and trailer for a
1718/// function.
1720 emitFunctionHeader();
1721
1722 // Emit target-specific gunk before the function body.
1724
1725 if (isVerbose()) {
1726 // Get MachineDominatorTree or compute it on the fly if it's unavailable
1727 MDT = getAnalysisIfAvailable<MachineDominatorTree>();
1728 if (!MDT) {
1729 OwnedMDT = std::make_unique<MachineDominatorTree>();
1730 OwnedMDT->getBase().recalculate(*MF);
1731 MDT = OwnedMDT.get();
1732 }
1733
1734 // Get MachineLoopInfo or compute it on the fly if it's unavailable
1735 MLI = getAnalysisIfAvailable<MachineLoopInfo>();
1736 if (!MLI) {
1737 OwnedMLI = std::make_unique<MachineLoopInfo>();
1738 OwnedMLI->getBase().analyze(MDT->getBase());
1739 MLI = OwnedMLI.get();
1740 }
1741 }
1742
1743 // Print out code for the function.
1744 bool HasAnyRealCode = false;
1745 int NumInstsInFunction = 0;
1746 bool IsEHa = MMI->getModule()->getModuleFlag("eh-asynch");
1747
1748 bool CanDoExtraAnalysis = ORE->allowExtraAnalysis(DEBUG_TYPE);
1749 for (auto &MBB : *MF) {
1750 // Print a label for the basic block.
1752 DenseMap<StringRef, unsigned> MnemonicCounts;
1753 for (auto &MI : MBB) {
1754 // Print the assembly for the instruction.
1755 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
1756 !MI.isDebugInstr()) {
1757 HasAnyRealCode = true;
1758 ++NumInstsInFunction;
1759 }
1760
1761 // If there is a pre-instruction symbol, emit a label for it here.
1762 if (MCSymbol *S = MI.getPreInstrSymbol())
1763 OutStreamer->emitLabel(S);
1764
1765 if (MDNode *MD = MI.getPCSections())
1766 emitPCSectionsLabel(*MF, *MD);
1767
1768 for (const HandlerInfo &HI : Handlers) {
1769 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1770 HI.TimerGroupDescription, TimePassesIsEnabled);
1771 HI.Handler->beginInstruction(&MI);
1772 }
1773
1774 if (isVerbose())
1775 emitComments(MI, OutStreamer->getCommentOS());
1776
1777 switch (MI.getOpcode()) {
1778 case TargetOpcode::CFI_INSTRUCTION:
1780 break;
1781 case TargetOpcode::LOCAL_ESCAPE:
1783 break;
1784 case TargetOpcode::ANNOTATION_LABEL:
1785 case TargetOpcode::GC_LABEL:
1786 OutStreamer->emitLabel(MI.getOperand(0).getMCSymbol());
1787 break;
1788 case TargetOpcode::EH_LABEL:
1789 OutStreamer->emitLabel(MI.getOperand(0).getMCSymbol());
1790 // For AsynchEH, insert a Nop if followed by a trap inst
1791 // Or the exception won't be caught.
1792 // (see MCConstantExpr::create(1,..) in WinException.cpp)
1793 // Ignore SDiv/UDiv because a DIV with Const-0 divisor
1794 // must have being turned into an UndefValue.
1795 // Div with variable opnds won't be the first instruction in
1796 // an EH region as it must be led by at least a Load
1797 {
1798 auto MI2 = std::next(MI.getIterator());
1799 if (IsEHa && MI2 != MBB.end() &&
1800 (MI2->mayLoadOrStore() || MI2->mayRaiseFPException()))
1801 emitNops(1);
1802 }
1803 break;
1804 case TargetOpcode::INLINEASM:
1805 case TargetOpcode::INLINEASM_BR:
1806 emitInlineAsm(&MI);
1807 break;
1808 case TargetOpcode::DBG_VALUE:
1809 case TargetOpcode::DBG_VALUE_LIST:
1810 if (isVerbose()) {
1811 if (!emitDebugValueComment(&MI, *this))
1813 }
1814 break;
1815 case TargetOpcode::DBG_INSTR_REF:
1816 // This instruction reference will have been resolved to a machine
1817 // location, and a nearby DBG_VALUE created. We can safely ignore
1818 // the instruction reference.
1819 break;
1820 case TargetOpcode::DBG_PHI:
1821 // This instruction is only used to label a program point, it's purely
1822 // meta information.
1823 break;
1824 case TargetOpcode::DBG_LABEL:
1825 if (isVerbose()) {
1826 if (!emitDebugLabelComment(&MI, *this))
1828 }
1829 break;
1830 case TargetOpcode::IMPLICIT_DEF:
1831 if (isVerbose()) emitImplicitDef(&MI);
1832 break;
1833 case TargetOpcode::KILL:
1834 if (isVerbose()) emitKill(&MI, *this);
1835 break;
1836 case TargetOpcode::PSEUDO_PROBE:
1838 break;
1839 case TargetOpcode::ARITH_FENCE:
1840 if (isVerbose())
1841 OutStreamer->emitRawComment("ARITH_FENCE");
1842 break;
1843 case TargetOpcode::MEMBARRIER:
1844 OutStreamer->emitRawComment("MEMBARRIER");
1845 break;
1846 case TargetOpcode::JUMP_TABLE_DEBUG_INFO:
1847 // This instruction is only used to note jump table debug info, it's
1848 // purely meta information.
1849 break;
1850 default:
1852 if (CanDoExtraAnalysis) {
1853 MCInst MCI;
1854 MCI.setOpcode(MI.getOpcode());
1855 auto Name = OutStreamer->getMnemonic(MCI);
1856 auto I = MnemonicCounts.insert({Name, 0u});
1857 I.first->second++;
1858 }
1859 break;
1860 }
1861
1862 // If there is a post-instruction symbol, emit a label for it here.
1863 if (MCSymbol *S = MI.getPostInstrSymbol())
1864 OutStreamer->emitLabel(S);
1865
1866 for (const HandlerInfo &HI : Handlers) {
1867 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1868 HI.TimerGroupDescription, TimePassesIsEnabled);
1869 HI.Handler->endInstruction();
1870 }
1871 }
1872
1873 // We must emit temporary symbol for the end of this basic block, if either
1874 // we have BBLabels enabled or if this basic blocks marks the end of a
1875 // section.
1876 if (MF->hasBBLabels() || MF->getTarget().Options.BBAddrMap ||
1878 OutStreamer->emitLabel(MBB.getEndSymbol());
1879
1880 if (MBB.isEndSection()) {
1881 // The size directive for the section containing the entry block is
1882 // handled separately by the function section.
1883 if (!MBB.sameSection(&MF->front())) {
1885 // Emit the size directive for the basic block section.
1886 const MCExpr *SizeExp = MCBinaryExpr::createSub(
1888 MCSymbolRefExpr::create(CurrentSectionBeginSym, OutContext),
1889 OutContext);
1890 OutStreamer->emitELFSize(CurrentSectionBeginSym, SizeExp);
1891 }
1893 MBBSectionRange{CurrentSectionBeginSym, MBB.getEndSymbol()};
1894 }
1895 }
1897
1898 if (CanDoExtraAnalysis) {
1899 // Skip empty blocks.
1900 if (MBB.empty())
1901 continue;
1902
1904 MBB.begin()->getDebugLoc(), &MBB);
1905
1906 // Generate instruction mix remark. First, sort counts in descending order
1907 // by count and name.
1909 for (auto &KV : MnemonicCounts)
1910 MnemonicVec.emplace_back(KV.first, KV.second);
1911
1912 sort(MnemonicVec, [](const std::pair<StringRef, unsigned> &A,
1913 const std::pair<StringRef, unsigned> &B) {
1914 if (A.second > B.second)
1915 return true;
1916 if (A.second == B.second)
1917 return StringRef(A.first) < StringRef(B.first);
1918 return false;
1919 });
1920 R << "BasicBlock: " << ore::NV("BasicBlock", MBB.getName()) << "\n";
1921 for (auto &KV : MnemonicVec) {
1922 auto Name = (Twine("INST_") + getToken(KV.first.trim()).first).str();
1923 R << KV.first << ": " << ore::NV(Name, KV.second) << "\n";
1924 }
1925 ORE->emit(R);
1926 }
1927 }
1928
1929 EmittedInsts += NumInstsInFunction;
1930 MachineOptimizationRemarkAnalysis R(DEBUG_TYPE, "InstructionCount",
1932 &MF->front());
1933 R << ore::NV("NumInstructions", NumInstsInFunction)
1934 << " instructions in function";
1935 ORE->emit(R);
1936
1937 // If the function is empty and the object file uses .subsections_via_symbols,
1938 // then we need to emit *something* to the function body to prevent the
1939 // labels from collapsing together. Just emit a noop.
1940 // Similarly, don't emit empty functions on Windows either. It can lead to
1941 // duplicate entries (two functions with the same RVA) in the Guard CF Table
1942 // after linking, causing the kernel not to load the binary:
1943 // https://developercommunity.visualstudio.com/content/problem/45366/vc-linker-creates-invalid-dll-with-clang-cl.html
1944 // FIXME: Hide this behind some API in e.g. MCAsmInfo or MCTargetStreamer.
1945 const Triple &TT = TM.getTargetTriple();
1946 if (!HasAnyRealCode && (MAI->hasSubsectionsViaSymbols() ||
1947 (TT.isOSWindows() && TT.isOSBinFormatCOFF()))) {
1948 MCInst Noop = MF->getSubtarget().getInstrInfo()->getNop();
1949
1950 // Targets can opt-out of emitting the noop here by leaving the opcode
1951 // unspecified.
1952 if (Noop.getOpcode()) {
1953 OutStreamer->AddComment("avoids zero-length function");
1954 emitNops(1);
1955 }
1956 }
1957
1958 // Switch to the original section in case basic block sections was used.
1959 OutStreamer->switchSection(MF->getSection());
1960
1961 const Function &F = MF->getFunction();
1962 for (const auto &BB : F) {
1963 if (!BB.hasAddressTaken())
1964 continue;
1966 if (Sym->isDefined())
1967 continue;
1968 OutStreamer->AddComment("Address of block that was removed by CodeGen");
1969 OutStreamer->emitLabel(Sym);
1970 }
1971
1972 // Emit target-specific gunk after the function body.
1974
1975 // Even though wasm supports .type and .size in general, function symbols
1976 // are automatically sized.
1977 bool EmitFunctionSize = MAI->hasDotTypeDotSizeDirective() && !TT.isWasm();
1978
1979 if (needFuncLabels(*MF) || EmitFunctionSize) {
1980 // Create a symbol for the end of function.
1981 CurrentFnEnd = createTempSymbol("func_end");
1982 OutStreamer->emitLabel(CurrentFnEnd);
1983 }
1984
1985 // If the target wants a .size directive for the size of the function, emit
1986 // it.
1987 if (EmitFunctionSize) {
1988 // We can get the size as difference between the function label and the
1989 // temp label.
1990 const MCExpr *SizeExp = MCBinaryExpr::createSub(
1991 MCSymbolRefExpr::create(CurrentFnEnd, OutContext),
1993 OutStreamer->emitELFSize(CurrentFnSym, SizeExp);
1995 OutStreamer->emitELFSize(CurrentFnBeginLocal, SizeExp);
1996 }
1997
1998 // Call endBasicBlockSection on the last block now, if it wasn't already
1999 // called.
2000 if (!MF->back().isEndSection()) {
2001 for (const HandlerInfo &HI : Handlers) {
2002 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
2003 HI.TimerGroupDescription, TimePassesIsEnabled);
2004 HI.Handler->endBasicBlockSection(MF->back());
2005 }
2006 }
2007 for (const HandlerInfo &HI : Handlers) {
2008 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
2009 HI.TimerGroupDescription, TimePassesIsEnabled);
2010 HI.Handler->markFunctionEnd();
2011 }
2012
2014 MBBSectionRange{CurrentFnBegin, CurrentFnEnd};
2015
2016 // Print out jump tables referenced by the function.
2018
2019 // Emit post-function debug and/or EH information.
2020 for (const HandlerInfo &HI : Handlers) {
2021 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
2022 HI.TimerGroupDescription, TimePassesIsEnabled);
2023 HI.Handler->endFunction(MF);
2024 }
2025
2026 // Emit section containing BB address offsets and their metadata, when
2027 // BB labels are requested for this function. Skip empty functions.
2028 if (HasAnyRealCode) {
2031 else if (PgoAnalysisMapFeatures.getBits() != 0)
2033 SMLoc(), "pgo-analysis-map is enabled for function " + MF->getName() +
2034 " but it does not have labels");
2035 }
2036
2037 // Emit sections containing instruction and function PCs.
2039
2040 // Emit section containing stack size metadata.
2042
2043 // Emit .su file containing function stack size information.
2045
2047
2048 if (isVerbose())
2049 OutStreamer->getCommentOS() << "-- End function\n";
2050
2051 OutStreamer->addBlankLine();
2052}
2053
2054/// Compute the number of Global Variables that uses a Constant.
2055static unsigned getNumGlobalVariableUses(const Constant *C) {
2056 if (!C)
2057 return 0;
2058
2059 if (isa<GlobalVariable>(C))
2060 return 1;
2061
2062 unsigned NumUses = 0;
2063 for (const auto *CU : C->users())
2064 NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
2065
2066 return NumUses;
2067}
2068
2069/// Only consider global GOT equivalents if at least one user is a
2070/// cstexpr inside an initializer of another global variables. Also, don't
2071/// handle cstexpr inside instructions. During global variable emission,
2072/// candidates are skipped and are emitted later in case at least one cstexpr
2073/// isn't replaced by a PC relative GOT entry access.
2075 unsigned &NumGOTEquivUsers) {
2076 // Global GOT equivalents are unnamed private globals with a constant
2077 // pointer initializer to another global symbol. They must point to a
2078 // GlobalVariable or Function, i.e., as GlobalValue.
2079 if (!GV->hasGlobalUnnamedAddr() || !GV->hasInitializer() ||
2080 !GV->isConstant() || !GV->isDiscardableIfUnused() ||
2081 !isa<GlobalValue>(GV->getOperand(0)))
2082 return false;
2083
2084 // To be a got equivalent, at least one of its users need to be a constant
2085 // expression used by another global variable.
2086 for (const auto *U : GV->users())
2087 NumGOTEquivUsers += getNumGlobalVariableUses(dyn_cast<Constant>(U));
2088
2089 return NumGOTEquivUsers > 0;
2090}
2091
2092/// Unnamed constant global variables solely contaning a pointer to
2093/// another globals variable is equivalent to a GOT table entry; it contains the
2094/// the address of another symbol. Optimize it and replace accesses to these
2095/// "GOT equivalents" by using the GOT entry for the final global instead.
2096/// Compute GOT equivalent candidates among all global variables to avoid
2097/// emitting them if possible later on, after it use is replaced by a GOT entry
2098/// access.
2100 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
2101 return;
2102
2103 for (const auto &G : M.globals()) {
2104 unsigned NumGOTEquivUsers = 0;
2105 if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
2106 continue;
2107
2108 const MCSymbol *GOTEquivSym = getSymbol(&G);
2109 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
2110 }
2111}
2112
2113/// Constant expressions using GOT equivalent globals may not be eligible
2114/// for PC relative GOT entry conversion, in such cases we need to emit such
2115/// globals we previously omitted in EmitGlobalVariable.
2117 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
2118 return;
2119
2121 for (auto &I : GlobalGOTEquivs) {
2122 const GlobalVariable *GV = I.second.first;
2123 unsigned Cnt = I.second.second;
2124 if (Cnt)
2125 FailedCandidates.push_back(GV);
2126 }
2127 GlobalGOTEquivs.clear();
2128
2129 for (const auto *GV : FailedCandidates)
2131}
2132
2133void AsmPrinter::emitGlobalAlias(const Module &M, const GlobalAlias &GA) {
2134 MCSymbol *Name = getSymbol(&GA);
2135 bool IsFunction = GA.getValueType()->isFunctionTy();
2136 // Treat bitcasts of functions as functions also. This is important at least
2137 // on WebAssembly where object and function addresses can't alias each other.
2138 if (!IsFunction)
2139 IsFunction = isa<Function>(GA.getAliasee()->stripPointerCasts());
2140
2141 // AIX's assembly directive `.set` is not usable for aliasing purpose,
2142 // so AIX has to use the extra-label-at-definition strategy. At this
2143 // point, all the extra label is emitted, we just have to emit linkage for
2144 // those labels.
2147 "Visibility should be handled with emitLinkage() on AIX.");
2148
2149 // Linkage for alias of global variable has been emitted.
2150 if (isa<GlobalVariable>(GA.getAliaseeObject()))
2151 return;
2152
2153 emitLinkage(&GA, Name);
2154 // If it's a function, also emit linkage for aliases of function entry
2155 // point.
2156 if (IsFunction)
2157 emitLinkage(&GA,
2158 getObjFileLowering().getFunctionEntryPointSymbol(&GA, TM));
2159 return;
2160 }
2161
2163 OutStreamer->emitSymbolAttribute(Name, MCSA_Global);
2164 else if (GA.hasWeakLinkage() || GA.hasLinkOnceLinkage())
2165 OutStreamer->emitSymbolAttribute(Name, MCSA_WeakReference);
2166 else
2167 assert(GA.hasLocalLinkage() && "Invalid alias linkage");
2168
2169 // Set the symbol type to function if the alias has a function type.
2170 // This affects codegen when the aliasee is not a function.
2171 if (IsFunction) {
2172 OutStreamer->emitSymbolAttribute(Name, MCSA_ELF_TypeFunction);
2174 OutStreamer->beginCOFFSymbolDef(Name);
2175 OutStreamer->emitCOFFSymbolStorageClass(
2180 OutStreamer->endCOFFSymbolDef();
2181 }
2182 }
2183
2185
2186 const MCExpr *Expr = lowerConstant(GA.getAliasee());
2187
2188 if (MAI->hasAltEntry() && isa<MCBinaryExpr>(Expr))
2189 OutStreamer->emitSymbolAttribute(Name, MCSA_AltEntry);
2190
2191 // Emit the directives as assignments aka .set:
2192 OutStreamer->emitAssignment(Name, Expr);
2193 MCSymbol *LocalAlias = getSymbolPreferLocal(GA);
2194 if (LocalAlias != Name)
2195 OutStreamer->emitAssignment(LocalAlias, Expr);
2196
2197 // If the aliasee does not correspond to a symbol in the output, i.e. the
2198 // alias is not of an object or the aliased object is private, then set the
2199 // size of the alias symbol from the type of the alias. We don't do this in
2200 // other situations as the alias and aliasee having differing types but same
2201 // size may be intentional.
2202 const GlobalObject *BaseObject = GA.getAliaseeObject();
2204 (!BaseObject || BaseObject->hasPrivateLinkage())) {
2205 const DataLayout &DL = M.getDataLayout();
2206 uint64_t Size = DL.getTypeAllocSize(GA.getValueType());
2208 }
2209}
2210
2211void AsmPrinter::emitGlobalIFunc(Module &M, const GlobalIFunc &GI) {
2213 "IFunc is not supported on AIX.");
2214
2215 auto EmitLinkage = [&](MCSymbol *Sym) {
2217 OutStreamer->emitSymbolAttribute(Sym, MCSA_Global);
2218 else if (GI.hasWeakLinkage() || GI.hasLinkOnceLinkage())
2219 OutStreamer->emitSymbolAttribute(Sym, MCSA_WeakReference);
2220 else
2221 assert(GI.hasLocalLinkage() && "Invalid ifunc linkage");
2222 };
2223
2225 MCSymbol *Name = getSymbol(&GI);
2226 EmitLinkage(Name);
2227 OutStreamer->emitSymbolAttribute(Name, MCSA_ELF_TypeIndFunction);
2229
2230 // Emit the directives as assignments aka .set:
2231 const MCExpr *Expr = lowerConstant(GI.getResolver());
2232 OutStreamer->emitAssignment(Name, Expr);
2233 MCSymbol *LocalAlias = getSymbolPreferLocal(GI);
2234 if (LocalAlias != Name)
2235 OutStreamer->emitAssignment(LocalAlias, Expr);
2236
2237 return;
2238 }
2239
2241 llvm::report_fatal_error("IFuncs are not supported on this platform");
2242
2243 // On Darwin platforms, emit a manually-constructed .symbol_resolver that
2244 // implements the symbol resolution duties of the IFunc.
2245 //
2246 // Normally, this would be handled by linker magic, but unfortunately there
2247 // are a few limitations in ld64 and ld-prime's implementation of
2248 // .symbol_resolver that mean we can't always use them:
2249 //
2250 // * resolvers cannot be the target of an alias
2251 // * resolvers cannot have private linkage
2252 // * resolvers cannot have linkonce linkage
2253 // * resolvers cannot appear in executables
2254 // * resolvers cannot appear in bundles
2255 //
2256 // This works around that by emitting a close approximation of what the
2257 // linker would have done.
2258
2259 MCSymbol *LazyPointer =
2260 GetExternalSymbolSymbol(GI.getName() + ".lazy_pointer");
2261 MCSymbol *StubHelper = GetExternalSymbolSymbol(GI.getName() + ".stub_helper");
2262
2264
2265 const DataLayout &DL = M.getDataLayout();
2266 emitAlignment(Align(DL.getPointerSize()));
2267 OutStreamer->emitLabel(LazyPointer);
2268 emitVisibility(LazyPointer, GI.getVisibility());
2269 OutStreamer->emitValue(MCSymbolRefExpr::create(StubHelper, OutContext), 8);
2270
2272
2273 const TargetSubtargetInfo *STI =
2275 const TargetLowering *TLI = STI->getTargetLowering();
2276 Align TextAlign(TLI->getMinFunctionAlignment());
2277
2278 MCSymbol *Stub = getSymbol(&GI);
2279 EmitLinkage(Stub);
2280 OutStreamer->emitCodeAlignment(TextAlign, getIFuncMCSubtargetInfo());
2281 OutStreamer->emitLabel(Stub);
2282 emitVisibility(Stub, GI.getVisibility());
2283 emitMachOIFuncStubBody(M, GI, LazyPointer);
2284
2285 OutStreamer->emitCodeAlignment(TextAlign, getIFuncMCSubtargetInfo());
2286 OutStreamer->emitLabel(StubHelper);
2287 emitVisibility(StubHelper, GI.getVisibility());
2288 emitMachOIFuncStubHelperBody(M, GI, LazyPointer);
2289}
2290
2292 if (!RS.needsSection())
2293 return;
2294
2295 remarks::RemarkSerializer &RemarkSerializer = RS.getSerializer();
2296
2297 std::optional<SmallString<128>> Filename;
2298 if (std::optional<StringRef> FilenameRef = RS.getFilename()) {
2299 Filename = *FilenameRef;
2300 sys::fs::make_absolute(*Filename);
2301 assert(!Filename->empty() && "The filename can't be empty.");
2302 }
2303
2304 std::string Buf;
2306 std::unique_ptr<remarks::MetaSerializer> MetaSerializer =
2307 Filename ? RemarkSerializer.metaSerializer(OS, Filename->str())
2308 : RemarkSerializer.metaSerializer(OS);
2309 MetaSerializer->emit();
2310
2311 // Switch to the remarks section.
2312 MCSection *RemarksSection =
2314 OutStreamer->switchSection(RemarksSection);
2315
2316 OutStreamer->emitBinaryData(OS.str());
2317}
2318
2320 // Set the MachineFunction to nullptr so that we can catch attempted
2321 // accesses to MF specific features at the module level and so that
2322 // we can conditionalize accesses based on whether or not it is nullptr.
2323 MF = nullptr;
2324
2325 // Gather all GOT equivalent globals in the module. We really need two
2326 // passes over the globals: one to compute and another to avoid its emission
2327 // in EmitGlobalVariable, otherwise we would not be able to handle cases
2328 // where the got equivalent shows up before its use.
2330
2331 // Emit global variables.
2332 for (const auto &G : M.globals())
2334
2335 // Emit remaining GOT equivalent globals.
2337
2339
2340 // Emit linkage(XCOFF) and visibility info for declarations
2341 for (const Function &F : M) {
2342 if (!F.isDeclarationForLinker())
2343 continue;
2344
2345 MCSymbol *Name = getSymbol(&F);
2346 // Function getSymbol gives us the function descriptor symbol for XCOFF.
2347
2349 GlobalValue::VisibilityTypes V = F.getVisibility();
2351 continue;
2352
2353 emitVisibility(Name, V, false);
2354 continue;
2355 }
2356
2357 if (F.isIntrinsic())
2358 continue;
2359
2360 // Handle the XCOFF case.
2361 // Variable `Name` is the function descriptor symbol (see above). Get the
2362 // function entry point symbol.
2363 MCSymbol *FnEntryPointSym = TLOF.getFunctionEntryPointSymbol(&F, TM);
2364 // Emit linkage for the function entry point.
2365 emitLinkage(&F, FnEntryPointSym);
2366
2367 // Emit linkage for the function descriptor.
2368 emitLinkage(&F, Name);
2369 }
2370
2371 // Emit the remarks section contents.
2372 // FIXME: Figure out when is the safest time to emit this section. It should
2373 // not come after debug info.
2374 if (remarks::RemarkStreamer *RS = M.getContext().getMainRemarkStreamer())
2375 emitRemarksSection(*RS);
2376
2378
2381
2382 // Output stubs for external and common global variables.
2384 if (!Stubs.empty()) {
2385 OutStreamer->switchSection(TLOF.getDataSection());
2386 const DataLayout &DL = M.getDataLayout();
2387
2388 emitAlignment(Align(DL.getPointerSize()));
2389 for (const auto &Stub : Stubs) {
2390 OutStreamer->emitLabel(Stub.first);
2391 OutStreamer->emitSymbolValue(Stub.second.getPointer(),
2392 DL.getPointerSize());
2393 }
2394 }
2395 }
2396
2398 MachineModuleInfoCOFF &MMICOFF =
2400
2401 // Output stubs for external and common global variables.
2403 if (!Stubs.empty()) {
2404 const DataLayout &DL = M.getDataLayout();
2405
2406 for (const auto &Stub : Stubs) {
2408 SectionName += Stub.first->getName();
2409 OutStreamer->switchSection(OutContext.getCOFFSection(
2413 SectionKind::getReadOnly(), Stub.first->getName(),
2415 emitAlignment(Align(DL.getPointerSize()));
2416 OutStreamer->emitSymbolAttribute(Stub.first, MCSA_Global);
2417 OutStreamer->emitLabel(Stub.first);
2418 OutStreamer->emitSymbolValue(Stub.second.getPointer(),
2419 DL.getPointerSize());
2420 }
2421 }
2422 }
2423
2424 // This needs to happen before emitting debug information since that can end
2425 // arbitrary sections.
2426 if (auto *TS = OutStreamer->getTargetStreamer())
2427 TS->emitConstantPools();
2428
2429 // Emit Stack maps before any debug info. Mach-O requires that no data or
2430 // text sections come after debug info has been emitted. This matters for
2431 // stack maps as they are arbitrary data, and may even have a custom format
2432 // through user plugins.
2433 emitStackMaps();
2434
2435 // Print aliases in topological order, that is, for each alias a = b,
2436 // b must be printed before a.
2437 // This is because on some targets (e.g. PowerPC) linker expects aliases in
2438 // such an order to generate correct TOC information.
2441 for (const auto &Alias : M.aliases()) {
2442 if (Alias.hasAvailableExternallyLinkage())
2443 continue;
2444 for (const GlobalAlias *Cur = &Alias; Cur;
2445 Cur = dyn_cast<GlobalAlias>(Cur->getAliasee())) {
2446 if (!AliasVisited.insert(Cur).second)
2447 break;
2448 AliasStack.push_back(Cur);
2449 }
2450 for (const GlobalAlias *AncestorAlias : llvm::reverse(AliasStack))
2451 emitGlobalAlias(M, *AncestorAlias);
2452 AliasStack.clear();
2453 }
2454
2455 // IFuncs must come before deubginfo in case the backend decides to emit them
2456 // as actual functions, since on Mach-O targets, we cannot create regular
2457 // sections after DWARF.
2458 for (const auto &IFunc : M.ifuncs())
2459 emitGlobalIFunc(M, IFunc);
2460
2461 // Finalize debug and EH information.
2462 for (const HandlerInfo &HI : Handlers) {
2463 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
2464 HI.TimerGroupDescription, TimePassesIsEnabled);
2465 HI.Handler->endModule();
2466 }
2467
2468 // This deletes all the ephemeral handlers that AsmPrinter added, while
2469 // keeping all the user-added handlers alive until the AsmPrinter is
2470 // destroyed.
2471 Handlers.erase(Handlers.begin() + NumUserHandlers, Handlers.end());
2472 DD = nullptr;
2473
2474 // If the target wants to know about weak references, print them all.
2475 if (MAI->getWeakRefDirective()) {
2476 // FIXME: This is not lazy, it would be nice to only print weak references
2477 // to stuff that is actually used. Note that doing so would require targets
2478 // to notice uses in operands (due to constant exprs etc). This should
2479 // happen with the MC stuff eventually.
2480
2481 // Print out module-level global objects here.
2482 for (const auto &GO : M.global_objects()) {
2483 if (!GO.hasExternalWeakLinkage())
2484 continue;
2485 OutStreamer->emitSymbolAttribute(getSymbol(&GO), MCSA_WeakReference);
2486 }
2488 auto SymbolName = "swift_async_extendedFramePointerFlags";
2489 auto Global = M.getGlobalVariable(SymbolName);
2490 if (!Global) {
2491 auto Int8PtrTy = PointerType::getUnqual(M.getContext());
2492 Global = new GlobalVariable(M, Int8PtrTy, false,
2494 SymbolName);
2495 OutStreamer->emitSymbolAttribute(getSymbol(Global), MCSA_WeakReference);
2496 }
2497 }
2498 }
2499
2500 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
2501 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
2502 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
2503 if (GCMetadataPrinter *MP = getOrCreateGCPrinter(**--I))
2504 MP->finishAssembly(M, *MI, *this);
2505
2506 // Emit llvm.ident metadata in an '.ident' directive.
2507 emitModuleIdents(M);
2508
2509 // Emit bytes for llvm.commandline metadata.
2510 // The command line metadata is emitted earlier on XCOFF.
2512 emitModuleCommandLines(M);
2513
2514 // Emit .note.GNU-split-stack and .note.GNU-no-split-stack sections if
2515 // split-stack is used.
2516 if (TM.getTargetTriple().isOSBinFormatELF() && HasSplitStack) {
2517 OutStreamer->switchSection(OutContext.getELFSection(".note.GNU-split-stack",
2518 ELF::SHT_PROGBITS, 0));
2519 if (HasNoSplitStack)
2520 OutStreamer->switchSection(OutContext.getELFSection(
2521 ".note.GNU-no-split-stack", ELF::SHT_PROGBITS, 0));
2522 }
2523
2524 // If we don't have any trampolines, then we don't require stack memory
2525 // to be executable. Some targets have a directive to declare this.
2526 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
2527 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
2529 OutStreamer->switchSection(S);
2530
2531 if (TM.Options.EmitAddrsig) {
2532 // Emit address-significance attributes for all globals.
2533 OutStreamer->emitAddrsig();
2534 for (const GlobalValue &GV : M.global_values()) {
2535 if (!GV.use_empty() && !GV.isThreadLocal() &&
2536 !GV.hasDLLImportStorageClass() &&
2537 !GV.getName().starts_with("llvm.") &&
2538 !GV.hasAtLeastLocalUnnamedAddr())
2539 OutStreamer->emitAddrsigSym(getSymbol(&GV));
2540 }
2541 }
2542
2543 // Emit symbol partition specifications (ELF only).
2545 unsigned UniqueID = 0;
2546 for (const GlobalValue &GV : M.global_values()) {
2547 if (!GV.hasPartition() || GV.isDeclarationForLinker() ||
2548 GV.getVisibility() != GlobalValue::DefaultVisibility)
2549 continue;
2550
2551 OutStreamer->switchSection(
2552 OutContext.getELFSection(".llvm_sympart", ELF::SHT_LLVM_SYMPART, 0, 0,
2553 "", false, ++UniqueID, nullptr));
2554 OutStreamer->emitBytes(GV.getPartition());
2555 OutStreamer->emitZeros(1);
2556 OutStreamer->emitValue(
2559 }
2560 }
2561
2562 // Allow the target to emit any magic that it wants at the end of the file,
2563 // after everything else has gone out.
2565
2566 MMI = nullptr;
2567 AddrLabelSymbols = nullptr;
2568
2569 OutStreamer->finish();
2570 OutStreamer->reset();
2571 OwnedMLI.reset();
2572 OwnedMDT.reset();
2573
2574 return false;
2575}
2576
2578 auto Res = MBBSectionExceptionSyms.try_emplace(MBB.getSectionIDNum());
2579 if (Res.second)
2580 Res.first->second = createTempSymbol("exception");
2581 return Res.first->second;
2582}
2583
2585 this->MF = &MF;
2586 const Function &F = MF.getFunction();
2587
2588 // Record that there are split-stack functions, so we will emit a special
2589 // section to tell the linker.
2590 if (MF.shouldSplitStack()) {
2591 HasSplitStack = true;
2592
2594 HasNoSplitStack = true;
2595 } else
2596 HasNoSplitStack = true;
2597
2598 // Get the function symbol.
2599 if (!MAI->needsFunctionDescriptors()) {
2601 } else {
2603 "Only AIX uses the function descriptor hooks.");
2604 // AIX is unique here in that the name of the symbol emitted for the
2605 // function body does not have the same name as the source function's
2606 // C-linkage name.
2607 assert(CurrentFnDescSym && "The function descriptor symbol needs to be"
2608 " initalized first.");
2609
2610 // Get the function entry point symbol.
2612 }
2613
2615 CurrentFnBegin = nullptr;
2616 CurrentFnBeginLocal = nullptr;
2617 CurrentSectionBeginSym = nullptr;
2618 MBBSectionRanges.clear();
2619 MBBSectionExceptionSyms.clear();
2620 bool NeedsLocalForSize = MAI->needsLocalForSize();
2621 if (F.hasFnAttribute("patchable-function-entry") ||
2622 F.hasFnAttribute("function-instrument") ||
2623 F.hasFnAttribute("xray-instruction-threshold") || needFuncLabels(MF) ||
2624 NeedsLocalForSize || MF.getTarget().Options.EmitStackSizeSection ||
2626 CurrentFnBegin = createTempSymbol("func_begin");
2627 if (NeedsLocalForSize)
2629 }
2630
2631 ORE = &getAnalysis<MachineOptimizationRemarkEmitterPass>().getORE();
2632}
2633
2634namespace {
2635
2636// Keep track the alignment, constpool entries per Section.
2637 struct SectionCPs {
2638 MCSection *S;
2639 Align Alignment;
2641
2642 SectionCPs(MCSection *s, Align a) : S(s), Alignment(a) {}
2643 };
2644
2645} // end anonymous namespace
2646
2647/// EmitConstantPool - Print to the current output stream assembly
2648/// representations of the constants in the constant pool MCP. This is
2649/// used to print out constants which have been "spilled to memory" by
2650/// the code generator.
2652 const MachineConstantPool *MCP = MF->getConstantPool();
2653 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
2654 if (CP.empty()) return;
2655
2656 // Calculate sections for constant pool entries. We collect entries to go into
2657 // the same section together to reduce amount of section switch statements.
2658 SmallVector<SectionCPs, 4> CPSections;
2659 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
2660 const MachineConstantPoolEntry &CPE = CP[i];
2661 Align Alignment = CPE.getAlign();
2662
2664
2665 const Constant *C = nullptr;
2666 if (!CPE.isMachineConstantPoolEntry())
2667 C = CPE.Val.ConstVal;
2668
2670 getDataLayout(), Kind, C, Alignment);
2671
2672 // The number of sections are small, just do a linear search from the
2673 // last section to the first.
2674 bool Found = false;
2675 unsigned SecIdx = CPSections.size();
2676 while (SecIdx != 0) {
2677 if (CPSections[--SecIdx].S == S) {
2678 Found = true;
2679 break;
2680 }
2681 }
2682 if (!Found) {
2683 SecIdx = CPSections.size();
2684 CPSections.push_back(SectionCPs(S, Alignment));
2685 }
2686
2687 if (Alignment > CPSections[SecIdx].Alignment)
2688 CPSections[SecIdx].Alignment = Alignment;
2689 CPSections[SecIdx].CPEs.push_back(i);
2690 }
2691
2692 // Now print stuff into the calculated sections.
2693 const MCSection *CurSection = nullptr;
2694 unsigned Offset = 0;
2695 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
2696 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
2697 unsigned CPI = CPSections[i].CPEs[j];
2698 MCSymbol *Sym = GetCPISymbol(CPI);
2699 if (!Sym->isUndefined())
2700 continue;
2701
2702 if (CurSection != CPSections[i].S) {
2703 OutStreamer->switchSection(CPSections[i].S);
2704 emitAlignment(Align(CPSections[i].Alignment));
2705 CurSection = CPSections[i].S;
2706 Offset = 0;
2707 }
2708
2709 MachineConstantPoolEntry CPE = CP[CPI];
2710
2711 // Emit inter-object padding for alignment.
2712 unsigned NewOffset = alignTo(Offset, CPE.getAlign());
2713 OutStreamer->emitZeros(NewOffset - Offset);
2714
2715 Offset = NewOffset + CPE.getSizeInBytes(getDataLayout());
2716
2717 OutStreamer->emitLabel(Sym);
2720 else
2722 }
2723 }
2724}
2725
2726// Print assembly representations of the jump tables used by the current
2727// function.
2729 const DataLayout &DL = MF->getDataLayout();
2730 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
2731 if (!MJTI) return;
2732 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
2733 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
2734 if (JT.empty()) return;
2735
2736 // Pick the directive to use to print the jump table entries, and switch to
2737 // the appropriate section.
2738 const Function &F = MF->getFunction();
2740 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
2743 F);
2744 if (JTInDiffSection) {
2745 // Drop it in the readonly section.
2746 MCSection *ReadOnlySection = TLOF.getSectionForJumpTable(F, TM);
2747 OutStreamer->switchSection(ReadOnlySection);
2748 }
2749
2751
2752 // Jump tables in code sections are marked with a data_region directive
2753 // where that's supported.
2754 if (!JTInDiffSection)
2755 OutStreamer->emitDataRegion(MCDR_DataRegionJT32);
2756
2757 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
2758 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
2759
2760 // If this jump table was deleted, ignore it.
2761 if (JTBBs.empty()) continue;
2762
2763 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
2764 /// emit a .set directive for each unique entry.
2770 for (const MachineBasicBlock *MBB : JTBBs) {
2771 if (!EmittedSets.insert(MBB).second)
2772 continue;
2773
2774 // .set LJTSet, LBB32-base
2775 const MCExpr *LHS =
2777 OutStreamer->emitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
2779 OutContext));
2780 }
2781 }
2782
2783 // On some targets (e.g. Darwin) we want to emit two consecutive labels
2784 // before each jump table. The first label is never referenced, but tells
2785 // the assembler and linker the extents of the jump table object. The
2786 // second label is actually referenced by the code.
2787 if (JTInDiffSection && DL.hasLinkerPrivateGlobalPrefix())
2788 // FIXME: This doesn't have to have any specific name, just any randomly
2789 // named and numbered local label started with 'l' would work. Simplify
2790 // GetJTISymbol.
2791 OutStreamer->emitLabel(GetJTISymbol(JTI, true));
2792
2793 MCSymbol* JTISymbol = GetJTISymbol(JTI);
2794 OutStreamer->emitLabel(JTISymbol);
2795
2796 for (const MachineBasicBlock *MBB : JTBBs)
2797 emitJumpTableEntry(MJTI, MBB, JTI);
2798 }
2799 if (!JTInDiffSection)
2800 OutStreamer->emitDataRegion(MCDR_DataRegionEnd);
2801}
2802
2803/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
2804/// current stream.
2805void AsmPrinter::emitJumpTableEntry(const MachineJumpTableInfo *MJTI,
2806 const MachineBasicBlock *MBB,
2807 unsigned UID) const {
2808 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
2809 const MCExpr *Value = nullptr;
2810 switch (MJTI->getEntryKind()) {
2812 llvm_unreachable("Cannot emit EK_Inline jump table entry");
2815 MJTI, MBB, UID, OutContext);
2816 break;
2818 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
2819 // .word LBB123
2821 break;
2823 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
2824 // with a relocation as gp-relative, e.g.:
2825 // .gprel32 LBB123
2826 MCSymbol *MBBSym = MBB->getSymbol();
2827 OutStreamer->emitGPRel32Value(MCSymbolRefExpr::create(MBBSym, OutContext));
2828 return;
2829 }
2830
2832 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
2833 // with a relocation as gp-relative, e.g.:
2834 // .gpdword LBB123
2835 MCSymbol *MBBSym = MBB->getSymbol();
2836 OutStreamer->emitGPRel64Value(MCSymbolRefExpr::create(MBBSym, OutContext));
2837 return;
2838 }
2839
2842 // Each entry is the address of the block minus the address of the jump
2843 // table. This is used for PIC jump tables where gprel32 is not supported.
2844 // e.g.:
2845 // .word LBB123 - LJTI1_2
2846 // If the .set directive avoids relocations, this is emitted as:
2847 // .set L4_5_set_123, LBB123 - LJTI1_2
2848 // .word L4_5_set_123
2852 OutContext);
2853 break;
2854 }
2859 break;
2860 }
2861 }
2862
2863 assert(Value && "Unknown entry kind!");
2864
2865 unsigned EntrySize = MJTI->getEntrySize(getDataLayout());
2866 OutStreamer->emitValue(Value, EntrySize);
2867}
2868
2869/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
2870/// special global used by LLVM. If so, emit it and return true, otherwise
2871/// do nothing and return false.
2873 if (GV->getName() == "llvm.used") {
2874 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
2875 emitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
2876 return true;
2877 }
2878
2879 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
2880 if (GV->getSection() == "llvm.metadata" ||
2882 return true;
2883
2884 if (GV->getName() == "llvm.arm64ec.symbolmap") {
2885 // For ARM64EC, print the table that maps between symbols and the
2886 // corresponding thunks to translate between x64 and AArch64 code.
2887 // This table is generated by AArch64Arm64ECCallLowering.
2888 OutStreamer->switchSection(OutContext.getCOFFSection(
2890 auto *Arr = cast<ConstantArray>(GV->getInitializer());
2891 for (auto &U : Arr->operands()) {
2892 auto *C = cast<Constant>(U);
2893 auto *Src = cast<Function>(C->getOperand(0)->stripPointerCasts());
2894 auto *Dst = cast<Function>(C->getOperand(1)->stripPointerCasts());
2895 int Kind = cast<ConstantInt>(C->getOperand(2))->getZExtValue();
2896
2897 if (Src->hasDLLImportStorageClass()) {
2898 // For now, we assume dllimport functions aren't directly called.
2899 // (We might change this later to match MSVC.)
2900 OutStreamer->emitCOFFSymbolIndex(
2901 OutContext.getOrCreateSymbol("__imp_" + Src->getName()));
2902 OutStreamer->emitCOFFSymbolIndex(getSymbol(Dst));
2903 OutStreamer->emitInt32(Kind);
2904 } else {
2905 // FIXME: For non-dllimport functions, MSVC emits the same entry
2906 // twice, for reasons I don't understand. I have to assume the linker
2907 // ignores the redundant entry; there aren't any reasonable semantics
2908 // to attach to it.
2909 OutStreamer->emitCOFFSymbolIndex(getSymbol(Src));
2910 OutStreamer->emitCOFFSymbolIndex(getSymbol(Dst));
2911 OutStreamer->emitInt32(Kind);
2912 }
2913 }
2914 return true;
2915 }
2916
2917 if (!GV->hasAppendingLinkage()) return false;
2918
2919 assert(GV->hasInitializer() && "Not a special LLVM global!");
2920
2921 if (GV->getName() == "llvm.global_ctors") {
2923 /* isCtor */ true);
2924
2925 return true;
2926 }
2927
2928 if (GV->getName() == "llvm.global_dtors") {
2930 /* isCtor */ false);
2931
2932 return true;
2933 }
2934
2935 report_fatal_error("unknown special variable with appending linkage");
2936}
2937
2938/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
2939/// global in the specified llvm.used list.
2940void AsmPrinter::emitLLVMUsedList(const ConstantArray *InitList) {
2941 // Should be an array of 'i8*'.
2942 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
2943 const GlobalValue *GV =
2944 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
2945 if (GV)
2946 OutStreamer->emitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
2947 }
2948}
2949
2951 const Constant *List,
2952 SmallVector<Structor, 8> &Structors) {
2953 // Should be an array of '{ i32, void ()*, i8* }' structs. The first value is
2954 // the init priority.
2955 if (!isa<ConstantArray>(List))
2956 return;
2957
2958 // Gather the structors in a form that's convenient for sorting by priority.
2959 for (Value *O : cast<ConstantArray>(List)->operands()) {
2960 auto *CS = cast<ConstantStruct>(O);
2961 if (CS->getOperand(1)->isNullValue())
2962 break; // Found a null terminator, skip the rest.
2963 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
2964 if (!Priority)
2965 continue; // Malformed.
2966 Structors.push_back(Structor());
2967 Structor &S = Structors.back();
2968 S.Priority = Priority->getLimitedValue(65535);
2969 S.Func = CS->getOperand(1);
2970 if (!CS->getOperand(2)->isNullValue()) {
2971 if (TM.getTargetTriple().isOSAIX())
2973 "associated data of XXStructor list is not yet supported on AIX");
2974 S.ComdatKey =
2975 dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
2976 }
2977 }
2978
2979 // Emit the function pointers in the target-specific order
2980 llvm::stable_sort(Structors, [](const Structor &L, const Structor &R) {
2981 return L.Priority < R.Priority;
2982 });
2983}
2984
2985/// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
2986/// priority.
2988 bool IsCtor) {
2989 SmallVector<Structor, 8> Structors;
2990 preprocessXXStructorList(DL, List, Structors);
2991 if (Structors.empty())
2992 return;
2993
2994 // Emit the structors in reverse order if we are using the .ctor/.dtor
2995 // initialization scheme.
2996 if (!TM.Options.UseInitArray)
2997 std::reverse(Structors.begin(), Structors.end());
2998
2999 const Align Align = DL.getPointerPrefAlignment();
3000 for (Structor &S : Structors) {
3002 const MCSymbol *KeySym = nullptr;
3003 if (GlobalValue *GV = S.ComdatKey) {
3004 if (GV->isDeclarationForLinker())
3005 // If the associated variable is not defined in this module
3006 // (it might be available_externally, or have been an
3007 // available_externally definition that was dropped by the
3008 // EliminateAvailableExternally pass), some other TU
3009 // will provide its dynamic initializer.
3010 continue;
3011
3012 KeySym = getSymbol(GV);
3013 }
3014
3015 MCSection *OutputSection =
3016 (IsCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
3017 : Obj.getStaticDtorSection(S.Priority, KeySym));
3018 OutStreamer->switchSection(OutputSection);
3019 if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
3021 emitXXStructor(DL, S.Func);
3022 }
3023}
3024
3025void AsmPrinter::emitModuleIdents(Module &M) {
3026 if (!MAI->hasIdentDirective())
3027 return;
3028
3029 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
3030 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
3031 const MDNode *N = NMD->getOperand(i);
3032 assert(N->getNumOperands() == 1 &&
3033 "llvm.ident metadata entry can have only one operand");
3034 const MDString *S = cast<MDString>(N->getOperand(0));
3035 OutStreamer->emitIdent(S->getString());
3036 }
3037 }
3038}
3039
3040void AsmPrinter::emitModuleCommandLines(Module &M) {
3042 if (!CommandLine)
3043 return;
3044
3045 const NamedMDNode *NMD = M.getNamedMetadata("llvm.commandline");
3046 if (!NMD || !NMD->getNumOperands())
3047 return;
3048
3049 OutStreamer->pushSection();
3050 OutStreamer->switchSection(CommandLine);
3051 OutStreamer->emitZeros(1);
3052 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
3053 const MDNode *N = NMD->getOperand(i);
3054 assert(N->getNumOperands() == 1 &&
3055 "llvm.commandline metadata entry can have only one operand");
3056 const MDString *S = cast<MDString>(N->getOperand(0));
3057 OutStreamer->emitBytes(S->getString());
3058 OutStreamer->emitZeros(1);
3059 }
3060 OutStreamer->popSection();
3061}
3062
3063//===--------------------------------------------------------------------===//
3064// Emission and print routines
3065//
3066
3067/// Emit a byte directive and value.
3068///
3069void AsmPrinter::emitInt8(int Value) const { OutStreamer->emitInt8(Value); }
3070
3071/// Emit a short directive and value.
3072void AsmPrinter::emitInt16(int Value) const { OutStreamer->emitInt16(Value); }
3073
3074/// Emit a long directive and value.
3075void AsmPrinter::emitInt32(int Value) const { OutStreamer->emitInt32(Value); }
3076
3077/// EmitSLEB128 - emit the specified signed leb128 value.
3078void AsmPrinter::emitSLEB128(int64_t Value, const char *Desc) const {
3079 if (isVerbose() && Desc)
3080 OutStreamer->AddComment(Desc);
3081
3082 OutStreamer->emitSLEB128IntValue(Value);
3083}
3084
3086 unsigned PadTo) const {
3087 if (isVerbose() && Desc)
3088 OutStreamer->AddComment(Desc);
3089
3090 OutStreamer->emitULEB128IntValue(Value, PadTo);
3091}
3092
3093/// Emit a long long directive and value.
3095 OutStreamer->emitInt64(Value);
3096}
3097
3098/// Emit something like ".long Hi-Lo" where the size in bytes of the directive
3099/// is specified by Size and Hi/Lo specify the labels. This implicitly uses
3100/// .set if it avoids relocations.
3102 unsigned Size) const {
3103 OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
3104}
3105
3106/// Emit something like ".uleb128 Hi-Lo".
3108 const MCSymbol *Lo) const {
3109 OutStreamer->emitAbsoluteSymbolDiffAsULEB128(Hi, Lo);
3110}
3111
3112/// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
3113/// where the size in bytes of the directive is specified by Size and Label
3114/// specifies the label. This implicitly uses .set if it is available.
3116 unsigned Size,
3117 bool IsSectionRelative) const {
3118 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
3119 OutStreamer->emitCOFFSecRel32(Label, Offset);
3120 if (Size > 4)
3121 OutStreamer->emitZeros(Size - 4);
3122 return;
3123 }
3124
3125 // Emit Label+Offset (or just Label if Offset is zero)
3126 const MCExpr *Expr = MCSymbolRefExpr::create(Label, OutContext);
3127 if (Offset)
3130
3131 OutStreamer->emitValue(Expr, Size);
3132}
3133
3134//===----------------------------------------------------------------------===//
3135
3136// EmitAlignment - Emit an alignment directive to the specified power of
3137// two boundary. If a global value is specified, and if that global has
3138// an explicit alignment requested, it will override the alignment request
3139// if required for correctness.
3141 unsigned MaxBytesToEmit) const {
3142 if (GV)
3143 Alignment = getGVAlignment(GV, GV->getParent()->getDataLayout(), Alignment);
3144
3145 if (Alignment == Align(1))
3146 return; // 1-byte aligned: no need to emit alignment.
3147
3148 if (getCurrentSection()->getKind().isText()) {
3149 const MCSubtargetInfo *STI = nullptr;
3150 if (this->MF)
3151 STI = &getSubtargetInfo();
3152 else
3153 STI = TM.getMCSubtargetInfo();
3154 OutStreamer->emitCodeAlignment(Alignment, STI, MaxBytesToEmit);
3155 } else
3156 OutStreamer->emitValueToAlignment(Alignment, 0, 1, MaxBytesToEmit);
3157}
3158
3159//===----------------------------------------------------------------------===//
3160// Constant emission.
3161//===----------------------------------------------------------------------===//
3162
3164 MCContext &Ctx = OutContext;
3165
3166 if (CV->isNullValue() || isa<UndefValue>(CV))
3167 return MCConstantExpr::create(0, Ctx);
3168
3169 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
3170 return MCConstantExpr::create(CI->getZExtValue(), Ctx);
3171
3172 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
3173 return MCSymbolRefExpr::create(getSymbol(GV), Ctx);
3174
3175 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
3177
3178 if (const auto *Equiv = dyn_cast<DSOLocalEquivalent>(CV))
3180
3181 if (const NoCFIValue *NC = dyn_cast<NoCFIValue>(CV))
3182 return MCSymbolRefExpr::create(getSymbol(NC->getGlobalValue()), Ctx);
3183
3184 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
3185 if (!CE) {
3186 llvm_unreachable("Unknown constant value to lower!");
3187 }
3188
3189 // The constant expression opcodes are limited to those that are necessary
3190 // to represent relocations on supported targets. Expressions involving only
3191 // constant addresses are constant folded instead.
3192 switch (CE->getOpcode()) {
3193 default:
3194 break; // Error
3195 case Instruction::AddrSpaceCast: {
3196 const Constant *Op = CE->getOperand(0);
3197 unsigned DstAS = CE->getType()->getPointerAddressSpace();
3198 unsigned SrcAS = Op->getType()->getPointerAddressSpace();
3199 if (TM.isNoopAddrSpaceCast(SrcAS, DstAS))
3200 return lowerConstant(Op);
3201
3202 break; // Error
3203 }
3204 case Instruction::GetElementPtr: {
3205 // Generate a symbolic expression for the byte address
3206 APInt OffsetAI(getDataLayout().getPointerTypeSizeInBits(CE->getType()), 0);
3207 cast<GEPOperator>(CE)->accumulateConstantOffset(getDataLayout(), OffsetAI);
3208
3209 const MCExpr *Base = lowerConstant(CE->getOperand(0));
3210 if (!OffsetAI)
3211 return Base;
3212
3213 int64_t Offset = OffsetAI.getSExtValue();
3215 Ctx);
3216 }
3217
3218 case Instruction::Trunc:
3219 // We emit the value and depend on the assembler to truncate the generated
3220 // expression properly. This is important for differences between
3221 // blockaddress labels. Since the two labels are in the same function, it
3222 // is reasonable to treat their delta as a 32-bit value.
3223 [[fallthrough]];
3224 case Instruction::BitCast:
3225 return lowerConstant(CE->getOperand(0));
3226
3227 case Instruction::IntToPtr: {
3228 const DataLayout &DL = getDataLayout();
3229
3230 // Handle casts to pointers by changing them into casts to the appropriate
3231 // integer type. This promotes constant folding and simplifies this code.
3232 Constant *Op = CE->getOperand(0);
3233 Op = ConstantFoldIntegerCast(Op, DL.getIntPtrType(CV->getType()),
3234 /*IsSigned*/ false, DL);
3235 if (Op)
3236 return lowerConstant(Op);
3237
3238 break; // Error
3239 }
3240
3241 case Instruction::PtrToInt: {
3242 const DataLayout &DL = getDataLayout();
3243
3244 // Support only foldable casts to/from pointers that can be eliminated by
3245 // changing the pointer to the appropriately sized integer type.
3246 Constant *Op = CE->getOperand(0);
3247 Type *Ty = CE->getType();
3248
3249 const MCExpr *OpExpr = lowerConstant(Op);
3250
3251 // We can emit the pointer value into this slot if the slot is an
3252 // integer slot equal to the size of the pointer.
3253 //
3254 // If the pointer is larger than the resultant integer, then
3255 // as with Trunc just depend on the assembler to truncate it.
3256 if (DL.getTypeAllocSize(Ty).getFixedValue() <=
3257 DL.getTypeAllocSize(Op->getType()).getFixedValue())
3258 return OpExpr;
3259
3260 break; // Error
3261 }
3262
3263 case Instruction::Sub: {
3264 GlobalValue *LHSGV;
3265 APInt LHSOffset;
3266 DSOLocalEquivalent *DSOEquiv;
3267 if (IsConstantOffsetFromGlobal(CE->getOperand(0), LHSGV, LHSOffset,
3268 getDataLayout(), &DSOEquiv)) {
3269 GlobalValue *RHSGV;
3270 APInt RHSOffset;
3271 if (IsConstantOffsetFromGlobal(CE->getOperand(1), RHSGV, RHSOffset,
3272 getDataLayout())) {
3273 const MCExpr *RelocExpr =
3275 if (!RelocExpr) {
3276 const MCExpr *LHSExpr =
3278 if (DSOEquiv &&
3279 getObjFileLowering().supportDSOLocalEquivalentLowering())
3280 LHSExpr =
3282 RelocExpr = MCBinaryExpr::createSub(
3283 LHSExpr, MCSymbolRefExpr::create(getSymbol(RHSGV), Ctx), Ctx);
3284 }
3285 int64_t Addend = (LHSOffset - RHSOffset).getSExtValue();
3286 if (Addend != 0)
3287 RelocExpr = MCBinaryExpr::createAdd(
3288 RelocExpr, MCConstantExpr::create(Addend, Ctx), Ctx);
3289 return RelocExpr;
3290 }
3291 }
3292
3293 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
3294 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
3295 return MCBinaryExpr::createSub(LHS, RHS, Ctx);
3296 break;
3297 }
3298
3299 case Instruction::Add: {
3300 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
3301 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
3302 return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
3303 }
3304 }
3305
3306 // If the code isn't optimized, there may be outstanding folding
3307 // opportunities. Attempt to fold the expression using DataLayout as a
3308 // last resort before giving up.
3310 if (C != CE)
3311 return lowerConstant(C);
3312
3313 // Otherwise report the problem to the user.
3314 std::string S;
3316 OS << "Unsupported expression in static initializer: ";
3317 CE->printAsOperand(OS, /*PrintType=*/false,
3318 !MF ? nullptr : MF->getFunction().getParent());
3319 report_fatal_error(Twine(OS.str()));
3320}
3321
3322static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
3323 AsmPrinter &AP,
3324 const Constant *BaseCV = nullptr,
3325 uint64_t Offset = 0,
3326 AsmPrinter::AliasMapTy *AliasList = nullptr);
3327
3328static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP);
3329static void emitGlobalConstantFP(APFloat APF, Type *ET, AsmPrinter &AP);
3330
3331/// isRepeatedByteSequence - Determine whether the given value is
3332/// composed of a repeated sequence of identical bytes and return the
3333/// byte value. If it is not a repeated sequence, return -1.
3335 StringRef Data = V->getRawDataValues();
3336 assert(!Data.empty() && "Empty aggregates should be CAZ node");
3337 char C = Data[0];
3338 for (unsigned i = 1, e = Data.size(); i != e; ++i)
3339 if (Data[i] != C) return -1;
3340 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
3341}
3342
3343/// isRepeatedByteSequence - Determine whether the given value is
3344/// composed of a repeated sequence of identical bytes and return the
3345/// byte value. If it is not a repeated sequence, return -1.
3346static int isRepeatedByteSequence(const Value *V, const DataLayout &DL) {
3347 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
3348 uint64_t Size = DL.getTypeAllocSizeInBits(V->getType());
3349 assert(Size % 8 == 0);
3350
3351 // Extend the element to take zero padding into account.
3352 APInt Value = CI->getValue().zext(Size);
3353 if (!Value.isSplat(8))
3354 return -1;
3355
3356 return Value.zextOrTrunc(8).getZExtValue();
3357 }
3358 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
3359 // Make sure all array elements are sequences of the same repeated
3360 // byte.
3361 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
3362 Constant *Op0 = CA->getOperand(0);
3363 int Byte = isRepeatedByteSequence(Op0, DL);
3364 if (Byte == -1)
3365 return -1;
3366
3367 // All array elements must be equal.
3368 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
3369 if (CA->getOperand(i) != Op0)
3370 return -1;
3371 return Byte;
3372 }
3373
3374 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
3375 return isRepeatedByteSequence(CDS);
3376
3377 return -1;
3378}
3379
3381 AsmPrinter::AliasMapTy *AliasList) {
3382 if (AliasList) {
3383 auto AliasIt = AliasList->find(Offset);
3384 if (AliasIt != AliasList->end()) {
3385 for (const GlobalAlias *GA : AliasIt->second)
3386 AP.OutStreamer->emitLabel(AP.getSymbol(GA));
3387 AliasList->erase(Offset);
3388 }
3389 }
3390}
3391
3393 const DataLayout &DL, const ConstantDataSequential *CDS, AsmPrinter &AP,
3394 AsmPrinter::AliasMapTy *AliasList) {
3395 // See if we can aggregate this into a .fill, if so, emit it as such.
3396 int Value = isRepeatedByteSequence(CDS, DL);
3397 if (Value != -1) {
3398 uint64_t Bytes = DL.getTypeAllocSize(CDS->getType());
3399 // Don't emit a 1-byte object as a .fill.
3400 if (Bytes > 1)
3401 return AP.OutStreamer->emitFill(Bytes, Value);
3402 }
3403
3404 // If this can be emitted with .ascii/.asciz, emit it as such.
3405 if (CDS->isString())
3406 return AP.OutStreamer->emitBytes(CDS->getAsString());
3407
3408 // Otherwise, emit the values in successive locations.
3409 unsigned ElementByteSize = CDS->getElementByteSize();
3410 if (isa<IntegerType>(CDS->getElementType())) {
3411 for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I) {
3412 emitGlobalAliasInline(AP, ElementByteSize * I, AliasList);
3413 if (AP.isVerbose())
3414 AP.OutStreamer->getCommentOS()
3415 << format("0x%" PRIx64 "\n", CDS->getElementAsInteger(I));
3416 AP.OutStreamer->emitIntValue(CDS->getElementAsInteger(I),
3417 ElementByteSize);
3418 }
3419 } else {
3420 Type *ET = CDS->getElementType();
3421 for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I) {
3422 emitGlobalAliasInline(AP, ElementByteSize * I, AliasList);
3424 }
3425 }
3426
3427 unsigned Size = DL.getTypeAllocSize(CDS->getType());
3428 unsigned EmittedSize =
3429 DL.getTypeAllocSize(CDS->getElementType()) * CDS->getNumElements();
3430 assert(EmittedSize <= Size && "Size cannot be less than EmittedSize!");
3431 if (unsigned Padding = Size - EmittedSize)
3432 AP.OutStreamer->emitZeros(Padding);
3433}
3434
3436 const ConstantArray *CA, AsmPrinter &AP,
3437 const Constant *BaseCV, uint64_t Offset,
3438 AsmPrinter::AliasMapTy *AliasList) {
3439 // See if we can aggregate some values. Make sure it can be
3440 // represented as a series of bytes of the constant value.
3441 int Value = isRepeatedByteSequence(CA, DL);
3442
3443 if (Value != -1) {
3444 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
3445 AP.OutStreamer->emitFill(Bytes, Value);
3446 } else {
3447 for (unsigned I = 0, E = CA->getNumOperands(); I != E; ++I) {
3448 emitGlobalConstantImpl(DL, CA->getOperand(I), AP, BaseCV, Offset,
3449 AliasList);
3450 Offset += DL.getTypeAllocSize(CA->getOperand(I)->getType());
3451 }
3452 }
3453}
3454
3455static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP);
3456
3458 const ConstantVector *CV, AsmPrinter &AP,
3459 AsmPrinter::AliasMapTy *AliasList) {
3460 Type *ElementType = CV->getType()->getElementType();
3461 uint64_t ElementSizeInBits = DL.getTypeSizeInBits(ElementType);
3462 uint64_t ElementAllocSizeInBits = DL.getTypeAllocSizeInBits(ElementType);
3463 uint64_t EmittedSize;
3464 if (ElementSizeInBits != ElementAllocSizeInBits) {
3465 // If the allocation size of an element is different from the size in bits,
3466 // printing each element separately will insert incorrect padding.
3467 //
3468 // The general algorithm here is complicated; instead of writing it out
3469 // here, just use the existing code in ConstantFolding.
3470 Type *IntT =
3471 IntegerType::get(CV->getContext(), DL.getTypeSizeInBits(CV->getType()));
3472 ConstantInt *CI = dyn_cast_or_null<ConstantInt>(ConstantFoldConstant(
3473 ConstantExpr::getBitCast(const_cast<ConstantVector *>(CV), IntT), DL));
3474 if (!CI) {
3476 "Cannot lower vector global with unusual element type");
3477 }
3478 emitGlobalAliasInline(AP, 0, AliasList);
3480 EmittedSize = DL.getTypeStoreSize(CV->getType());
3481 } else {
3482 for (unsigned I = 0, E = CV->getType()->getNumElements(); I != E; ++I) {
3483 emitGlobalAliasInline(AP, DL.getTypeAllocSize(CV->getType()) * I, AliasList);
3485 }
3486 EmittedSize =
3487 DL.getTypeAllocSize(ElementType) * CV->getType()->getNumElements();
3488 }
3489
3490 unsigned Size = DL.getTypeAllocSize(CV->getType());
3491 if (unsigned Padding = Size - EmittedSize)
3492 AP.OutStreamer->emitZeros(Padding);
3493}
3494
3496 const ConstantStruct *CS, AsmPrinter &AP,
3497 const Constant *BaseCV, uint64_t Offset,
3498 AsmPrinter::AliasMapTy *AliasList) {
3499 // Print the fields in successive locations. Pad to align if needed!
3500 unsigned Size = DL.getTypeAllocSize(CS->getType());
3501 const StructLayout *Layout = DL.getStructLayout(CS->getType());
3502 uint64_t SizeSoFar = 0;
3503 for (unsigned I = 0, E = CS->getNumOperands(); I != E; ++I) {
3504 const Constant *Field = CS->getOperand(I);
3505
3506 // Print the actual field value.
3507 emitGlobalConstantImpl(DL, Field, AP, BaseCV, Offset + SizeSoFar,
3508 AliasList);
3509
3510 // Check if padding is needed and insert one or more 0s.
3511 uint64_t FieldSize = DL.getTypeAllocSize(Field->getType());
3512 uint64_t PadSize = ((I == E - 1 ? Size : Layout->getElementOffset(I + 1)) -
3513 Layout->getElementOffset(I)) -
3514 FieldSize;
3515 SizeSoFar += FieldSize + PadSize;
3516
3517 // Insert padding - this may include padding to increase the size of the
3518 // current field up to the ABI size (if the struct is not packed) as well
3519 // as padding to ensure that the next field starts at the right offset.
3520 AP.OutStreamer->emitZeros(PadSize);
3521 }
3522 assert(SizeSoFar == Layout->getSizeInBytes() &&
3523 "Layout of constant struct may be incorrect!");
3524}
3525
3526static void emitGlobalConstantFP(APFloat APF, Type *ET, AsmPrinter &AP) {
3527 assert(ET && "Unknown float type");
3528 APInt API = APF.bitcastToAPInt();
3529
3530 // First print a comment with what we think the original floating-point value
3531 // should have been.
3532 if (AP.isVerbose()) {
3533 SmallString<8> StrVal;
3534 APF.toString(StrVal);
3535 ET->print(AP.OutStreamer->getCommentOS());
3536 AP.OutStreamer->getCommentOS() << ' ' << StrVal << '\n';
3537 }
3538
3539 // Now iterate through the APInt chunks, emitting them in endian-correct
3540 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
3541 // floats).
3542 unsigned NumBytes = API.getBitWidth() / 8;
3543 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
3544 const uint64_t *p = API.getRawData();
3545
3546 // PPC's long double has odd notions of endianness compared to how LLVM
3547 // handles it: p[0] goes first for *big* endian on PPC.
3548 if (AP.getDataLayout().isBigEndian() && !ET->isPPC_FP128Ty()) {
3549 int Chunk = API.getNumWords() - 1;
3550
3551 if (TrailingBytes)
3552 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk--], TrailingBytes);
3553
3554 for (; Chunk >= 0; --Chunk)
3555 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk], sizeof(uint64_t));
3556 } else {
3557 unsigned Chunk;
3558 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
3559 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk], sizeof(uint64_t));
3560
3561 if (TrailingBytes)
3562 AP.OutStreamer->emitIntValueInHexWithPadding(p[Chunk], TrailingBytes);
3563 }
3564
3565 // Emit the tail padding for the long double.
3566 const DataLayout &DL = AP.getDataLayout();
3567 AP.OutStreamer->emitZeros(DL.getTypeAllocSize(ET) - DL.getTypeStoreSize(ET));
3568}
3569
3570static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
3571 emitGlobalConstantFP(CFP->getValueAPF(), CFP->getType(), AP);
3572}
3573
3575 const DataLayout &DL = AP.getDataLayout();
3576 unsigned BitWidth = CI->getBitWidth();
3577
3578 // Copy the value as we may massage the layout for constants whose bit width
3579 // is not a multiple of 64-bits.
3580 APInt Realigned(CI->getValue());
3581 uint64_t ExtraBits = 0;
3582 unsigned ExtraBitsSize = BitWidth & 63;
3583
3584 if (ExtraBitsSize) {
3585 // The bit width of the data is not a multiple of 64-bits.
3586 // The extra bits are expected to be at the end of the chunk of the memory.
3587 // Little endian:
3588 // * Nothing to be done, just record the extra bits to emit.
3589 // Big endian:
3590 // * Record the extra bits to emit.
3591 // * Realign the raw data to emit the chunks of 64-bits.
3592 if (DL.isBigEndian()) {
3593 // Basically the structure of the raw data is a chunk of 64-bits cells:
3594 // 0 1 BitWidth / 64
3595 // [chunk1][chunk2] ... [chunkN].
3596 // The most significant chunk is chunkN and it should be emitted first.
3597 // However, due to the alignment issue chunkN contains useless bits.
3598 // Realign the chunks so that they contain only useful information:
3599 // ExtraBits 0 1 (BitWidth / 64) - 1
3600 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
3601 ExtraBitsSize = alignTo(ExtraBitsSize, 8);
3602 ExtraBits = Realigned.getRawData()[0] &
3603 (((uint64_t)-1) >> (64 - ExtraBitsSize));
3604 if (BitWidth >= 64)
3605 Realigned.lshrInPlace(ExtraBitsSize);
3606 } else
3607 ExtraBits = Realigned.getRawData()[BitWidth / 64];
3608 }
3609
3610 // We don't expect assemblers to support integer data directives
3611 // for more than 64 bits, so we emit the data in at most 64-bit
3612 // quantities at a time.
3613 const uint64_t *RawData = Realigned.getRawData();
3614 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
3615 uint64_t Val = DL.isBigEndian() ? RawData[e - i - 1] : RawData[i];
3616 AP.OutStreamer->emitIntValue(Val, 8);
3617 }
3618
3619 if (ExtraBitsSize) {
3620 // Emit the extra bits after the 64-bits chunks.
3621
3622 // Emit a directive that fills the expected size.
3624 Size -= (BitWidth / 64) * 8;
3625 assert(Size && Size * 8 >= ExtraBitsSize &&
3626 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
3627 == ExtraBits && "Directive too small for extra bits.");
3628 AP.OutStreamer->emitIntValue(ExtraBits, Size);
3629 }
3630}
3631
3632/// Transform a not absolute MCExpr containing a reference to a GOT
3633/// equivalent global, by a target specific GOT pc relative access to the
3634/// final symbol.
3636 const Constant *BaseCst,
3637 uint64_t Offset) {
3638 // The global @foo below illustrates a global that uses a got equivalent.
3639 //
3640 // @bar = global i32 42
3641 // @gotequiv = private unnamed_addr constant i32* @bar
3642 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
3643 // i64 ptrtoint (i32* @foo to i64))
3644 // to i32)
3645 //
3646 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
3647 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
3648 // form:
3649 //
3650 // foo = cstexpr, where
3651 // cstexpr := <gotequiv> - "." + <cst>
3652 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
3653 //
3654 // After canonicalization by evaluateAsRelocatable `ME` turns into:
3655 //
3656 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
3657 // gotpcrelcst := <offset from @foo base> + <cst>
3658 MCValue MV;
3659 if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
3660 return;
3661 const MCSymbolRefExpr *SymA = MV.getSymA();
3662 if (!SymA)
3663 return;
3664
3665 // Check that GOT equivalent symbol is cached.
3666 const MCSymbol *GOTEquivSym = &SymA->getSymbol();
3667 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
3668 return;
3669
3670 const GlobalValue *BaseGV = dyn_cast_or_null<GlobalValue>(BaseCst);
3671 if (!BaseGV)
3672 return;
3673
3674 // Check for a valid base symbol
3675 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
3676 const MCSymbolRefExpr *SymB = MV.getSymB();
3677
3678 if (!SymB || BaseSym != &SymB->getSymbol())
3679 return;
3680
3681 // Make sure to match:
3682 //
3683 // gotpcrelcst := <offset from @foo base> + <cst>
3684 //
3685 int64_t GOTPCRelCst = Offset + MV.getConstant();
3686 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
3687 return;
3688
3689 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
3690 //
3691 // bar:
3692 // .long 42
3693 // gotequiv:
3694 // .quad bar
3695 // foo:
3696 // .long gotequiv - "." + <cst>
3697 //
3698 // is replaced by the target specific equivalent to:
3699 //
3700 // bar:
3701 // .long 42
3702 // foo:
3703 // .long bar@GOTPCREL+<gotpcrelcst>
3704 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
3705 const GlobalVariable *GV = Result.first;
3706 int NumUses = (int)Result.second;
3707 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
3708 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
3710 FinalGV, FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
3711
3712 // Update GOT equivalent usage information
3713 --NumUses;
3714 if (NumUses >= 0)
3715 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
3716}
3717
3718static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *CV,
3719 AsmPrinter &AP, const Constant *BaseCV,
3721 AsmPrinter::AliasMapTy *AliasList) {
3722 emitGlobalAliasInline(AP, Offset, AliasList);
3723 uint64_t Size = DL.getTypeAllocSize(CV->getType());
3724
3725 // Globals with sub-elements such as combinations of arrays and structs
3726 // are handled recursively by emitGlobalConstantImpl. Keep track of the
3727 // constant symbol base and the current position with BaseCV and Offset.
3728 if (!BaseCV && CV->hasOneUse())
3729 BaseCV = dyn_cast<Constant>(CV->user_back());
3730
3731 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
3732 return AP.OutStreamer->emitZeros(Size);
3733
3734 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
3735 const uint64_t StoreSize = DL.getTypeStoreSize(CV->getType());
3736
3737 if (StoreSize <= 8) {
3738 if (AP.isVerbose())
3739 AP.OutStreamer->getCommentOS()
3740 << format("0x%" PRIx64 "\n", CI->getZExtValue());
3741 AP.OutStreamer->emitIntValue(CI->getZExtValue(), StoreSize);
3742 } else {
3744 }
3745
3746 // Emit tail padding if needed
3747 if (Size != StoreSize)
3748 AP.OutStreamer->emitZeros(Size - StoreSize);
3749
3750 return;
3751 }
3752
3753 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
3754 return emitGlobalConstantFP(CFP, AP);
3755
3756 if (isa<ConstantPointerNull>(CV)) {
3757 AP.OutStreamer->emitIntValue(0, Size);
3758 return;
3759 }
3760
3761 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
3762 return emitGlobalConstantDataSequential(DL, CDS, AP, AliasList);
3763
3764 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
3765 return emitGlobalConstantArray(DL, CVA, AP, BaseCV, Offset, AliasList);
3766
3767 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
3768 return emitGlobalConstantStruct(DL, CVS, AP, BaseCV, Offset, AliasList);
3769
3770 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
3771 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
3772 // vectors).
3773 if (CE->getOpcode() == Instruction::BitCast)
3774 return emitGlobalConstantImpl(DL, CE->getOperand(0), AP);
3775
3776 if (Size > 8) {
3777 // If the constant expression's size is greater than 64-bits, then we have
3778 // to emit the value in chunks. Try to constant fold the value and emit it
3779 // that way.
3780 Constant *New = ConstantFoldConstant(CE, DL);
3781 if (New != CE)
3782 return emitGlobalConstantImpl(DL, New, AP);
3783 }
3784 }
3785
3786 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
3787 return emitGlobalConstantVector(DL, V, AP, AliasList);
3788
3789 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
3790 // thread the streamer with EmitValue.
3791 const MCExpr *ME = AP.lowerConstant(CV);
3792
3793 // Since lowerConstant already folded and got rid of all IR pointer and
3794 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
3795 // directly.
3797 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
3798
3799 AP.OutStreamer->emitValue(ME, Size);
3800}
3801
3802/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
3804 AliasMapTy *AliasList) {
3805 uint64_t Size = DL.getTypeAllocSize(CV->getType());
3806 if (Size)
3807 emitGlobalConstantImpl(DL, CV, *this, nullptr, 0, AliasList);
3808 else if (MAI->hasSubsectionsViaSymbols()) {
3809 // If the global has zero size, emit a single byte so that two labels don't
3810 // look like they are at the same location.
3811 OutStreamer->emitIntValue(0, 1);
3812 }
3813 if (!AliasList)
3814 return;
3815 // TODO: These remaining aliases are not emitted in the correct location. Need
3816 // to handle the case where the alias offset doesn't refer to any sub-element.
3817 for (auto &AliasPair : *AliasList) {
3818 for (const GlobalAlias *GA : AliasPair.second)
3819 OutStreamer->emitLabel(getSymbol(GA));
3820 }
3821}
3822
3824 // Target doesn't support this yet!
3825 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
3826}
3827
3829 if (Offset > 0)
3830 OS << '+' << Offset;
3831 else if (Offset < 0)
3832 OS << Offset;
3833}
3834
3835void AsmPrinter::emitNops(unsigned N) {
3837 for (; N; --N)
3839}
3840
3841//===----------------------------------------------------------------------===//
3842// Symbol Lowering Routines.
3843//===----------------------------------------------------------------------===//
3844
3846 return OutContext.createTempSymbol(Name, true);
3847}
3848
3850 return const_cast<AsmPrinter *>(this)->getAddrLabelSymbol(
3851 BA->getBasicBlock());
3852}
3853
3855 return const_cast<AsmPrinter *>(this)->getAddrLabelSymbol(BB);
3856}
3857
3858/// GetCPISymbol - Return the symbol for the specified constant pool entry.
3859MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
3860 if (getSubtargetInfo().getTargetTriple().isWindowsMSVCEnvironment()) {
3861 const MachineConstantPoolEntry &CPE =
3862 MF->getConstantPool()->getConstants()[CPID];
3863 if (!CPE.isMachineConstantPoolEntry()) {
3864 const DataLayout &DL = MF->getDataLayout();
3865 SectionKind Kind = CPE.getSectionKind(&DL);
3866 const Constant *C = CPE.Val.ConstVal;
3867 Align Alignment = CPE.Alignment;
3868 if (const MCSectionCOFF *S = dyn_cast<MCSectionCOFF>(
3869 getObjFileLowering().getSectionForConstant(DL, Kind, C,
3870 Alignment))) {
3871 if (MCSymbol *Sym = S->getCOMDATSymbol()) {
3872 if (Sym->isUndefined())
3873 OutStreamer->emitSymbolAttribute(Sym, MCSA_Global);
3874 return Sym;
3875 }
3876 }
3877 }
3878 }
3879
3880 const DataLayout &DL = getDataLayout();
3881 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
3882 "CPI" + Twine(getFunctionNumber()) + "_" +
3883 Twine(CPID));
3884}
3885
3886/// GetJTISymbol - Return the symbol for the specified jump table entry.
3887MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
3888 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
3889}
3890
3891/// GetJTSetSymbol - Return the symbol for the specified jump table .set
3892/// FIXME: privatize to AsmPrinter.
3893MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
3894 const DataLayout &DL = getDataLayout();
3895 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
3896 Twine(getFunctionNumber()) + "_" +
3897 Twine(UID) + "_set_" + Twine(MBBID));
3898}
3899
3901 StringRef Suffix) const {
3903}
3904
3905/// Return the MCSymbol for the specified ExternalSymbol.
3907 SmallString<60> NameStr;
3909 return OutContext.getOrCreateSymbol(NameStr);
3910}
3911
3912/// PrintParentLoopComment - Print comments about parent loops of this one.
3914 unsigned FunctionNumber) {
3915 if (!Loop) return;
3916 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
3918 << "Parent Loop BB" << FunctionNumber << "_"
3919 << Loop->getHeader()->getNumber()
3920 << " Depth=" << Loop->getLoopDepth() << '\n';
3921}
3922
3923/// PrintChildLoopComment - Print comments about child loops within
3924/// the loop for this basic block, with nesting.
3926 unsigned FunctionNumber) {
3927 // Add child loop information
3928 for (const MachineLoop *CL : *Loop) {
3929 OS.indent(CL->getLoopDepth()*2)
3930 << "Child Loop BB" << FunctionNumber << "_"
3931 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
3932 << '\n';
3933 PrintChildLoopComment(OS, CL, FunctionNumber);
3934 }
3935}
3936
3937/// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
3939 const MachineLoopInfo *LI,
3940 const AsmPrinter &AP) {
3941 // Add loop depth information
3942 const MachineLoop *Loop = LI->getLoopFor(&MBB);
3943 if (!Loop) return;
3944
3945 MachineBasicBlock *Header = Loop->getHeader();
3946 assert(Header && "No header for loop");
3947
3948 // If this block is not a loop header, just print out what is the loop header
3949 // and return.
3950 if (Header != &MBB) {
3951 AP.OutStreamer->AddComment(" in Loop: Header=BB" +
3952 Twine(AP.getFunctionNumber())+"_" +
3953 Twine(Loop->getHeader()->getNumber())+
3954 " Depth="+Twine(Loop->getLoopDepth()));
3955 return;
3956 }
3957
3958 // Otherwise, it is a loop header. Print out information about child and
3959 // parent loops.
3960 raw_ostream &OS = AP.OutStreamer->getCommentOS();
3961
3963
3964 OS << "=>";
3965 OS.indent(Loop->getLoopDepth()*2-2);
3966
3967 OS << "This ";
3968 if (Loop->isInnermost())
3969 OS << "Inner ";
3970 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
3971
3973}
3974
3975/// emitBasicBlockStart - This method prints the label for the specified
3976/// MachineBasicBlock, an alignment (if present) and a comment describing
3977/// it if appropriate.
3979 // End the previous funclet and start a new one.
3980 if (MBB.isEHFuncletEntry()) {
3981 for (const HandlerInfo &HI : Handlers) {
3982 HI.Handler->endFunclet();
3983 HI.Handler->beginFunclet(MBB);
3984 }
3985 }
3986
3987 // Switch to a new section if this basic block must begin a section. The
3988 // entry block is always placed in the function section and is handled
3989 // separately.
3990 if (MBB.isBeginSection() && !MBB.isEntryBlock()) {
3991 OutStreamer->switchSection(
3992 getObjFileLowering().getSectionForMachineBasicBlock(MF->getFunction(),
3993 MBB, TM));
3994 CurrentSectionBeginSym = MBB.getSymbol();
3995 }
3996
3997 // Emit an alignment directive for this block, if needed.
3998 const Align Alignment = MBB.getAlignment();
3999 if (Alignment != Align(1))
4000 emitAlignment(Alignment, nullptr, MBB.getMaxBytesForAlignment());
4001
4002 // If the block has its address taken, emit any labels that were used to
4003 // reference the block. It is possible that there is more than one label
4004 // here, because multiple LLVM BB's may have been RAUW'd to this block after
4005 // the references were generated.
4006 if (MBB.isIRBlockAddressTaken()) {
4007 if (isVerbose())
4008 OutStreamer->AddComment("Block address taken");
4009
4011 assert(BB && BB->hasAddressTaken() && "Missing BB");
4013 OutStreamer->emitLabel(Sym);
4014 } else if (isVerbose() && MBB.isMachineBlockAddressTaken()) {
4015 OutStreamer->AddComment("Block address taken");
4016 }
4017
4018 // Print some verbose block comments.
4019 if (isVerbose()) {
4020 if (const BasicBlock *BB = MBB.getBasicBlock()) {
4021 if (BB->hasName()) {
4022 BB->printAsOperand(OutStreamer->getCommentOS(),
4023 /*PrintType=*/false, BB->getModule());
4024 OutStreamer->getCommentOS() << '\n';
4025 }
4026 }
4027
4028 assert(MLI != nullptr && "MachineLoopInfo should has been computed");
4030 }
4031
4032 // Print the main label for the block.
4033 if (shouldEmitLabelForBasicBlock(MBB)) {
4035 OutStreamer->AddComment("Label of block must be emitted");
4036 OutStreamer->emitLabel(MBB.getSymbol());
4037 } else {
4038 if (isVerbose()) {
4039 // NOTE: Want this comment at start of line, don't emit with AddComment.
4040 OutStreamer->emitRawComment(" %bb." + Twine(MBB.getNumber()) + ":",
4041 false);
4042 }
4043 }
4044
4045 if (MBB.isEHCatchretTarget() &&
4047 OutStreamer->emitLabel(MBB.getEHCatchretSymbol());
4048 }
4049
4050 // With BB sections, each basic block must handle CFI information on its own
4051 // if it begins a section (Entry block call is handled separately, next to
4052 // beginFunction).
4053 if (MBB.isBeginSection() && !MBB.isEntryBlock())
4054 for (const HandlerInfo &HI : Handlers)
4055 HI.Handler->beginBasicBlockSection(MBB);
4056}
4057
4059 // Check if CFI information needs to be updated for this MBB with basic block
4060 // sections.
4061 if (MBB.isEndSection())
4062 for (const HandlerInfo &HI : Handlers)
4063 HI.Handler->endBasicBlockSection(MBB);
4064}
4065
4066void AsmPrinter::emitVisibility(MCSymbol *Sym, unsigned Visibility,
4067 bool IsDefinition) const {
4069
4070 switch (Visibility) {
4071 default: break;
4073 if (IsDefinition)
4074 Attr = MAI->getHiddenVisibilityAttr();
4075 else
4077 break;
4080 break;
4081 }
4082
4083 if (Attr != MCSA_Invalid)
4084 OutStreamer->emitSymbolAttribute(Sym, Attr);
4085}
4086
4087bool AsmPrinter::shouldEmitLabelForBasicBlock(
4088 const MachineBasicBlock &MBB) const {
4089 // With `-fbasic-block-sections=`, a label is needed for every non-entry block
4090 // in the labels mode (option `=labels`) and every section beginning in the
4091 // sections mode (`=all` and `=list=`).
4092 if ((MF->hasBBLabels() || MF->getTarget().Options.BBAddrMap ||
4093 MBB.isBeginSection()) &&
4094 !MBB.isEntryBlock())
4095 return true;
4096 // A label is needed for any block with at least one predecessor (when that
4097 // predecessor is not the fallthrough predecessor, or if it is an EH funclet
4098 // entry, or if a label is forced).
4099 return !MBB.pred_empty() &&
4102}
4103
4104/// isBlockOnlyReachableByFallthough - Return true if the basic block has
4105/// exactly one predecessor and the control transfer mechanism between
4106/// the predecessor and this block is a fall-through.
4109 // If this is a landing pad, it isn't a fall through. If it has no preds,
4110 // then nothing falls through to it.
4111 if (MBB->isEHPad() || MBB->pred_empty())
4112 return false;
4113
4114 // If there isn't exactly one predecessor, it can't be a fall through.
4115 if (MBB->pred_size() > 1)
4116 return false;
4117
4118 // The predecessor has to be immediately before this block.
4119 MachineBasicBlock *Pred = *MBB->pred_begin();
4120 if (!Pred->isLayoutSuccessor(MBB))
4121 return false;
4122
4123 // If the block is completely empty, then it definitely does fall through.
4124 if (Pred->empty())
4125 return true;
4126
4127 // Check the terminators in the previous blocks
4128 for (const auto &MI : Pred->terminators()) {
4129 // If it is not a simple branch, we are in a table somewhere.
4130 if (!MI.isBranch() || MI.isIndirectBranch())
4131 return false;
4132
4133 // If we are the operands of one of the branches, this is not a fall
4134 // through. Note that targets with delay slots will usually bundle
4135 // terminators with the delay slot instruction.
4136 for (ConstMIBundleOperands OP(MI); OP.isValid(); ++OP) {
4137 if (OP->isJTI())
4138 return false;
4139 if (OP->isMBB() && OP->getMBB() == MBB)
4140 return false;
4141 }
4142 }
4143
4144 return true;
4145}
4146
4147GCMetadataPrinter *AsmPrinter::getOrCreateGCPrinter(GCStrategy &S) {
4148 if (!S.usesMetadata())
4149 return nullptr;
4150
4151 auto [GCPI, Inserted] = GCMetadataPrinters.insert({&S, nullptr});
4152 if (!Inserted)
4153 return GCPI->second.get();
4154
4155 auto Name = S.getName();
4156
4157 for (const GCMetadataPrinterRegistry::entry &GCMetaPrinter :
4159 if (Name == GCMetaPrinter.getName()) {
4160 std::unique_ptr<GCMetadataPrinter> GMP = GCMetaPrinter.instantiate();
4161 GMP->S = &S;
4162 GCPI->second = std::move(GMP);
4163 return GCPI->second.get();
4164 }
4165
4166 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
4167}
4168
4170 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
4171 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
4172 bool NeedsDefault = false;
4173 if (MI->begin() == MI->end())
4174 // No GC strategy, use the default format.
4175 NeedsDefault = true;
4176 else
4177 for (const auto &I : *MI) {
4178 if (GCMetadataPrinter *MP = getOrCreateGCPrinter(*I))
4179 if (MP->emitStackMaps(SM, *this))
4180 continue;
4181 // The strategy doesn't have printer or doesn't emit custom stack maps.
4182 // Use the default format.
4183 NeedsDefault = true;
4184 }
4185
4186 if (NeedsDefault)
4188}
4189
4190/// Pin vtable to this file.
4192
4194
4195// In the binary's "xray_instr_map" section, an array of these function entries
4196// describes each instrumentation point. When XRay patches your code, the index
4197// into this table will be given to your handler as a patch point identifier.
4199 auto Kind8 = static_cast<uint8_t>(Kind);
4200 Out->emitBinaryData(StringRef(reinterpret_cast<const char *>(&Kind8), 1));
4201 Out->emitBinaryData(
4202 StringRef(reinterpret_cast<const char *>(&AlwaysInstrument), 1));
4203 Out->emitBinaryData(StringRef(reinterpret_cast<const char *>(&Version), 1));
4204 auto Padding = (4 * Bytes) - ((2 * Bytes) + 3);
4205 assert(Padding >= 0 && "Instrumentation map entry > 4 * Word Size");
4206 Out->emitZeros(Padding);
4207}
4208
4210 if (Sleds.empty())
4211 return;
4212
4213 auto PrevSection = OutStreamer->getCurrentSectionOnly();
4214 const Function &F = MF->getFunction();
4215 MCSection *InstMap = nullptr;
4216 MCSection *FnSledIndex = nullptr;
4217 const Triple &TT = TM.getTargetTriple();
4218 // Use PC-relative addresses on all targets.
4219 if (TT.isOSBinFormatELF()) {
4220 auto LinkedToSym = cast<MCSymbolELF>(CurrentFnSym);
4221 auto Flags = ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER;
4222 StringRef GroupName;
4223 if (F.hasComdat()) {
4224 Flags |= ELF::SHF_GROUP;
4225 GroupName = F.getComdat()->getName();
4226 }
4227 InstMap = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
4228 Flags, 0, GroupName, F.hasComdat(),
4229 MCSection::NonUniqueID, LinkedToSym);
4230
4232 FnSledIndex = OutContext.getELFSection(
4233 "xray_fn_idx", ELF::SHT_PROGBITS, Flags, 0, GroupName, F.hasComdat(),
4234 MCSection::NonUniqueID, LinkedToSym);
4236 InstMap = OutContext.getMachOSection("__DATA", "xray_instr_map",
4240 FnSledIndex = OutContext.getMachOSection("__DATA", "xray_fn_idx",
4243 } else {
4244 llvm_unreachable("Unsupported target");
4245 }
4246
4247 auto WordSizeBytes = MAI->getCodePointerSize();
4248
4249 // Now we switch to the instrumentation map section. Because this is done
4250 // per-function, we are able to create an index entry that will represent the
4251 // range of sleds associated with a function.
4252 auto &Ctx = OutContext;
4253 MCSymbol *SledsStart =
4254 OutContext.createLinkerPrivateSymbol("xray_sleds_start");
4255 OutStreamer->switchSection(InstMap);
4256 OutStreamer->emitLabel(SledsStart);
4257 for (const auto &Sled : Sleds) {
4258 MCSymbol *Dot = Ctx.createTempSymbol();
4259 OutStreamer->emitLabel(Dot);
4260 OutStreamer->emitValueImpl(
4262 MCSymbolRefExpr::create(Dot, Ctx), Ctx),
4263 WordSizeBytes);
4264 OutStreamer->emitValueImpl(
4268 MCConstantExpr::create(WordSizeBytes, Ctx),
4269 Ctx),
4270 Ctx),
4271 WordSizeBytes);
4272 Sled.emit(WordSizeBytes, OutStreamer.get());
4273 }
4274 MCSymbol *SledsEnd = OutContext.createTempSymbol("xray_sleds_end", true);
4275 OutStreamer->emitLabel(SledsEnd);
4276
4277 // We then emit a single entry in the index per function. We use the symbols
4278 // that bound the instrumentation map as the range for a specific function.
4279 // Each entry here will be 2 * word size aligned, as we're writing down two
4280 // pointers. This should work for both 32-bit and 64-bit platforms.
4281 if (FnSledIndex) {
4282 OutStreamer->switchSection(FnSledIndex);
4283 OutStreamer->emitCodeAlignment(Align(2 * WordSizeBytes),
4284 &getSubtargetInfo());
4285 // For Mach-O, use an "l" symbol as the atom of this subsection. The label
4286 // difference uses a SUBTRACTOR external relocation which references the
4287 // symbol.
4288 MCSymbol *Dot = Ctx.createLinkerPrivateSymbol("xray_fn_idx");
4289 OutStreamer->emitLabel(Dot);
4290 OutStreamer->emitValueImpl(
4292 MCSymbolRefExpr::create(Dot, Ctx), Ctx),
4293 WordSizeBytes);
4294 OutStreamer->emitValueImpl(MCConstantExpr::create(Sleds.size(), Ctx),
4295 WordSizeBytes);
4296 OutStreamer->switchSection(PrevSection);
4297 }
4298 Sleds.clear();
4299}
4300
4302 SledKind Kind, uint8_t Version) {
4303 const Function &F = MI.getMF()->getFunction();
4304 auto Attr = F.getFnAttribute("function-instrument");
4305 bool LogArgs = F.hasFnAttribute("xray-log-args");
4306 bool AlwaysInstrument =
4307 Attr.isStringAttribute() && Attr.getValueAsString() == "xray-always";
4308 if (Kind == SledKind::FUNCTION_ENTER && LogArgs)
4310 Sleds.emplace_back(XRayFunctionEntry{Sled, CurrentFnSym, Kind,
4311 AlwaysInstrument, &F, Version});
4312}
4313
4315 const Function &F = MF->getFunction();
4316 unsigned PatchableFunctionPrefix = 0, PatchableFunctionEntry = 0;
4317 (void)F.getFnAttribute("patchable-function-prefix")
4318 .getValueAsString()
4319 .getAsInteger(10, PatchableFunctionPrefix);
4320 (void)F.getFnAttribute("patchable-function-entry")
4321 .getValueAsString()
4322 .getAsInteger(10, PatchableFunctionEntry);
4323 if (!PatchableFunctionPrefix && !PatchableFunctionEntry)
4324 return;
4325 const unsigned PointerSize = getPointerSize();
4327 auto Flags = ELF::SHF_WRITE | ELF::SHF_ALLOC;
4328 const MCSymbolELF *LinkedToSym = nullptr;
4329 StringRef GroupName;
4330
4331 // GNU as < 2.35 did not support section flag 'o'. GNU ld < 2.36 did not
4332 // support mixed SHF_LINK_ORDER and non-SHF_LINK_ORDER sections.
4333 if (MAI->useIntegratedAssembler() || MAI->binutilsIsAtLeast(2, 36)) {
4334 Flags |= ELF::SHF_LINK_ORDER;
4335 if (F.hasComdat()) {
4336 Flags |= ELF::SHF_GROUP;
4337 GroupName = F.getComdat()->getName();
4338 }
4339 LinkedToSym = cast<MCSymbolELF>(CurrentFnSym);
4340 }
4341 OutStreamer->switchSection(OutContext.getELFSection(
4342 "__patchable_function_entries", ELF::SHT_PROGBITS, Flags, 0, GroupName,
4343 F.hasComdat(), MCSection::NonUniqueID, LinkedToSym));
4344 emitAlignment(Align(PointerSize));
4345 OutStreamer->emitSymbolValue(CurrentPatchableFunctionEntrySym, PointerSize);
4346 }
4347}
4348
4350 return OutStreamer->getContext().getDwarfVersion();
4351}
4352
4354 OutStreamer->getContext().setDwarfVersion(Version);
4355}
4356
4358 return OutStreamer->getContext().getDwarfFormat() == dwarf::DWARF64;
4359}
4360
4363 OutStreamer->getContext().getDwarfFormat());
4364}
4365
4367 return {getDwarfVersion(), uint8_t(MAI->getCodePointerSize()),
4368 OutStreamer->getContext().getDwarfFormat(),
4370}
4371
4374 OutStreamer->getContext().getDwarfFormat());
4375}
4376
4377std::tuple<const MCSymbol *, uint64_t, const MCSymbol *,
4380 const MCSymbol *BranchLabel) const {
4381 const auto TLI = MF->getSubtarget().getTargetLowering();
4382 const auto BaseExpr =
4384 const auto Base = &cast<MCSymbolRefExpr>(BaseExpr)->getSymbol();
4385
4386 // By default, for the architectures that support CodeView,
4387 // EK_LabelDifference32 is implemented as an Int32 from the base address.
4388 return std::make_tuple(Base, 0, BranchLa