1 //===- lib/MC/MCAssembler.cpp - Assembler Backend Implementation ----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #define DEBUG_TYPE "assembler"
11 #include "llvm/MC/MCAssembler.h"
12 #include "llvm/MC/MCAsmLayout.h"
13 #include "llvm/MC/MCCodeEmitter.h"
14 #include "llvm/MC/MCExpr.h"
15 #include "llvm/MC/MCObjectWriter.h"
16 #include "llvm/MC/MCSection.h"
17 #include "llvm/MC/MCSymbol.h"
18 #include "llvm/MC/MCValue.h"
19 #include "llvm/MC/MCDwarf.h"
20 #include "llvm/ADT/OwningPtr.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/ADT/StringExtras.h"
23 #include "llvm/ADT/Twine.h"
24 #include "llvm/Support/Debug.h"
25 #include "llvm/Support/ErrorHandling.h"
26 #include "llvm/Support/raw_ostream.h"
27 #include "llvm/Target/TargetRegistry.h"
28 #include "llvm/Target/TargetAsmBackend.h"
35 STATISTIC(EmittedFragments, "Number of emitted assembler fragments");
36 STATISTIC(EvaluateFixup, "Number of evaluated fixups");
37 STATISTIC(FragmentLayouts, "Number of fragment layouts");
38 STATISTIC(ObjectBytes, "Number of emitted object file bytes");
39 STATISTIC(RelaxationSteps, "Number of assembler layout and relaxation steps");
40 STATISTIC(RelaxedInstructions, "Number of relaxed instructions");
44 // FIXME FIXME FIXME: There are number of places in this file where we convert
45 // what is a 64-bit assembler value used for computation into a value in the
46 // object file, which may truncate it. We should detect that truncation where
47 // invalid and report errors back.
51 MCAsmLayout::MCAsmLayout(MCAssembler &Asm)
52 : Assembler(Asm), LastValidFragment()
54 // Compute the section layout order. Virtual sections must go last.
55 for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it)
56 if (!it->getSection().isVirtualSection())
57 SectionOrder.push_back(&*it);
58 for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it)
59 if (it->getSection().isVirtualSection())
60 SectionOrder.push_back(&*it);
63 bool MCAsmLayout::isFragmentUpToDate(const MCFragment *F) const {
64 const MCSectionData &SD = *F->getParent();
65 const MCFragment *LastValid = LastValidFragment.lookup(&SD);
68 assert(LastValid->getParent() == F->getParent());
69 return F->getLayoutOrder() <= LastValid->getLayoutOrder();
72 void MCAsmLayout::Invalidate(MCFragment *F) {
73 // If this fragment wasn't already up-to-date, we don't need to do anything.
74 if (!isFragmentUpToDate(F))
77 // Otherwise, reset the last valid fragment to the predecessor of the
78 // invalidated fragment.
79 const MCSectionData &SD = *F->getParent();
80 LastValidFragment[&SD] = F->getPrevNode();
83 void MCAsmLayout::EnsureValid(const MCFragment *F) const {
84 MCSectionData &SD = *F->getParent();
86 MCFragment *Cur = LastValidFragment[&SD];
90 Cur = Cur->getNextNode();
92 // Advance the layout position until the fragment is up-to-date.
93 while (!isFragmentUpToDate(F)) {
94 const_cast<MCAsmLayout*>(this)->LayoutFragment(Cur);
95 Cur = Cur->getNextNode();
99 uint64_t MCAsmLayout::getFragmentEffectiveSize(const MCFragment *F) const {
101 assert(F->EffectiveSize != ~UINT64_C(0) && "Address not set!");
102 return F->EffectiveSize;
105 uint64_t MCAsmLayout::getFragmentOffset(const MCFragment *F) const {
107 assert(F->Offset != ~UINT64_C(0) && "Address not set!");
111 uint64_t MCAsmLayout::getSymbolOffset(const MCSymbolData *SD) const {
112 assert(SD->getFragment() && "Invalid getOffset() on undefined symbol!");
113 return getFragmentOffset(SD->getFragment()) + SD->getOffset();
116 uint64_t MCAsmLayout::getSectionAddressSize(const MCSectionData *SD) const {
117 // The size is the last fragment's end offset.
118 const MCFragment &F = SD->getFragmentList().back();
119 return getFragmentOffset(&F) + getFragmentEffectiveSize(&F);
122 uint64_t MCAsmLayout::getSectionFileSize(const MCSectionData *SD) const {
123 // Virtual sections have no file size.
124 if (SD->getSection().isVirtualSection())
127 // Otherwise, the file size is the same as the address space size.
128 return getSectionAddressSize(SD);
133 MCFragment::MCFragment() : Kind(FragmentType(~0)) {
136 MCFragment::~MCFragment() {
139 MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent)
140 : Kind(_Kind), Parent(_Parent), Atom(0), Offset(~UINT64_C(0)),
141 EffectiveSize(~UINT64_C(0))
144 Parent->getFragmentList().push_back(this);
149 MCSectionData::MCSectionData() : Section(0) {}
151 MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A)
152 : Section(&_Section),
153 Ordinal(~UINT32_C(0)),
155 HasInstructions(false)
158 A->getSectionList().push_back(this);
163 MCSymbolData::MCSymbolData() : Symbol(0) {}
165 MCSymbolData::MCSymbolData(const MCSymbol &_Symbol, MCFragment *_Fragment,
166 uint64_t _Offset, MCAssembler *A)
167 : Symbol(&_Symbol), Fragment(_Fragment), Offset(_Offset),
168 IsExternal(false), IsPrivateExtern(false),
169 CommonSize(0), SymbolSize(0), CommonAlign(0),
173 A->getSymbolList().push_back(this);
178 MCAssembler::MCAssembler(MCContext &_Context, TargetAsmBackend &_Backend,
179 MCCodeEmitter &_Emitter, raw_ostream &_OS)
180 : Context(_Context), Backend(_Backend), Emitter(_Emitter),
181 OS(_OS), RelaxAll(false), SubsectionsViaSymbols(false)
185 MCAssembler::~MCAssembler() {
188 bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const {
189 // Non-temporary labels should always be visible to the linker.
190 if (!Symbol.isTemporary())
193 // Absolute temporary labels are never visible.
194 if (!Symbol.isInSection())
197 // Otherwise, check if the section requires symbols even for temporary labels.
198 return getBackend().doesSectionRequireSymbols(Symbol.getSection());
201 const MCSymbolData *MCAssembler::getAtom(const MCSymbolData *SD) const {
202 // Linker visible symbols define atoms.
203 if (isSymbolLinkerVisible(SD->getSymbol()))
206 // Absolute and undefined symbols have no defining atom.
207 if (!SD->getFragment())
210 // Non-linker visible symbols in sections which can't be atomized have no
212 if (!getBackend().isSectionAtomizable(
213 SD->getFragment()->getParent()->getSection()))
216 // Otherwise, return the atom for the containing fragment.
217 return SD->getFragment()->getAtom();
220 bool MCAssembler::EvaluateFixup(const MCObjectWriter &Writer,
221 const MCAsmLayout &Layout,
222 const MCFixup &Fixup, const MCFragment *DF,
223 MCValue &Target, uint64_t &Value) const {
224 ++stats::EvaluateFixup;
226 if (!Fixup.getValue()->EvaluateAsRelocatable(Target, &Layout))
227 report_fatal_error("expected relocatable expression");
229 // FIXME: How do non-scattered symbols work in ELF? I presume the linker
230 // doesn't support small relocations, but then under what criteria does the
231 // assembler allow symbol differences?
233 Value = Target.getConstant();
235 bool IsPCRel = Emitter.getFixupKindInfo(
236 Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel;
237 bool IsResolved = true;
238 if (const MCSymbolRefExpr *A = Target.getSymA()) {
239 const MCSymbol &Sym = A->getSymbol().AliasedSymbol();
241 Value += Layout.getSymbolOffset(&getSymbolData(Sym));
245 if (const MCSymbolRefExpr *B = Target.getSymB()) {
246 const MCSymbol &Sym = B->getSymbol().AliasedSymbol();
248 Value -= Layout.getSymbolOffset(&getSymbolData(Sym));
254 IsResolved = Writer.IsFixupFullyResolved(*this, Target, IsPCRel, DF);
257 bool ShouldAlignPC = Emitter.getFixupKindInfo(
258 Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsAligned;
259 // PC should be aligned to a 4-byte value.
261 Value -= Layout.getFragmentOffset(DF) + (Fixup.getOffset() & ~0x3);
263 Value -= Layout.getFragmentOffset(DF) + Fixup.getOffset();
269 uint64_t MCAssembler::ComputeFragmentSize(const MCFragment &F,
270 uint64_t FragmentOffset) const {
271 switch (F.getKind()) {
272 case MCFragment::FT_Data:
273 return cast<MCDataFragment>(F).getContents().size();
274 case MCFragment::FT_Fill:
275 return cast<MCFillFragment>(F).getSize();
276 case MCFragment::FT_Inst:
277 return cast<MCInstFragment>(F).getInstSize();
279 case MCFragment::FT_LEB:
280 return cast<MCLEBFragment>(F).getContents().size();
282 case MCFragment::FT_Align: {
283 const MCAlignFragment &AF = cast<MCAlignFragment>(F);
285 uint64_t Size = OffsetToAlignment(FragmentOffset, AF.getAlignment());
287 // Honor MaxBytesToEmit.
288 if (Size > AF.getMaxBytesToEmit())
294 case MCFragment::FT_Org:
295 return cast<MCOrgFragment>(F).getSize();
297 case MCFragment::FT_Dwarf:
298 return cast<MCDwarfLineAddrFragment>(F).getContents().size();
301 assert(0 && "invalid fragment kind");
305 void MCAsmLayout::LayoutFragment(MCFragment *F) {
306 MCFragment *Prev = F->getPrevNode();
308 // We should never try to recompute something which is up-to-date.
309 assert(!isFragmentUpToDate(F) && "Attempt to recompute up-to-date fragment!");
310 // We should never try to compute the fragment layout if it's predecessor
312 assert((!Prev || isFragmentUpToDate(Prev)) &&
313 "Attempt to compute fragment before it's predecessor!");
315 ++stats::FragmentLayouts;
317 // Compute fragment offset and size.
320 Offset += Prev->Offset + Prev->EffectiveSize;
323 F->EffectiveSize = getAssembler().ComputeFragmentSize(*F, F->Offset);
324 LastValidFragment[F->getParent()] = F;
327 /// WriteFragmentData - Write the \arg F data to the output file.
328 static void WriteFragmentData(const MCAssembler &Asm, const MCAsmLayout &Layout,
329 const MCFragment &F, MCObjectWriter *OW) {
330 uint64_t Start = OW->getStream().tell();
333 ++stats::EmittedFragments;
335 // FIXME: Embed in fragments instead?
336 uint64_t FragmentSize = Layout.getFragmentEffectiveSize(&F);
337 switch (F.getKind()) {
338 case MCFragment::FT_Align: {
339 MCAlignFragment &AF = cast<MCAlignFragment>(F);
340 uint64_t Count = FragmentSize / AF.getValueSize();
342 assert(AF.getValueSize() && "Invalid virtual align in concrete fragment!");
344 // FIXME: This error shouldn't actually occur (the front end should emit
345 // multiple .align directives to enforce the semantics it wants), but is
346 // severe enough that we want to report it. How to handle this?
347 if (Count * AF.getValueSize() != FragmentSize)
348 report_fatal_error("undefined .align directive, value size '" +
349 Twine(AF.getValueSize()) +
350 "' is not a divisor of padding size '" +
351 Twine(FragmentSize) + "'");
353 // See if we are aligning with nops, and if so do that first to try to fill
354 // the Count bytes. Then if that did not fill any bytes or there are any
355 // bytes left to fill use the the Value and ValueSize to fill the rest.
356 // If we are aligning with nops, ask that target to emit the right data.
357 if (AF.hasEmitNops()) {
358 if (!Asm.getBackend().WriteNopData(Count, OW))
359 report_fatal_error("unable to write nop sequence of " +
360 Twine(Count) + " bytes");
364 // Otherwise, write out in multiples of the value size.
365 for (uint64_t i = 0; i != Count; ++i) {
366 switch (AF.getValueSize()) {
368 assert(0 && "Invalid size!");
369 case 1: OW->Write8 (uint8_t (AF.getValue())); break;
370 case 2: OW->Write16(uint16_t(AF.getValue())); break;
371 case 4: OW->Write32(uint32_t(AF.getValue())); break;
372 case 8: OW->Write64(uint64_t(AF.getValue())); break;
378 case MCFragment::FT_Data: {
379 MCDataFragment &DF = cast<MCDataFragment>(F);
380 assert(FragmentSize == DF.getContents().size() && "Invalid size!");
381 OW->WriteBytes(DF.getContents().str());
385 case MCFragment::FT_Fill: {
386 MCFillFragment &FF = cast<MCFillFragment>(F);
388 assert(FF.getValueSize() && "Invalid virtual align in concrete fragment!");
390 for (uint64_t i = 0, e = FF.getSize() / FF.getValueSize(); i != e; ++i) {
391 switch (FF.getValueSize()) {
393 assert(0 && "Invalid size!");
394 case 1: OW->Write8 (uint8_t (FF.getValue())); break;
395 case 2: OW->Write16(uint16_t(FF.getValue())); break;
396 case 4: OW->Write32(uint32_t(FF.getValue())); break;
397 case 8: OW->Write64(uint64_t(FF.getValue())); break;
403 case MCFragment::FT_Inst: {
404 MCInstFragment &IF = cast<MCInstFragment>(F);
405 OW->WriteBytes(StringRef(IF.getCode().begin(), IF.getCode().size()));
409 case MCFragment::FT_LEB: {
410 MCLEBFragment &LF = cast<MCLEBFragment>(F);
411 OW->WriteBytes(LF.getContents().str());
415 case MCFragment::FT_Org: {
416 MCOrgFragment &OF = cast<MCOrgFragment>(F);
418 for (uint64_t i = 0, e = FragmentSize; i != e; ++i)
419 OW->Write8(uint8_t(OF.getValue()));
424 case MCFragment::FT_Dwarf: {
425 const MCDwarfLineAddrFragment &OF = cast<MCDwarfLineAddrFragment>(F);
426 OW->WriteBytes(OF.getContents().str());
431 assert(OW->getStream().tell() - Start == FragmentSize);
434 void MCAssembler::WriteSectionData(const MCSectionData *SD,
435 const MCAsmLayout &Layout,
436 MCObjectWriter *OW) const {
437 // Ignore virtual sections.
438 if (SD->getSection().isVirtualSection()) {
439 assert(Layout.getSectionFileSize(SD) == 0 && "Invalid size for section!");
441 // Check that contents are only things legal inside a virtual section.
442 for (MCSectionData::const_iterator it = SD->begin(),
443 ie = SD->end(); it != ie; ++it) {
444 switch (it->getKind()) {
446 assert(0 && "Invalid fragment in virtual section!");
447 case MCFragment::FT_Data: {
448 // Check that we aren't trying to write a non-zero contents (or fixups)
449 // into a virtual section. This is to support clients which use standard
450 // directives to fill the contents of virtual sections.
451 MCDataFragment &DF = cast<MCDataFragment>(*it);
452 assert(DF.fixup_begin() == DF.fixup_end() &&
453 "Cannot have fixups in virtual section!");
454 for (unsigned i = 0, e = DF.getContents().size(); i != e; ++i)
455 assert(DF.getContents()[i] == 0 &&
456 "Invalid data value for virtual section!");
459 case MCFragment::FT_Align:
460 // Check that we aren't trying to write a non-zero value into a virtual
462 assert((!cast<MCAlignFragment>(it)->getValueSize() ||
463 !cast<MCAlignFragment>(it)->getValue()) &&
464 "Invalid align in virtual section!");
466 case MCFragment::FT_Fill:
467 assert(!cast<MCFillFragment>(it)->getValueSize() &&
468 "Invalid fill in virtual section!");
476 uint64_t Start = OW->getStream().tell();
479 for (MCSectionData::const_iterator it = SD->begin(),
480 ie = SD->end(); it != ie; ++it)
481 WriteFragmentData(*this, Layout, *it, OW);
483 assert(OW->getStream().tell() - Start == Layout.getSectionAddressSize(SD));
487 uint64_t MCAssembler::HandleFixup(MCObjectWriter &Writer,
488 const MCAsmLayout &Layout,
490 const MCFixup &Fixup) {
491 // Evaluate the fixup.
494 if (!EvaluateFixup(Writer, Layout, Fixup, &F, Target, FixedValue)) {
495 // The fixup was unresolved, we need a relocation. Inform the object
496 // writer of the relocation, and give it an opportunity to adjust the
497 // fixup value if need be.
498 Writer.RecordRelocation(*this, Layout, &F, Fixup, Target, FixedValue);
503 void MCAssembler::Finish(MCObjectWriter *Writer) {
504 DEBUG_WITH_TYPE("mc-dump", {
505 llvm::errs() << "assembler backend - pre-layout\n--\n";
508 // Create the layout object.
509 MCAsmLayout Layout(*this);
513 // Create dummy fragments and assign section ordinals.
514 unsigned SectionIndex = 0;
515 for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) {
516 // Create dummy fragments to eliminate any empty sections, this simplifies
518 if (it->getFragmentList().empty())
519 new MCDataFragment(it);
521 it->setOrdinal(SectionIndex++);
524 // Assign layout order indices to sections and fragments.
525 for (unsigned i = 0, e = Layout.getSectionOrder().size(); i != e; ++i) {
526 MCSectionData *SD = Layout.getSectionOrder()[i];
527 SD->setLayoutOrder(i);
529 unsigned FragmentIndex = 0;
530 for (MCSectionData::iterator it2 = SD->begin(),
531 ie2 = SD->end(); it2 != ie2; ++it2)
532 it2->setLayoutOrder(FragmentIndex++);
535 llvm::OwningPtr<MCObjectWriter> OwnWriter(0);
537 //no custom Writer_ : create the default one life-managed by OwningPtr
538 OwnWriter.reset(getBackend().createObjectWriter(OS));
539 Writer = OwnWriter.get();
541 report_fatal_error("unable to create object writer!");
544 // Layout until everything fits.
545 while (LayoutOnce(*Writer, Layout))
548 DEBUG_WITH_TYPE("mc-dump", {
549 llvm::errs() << "assembler backend - post-relaxation\n--\n";
552 // Finalize the layout, including fragment lowering.
553 FinishLayout(Layout);
555 DEBUG_WITH_TYPE("mc-dump", {
556 llvm::errs() << "assembler backend - final-layout\n--\n";
559 uint64_t StartOffset = OS.tell();
561 // Allow the object writer a chance to perform post-layout binding (for
562 // example, to set the index fields in the symbol data).
563 Writer->ExecutePostLayoutBinding(*this, Layout);
565 // Evaluate and apply the fixups, generating relocation entries as necessary.
566 for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) {
567 for (MCSectionData::iterator it2 = it->begin(),
568 ie2 = it->end(); it2 != ie2; ++it2) {
569 MCDataFragment *DF = dyn_cast<MCDataFragment>(it2);
571 for (MCDataFragment::fixup_iterator it3 = DF->fixup_begin(),
572 ie3 = DF->fixup_end(); it3 != ie3; ++it3) {
573 MCFixup &Fixup = *it3;
574 uint64_t FixedValue = HandleFixup(*Writer, Layout, *DF, Fixup);
575 getBackend().ApplyFixup(Fixup, DF->getContents().data(),
576 DF->getContents().size(), FixedValue);
579 MCInstFragment *IF = dyn_cast<MCInstFragment>(it2);
581 for (MCInstFragment::fixup_iterator it3 = IF->fixup_begin(),
582 ie3 = IF->fixup_end(); it3 != ie3; ++it3) {
583 MCFixup &Fixup = *it3;
584 uint64_t FixedValue = HandleFixup(*Writer, Layout, *IF, Fixup);
585 getBackend().ApplyFixup(Fixup, IF->getCode().data(),
586 IF->getCode().size(), FixedValue);
592 // Write the object file.
593 Writer->WriteObject(*this, Layout);
595 stats::ObjectBytes += OS.tell() - StartOffset;
598 bool MCAssembler::FixupNeedsRelaxation(const MCObjectWriter &Writer,
599 const MCFixup &Fixup,
600 const MCFragment *DF,
601 const MCAsmLayout &Layout) const {
605 // If we cannot resolve the fixup value, it requires relaxation.
608 if (!EvaluateFixup(Writer, Layout, Fixup, DF, Target, Value))
611 // Otherwise, relax if the value is too big for a (signed) i8.
613 // FIXME: This is target dependent!
614 return int64_t(Value) != int64_t(int8_t(Value));
617 bool MCAssembler::FragmentNeedsRelaxation(const MCObjectWriter &Writer,
618 const MCInstFragment *IF,
619 const MCAsmLayout &Layout) const {
620 // If this inst doesn't ever need relaxation, ignore it. This occurs when we
621 // are intentionally pushing out inst fragments, or because we relaxed a
622 // previous instruction to one that doesn't need relaxation.
623 if (!getBackend().MayNeedRelaxation(IF->getInst()))
626 for (MCInstFragment::const_fixup_iterator it = IF->fixup_begin(),
627 ie = IF->fixup_end(); it != ie; ++it)
628 if (FixupNeedsRelaxation(Writer, *it, IF, Layout))
634 bool MCAssembler::RelaxInstruction(const MCObjectWriter &Writer,
636 MCInstFragment &IF) {
637 if (!FragmentNeedsRelaxation(Writer, &IF, Layout))
640 ++stats::RelaxedInstructions;
642 // FIXME-PERF: We could immediately lower out instructions if we can tell
643 // they are fully resolved, to avoid retesting on later passes.
645 // Relax the fragment.
648 getBackend().RelaxInstruction(IF.getInst(), Relaxed);
650 // Encode the new instruction.
652 // FIXME-PERF: If it matters, we could let the target do this. It can
653 // probably do so more efficiently in many cases.
654 SmallVector<MCFixup, 4> Fixups;
655 SmallString<256> Code;
656 raw_svector_ostream VecOS(Code);
657 getEmitter().EncodeInstruction(Relaxed, VecOS, Fixups);
660 // Update the instruction fragment.
663 IF.getFixups().clear();
664 // FIXME: Eliminate copy.
665 for (unsigned i = 0, e = Fixups.size(); i != e; ++i)
666 IF.getFixups().push_back(Fixups[i]);
671 bool MCAssembler::RelaxOrg(const MCObjectWriter &Writer,
674 int64_t TargetLocation;
675 if (!OF.getOffset().EvaluateAsAbsolute(TargetLocation, Layout))
676 report_fatal_error("expected assembly-time absolute expression");
678 // FIXME: We need a way to communicate this error.
679 uint64_t FragmentOffset = Layout.getFragmentOffset(&OF);
680 int64_t Offset = TargetLocation - FragmentOffset;
681 if (Offset < 0 || Offset >= 0x40000000)
682 report_fatal_error("invalid .org offset '" + Twine(TargetLocation) +
683 "' (at offset '" + Twine(FragmentOffset) + "')");
685 unsigned OldSize = OF.getSize();
687 return OldSize != OF.getSize();
690 bool MCAssembler::RelaxLEB(const MCObjectWriter &Writer,
694 uint64_t OldSize = LF.getContents().size();
695 LF.getValue().EvaluateAsAbsolute(Value, Layout);
696 SmallString<8> &Data = LF.getContents();
698 raw_svector_ostream OSE(Data);
700 MCObjectWriter::EncodeSLEB128(Value, OSE);
702 MCObjectWriter::EncodeULEB128(Value, OSE);
704 return OldSize != LF.getContents().size();
707 bool MCAssembler::RelaxDwarfLineAddr(const MCObjectWriter &Writer,
709 MCDwarfLineAddrFragment &DF) {
710 int64_t AddrDelta = 0;
711 uint64_t OldSize = DF.getContents().size();
712 DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, Layout);
714 LineDelta = DF.getLineDelta();
715 SmallString<8> &Data = DF.getContents();
717 raw_svector_ostream OSE(Data);
718 MCDwarfLineAddr::Encode(LineDelta, AddrDelta, OSE);
720 return OldSize != Data.size();
723 bool MCAssembler::LayoutOnce(const MCObjectWriter &Writer,
724 MCAsmLayout &Layout) {
725 ++stats::RelaxationSteps;
727 // Scan for fragments that need relaxation.
728 bool WasRelaxed = false;
729 for (iterator it = begin(), ie = end(); it != ie; ++it) {
730 MCSectionData &SD = *it;
732 for (MCSectionData::iterator it2 = SD.begin(),
733 ie2 = SD.end(); it2 != ie2; ++it2) {
734 // Check if this is an fragment that needs relaxation.
735 bool relaxedFrag = false;
736 switch(it2->getKind()) {
739 case MCFragment::FT_Inst:
740 relaxedFrag = RelaxInstruction(Writer, Layout,
741 *cast<MCInstFragment>(it2));
743 case MCFragment::FT_Org:
744 relaxedFrag = RelaxOrg(Writer, Layout, *cast<MCOrgFragment>(it2));
746 case MCFragment::FT_Dwarf:
747 relaxedFrag = RelaxDwarfLineAddr(Writer, Layout,
748 *cast<MCDwarfLineAddrFragment>(it2));
750 case MCFragment::FT_LEB:
751 relaxedFrag = RelaxLEB(Writer, Layout, *cast<MCLEBFragment>(it2));
754 // Update the layout, and remember that we relaxed.
756 Layout.Invalidate(it2);
757 WasRelaxed |= relaxedFrag;
764 void MCAssembler::FinishLayout(MCAsmLayout &Layout) {
765 // The layout is done. Mark every fragment as valid.
766 for (unsigned int i = 0, n = Layout.getSectionOrder().size(); i != n; ++i) {
767 Layout.getFragmentOffset(&*Layout.getSectionOrder()[i]->rbegin());
775 raw_ostream &operator<<(raw_ostream &OS, const MCFixup &AF) {
776 OS << "<MCFixup" << " Offset:" << AF.getOffset()
777 << " Value:" << *AF.getValue()
778 << " Kind:" << AF.getKind() << ">";
784 void MCFragment::dump() {
785 raw_ostream &OS = llvm::errs();
789 case MCFragment::FT_Align: OS << "MCAlignFragment"; break;
790 case MCFragment::FT_Data: OS << "MCDataFragment"; break;
791 case MCFragment::FT_Fill: OS << "MCFillFragment"; break;
792 case MCFragment::FT_Inst: OS << "MCInstFragment"; break;
793 case MCFragment::FT_Org: OS << "MCOrgFragment"; break;
794 case MCFragment::FT_Dwarf: OS << "MCDwarfFragment"; break;
795 case MCFragment::FT_LEB: OS << "MCLEBFragment"; break;
798 OS << "<MCFragment " << (void*) this << " LayoutOrder:" << LayoutOrder
799 << " Offset:" << Offset << " EffectiveSize:" << EffectiveSize << ">";
802 case MCFragment::FT_Align: {
803 const MCAlignFragment *AF = cast<MCAlignFragment>(this);
804 if (AF->hasEmitNops())
805 OS << " (emit nops)";
807 OS << " Alignment:" << AF->getAlignment()
808 << " Value:" << AF->getValue() << " ValueSize:" << AF->getValueSize()
809 << " MaxBytesToEmit:" << AF->getMaxBytesToEmit() << ">";
812 case MCFragment::FT_Data: {
813 const MCDataFragment *DF = cast<MCDataFragment>(this);
816 const SmallVectorImpl<char> &Contents = DF->getContents();
817 for (unsigned i = 0, e = Contents.size(); i != e; ++i) {
819 OS << hexdigit((Contents[i] >> 4) & 0xF) << hexdigit(Contents[i] & 0xF);
821 OS << "] (" << Contents.size() << " bytes)";
823 if (!DF->getFixups().empty()) {
826 for (MCDataFragment::const_fixup_iterator it = DF->fixup_begin(),
827 ie = DF->fixup_end(); it != ie; ++it) {
828 if (it != DF->fixup_begin()) OS << ",\n ";
835 case MCFragment::FT_Fill: {
836 const MCFillFragment *FF = cast<MCFillFragment>(this);
837 OS << " Value:" << FF->getValue() << " ValueSize:" << FF->getValueSize()
838 << " Size:" << FF->getSize();
841 case MCFragment::FT_Inst: {
842 const MCInstFragment *IF = cast<MCInstFragment>(this);
845 IF->getInst().dump_pretty(OS);
848 case MCFragment::FT_Org: {
849 const MCOrgFragment *OF = cast<MCOrgFragment>(this);
851 OS << " Offset:" << OF->getOffset() << " Value:" << OF->getValue();
854 case MCFragment::FT_Dwarf: {
855 const MCDwarfLineAddrFragment *OF = cast<MCDwarfLineAddrFragment>(this);
857 OS << " AddrDelta:" << OF->getAddrDelta()
858 << " LineDelta:" << OF->getLineDelta();
861 case MCFragment::FT_LEB: {
862 const MCLEBFragment *LF = cast<MCLEBFragment>(this);
864 OS << " Value:" << LF->getValue() << " Signed:" << LF->isSigned();
871 void MCSectionData::dump() {
872 raw_ostream &OS = llvm::errs();
874 OS << "<MCSectionData";
875 OS << " Alignment:" << getAlignment() << " Fragments:[\n ";
876 for (iterator it = begin(), ie = end(); it != ie; ++it) {
877 if (it != begin()) OS << ",\n ";
883 void MCSymbolData::dump() {
884 raw_ostream &OS = llvm::errs();
886 OS << "<MCSymbolData Symbol:" << getSymbol()
887 << " Fragment:" << getFragment() << " Offset:" << getOffset()
888 << " Flags:" << getFlags() << " Index:" << getIndex();
890 OS << " (common, size:" << getCommonSize()
891 << " align: " << getCommonAlignment() << ")";
894 if (isPrivateExtern())
895 OS << " (private extern)";
899 void MCAssembler::dump() {
900 raw_ostream &OS = llvm::errs();
902 OS << "<MCAssembler\n";
903 OS << " Sections:[\n ";
904 for (iterator it = begin(), ie = end(); it != ie; ++it) {
905 if (it != begin()) OS << ",\n ";
911 for (symbol_iterator it = symbol_begin(), ie = symbol_end(); it != ie; ++it) {
912 if (it != symbol_begin()) OS << ",\n ";