#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Twine.h"
+#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Support/Debug.h"
#include "llvm/Target/TargetRegistry.h"
#include "llvm/Target/TargetAsmBackend.h"
namespace {
namespace stats {
-STATISTIC(RelaxedInstructions, "Number of relaxed instructions");
-STATISTIC(RelaxationSteps, "Number of assembler layout and relaxation steps");
STATISTIC(EmittedFragments, "Number of emitted assembler fragments");
STATISTIC(EvaluateFixup, "Number of evaluated fixups");
+STATISTIC(FragmentLayouts, "Number of fragment layouts");
STATISTIC(ObjectBytes, "Number of emitted object file bytes");
+STATISTIC(RelaxationSteps, "Number of assembler layout and relaxation steps");
+STATISTIC(RelaxedInstructions, "Number of relaxed instructions");
+STATISTIC(SectionLayouts, "Number of section layouts");
}
}
/* *** */
+MCAsmLayout::MCAsmLayout(MCAssembler &Asm)
+ : Assembler(Asm), LastValidFragment(0)
+ {
+ // Compute the section layout order. Virtual sections must go last.
+ for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it)
+ if (!Asm.getBackend().isVirtualSection(it->getSection()))
+ SectionOrder.push_back(&*it);
+ for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it)
+ if (Asm.getBackend().isVirtualSection(it->getSection()))
+ SectionOrder.push_back(&*it);
+}
+
+bool MCAsmLayout::isSectionUpToDate(const MCSectionData *SD) const {
+ // The first section is always up-to-date.
+ unsigned Index = SD->getLayoutOrder();
+ if (!Index)
+ return true;
+
+ // Otherwise, sections are always implicitly computed when the preceeding
+ // fragment is layed out.
+ const MCSectionData *Prev = getSectionOrder()[Index - 1];
+ return isFragmentUpToDate(&(Prev->getFragmentList().back()));
+}
+
+bool MCAsmLayout::isFragmentUpToDate(const MCFragment *F) const {
+ return (LastValidFragment &&
+ F->getLayoutOrder() <= LastValidFragment->getLayoutOrder());
+}
+
+void MCAsmLayout::UpdateForSlide(MCFragment *F, int SlideAmount) {
+ // If this fragment wasn't already up-to-date, we don't need to do anything.
+ if (!isFragmentUpToDate(F))
+ return;
+
+ // Otherwise, reset the last valid fragment to the predecessor of the
+ // invalidated fragment.
+ LastValidFragment = F->getPrevNode();
+ if (!LastValidFragment) {
+ unsigned Index = F->getParent()->getLayoutOrder();
+ if (Index != 0) {
+ MCSectionData *Prev = getSectionOrder()[Index - 1];
+ LastValidFragment = &(Prev->getFragmentList().back());
+ }
+ }
+}
+
+void MCAsmLayout::EnsureValid(const MCFragment *F) const {
+ // Advance the layout position until the fragment is up-to-date.
+ while (!isFragmentUpToDate(F)) {
+ // Advance to the next fragment.
+ MCFragment *Cur = LastValidFragment;
+ if (Cur)
+ Cur = Cur->getNextNode();
+ if (!Cur) {
+ unsigned NextIndex = 0;
+ if (LastValidFragment)
+ NextIndex = LastValidFragment->getParent()->getLayoutOrder() + 1;
+ Cur = SectionOrder[NextIndex]->begin();
+ }
+
+ const_cast<MCAsmLayout*>(this)->LayoutFragment(Cur);
+ }
+}
+
+void MCAsmLayout::FragmentReplaced(MCFragment *Src, MCFragment *Dst) {
+ if (LastValidFragment == Src)
+ LastValidFragment = Dst;
+
+ Dst->Offset = Src->Offset;
+ Dst->EffectiveSize = Src->EffectiveSize;
+}
+
uint64_t MCAsmLayout::getFragmentAddress(const MCFragment *F) const {
assert(F->getParent() && "Missing section()!");
return getSectionAddress(F->getParent()) + getFragmentOffset(F);
}
uint64_t MCAsmLayout::getFragmentEffectiveSize(const MCFragment *F) const {
+ EnsureValid(F);
assert(F->EffectiveSize != ~UINT64_C(0) && "Address not set!");
return F->EffectiveSize;
}
-void MCAsmLayout::setFragmentEffectiveSize(MCFragment *F, uint64_t Value) {
- F->EffectiveSize = Value;
-}
-
uint64_t MCAsmLayout::getFragmentOffset(const MCFragment *F) const {
+ EnsureValid(F);
assert(F->Offset != ~UINT64_C(0) && "Address not set!");
return F->Offset;
}
-void MCAsmLayout::setFragmentOffset(MCFragment *F, uint64_t Value) {
- F->Offset = Value;
-}
-
uint64_t MCAsmLayout::getSymbolAddress(const MCSymbolData *SD) const {
assert(SD->getFragment() && "Invalid getAddress() on undefined symbol!");
return getFragmentAddress(SD->getFragment()) + SD->getOffset();
}
uint64_t MCAsmLayout::getSectionAddress(const MCSectionData *SD) const {
+ EnsureValid(SD->begin());
assert(SD->Address != ~UINT64_C(0) && "Address not set!");
return SD->Address;
}
-void MCAsmLayout::setSectionAddress(MCSectionData *SD, uint64_t Value) {
- SD->Address = Value;
-}
-
-uint64_t MCAsmLayout::getSectionSize(const MCSectionData *SD) const {
- assert(SD->Size != ~UINT64_C(0) && "File size not set!");
- return SD->Size;
-}
-void MCAsmLayout::setSectionSize(MCSectionData *SD, uint64_t Value) {
- SD->Size = Value;
+uint64_t MCAsmLayout::getSectionAddressSize(const MCSectionData *SD) const {
+ // The size is the last fragment's end offset.
+ const MCFragment &F = SD->getFragmentList().back();
+ return getFragmentOffset(&F) + getFragmentEffectiveSize(&F);
}
uint64_t MCAsmLayout::getSectionFileSize(const MCSectionData *SD) const {
- assert(SD->FileSize != ~UINT64_C(0) && "File size not set!");
- return SD->FileSize;
-}
-void MCAsmLayout::setSectionFileSize(MCSectionData *SD, uint64_t Value) {
- SD->FileSize = Value;
+ // Virtual sections have no file size.
+ if (getAssembler().getBackend().isVirtualSection(SD->getSection()))
+ return 0;
+
+ // Otherwise, the file size is the same as the address space size.
+ return getSectionAddressSize(SD);
}
- /// @}
+uint64_t MCAsmLayout::getSectionSize(const MCSectionData *SD) const {
+ // The logical size is the address space size minus any tail padding.
+ uint64_t Size = getSectionAddressSize(SD);
+ const MCAlignFragment *AF =
+ dyn_cast<MCAlignFragment>(&(SD->getFragmentList().back()));
+ if (AF && AF->hasOnlyAlignAddress())
+ Size -= getFragmentEffectiveSize(AF);
+
+ return Size;
+}
/* *** */
MCFragment::MCFragment() : Kind(FragmentType(~0)) {
}
+MCFragment::~MCFragment() {
+}
+
MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent)
- : Kind(_Kind),
- Parent(_Parent),
+ : Kind(_Kind), Parent(_Parent), Atom(0), Offset(~UINT64_C(0)),
EffectiveSize(~UINT64_C(0))
{
if (Parent)
Parent->getFragmentList().push_back(this);
}
-MCFragment::~MCFragment() {
-}
-
/* *** */
MCSectionData::MCSectionData() : Section(0) {}
: Section(&_Section),
Alignment(1),
Address(~UINT64_C(0)),
- Size(~UINT64_C(0)),
- FileSize(~UINT64_C(0)),
HasInstructions(false)
{
if (A)
uint64_t _Offset, MCAssembler *A)
: Symbol(&_Symbol), Fragment(_Fragment), Offset(_Offset),
IsExternal(false), IsPrivateExtern(false),
- CommonSize(0), CommonAlign(0), Flags(0), Index(0)
+ CommonSize(0), SymbolSize(0), CommonAlign(0),
+ Flags(0), Index(0)
{
if (A)
A->getSymbolList().push_back(this);
MCAssembler::MCAssembler(MCContext &_Context, TargetAsmBackend &_Backend,
MCCodeEmitter &_Emitter, raw_ostream &_OS)
: Context(_Context), Backend(_Backend), Emitter(_Emitter),
- OS(_OS), SubsectionsViaSymbols(false)
+ OS(_OS), RelaxAll(false), SubsectionsViaSymbols(false)
{
}
}
static bool isScatteredFixupFullyResolvedSimple(const MCAssembler &Asm,
- const MCAsmFixup &Fixup,
+ const MCFixup &Fixup,
const MCValue Target,
const MCSection *BaseSection) {
// The effective fixup address is
// resolved. This also works in conjunction with absolutized .set, which
// requires the compiler to use .set to absolutize the differences between
// symbols which the compiler knows to be assembly time constants, so we don't
- // need to worry about consider symbol differences fully resolved.
+ // need to worry about considering symbol differences fully resolved.
// Non-relative fixups are only resolved if constant.
if (!BaseSection)
static bool isScatteredFixupFullyResolved(const MCAssembler &Asm,
const MCAsmLayout &Layout,
- const MCAsmFixup &Fixup,
+ const MCFixup &Fixup,
const MCValue Target,
const MCSymbolData *BaseSymbol) {
// The effective fixup address is
return !B_Base && BaseSymbol == A_Base;
}
-bool MCAssembler::isSymbolLinkerVisible(const MCSymbolData *SD) const {
+bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const {
// Non-temporary labels should always be visible to the linker.
- if (!SD->getSymbol().isTemporary())
+ if (!Symbol.isTemporary())
return true;
// Absolute temporary labels are never visible.
- if (!SD->getFragment())
+ if (!Symbol.isInSection())
return false;
// Otherwise, check if the section requires symbols even for temporary labels.
- return getBackend().doesSectionRequireSymbols(
- SD->getFragment()->getParent()->getSection());
+ return getBackend().doesSectionRequireSymbols(Symbol.getSection());
}
-// FIXME-PERF: This routine is really slow.
-const MCSymbolData *MCAssembler::getAtomForAddress(const MCAsmLayout &Layout,
- const MCSectionData *Section,
- uint64_t Address) const {
- const MCSymbolData *Best = 0;
- uint64_t BestAddress = 0;
-
- for (MCAssembler::const_symbol_iterator it = symbol_begin(),
- ie = symbol_end(); it != ie; ++it) {
- // Ignore non-linker visible symbols.
- if (!isSymbolLinkerVisible(it))
- continue;
-
- // Ignore symbols not in the same section.
- if (!it->getFragment() || it->getFragment()->getParent() != Section)
- continue;
-
- // Otherwise, find the closest symbol preceding this address (ties are
- // resolved in favor of the last defined symbol).
- uint64_t SymbolAddress = Layout.getSymbolAddress(it);
- if (SymbolAddress <= Address && (!Best || SymbolAddress >= BestAddress)) {
- Best = it;
- BestAddress = SymbolAddress;
- }
- }
-
- return Best;
-}
-
-// FIXME-PERF: This routine is really slow.
const MCSymbolData *MCAssembler::getAtom(const MCAsmLayout &Layout,
const MCSymbolData *SD) const {
// Linker visible symbols define atoms.
- if (isSymbolLinkerVisible(SD))
+ if (isSymbolLinkerVisible(SD->getSymbol()))
return SD;
// Absolute and undefined symbols have no defining atom.
if (!SD->getFragment())
return 0;
- // Otherwise, search by address.
- return getAtomForAddress(Layout, SD->getFragment()->getParent(),
- Layout.getSymbolAddress(SD));
+ // Non-linker visible symbols in sections which can't be atomized have no
+ // defining atom.
+ if (!getBackend().isSectionAtomizable(
+ SD->getFragment()->getParent()->getSection()))
+ return 0;
+
+ // Otherwise, return the atom for the containing fragment.
+ return SD->getFragment()->getAtom();
}
bool MCAssembler::EvaluateFixup(const MCAsmLayout &Layout,
- const MCAsmFixup &Fixup, const MCFragment *DF,
+ const MCFixup &Fixup, const MCFragment *DF,
MCValue &Target, uint64_t &Value) const {
++stats::EvaluateFixup;
- if (!Fixup.Value->EvaluateAsRelocatable(Target, &Layout))
- llvm_report_error("expected relocatable expression");
+ if (!Fixup.getValue()->EvaluateAsRelocatable(Target, &Layout))
+ report_fatal_error("expected relocatable expression");
// FIXME: How do non-scattered symbols work in ELF? I presume the linker
// doesn't support small relocations, but then under what criteria does the
Value = Target.getConstant();
- bool IsPCRel =
- Emitter.getFixupKindInfo(Fixup.Kind).Flags & MCFixupKindInfo::FKF_IsPCRel;
+ bool IsPCRel = Emitter.getFixupKindInfo(
+ Fixup.getKind()).Flags & MCFixupKindInfo::FKF_IsPCRel;
bool IsResolved = true;
if (const MCSymbolRefExpr *A = Target.getSymA()) {
if (A->getSymbol().isDefined())
// symbol) that the fixup value is relative to.
const MCSymbolData *BaseSymbol = 0;
if (IsPCRel) {
- BaseSymbol = getAtomForAddress(
- Layout, DF->getParent(), Layout.getFragmentAddress(DF)+Fixup.Offset);
+ BaseSymbol = DF->getAtom();
if (!BaseSymbol)
IsResolved = false;
}
}
if (IsPCRel)
- Value -= Layout.getFragmentAddress(DF) + Fixup.Offset;
+ Value -= Layout.getFragmentAddress(DF) + Fixup.getOffset();
return IsResolved;
}
-void MCAssembler::LayoutSection(MCSectionData &SD,
- MCAsmLayout &Layout) {
- uint64_t Address, StartAddress = Address = Layout.getSectionAddress(&SD);
+uint64_t MCAssembler::ComputeFragmentSize(MCAsmLayout &Layout,
+ const MCFragment &F,
+ uint64_t SectionAddress,
+ uint64_t FragmentOffset) const {
+ switch (F.getKind()) {
+ case MCFragment::FT_Data:
+ return cast<MCDataFragment>(F).getContents().size();
+ case MCFragment::FT_Fill:
+ return cast<MCFillFragment>(F).getSize();
+ case MCFragment::FT_Inst:
+ return cast<MCInstFragment>(F).getInstSize();
- for (MCSectionData::iterator it = SD.begin(), ie = SD.end(); it != ie; ++it) {
- MCFragment &F = *it;
+ case MCFragment::FT_Align: {
+ const MCAlignFragment &AF = cast<MCAlignFragment>(F);
- uint64_t FragmentOffset = Address - StartAddress;
- Layout.setFragmentOffset(&F, FragmentOffset);
+ assert((!AF.hasOnlyAlignAddress() || !AF.getNextNode()) &&
+ "Invalid OnlyAlignAddress bit, not the last fragment!");
- // Evaluate fragment size.
- uint64_t EffectiveSize = 0;
- switch (F.getKind()) {
- case MCFragment::FT_Align: {
- MCAlignFragment &AF = cast<MCAlignFragment>(F);
+ uint64_t Size = OffsetToAlignment(SectionAddress + FragmentOffset,
+ AF.getAlignment());
- EffectiveSize = OffsetToAlignment(Address, AF.getAlignment());
- if (EffectiveSize > AF.getMaxBytesToEmit())
- EffectiveSize = 0;
- break;
- }
+ // Honor MaxBytesToEmit.
+ if (Size > AF.getMaxBytesToEmit())
+ return 0;
- case MCFragment::FT_Data:
- EffectiveSize = cast<MCDataFragment>(F).getContents().size();
- break;
+ return Size;
+ }
- case MCFragment::FT_Fill: {
- MCFillFragment &FF = cast<MCFillFragment>(F);
- EffectiveSize = FF.getValueSize() * FF.getCount();
- break;
- }
+ case MCFragment::FT_Org: {
+ const MCOrgFragment &OF = cast<MCOrgFragment>(F);
- case MCFragment::FT_Inst:
- EffectiveSize = cast<MCInstFragment>(F).getInstSize();
- break;
+ // FIXME: We should compute this sooner, we don't want to recurse here, and
+ // we would like to be more functional.
+ int64_t TargetLocation;
+ if (!OF.getOffset().EvaluateAsAbsolute(TargetLocation, &Layout))
+ report_fatal_error("expected assembly-time absolute expression");
- case MCFragment::FT_Org: {
- MCOrgFragment &OF = cast<MCOrgFragment>(F);
+ // FIXME: We need a way to communicate this error.
+ int64_t Offset = TargetLocation - FragmentOffset;
+ if (Offset < 0 || Offset >= 0x40000000)
+ report_fatal_error("invalid .org offset '" + Twine(TargetLocation) +
+ "' (at offset '" + Twine(FragmentOffset) + "'");
- int64_t TargetLocation;
- if (!OF.getOffset().EvaluateAsAbsolute(TargetLocation, &Layout))
- llvm_report_error("expected assembly-time absolute expression");
+ return Offset;
+ }
+ }
- // FIXME: We need a way to communicate this error.
- int64_t Offset = TargetLocation - FragmentOffset;
- if (Offset < 0)
- llvm_report_error("invalid .org offset '" + Twine(TargetLocation) +
- "' (at offset '" + Twine(FragmentOffset) + "'");
+ assert(0 && "invalid fragment kind");
+ return 0;
+}
- EffectiveSize = Offset;
- break;
- }
+void MCAsmLayout::LayoutFile() {
+ // Initialize the first section and set the valid fragment layout point. All
+ // actual layout computations are done lazily.
+ LastValidFragment = 0;
+ if (!getSectionOrder().empty())
+ getSectionOrder().front()->Address = 0;
+}
- case MCFragment::FT_ZeroFill: {
- MCZeroFillFragment &ZFF = cast<MCZeroFillFragment>(F);
+void MCAsmLayout::LayoutFragment(MCFragment *F) {
+ MCFragment *Prev = F->getPrevNode();
+
+ // We should never try to recompute something which is up-to-date.
+ assert(!isFragmentUpToDate(F) && "Attempt to recompute up-to-date fragment!");
+ // We should never try to compute the fragment layout if the section isn't
+ // up-to-date.
+ assert(isSectionUpToDate(F->getParent()) &&
+ "Attempt to compute fragment before it's section!");
+ // We should never try to compute the fragment layout if it's predecessor
+ // isn't up-to-date.
+ assert((!Prev || isFragmentUpToDate(Prev)) &&
+ "Attempt to compute fragment before it's predecessor!");
+
+ ++stats::FragmentLayouts;
+
+ // Compute the fragment start address.
+ uint64_t StartAddress = F->getParent()->Address;
+ uint64_t Address = StartAddress;
+ if (Prev)
+ Address += Prev->Offset + Prev->EffectiveSize;
+
+ // Compute fragment offset and size.
+ F->Offset = Address - StartAddress;
+ F->EffectiveSize = getAssembler().ComputeFragmentSize(*this, *F, StartAddress,
+ F->Offset);
+ LastValidFragment = F;
+
+ // If this is the last fragment in a section, update the next section address.
+ if (!F->getNextNode()) {
+ unsigned NextIndex = F->getParent()->getLayoutOrder() + 1;
+ if (NextIndex != getSectionOrder().size())
+ LayoutSection(getSectionOrder()[NextIndex]);
+ }
+}
- // Align the fragment offset; it is safe to adjust the offset freely since
- // this is only in virtual sections.
- //
- // FIXME: We shouldn't be doing this here.
- Address = RoundUpToAlignment(Address, ZFF.getAlignment());
- Layout.setFragmentOffset(&F, Address - StartAddress);
+void MCAsmLayout::LayoutSection(MCSectionData *SD) {
+ unsigned SectionOrderIndex = SD->getLayoutOrder();
- EffectiveSize = ZFF.getSize();
- break;
- }
- }
+ ++stats::SectionLayouts;
- Layout.setFragmentEffectiveSize(&F, EffectiveSize);
- Address += EffectiveSize;
+ // Compute the section start address.
+ uint64_t StartAddress = 0;
+ if (SectionOrderIndex) {
+ MCSectionData *Prev = getSectionOrder()[SectionOrderIndex - 1];
+ StartAddress = getSectionAddress(Prev) + getSectionAddressSize(Prev);
}
- // Set the section sizes.
- Layout.setSectionSize(&SD, Address - StartAddress);
- if (getBackend().isVirtualSection(SD.getSection()))
- Layout.setSectionFileSize(&SD, 0);
- else
- Layout.setSectionFileSize(&SD, Address - StartAddress);
+ // Honor the section alignment requirements.
+ StartAddress = RoundUpToAlignment(StartAddress, SD->getAlignment());
+
+ // Set the section address.
+ SD->Address = StartAddress;
}
/// WriteFragmentData - Write the \arg F data to the output file.
MCAlignFragment &AF = cast<MCAlignFragment>(F);
uint64_t Count = FragmentSize / AF.getValueSize();
+ assert(AF.getValueSize() && "Invalid virtual align in concrete fragment!");
+
// FIXME: This error shouldn't actually occur (the front end should emit
// multiple .align directives to enforce the semantics it wants), but is
// severe enough that we want to report it. How to handle this?
if (Count * AF.getValueSize() != FragmentSize)
- llvm_report_error("undefined .align directive, value size '" +
+ report_fatal_error("undefined .align directive, value size '" +
Twine(AF.getValueSize()) +
"' is not a divisor of padding size '" +
Twine(FragmentSize) + "'");
// the Count bytes. Then if that did not fill any bytes or there are any
// bytes left to fill use the the Value and ValueSize to fill the rest.
// If we are aligning with nops, ask that target to emit the right data.
- if (AF.getEmitNops()) {
+ if (AF.hasEmitNops()) {
if (!Asm.getBackend().WriteNopData(Count, OW))
- llvm_report_error("unable to write nop sequence of " +
+ report_fatal_error("unable to write nop sequence of " +
Twine(Count) + " bytes");
break;
}
case MCFragment::FT_Fill: {
MCFillFragment &FF = cast<MCFillFragment>(F);
- for (uint64_t i = 0, e = FF.getCount(); i != e; ++i) {
+
+ assert(FF.getValueSize() && "Invalid virtual align in concrete fragment!");
+
+ for (uint64_t i = 0, e = FF.getSize() / FF.getValueSize(); i != e; ++i) {
switch (FF.getValueSize()) {
default:
assert(0 && "Invalid size!");
break;
}
-
- case MCFragment::FT_ZeroFill: {
- assert(0 && "Invalid zero fill fragment in concrete section!");
- break;
- }
}
assert(OW->getStream().tell() - Start == FragmentSize);
void MCAssembler::WriteSectionData(const MCSectionData *SD,
const MCAsmLayout &Layout,
MCObjectWriter *OW) const {
- uint64_t SectionSize = Layout.getSectionSize(SD);
- uint64_t SectionFileSize = Layout.getSectionFileSize(SD);
-
// Ignore virtual sections.
if (getBackend().isVirtualSection(SD->getSection())) {
- assert(SectionFileSize == 0 && "Invalid size for section!");
+ assert(Layout.getSectionFileSize(SD) == 0 && "Invalid size for section!");
+
+ // Check that contents are only things legal inside a virtual section.
+ for (MCSectionData::const_iterator it = SD->begin(),
+ ie = SD->end(); it != ie; ++it) {
+ switch (it->getKind()) {
+ default:
+ assert(0 && "Invalid fragment in virtual section!");
+ case MCFragment::FT_Data: {
+ // Check that we aren't trying to write a non-zero contents (or fixups)
+ // into a virtual section. This is to support clients which use standard
+ // directives to fill the contents of virtual sections.
+ MCDataFragment &DF = cast<MCDataFragment>(*it);
+ assert(DF.fixup_begin() == DF.fixup_end() &&
+ "Cannot have fixups in virtual section!");
+ for (unsigned i = 0, e = DF.getContents().size(); i != e; ++i)
+ assert(DF.getContents()[i] == 0 &&
+ "Invalid data value for virtual section!");
+ break;
+ }
+ case MCFragment::FT_Align:
+ // Check that we aren't trying to write a non-zero value into a virtual
+ // section.
+ assert((!cast<MCAlignFragment>(it)->getValueSize() ||
+ !cast<MCAlignFragment>(it)->getValue()) &&
+ "Invalid align in virtual section!");
+ break;
+ case MCFragment::FT_Fill:
+ assert(!cast<MCFillFragment>(it)->getValueSize() &&
+ "Invalid fill in virtual section!");
+ break;
+ }
+ }
+
return;
}
ie = SD->end(); it != ie; ++it)
WriteFragmentData(*this, Layout, *it, OW);
- // Add section padding.
- assert(SectionFileSize >= SectionSize && "Invalid section sizes!");
- OW->WriteZeros(SectionFileSize - SectionSize);
+ assert(OW->getStream().tell() - Start == Layout.getSectionFileSize(SD));
+}
+
+void MCAssembler::AddSectionToTheEnd(MCSectionData &SD, MCAsmLayout &Layout) {
+ // Create dummy fragments and assign section ordinals.
+ unsigned SectionIndex = 0;
+ for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it)
+ SectionIndex++;
+
+ SD.setOrdinal(SectionIndex);
+
+ // Assign layout order indices to sections and fragments.
+ unsigned FragmentIndex = 0;
+ unsigned i = 0;
+ for (unsigned e = Layout.getSectionOrder().size(); i != e; ++i) {
+ MCSectionData *SD = Layout.getSectionOrder()[i];
+
+ for (MCSectionData::iterator it2 = SD->begin(),
+ ie2 = SD->end(); it2 != ie2; ++it2)
+ FragmentIndex++;
+ }
+
+ SD.setLayoutOrder(i);
+ for (MCSectionData::iterator it2 = SD.begin(),
+ ie2 = SD.end(); it2 != ie2; ++it2) {
+ it2->setLayoutOrder(FragmentIndex++);
+ }
+ Layout.getSectionOrder().push_back(&SD);
+
+ Layout.LayoutSection(&SD);
+
+ // Layout until everything fits.
+ while (LayoutOnce(Layout))
+ continue;
- assert(OW->getStream().tell() - Start == SectionFileSize);
}
-void MCAssembler::Finish() {
+void MCAssembler::Finish(MCObjectWriter *Writer) {
DEBUG_WITH_TYPE("mc-dump", {
llvm::errs() << "assembler backend - pre-layout\n--\n";
dump(); });
- // Layout until everything fits.
+ // Create the layout object.
MCAsmLayout Layout(*this);
+
+ // Insert additional align fragments for concrete sections to explicitly pad
+ // the previous section to match their alignment requirements. This is for
+ // 'gas' compatibility, it shouldn't strictly be necessary.
+ //
+ // FIXME: This may be Mach-O specific.
+ for (unsigned i = 1, e = Layout.getSectionOrder().size(); i < e; ++i) {
+ MCSectionData *SD = Layout.getSectionOrder()[i];
+
+ // Ignore sections without alignment requirements.
+ unsigned Align = SD->getAlignment();
+ if (Align <= 1)
+ continue;
+
+ // Ignore virtual sections, they don't cause file size modifications.
+ if (getBackend().isVirtualSection(SD->getSection()))
+ continue;
+
+ // Otherwise, create a new align fragment at the end of the previous
+ // section.
+ MCAlignFragment *AF = new MCAlignFragment(Align, 0, 1, Align,
+ Layout.getSectionOrder()[i - 1]);
+ AF->setOnlyAlignAddress(true);
+ }
+
+ // Create dummy fragments and assign section ordinals.
+ unsigned SectionIndex = 0;
+ for (MCAssembler::iterator it = begin(), ie = end(); it != ie; ++it) {
+ // Create dummy fragments to eliminate any empty sections, this simplifies
+ // layout.
+ if (it->getFragmentList().empty())
+ new MCFillFragment(0, 1, 0, it);
+
+ it->setOrdinal(SectionIndex++);
+ }
+
+ // Assign layout order indices to sections and fragments.
+ unsigned FragmentIndex = 0;
+ for (unsigned i = 0, e = Layout.getSectionOrder().size(); i != e; ++i) {
+ MCSectionData *SD = Layout.getSectionOrder()[i];
+ SD->setLayoutOrder(i);
+
+ for (MCSectionData::iterator it2 = SD->begin(),
+ ie2 = SD->end(); it2 != ie2; ++it2)
+ it2->setLayoutOrder(FragmentIndex++);
+ }
+
+ // Layout until everything fits.
while (LayoutOnce(Layout))
continue;
dump(); });
uint64_t StartOffset = OS.tell();
- llvm::OwningPtr<MCObjectWriter> Writer(getBackend().createObjectWriter(OS));
- if (!Writer)
- llvm_report_error("unable to create object writer!");
+
+ llvm::OwningPtr<MCObjectWriter> OwnWriter(0);
+ if (Writer == 0) {
+ //no custom Writer_ : create the default one life-managed by OwningPtr
+ OwnWriter.reset(getBackend().createObjectWriter(OS));
+ Writer = OwnWriter.get();
+ if (!Writer)
+ report_fatal_error("unable to create object writer!");
+ }
// Allow the object writer a chance to perform post-layout binding (for
// example, to set the index fields in the symbol data).
for (MCDataFragment::fixup_iterator it3 = DF->fixup_begin(),
ie3 = DF->fixup_end(); it3 != ie3; ++it3) {
- MCAsmFixup &Fixup = *it3;
+ MCFixup &Fixup = *it3;
// Evaluate the fixup.
MCValue Target;
// Write the object file.
Writer->WriteObject(*this, Layout);
- OS.flush();
stats::ObjectBytes += OS.tell() - StartOffset;
}
-bool MCAssembler::FixupNeedsRelaxation(const MCAsmFixup &Fixup,
+bool MCAssembler::FixupNeedsRelaxation(const MCFixup &Fixup,
const MCFragment *DF,
const MCAsmLayout &Layout) const {
+ if (getRelaxAll())
+ return true;
+
// If we cannot resolve the fixup value, it requires relaxation.
MCValue Target;
uint64_t Value;
return true;
// Otherwise, relax if the value is too big for a (signed) i8.
+ //
+ // FIXME: This is target dependent!
return int64_t(Value) != int64_t(int8_t(Value));
}
// If this inst doesn't ever need relaxation, ignore it. This occurs when we
// are intentionally pushing out inst fragments, or because we relaxed a
// previous instruction to one that doesn't need relaxation.
- if (!getBackend().MayNeedRelaxation(IF->getInst(), IF->getFixups()))
+ if (!getBackend().MayNeedRelaxation(IF->getInst()))
return false;
for (MCInstFragment::const_fixup_iterator it = IF->fixup_begin(),
bool MCAssembler::LayoutOnce(MCAsmLayout &Layout) {
++stats::RelaxationSteps;
- // Layout the concrete sections and fragments.
- uint64_t Address = 0;
- MCSectionData *Prev = 0;
- for (iterator it = begin(), ie = end(); it != ie; ++it) {
- MCSectionData &SD = *it;
-
- // Skip virtual sections.
- if (getBackend().isVirtualSection(SD.getSection()))
- continue;
-
- // Align this section if necessary by adding padding bytes to the previous
- // section.
- if (uint64_t Pad = OffsetToAlignment(Address, it->getAlignment())) {
- assert(Prev && "Missing prev section!");
- Layout.setSectionFileSize(Prev, Layout.getSectionFileSize(Prev) + Pad);
- Address += Pad;
- }
-
- // Layout the section fragments and its size.
- Layout.setSectionAddress(&SD, Address);
- LayoutSection(SD, Layout);
- Address += Layout.getSectionFileSize(&SD);
-
- Prev = &SD;
- }
-
- // Layout the virtual sections.
- for (iterator it = begin(), ie = end(); it != ie; ++it) {
- MCSectionData &SD = *it;
-
- if (!getBackend().isVirtualSection(SD.getSection()))
- continue;
-
- // Align this section if necessary by adding padding bytes to the previous
- // section.
- if (uint64_t Pad = OffsetToAlignment(Address, it->getAlignment()))
- Address += Pad;
-
- Layout.setSectionAddress(&SD, Address);
- LayoutSection(SD, Layout);
- Address += Layout.getSectionSize(&SD);
- }
+ // Layout the sections in order.
+ Layout.LayoutFile();
// Scan for fragments that need relaxation.
+ bool WasRelaxed = false;
for (iterator it = begin(), ie = end(); it != ie; ++it) {
MCSectionData &SD = *it;
// Relax the fragment.
MCInst Relaxed;
- getBackend().RelaxInstruction(IF, Relaxed);
+ getBackend().RelaxInstruction(IF->getInst(), Relaxed);
// Encode the new instruction.
//
VecOS.flush();
// Update the instruction fragment.
+ int SlideAmount = Code.size() - IF->getInstSize();
IF->setInst(Relaxed);
IF->getCode() = Code;
IF->getFixups().clear();
- for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
- MCFixup &F = Fixups[i];
- IF->getFixups().push_back(MCAsmFixup(F.getOffset(), *F.getValue(),
- F.getKind()));
- }
+ // FIXME: Eliminate copy.
+ for (unsigned i = 0, e = Fixups.size(); i != e; ++i)
+ IF->getFixups().push_back(Fixups[i]);
- // Restart layout.
- //
- // FIXME-PERF: This is O(N^2), but will be eliminated once we have a
- // smart MCAsmLayout object.
- return true;
+ // Update the layout, and remember that we relaxed.
+ Layout.UpdateForSlide(IF, SlideAmount);
+ WasRelaxed = true;
}
}
- return false;
+ return WasRelaxed;
}
void MCAssembler::FinishLayout(MCAsmLayout &Layout) {
SD.getFragmentList().insert(it2, DF);
// Update the data fragments layout data.
- //
- // FIXME: Add MCAsmLayout utility for this.
DF->setParent(IF->getParent());
- Layout.setFragmentOffset(DF, Layout.getFragmentOffset(IF));
- Layout.setFragmentEffectiveSize(DF, Layout.getFragmentEffectiveSize(IF));
+ DF->setAtom(IF->getAtom());
+ DF->setLayoutOrder(IF->getLayoutOrder());
+ Layout.FragmentReplaced(IF, DF);
// Copy in the data and the fixups.
DF->getContents().append(IF->getCode().begin(), IF->getCode().end());
namespace llvm {
-raw_ostream &operator<<(raw_ostream &OS, const MCAsmFixup &AF) {
- OS << "<MCAsmFixup" << " Offset:" << AF.Offset << " Value:" << *AF.Value
- << " Kind:" << AF.Kind << ">";
+raw_ostream &operator<<(raw_ostream &OS, const MCFixup &AF) {
+ OS << "<MCFixup" << " Offset:" << AF.getOffset()
+ << " Value:" << *AF.getValue()
+ << " Kind:" << AF.getKind() << ">";
return OS;
}
void MCFragment::dump() {
raw_ostream &OS = llvm::errs();
- OS << "<MCFragment " << (void*) this << " Offset:" << Offset
- << " EffectiveSize:" << EffectiveSize;
-
- OS << ">";
-}
-
-void MCAlignFragment::dump() {
- raw_ostream &OS = llvm::errs();
-
- OS << "<MCAlignFragment ";
- this->MCFragment::dump();
- OS << "\n ";
- OS << " Alignment:" << getAlignment()
- << " Value:" << getValue() << " ValueSize:" << getValueSize()
- << " MaxBytesToEmit:" << getMaxBytesToEmit() << ">";
-}
+ OS << "<";
+ switch (getKind()) {
+ case MCFragment::FT_Align: OS << "MCAlignFragment"; break;
+ case MCFragment::FT_Data: OS << "MCDataFragment"; break;
+ case MCFragment::FT_Fill: OS << "MCFillFragment"; break;
+ case MCFragment::FT_Inst: OS << "MCInstFragment"; break;
+ case MCFragment::FT_Org: OS << "MCOrgFragment"; break;
+ }
-void MCDataFragment::dump() {
- raw_ostream &OS = llvm::errs();
+ OS << "<MCFragment " << (void*) this << " LayoutOrder:" << LayoutOrder
+ << " Offset:" << Offset << " EffectiveSize:" << EffectiveSize << ">";
- OS << "<MCDataFragment ";
- this->MCFragment::dump();
- OS << "\n ";
- OS << " Contents:[";
- for (unsigned i = 0, e = getContents().size(); i != e; ++i) {
- if (i) OS << ",";
- OS << hexdigit((Contents[i] >> 4) & 0xF) << hexdigit(Contents[i] & 0xF);
- }
- OS << "] (" << getContents().size() << " bytes)";
-
- if (!getFixups().empty()) {
- OS << ",\n ";
- OS << " Fixups:[";
- for (fixup_iterator it = fixup_begin(), ie = fixup_end(); it != ie; ++it) {
- if (it != fixup_begin()) OS << ",\n ";
- OS << *it;
+ switch (getKind()) {
+ case MCFragment::FT_Align: {
+ const MCAlignFragment *AF = cast<MCAlignFragment>(this);
+ if (AF->hasEmitNops())
+ OS << " (emit nops)";
+ if (AF->hasOnlyAlignAddress())
+ OS << " (only align section)";
+ OS << "\n ";
+ OS << " Alignment:" << AF->getAlignment()
+ << " Value:" << AF->getValue() << " ValueSize:" << AF->getValueSize()
+ << " MaxBytesToEmit:" << AF->getMaxBytesToEmit() << ">";
+ break;
+ }
+ case MCFragment::FT_Data: {
+ const MCDataFragment *DF = cast<MCDataFragment>(this);
+ OS << "\n ";
+ OS << " Contents:[";
+ const SmallVectorImpl<char> &Contents = DF->getContents();
+ for (unsigned i = 0, e = Contents.size(); i != e; ++i) {
+ if (i) OS << ",";
+ OS << hexdigit((Contents[i] >> 4) & 0xF) << hexdigit(Contents[i] & 0xF);
+ }
+ OS << "] (" << Contents.size() << " bytes)";
+
+ if (!DF->getFixups().empty()) {
+ OS << ",\n ";
+ OS << " Fixups:[";
+ for (MCDataFragment::const_fixup_iterator it = DF->fixup_begin(),
+ ie = DF->fixup_end(); it != ie; ++it) {
+ if (it != DF->fixup_begin()) OS << ",\n ";
+ OS << *it;
+ }
+ OS << "]";
}
- OS << "]";
+ break;
+ }
+ case MCFragment::FT_Fill: {
+ const MCFillFragment *FF = cast<MCFillFragment>(this);
+ OS << " Value:" << FF->getValue() << " ValueSize:" << FF->getValueSize()
+ << " Size:" << FF->getSize();
+ break;
+ }
+ case MCFragment::FT_Inst: {
+ const MCInstFragment *IF = cast<MCInstFragment>(this);
+ OS << "\n ";
+ OS << " Inst:";
+ IF->getInst().dump_pretty(OS);
+ break;
+ }
+ case MCFragment::FT_Org: {
+ const MCOrgFragment *OF = cast<MCOrgFragment>(this);
+ OS << "\n ";
+ OS << " Offset:" << OF->getOffset() << " Value:" << OF->getValue();
+ break;
+ }
}
-
- OS << ">";
-}
-
-void MCFillFragment::dump() {
- raw_ostream &OS = llvm::errs();
-
- OS << "<MCFillFragment ";
- this->MCFragment::dump();
- OS << "\n ";
- OS << " Value:" << getValue() << " ValueSize:" << getValueSize()
- << " Count:" << getCount() << ">";
-}
-
-void MCInstFragment::dump() {
- raw_ostream &OS = llvm::errs();
-
- OS << "<MCInstFragment ";
- this->MCFragment::dump();
- OS << "\n ";
- OS << " Inst:";
- getInst().dump_pretty(OS);
OS << ">";
}
-void MCOrgFragment::dump() {
- raw_ostream &OS = llvm::errs();
-
- OS << "<MCOrgFragment ";
- this->MCFragment::dump();
- OS << "\n ";
- OS << " Offset:" << getOffset() << " Value:" << getValue() << ">";
-}
-
-void MCZeroFillFragment::dump() {
- raw_ostream &OS = llvm::errs();
-
- OS << "<MCZeroFillFragment ";
- this->MCFragment::dump();
- OS << "\n ";
- OS << " Size:" << getSize() << " Alignment:" << getAlignment() << ">";
-}
-
void MCSectionData::dump() {
raw_ostream &OS = llvm::errs();
OS << "<MCSectionData";
OS << " Alignment:" << getAlignment() << " Address:" << Address
- << " Size:" << Size << " FileSize:" << FileSize
<< " Fragments:[\n ";
for (iterator it = begin(), ie = end(); it != ie; ++it) {
if (it != begin()) OS << ",\n ";
projects / oota-llvm.git / blobdiff