//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "assembler"
#include "llvm/MC/MCAssembler.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCFixupKindInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/Support/MemoryBuffer.h"
-#include "llvm/Support/Compression.h"
-#include "llvm/Support/Host.h"
-
+#include <tuple>
using namespace llvm;
+#define DEBUG_TYPE "assembler"
+
namespace {
namespace stats {
STATISTIC(EmittedFragments, "Number of emitted assembler fragments - total");
return F->Offset;
}
-uint64_t MCAsmLayout::getSymbolOffset(const MCSymbolData *SD) const {
+// Simple getSymbolOffset helper for the non-varibale case.
+static bool getLabelOffset(const MCAsmLayout &Layout, const MCSymbolData &SD,
+ bool ReportError, uint64_t &Val) {
+ if (!SD.getFragment()) {
+ if (ReportError)
+ report_fatal_error("unable to evaluate offset to undefined symbol '" +
+ SD.getSymbol().getName() + "'");
+ return false;
+ }
+ Val = Layout.getFragmentOffset(SD.getFragment()) + SD.getOffset();
+ return true;
+}
+
+static bool getSymbolOffsetImpl(const MCAsmLayout &Layout,
+ const MCSymbolData *SD, bool ReportError,
+ uint64_t &Val) {
const MCSymbol &S = SD->getSymbol();
- // If this is a variable, then recursively evaluate now.
- if (S.isVariable()) {
- MCValue Target;
- if (!S.getVariableValue()->EvaluateAsRelocatable(Target, this))
- report_fatal_error("unable to evaluate offset for variable '" +
- S.getName() + "'");
+ if (!S.isVariable())
+ return getLabelOffset(Layout, *SD, ReportError, Val);
- // Verify that any used symbols are defined.
- if (Target.getSymA() && Target.getSymA()->getSymbol().isUndefined())
- report_fatal_error("unable to evaluate offset to undefined symbol '" +
- Target.getSymA()->getSymbol().getName() + "'");
- if (Target.getSymB() && Target.getSymB()->getSymbol().isUndefined())
- report_fatal_error("unable to evaluate offset to undefined symbol '" +
- Target.getSymB()->getSymbol().getName() + "'");
-
- uint64_t Offset = Target.getConstant();
- if (Target.getSymA())
- Offset += getSymbolOffset(&Assembler.getSymbolData(
- Target.getSymA()->getSymbol()));
- if (Target.getSymB())
- Offset -= getSymbolOffset(&Assembler.getSymbolData(
- Target.getSymB()->getSymbol()));
- return Offset;
+ // If SD is a variable, evaluate it.
+ MCValue Target;
+ if (!S.getVariableValue()->EvaluateAsRelocatable(Target, &Layout, nullptr))
+ report_fatal_error("unable to evaluate offset for variable '" +
+ S.getName() + "'");
+
+ uint64_t Offset = Target.getConstant();
+
+ const MCAssembler &Asm = Layout.getAssembler();
+
+ const MCSymbolRefExpr *A = Target.getSymA();
+ if (A) {
+ uint64_t ValA;
+ if (!getLabelOffset(Layout, Asm.getSymbolData(A->getSymbol()), ReportError,
+ ValA))
+ return false;
+ Offset += ValA;
}
- assert(SD->getFragment() && "Invalid getOffset() on undefined symbol!");
- return getFragmentOffset(SD->getFragment()) + SD->getOffset();
+ const MCSymbolRefExpr *B = Target.getSymB();
+ if (B) {
+ uint64_t ValB;
+ if (!getLabelOffset(Layout, Asm.getSymbolData(B->getSymbol()), ReportError,
+ ValB))
+ return false;
+ Offset -= ValB;
+ }
+
+ Val = Offset;
+ return true;
+}
+
+bool MCAsmLayout::getSymbolOffset(const MCSymbolData *SD, uint64_t &Val) const {
+ return getSymbolOffsetImpl(*this, SD, false, Val);
+}
+
+uint64_t MCAsmLayout::getSymbolOffset(const MCSymbolData *SD) const {
+ uint64_t Val;
+ getSymbolOffsetImpl(*this, SD, true, Val);
+ return Val;
+}
+
+const MCSymbol *MCAsmLayout::getBaseSymbol(const MCSymbol &Symbol) const {
+ if (!Symbol.isVariable())
+ return &Symbol;
+
+ const MCExpr *Expr = Symbol.getVariableValue();
+ MCValue Value;
+ if (!Expr->evaluateAsValue(Value, *this))
+ llvm_unreachable("Invalid Expression");
+
+ const MCSymbolRefExpr *RefB = Value.getSymB();
+ if (RefB)
+ Assembler.getContext().FatalError(
+ SMLoc(), Twine("symbol '") + RefB->getSymbol().getName() +
+ "' could not be evaluated in a subtraction expression");
+
+ const MCSymbolRefExpr *A = Value.getSymA();
+ if (!A)
+ return nullptr;
+
+ const MCSymbol &ASym = A->getSymbol();
+ const MCAssembler &Asm = getAssembler();
+ const MCSymbolData &ASD = Asm.getSymbolData(ASym);
+ if (ASD.isCommon()) {
+ // FIXME: we should probably add a SMLoc to MCExpr.
+ Asm.getContext().FatalError(SMLoc(),
+ "Common symbol " + ASym.getName() +
+ " cannot be used in assignment expr");
+ }
+
+ return &ASym;
}
uint64_t MCAsmLayout::getSectionAddressSize(const MCSectionData *SD) const {
MCFragment::~MCFragment() {
}
-MCFragment::MCFragment(FragmentType _Kind, MCSectionData *_Parent)
- : Kind(_Kind), Parent(_Parent), Atom(0), Offset(~UINT64_C(0))
-{
+MCFragment::MCFragment(FragmentType Kind, MCSectionData *Parent)
+ : Kind(Kind), Parent(Parent), Atom(nullptr), Offset(~UINT64_C(0)) {
if (Parent)
Parent->getFragmentList().push_back(this);
}
/* *** */
-const SmallVectorImpl<char> &MCCompressedFragment::getCompressedContents() const {
- assert(getParent()->size() == 1 &&
- "Only compress sections containing a single fragment");
- if (CompressedContents.empty()) {
- std::unique_ptr<MemoryBuffer> CompressedSection;
- zlib::Status Success =
- zlib::compress(StringRef(getContents().data(), getContents().size()),
- CompressedSection);
- (void)Success;
- assert(Success == zlib::StatusOK);
- CompressedContents.push_back('Z');
- CompressedContents.push_back('L');
- CompressedContents.push_back('I');
- CompressedContents.push_back('B');
- uint64_t Size = getContents().size();
- if (sys::IsLittleEndianHost)
- Size = sys::SwapByteOrder(Size);
- CompressedContents.append(reinterpret_cast<char *>(&Size),
- reinterpret_cast<char *>(&Size + 1));
- CompressedContents.append(CompressedSection->getBuffer().begin(),
- CompressedSection->getBuffer().end());
- }
- return CompressedContents;
-}
-
-SmallVectorImpl<char> &MCCompressedFragment::getContents() {
- assert(CompressedContents.empty() &&
- "Fragment contents should not be altered after compression");
- return MCDataFragment::getContents();
-}
-
-/* *** */
-
-MCSectionData::MCSectionData() : Section(0) {}
+MCSectionData::MCSectionData() : Section(nullptr) {}
-MCSectionData::MCSectionData(const MCSection &_Section, MCAssembler *A)
- : Section(&_Section),
- Ordinal(~UINT32_C(0)),
- Alignment(1),
- BundleLockState(NotBundleLocked), BundleGroupBeforeFirstInst(false),
- HasInstructions(false)
-{
+MCSectionData::MCSectionData(const MCSection &Section, MCAssembler *A)
+ : Section(&Section), Ordinal(~UINT32_C(0)), Alignment(1),
+ BundleLockState(NotBundleLocked), BundleLockNestingDepth(0),
+ BundleGroupBeforeFirstInst(false), HasInstructions(false) {
if (A)
A->getSectionList().push_back(this);
}
SmallVectorImpl<std::pair<unsigned, MCFragment *> >::iterator MI =
std::lower_bound(SubsectionFragmentMap.begin(), SubsectionFragmentMap.end(),
- std::make_pair(Subsection, (MCFragment *)0));
+ std::make_pair(Subsection, (MCFragment *)nullptr));
bool ExactMatch = false;
if (MI != SubsectionFragmentMap.end()) {
ExactMatch = MI->first == Subsection;
return IP;
}
+void MCSectionData::setBundleLockState(BundleLockStateType NewState) {
+ if (NewState == NotBundleLocked) {
+ if (BundleLockNestingDepth == 0) {
+ report_fatal_error("Mismatched bundle_lock/unlock directives");
+ }
+ if (--BundleLockNestingDepth == 0) {
+ BundleLockState = NotBundleLocked;
+ }
+ return;
+ }
+
+ // If any of the directives is an align_to_end directive, the whole nested
+ // group is align_to_end. So don't downgrade from align_to_end to just locked.
+ if (BundleLockState != BundleLockedAlignToEnd) {
+ BundleLockState = NewState;
+ }
+ ++BundleLockNestingDepth;
+}
+
/* *** */
-MCSymbolData::MCSymbolData() : Symbol(0) {}
+MCSymbolData::MCSymbolData() : Symbol(nullptr) {}
-MCSymbolData::MCSymbolData(const MCSymbol &_Symbol, MCFragment *_Fragment,
- uint64_t _Offset, MCAssembler *A)
- : Symbol(&_Symbol), Fragment(_Fragment), Offset(_Offset),
- IsExternal(false), IsPrivateExtern(false),
- CommonSize(0), SymbolSize(0), CommonAlign(0),
- Flags(0), Index(0)
-{
+MCSymbolData::MCSymbolData(const MCSymbol &Symbol, MCFragment *Fragment,
+ uint64_t Offset, MCAssembler *A)
+ : Symbol(&Symbol), Fragment(Fragment), Offset(Offset), SymbolSize(nullptr),
+ CommonAlign(-1U), Flags(0), Index(0) {
if (A)
A->getSymbolList().push_back(this);
}
MCAssembler::MCAssembler(MCContext &Context_, MCAsmBackend &Backend_,
MCCodeEmitter &Emitter_, MCObjectWriter &Writer_,
raw_ostream &OS_)
- : Context(Context_), Backend(Backend_), Emitter(Emitter_), Writer(Writer_),
- OS(OS_), BundleAlignSize(0), RelaxAll(false), NoExecStack(false),
- SubsectionsViaSymbols(false), ELFHeaderEFlags(0) {
+ : Context(Context_), Backend(Backend_), Emitter(Emitter_), Writer(Writer_),
+ OS(OS_), BundleAlignSize(0), RelaxAll(false),
+ SubsectionsViaSymbols(false), ELFHeaderEFlags(0) {
VersionMinInfo.Major = 0; // Major version == 0 for "none specified"
}
SymbolMap.clear();
IndirectSymbols.clear();
DataRegions.clear();
+ LinkerOptions.clear();
+ FileNames.clear();
ThumbFuncs.clear();
+ BundleAlignSize = 0;
RelaxAll = false;
- NoExecStack = false;
SubsectionsViaSymbols = false;
ELFHeaderEFlags = 0;
+ LOHContainer.reset();
+ VersionMinInfo.Major = 0;
// reset objects owned by us
getBackend().reset();
getEmitter().reset();
getWriter().reset();
+ getLOHContainer().reset();
+}
+
+bool MCAssembler::isThumbFunc(const MCSymbol *Symbol) const {
+ if (ThumbFuncs.count(Symbol))
+ return true;
+
+ if (!Symbol->isVariable())
+ return false;
+
+ // FIXME: It looks like gas supports some cases of the form "foo + 2". It
+ // is not clear if that is a bug or a feature.
+ const MCExpr *Expr = Symbol->getVariableValue();
+ const MCSymbolRefExpr *Ref = dyn_cast<MCSymbolRefExpr>(Expr);
+ if (!Ref)
+ return false;
+
+ if (Ref->getKind() != MCSymbolRefExpr::VK_None)
+ return false;
+
+ const MCSymbol &Sym = Ref->getSymbol();
+ if (!isThumbFunc(&Sym))
+ return false;
+
+ ThumbFuncs.insert(Symbol); // Cache it.
+ return true;
+}
+
+void MCAssembler::addLocalUsedInReloc(const MCSymbol &Sym) {
+ assert(Sym.isTemporary());
+ LocalsUsedInReloc.insert(&Sym);
+}
+
+bool MCAssembler::isLocalUsedInReloc(const MCSymbol &Sym) const {
+ assert(Sym.isTemporary());
+ return LocalsUsedInReloc.count(&Sym);
}
bool MCAssembler::isSymbolLinkerVisible(const MCSymbol &Symbol) const {
if (!Symbol.isInSection())
return false;
- // Otherwise, check if the section requires symbols even for temporary labels.
- return getBackend().doesSectionRequireSymbols(Symbol.getSection());
+ if (isLocalUsedInReloc(Symbol))
+ return true;
+
+ return false;
}
const MCSymbolData *MCAssembler::getAtom(const MCSymbolData *SD) const {
// Absolute and undefined symbols have no defining atom.
if (!SD->getFragment())
- return 0;
+ return nullptr;
// Non-linker visible symbols in sections which can't be atomized have no
// defining atom.
- if (!getBackend().isSectionAtomizable(
- SD->getFragment()->getParent()->getSection()))
- return 0;
+ if (!getContext().getAsmInfo()->isSectionAtomizableBySymbols(
+ SD->getFragment()->getParent()->getSection()))
+ return nullptr;
// Otherwise, return the atom for the containing fragment.
return SD->getFragment()->getAtom();
MCValue &Target, uint64_t &Value) const {
++stats::evaluateFixup;
- if (!Fixup.getValue()->EvaluateAsRelocatable(Target, &Layout))
+ // FIXME: This code has some duplication with RecordRelocation. We should
+ // probably merge the two into a single callback that tries to evaluate a
+ // fixup and records a relocation if one is needed.
+ const MCExpr *Expr = Fixup.getValue();
+ if (!Expr->EvaluateAsRelocatable(Target, &Layout, &Fixup))
getContext().FatalError(Fixup.getLoc(), "expected relocatable expression");
bool IsPCRel = Backend.getFixupKindInfo(
} else {
const MCSymbolRefExpr *A = Target.getSymA();
const MCSymbol &SA = A->getSymbol();
- if (A->getKind() != MCSymbolRefExpr::VK_None ||
- SA.AliasedSymbol().isUndefined()) {
+ if (A->getKind() != MCSymbolRefExpr::VK_None || SA.isUndefined()) {
IsResolved = false;
} else {
const MCSymbolData &DataA = getSymbolData(SA);
- IsResolved =
- getWriter().IsSymbolRefDifferenceFullyResolvedImpl(*this, DataA,
- *DF, false, true);
+ IsResolved = getWriter().IsSymbolRefDifferenceFullyResolvedImpl(
+ *this, DataA, nullptr, *DF, false, true);
}
}
} else {
Value = Target.getConstant();
if (const MCSymbolRefExpr *A = Target.getSymA()) {
- const MCSymbol &Sym = A->getSymbol().AliasedSymbol();
+ const MCSymbol &Sym = A->getSymbol();
if (Sym.isDefined())
Value += Layout.getSymbolOffset(&getSymbolData(Sym));
}
if (const MCSymbolRefExpr *B = Target.getSymB()) {
- const MCSymbol &Sym = B->getSymbol().AliasedSymbol();
+ const MCSymbol &Sym = B->getSymbol();
if (Sym.isDefined())
Value -= Layout.getSymbolOffset(&getSymbolData(Sym));
}
case MCFragment::FT_Relaxable:
case MCFragment::FT_CompactEncodedInst:
return cast<MCEncodedFragment>(F).getContents().size();
- case MCFragment::FT_Compressed:
- return cast<MCCompressedFragment>(F).getCompressedContents().size();
case MCFragment::FT_Fill:
return cast<MCFillFragment>(F).getSize();
break;
}
- case MCFragment::FT_Compressed:
- ++stats::EmittedDataFragments;
- OW->WriteBytes(cast<MCCompressedFragment>(F).getCompressedContents());
- break;
-
case MCFragment::FT_Data:
++stats::EmittedDataFragments;
writeFragmentContents(F, OW);
case MCFragment::FT_LEB: {
const MCLEBFragment &LF = cast<MCLEBFragment>(F);
- OW->WriteBytes(LF.getContents().str());
+ OW->WriteBytes(LF.getContents());
break;
}
case MCFragment::FT_Dwarf: {
const MCDwarfLineAddrFragment &OF = cast<MCDwarfLineAddrFragment>(F);
- OW->WriteBytes(OF.getContents().str());
+ OW->WriteBytes(OF.getContents());
break;
}
case MCFragment::FT_DwarfFrame: {
const MCDwarfCallFrameFragment &CF = cast<MCDwarfCallFrameFragment>(F);
- OW->WriteBytes(CF.getContents().str());
+ OW->WriteBytes(CF.getContents());
break;
}
}
ie = SD->end(); it != ie; ++it) {
switch (it->getKind()) {
default: llvm_unreachable("Invalid fragment in virtual section!");
- case MCFragment::FT_Compressed:
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
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!");
+ if (DF.getContents()[i]) {
+ if (auto *ELFSec = dyn_cast<const MCSectionELF>(&SD->getSection()))
+ report_fatal_error("non-zero initializer found in section '" +
+ ELFSec->getSectionName() + "'");
+ else
+ report_fatal_error("non-zero initializer found in virtual section");
+ }
break;
}
case MCFragment::FT_Align:
Layout.getSectionAddressSize(SD));
}
-
-uint64_t MCAssembler::handleFixup(const MCAsmLayout &Layout,
- MCFragment &F,
- const MCFixup &Fixup) {
+std::pair<uint64_t, bool> MCAssembler::handleFixup(const MCAsmLayout &Layout,
+ MCFragment &F,
+ const MCFixup &Fixup) {
// Evaluate the fixup.
MCValue Target;
uint64_t FixedValue;
+ bool IsPCRel = Backend.getFixupKindInfo(Fixup.getKind()).Flags &
+ MCFixupKindInfo::FKF_IsPCRel;
if (!evaluateFixup(Layout, Fixup, &F, Target, FixedValue)) {
// The fixup was unresolved, we need a relocation. Inform the object
// writer of the relocation, and give it an opportunity to adjust the
// fixup value if need be.
- getWriter().RecordRelocation(*this, Layout, &F, Fixup, Target, FixedValue);
+ getWriter().RecordRelocation(*this, Layout, &F, Fixup, Target, IsPCRel,
+ FixedValue);
}
- return FixedValue;
+ return std::make_pair(FixedValue, IsPCRel);
}
void MCAssembler::Finish() {
for (MCEncodedFragmentWithFixups::fixup_iterator it3 = F->fixup_begin(),
ie3 = F->fixup_end(); it3 != ie3; ++it3) {
MCFixup &Fixup = *it3;
- uint64_t FixedValue = handleFixup(Layout, *F, Fixup);
+ uint64_t FixedValue;
+ bool IsPCRel;
+ std::tie(FixedValue, IsPCRel) = handleFixup(Layout, *F, Fixup);
getBackend().applyFixup(Fixup, F->getContents().data(),
- F->getContents().size(), FixedValue);
+ F->getContents().size(), FixedValue, IsPCRel);
}
}
}
}
bool MCAssembler::relaxLEB(MCAsmLayout &Layout, MCLEBFragment &LF) {
- int64_t Value = 0;
uint64_t OldSize = LF.getContents().size();
- bool IsAbs = LF.getValue().EvaluateAsAbsolute(Value, Layout);
- (void)IsAbs;
- assert(IsAbs);
+ int64_t Value;
+ bool Abs = LF.getValue().evaluateKnownAbsolute(Value, Layout);
+ if (!Abs)
+ report_fatal_error("sleb128 and uleb128 expressions must be absolute");
SmallString<8> &Data = LF.getContents();
Data.clear();
raw_svector_ostream OSE(Data);
bool MCAssembler::relaxDwarfLineAddr(MCAsmLayout &Layout,
MCDwarfLineAddrFragment &DF) {
MCContext &Context = Layout.getAssembler().getContext();
- int64_t AddrDelta = 0;
uint64_t OldSize = DF.getContents().size();
- bool IsAbs = DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, Layout);
- (void)IsAbs;
- assert(IsAbs);
+ int64_t AddrDelta;
+ bool Abs = DF.getAddrDelta().evaluateKnownAbsolute(AddrDelta, Layout);
+ assert(Abs && "We created a line delta with an invalid expression");
+ (void) Abs;
int64_t LineDelta;
LineDelta = DF.getLineDelta();
SmallString<8> &Data = DF.getContents();
bool MCAssembler::relaxDwarfCallFrameFragment(MCAsmLayout &Layout,
MCDwarfCallFrameFragment &DF) {
MCContext &Context = Layout.getAssembler().getContext();
- int64_t AddrDelta = 0;
uint64_t OldSize = DF.getContents().size();
- bool IsAbs = DF.getAddrDelta().EvaluateAsAbsolute(AddrDelta, Layout);
- (void)IsAbs;
- assert(IsAbs);
+ int64_t AddrDelta;
+ bool Abs = DF.getAddrDelta().evaluateKnownAbsolute(AddrDelta, Layout);
+ assert(Abs && "We created call frame with an invalid expression");
+ (void) Abs;
SmallString<8> &Data = DF.getContents();
Data.clear();
raw_svector_ostream OSE(Data);
// remain NULL if none were relaxed.
// When a fragment is relaxed, all the fragments following it should get
// invalidated because their offset is going to change.
- MCFragment *FirstRelaxedFragment = NULL;
+ MCFragment *FirstRelaxedFragment = nullptr;
// Attempt to relax all the fragments in the section.
for (MCSectionData::iterator I = SD.begin(), IE = SD.end(); I != IE; ++I) {
switch (getKind()) {
case MCFragment::FT_Align: OS << "MCAlignFragment"; break;
case MCFragment::FT_Data: OS << "MCDataFragment"; break;
- case MCFragment::FT_Compressed:
- OS << "MCCompressedFragment"; break;
case MCFragment::FT_CompactEncodedInst:
OS << "MCCompactEncodedInstFragment"; break;
case MCFragment::FT_Fill: OS << "MCFillFragment"; break;
<< " MaxBytesToEmit:" << AF->getMaxBytesToEmit() << ">";
break;
}
- case MCFragment::FT_Compressed:
case MCFragment::FT_Data: {
const MCDataFragment *DF = cast<MCDataFragment>(this);
OS << "\n ";
OS << "]>";
}
-void MCSymbolData::dump() {
+void MCSymbolData::dump() const {
raw_ostream &OS = llvm::errs();
OS << "<MCSymbolData Symbol:" << getSymbol()
- << " Fragment:" << getFragment() << " Offset:" << getOffset()
- << " Flags:" << getFlags() << " Index:" << getIndex();
+ << " Fragment:" << getFragment();
+ if (!isCommon())
+ OS << " Offset:" << getOffset();
+ OS << " Flags:" << getFlags() << " Index:" << getIndex();
if (isCommon())
OS << " (common, size:" << getCommonSize()
<< " align: " << getCommonAlignment() << ")";
projects / oota-llvm.git / blobdiff