llvm/lib/MC/WinCOFFStreamer.cpp
Rafael Espindola 506eb6df35 Use the default values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200781 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-04 18:34:04 +00:00

304 lines
11 KiB
C++

//===-- llvm/MC/WinCOFFStreamer.cpp -----------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains an implementation of a Win32 COFF object file streamer.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "WinCOFFStreamer"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCObjectStreamer.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSectionCOFF.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCValue.h"
#include "llvm/MC/MCWin64EH.h"
#include "llvm/Support/COFF.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
class WinCOFFStreamer : public MCObjectStreamer {
public:
MCSymbol const *CurSymbol;
WinCOFFStreamer(MCContext &Context,
MCAsmBackend &MAB,
MCCodeEmitter &CE,
raw_ostream &OS);
void AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment, bool External);
// MCStreamer interface
virtual void InitSections(bool Force);
virtual void EmitLabel(MCSymbol *Symbol);
virtual void EmitDebugLabel(MCSymbol *Symbol);
virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
virtual void EmitThumbFunc(MCSymbol *Func);
virtual bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
virtual void BeginCOFFSymbolDef(MCSymbol const *Symbol);
virtual void EmitCOFFSymbolStorageClass(int StorageClass);
virtual void EmitCOFFSymbolType(int Type);
virtual void EndCOFFSymbolDef();
virtual void EmitCOFFSectionIndex(MCSymbol const *Symbol);
virtual void EmitCOFFSecRel32(MCSymbol const *Symbol);
virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment);
virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment);
virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
uint64_t Size,unsigned ByteAlignment);
virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
uint64_t Size, unsigned ByteAlignment);
virtual void EmitFileDirective(StringRef Filename);
virtual void EmitIdent(StringRef IdentString);
virtual void EmitWin64EHHandlerData();
virtual void FinishImpl();
private:
virtual void EmitInstToData(const MCInst &Inst, const MCSubtargetInfo &STI) {
MCDataFragment *DF = getOrCreateDataFragment();
SmallVector<MCFixup, 4> Fixups;
SmallString<256> Code;
raw_svector_ostream VecOS(Code);
getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, Fixups, STI);
VecOS.flush();
// Add the fixups and data.
for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
Fixups[i].setOffset(Fixups[i].getOffset() + DF->getContents().size());
DF->getFixups().push_back(Fixups[i]);
}
DF->getContents().append(Code.begin(), Code.end());
}
};
} // end anonymous namespace.
WinCOFFStreamer::WinCOFFStreamer(MCContext &Context, MCAsmBackend &MAB,
MCCodeEmitter &CE, raw_ostream &OS)
: MCObjectStreamer(Context, MAB, OS, &CE), CurSymbol(NULL) {}
void WinCOFFStreamer::AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment, bool External) {
assert(!Symbol->isInSection() && "Symbol must not already have a section!");
const MCSection *Section = getContext().getObjectFileInfo()->getBSSSection();
MCSectionData &SectionData = getAssembler().getOrCreateSectionData(*Section);
if (SectionData.getAlignment() < ByteAlignment)
SectionData.setAlignment(ByteAlignment);
MCSymbolData &SymbolData = getAssembler().getOrCreateSymbolData(*Symbol);
SymbolData.setExternal(External);
AssignSection(Symbol, Section);
if (ByteAlignment != 1)
new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectionData);
SymbolData.setFragment(new MCFillFragment(0, 0, Size, &SectionData));
}
// MCStreamer interface
void WinCOFFStreamer::InitSections(bool Force) {
// FIXME: this is identical to the ELF one.
// This emulates the same behavior of GNU as. This makes it easier
// to compare the output as the major sections are in the same order.
SwitchSection(getContext().getObjectFileInfo()->getTextSection());
EmitCodeAlignment(4);
SwitchSection(getContext().getObjectFileInfo()->getDataSection());
EmitCodeAlignment(4);
SwitchSection(getContext().getObjectFileInfo()->getBSSSection());
EmitCodeAlignment(4);
SwitchSection(getContext().getObjectFileInfo()->getTextSection());
}
void WinCOFFStreamer::EmitLabel(MCSymbol *Symbol) {
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
MCObjectStreamer::EmitLabel(Symbol);
}
void WinCOFFStreamer::EmitDebugLabel(MCSymbol *Symbol) {
EmitLabel(Symbol);
}
void WinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
llvm_unreachable("not implemented");
}
void WinCOFFStreamer::EmitThumbFunc(MCSymbol *Func) {
llvm_unreachable("not implemented");
}
bool WinCOFFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
MCSymbolAttr Attribute) {
assert(Symbol && "Symbol must be non-null!");
assert((Symbol->isInSection()
? Symbol->getSection().getVariant() == MCSection::SV_COFF
: true) && "Got non-COFF section in the COFF backend!");
switch (Attribute) {
case MCSA_WeakReference:
case MCSA_Weak: {
MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
SD.modifyFlags(COFF::SF_WeakExternal, COFF::SF_WeakExternal);
SD.setExternal(true);
}
break;
case MCSA_Global:
getAssembler().getOrCreateSymbolData(*Symbol).setExternal(true);
break;
default:
return false;
}
return true;
}
void WinCOFFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
llvm_unreachable("not implemented");
}
void WinCOFFStreamer::BeginCOFFSymbolDef(MCSymbol const *Symbol) {
assert((Symbol->isInSection()
? Symbol->getSection().getVariant() == MCSection::SV_COFF
: true) && "Got non-COFF section in the COFF backend!");
assert(CurSymbol == NULL && "EndCOFFSymbolDef must be called between calls "
"to BeginCOFFSymbolDef!");
CurSymbol = Symbol;
}
void WinCOFFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
assert((StorageClass & ~0xFF) == 0 && "StorageClass must only have data in "
"the first byte!");
getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
StorageClass << COFF::SF_ClassShift,
COFF::SF_ClassMask);
}
void WinCOFFStreamer::EmitCOFFSymbolType(int Type) {
assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
assert((Type & ~0xFFFF) == 0 && "Type must only have data in the first 2 "
"bytes");
getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
Type << COFF::SF_TypeShift,
COFF::SF_TypeMask);
}
void WinCOFFStreamer::EndCOFFSymbolDef() {
assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
CurSymbol = NULL;
}
void WinCOFFStreamer::EmitCOFFSectionIndex(MCSymbol const *Symbol) {
MCDataFragment *DF = getOrCreateDataFragment();
DF->getFixups().push_back(MCFixup::Create(
DF->getContents().size(), MCSymbolRefExpr::Create(Symbol, getContext()),
FK_SecRel_2));
DF->getContents().resize(DF->getContents().size() + 4, 0);
}
void WinCOFFStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol) {
MCDataFragment *DF = getOrCreateDataFragment();
DF->getFixups().push_back(MCFixup::Create(
DF->getContents().size(), MCSymbolRefExpr::Create(Symbol, getContext()),
FK_SecRel_4));
DF->getContents().resize(DF->getContents().size() + 4, 0);
}
void WinCOFFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
llvm_unreachable("not implemented");
}
void WinCOFFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) {
assert((Symbol->isInSection()
? Symbol->getSection().getVariant() == MCSection::SV_COFF
: true) && "Got non-COFF section in the COFF backend!");
AddCommonSymbol(Symbol, Size, ByteAlignment, true);
}
void WinCOFFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) {
assert((Symbol->isInSection()
? Symbol->getSection().getVariant() == MCSection::SV_COFF
: true) && "Got non-COFF section in the COFF backend!");
AddCommonSymbol(Symbol, Size, ByteAlignment, false);
}
void WinCOFFStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
uint64_t Size,unsigned ByteAlignment) {
llvm_unreachable("not implemented");
}
void WinCOFFStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
uint64_t Size, unsigned ByteAlignment) {
llvm_unreachable("not implemented");
}
void WinCOFFStreamer::EmitFileDirective(StringRef Filename) {
// Ignore for now, linkers don't care, and proper debug
// info will be a much large effort.
}
// TODO: Implement this if you want to emit .comment section in COFF obj files.
void WinCOFFStreamer::EmitIdent(StringRef IdentString) {
llvm_unreachable("unsupported directive");
}
void WinCOFFStreamer::EmitWin64EHHandlerData() {
MCStreamer::EmitWin64EHHandlerData();
// We have to emit the unwind info now, because this directive
// actually switches to the .xdata section!
MCWin64EHUnwindEmitter::EmitUnwindInfo(*this, getCurrentW64UnwindInfo());
}
void WinCOFFStreamer::FinishImpl() {
EmitFrames(NULL, true);
EmitW64Tables();
MCObjectStreamer::FinishImpl();
}
namespace llvm
{
MCStreamer *createWinCOFFStreamer(MCContext &Context,
MCAsmBackend &MAB,
MCCodeEmitter &CE,
raw_ostream &OS,
bool RelaxAll) {
WinCOFFStreamer *S = new WinCOFFStreamer(Context, MAB, CE, OS);
S->getAssembler().setRelaxAll(RelaxAll);
return S;
}
}