llvm-6502/lib/MC/WinCOFFStreamer.cpp
Rafael Espindola d80781b98b Add a InitSections method to the streamer interface.
The ELF implementation now creates text, data and bss to match the gnu as
behavior.

The text streamer still has the old MachO specific behavior since
the testsuite checks that it will error when a directive is given
before a setting the current section for example.

A nice benefit is that -n is not required anymore when producing
ELF files.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114027 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-15 21:48:40 +00:00

354 lines
13 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/MCObjectStreamer.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCValue.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCSectionCOFF.h"
#include "llvm/Target/TargetRegistry.h"
#include "llvm/Target/TargetAsmBackend.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/COFF.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
class WinCOFFStreamer : public MCObjectStreamer {
public:
MCSymbol const *CurSymbol;
WinCOFFStreamer(MCContext &Context,
TargetAsmBackend &TAB,
MCCodeEmitter &CE,
raw_ostream &OS);
void AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment, bool External);
// MCStreamer interface
virtual void InitSections();
virtual void EmitLabel(MCSymbol *Symbol);
virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
virtual void 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 EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment);
virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size);
virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
unsigned Size,unsigned ByteAlignment);
virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
uint64_t Size, unsigned ByteAlignment);
virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
virtual void EmitValue(const MCExpr *Value, unsigned Size,
unsigned AddrSpace);
virtual void EmitGPRel32Value(const MCExpr *Value);
virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
unsigned ValueSize, unsigned MaxBytesToEmit);
virtual void EmitCodeAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit);
virtual void EmitValueToOffset(const MCExpr *Offset, unsigned char Value);
virtual void EmitFileDirective(StringRef Filename);
virtual void EmitDwarfFileDirective(unsigned FileNo,StringRef Filename);
virtual void EmitInstruction(const MCInst &Instruction);
virtual void Finish();
};
} // end anonymous namespace.
WinCOFFStreamer::WinCOFFStreamer(MCContext &Context,
TargetAsmBackend &TAB,
MCCodeEmitter &CE,
raw_ostream &OS)
: MCObjectStreamer(Context, TAB, 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!");
std::string SectionName(".bss$linkonce");
SectionName.append(Symbol->getName().begin(), Symbol->getName().end());
MCSymbolData &SymbolData = getAssembler().getOrCreateSymbolData(*Symbol);
unsigned Characteristics =
COFF::IMAGE_SCN_LNK_COMDAT |
COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
COFF::IMAGE_SCN_MEM_READ |
COFF::IMAGE_SCN_MEM_WRITE;
int Selection = COFF::IMAGE_COMDAT_SELECT_LARGEST;
const MCSection *Section = MCStreamer::getContext().getCOFFSection(
SectionName, Characteristics, Selection, SectionKind::getBSS());
MCSectionData &SectionData = getAssembler().getOrCreateSectionData(*Section);
if (SectionData.getAlignment() < ByteAlignment)
SectionData.setAlignment(ByteAlignment);
SymbolData.setExternal(External);
Symbol->setSection(*Section);
if (ByteAlignment != 1)
new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectionData);
SymbolData.setFragment(new MCFillFragment(0, 0, Size, &SectionData));
}
// MCStreamer interface
void WinCOFFStreamer::InitSections() {
}
void WinCOFFStreamer::EmitLabel(MCSymbol *Symbol) {
// TODO: This is copied almost exactly from the MachOStreamer. Consider
// merging into MCObjectStreamer?
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
assert(CurSection && "Cannot emit before setting section!");
Symbol->setSection(*CurSection);
MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
// FIXME: This is wasteful, we don't necessarily need to create a data
// fragment. Instead, we should mark the symbol as pointing into the data
// fragment if it exists, otherwise we should just queue the label and set its
// fragment pointer when we emit the next fragment.
MCDataFragment *DF = getOrCreateDataFragment();
assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
SD.setFragment(DF);
SD.setOffset(DF->getContents().size());
}
void WinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
llvm_unreachable("not implemented");
}
void WinCOFFStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
// TODO: This is exactly the same as MachOStreamer. Consider merging into
// MCObjectStreamer.
getAssembler().getOrCreateSymbolData(*Symbol);
AddValueSymbols(Value);
Symbol->setVariableValue(Value);
}
void WinCOFFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
MCSymbolAttr Attribute) {
switch (Attribute) {
case MCSA_WeakReference:
getAssembler().getOrCreateSymbolData(*Symbol).modifyFlags(
COFF::SF_WeakReference,
COFF::SF_WeakReference);
break;
case MCSA_Global:
getAssembler().getOrCreateSymbolData(*Symbol).setExternal(true);
break;
default:
llvm_unreachable("unsupported attribute");
break;
}
}
void WinCOFFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
llvm_unreachable("not implemented");
}
void WinCOFFStreamer::BeginCOFFSymbolDef(MCSymbol const *Symbol) {
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::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
llvm_unreachable("not implemented");
}
void WinCOFFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) {
AddCommonSymbol(Symbol, Size, ByteAlignment, true);
}
void WinCOFFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
AddCommonSymbol(Symbol, Size, 1, false);
}
void WinCOFFStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
unsigned 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::EmitBytes(StringRef Data, unsigned AddrSpace) {
// TODO: This is copied exactly from the MachOStreamer. Consider merging into
// MCObjectStreamer?
getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
}
void WinCOFFStreamer::EmitValue(const MCExpr *Value, unsigned Size,
unsigned AddrSpace) {
assert(AddrSpace == 0 && "Address space must be 0!");
// TODO: This is copied exactly from the MachOStreamer. Consider merging into
// MCObjectStreamer?
MCDataFragment *DF = getOrCreateDataFragment();
// Avoid fixups when possible.
int64_t AbsValue;
if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue)) {
// FIXME: Endianness assumption.
for (unsigned i = 0; i != Size; ++i)
DF->getContents().push_back(uint8_t(AbsValue >> (i * 8)));
} else {
DF->addFixup(MCFixup::Create(DF->getContents().size(),
AddValueSymbols(Value),
MCFixup::getKindForSize(Size)));
DF->getContents().resize(DF->getContents().size() + Size, 0);
}
}
void WinCOFFStreamer::EmitGPRel32Value(const MCExpr *Value) {
llvm_unreachable("not implemented");
}
void WinCOFFStreamer::EmitValueToAlignment(unsigned ByteAlignment,
int64_t Value,
unsigned ValueSize,
unsigned MaxBytesToEmit) {
// TODO: This is copied exactly from the MachOStreamer. Consider merging into
// MCObjectStreamer?
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
getCurrentSectionData());
// Update the maximum alignment on the current section if necessary.
if (ByteAlignment > getCurrentSectionData()->getAlignment())
getCurrentSectionData()->setAlignment(ByteAlignment);
}
void WinCOFFStreamer::EmitCodeAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit) {
// TODO: This is copied exactly from the MachOStreamer. Consider merging into
// MCObjectStreamer?
if (MaxBytesToEmit == 0)
MaxBytesToEmit = ByteAlignment;
MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
getCurrentSectionData());
F->setEmitNops(true);
// Update the maximum alignment on the current section if necessary.
if (ByteAlignment > getCurrentSectionData()->getAlignment())
getCurrentSectionData()->setAlignment(ByteAlignment);
}
void WinCOFFStreamer::EmitValueToOffset(const MCExpr *Offset,
unsigned char Value) {
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.
}
void WinCOFFStreamer::EmitDwarfFileDirective(unsigned FileNo,
StringRef Filename) {
llvm_unreachable("not implemented");
}
void WinCOFFStreamer::EmitInstruction(const MCInst &Instruction) {
for (unsigned i = 0, e = Instruction.getNumOperands(); i != e; ++i)
if (Instruction.getOperand(i).isExpr())
AddValueSymbols(Instruction.getOperand(i).getExpr());
getCurrentSectionData()->setHasInstructions(true);
MCInstFragment *Fragment =
new MCInstFragment(Instruction, getCurrentSectionData());
raw_svector_ostream VecOS(Fragment->getCode());
getAssembler().getEmitter().EncodeInstruction(Instruction, VecOS,
Fragment->getFixups());
}
void WinCOFFStreamer::Finish() {
MCObjectStreamer::Finish();
}
namespace llvm
{
MCStreamer *createWinCOFFStreamer(MCContext &Context,
TargetAsmBackend &TAB,
MCCodeEmitter &CE,
raw_ostream &OS,
bool RelaxAll) {
WinCOFFStreamer *S = new WinCOFFStreamer(Context, TAB, CE, OS);
S->getAssembler().setRelaxAll(RelaxAll);
return S;
}
}