llvm-6502/lib/MC/WinCOFFStreamer.cpp
Rafael Espindola fc5436c951 Always print the implicit .text at the start of an asm file.
Before llvm-mc would print it, but llc was assuming that it would produce
another section changing directive before one was needed. That assumption is
false with inline asm.

Fixes PR19049.

Another option would be to always create the section, but in the asm printer
avoid printing sections changes during initialization. That would work, but
* We do use the fact that llvm-mc prints it in testing. The tests can be changed
  if needed.
* A quick poll on IRC suggest that most developers prefer the implicit .text to
  be printed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203001 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-05 20:09:15 +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();
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() {
// 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;
}
}