llvm-6502/lib/MC/MCMachOStreamer.cpp
Daniel Dunbar fb4a6b3976 llvm-mc: Start MCAssembler and MCMachOStreamer.
- Together these form the (Mach-O) back end of the assembler.

 - MCAssembler is the actual assembler backend, which is designed to have a
   reasonable API. This will eventually grow to support multiple object file
   implementations, but for now its Mach-O/i386 only.

 - MCMachOStreamer adapts the MCStreamer "actions" API to the MCAssembler API,
   e.g. converting the various directives into fragments, managing state like
   the current section, and so on.

 - llvm-mc will use the new backend via '-filetype=obj', which may eventually
   be, but is not yet, since I hear that people like assemblers which actually
   assemble.

 - The only thing that works at the moment is changing sections. For the time
   being I have a Python Mach-O dumping tool in test/scripts so this stuff can
   be easily tested, eventually I expect to replace this with a real LLVM tool.

 - More doxyments to come.

I assume that since this stuff doesn't touch any of the things which are part of
2.6 that it is ok to put this in not so long before the freeze, but if someone
objects let me know, I can pull it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79612 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-21 09:11:24 +00:00

171 lines
5.2 KiB
C++

//===- lib/MC/MCMachOStreamer.cpp - Mach-O Object Output ------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCStreamer.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
namespace {
class MCMachOStreamer : public MCStreamer {
MCAssembler Assembler;
MCSectionData *CurSectionData;
DenseMap<const MCSection*, MCSectionData*> SectionMap;
public:
MCMachOStreamer(MCContext &Context, raw_ostream &_OS)
: MCStreamer(Context), Assembler(_OS), CurSectionData(0) {}
~MCMachOStreamer() {}
/// @name MCStreamer Interface
/// @{
virtual void SwitchSection(const MCSection *Section);
virtual void EmitLabel(MCSymbol *Symbol);
virtual void EmitAssemblerFlag(AssemblerFlag Flag);
virtual void EmitAssignment(MCSymbol *Symbol, const MCValue &Value,
bool MakeAbsolute = false);
virtual void EmitSymbolAttribute(MCSymbol *Symbol, SymbolAttr Attribute);
virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
virtual void EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value);
virtual void EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
unsigned Pow2Alignment, bool IsLocal);
virtual void EmitZerofill(MCSection *Section, MCSymbol *Symbol = NULL,
unsigned Size = 0, unsigned Pow2Alignment = 0);
virtual void EmitBytes(const StringRef &Data);
virtual void EmitValue(const MCValue &Value, unsigned Size);
virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
unsigned ValueSize = 1,
unsigned MaxBytesToEmit = 0);
virtual void EmitValueToOffset(const MCValue &Offset,
unsigned char Value = 0);
virtual void EmitInstruction(const MCInst &Inst);
virtual void Finish();
/// @}
};
} // end anonymous namespace.
void MCMachOStreamer::SwitchSection(const MCSection *Section) {
assert(Section && "Cannot switch to a null section!");
if (Section != CurSection) {
CurSection = Section;
MCSectionData *&Entry = SectionMap[Section];
if (!Entry)
Entry = new MCSectionData(*Section, &Assembler);
CurSectionData = Entry;
}
}
void MCMachOStreamer::EmitLabel(MCSymbol *Symbol) {
assert(Symbol->getSection() == 0 && "Cannot emit a symbol twice!");
assert(CurSection && "Cannot emit before setting section!");
assert(!getContext().GetSymbolValue(Symbol) &&
"Cannot emit symbol which was directly assigned to!");
llvm_unreachable("FIXME: Not yet implemented!");
Symbol->setSection(CurSection);
Symbol->setExternal(false);
}
void MCMachOStreamer::EmitAssemblerFlag(AssemblerFlag Flag) {
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitAssignment(MCSymbol *Symbol,
const MCValue &Value,
bool MakeAbsolute) {
assert(!Symbol->getSection() && "Cannot assign to a label!");
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
SymbolAttr Attribute) {
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value) {
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
unsigned Pow2Alignment,
bool IsLocal) {
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
unsigned Size, unsigned Pow2Alignment) {
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitBytes(const StringRef &Data) {
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitValue(const MCValue &Value, unsigned Size) {
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitValueToAlignment(unsigned ByteAlignment,
int64_t Value, unsigned ValueSize,
unsigned MaxBytesToEmit) {
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitValueToOffset(const MCValue &Offset,
unsigned char Value) {
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::EmitInstruction(const MCInst &Inst) {
llvm_unreachable("FIXME: Not yet implemented!");
}
void MCMachOStreamer::Finish() {
Assembler.Finish();
}
MCStreamer *llvm::createMachOStreamer(MCContext &Context, raw_ostream &OS) {
return new MCMachOStreamer(Context, OS);
}