llvm/lib/MC/MCAsmStreamer.cpp
2010-01-20 17:50:30 +00:00

358 lines
12 KiB
C++

//===- lib/MC/MCAsmStreamer.cpp - Text Assembly 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/SmallString.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstPrinter.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
class MCAsmStreamer : public MCStreamer {
raw_ostream &OS;
const MCAsmInfo &MAI;
bool IsLittleEndian;
MCInstPrinter *InstPrinter;
MCCodeEmitter *Emitter;
public:
MCAsmStreamer(MCContext &Context, raw_ostream &_OS, const MCAsmInfo &tai,
bool isLittleEndian, MCInstPrinter *_Printer,
MCCodeEmitter *_Emitter)
: MCStreamer(Context), OS(_OS), MAI(tai), InstPrinter(_Printer),
Emitter(_Emitter) {}
~MCAsmStreamer() {}
bool isLittleEndian() const { return IsLittleEndian; }
/// @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 MCExpr *Value);
virtual void EmitSymbolAttribute(MCSymbol *Symbol, SymbolAttr Attribute);
virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
virtual void EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
unsigned ByteAlignment);
virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol = 0,
unsigned Size = 0, unsigned ByteAlignment = 0);
virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
virtual void EmitValue(const MCExpr *Value, unsigned Size,unsigned AddrSpace);
virtual void EmitIntValue(uint64_t Value, unsigned Size, unsigned AddrSpace);
virtual void EmitFill(uint64_t NumBytes, uint8_t FillValue,
unsigned AddrSpace);
virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
unsigned ValueSize = 1,
unsigned MaxBytesToEmit = 0);
virtual void EmitValueToOffset(const MCExpr *Offset,
unsigned char Value = 0);
virtual void EmitInstruction(const MCInst &Inst);
virtual void Finish();
/// @}
};
} // end anonymous namespace.
static inline int64_t truncateToSize(int64_t Value, unsigned Bytes) {
assert(Bytes && "Invalid size!");
return Value & ((uint64_t) (int64_t) -1 >> (64 - Bytes * 8));
}
static inline const MCExpr *truncateToSize(const MCExpr *Value,
unsigned Bytes) {
// FIXME: Do we really need this routine?
return Value;
}
void MCAsmStreamer::SwitchSection(const MCSection *Section) {
assert(Section && "Cannot switch to a null section!");
if (Section != CurSection) {
CurSection = Section;
Section->PrintSwitchToSection(MAI, OS);
}
}
void MCAsmStreamer::EmitLabel(MCSymbol *Symbol) {
assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
assert(CurSection && "Cannot emit before setting section!");
OS << *Symbol << ":\n";
Symbol->setSection(*CurSection);
}
void MCAsmStreamer::EmitAssemblerFlag(AssemblerFlag Flag) {
switch (Flag) {
default: assert(0 && "Invalid flag!");
case SubsectionsViaSymbols: OS << ".subsections_via_symbols"; break;
}
OS << '\n';
}
void MCAsmStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
// Only absolute symbols can be redefined.
assert((Symbol->isUndefined() || Symbol->isAbsolute()) &&
"Cannot define a symbol twice!");
OS << *Symbol << " = " << *Value << '\n';
// FIXME: Lift context changes into super class.
// FIXME: Set associated section.
Symbol->setValue(Value);
}
void MCAsmStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
SymbolAttr Attribute) {
switch (Attribute) {
case Global: OS << MAI.getGlobalDirective(); break; // .globl
case Hidden: OS << ".hidden "; break;
case IndirectSymbol: OS << ".indirect_symbol "; break;
case Internal: OS << ".internal "; break;
case LazyReference: OS << ".lazy_reference "; break;
case NoDeadStrip: OS << ".no_dead_strip "; break;
case PrivateExtern: OS << ".private_extern "; break;
case Protected: OS << ".protected "; break;
case Reference: OS << ".reference "; break;
case Weak: OS << ".weak "; break;
case WeakDefinition: OS << ".weak_definition "; break;
case WeakReference: OS << ".weak_reference "; break;
}
OS << *Symbol << '\n';
}
void MCAsmStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
OS << ".desc" << ' ' << *Symbol << ',' << DescValue << '\n';
}
void MCAsmStreamer::EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
unsigned ByteAlignment) {
OS << MAI.getCOMMDirective() << *Symbol << ',' << Size;
if (ByteAlignment != 0 && MAI.getCOMMDirectiveTakesAlignment()) {
if (MAI.getAlignmentIsInBytes())
OS << ',' << ByteAlignment;
else
OS << ',' << Log2_32(ByteAlignment);
}
OS << '\n';
}
void MCAsmStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
unsigned Size, unsigned ByteAlignment) {
// Note: a .zerofill directive does not switch sections.
OS << ".zerofill ";
// This is a mach-o specific directive.
const MCSectionMachO *MOSection = ((const MCSectionMachO*)Section);
OS << MOSection->getSegmentName() << "," << MOSection->getSectionName();
if (Symbol != NULL) {
OS << ',' << *Symbol << ',' << Size;
if (ByteAlignment != 0)
OS << ',' << Log2_32(ByteAlignment);
}
OS << '\n';
}
void MCAsmStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
assert(CurSection && "Cannot emit contents before setting section!");
const char *Directive = MAI.getData8bitsDirective(AddrSpace);
for (unsigned i = 0, e = Data.size(); i != e; ++i)
OS << Directive << (unsigned)(unsigned char)Data[i] << '\n';
}
/// EmitIntValue - Special case of EmitValue that avoids the client having
/// to pass in a MCExpr for constant integers.
void MCAsmStreamer::EmitIntValue(uint64_t Value, unsigned Size,
unsigned AddrSpace) {
assert(CurSection && "Cannot emit contents before setting section!");
const char *Directive = 0;
switch (Size) {
default: break;
case 1: Directive = MAI.getData8bitsDirective(AddrSpace); break;
case 2: Directive = MAI.getData16bitsDirective(AddrSpace); break;
case 4: Directive = MAI.getData32bitsDirective(AddrSpace); break;
case 8:
Directive = MAI.getData64bitsDirective(AddrSpace);
// If the target doesn't support 64-bit data, emit as two 32-bit halves.
if (Directive) break;
if (isLittleEndian()) {
EmitIntValue((uint32_t)(Value >> 0 ), 4, AddrSpace);
EmitIntValue((uint32_t)(Value >> 32), 4, AddrSpace);
} else {
EmitIntValue((uint32_t)(Value >> 32), 4, AddrSpace);
EmitIntValue((uint32_t)(Value >> 0 ), 4, AddrSpace);
}
return;
}
assert(Directive && "Invalid size for machine code value!");
OS << Directive << truncateToSize(Value, Size) << '\n';
}
void MCAsmStreamer::EmitValue(const MCExpr *Value, unsigned Size,
unsigned AddrSpace) {
assert(CurSection && "Cannot emit contents before setting section!");
const char *Directive = 0;
switch (Size) {
default: break;
case 1: Directive = MAI.getData8bitsDirective(AddrSpace); break;
case 2: Directive = MAI.getData16bitsDirective(AddrSpace); break;
case 4: Directive = MAI.getData32bitsDirective(AddrSpace); break;
case 8: Directive = MAI.getData64bitsDirective(AddrSpace); break;
}
assert(Directive && "Invalid size for machine code value!");
OS << Directive << *truncateToSize(Value, Size) << '\n';
}
/// EmitFill - Emit NumBytes bytes worth of the value specified by
/// FillValue. This implements directives such as '.space'.
void MCAsmStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
unsigned AddrSpace) {
if (NumBytes == 0) return;
if (AddrSpace == 0)
if (const char *ZeroDirective = MAI.getZeroDirective()) {
OS << ZeroDirective << NumBytes;
if (FillValue != 0)
OS << ',' << (int)FillValue;
OS << '\n';
return;
}
// Emit a byte at a time.
MCStreamer::EmitFill(NumBytes, FillValue, AddrSpace);
}
void MCAsmStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
unsigned ValueSize,
unsigned MaxBytesToEmit) {
// Some assemblers don't support non-power of two alignments, so we always
// emit alignments as a power of two if possible.
if (isPowerOf2_32(ByteAlignment)) {
switch (ValueSize) {
default: llvm_unreachable("Invalid size for machine code value!");
case 1: OS << MAI.getAlignDirective(); break;
// FIXME: use MAI for this!
case 2: OS << ".p2alignw "; break;
case 4: OS << ".p2alignl "; break;
case 8: llvm_unreachable("Unsupported alignment size!");
}
if (MAI.getAlignmentIsInBytes())
OS << ByteAlignment;
else
OS << Log2_32(ByteAlignment);
if (Value || MaxBytesToEmit) {
OS << ", 0x";
OS.write_hex(truncateToSize(Value, ValueSize));
if (MaxBytesToEmit)
OS << ", " << MaxBytesToEmit;
}
OS << '\n';
return;
}
// Non-power of two alignment. This is not widely supported by assemblers.
// FIXME: Parameterize this based on MAI.
switch (ValueSize) {
default: llvm_unreachable("Invalid size for machine code value!");
case 1: OS << ".balign"; break;
case 2: OS << ".balignw"; break;
case 4: OS << ".balignl"; break;
case 8: llvm_unreachable("Unsupported alignment size!");
}
OS << ' ' << ByteAlignment;
OS << ", " << truncateToSize(Value, ValueSize);
if (MaxBytesToEmit)
OS << ", " << MaxBytesToEmit;
OS << '\n';
}
void MCAsmStreamer::EmitValueToOffset(const MCExpr *Offset,
unsigned char Value) {
// FIXME: Verify that Offset is associated with the current section.
OS << ".org " << *Offset << ", " << (unsigned) Value << '\n';
}
void MCAsmStreamer::EmitInstruction(const MCInst &Inst) {
assert(CurSection && "Cannot emit contents before setting section!");
// If we have an AsmPrinter, use that to print.
if (InstPrinter) {
InstPrinter->printInst(&Inst);
OS << '\n';
// Show the encoding if we have a code emitter.
if (Emitter) {
SmallString<256> Code;
raw_svector_ostream VecOS(Code);
Emitter->EncodeInstruction(Inst, VecOS);
VecOS.flush();
OS.indent(20);
OS << " # encoding: [";
for (unsigned i = 0, e = Code.size(); i != e; ++i) {
if (i)
OS << ',';
OS << format("%#04x", uint8_t(Code[i]));
}
OS << "]\n";
}
return;
}
// Otherwise fall back to a structural printing for now. Eventually we should
// always have access to the target specific printer.
Inst.print(OS, &MAI);
OS << '\n';
}
void MCAsmStreamer::Finish() {
OS.flush();
}
MCStreamer *llvm::createAsmStreamer(MCContext &Context, raw_ostream &OS,
const MCAsmInfo &MAI, bool isLittleEndian,
MCInstPrinter *IP,
MCCodeEmitter *CE) {
return new MCAsmStreamer(Context, OS, MAI, isLittleEndian, IP, CE);
}