llvm-6502/lib/MC/MCAsmStreamer.cpp
Daniel Dunbar 8906ff1b9d llvm-mc: Clean up some handling of symbol/section association to be more correct
(external was really undefined and there wasn't an explicit representation for
absolute symbols).
 - This still needs some cleanup to how the absolute "pseudo" section is dealt
   with, but I haven't figured out the nicest approach yet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79733 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-22 07:22:36 +00:00

320 lines
10 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/CodeGen/AsmPrinter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Target/TargetAsmInfo.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
class MCAsmStreamer : public MCStreamer {
raw_ostream &OS;
const TargetAsmInfo &TAI;
AsmPrinter *Printer;
public:
MCAsmStreamer(MCContext &Context, raw_ostream &_OS, const TargetAsmInfo &tai,
AsmPrinter *_AsmPrinter)
: MCStreamer(Context), OS(_OS), TAI(tai), Printer(_AsmPrinter) {}
~MCAsmStreamer() {}
/// @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.
/// Allow printing symbols directly to a raw_ostream with proper quoting.
static inline raw_ostream &operator<<(raw_ostream &os, const MCSymbol *S) {
S->print(os);
return os;
}
/// Allow printing values directly to a raw_ostream.
static inline raw_ostream &operator<<(raw_ostream &os, const MCValue &Value) {
Value.print(os);
return os;
}
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 MCValue truncateToSize(const MCValue &Value, unsigned Bytes) {
return MCValue::get(Value.getSymA(), Value.getSymB(),
truncateToSize(Value.getConstant(), Bytes));
}
void MCAsmStreamer::SwitchSection(const MCSection *Section) {
assert(Section && "Cannot switch to a null section!");
if (Section != CurSection) {
CurSection = Section;
Section->PrintSwitchToSection(TAI, 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 MCValue &Value,
bool MakeAbsolute) {
// Only absolute symbols can be redefined.
assert((Symbol->isUndefined() || Symbol->isAbsolute()) &&
"Cannot define a symbol twice!");
if (MakeAbsolute) {
OS << ".set " << Symbol << ", " << Value << '\n';
// HACK: If the value isn't already absolute, set the symbol value to
// itself, we want to use the .set absolute value, not the actual
// expression.
if (!Value.isAbsolute())
getContext().SetSymbolValue(Symbol, MCValue::get(Symbol));
else
getContext().SetSymbolValue(Symbol, Value);
} else {
OS << Symbol << " = " << Value << '\n';
getContext().SetSymbolValue(Symbol, Value);
}
}
void MCAsmStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
SymbolAttr Attribute) {
switch (Attribute) {
case Global: OS << ".globl"; break;
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::EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value) {
OS << ".lsym" << ' ' << Symbol << ',' << Value << '\n';
}
void MCAsmStreamer::EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
unsigned Pow2Alignment, bool IsLocal) {
if (IsLocal)
OS << ".lcomm";
else
OS << ".comm";
OS << ' ' << Symbol << ',' << Size;
if (Pow2Alignment != 0)
OS << ',' << Pow2Alignment;
OS << '\n';
}
void MCAsmStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
unsigned Size, unsigned Pow2Alignment) {
// 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 (Pow2Alignment != 0)
OS << ',' << Pow2Alignment;
}
OS << '\n';
}
void MCAsmStreamer::EmitBytes(const StringRef &Data) {
assert(CurSection && "Cannot emit contents before setting section!");
for (unsigned i = 0, e = Data.size(); i != e; ++i)
OS << ".byte " << (unsigned) (unsigned char) Data[i] << '\n';
}
void MCAsmStreamer::EmitValue(const MCValue &Value, unsigned Size) {
assert(CurSection && "Cannot emit contents before setting section!");
// Need target hooks to know how to print this.
switch (Size) {
default:
llvm_unreachable("Invalid size for machine code value!");
case 1: OS << ".byte"; break;
case 2: OS << ".short"; break;
case 4: OS << ".long"; break;
case 8: OS << ".quad"; break;
}
OS << ' ' << truncateToSize(Value, Size) << '\n';
}
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 << TAI.getAlignDirective(); break;
// FIXME: use TAI for this!
case 2: OS << ".p2alignw "; break;
case 4: OS << ".p2alignl "; break;
case 8: llvm_unreachable("Unsupported alignment size!");
}
if (TAI.getAlignmentIsInBytes())
OS << ByteAlignment;
else
OS << Log2_32(ByteAlignment);
if (Value || MaxBytesToEmit) {
OS << ", " << 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 TAI.
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 MCValue &Offset,
unsigned char Value) {
// FIXME: Verify that Offset is associated with the current section.
OS << ".org " << Offset << ", " << (unsigned) Value << '\n';
}
static raw_ostream &operator<<(raw_ostream &OS, const MCOperand &Op) {
if (Op.isReg())
return OS << "reg:" << Op.getReg();
if (Op.isImm())
return OS << "imm:" << Op.getImm();
if (Op.isMBBLabel())
return OS << "mbblabel:("
<< Op.getMBBLabelFunction() << ", " << Op.getMBBLabelBlock();
assert(Op.isMCValue() && "Invalid operand!");
return OS << "val:" << Op.getMCValue();
}
void MCAsmStreamer::EmitInstruction(const MCInst &Inst) {
assert(CurSection && "Cannot emit contents before setting section!");
// If we have an AsmPrinter, use that to print.
if (Printer) {
Printer->printMCInst(&Inst);
return;
}
// Otherwise fall back to a structural printing for now. Eventually we should
// always have access to the target specific printer.
OS << "MCInst("
<< "opcode=" << Inst.getOpcode() << ", "
<< "operands=[";
for (unsigned i = 0, e = Inst.getNumOperands(); i != e; ++i) {
if (i)
OS << ", ";
OS << Inst.getOperand(i);
}
OS << "])\n";
}
void MCAsmStreamer::Finish() {
OS.flush();
}
MCStreamer *llvm::createAsmStreamer(MCContext &Context, raw_ostream &OS,
const TargetAsmInfo &TAI, AsmPrinter *AP) {
return new MCAsmStreamer(Context, OS, TAI, AP);
}