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//===- 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/MC/MCContext.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
namespace {
class MCAsmStreamer : public MCStreamer {
raw_ostream &OS;
MCSection *CurSection;
public:
MCAsmStreamer(MCContext &Context, raw_ostream &_OS)
: MCStreamer(Context), OS(_OS), CurSection(0) {}
~MCAsmStreamer() {}
/// @name MCStreamer Interface
/// @{
virtual void SwitchSection(MCSection *Section);
virtual void EmitLabel(MCSymbol *Symbol);
virtual void SubsectionsViaSymbols(void);
virtual void EmitAssignment(MCSymbol *Symbol, const MCValue &Value,
bool MakeAbsolute = false);
virtual void EmitSymbolAttribute(MCSymbol *Symbol, SymbolAttr Attribute);
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 AbortAssembly(const char *AbortReason = NULL);
virtual void EmitBytes(const char *Data, unsigned Length);
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();
/// @}
};
}
/// Allow printing values directly to a raw_ostream.
static inline raw_ostream &operator<<(raw_ostream &os, const MCValue &Value) {
if (Value.getSymA()) {
os << Value.getSymA()->getName();
if (Value.getSymB())
os << " - " << Value.getSymB()->getName();
if (Value.getConstant())
os << " + " << Value.getConstant();
} else {
assert(!Value.getSymB() && "Invalid machine code value!");
os << Value.getConstant();
}
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(MCSection *Section) {
if (Section != CurSection) {
CurSection = Section;
// FIXME: Really we would like the segment, flags, etc. to be separate
// values instead of embedded in the name. Not all assemblers understand all
// this stuff though.
OS << ".section " << Section->getName() << "\n";
}
}
void MCAsmStreamer::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!");
OS << Symbol->getName() << ":\n";
Symbol->setSection(CurSection);
Symbol->setExternal(false);
}
void MCAsmStreamer::SubsectionsViaSymbols(void) {
OS << ".subsections_via_symbols\n";
}
void MCAsmStreamer::AbortAssembly(const char *AbortReason) {
OS << ".abort";
if (AbortReason != NULL)
OS << ' ' << AbortReason;
OS << '\n';
}
void MCAsmStreamer::EmitAssignment(MCSymbol *Symbol, const MCValue &Value,
bool MakeAbsolute) {
assert(!Symbol->getSection() && "Cannot assign to a label!");
if (MakeAbsolute) {
OS << ".set " << Symbol->getName() << ", " << Value << '\n';
} else {
OS << Symbol->getName() << " = " << 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->getName() << '\n';
}
void MCAsmStreamer::EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
unsigned Pow2Alignment, bool IsLocal) {
if (IsLocal)
OS << ".lcomm";
else
OS << ".comm";
OS << ' ' << Symbol->getName() << ',' << 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
// FIXME: Really we would like the segment and section names as well as the
// section type to be separate values instead of embedded in the name. Not
// all assemblers understand all this stuff though.
OS << ".zerofill " << Section->getName();
if (Symbol != NULL) {
OS << ',' << Symbol->getName() << ',' << Size;
if (Pow2Alignment != 0)
OS << ',' << Pow2Alignment;
}
OS << '\n';
}
void MCAsmStreamer::EmitBytes(const char *Data, unsigned Length) {
assert(CurSection && "Cannot emit contents before setting section!");
for (unsigned i = 0; i != Length; ++i)
OS << ".byte " << (unsigned) 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 .balign, so we always emit as .p2align if
// this is a power of two. Otherwise we assume the client knows the target
// supports .balign and use that.
unsigned Pow2 = Log2_32(ByteAlignment);
bool IsPow2 = (1U << Pow2) == ByteAlignment;
switch (ValueSize) {
default:
LLVM_UNREACHABLE("Invalid size for machine code value!");
case 8:
LLVM_UNREACHABLE("Unsupported alignment size!");
case 1: OS << (IsPow2 ? ".p2align" : ".balign"); break;
case 2: OS << (IsPow2 ? ".p2alignw" : ".balignw"); break;
case 4: OS << (IsPow2 ? ".p2alignl" : ".balignl"); break;
}
OS << ' ' << (IsPow2 ? Pow2 : 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!");
// FIXME: Implement proper printing.
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) {
return new MCAsmStreamer(Context, OS);
}
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