#ifndef LLVM_MC_MCOBJECTWRITER_H
#define LLVM_MC_MCOBJECTWRITER_H
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/EndianStream.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/System/DataTypes.h"
#include <cassert>
namespace llvm {
-class MCAsmFixup;
class MCAsmLayout;
class MCAssembler;
+class MCFixup;
class MCFragment;
+class MCSymbolRefExpr;
class MCValue;
-class raw_ostream;
-/// MCObjectWriter - Defines the object file and target independent interfaces
-/// used by the assembler backend to write native file format object files.
+/// Defines the object file and target independent interfaces used by the
+/// assembler backend to write native file format object files.
///
/// The object writer contains a few callbacks used by the assembler to allow
/// the object writer to modify the assembler data structures at appropriate
/// points. Once assembly is complete, the object writer is given the
/// MCAssembler instance, which contains all the symbol and section data which
-/// should be emitted as part of WriteObject().
+/// should be emitted as part of writeObject().
///
/// The object writer also contains a number of helper methods for writing
/// binary data to the output stream.
class MCObjectWriter {
- MCObjectWriter(const MCObjectWriter &); // DO NOT IMPLEMENT
- void operator=(const MCObjectWriter &); // DO NOT IMPLEMENT
+ MCObjectWriter(const MCObjectWriter &) = delete;
+ void operator=(const MCObjectWriter &) = delete;
protected:
- raw_ostream &OS;
+ raw_pwrite_stream &OS;
unsigned IsLittleEndian : 1;
protected: // Can only create subclasses.
- MCObjectWriter(raw_ostream &_OS, bool _IsLittleEndian)
- : OS(_OS), IsLittleEndian(_IsLittleEndian) {}
+ MCObjectWriter(raw_pwrite_stream &OS, bool IsLittleEndian)
+ : OS(OS), IsLittleEndian(IsLittleEndian) {}
public:
virtual ~MCObjectWriter();
+ /// lifetime management
+ virtual void reset() {}
+
bool isLittleEndian() const { return IsLittleEndian; }
raw_ostream &getStream() { return OS; }
- /// @name High-Level API
+ /// \name High-Level API
/// @{
- /// Perform any late binding of symbols (for example, to assign symbol indices
- /// for use when generating relocations).
+ /// Perform any late binding of symbols (for example, to assign symbol
+ /// indices for use when generating relocations).
///
/// This routine is called by the assembler after layout and relaxation is
/// complete.
- virtual void ExecutePostLayoutBinding(MCAssembler &Asm) = 0;
+ virtual void executePostLayoutBinding(MCAssembler &Asm,
+ const MCAsmLayout &Layout) = 0;
/// Record a relocation entry.
///
/// This routine is called by the assembler after layout and relaxation, and
/// post layout binding. The implementation is responsible for storing
/// information about the relocation so that it can be emitted during
- /// WriteObject().
- virtual void RecordRelocation(const MCAssembler &Asm,
- const MCAsmLayout &Layout,
+ /// writeObject().
+ virtual void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
const MCFragment *Fragment,
- const MCAsmFixup &Fixup, MCValue Target,
- uint64_t &FixedValue) = 0;
+ const MCFixup &Fixup, MCValue Target,
+ bool &IsPCRel, uint64_t &FixedValue) = 0;
+
+ /// Check whether the difference (A - B) between two symbol references is
+ /// fully resolved.
+ ///
+ /// Clients are not required to answer precisely and may conservatively return
+ /// false, even when a difference is fully resolved.
+ bool isSymbolRefDifferenceFullyResolved(const MCAssembler &Asm,
+ const MCSymbolRefExpr *A,
+ const MCSymbolRefExpr *B,
+ bool InSet) const;
+
+ virtual bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
+ const MCSymbol &SymA,
+ const MCFragment &FB,
+ bool InSet,
+ bool IsPCRel) const;
+
+ /// True if this symbol (which is a variable) is weak. This is not
+ /// just STB_WEAK, but more generally whether or not we can evaluate
+ /// past it.
+ virtual bool isWeak(const MCSymbol &Sym) const;
/// Write the object file.
///
/// This routine is called by the assembler after layout and relaxation is
/// complete, fixups have been evaluated and applied, and relocations
/// generated.
- virtual void WriteObject(const MCAssembler &Asm,
- const MCAsmLayout &Layout) = 0;
+ virtual void writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) = 0;
/// @}
- /// @name Binary Output
+ /// \name Binary Output
/// @{
- void Write8(uint8_t Value) {
- OS << char(Value);
- }
+ void write8(uint8_t Value) { OS << char(Value); }
- void WriteLE16(uint16_t Value) {
- Write8(uint8_t(Value >> 0));
- Write8(uint8_t(Value >> 8));
+ void writeLE16(uint16_t Value) {
+ support::endian::Writer<support::little>(OS).write(Value);
}
- void WriteLE32(uint32_t Value) {
- WriteLE16(uint16_t(Value >> 0));
- WriteLE16(uint16_t(Value >> 16));
+ void writeLE32(uint32_t Value) {
+ support::endian::Writer<support::little>(OS).write(Value);
}
- void WriteLE64(uint64_t Value) {
- WriteLE32(uint32_t(Value >> 0));
- WriteLE32(uint32_t(Value >> 32));
+ void writeLE64(uint64_t Value) {
+ support::endian::Writer<support::little>(OS).write(Value);
}
- void WriteBE16(uint16_t Value) {
- Write8(uint8_t(Value >> 8));
- Write8(uint8_t(Value >> 0));
+ void writeBE16(uint16_t Value) {
+ support::endian::Writer<support::big>(OS).write(Value);
}
- void WriteBE32(uint32_t Value) {
- WriteBE16(uint16_t(Value >> 16));
- WriteBE16(uint16_t(Value >> 0));
+ void writeBE32(uint32_t Value) {
+ support::endian::Writer<support::big>(OS).write(Value);
}
- void WriteBE64(uint64_t Value) {
- WriteBE32(uint32_t(Value >> 32));
- WriteBE32(uint32_t(Value >> 0));
+ void writeBE64(uint64_t Value) {
+ support::endian::Writer<support::big>(OS).write(Value);
}
- void Write16(uint16_t Value) {
+ void write16(uint16_t Value) {
if (IsLittleEndian)
- WriteLE16(Value);
+ writeLE16(Value);
else
- WriteBE16(Value);
+ writeBE16(Value);
}
- void Write32(uint32_t Value) {
+ void write32(uint32_t Value) {
if (IsLittleEndian)
- WriteLE32(Value);
+ writeLE32(Value);
else
- WriteBE32(Value);
+ writeBE32(Value);
}
- void Write64(uint64_t Value) {
+ void write64(uint64_t Value) {
if (IsLittleEndian)
- WriteLE64(Value);
+ writeLE64(Value);
else
- WriteBE64(Value);
+ writeBE64(Value);
}
void WriteZeros(unsigned N) {
- const char Zeros[16] = { 0 };
+ const char Zeros[16] = {0};
for (unsigned i = 0, e = N / 16; i != e; ++i)
OS << StringRef(Zeros, 16);
OS << StringRef(Zeros, N % 16);
}
- void WriteBytes(StringRef Str, unsigned ZeroFillSize = 0) {
+ void writeBytes(const SmallVectorImpl<char> &ByteVec,
+ unsigned ZeroFillSize = 0) {
+ writeBytes(StringRef(ByteVec.data(), ByteVec.size()), ZeroFillSize);
+ }
+
+ void writeBytes(StringRef Str, unsigned ZeroFillSize = 0) {
+ // TODO: this version may need to go away once all fragment contents are
+ // converted to SmallVector<char, N>
+ assert(
+ (ZeroFillSize == 0 || Str.size() <= ZeroFillSize) &&
+ "data size greater than fill size, unexpected large write will occur");
OS << Str;
if (ZeroFillSize)
WriteZeros(ZeroFillSize - Str.size());