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//===- subzero/src/IceELFStreamer.h - Low level ELF writing -----*- C++ -*-===//
//
// The Subzero Code Generator
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Interface for serializing bits for common ELF types (words, extended
/// words, etc.), based on the ELF class.
///
//===----------------------------------------------------------------------===//
#ifndef SUBZERO_SRC_ICEELFSTREAMER_H
#define SUBZERO_SRC_ICEELFSTREAMER_H
#include "IceDefs.h"
namespace Ice {
/// Low level writer that can that can handle ELFCLASS32/64. Little endian only
/// for now.
class ELFStreamer {
ELFStreamer(const ELFStreamer &) = delete;
ELFStreamer &operator=(const ELFStreamer &) = delete;
public:
ELFStreamer() = default;
virtual ~ELFStreamer() = default;
virtual void write8(uint8_t Value) = 0;
virtual uint64_t tell() const = 0;
virtual void seek(uint64_t Off) = 0;
virtual void writeBytes(llvm::StringRef Bytes) {
for (char c : Bytes) {
write8(c);
}
}
void writeLE16(uint16_t Value) {
write8(uint8_t(Value));
write8(uint8_t(Value >> 8));
}
void writeLE32(uint32_t Value) {
writeLE16(uint16_t(Value));
writeLE16(uint16_t(Value >> 16));
}
void writeLE64(uint64_t Value) {
writeLE32(uint32_t(Value));
writeLE32(uint32_t(Value >> 32));
}
template <bool IsELF64, typename T> void writeAddrOrOffset(T Value) {
if (IsELF64)
writeLE64(Value);
else
writeLE32(Value);
}
template <bool IsELF64, typename T> void writeELFWord(T Value) {
writeLE32(Value);
}
template <bool IsELF64, typename T> void writeELFXword(T Value) {
if (IsELF64)
writeLE64(Value);
else
writeLE32(Value);
}
void writeZeroPadding(SizeT N) {
static const char Zeros[16] = {0};
for (SizeT i = 0, e = N / 16; i != e; ++i)
writeBytes(llvm::StringRef(Zeros, 16));
writeBytes(llvm::StringRef(Zeros, N % 16));
}
};
/// Implementation of ELFStreamer writing to a file.
class ELFFileStreamer : public ELFStreamer {
ELFFileStreamer() = delete;
ELFFileStreamer(const ELFFileStreamer &) = delete;
ELFFileStreamer &operator=(const ELFFileStreamer &) = delete;
public:
explicit ELFFileStreamer(Fdstream &Out) : Out(Out) {}
void write8(uint8_t Value) override { Out << char(Value); }
void writeBytes(llvm::StringRef Bytes) override { Out << Bytes; }
uint64_t tell() const override { return Out.tell(); }
void seek(uint64_t Off) override { Out.seek(Off); }
private:
Fdstream &Out;
};
} // end of namespace Ice
#endif // SUBZERO_SRC_ICEELFSTREAMER_H