mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-25 20:23:11 +01:00
324 lines
12 KiB
C++
324 lines
12 KiB
C++
//===-- ELFWriter.h - Target-independent ELF writer support -----*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file was developed by Chris Lattner and is distributed under the
|
|
// University of Illinois Open Source License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines the ELFWriter class.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_CODEGEN_ELFWRITER_H
|
|
#define LLVM_CODEGEN_ELFWRITER_H
|
|
|
|
#include "llvm/CodeGen/MachineFunctionPass.h"
|
|
#include <list>
|
|
|
|
namespace llvm {
|
|
class GlobalVariable;
|
|
class Mangler;
|
|
class MachineCodeEmitter;
|
|
class ELFCodeEmitter;
|
|
|
|
/// ELFWriter - This class implements the common target-independent code for
|
|
/// writing ELF files. Targets should derive a class from this to
|
|
/// parameterize the output format.
|
|
///
|
|
class ELFWriter : public MachineFunctionPass {
|
|
friend class ELFCodeEmitter;
|
|
public:
|
|
MachineCodeEmitter &getMachineCodeEmitter() const {
|
|
return *(MachineCodeEmitter*)MCE;
|
|
}
|
|
|
|
~ELFWriter();
|
|
|
|
typedef std::vector<unsigned char> DataBuffer;
|
|
|
|
protected:
|
|
ELFWriter(std::ostream &O, TargetMachine &TM);
|
|
|
|
/// Output stream to send the resultant object file to.
|
|
///
|
|
std::ostream &O;
|
|
|
|
/// Target machine description.
|
|
///
|
|
TargetMachine &TM;
|
|
|
|
/// Mang - The object used to perform name mangling for this module.
|
|
///
|
|
Mangler *Mang;
|
|
|
|
/// MCE - The MachineCodeEmitter object that we are exposing to emit machine
|
|
/// code for functions to the .o file.
|
|
ELFCodeEmitter *MCE;
|
|
|
|
//===------------------------------------------------------------------===//
|
|
// Properties to be set by the derived class ctor, used to configure the
|
|
// ELFWriter.
|
|
|
|
// e_machine - This field is the target specific value to emit as the
|
|
// e_machine member of the ELF header.
|
|
unsigned short e_machine;
|
|
|
|
// e_flags - The machine flags for the target. This defaults to zero.
|
|
unsigned e_flags;
|
|
|
|
//===------------------------------------------------------------------===//
|
|
// Properties inferred automatically from the target machine.
|
|
//
|
|
|
|
/// is64Bit/isLittleEndian - This information is inferred from the target
|
|
/// machine directly, indicating whether to emit a 32- or 64-bit ELF file.
|
|
bool is64Bit, isLittleEndian;
|
|
|
|
/// doInitialization - Emit the file header and all of the global variables
|
|
/// for the module to the ELF file.
|
|
bool doInitialization(Module &M);
|
|
|
|
bool runOnMachineFunction(MachineFunction &MF);
|
|
|
|
|
|
/// doFinalization - Now that the module has been completely processed, emit
|
|
/// the ELF file to 'O'.
|
|
bool doFinalization(Module &M);
|
|
|
|
private:
|
|
// The buffer we accumulate the file header into. Note that this should be
|
|
// changed into something much more efficient later (and the bytecode writer
|
|
// as well!).
|
|
DataBuffer FileHeader;
|
|
|
|
/// ELFSection - This struct contains information about each section that is
|
|
/// emitted to the file. This is eventually turned into the section header
|
|
/// table at the end of the file.
|
|
struct ELFSection {
|
|
std::string Name; // Name of the section.
|
|
unsigned NameIdx; // Index in .shstrtab of name, once emitted.
|
|
unsigned Type;
|
|
unsigned Flags;
|
|
uint64_t Addr;
|
|
unsigned Offset;
|
|
unsigned Size;
|
|
unsigned Link;
|
|
unsigned Info;
|
|
unsigned Align;
|
|
unsigned EntSize;
|
|
|
|
/// SectionIdx - The number of the section in the Section Table.
|
|
///
|
|
unsigned short SectionIdx;
|
|
|
|
/// SectionData - The actual data for this section which we are building
|
|
/// up for emission to the file.
|
|
DataBuffer SectionData;
|
|
|
|
enum { SHT_NULL = 0, SHT_PROGBITS = 1, SHT_SYMTAB = 2, SHT_STRTAB = 3,
|
|
SHT_RELA = 4, SHT_HASH = 5, SHT_DYNAMIC = 6, SHT_NOTE = 7,
|
|
SHT_NOBITS = 8, SHT_REL = 9, SHT_SHLIB = 10, SHT_DYNSYM = 11 };
|
|
enum { SHN_UNDEF = 0, SHN_ABS = 0xFFF1, SHN_COMMON = 0xFFF2 };
|
|
enum { // SHF - ELF Section Header Flags
|
|
SHF_WRITE = 1 << 0, // Writable
|
|
SHF_ALLOC = 1 << 1, // Mapped into the process addr space
|
|
SHF_EXECINSTR = 1 << 2, // Executable
|
|
SHF_MERGE = 1 << 4, // Might be merged if equal
|
|
SHF_STRINGS = 1 << 5, // Contains null-terminated strings
|
|
SHF_INFO_LINK = 1 << 6, // 'sh_info' contains SHT index
|
|
SHF_LINK_ORDER = 1 << 7, // Preserve order after combining
|
|
SHF_OS_NONCONFORMING = 1 << 8, // nonstandard OS support required
|
|
SHF_GROUP = 1 << 9, // Section is a member of a group
|
|
SHF_TLS = 1 << 10 // Section holds thread-local data
|
|
};
|
|
|
|
ELFSection(const std::string &name)
|
|
: Name(name), Type(0), Flags(0), Addr(0), Offset(0), Size(0),
|
|
Link(0), Info(0), Align(0), EntSize(0) {
|
|
}
|
|
};
|
|
|
|
/// SectionList - This is the list of sections that we have emitted to the
|
|
/// file. Once the file has been completely built, the section header table
|
|
/// is constructed from this info.
|
|
std::list<ELFSection> SectionList;
|
|
unsigned NumSections; // Always = SectionList.size()
|
|
|
|
/// SectionLookup - This is a mapping from section name to section number in
|
|
/// the SectionList.
|
|
std::map<std::string, ELFSection*> SectionLookup;
|
|
|
|
/// getSection - Return the section with the specified name, creating a new
|
|
/// section if one does not already exist.
|
|
ELFSection &getSection(const std::string &Name,
|
|
unsigned Type, unsigned Flags = 0) {
|
|
ELFSection *&SN = SectionLookup[Name];
|
|
if (SN) return *SN;
|
|
|
|
SectionList.push_back(Name);
|
|
SN = &SectionList.back();
|
|
SN->SectionIdx = NumSections++;
|
|
SN->Type = Type;
|
|
SN->Flags = Flags;
|
|
return *SN;
|
|
}
|
|
|
|
ELFSection &getDataSection() {
|
|
return getSection(".data", ELFSection::SHT_PROGBITS,
|
|
ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC);
|
|
}
|
|
ELFSection &getBSSSection() {
|
|
return getSection(".bss", ELFSection::SHT_NOBITS,
|
|
ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC);
|
|
}
|
|
|
|
/// ELFSym - This struct contains information about each symbol that is
|
|
/// added to logical symbol table for the module. This is eventually
|
|
/// turned into a real symbol table in the file.
|
|
struct ELFSym {
|
|
const GlobalValue *GV; // The global value this corresponds to.
|
|
unsigned NameIdx; // Index in .strtab of name, once emitted.
|
|
uint64_t Value;
|
|
unsigned Size;
|
|
unsigned char Info;
|
|
unsigned char Other;
|
|
unsigned short SectionIdx;
|
|
|
|
enum { STB_LOCAL = 0, STB_GLOBAL = 1, STB_WEAK = 2 };
|
|
enum { STT_NOTYPE = 0, STT_OBJECT = 1, STT_FUNC = 2, STT_SECTION = 3,
|
|
STT_FILE = 4 };
|
|
ELFSym(const GlobalValue *gv) : GV(gv), Value(0), Size(0), Info(0),
|
|
Other(0), SectionIdx(0) {}
|
|
|
|
void SetBind(unsigned X) {
|
|
assert(X == (X & 0xF) && "Bind value out of range!");
|
|
Info = (Info & 0x0F) | (X << 4);
|
|
}
|
|
void SetType(unsigned X) {
|
|
assert(X == (X & 0xF) && "Type value out of range!");
|
|
Info = (Info & 0xF0) | X;
|
|
}
|
|
};
|
|
|
|
/// SymbolTable - This is the list of symbols we have emitted to the file.
|
|
/// This actually gets rearranged before emission to the file (to put the
|
|
/// local symbols first in the list).
|
|
std::vector<ELFSym> SymbolTable;
|
|
|
|
// As we complete the ELF file, we need to update fields in the ELF header
|
|
// (e.g. the location of the section table). These members keep track of
|
|
// the offset in ELFHeader of these various pieces to update and other
|
|
// locations in the file.
|
|
unsigned ELFHeader_e_shoff_Offset; // e_shoff in ELF header.
|
|
unsigned ELFHeader_e_shstrndx_Offset; // e_shstrndx in ELF header.
|
|
unsigned ELFHeader_e_shnum_Offset; // e_shnum in ELF header.
|
|
|
|
|
|
// align - Emit padding into the file until the current output position is
|
|
// aligned to the specified power of two boundary.
|
|
static void align(DataBuffer &Output, unsigned Boundary) {
|
|
assert(Boundary && (Boundary & (Boundary-1)) == 0 &&
|
|
"Must align to 2^k boundary");
|
|
size_t Size = Output.size();
|
|
if (Size & (Boundary-1)) {
|
|
// Add padding to get alignment to the correct place.
|
|
size_t Pad = Boundary-(Size & (Boundary-1));
|
|
Output.resize(Size+Pad);
|
|
}
|
|
}
|
|
|
|
static void outbyte(DataBuffer &Output, unsigned char X) {
|
|
Output.push_back(X);
|
|
}
|
|
void outhalf(DataBuffer &Output, unsigned short X) {
|
|
if (isLittleEndian) {
|
|
Output.push_back(X&255);
|
|
Output.push_back(X >> 8);
|
|
} else {
|
|
Output.push_back(X >> 8);
|
|
Output.push_back(X&255);
|
|
}
|
|
}
|
|
void outword(DataBuffer &Output, unsigned X) {
|
|
if (isLittleEndian) {
|
|
Output.push_back((X >> 0) & 255);
|
|
Output.push_back((X >> 8) & 255);
|
|
Output.push_back((X >> 16) & 255);
|
|
Output.push_back((X >> 24) & 255);
|
|
} else {
|
|
Output.push_back((X >> 24) & 255);
|
|
Output.push_back((X >> 16) & 255);
|
|
Output.push_back((X >> 8) & 255);
|
|
Output.push_back((X >> 0) & 255);
|
|
}
|
|
}
|
|
void outxword(DataBuffer &Output, uint64_t X) {
|
|
if (isLittleEndian) {
|
|
Output.push_back(unsigned(X >> 0) & 255);
|
|
Output.push_back(unsigned(X >> 8) & 255);
|
|
Output.push_back(unsigned(X >> 16) & 255);
|
|
Output.push_back(unsigned(X >> 24) & 255);
|
|
Output.push_back(unsigned(X >> 32) & 255);
|
|
Output.push_back(unsigned(X >> 40) & 255);
|
|
Output.push_back(unsigned(X >> 48) & 255);
|
|
Output.push_back(unsigned(X >> 56) & 255);
|
|
} else {
|
|
Output.push_back(unsigned(X >> 56) & 255);
|
|
Output.push_back(unsigned(X >> 48) & 255);
|
|
Output.push_back(unsigned(X >> 40) & 255);
|
|
Output.push_back(unsigned(X >> 32) & 255);
|
|
Output.push_back(unsigned(X >> 24) & 255);
|
|
Output.push_back(unsigned(X >> 16) & 255);
|
|
Output.push_back(unsigned(X >> 8) & 255);
|
|
Output.push_back(unsigned(X >> 0) & 255);
|
|
}
|
|
}
|
|
void outaddr32(DataBuffer &Output, unsigned X) {
|
|
outword(Output, X);
|
|
}
|
|
void outaddr64(DataBuffer &Output, uint64_t X) {
|
|
outxword(Output, X);
|
|
}
|
|
void outaddr(DataBuffer &Output, uint64_t X) {
|
|
if (!is64Bit)
|
|
outword(Output, (unsigned)X);
|
|
else
|
|
outxword(Output, X);
|
|
}
|
|
|
|
// fix functions - Replace an existing entry at an offset.
|
|
void fixhalf(DataBuffer &Output, unsigned short X, unsigned Offset) {
|
|
unsigned char *P = &Output[Offset];
|
|
P[0] = (X >> (isLittleEndian ? 0 : 8)) & 255;
|
|
P[1] = (X >> (isLittleEndian ? 8 : 0)) & 255;
|
|
}
|
|
|
|
void fixword(DataBuffer &Output, unsigned X, unsigned Offset) {
|
|
unsigned char *P = &Output[Offset];
|
|
P[0] = (X >> (isLittleEndian ? 0 : 24)) & 255;
|
|
P[1] = (X >> (isLittleEndian ? 8 : 16)) & 255;
|
|
P[2] = (X >> (isLittleEndian ? 16 : 8)) & 255;
|
|
P[3] = (X >> (isLittleEndian ? 24 : 0)) & 255;
|
|
}
|
|
|
|
void fixaddr(DataBuffer &Output, uint64_t X, unsigned Offset) {
|
|
if (!is64Bit)
|
|
fixword(Output, (unsigned)X, Offset);
|
|
else
|
|
assert(0 && "Emission of 64-bit data not implemented yet!");
|
|
}
|
|
|
|
private:
|
|
void EmitGlobal(GlobalVariable *GV);
|
|
|
|
void EmitSymbolTable();
|
|
|
|
void EmitSectionTableStringTable();
|
|
void OutputSectionsAndSectionTable();
|
|
};
|
|
}
|
|
|
|
#endif
|