//
// 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 is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#ifndef ELFWRITER_H
#define ELFWRITER_H
+#include "llvm/ADT/SetVector.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Target/TargetAsmInfo.h"
+#include "llvm/Target/TargetELFWriterInfo.h"
+#include "ELF.h"
#include <list>
+#include <map>
namespace llvm {
+ class BinaryObject;
+ class ConstantStruct;
+ class ELFCodeEmitter;
class GlobalVariable;
class Mangler;
class MachineCodeEmitter;
- class ELFCodeEmitter;
+ class raw_ostream;
/// ELFWriter - This class implements the common target-independent code for
/// writing ELF files. Targets should derive a class from this to
return *(MachineCodeEmitter*)MCE;
}
- ELFWriter(std::ostream &O, TargetMachine &TM);
+ ELFWriter(raw_ostream &O, TargetMachine &TM);
~ELFWriter();
typedef std::vector<unsigned char> DataBuffer;
protected:
/// Output stream to send the resultant object file to.
- ///
- std::ostream &O;
+ raw_ostream &O;
/// Target machine description.
- ///
TargetMachine &TM;
+ /// Target Elf Writer description.
+ const TargetELFWriterInfo *TEW;
+
/// 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;
+ /// TAI - Target Asm Info, provide information about section names for
+ /// globals and other target specific stuff.
+ const TargetAsmInfo *TAI;
//===------------------------------------------------------------------===//
// 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.
/// 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 bitcode 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) {
- }
- };
+ /// Blob containing the Elf header
+ BinaryObject ElfHdr;
/// 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
/// the SectionList.
std::map<std::string, ELFSection*> SectionLookup;
+ /// GblSymLookup - This is a mapping from global value to a symbol index
+ /// in the symbol table. This is useful since relocations symbol references
+ /// must be quickly mapped to a symbol table index
+ std::map<const GlobalValue*, uint32_t> GblSymLookup;
+
+ /// SymbolList - This is the list of symbols emitted to the symbol table
+ /// Local symbols go to the front and Globals to the back.
+ std::list<ELFSym> SymbolList;
+
+ /// PendingGlobals - List of externally defined symbols that we have been
+ /// asked to emit, but have not seen a reference to. When a reference
+ /// is seen, the symbol will move from this list to the SymbolList.
+ SetVector<GlobalValue*> PendingGlobals;
+
/// 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 &getSection(const std::string &Name, unsigned Type,
+ unsigned Flags = 0, unsigned Align = 0) {
ELFSection *&SN = SectionLookup[Name];
if (SN) return *SN;
- SectionList.push_back(Name);
+ // Remove tab from section name prefix. This is necessary becase TAI
+ // sometimes return a section name prefixed with a "\t" char.
+ std::string SectionName(Name);
+ size_t Pos = SectionName.find("\t");
+ if (Pos != std::string::npos)
+ SectionName.erase(Pos, 1);
+
+ SectionList.push_back(ELFSection(SectionName, isLittleEndian, is64Bit));
SN = &SectionList.back();
SN->SectionIdx = NumSections++;
SN->Type = Type;
SN->Flags = Flags;
+ SN->Link = ELFSection::SHN_UNDEF;
+ SN->Align = Align;
return *SN;
}
+ /// TODO: support mangled names here to emit the right .text section
+ /// for c++ object files.
+ ELFSection &getTextSection() {
+ return getSection(".text", ELFSection::SHT_PROGBITS,
+ ELFSection::SHF_EXECINSTR | ELFSection::SHF_ALLOC);
+ }
+
+ /// Get a constant pool section based on the section name returned by TAI
+ ELFSection &getConstantPoolSection(std::string SName, unsigned Align) {
+ return getSection(SName, ELFSection::SHT_PROGBITS,
+ ELFSection::SHF_MERGE | ELFSection::SHF_ALLOC, Align);
+ }
+
+ /// Return the relocation section of section 'S'. 'RelA' is true
+ /// if the relocation section contains entries with addends.
+ ELFSection &getRelocSection(std::string SName, bool RelA) {
+ std::string RelSName(".rel");
+ unsigned SHdrTy = RelA ? ELFSection::SHT_RELA : ELFSection::SHT_REL;
+
+ if (RelA) RelSName.append("a");
+ RelSName.append(SName);
+
+ return getSection(RelSName, SHdrTy, 0, TEW->getPrefELFAlignment());
+ }
+
+ ELFSection &getNonExecStackSection() {
+ return getSection(".note.GNU-stack", ELFSection::SHT_PROGBITS, 0, 1);
+ }
+
+ ELFSection &getSymbolTableSection() {
+ return getSection(".symtab", ELFSection::SHT_SYMTAB, 0);
+ }
+
+ ELFSection &getStringTableSection() {
+ return getSection(".strtab", ELFSection::SHT_STRTAB, 0, 1);
+ }
+
+ ELFSection &getSectionHeaderStringTableSection() {
+ return getSection(".shstrtab", ELFSection::SHT_STRTAB, 0, 1);
+ }
+
ELFSection &getDataSection() {
return getSection(".data", ELFSection::SHT_PROGBITS,
- ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC);
+ ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC, 4);
}
+
ELFSection &getBSSSection() {
return getSection(".bss", ELFSection::SHT_NOBITS,
- ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC);
+ ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC, 4);
}
- /// 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;
+ ELFSection &getNullSection() {
+ return getSection("", ELFSection::SHT_NULL, 0);
+ }
// 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.
- private:
- void EmitGlobal(GlobalVariable *GV);
-
- void EmitSymbolTable();
+ unsigned ELFHdr_e_shoff_Offset; // e_shoff in ELF header.
+ unsigned ELFHdr_e_shstrndx_Offset; // e_shstrndx in ELF header.
+ unsigned ELFHdr_e_shnum_Offset; // e_shnum in ELF header.
+ private:
+ void EmitFunctionDeclaration(const Function *F);
+ void EmitGlobalVar(const GlobalVariable *GV);
+ void EmitGlobalConstant(const Constant *C, ELFSection &GblS);
+ void EmitGlobalConstantStruct(const ConstantStruct *CVS,
+ ELFSection &GblS);
+ unsigned getGlobalELFLinkage(const GlobalVariable *GV);
+ ELFSection &getGlobalSymELFSection(const GlobalVariable *GV, ELFSym &Sym);
+ void EmitRelocations();
+ void EmitRelocation(BinaryObject &RelSec, ELFRelocation &Rel, bool HasRelA);
+ void EmitSectionHeader(BinaryObject &SHdrTab, const ELFSection &SHdr);
void EmitSectionTableStringTable();
+ void EmitSymbol(BinaryObject &SymbolTable, ELFSym &Sym);
+ void EmitSymbolTable();
+ void EmitStringTable();
void OutputSectionsAndSectionTable();
};
}
projects / oota-llvm.git / blobdiff