//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file was developed by Chris Lattner and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
#define LLVM_CODEGEN_ELFWRITER_H
#include "llvm/CodeGen/MachineFunctionPass.h"
+#include <list>
namespace llvm {
class GlobalVariable;
~ELFWriter();
+ typedef std::vector<unsigned char> DataBuffer;
+
protected:
ELFWriter(std::ostream &O, TargetMachine &TM);
bool doFinalization(Module &M);
private:
- // The buffer we are accumulating the file into. Note that this should be
+ // 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!).
- std::vector<unsigned char> OutputBuffer;
+ DataBuffer FileHeader;
/// ELFSection - This struct contains information about each section that is
- /// emitted to the OutputBuffer. This is eventually turned into the section
- /// header table at the end of the file.
+ /// 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 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 };
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
+ SHF_TLS = 1 << 10 // Section holds thread-local data
};
- ELFSection(const char *name = "", unsigned offset = 0)
- : Name(name), Type(0), Flags(0), Addr(0), Offset(offset), Size(0),
+ 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::vector<ELFSection> SectionList;
+ 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
};
/// SymbolTable - This is the list of symbols we have emitted to the file.
- /// This actually gets rearranged before emission to OutputBuffer (to put
- /// the local symbols first in the list).
+ /// This actually gets rearranged before emission to the file (to put the
+ /// local symbols first in the list).
std::vector<ELFSym> SymbolTable;
- // As we accumulate the ELF file into OutputBuffer, we occasionally need to
- // keep track of locations to update later (e.g. the location of the section
- // table in the ELF header. These members keep track of the offset in
- // OffsetBuffer of these various pieces to update and other locations in the
- // file.
+ // 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.
- void align(unsigned Boundary) {
+ static void align(DataBuffer &Output, unsigned Boundary) {
assert(Boundary && (Boundary & (Boundary-1)) == 0 &&
"Must align to 2^k boundary");
- while (OutputBuffer.size() & (Boundary-1))
- outbyte(0xAB);
+ 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);
+ }
}
- void outbyte(unsigned char X) { OutputBuffer.push_back(X); }
- void outhalf(unsigned short X) {
+ static void outbyte(DataBuffer &Output, unsigned char X) {
+ Output.push_back(X);
+ }
+ void outhalf(DataBuffer &Output, unsigned short X) {
if (isLittleEndian) {
- OutputBuffer.push_back(X&255);
- OutputBuffer.push_back(X >> 8);
+ Output.push_back(X&255);
+ Output.push_back(X >> 8);
} else {
- OutputBuffer.push_back(X >> 8);
- OutputBuffer.push_back(X&255);
+ Output.push_back(X >> 8);
+ Output.push_back(X&255);
}
}
- void outword(unsigned X) {
+ void outword(DataBuffer &Output, unsigned X) {
if (isLittleEndian) {
- OutputBuffer.push_back((X >> 0) & 255);
- OutputBuffer.push_back((X >> 8) & 255);
- OutputBuffer.push_back((X >> 16) & 255);
- OutputBuffer.push_back((X >> 24) & 255);
+ 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 {
- OutputBuffer.push_back((X >> 24) & 255);
- OutputBuffer.push_back((X >> 16) & 255);
- OutputBuffer.push_back((X >> 8) & 255);
- OutputBuffer.push_back((X >> 0) & 255);
+ 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 outaddr(uint64_t X) {
+ 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((unsigned)X);
+ outword(Output, (unsigned)X);
else
- assert(0 && "Emission of 64-bit data not implemented yet!");
+ outxword(Output, X);
}
// fix functions - Replace an existing entry at an offset.
- void fixhalf(unsigned short X, unsigned Offset) {
- unsigned char *P = &OutputBuffer[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(unsigned X, unsigned Offset) {
- unsigned char *P = &OutputBuffer[Offset];
+ 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(uint64_t X, unsigned Offset) {
+ void fixaddr(DataBuffer &Output, uint64_t X, unsigned Offset) {
if (!is64Bit)
- fixword((unsigned)X, Offset);
+ fixword(Output, (unsigned)X, Offset);
else
assert(0 && "Emission of 64-bit data not implemented yet!");
}
private:
- void EmitGlobal(GlobalVariable *GV, ELFSection &DataSection,
- ELFSection &BSSSection);
+ void EmitGlobal(GlobalVariable *GV);
void EmitSymbolTable();
void EmitSectionTableStringTable();
- void EmitSectionTable();
+ void OutputSectionsAndSectionTable();
};
}