diff options
Diffstat (limited to 'lib/CodeGen/ELFWriter.h')
-rw-r--r-- | lib/CodeGen/ELFWriter.h | 70 |
1 files changed, 54 insertions, 16 deletions
diff --git a/lib/CodeGen/ELFWriter.h b/lib/CodeGen/ELFWriter.h index 8a380f0..39577d9 100644 --- a/lib/CodeGen/ELFWriter.h +++ b/lib/CodeGen/ELFWriter.h @@ -16,7 +16,7 @@ #include "llvm/ADT/SetVector.h" #include "llvm/CodeGen/MachineFunctionPass.h" -#include "llvm/Support/OutputBuffer.h" +#include "llvm/Support/Debug.h" #include "llvm/Target/TargetAsmInfo.h" #include "llvm/Target/TargetELFWriterInfo.h" #include "ELF.h" @@ -89,7 +89,7 @@ namespace llvm { bool doFinalization(Module &M); private: - // Blob containing the Elf header + /// Blob containing the Elf header BinaryObject ElfHdr; /// SectionList - This is the list of sections that we have emitted to the @@ -102,14 +102,35 @@ namespace llvm { /// 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, + 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(ELFSection(Name, isLittleEndian, is64Bit)); + // 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; @@ -119,11 +140,25 @@ namespace llvm { 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); } + /// 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); } @@ -136,25 +171,23 @@ namespace llvm { 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); } - /// SymbolList - 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> 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; + 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 @@ -165,15 +198,20 @@ namespace llvm { unsigned ELFHdr_e_shnum_Offset; // e_shnum in ELF header. private: - void EmitGlobal(GlobalVariable *GV); + 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(); }; } |