Add more methods to gather target specific elf stuff
Support for .text relocations, implementing TargetELFWriter overloaded methods for x86/x86_64.
Use a map to track global values to their symbol table indexes
Code cleanup and small fixes
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73894 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ELFWriter.h b/lib/CodeGen/ELFWriter.h
index 8a380f0..c713e33 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 @@
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 @@
/// 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 @@
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);
}
@@ -146,15 +181,9 @@
ELFSection::SHF_WRITE | ELFSection::SHF_ALLOC);
}
- /// 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
@@ -165,11 +194,15 @@
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);