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MCELF: Align symtab, relocation sections and section headers properly. Patch by Krister Wombell. 

llvm-svn: 113155
This commit is contained in:
Benjamin Kramer 2010-09-06 16:11:52 +00:00
parent 2fdb5b5955
commit 3723ba1fe0
1 changed files with 24 additions and 12 deletions
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36
llvm/lib/MC/ELFObjectWriter.cpp
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@ -103,9 +103,6 @@ namespace {
raw_ostream &OS;
// This holds the current offset into the object file.
size_t FileOff;
unsigned Is64Bit : 1;
bool HasRelocationAddend;
@ -120,7 +117,7 @@ namespace {
public:
ELFObjectWriterImpl(ELFObjectWriter *_Writer, bool _Is64Bit,
bool _HasRelAddend)
: Writer(_Writer), OS(Writer->getStream()), FileOff(0),
: Writer(_Writer), OS(Writer->getStream()),
Is64Bit(_Is64Bit), HasRelocationAddend(_HasRelAddend) {
}
@ -702,7 +699,7 @@ void ELFObjectWriterImpl::WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout,
false, EntrySize);
MCSectionData &RelaSD = Asm.getOrCreateSectionData(*RelaSection);
RelaSD.setAlignment(1);
RelaSD.setAlignment(Is64Bit ? 8 : 4);
MCDataFragment *F = new MCDataFragment(&RelaSD);
@ -832,21 +829,28 @@ void ELFObjectWriterImpl::WriteObject(const MCAssembler &Asm,
// Add 1 for the null section.
unsigned NumSections = Asm.size() + 1;
uint64_t SectionDataSize = 0;
uint64_t NaturalAlignment = Is64Bit ? 8 : 4;
uint64_t HeaderSize = Is64Bit ? sizeof(ELF::Elf64_Ehdr) : sizeof(ELF::Elf32_Ehdr);
uint64_t FileOff = HeaderSize;
for (MCAssembler::const_iterator it = Asm.begin(),
ie = Asm.end(); it != ie; ++it) {
const MCSectionData &SD = *it;
FileOff = RoundUpToAlignment(FileOff, SD.getAlignment());
// Get the size of the section in the output file (including padding).
uint64_t Size = Layout.getSectionFileSize(&SD);
SectionDataSize += Size;
FileOff += Size;
}
FileOff = RoundUpToAlignment(FileOff, NaturalAlignment);
// Write out the ELF header ...
WriteHeader(SectionDataSize, NumSections);
FileOff = Is64Bit ? sizeof(ELF::Elf64_Ehdr) : sizeof(ELF::Elf32_Ehdr);
WriteHeader(FileOff - HeaderSize, NumSections);
FileOff = HeaderSize;
// ... then all of the sections ...
DenseMap<const MCSection*, uint64_t> SectionOffsetMap;
@ -856,17 +860,25 @@ void ELFObjectWriterImpl::WriteObject(const MCAssembler &Asm,
unsigned Index = 1;
for (MCAssembler::const_iterator it = Asm.begin(),
ie = Asm.end(); it != ie; ++it) {
const MCSectionData &SD = *it;
uint64_t Padding = OffsetToAlignment(FileOff, SD.getAlignment());
WriteZeros(Padding);
FileOff += Padding;
// Remember the offset into the file for this section.
SectionOffsetMap[&it->getSection()] = FileOff;
SectionIndexMap[&it->getSection()] = Index++;
const MCSectionData &SD = *it;
FileOff += Layout.getSectionFileSize(&SD);
Asm.WriteSectionData(it, Layout, Writer);
}
uint64_t Padding = OffsetToAlignment(FileOff, NaturalAlignment);
WriteZeros(Padding);
FileOff += Padding;
// ... and then the section header table.
// Should we align the section header table?
//