void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout,
const SectionIndexMapTy &SectionIndexMap);
+ // Map from a group section to the signature symbol
+ typedef DenseMap<const MCSectionELF*, const MCSymbol*> GroupMapTy;
+ void CreateGroupSections(MCAssembler &Asm, MCAsmLayout &Layout,
+ GroupMapTy &GroupMap);
+
void ExecutePostLayoutBinding(MCAssembler &Asm);
void WriteSecHdrEntry(uint32_t Name, uint32_t Type, uint64_t Flags,
void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout);
void WriteSection(MCAssembler &Asm,
const SectionIndexMapTy &SectionIndexMap,
+ uint32_t GroupSymbolIndex,
uint64_t Offset, uint64_t Size, uint64_t Alignment,
const MCSectionELF &Section);
};
ie = Asm.end(); it != ie; ++it) {
const MCSectionELF &Section =
static_cast<const MCSectionELF &>(it->getSection());
+ if (Section.getType() != ELF::SHT_GROUP)
+ continue;
+ SectionIndexMap[&Section] = Index++;
+ }
+
+ for (MCAssembler::iterator it = Asm.begin(),
+ ie = Asm.end(); it != ie; ++it) {
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF &>(it->getSection());
+ if (Section.getType() == ELF::SHT_GROUP)
+ continue;
SectionIndexMap[&Section] = Index++;
}
}
RelaSection = Ctx.getELFSection(RelaSectionName, HasRelocationAddend ?
ELF::SHT_RELA : ELF::SHT_REL, 0,
SectionKind::getReadOnly(),
- EntrySize);
+ EntrySize, "");
MCSectionData &RelaSD = Asm.getOrCreateSectionData(*RelaSection);
RelaSD.setAlignment(Is64Bit ? 8 : 4);
const MCSectionELF *SymtabSection =
Ctx.getELFSection(".symtab", ELF::SHT_SYMTAB, 0,
SectionKind::getReadOnly(),
- EntrySize);
+ EntrySize, "");
MCSectionData &SymtabSD = Asm.getOrCreateSectionData(*SymtabSection);
SymtabSD.setAlignment(Is64Bit ? 8 : 4);
SymbolTableIndex = Asm.size();
if (NeedsSymtabShndx) {
const MCSectionELF *SymtabShndxSection =
Ctx.getELFSection(".symtab_shndx", ELF::SHT_SYMTAB_SHNDX, 0,
- SectionKind::getReadOnly(), 4);
+ SectionKind::getReadOnly(), 4, "");
SymtabShndxSD = &Asm.getOrCreateSectionData(*SymtabShndxSection);
SymtabShndxSD->setAlignment(4);
}
uint64_t Index = 1;
F->getContents() += '\x00';
+ StringMap<uint64_t> SecStringMap;
for (MCAssembler::const_iterator it = Asm.begin(),
ie = Asm.end(); it != ie; ++it) {
const MCSectionELF &Section =
static_cast<const MCSectionELF&>(it->getSection());
// FIXME: We could merge suffixes like in .text and .rela.text.
+ StringRef Name = Section.getSectionName();
+ if (SecStringMap.count(Name)) {
+ SectionStringTableIndex[&Section] = SecStringMap[Name];
+ continue;
+ }
// Remember the index into the string table so we can write it
// into the sh_name field of the section header table.
- SectionStringTableIndex[&it->getSection()] = Index;
+ SectionStringTableIndex[&Section] = Index;
+ SecStringMap[Name] = Index;
- Index += Section.getSectionName().size() + 1;
- F->getContents() += Section.getSectionName();
+ Index += Name.size() + 1;
+ F->getContents() += Name;
F->getContents() += '\x00';
}
return !SectionB && BaseSection == SectionA;
}
+void ELFObjectWriterImpl::CreateGroupSections(MCAssembler &Asm,
+ MCAsmLayout &Layout,
+ GroupMapTy &GroupMap) {
+ typedef DenseMap<const MCSymbol*, const MCSectionELF*> RevGroupMapTy;
+ // Build the groups
+ RevGroupMapTy Groups;
+ for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end();
+ it != ie; ++it) {
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF&>(it->getSection());
+ if (!(Section.getFlags() & MCSectionELF::SHF_GROUP))
+ continue;
+
+ const MCSymbol *SignatureSymbol = Section.getGroup();
+ Asm.getOrCreateSymbolData(*SignatureSymbol);
+ const MCSectionELF *&Group = Groups[SignatureSymbol];
+ if (!Group) {
+ Group = Asm.getContext().CreateELFGroupSection();
+ MCSectionData &Data = Asm.getOrCreateSectionData(*Group);
+ Data.setAlignment(4);
+ MCDataFragment *F = new MCDataFragment(&Data);
+ String32(*F, ELF::GRP_COMDAT);
+ }
+ GroupMap[Group] = SignatureSymbol;
+ }
+
+ // Add sections to the groups
+ unsigned Index = 1;
+ unsigned NumGroups = Groups.size();
+ for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end();
+ it != ie; ++it, ++Index) {
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF&>(it->getSection());
+ if (!(Section.getFlags() & MCSectionELF::SHF_GROUP))
+ continue;
+ const MCSectionELF *Group = Groups[Section.getGroup()];
+ MCSectionData &Data = Asm.getOrCreateSectionData(*Group);
+ // FIXME: we could use the previous fragment
+ MCDataFragment *F = new MCDataFragment(&Data);
+ String32(*F, NumGroups + Index);
+ }
+
+ for (RevGroupMapTy::const_iterator i = Groups.begin(), e = Groups.end();
+ i != e; ++i) {
+ const MCSectionELF *Group = i->second;
+ MCSectionData &Data = Asm.getOrCreateSectionData(*Group);
+ Asm.AddSectionToTheEnd(*Writer, Data, Layout);
+ }
+}
+
void ELFObjectWriterImpl::WriteSection(MCAssembler &Asm,
const SectionIndexMapTy &SectionIndexMap,
+ uint32_t GroupSymbolIndex,
uint64_t Offset, uint64_t Size,
uint64_t Alignment,
const MCSectionELF &Section) {
// Nothing to do.
break;
+ case ELF::SHT_GROUP: {
+ sh_link = SymbolTableIndex;
+ sh_info = GroupSymbolIndex;
+ break;
+ }
+
default:
assert(0 && "FIXME: sh_type value not supported!");
break;
void ELFObjectWriterImpl::WriteObject(MCAssembler &Asm,
const MCAsmLayout &Layout) {
+
+ GroupMapTy GroupMap;
+ CreateGroupSections(Asm, const_cast<MCAsmLayout&>(Layout), GroupMap);
+
SectionIndexMapTy SectionIndexMap;
ComputeIndexMap(Asm, SectionIndexMap);
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;
+ std::vector<const MCSectionELF*> Sections;
+ Sections.resize(NumSections);
+
+ for (SectionIndexMapTy::const_iterator i=
+ SectionIndexMap.begin(), e = SectionIndexMap.end(); i != e; ++i) {
+ const std::pair<const MCSectionELF*, uint32_t> &p = *i;
+ Sections[p.second] = p.first;
+ }
+
+ for (unsigned i = 1; i < NumSections; ++i) {
+ const MCSectionELF &Section = *Sections[i];
+ const MCSectionData &SD = Asm.getOrCreateSectionData(Section);
FileOff = RoundUpToAlignment(FileOff, SD.getAlignment());
// ... then all of the sections ...
DenseMap<const MCSection*, uint64_t> SectionOffsetMap;
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it) {
- const MCSectionData &SD = *it;
+ for (unsigned i = 1; i < NumSections; ++i) {
+ const MCSectionELF &Section = *Sections[i];
+ const MCSectionData &SD = Asm.getOrCreateSectionData(Section);
uint64_t Padding = OffsetToAlignment(FileOff, SD.getAlignment());
WriteZeros(Padding);
FileOff += Padding;
// Remember the offset into the file for this section.
- SectionOffsetMap[&it->getSection()] = FileOff;
+ SectionOffsetMap[&Section] = FileOff;
FileOff += Layout.getSectionFileSize(&SD);
- Asm.WriteSectionData(it, Layout, Writer);
+ Asm.WriteSectionData(&SD, Layout, Writer);
}
uint64_t Padding = OffsetToAlignment(FileOff, NaturalAlignment);
ShstrtabIndex >= ELF::SHN_LORESERVE ? ShstrtabIndex : 0;
WriteSecHdrEntry(0, 0, 0, 0, 0, FirstSectionSize, FirstSectionLink, 0, 0, 0);
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it) {
- const MCSectionData &SD = *it;
- const MCSectionELF &Section =
- static_cast<const MCSectionELF&>(SD.getSection());
+ for (unsigned i = 1; i < NumSections; ++i) {
+ const MCSectionELF &Section = *Sections[i];
+ const MCSectionData &SD = Asm.getOrCreateSectionData(Section);
+ uint32_t GroupSymbolIndex;
+ if (Section.getType() != ELF::SHT_GROUP)
+ GroupSymbolIndex = 0;
+ else
+ GroupSymbolIndex = getSymbolIndexInSymbolTable(Asm, GroupMap[&Section]);
- WriteSection(Asm, SectionIndexMap, SectionOffsetMap[&Section],
- Layout.getSectionSize(&SD),
+ WriteSection(Asm, SectionIndexMap, GroupSymbolIndex,
+ SectionOffsetMap[&Section], Layout.getSectionSize(&SD),
SD.getAlignment(), Section);
}
}
--- /dev/null
+// RUN: llvm-mc -filetype=obj -triple x86_64-pc-linux-gnu %s -o - | elf-dump | FileCheck %s
+
+// Test that we produce the two group sections and that they are a the beginning
+// of the file.
+
+// CHECK: # Section 0x00000001
+// CHECK-NEXT: (('sh_name', 0x00000021) # '.group'
+// CHECK-NEXT: ('sh_type', 0x00000011)
+// CHECK-NEXT: ('sh_flags', 0x00000000)
+// CHECK-NEXT: ('sh_addr', 0x00000000)
+// CHECK-NEXT: ('sh_offset', 0x00000040)
+// CHECK-NEXT: ('sh_size', 0x0000000c)
+// CHECK-NEXT: ('sh_link', 0x0000000a)
+// CHECK-NEXT: ('sh_info', 0x00000001)
+// CHECK-NEXT: ('sh_addralign', 0x00000004)
+// CHECK-NEXT: ('sh_entsize', 0x00000004)
+// CHECK-NEXT: ),
+// CHECK-NEXT: # Section 0x00000002
+// CHECK-NEXT: (('sh_name', 0x00000021) # '.group'
+// CHECK-NEXT: ('sh_type', 0x00000011)
+// CHECK-NEXT: ('sh_flags', 0x00000000)
+// CHECK-NEXT: ('sh_addr', 0x00000000)
+// CHECK-NEXT: ('sh_offset', 0x0000004c)
+// CHECK-NEXT: ('sh_size', 0x00000008)
+// CHECK-NEXT: ('sh_link', 0x0000000a)
+// CHECK-NEXT: ('sh_info', 0x00000002)
+// CHECK-NEXT: ('sh_addralign', 0x00000004)
+// CHECK-NEXT: ('sh_entsize', 0x00000004)
+
+ .section .foo,"axG",@progbits,g1,comdat
+g1:
+ nop
+
+ .section .bar,"axG",@progbits,g1,comdat
+ nop
+
+ .section .zed,"axG",@progbits,g2,comdat
+g2:
+ nop
// CHECK-NEXT: ('sh_type', 0x00000001)
// CHECK-NEXT: ('sh_flags', 0x00000006)
// CHECK-NEXT: ('sh_addr', 0x00000000)
-// CHECK-NEXT: ('sh_offset', 0x00000040)
+// CHECK-NEXT: ('sh_offset', 0x00000050)
// CHECK-NEXT: ('sh_size', 0x00000000)
// CHECK-NEXT: ('sh_link', 0x00000000)
// CHECK-NEXT: ('sh_info', 0x00000000)
// CHECK-NEXT: ('sh_addralign', 0x00000001)
// CHECK-NEXT: ('sh_entsize', 0x00000000)
// CHECK-NEXT: ),
-// CHECK-NEXT: # Section 0x00000008
+// CHECK-NEXT: # Section 0x0000000a
// CHECK-NEXT: (('sh_name', 0x0000003e) # '.fini'
// CHECK-NEXT: ('sh_type', 0x00000001)
// CHECK-NEXT: ('sh_flags', 0x00000006)
// CHECK-NEXT: ('sh_addr', 0x00000000)
-// CHECK-NEXT: ('sh_offset', 0x00000040)
+// CHECK-NEXT: ('sh_offset', 0x00000050)
// CHECK-NEXT: ('sh_size', 0x00000000)
// CHECK-NEXT: ('sh_link', 0x00000000)
// CHECK-NEXT: ('sh_info', 0x00000000)
// CHECK-NEXT: ('sh_addralign', 0x00000001)
// CHECK-NEXT: ('sh_entsize', 0x00000000)
// CHECK-NEXT: ),
-// CHECK-NEXT: # Section 0x00000009
+// CHECK-NEXT: # Section 0x0000000b
// CHECK-NEXT: (('sh_name', 0x00000044) # '.rodata'
// CHECK-NEXT: ('sh_type', 0x00000001)
// CHECK-NEXT: ('sh_flags', 0x00000002)
// CHECK-NEXT: ('sh_addr', 0x00000000)
-// CHECK-NEXT: ('sh_offset', 0x00000040)
+// CHECK-NEXT: ('sh_offset', 0x00000050)
// CHECK-NEXT: ('sh_size', 0x00000000)
// CHECK-NEXT: ('sh_link', 0x00000000)
// CHECK-NEXT: ('sh_info', 0x00000000)
// CHECK-NEXT: ),
// Test that we can parse these
+foo:
+bar:
.section .text.foo,"axG",@progbits,foo,comdat
-.section .text.bar,"axMG",@progbits,42,bar,.gnu.linkonce
+.section .text.bar,"axMG",@progbits,42,bar,comdat