#include "llvm/Support/ELF.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/StringSaver.h"
#include <vector>
using namespace llvm;
/// @name Symbol Table Data
/// @{
- StringTableBuilder StrTabBuilder;
+ BumpPtrAllocator Alloc;
+ StringSaver VersionSymSaver{Alloc};
+ StringTableBuilder StrTabBuilder{StringTableBuilder::ELF};
/// @}
unsigned StringTableIndex;
// This holds the .symtab section index.
unsigned SymbolTableIndex;
- // This holds the .symtab_shndx section index.
- unsigned SymtabShndxSectionIndex = 0;
// Sections in the order they are to be output in the section table.
std::vector<const MCSectionELF *> SectionTable;
template <typename T> void write(T Val) {
if (IsLittleEndian)
- support::endian::Writer<support::little>(OS).write(Val);
+ support::endian::Writer<support::little>(getStream()).write(Val);
else
- support::endian::Writer<support::big>(OS).write(Val);
+ support::endian::Writer<support::big>(getStream()).write(Val);
}
void writeHeader(const MCAssembler &Asm);
uint32_t GroupSymbolIndex, uint64_t Offset, uint64_t Size,
const MCSectionELF &Section);
};
-} // namespace
+}
void ELFObjectWriter::align(unsigned Alignment) {
- uint64_t Padding = OffsetToAlignment(OS.tell(), Alignment);
+ uint64_t Padding = OffsetToAlignment(getStream().tell(), Alignment);
WriteZeros(Padding);
}
uint32_t StringIndex, ELFSymbolData &MSD,
const MCAsmLayout &Layout) {
const auto &Symbol = cast<MCSymbolELF>(*MSD.Symbol);
- assert((!Symbol.getFragment() ||
- (Symbol.getFragment()->getParent() == &Symbol.getSection())) &&
- "The symbol's section doesn't match the fragment's symbol");
const MCSymbolELF *Base =
cast_or_null<MCSymbolELF>(Layout.getBaseSymbol(Symbol));
// In general, ELF has no relocations for -B. It can only represent (A + C)
// or (A + C - R). If B = R + K and the relocation is not pcrel, we can
// replace B to implement it: (A - R - K + C)
- if (IsPCRel)
- Asm.getContext().reportFatalError(
+ if (IsPCRel) {
+ Asm.getContext().reportError(
Fixup.getLoc(),
"No relocation available to represent this relative expression");
+ return;
+ }
const auto &SymB = cast<MCSymbolELF>(RefB->getSymbol());
- if (SymB.isUndefined())
- Asm.getContext().reportFatalError(
+ if (SymB.isUndefined()) {
+ Asm.getContext().reportError(
Fixup.getLoc(),
Twine("symbol '") + SymB.getName() +
"' can not be undefined in a subtraction expression");
+ return;
+ }
assert(!SymB.isAbsolute() && "Should have been folded");
const MCSection &SecB = SymB.getSection();
- if (&SecB != &FixupSection)
- Asm.getContext().reportFatalError(
+ if (&SecB != &FixupSection) {
+ Asm.getContext().reportError(
Fixup.getLoc(), "Cannot represent a difference across sections");
+ return;
+ }
- if (::isWeak(SymB))
- Asm.getContext().reportFatalError(
+ if (::isWeak(SymB)) {
+ Asm.getContext().reportError(
Fixup.getLoc(), "Cannot represent a subtraction with a weak symbol");
+ return;
+ }
uint64_t SymBOffset = Layout.getSymbolOffset(SymB);
uint64_t K = SymBOffset - FixupOffset;
SymbolTableIndex = addToSectionTable(SymtabSection);
align(SymtabSection->getAlignment());
- uint64_t SecStart = OS.tell();
+ uint64_t SecStart = getStream().tell();
// The first entry is the undefined symbol entry.
Writer.writeSymbol(0, 0, 0, 0, 0, 0, false);
Renames.count(&Symbol)))
continue;
+ if (Symbol.isTemporary() && Symbol.isUndefined()) {
+ Ctx.reportError(SMLoc(), "Undefined temporary symbol");
+ continue;
+ }
+
ELFSymbolData MSD;
MSD.Symbol = cast<MCSymbolELF>(&Symbol);
bool Local = Symbol.getBinding() == ELF::STB_LOCAL;
+ assert(Local || !Symbol.isTemporary());
+
if (Symbol.isAbsolute()) {
MSD.SectionIndex = ELF::SHN_ABS;
} else if (Symbol.isCommon()) {
// seems that this information is not easily accessible from the
// ELFObjectWriter.
StringRef Name = Symbol.getName();
+ SmallString<32> Buf;
if (!Name.startswith("?") && !Name.startswith("@?") &&
!Name.startswith("__imp_?") && !Name.startswith("__imp_@?")) {
// This symbol isn't following the MSVC C++ name mangling convention. We
// can thus safely interpret the @@@ in symbol names as specifying symbol
// versioning.
- SmallString<32> Buf;
size_t Pos = Name.find("@@@");
if (Pos != StringRef::npos) {
Buf += Name.substr(0, Pos);
unsigned Skip = MSD.SectionIndex == ELF::SHN_UNDEF ? 2 : 1;
Buf += Name.substr(Pos + Skip);
- Name = Buf;
+ Name = VersionSymSaver.save(Buf.c_str());
}
}
// Sections have their own string table
- if (Symbol.getType() != ELF::STT_SECTION)
- MSD.Name = StrTabBuilder.add(Name);
+ if (Symbol.getType() != ELF::STT_SECTION) {
+ MSD.Name = Name;
+ StrTabBuilder.add(Name);
+ }
if (Local)
LocalSymbolData.push_back(MSD);
ExternalSymbolData.push_back(MSD);
}
+ // This holds the .symtab_shndx section index.
+ unsigned SymtabShndxSectionIndex = 0;
+
if (HasLargeSectionIndex) {
MCSectionELF *SymtabShndxSection =
Ctx.getELFSection(".symtab_shndxr", ELF::SHT_SYMTAB_SHNDX, 0, 4, "");
for (const std::string &Name : FileNames)
StrTabBuilder.add(Name);
- StrTabBuilder.finalize(StringTableBuilder::ELF);
+ StrTabBuilder.finalize();
for (const std::string &Name : FileNames)
Writer.writeSymbol(StrTabBuilder.getOffset(Name),
assert(MSD.Symbol->getBinding() != ELF::STB_LOCAL);
}
- uint64_t SecEnd = OS.tell();
+ uint64_t SecEnd = getStream().tell();
SectionOffsets[SymtabSection] = std::make_pair(SecStart, SecEnd);
ArrayRef<uint32_t> ShndxIndexes = Writer.getShndxIndexes();
}
assert(SymtabShndxSectionIndex != 0);
- SecStart = OS.tell();
+ SecStart = getStream().tell();
const MCSectionELF *SymtabShndxSection =
SectionTable[SymtabShndxSectionIndex - 1];
for (uint32_t Index : ShndxIndexes)
write(Index);
- SecEnd = OS.tell();
+ SecEnd = getStream().tell();
SectionOffsets[SymtabShndxSection] = std::make_pair(SecStart, SecEnd);
}
return RelaSection;
}
-static SmallVector<char, 128>
-getUncompressedData(const MCAsmLayout &Layout,
- const MCSection::FragmentListType &Fragments) {
- SmallVector<char, 128> UncompressedData;
- for (const MCFragment &F : Fragments) {
- const SmallVectorImpl<char> *Contents;
- switch (F.getKind()) {
- case MCFragment::FT_Data:
- Contents = &cast<MCDataFragment>(F).getContents();
- break;
- case MCFragment::FT_Dwarf:
- Contents = &cast<MCDwarfLineAddrFragment>(F).getContents();
- break;
- case MCFragment::FT_DwarfFrame:
- Contents = &cast<MCDwarfCallFrameFragment>(F).getContents();
- break;
- default:
- llvm_unreachable(
- "Not expecting any other fragment types in a debug_* section");
- }
- UncompressedData.append(Contents->begin(), Contents->end());
- }
- return UncompressedData;
-}
-
// Include the debug info compression header:
// "ZLIB" followed by 8 bytes representing the uncompressed size of the section,
// useful for consumers to preallocate a buffer to decompress into.
return;
}
- // Gather the uncompressed data from all the fragments.
- const MCSection::FragmentListType &Fragments = Section.getFragmentList();
- SmallVector<char, 128> UncompressedData =
- getUncompressedData(Layout, Fragments);
+ SmallVector<char, 128> UncompressedData;
+ raw_svector_ostream VecOS(UncompressedData);
+ raw_pwrite_stream &OldStream = getStream();
+ setStream(VecOS);
+ Asm.writeSectionData(&Section, Layout);
+ setStream(OldStream);
SmallVector<char, 128> CompressedContents;
zlib::Status Success = zlib::compress(
StringRef(UncompressedData.data(), UncompressedData.size()),
CompressedContents);
if (Success != zlib::StatusOK) {
- Asm.writeSectionData(&Section, Layout);
+ getStream() << UncompressedData;
return;
}
if (!prependCompressionHeader(UncompressedData.size(), CompressedContents)) {
- Asm.writeSectionData(&Section, Layout);
+ getStream() << UncompressedData;
return;
}
Asm.getContext().renameELFSection(&Section,
(".z" + SectionName.drop_front(1)).str());
- OS << CompressedContents;
+ getStream() << CompressedContents;
}
void ELFObjectWriter::WriteSecHdrEntry(uint32_t Name, uint32_t Type,
const MCSectionELF &Sec) {
std::vector<ELFRelocationEntry> &Relocs = Relocations[&Sec];
- // Sort the relocation entries. Most targets just sort by Offset, but some
- // (e.g., MIPS) have additional constraints.
+ // We record relocations by pushing to the end of a vector. Reverse the vector
+ // to get the relocations in the order they were created.
+ // In most cases that is not important, but it can be for special sections
+ // (.eh_frame) or specific relocations (TLS optimizations on SystemZ).
+ std::reverse(Relocs.begin(), Relocs.end());
+
+ // Sort the relocation entries. MIPS needs this.
TargetObjectWriter->sortRelocs(Asm, Relocs);
for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
const MCSectionELF *ELFObjectWriter::createStringTable(MCContext &Ctx) {
const MCSectionELF *StrtabSection = SectionTable[StringTableIndex - 1];
- OS << StrTabBuilder.data();
+ getStream() << StrTabBuilder.data();
return StrtabSection;
}
align(Section.getAlignment());
// Remember the offset into the file for this section.
- uint64_t SecStart = OS.tell();
+ uint64_t SecStart = getStream().tell();
const MCSymbolELF *SignatureSymbol = Section.getGroup();
writeSectionData(Asm, Section, Layout);
- uint64_t SecEnd = OS.tell();
+ uint64_t SecEnd = getStream().tell();
SectionOffsets[&Section] = std::make_pair(SecStart, SecEnd);
MCSectionELF *RelSection = createRelocationSection(Ctx, Section);
align(Group->getAlignment());
// Remember the offset into the file for this section.
- uint64_t SecStart = OS.tell();
+ uint64_t SecStart = getStream().tell();
const MCSymbol *SignatureSymbol = Group->getGroup();
assert(SignatureSymbol);
write(SecIndex);
}
- uint64_t SecEnd = OS.tell();
+ uint64_t SecEnd = getStream().tell();
SectionOffsets[Group] = std::make_pair(SecStart, SecEnd);
}
align(RelSection->getAlignment());
// Remember the offset into the file for this section.
- uint64_t SecStart = OS.tell();
+ uint64_t SecStart = getStream().tell();
writeRelocations(Asm, *RelSection->getAssociatedSection());
- uint64_t SecEnd = OS.tell();
+ uint64_t SecEnd = getStream().tell();
SectionOffsets[RelSection] = std::make_pair(SecStart, SecEnd);
}
{
- uint64_t SecStart = OS.tell();
+ uint64_t SecStart = getStream().tell();
const MCSectionELF *Sec = createStringTable(Ctx);
- uint64_t SecEnd = OS.tell();
+ uint64_t SecEnd = getStream().tell();
SectionOffsets[Sec] = std::make_pair(SecStart, SecEnd);
}
uint64_t NaturalAlignment = is64Bit() ? 8 : 4;
align(NaturalAlignment);
- const unsigned SectionHeaderOffset = OS.tell();
+ const unsigned SectionHeaderOffset = getStream().tell();
// ... then the section header table ...
writeSectionHeader(Layout, SectionIndexMap, SectionOffsets);
uint64_t Val = SectionHeaderOffset;
if (sys::IsLittleEndianHost != IsLittleEndian)
sys::swapByteOrder(Val);
- OS.pwrite(reinterpret_cast<char *>(&Val), sizeof(Val),
- offsetof(ELF::Elf64_Ehdr, e_shoff));
+ getStream().pwrite(reinterpret_cast<char *>(&Val), sizeof(Val),
+ offsetof(ELF::Elf64_Ehdr, e_shoff));
NumSectionsOffset = offsetof(ELF::Elf64_Ehdr, e_shnum);
} else {
uint32_t Val = SectionHeaderOffset;
if (sys::IsLittleEndianHost != IsLittleEndian)
sys::swapByteOrder(Val);
- OS.pwrite(reinterpret_cast<char *>(&Val), sizeof(Val),
- offsetof(ELF::Elf32_Ehdr, e_shoff));
+ getStream().pwrite(reinterpret_cast<char *>(&Val), sizeof(Val),
+ offsetof(ELF::Elf32_Ehdr, e_shoff));
NumSectionsOffset = offsetof(ELF::Elf32_Ehdr, e_shnum);
}
- OS.pwrite(reinterpret_cast<char *>(&NumSections), sizeof(NumSections),
- NumSectionsOffset);
+ getStream().pwrite(reinterpret_cast<char *>(&NumSections),
+ sizeof(NumSections), NumSectionsOffset);
}
bool ELFObjectWriter::isSymbolRefDifferenceFullyResolvedImpl(
projects / oota-llvm.git / blobdiff