Revert "[llvm-objcopy] Add support for large indexes"
Not all build bots have unzip which I used in a test.
This reverts commit 0b1f26d39ea42dd3716b525fbc8c78d8c7bb4479.
llvm-svn: 326941
diff --git a/llvm/tools/llvm-objcopy/Object.cpp b/llvm/tools/llvm-objcopy/Object.cpp
index dc77fed..b3ad732 100644
--- a/llvm/tools/llvm-objcopy/Object.cpp
+++ b/llvm/tools/llvm-objcopy/Object.cpp
@@ -68,10 +68,6 @@
SectionVisitor::~SectionVisitor() {}
-void BinarySectionWriter::visit(const SectionIndexSection &Sec) {
- error("Cannot write symbol section index table '" + Sec.Name + "' ");
-}
-
void BinarySectionWriter::visit(const SymbolTableSection &Sec) {
error("Cannot write symbol table '" + Sec.Name + "' out to binary");
}
@@ -121,29 +117,6 @@
Visitor.visit(*this);
}
-template <class ELFT>
-void ELFSectionWriter<ELFT>::visit(const SectionIndexSection &Sec) {
- uint8_t *Buf = Out.getBufferStart() + Sec.Offset;
- auto *Indexes = reinterpret_cast<typename ELFT::Word *>(Buf);
- std::copy(std::begin(Sec.Indexes), std::end(Sec.Indexes), Indexes);
-}
-
-void SectionIndexSection::initialize(SectionTableRef SecTable) {
- Size = 0;
- setSymTab(SecTable.getSectionOfType<SymbolTableSection>(
- Link,
- "Link field value " + Twine(Link) + " in section " + Name + " is invalid",
- "Link field value " + Twine(Link) + " in section " + Name +
- " is not a symbol table"));
- Symbols->setShndxTable(this);
-}
-
-void SectionIndexSection::finalize() { Link = Symbols->Index; }
-
-void SectionIndexSection::accept(SectionVisitor &Visitor) const {
- Visitor.visit(*this);
-}
-
static bool isValidReservedSectionIndex(uint16_t Index, uint16_t Machine) {
switch (Index) {
case SHN_ABS:
@@ -162,12 +135,8 @@
return false;
}
-// Large indexes force us to clarify exactly what this function should do. This
-// function should return the proper value of st_shndx.
uint16_t Symbol::getShndx() const {
if (DefinedIn != nullptr) {
- if (DefinedIn->Index >= SHN_LORESERVE)
- return SHN_XINDEX;
return DefinedIn->Index;
}
switch (ShndxType) {
@@ -181,7 +150,6 @@
case SYMBOL_HEXAGON_SCOMMON_2:
case SYMBOL_HEXAGON_SCOMMON_4:
case SYMBOL_HEXAGON_SCOMMON_8:
- case SYMBOL_XINDEX:
return static_cast<uint16_t>(ShndxType);
}
llvm_unreachable("Symbol with invalid ShndxType encountered");
@@ -196,12 +164,12 @@
Sym.Binding = Bind;
Sym.Type = Type;
Sym.DefinedIn = DefinedIn;
- if (DefinedIn != nullptr)
- DefinedIn->HasSymbol = true;
- if (Shndx >= SHN_LORESERVE)
- Sym.ShndxType = static_cast<SymbolShndxType>(Shndx);
- else
- Sym.ShndxType = SYMBOL_SIMPLE_INDEX;
+ if (DefinedIn == nullptr) {
+ if (Shndx >= SHN_LORESERVE)
+ Sym.ShndxType = static_cast<SymbolShndxType>(Shndx);
+ else
+ Sym.ShndxType = SYMBOL_SIMPLE_INDEX;
+ }
Sym.Value = Value;
Sym.Visibility = Visibility;
Sym.Size = Sz;
@@ -211,9 +179,6 @@
}
void SymbolTableSection::removeSectionReferences(const SectionBase *Sec) {
- if (SectionIndexTable == Sec)
- SectionIndexTable = nullptr;
-
if (SymbolNames == Sec) {
error("String table " + SymbolNames->Name +
" cannot be removed because it is referenced by the symbol table " +
@@ -247,7 +212,6 @@
void SymbolTableSection::initialize(SectionTableRef SecTable) {
Size = 0;
-
setStrTab(SecTable.getSectionOfType<StringTableSection>(
Link,
"Symbol table has link index of " + Twine(Link) +
@@ -271,17 +235,7 @@
Info = MaxLocalIndex + 1;
}
-void SymbolTableSection::prepareForLayout() {
- // Add all potential section indexes before file layout so that the section
- // index section has the approprite size.
- if (SectionIndexTable != nullptr) {
- for (const auto &Sym : Symbols) {
- if (Sym->DefinedIn != nullptr && Sym->DefinedIn->Index >= SHN_LORESERVE)
- SectionIndexTable->addIndex(Sym->DefinedIn->Index);
- else
- SectionIndexTable->addIndex(SHN_UNDEF);
- }
- }
+void SymbolTableSection::addSymbolNames() {
// Add all of our strings to SymbolNames so that SymbolNames has the right
// size before layout is decided.
for (auto &Sym : Symbols)
@@ -584,32 +538,12 @@
void ELFBuilder<ELFT>::initSymbolTable(SymbolTableSection *SymTab) {
const Elf_Shdr &Shdr = *unwrapOrError(ElfFile.getSection(SymTab->Index));
StringRef StrTabData = unwrapOrError(ElfFile.getStringTableForSymtab(Shdr));
- ArrayRef<Elf_Word> ShndxData;
- auto Symbols = unwrapOrError(ElfFile.symbols(&Shdr));
- for (const auto &Sym : Symbols) {
+ for (const auto &Sym : unwrapOrError(ElfFile.symbols(&Shdr))) {
SectionBase *DefSection = nullptr;
StringRef Name = unwrapOrError(Sym.getName(StrTabData));
- if (Sym.st_shndx == SHN_XINDEX) {
- if (SymTab->getShndxTable() == nullptr)
- error("Symbol '" + Name +
- "' has index SHN_XINDEX but no SHT_SYMTAB_SHNDX section exists.");
- if (ShndxData.data() == nullptr) {
- const Elf_Shdr &ShndxSec =
- *unwrapOrError(ElfFile.getSection(SymTab->getShndxTable()->Index));
- ShndxData = unwrapOrError(
- ElfFile.template getSectionContentsAsArray<Elf_Word>(&ShndxSec));
- if (ShndxData.size() != Symbols.size())
- error("Symbol section index table does not have the same number of "
- "entries as the symbol table.");
- }
- auto Index = ShndxData[&Sym - Symbols.begin()];
- DefSection = Obj.sections().getSection(
- Index,
- "Symbol '" + Name + "' is defined in invalid section with index " +
- Twine(Index));
- } else if (Sym.st_shndx >= SHN_LORESERVE) {
+ if (Sym.st_shndx >= SHN_LORESERVE) {
if (!isValidReservedSectionIndex(Sym.st_shndx, Obj.Machine)) {
error(
"Symbol '" + Name +
@@ -649,14 +583,14 @@
}
}
-SectionBase *SectionTableRef::getSection(uint32_t Index, Twine ErrMsg) {
+SectionBase *SectionTableRef::getSection(uint16_t Index, Twine ErrMsg) {
if (Index == SHN_UNDEF || Index > Sections.size())
error(ErrMsg);
return Sections[Index - 1].get();
}
template <class T>
-T *SectionTableRef::getSectionOfType(uint32_t Index, Twine IndexErrMsg,
+T *SectionTableRef::getSectionOfType(uint16_t Index, Twine IndexErrMsg,
Twine TypeErrMsg) {
if (T *Sec = dyn_cast<T>(getSection(Index, IndexErrMsg)))
return Sec;
@@ -700,11 +634,6 @@
Obj.SymbolTable = &SymTab;
return SymTab;
}
- case SHT_SYMTAB_SHNDX: {
- auto &ShndxSection = Obj.addSection<SectionIndexSection>();
- Obj.SectionIndexTable = &ShndxSection;
- return ShndxSection;
- }
case SHT_NOBITS:
return Obj.addSection<Section>(Data);
default:
@@ -735,10 +664,6 @@
Sec.Index = Index++;
}
- // If we have a SectionIndexTable we need to initialize it before the symbol
- // table because the symbol table will need it to properly read in symbols.
- if (Obj.SectionIndexTable)
- Obj.SectionIndexTable->initialize(Obj.sections());
// Now that all of the sections have been added we can fill out some extra
// details about symbol tables. We need the symbol table filled out before
// any relocations.
@@ -779,16 +704,12 @@
readSectionHeaders();
readProgramHeaders();
- uint32_t ShstrIndex = Ehdr.e_shstrndx;
- if (ShstrIndex == SHN_XINDEX)
- ShstrIndex = unwrapOrError(ElfFile.getSection(0))->sh_link;
-
Obj.SectionNames =
Obj.sections().template getSectionOfType<StringTableSection>(
- ShstrIndex,
- "e_shstrndx field value " + Twine(ShstrIndex) +
+ Ehdr.e_shstrndx,
+ "e_shstrndx field value " + Twine(Ehdr.e_shstrndx) +
" in elf header " + " is invalid",
- "e_shstrndx field value " + Twine(ShstrIndex) +
+ "e_shstrndx field value " + Twine(Ehdr.e_shstrndx) +
" in elf header " + " is not a string table");
}
@@ -859,27 +780,8 @@
Ehdr.e_shentsize = sizeof(Elf_Shdr);
if (WriteSectionHeaders) {
Ehdr.e_shoff = Obj.SHOffset;
- // """
- // If the number of sections is greater than or equal to
- // SHN_LORESERVE (0xff00), this member has the value zero and the actual
- // number of section header table entries is contained in the sh_size field
- // of the section header at index 0.
- // """
- auto Shnum = size(Obj.sections()) + 1;
- if (Shnum >= SHN_LORESERVE)
- Ehdr.e_shnum = 0;
- else
- Ehdr.e_shnum = Shnum;
- // """
- // If the section name string table section index is greater than or equal
- // to SHN_LORESERVE (0xff00), this member has the value SHN_XINDEX (0xffff)
- // and the actual index of the section name string table section is
- // contained in the sh_link field of the section header at index 0.
- // """
- if (Obj.SectionNames->Index >= SHN_LORESERVE)
- Ehdr.e_shstrndx = SHN_XINDEX;
- else
- Ehdr.e_shstrndx = Obj.SectionNames->Index;
+ Ehdr.e_shnum = size(Obj.sections()) + 1;
+ Ehdr.e_shstrndx = Obj.SectionNames->Index;
} else {
Ehdr.e_shoff = 0;
Ehdr.e_shnum = 0;
@@ -902,17 +804,8 @@
Shdr.sh_flags = 0;
Shdr.sh_addr = 0;
Shdr.sh_offset = 0;
- // See writeEhdr for why we do this.
- auto Shnum = size(Obj.sections()) + 1;
- if (Shnum >= SHN_LORESERVE) {
- Shdr.sh_size = Shnum;
- } else
- Shdr.sh_size = 0;
- // See writeEhdr for why we do this.
- if (Obj.SectionNames != nullptr && Obj.SectionNames->Index >= SHN_LORESERVE) {
- Shdr.sh_link = Obj.SectionNames->Index;
- } else
- Shdr.sh_link = 0;
+ Shdr.sh_size = 0;
+ Shdr.sh_link = 0;
Shdr.sh_info = 0;
Shdr.sh_addralign = 0;
Shdr.sh_entsize = 0;
@@ -940,10 +833,9 @@
});
if (SymbolTable != nullptr && ToRemove(*SymbolTable))
SymbolTable = nullptr;
- if (SectionNames != nullptr && ToRemove(*SectionNames))
+ if (SectionNames != nullptr && ToRemove(*SectionNames)) {
SectionNames = nullptr;
- if (SectionIndexTable != nullptr && ToRemove(*SectionIndexTable))
- SectionIndexTable = nullptr;
+ }
// Now make sure there are no remaining references to the sections that will
// be removed. Sometimes it is impossible to remove a reference so we emit
// an error here instead.
@@ -1105,57 +997,16 @@
error("Cannot write section header table because section header string "
"table was removed.");
- Obj.sortSections();
- // We need to assign indexes before we perform layout because we need to know
- // if we need large indexes or not. We can assign indexes first and check as
- // we go to see if we will actully need large indexes.
- bool NeedsLargeIndexes = false;
- if (size(Obj.sections()) >= SHN_LORESERVE) {
- uint64_t Index = SHN_LORESERVE;
- auto Sections = Obj.sections();
- auto LargeIndexSections =
- make_range(Sections.begin() + SHN_LORESERVE, Sections.end());
- for (auto &Sec : LargeIndexSections) {
- Sec.Index = Index++;
- if (Sec.HasSymbol) {
- NeedsLargeIndexes = true;
- break;
- }
- }
- // TODO: handle case where only one section needs the large index table but
- // only needs it because the large index table hasn't been removed yet.
- }
-
- if (NeedsLargeIndexes) {
- // This means we definitely need to have a section index table but if
- // already have one then we should use it instead of making a new one.
- if (Obj.SymbolTable != nullptr && Obj.SectionIndexTable == nullptr) {
- auto &Shndx = Obj.addSection<SectionIndexSection>();
- Obj.SymbolTable->setShndxTable(&Shndx);
- Shndx.setSymTab(Obj.SymbolTable);
- }
- } else {
- // Since we don't need SectionIndexTable we should remove it and all
- // references to it.
- if (Obj.SectionIndexTable != nullptr) {
- Obj.removeSections(
- [](const SectionBase &Sec) { return Sec.Type == SHT_SYMTAB_SHNDX; });
- }
- }
-
- // Make sure we add the names of all the sections. Importantly this must be
- // done after we decide to add or remove SectionIndexes.
+ // Make sure we add the names of all the sections.
if (Obj.SectionNames != nullptr)
for (const auto &Section : Obj.sections()) {
Obj.SectionNames->addString(Section.Name);
}
-
- // The symbol table does not update all other sections on update. For
- // instance symbol names are not added as new symbols are added. This means
- // that some sections, like .strtab, don't yet have their final size.
+ // Make sure we add the names of all the symbols.
if (Obj.SymbolTable != nullptr)
- Obj.SymbolTable->prepareForLayout();
+ Obj.SymbolTable->addSymbolNames();
+ Obj.sortSections();
assignOffsets();
// Finalize SectionNames first so that we can assign name indexes.