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[ELF] SharedFile::parse: move verdefIndex assignment outside of ctor. NFC 

SharedSymbol::SharedSymbol initializes verdefIndex and Symbol::replace
copies verdefIndex.

By move verdefIndex assignment outside of ctor, Symbol::replace can be changed
to not copy verdefIndex. This can be used to decrease work for for
ObjKind/BitcodeKind.
This commit is contained in:
Fangrui Song 2022-02-05 20:43:51 -08:00
parent 0719c43735
commit 5ad2aae244
2 changed files with 17 additions and 14 deletions
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16
lld/ELF/InputFiles.cpp
View File

@ -1530,9 +1530,11 @@ template <class ELFT> void SharedFile::parse() {
uint32_t alignment = getAlignment<ELFT>(sections, sym); uint32_t alignment = getAlignment<ELFT>(sections, sym);
if (!(versyms[i] & VERSYM_HIDDEN)) { if (!(versyms[i] & VERSYM_HIDDEN)) {
symtab.addSymbol(SharedSymbol{*this, name, sym.getBinding(), sym.st_other, auto *s = symtab.addSymbol(
sym.getType(), sym.st_value, sym.st_size, SharedSymbol{*this, name, sym.getBinding(), sym.st_other,
alignment, idx}); sym.getType(), sym.st_value, sym.st_size, alignment});
if (s->file == this)
s->verdefIndex = idx;
} }
// Also add the symbol with the versioned name to handle undefined symbols // Also add the symbol with the versioned name to handle undefined symbols
@ -1552,9 +1554,11 @@ template <class ELFT> void SharedFile::parse() {
reinterpret_cast<const Elf_Verdef *>(verdefs[idx])->getAux()->vda_name; reinterpret_cast<const Elf_Verdef *>(verdefs[idx])->getAux()->vda_name;
versionedNameBuffer.clear(); versionedNameBuffer.clear();
name = (name + "@" + verName).toStringRef(versionedNameBuffer); name = (name + "@" + verName).toStringRef(versionedNameBuffer);
symtab.addSymbol(SharedSymbol{*this, saver().save(name), sym.getBinding(), auto *s = symtab.addSymbol(
sym.st_other, sym.getType(), sym.st_value, SharedSymbol{*this, saver().save(name), sym.getBinding(), sym.st_other,
sym.st_size, alignment, idx}); sym.getType(), sym.st_value, sym.st_size, alignment});
if (s->file == this)
s->verdefIndex = idx;
} }
} }

15
lld/ELF/Symbols.h
View File

@ -140,7 +140,7 @@ public:
// True if the name contains '@'. // True if the name contains '@'.
uint8_t hasVersionSuffix : 1; uint8_t hasVersionSuffix : 1;
inline void replace(const Symbol &newSym); inline void replace(const Symbol &other);
bool includeInDynsym() const; bool includeInDynsym() const;
uint8_t computeBinding() const; uint8_t computeBinding() const;
@ -388,10 +388,9 @@ public:
SharedSymbol(InputFile &file, StringRef name, uint8_t binding, SharedSymbol(InputFile &file, StringRef name, uint8_t binding,
uint8_t stOther, uint8_t type, uint64_t value, uint64_t size, uint8_t stOther, uint8_t type, uint64_t value, uint64_t size,
uint32_t alignment, uint16_t verdefIndex) uint32_t alignment)
: Symbol(SharedKind, &file, name, binding, stOther, type), value(value), : Symbol(SharedKind, &file, name, binding, stOther, type), value(value),
size(size), alignment(alignment) { size(size), alignment(alignment) {
this->verdefIndex = verdefIndex;
exportDynamic = true; exportDynamic = true;
// GNU ifunc is a mechanism to allow user-supplied functions to // GNU ifunc is a mechanism to allow user-supplied functions to
// resolve PLT slot values at load-time. This is contrary to the // resolve PLT slot values at load-time. This is contrary to the
@ -559,7 +558,7 @@ size_t Symbol::getSymbolSize() const {
// replace() replaces "this" object with a given symbol by memcpy'ing // replace() replaces "this" object with a given symbol by memcpy'ing
// it over to "this". This function is called as a result of name // it over to "this". This function is called as a result of name
// resolution, e.g. to replace an undefind symbol with a defined symbol. // resolution, e.g. to replace an undefind symbol with a defined symbol.
void Symbol::replace(const Symbol &newSym) { void Symbol::replace(const Symbol &other) {
using llvm::ELF::STT_TLS; using llvm::ELF::STT_TLS;
// st_value of STT_TLS represents the assigned offset, not the actual address // st_value of STT_TLS represents the assigned offset, not the actual address
@ -569,14 +568,14 @@ void Symbol::replace(const Symbol &newSym) {
// exceptions: (a) a STT_NOTYPE lazy/undefined symbol can be replaced by a // exceptions: (a) a STT_NOTYPE lazy/undefined symbol can be replaced by a
// STT_TLS symbol, (b) a STT_TLS undefined symbol can be replaced by a // STT_TLS symbol, (b) a STT_TLS undefined symbol can be replaced by a
// STT_NOTYPE lazy symbol. // STT_NOTYPE lazy symbol.
if (symbolKind != PlaceholderKind && !newSym.isLazy() && if (symbolKind != PlaceholderKind && !other.isLazy() &&
(type == STT_TLS) != (newSym.type == STT_TLS) && (type == STT_TLS) != (other.type == STT_TLS) &&
type != llvm::ELF::STT_NOTYPE) type != llvm::ELF::STT_NOTYPE)
error("TLS attribute mismatch: " + toString(*this) + "\n>>> defined in " + error("TLS attribute mismatch: " + toString(*this) + "\n>>> defined in " +
toString(newSym.file) + "\n>>> defined in " + toString(file)); toString(other.file) + "\n>>> defined in " + toString(file));
Symbol old = *this; Symbol old = *this;
memcpy(this, &newSym, newSym.getSymbolSize()); memcpy(this, &other, other.getSymbolSize());
// old may be a placeholder. The referenced fields must be initialized in // old may be a placeholder. The referenced fields must be initialized in
// SymbolTable::insert. // SymbolTable::insert.