[lld] 5ad2aae - [ELF] SharedFile::parse: move verdefIndex assignment outside of ctor. NFC

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2022-02-05T20:43:51-08:00
New Revision: 5ad2aae24474bb5366e84bfe27a5052185d856ce

URL: https://github.com/llvm/llvm-project/commit/5ad2aae24474bb5366e84bfe27a5052185d856ce
DIFF: https://github.com/llvm/llvm-project/commit/5ad2aae24474bb5366e84bfe27a5052185d856ce.diff

LOG: [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.

Added: 
    

Modified: 
    lld/ELF/InputFiles.cpp
    lld/ELF/Symbols.h

Removed: 
    


################################################################################
diff  --git a/lld/ELF/InputFiles.cpp b/lld/ELF/InputFiles.cpp
index 7b25617e52505..ebe4f99e84d0e 100644
--- a/lld/ELF/InputFiles.cpp
+++ b/lld/ELF/InputFiles.cpp
@@ -1530,9 +1530,11 @@ template <class ELFT> void SharedFile::parse() {
 
     uint32_t alignment = getAlignment<ELFT>(sections, sym);
     if (!(versyms[i] & VERSYM_HIDDEN)) {
-      symtab.addSymbol(SharedSymbol{*this, name, sym.getBinding(), sym.st_other,
-                                    sym.getType(), sym.st_value, sym.st_size,
-                                    alignment, idx});
+      auto *s = symtab.addSymbol(
+          SharedSymbol{*this, name, sym.getBinding(), sym.st_other,
+                       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
@@ -1552,9 +1554,11 @@ template <class ELFT> void SharedFile::parse() {
         reinterpret_cast<const Elf_Verdef *>(verdefs[idx])->getAux()->vda_name;
     versionedNameBuffer.clear();
     name = (name + "@" + verName).toStringRef(versionedNameBuffer);
-    symtab.addSymbol(SharedSymbol{*this, saver().save(name), sym.getBinding(),
-                                  sym.st_other, sym.getType(), sym.st_value,
-                                  sym.st_size, alignment, idx});
+    auto *s = symtab.addSymbol(
+        SharedSymbol{*this, saver().save(name), sym.getBinding(), sym.st_other,
+                     sym.getType(), sym.st_value, sym.st_size, alignment});
+    if (s->file == this)
+      s->verdefIndex = idx;
   }
 }
 

diff  --git a/lld/ELF/Symbols.h b/lld/ELF/Symbols.h
index d5946bd0271cf..271b0fadae23c 100644
--- a/lld/ELF/Symbols.h
+++ b/lld/ELF/Symbols.h
@@ -140,7 +140,7 @@ class Symbol {
   // True if the name contains '@'.
   uint8_t hasVersionSuffix : 1;
 
-  inline void replace(const Symbol &newSym);
+  inline void replace(const Symbol &other);
 
   bool includeInDynsym() const;
   uint8_t computeBinding() const;
@@ -388,10 +388,9 @@ class SharedSymbol : public Symbol {
 
   SharedSymbol(InputFile &file, StringRef name, uint8_t binding,
                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),
         size(size), alignment(alignment) {
-    this->verdefIndex = verdefIndex;
     exportDynamic = true;
     // GNU ifunc is a mechanism to allow user-supplied functions to
     // 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
 // 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.
-void Symbol::replace(const Symbol &newSym) {
+void Symbol::replace(const Symbol &other) {
   using llvm::ELF::STT_TLS;
 
   // 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
   // STT_TLS symbol, (b) a STT_TLS undefined symbol can be replaced by a
   // STT_NOTYPE lazy symbol.
-  if (symbolKind != PlaceholderKind && !newSym.isLazy() &&
-      (type == STT_TLS) != (newSym.type == STT_TLS) &&
+  if (symbolKind != PlaceholderKind && !other.isLazy() &&
+      (type == STT_TLS) != (other.type == STT_TLS) &&
       type != llvm::ELF::STT_NOTYPE)
     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;
-  memcpy(this, &newSym, newSym.getSymbolSize());
+  memcpy(this, &other, other.getSymbolSize());
 
   // old may be a placeholder. The referenced fields must be initialized in
   // SymbolTable::insert.