[lld][ELF] (no testable functionality change) resize the number of entries in the string table for static linking

llvm-svn: 180691

lld/lib/ReaderWriter/ELF/OutputELFWriter.h

@@ -58,7 +58,7 @@ protected:
 
   // Build the atom to address map, this has to be called
   // before applying relocations
-  virtual void buildAtomToAddressMap();
+  virtual void buildAtomToAddressMap(const File &file);
 
   // Build the symbol table for static linking
   virtual void buildStaticSymbolTable(const File &file);
@@ -167,14 +167,25 @@ void OutputELFWriter<ELFT>::buildDynamicSymbolTable(const File &file) {
   _dynamicSymbolTable->addSymbolsToHashTable();
 }
 
-template <class ELFT> void OutputELFWriter<ELFT>::buildAtomToAddressMap() {
+template <class ELFT>
+void OutputELFWriter<ELFT>::buildAtomToAddressMap(const File &file) {
+  int64_t totalAbsAtoms = _layout->absoluteAtoms().size();
+  int64_t totalUndefinedAtoms = file.undefined().size();
+  int64_t totalDefinedAtoms = 0;
   for (auto sec : _layout->sections())
-    if (auto section = dyn_cast<AtomSection<ELFT>>(sec))
+    if (auto section = dyn_cast<AtomSection<ELFT> >(sec)) {
+      totalDefinedAtoms += section->atoms().size();
       for (const auto &atom : section->atoms())
         _atomToAddressMap[atom->_atom] = atom->_virtualAddr;
+    }
   // build the atomToAddressMap that contains absolute symbols too
   for (auto &atom : _layout->absoluteAtoms())
     _atomToAddressMap[atom->_atom] = atom->_virtualAddr;
+
+  // Set the total number of atoms in the symbol table, so that appropriate
+  // resizing of the string table can be done
+  _symtab->setNumEntries(totalDefinedAtoms + totalAbsAtoms +
+                         totalUndefinedAtoms);
 }
 
 template<class ELFT>
@@ -287,7 +298,7 @@ error_code OutputELFWriter<ELFT>::buildOutput(const File &file) {
   finalizeDefaultAtomValues();
 
   // Build the Atom To Address map for applying relocations
-  buildAtomToAddressMap();
+  buildAtomToAddressMap(file);
 
   // Create symbol table and section string table
   buildStaticSymbolTable(file);

lld/lib/ReaderWriter/ELF/SectionChunks.h

@@ -510,6 +510,10 @@ public:
 
   virtual void write(ELFWriter *writer, llvm::FileOutputBuffer &buffer);
 
+  inline void setNumEntries(int64_t numEntries) {
+    _stringMap.resize(numEntries);
+  }
+
 private:
   std::vector<StringRef> _strings;
 
@@ -597,8 +601,15 @@ class SymbolTable : public Section<ELFT> {
 public:
   SymbolTable(const ELFTargetInfo &ti, const char *str, int32_t order);
 
-  void addSymbol(const Atom *atom, int32_t sectionIndex,
-                 uint64_t addr = 0, const AtomLayout *layout=nullptr);
+  /// \brief set the number of entries that would exist in the symbol
+  /// table for the current link
+  void setNumEntries(int64_t numEntries) const {
+    if (_stringSection)
+      _stringSection->setNumEntries(numEntries);
+  }
+
+  void addSymbol(const Atom *atom, int32_t sectionIndex, uint64_t addr = 0,
+                 const AtomLayout *layout = nullptr);
 
   /// \brief Get the symbol table index for an Atom. If it's not in the symbol
   /// table, return STN_UNDEF.