[PATCH] D49547: [ELF] - Get rid of postThunkContents().

[George Rimar via Phabricator via llvm-commits]

grimar created this revision.
grimar added reviewers: ruiu, psmith.
Herald added subscribers: arichardson, emaste.
Herald added a reviewer: espindola.

It turns out that postThunkContents() is only used for
sorting symbols in `.symtab`.

Though we can instead move the logic to `finalizeContents`,
postpone calling it and then get rid of `postThunkContents()` completely.


https://reviews.llvm.org/D49547

Files:
  ELF/SyntheticSections.cpp
  ELF/SyntheticSections.h
  ELF/Writer.cpp


Index: ELF/Writer.cpp
===================================================================
--- ELF/Writer.cpp
+++ ELF/Writer.cpp
@@ -1639,12 +1639,12 @@
   // Dynamic section must be the last one in this list and dynamic
   // symbol table section (DynSymTab) must be the first one.
   applySynthetic(
-      {InX::DynSymTab,   InX::Bss,         InX::BssRelRo,     InX::GnuHashTab,
-       InX::HashTab,     InX::SymTab,      InX::ShStrTab,     InX::StrTab,
-       In<ELFT>::VerDef, InX::DynStrTab,   InX::Got,          InX::MipsGot,
-       InX::IgotPlt,     InX::GotPlt,      InX::RelaDyn,      InX::RelrDyn,
-       InX::RelaIplt,    InX::RelaPlt,     InX::Plt,          InX::Iplt,
-       InX::EhFrameHdr,  In<ELFT>::VerSym, In<ELFT>::VerNeed, InX::Dynamic},
+      {InX::DynSymTab,   InX::Bss,          InX::BssRelRo, InX::GnuHashTab,
+       InX::HashTab,     InX::ShStrTab,     InX::StrTab,   In<ELFT>::VerDef,
+       InX::DynStrTab,   InX::Got,          InX::MipsGot,  InX::IgotPlt,
+       InX::GotPlt,      InX::RelaDyn,      InX::RelrDyn,  InX::RelaIplt,
+       InX::RelaPlt,     InX::Plt,          InX::Iplt,     InX::EhFrameHdr,
+       In<ELFT>::VerSym, In<ELFT>::VerNeed, InX::Dynamic},
       [](SyntheticSection *SS) { SS->finalizeContents(); });
 
   if (!Script->HasSectionsCommand && !Config->Relocatable)
@@ -1684,7 +1684,7 @@
 
   // createThunks may have added local symbols to the static symbol table
   applySynthetic({InX::SymTab},
-                 [](SyntheticSection *SS) { SS->postThunkContents(); });
+                 [](SyntheticSection *SS) { SS->finalizeContents(); });
 
   // Fill other section headers. The dynamic table is finalized
   // at the end because some tags like RELSZ depend on result
Index: ELF/SyntheticSections.h
===================================================================
--- ELF/SyntheticSections.h
+++ ELF/SyntheticSections.h
@@ -50,8 +50,6 @@
   // If the section has the SHF_ALLOC flag and the size may be changed if
   // thunks are added, update the section size.
   virtual bool updateAllocSize() { return false; }
-  // If any additional finalization of contents are needed post thunk creation.
-  virtual void postThunkContents() {}
   virtual bool empty() const { return false; }
 
   static bool classof(const SectionBase *D) {
@@ -561,14 +559,15 @@
 public:
   SymbolTableBaseSection(StringTableSection &StrTabSec);
   void finalizeContents() override;
-  void postThunkContents() override;
   size_t getSize() const override { return getNumSymbols() * Entsize; }
   void addSymbol(Symbol *Sym);
   unsigned getNumSymbols() const { return Symbols.size() + 1; }
   size_t getSymbolIndex(Symbol *Sym);
   ArrayRef<SymbolTableEntry> getSymbols() const { return Symbols; }
 
 protected:
+  void sortSymTabSymbols();
+
   // A vector of symbols and their string table offsets.
   std::vector<SymbolTableEntry> Symbols;
 
Index: ELF/SyntheticSections.cpp
===================================================================
--- ELF/SyntheticSections.cpp
+++ ELF/SyntheticSections.cpp
@@ -1819,8 +1819,10 @@
 void SymbolTableBaseSection::finalizeContents() {
   getParent()->Link = StrTabSec.getParent()->SectionIndex;
 
-  if (this->Type != SHT_DYNSYM)
+  if (this->Type != SHT_DYNSYM) {
+    sortSymTabSymbols();
     return;
+  }
 
   // If it is a .dynsym, there should be no local symbols, but we need
   // to do a few things for the dynamic linker.
@@ -1848,9 +1850,7 @@
 // Aside from above, we put local symbols in groups starting with the STT_FILE
 // symbol. That is convenient for purpose of identifying where are local symbols
 // coming from.
-void SymbolTableBaseSection::postThunkContents() {
-  assert(this->Type == SHT_SYMTAB);
-
+void SymbolTableBaseSection::sortSymTabSymbols() {
   // Move all local symbols before global symbols.
   auto E = std::stable_partition(
       Symbols.begin(), Symbols.end(), [](const SymbolTableEntry &S) {


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