[lld] r266317 - [ELF] - Refactoring of end/edata/etext implementation.

[George Rimar via llvm-commits]

Author: grimar
Date: Thu Apr 14 09:37:59 2016
New Revision: 266317

URL: http://llvm.org/viewvc/llvm-project?rev=266317&view=rev
Log:
[ELF] - Refactoring of end/edata/etext implementation.

Minor refactoring of how end/edata/etext symbols are handled.

Differential revision: http://reviews.llvm.org/D19109

Modified:
    lld/trunk/ELF/Symbols.h
    lld/trunk/ELF/Writer.cpp

Modified: lld/trunk/ELF/Symbols.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Symbols.h?rev=266317&r1=266316&r2=266317&view=diff
==============================================================================
--- lld/trunk/ELF/Symbols.h (original)
+++ lld/trunk/ELF/Symbols.h Thu Apr 14 09:37:59 2016
@@ -390,17 +390,16 @@ private:
 // Some linker-generated symbols need to be created as
 // DefinedRegular symbols.
 template <class ELFT> struct ElfSym {
+  typedef std::pair<DefinedRegular<ELFT> *, DefinedRegular<ELFT> *> SymPair;
+
   // The content for _etext and etext symbols.
-  static DefinedRegular<ELFT> *Etext;
-  static DefinedRegular<ELFT> *Etext2;
+  static SymPair Etext;
 
   // The content for _edata and edata symbols.
-  static DefinedRegular<ELFT> *Edata;
-  static DefinedRegular<ELFT> *Edata2;
+  static SymPair Edata;
 
   // The content for _end and end symbols.
-  static DefinedRegular<ELFT> *End;
-  static DefinedRegular<ELFT> *End2;
+  static SymPair End;
 
   // The content for _gp symbol for MIPS target.
   static SymbolBody *MipsGp;
@@ -414,12 +413,10 @@ template <class ELFT> struct ElfSym {
   static SymbolBody *RelaIpltEnd;
 };
 
-template <class ELFT> DefinedRegular<ELFT> *ElfSym<ELFT>::Etext;
-template <class ELFT> DefinedRegular<ELFT> *ElfSym<ELFT>::Etext2;
-template <class ELFT> DefinedRegular<ELFT> *ElfSym<ELFT>::Edata;
-template <class ELFT> DefinedRegular<ELFT> *ElfSym<ELFT>::Edata2;
-template <class ELFT> DefinedRegular<ELFT> *ElfSym<ELFT>::End;
-template <class ELFT> DefinedRegular<ELFT> *ElfSym<ELFT>::End2;
+template <class ELFT> typename ElfSym<ELFT>::SymPair ElfSym<ELFT>::Etext;
+template <class ELFT> typename ElfSym<ELFT>::SymPair ElfSym<ELFT>::Edata;
+template <class ELFT> typename ElfSym<ELFT>::SymPair ElfSym<ELFT>::End;
+
 template <class ELFT> SymbolBody *ElfSym<ELFT>::MipsGp;
 template <class ELFT> SymbolBody *ElfSym<ELFT>::MipsLocalGp;
 template <class ELFT> SymbolBody *ElfSym<ELFT>::MipsGpDisp;

Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=266317&r1=266316&r2=266317&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Thu Apr 14 09:37:59 2016
@@ -1102,9 +1102,8 @@ template <class ELFT> void Writer<ELFT>:
   if (!isOutputDynamic())
     Symtab.addIgnored("__tls_get_addr");
 
-  auto Define = [this](StringRef S, DefinedRegular<ELFT> *&Sym,
-                       DefinedRegular<ELFT> *&Sym2) {
-    Sym = Symtab.addIgnored(S, STV_DEFAULT);
+  auto Define = [this](StringRef S, ElfSym<ELFT>::SymPair &Sym) {
+    Sym.first = Symtab.addIgnored(S, STV_DEFAULT);
 
     // The name without the underscore is not a reserved name,
     // so it is defined only when there is a reference against it.
@@ -1112,12 +1111,12 @@ template <class ELFT> void Writer<ELFT>:
     S = S.substr(1);
     if (SymbolBody *B = Symtab.find(S))
       if (B->isUndefined())
-        Sym2 = Symtab.addAbsolute(S, STV_DEFAULT);
+        Sym.second = Symtab.addAbsolute(S, STV_DEFAULT);
   };
 
-  Define("_end", ElfSym<ELFT>::End, ElfSym<ELFT>::End2);
-  Define("_etext", ElfSym<ELFT>::Etext, ElfSym<ELFT>::Etext2);
-  Define("_edata", ElfSym<ELFT>::Edata, ElfSym<ELFT>::Edata2);
+  Define("_end", ElfSym<ELFT>::End);
+  Define("_etext", ElfSym<ELFT>::Etext);
+  Define("_edata", ElfSym<ELFT>::Edata);
 }
 
 // Sort input sections by section name suffixes for
@@ -1645,6 +1644,14 @@ static uint16_t getELFType() {
   return ET_EXEC;
 }
 
+template <class ELFT, class SymPair, class uintX_t>
+static void assignSymValue(SymPair &Sym, uintX_t Val) {
+  if (Sym.first)
+    Sym.first->Value = Val;
+  if (Sym.second)
+    Sym.second->Value = Val;
+}
+
 // This function is called after we have assigned address and size
 // to each section. This function fixes some predefined absolute
 // symbol values that depend on section address and size.
@@ -1656,24 +1663,13 @@ template <class ELFT> void Writer<ELFT>:
     Elf_Phdr &H = P.H;
     if (H.p_type != PT_LOAD)
       continue;
-    uintX_t Val = H.p_vaddr + H.p_memsz;
-    if (ElfSym<ELFT>::End)
-      ElfSym<ELFT>::End->Value = Val;
-    if (ElfSym<ELFT>::End2)
-      ElfSym<ELFT>::End2->Value = Val;
-
-    Val = H.p_vaddr + H.p_filesz;
-    if (H.p_flags & PF_W) {
-      if (ElfSym<ELFT>::Edata)
-        ElfSym<ELFT>::Edata->Value = Val;
-      if (ElfSym<ELFT>::Edata2)
-        ElfSym<ELFT>::Edata2->Value = Val;
-    } else {
-      if (ElfSym<ELFT>::Etext)
-        ElfSym<ELFT>::Etext->Value = Val;
-      if (ElfSym<ELFT>::Etext2)
-        ElfSym<ELFT>::Etext2->Value = Val;
-    }
+    assignSymValue<ELFT>(ElfSym<ELFT>::End, H.p_vaddr + H.p_memsz);
+
+    uintX_t Val = H.p_vaddr + H.p_filesz;
+    if (H.p_flags & PF_W)
+      assignSymValue<ELFT>(ElfSym<ELFT>::Edata, Val);
+    else
+      assignSymValue<ELFT>(ElfSym<ELFT>::Etext, Val);
   }
 }