From 4235ba32f2610ee2ed1e0c4bfca5c67835e9f97d Mon Sep 17 00:00:00 2001
From: Sean Silva <silvas@purdue.edu>
Date: Fri, 21 Jun 2013 00:27:50 +0000
Subject: [yaml2obj][ELF] Don't explicitly set `Binding` with STB_*

Instead, just have 3 sub-lists, one for each of
{STB_LOCAL,STB_GLOBAL,STB_WEAK}.

This allows us to be a lot more explicit w.r.t. the symbol ordering in
the object file, because if we allowed explicitly setting the STB_*
`Binding` key for the symbol, then we might have ended up having to
shuffle STB_LOCAL symbols to the front of the list, which is likely to
cause confusion and potential for error.

Also, this new approach is simpler ;)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184506 91177308-0d34-0410-b5e6-96231b3b80d8
---
 tools/yaml2obj/yaml2elf.cpp | 57 ++++++++++++++++++++++++++-------------------
 1 file changed, 33 insertions(+), 24 deletions(-)

(limited to 'tools/yaml2obj')

diff --git a/tools/yaml2obj/yaml2elf.cpp b/tools/yaml2obj/yaml2elf.cpp
index a8eeeeacf1..cd6df144b7 100644
--- a/tools/yaml2obj/yaml2elf.cpp
+++ b/tools/yaml2obj/yaml2elf.cpp
@@ -168,9 +168,34 @@ public:
 };
 } // end anonymous namespace
 
-// FIXME: This function is hideous. The hideous ELF type names are hideous.
-// Factor the ELF output into a class (templated on ELFT) and share some
-// typedefs.
+// FIXME: At this point it is fairly clear that we need to refactor these
+// static functions into methods of a class sharing some typedefs. These
+// ELF type names are insane.
+template <class ELFT,
+          class Elf_Sym = typename object::ELFObjectFile<ELFT>::Elf_Sym>
+static void addSymbols(const std::vector<ELFYAML::Symbol> &Symbols,
+                       ELFState<ELFT> &State, std::vector<Elf_Sym> &Syms,
+                       unsigned SymbolBinding) {
+  for (unsigned i = 0, e = Symbols.size(); i != e; ++i) {
+    const ELFYAML::Symbol &Sym = Symbols[i];
+    Elf_Sym Symbol;
+    zero(Symbol);
+    if (!Sym.Name.empty())
+      Symbol.st_name = State.getStringTable().addString(Sym.Name);
+    Symbol.setBindingAndType(SymbolBinding, Sym.Type);
+    unsigned Index;
+    if (State.getSN2I().lookupSection(Sym.Section, Index)) {
+      errs() << "error: Unknown section referenced: '" << Sym.Section
+             << "' by YAML symbol " << Sym.Name << ".\n";
+      exit(1);
+    }
+    Symbol.st_shndx = Index;
+    Symbol.st_value = Sym.Value;
+    Symbol.st_size = Sym.Size;
+    Syms.push_back(Symbol);
+  }
+}
+
 template <class ELFT>
 static void handleSymtabSectionHeader(
     const ELFYAML::Section &Sec, ELFState<ELFT> &State,
@@ -180,9 +205,8 @@ static void handleSymtabSectionHeader(
   // TODO: Ensure that a manually specified `Link` field is diagnosed as an
   // error for SHT_SYMTAB.
   SHeader.sh_link = State.getDotStrTabSecNo();
-  // TODO: Once we handle symbol binding, this should be one greater than
-  // symbol table index of the last local symbol.
-  SHeader.sh_info = 0;
+  // One greater than symbol table index of the last local symbol.
+  SHeader.sh_info = Sec.Symbols.Local.size() + 1;
   SHeader.sh_entsize = sizeof(Elf_Sym);
 
   std::vector<Elf_Sym> Syms;
@@ -192,24 +216,9 @@ static void handleSymtabSectionHeader(
     zero(Sym);
     Syms.push_back(Sym);
   }
-  for (unsigned i = 0, e = Sec.Symbols.size(); i != e; ++i) {
-    const ELFYAML::Symbol &Sym = Sec.Symbols[i];
-    Elf_Sym Symbol;
-    zero(Symbol);
-    if (!Sym.Name.empty())
-      Symbol.st_name = State.getStringTable().addString(Sym.Name);
-    Symbol.setBindingAndType(Sym.Binding, Sym.Type);
-    unsigned Index;
-    if (State.getSN2I().lookupSection(Sym.Section, Index)) {
-      errs() << "error: Unknown section referenced: '" << Sym.Section
-             << "' by YAML symbol " << Sym.Name << ".\n";
-      exit(1);
-    }
-    Symbol.st_shndx = Index;
-    Symbol.st_value = Sym.Value;
-    Symbol.st_size = Sym.Size;
-    Syms.push_back(Symbol);
-  }
+  addSymbols(Sec.Symbols.Local, State, Syms, ELF::STB_LOCAL);
+  addSymbols(Sec.Symbols.Global, State, Syms, ELF::STB_GLOBAL);
+  addSymbols(Sec.Symbols.Weak, State, Syms, ELF::STB_WEAK);
 
   ContiguousBlobAccumulator &CBA = State.getSectionContentAccum();
   SHeader.sh_offset = CBA.currentOffset();
-- 
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