Subzero: Fix symbol name mangling. Make flags global.

src/IceELFSection.h

Index: src/IceELFSection.h
diff --git a/src/IceELFSection.h b/src/IceELFSection.h
index 67e8483cd5be52f630531357e5b1fccd6695c64a..28fb6b01aa220aed815561d0ee6bf0c410d35549 100644
--- a/src/IceELFSection.h
+++ b/src/IceELFSection.h
@@ -240,8 +240,7 @@ public:
   size_t getSectionDataSize() const;
 
   template <bool IsELF64>
-  void writeData(const GlobalContext &Ctx, ELFStreamer &Str,
-                 const ELFSymbolTableSection *SymTab);
+  void writeData(ELFStreamer &Str, const ELFSymbolTableSection *SymTab);
 
   bool isRela() const { return Header.sh_type == SHT_RELA; }
 
@@ -348,7 +347,7 @@ void ELFSymbolTableSection::writeSymbolMap(ELFStreamer &Str,
 }
 
 template <bool IsELF64>
-void ELFRelocationSection::writeData(const GlobalContext &Ctx, ELFStreamer &Str,
+void ELFRelocationSection::writeData(ELFStreamer &Str,
                                      const ELFSymbolTableSection *SymTab) {
   for (const AssemblerFixup &Fixup : Fixups) {
     const ELFSym *Symbol;
@@ -356,7 +355,7 @@ void ELFRelocationSection::writeData(const GlobalContext &Ctx, ELFStreamer &Str,
       Symbol = SymTab->getNullSymbol();
     } else {
       constexpr Assembler *Asm = nullptr;
-      IceString Name = Fixup.symbol(&Ctx, Asm);
+      const IceString Name = Fixup.symbol(Asm);

[John, 2016/03/06 22:39:38]

Are you missing a reference here?

[Jim Stichnoth, 2016/03/07 00:03:10]

You mean like "const IceString &Name"?  The symbol() method constructs a new
string on the stack and returns it, so a reference won't do.

[John, 2016/03/07 16:41:08]

And that's why I would standardize into **never** returning string references.
It is weird that some methods return references while others return new objects.

Note. C++ guarantees that the returned object will be alive until the reference
to it goes out of scope -- it won't dangle!

#include <iostream>
#include <memory>

class Foo {
public:
  Foo(const Foo &) = default;
  ~Foo() { std::cerr << "Foo::~Foo()" "\n"; }
  static Foo create() { return Foo(); }

private:
  Foo() { std::cerr << "Foo::Foo()" "\n"; }
};

int main(int argc, char* argv[]) {
  const Foo &F = Foo::create();
  std::cerr << "before return." "\n";
  return 0;
}

prints:

Foo::Foo()
before return.
Foo::~Foo()

       Symbol = SymTab->findSymbol(Name);
       if (!Symbol)
         llvm::report_fatal_error(Name + ": Missing symbol mentioned in reloc");