[PATCH] D33680: [ELF] - Resolve references properly when using .symver directive

[Rafael Avila de Espindola via llvm-commits]

George Rimar via Phabricator <reviews at reviews.llvm.org> writes:

> Index: test/ELF/version-script-symver.s
> ===================================================================
> --- test/ELF/version-script-symver.s
> +++ test/ELF/version-script-symver.s
> @@ -0,0 +1,11 @@
> +# REQUIRES: x86
> +
> +# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
> +# RUN: echo "VERSION { global: *; };" > %t.map
> +# RUN: ld.lld %t.o --version-script %t.map -o %t

You don't need the version script, no?

> Index: test/ELF/version-script-symver-err.s
> ===================================================================
> --- test/ELF/version-script-symver-err.s
> +++ test/ELF/version-script-symver-err.s
> @@ -0,0 +1,16 @@
> +# REQUIRES: x86
> +
> +# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
> +# RUN: echo "VERSION { global: *; };" > %t.map
> +# RUN: not ld.lld %t.o --version-script %t.map -o %t 2>&1 | FileCheck %s

Same here, the version script should not be necessary.

> Index: ELF/Symbols.cpp
> ===================================================================
> --- ELF/Symbols.cpp
> +++ ELF/Symbols.cpp
> @@ -13,6 +13,7 @@
>  #include "InputSection.h"
>  #include "OutputSections.h"
>  #include "Strings.h"
> +#include "SymbolTable.h"
>  #include "SyntheticSections.h"
>  #include "Target.h"
>  #include "Writer.h"
> @@ -220,6 +221,21 @@
>    return nullptr;
>  }
>  
> +static void resolve(StringRef Name, Symbol *Sym) {
> +  switch (Config->EKind) {
> +  case ELF32LEKind:
> +    return Symtab<ELF32LE>::X->resolve(Name, Sym);
> +  case ELF32BEKind:
> +    return Symtab<ELF32BE>::X->resolve(Name, Sym);
> +  case ELF64LEKind:
> +    return Symtab<ELF64LE>::X->resolve(Name, Sym);
> +  case ELF64BEKind:
> +    return Symtab<ELF64BE>::X->resolve(Name, Sym);
> +  default:
> +    llvm_unreachable("unknown Config->EKind");
> +  }
> +}

Instead of this.

>  // If a symbol name contains '@', the characters after that is
>  // a symbol version name. This function parses that.
>  void SymbolBody::parseSymbolVersion() {
> @@ -241,9 +257,13 @@
>    // '@@' in a symbol name means the default version.
>    // It is usually the most recent one.
>    bool IsDefault = (Verstr[0] == '@');
> -  if (IsDefault)
> +  if (IsDefault) {
>      Verstr = Verstr.substr(1);
>  
> +    // name@@ver should also be used to resolve references to name.
> +    resolve(Name, this->symbol());
> +  }

Have parseSymbolVersion return true if the symbol is default. You can
then use that in the caller, which is templated.

Cheers,
Rafael