[lld] r300007 - [lld] Keep full library path in DT_NEEDED.

[Rafael Espíndola via llvm-commits]

On 11 April 2017 at 19:46, Evgeniy Stepanov via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Author: eugenis
> Date: Tue Apr 11 18:46:58 2017
> New Revision: 300007
>
> URL: http://llvm.org/viewvc/llvm-project?rev=300007&view=rev
> Log:
> [lld] Keep full library path in DT_NEEDED.
>
> Fixes PR32572.
>
> When
>     (a) a library has no soname
> and (b) library is given on the command line with path (and not through -L/-l flags)
> DT_NEEDED entry for such library keeps the path as given.
>
> This behavior is consistent with gold and bfd, and is used in compiler-rt test suite.
>
> Added:
>     lld/trunk/test/ELF/no-soname.s
> Modified:
>     lld/trunk/ELF/Driver.cpp
>     lld/trunk/ELF/Driver.h
>     lld/trunk/ELF/InputFiles.cpp
>     lld/trunk/ELF/InputFiles.h
>     lld/trunk/ELF/ScriptParser.cpp
>     lld/trunk/test/ELF/as-needed-no-reloc.s
>     lld/trunk/test/ELF/relro-omagic.s
>
> Modified: lld/trunk/ELF/Driver.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Driver.cpp?rev=300007&r1=300006&r2=300007&view=diff
> ==============================================================================
> --- lld/trunk/ELF/Driver.cpp (original)
> +++ lld/trunk/ELF/Driver.cpp Tue Apr 11 18:46:58 2017
> @@ -153,7 +153,7 @@ LinkerDriver::getArchiveMembers(MemoryBu
>
>  // Opens and parses a file. Path has to be resolved already.
>  // Newly created memory buffers are owned by this driver.
> -void LinkerDriver::addFile(StringRef Path) {
> +void LinkerDriver::addFile(StringRef Path, bool WithLOption) {
>    using namespace sys::fs;
>
>    Optional<MemoryBufferRef> Buffer = readFile(Path);
> @@ -184,6 +184,11 @@ void LinkerDriver::addFile(StringRef Pat
>        return;
>      }
>      Files.push_back(createSharedFile(MBRef));
> +    // If the library is found at an explicitly given path use the entire path
> +    // as he default soname. Such libraries should not require RPATH or
> +    // LD_LIBRARY_PATH to run.
> +    Files.back()->DefaultSoName =
> +        WithLOption ? sys::path::filename(Path) : Path;
>      return;
>    default:
>      if (InLib)
> @@ -196,7 +201,7 @@ void LinkerDriver::addFile(StringRef Pat
>  // Add a given library by searching it from input search paths.
>  void LinkerDriver::addLibrary(StringRef Name) {
>    if (Optional<std::string> Path = searchLibrary(Name))
> -    addFile(*Path);
> +    addFile(*Path, /*WithLOption=*/true);
>    else
>      error("unable to find library -l" + Name);
>  }
> @@ -762,7 +767,7 @@ void LinkerDriver::createFiles(opt::Inpu
>        addLibrary(Arg->getValue());
>        break;
>      case OPT_INPUT:
> -      addFile(Arg->getValue());
> +      addFile(Arg->getValue(), /*WithLOption=*/false);
>        break;
>      case OPT_alias_script_T:
>      case OPT_script:
>
> Modified: lld/trunk/ELF/Driver.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Driver.h?rev=300007&r1=300006&r2=300007&view=diff
> ==============================================================================
> --- lld/trunk/ELF/Driver.h (original)
> +++ lld/trunk/ELF/Driver.h Tue Apr 11 18:46:58 2017
> @@ -27,7 +27,7 @@ extern class LinkerDriver *Driver;
>  class LinkerDriver {
>  public:
>    void main(ArrayRef<const char *> Args, bool CanExitEarly);
> -  void addFile(StringRef Path);
> +  void addFile(StringRef Path, bool WithLOption);
>    void addLibrary(StringRef Name);
>
>  private:
>
> Modified: lld/trunk/ELF/InputFiles.cpp
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputFiles.cpp?rev=300007&r1=300006&r2=300007&view=diff
> ==============================================================================
> --- lld/trunk/ELF/InputFiles.cpp (original)
> +++ lld/trunk/ELF/InputFiles.cpp Tue Apr 11 18:46:58 2017
> @@ -661,7 +661,7 @@ template <class ELFT> void SharedFile<EL
>    // DSOs are identified by soname, and they usually contain
>    // DT_SONAME tag in their header. But if they are missing,
>    // filenames are used as default sonames.
> -  SoName = sys::path::filename(this->getName());
> +  SoName = this->DefaultSoName;
>
>    if (!DynamicSec)
>      return;
>
> Modified: lld/trunk/ELF/InputFiles.h
> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputFiles.h?rev=300007&r1=300006&r2=300007&view=diff
> ==============================================================================
> --- lld/trunk/ELF/InputFiles.h (original)
> +++ lld/trunk/ELF/InputFiles.h Tue Apr 11 18:46:58 2017
> @@ -93,6 +93,10 @@ public:
>    uint16_t EMachine = llvm::ELF::EM_NONE;
>    uint8_t OSABI = 0;
>
> +  // For SharedKind inputs, the string to use in DT_NEEDED when the library
> +  // has no soname.
> +  std::string DefaultSoName;

Why do you need this to be in the base class?

Cheers,
Rafael