[PATCH] D47817: [sanitizer_common] Fix using libtirpc on Linux

[Peter Wu via Phabricator via cfe-commits]

Lekensteyn added a comment.

In https://reviews.llvm.org/D47817#1155717, @mgorny wrote:

> > This would be the first user of pkg-config here. I am not sure if this would be the best fix. Usually you cannot (easily) recompile libc and override it, but for external libs such as libtirpc this should be more doable (I think).
>
> I don't think libtirpc's include path is expected to be predictable by design. I think it's something distro maintainers have to choose to avoid collision with headers that (used to be) installed by glibc. In any case, I can't think of a better solution than pkg-config here (libtirpc doesn't come with CMake modules).


On Arch (libtirpc-1.0.3-2), Debian (libtirpc-dev 0.2.5-1.2 in sid), Gentoo (libtirpc-1.0.3), the include files happen to be installed in /usr/include/libtirpc, so it seems pretty consistent. So you could consider writing a `cmake/Modules/FindLibtirpc.cmake` module that looks like:

  # sets Libtirpc_FOUND Libtirpc_INCLUDE_DIRS
  
  find_path(Libtirpc_INCLUDE_DIR
    NAMES rpc/xdr.h
    PATH_SUFFIXES tirpc
  )
  include(FindPackageHandleStandardArgs)
  find_package_handle_standard_args(Libtirpc REQUIRED_VARS Libtirpc_INCLUDE_DIR)
  if(Libtirpc_FOUND)
    set(Libtirpc_INCLUDE_DIRS ${Libtirpc_INCLUDE_DIR})
  endif()

then you can use `find_package(Libtirpc)` without depending on `pkg-config`.

> libtirpc case never could have worked.

The reason for that is probably because of lib/sanitizer_common/sanitizer_platform.h saying:

  // Assume obsolete RPC headers are available by default
  #if !defined(HAVE_RPC_XDR_H) && !defined(HAVE_TIRPC_RPC_XDR_H)
  # define HAVE_RPC_XDR_H (SANITIZER_LINUX && !SANITIZER_ANDROID)
  # define HAVE_TIRPC_RPC_XDR_H 0
  #endif

That should probably be addressed too.


Repository:
  rCRT Compiler Runtime

https://reviews.llvm.org/D47817