[Openmp-dev] [PATCH] [Revised] Initial cmake support

[Jack Howarth]

Below is what I had in mind for the installation commands of CMakelists.txt
once we have the cmake build
of openmp hooked up to the llvm bootstrap…

install(
  FILES omp.h
  PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
  DESTINATION lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include
)
install(
  FILES libiomp5.${OMP_SHLIBEXT}
  PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE
 WORLD_READ WORLD_EXECUTE
  DESTINATION lib${LLVM_LIBDIR_SUFFIX}
)

This mimics what we have been doing in fink. Placing the omp.h header in
 lib${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION}/include automatically
allows the compiler to find it. In fink, we have been installing
 libiomp5.${OMP_SHLIBEXT} in lib${LLVM_LIBDIR_SUFFIX} and using a patch…

--- cfe-3.4.1.src/lib/Driver/Tools.cpp.orig     2014-05-20
16:54:39.000000000 -0400
+++ cfe-3.4.1.src/lib/Driver/Tools.cpp  2014-05-20 17:01:28.000000000 -0400
@@ -5123,9 +5123,12 @@

   Args.AddAllArgs(CmdArgs, options::OPT_L);

-  if (Args.hasArg(options::OPT_fopenmp))
+  if (Args.hasArg(options::OPT_fopenmp)) {
+    // Help clang find libiomp5.dylib
+    CmdArgs.push_back("-L at FINK_PREFIX@/opt/llvm-3.4/lib");
     // This is more complicated in gcc...
     CmdArgs.push_back("-liomp5");
+  }

   AddLinkerInputs(getToolChain(), Inputs, Args, CmdArgs);

@@ -6690,7 +6693,9 @@

       bool OpenMP = Args.hasArg(options::OPT_fopenmp);
       if (OpenMP) {
-        CmdArgs.push_back("-liomp5");
+       // Help clang find libiomp5.dylib
+       CmdArgs.push_back("-L at FINK_PREFIX@/opt/llvm-3.4/lib");
+       CmdArgs.push_back("-liomp5");
       }

       AddLibgcc(ToolChain.getTriple(), D, CmdArgs, Args);

to help clang find it there. So we would change @FINK_PREFIX@ to the
complete path to the installed lib${LLVM_LIBDIR_SUFFIX}. The alternative
would be to change the patch above to replace -liomp5 with a the full
path to the installed  lib${LLVM_LIBDIR_SUFFIX}/libomp5.${OMP_SHLIBEXT}
instead.

 This brings up several questions…

1) Where do you intend to place libomp5.${OMP_SHLIBEXT}?

2) If it is installed outside of  lib${LLVM_LIBDIR_SUFFIX}, how do
 you plan on handling having multiple versions of llvm/clang installed
 on the same machine which will all claim to ownership of
libomp5.${OMP_SHLIBEXT}?

 My proposal for solving the issue of co-existing libomp5.${OMP_SHLIBEXT}
would be…

 Create  libomp5.${VERSION}.${SOVERSION}.${OMP_SHLIBEXT}, where SOVERSION
 is set to the release number of the llvm/clang/openmp release and create a
symlink
 for  libomp5.${OMP_SHLIBEXT} pointing at
libomp5.${VERSION}.${SOVERSION}.${OMP_SHLIBEXT}.
 Install these two files in  lib${LLVM_LIBDIR_SUFFIX} and use additional
symlinks to them
 in an exposed directory like /usr/lib. These two symlinks in the exposed
directory would be
 swapped out when a particular releases of llvm/clang/openmp was designated
as the system
 one (i.e. they would end up in a conflicting  clang34-dev or clang35-dev
packaging).

 I think this would allow binaries to be compiled against a specific
release of openmp and
 insure that the resulting executables would find the original copy of
libiomp5 for that
 release of llvm/clang/openmp as installed in  lib${LLVM_LIBDIR_SUFFIX} as
 libomp5.${VERSION}.${SOVERSION}.${OMP_SHLIBEXT}..

 Sorry if that wasn't as clear as I intended but hopefully you will all get
the idea.



On Sat, May 31, 2014 at 9:41 PM, Jack Howarth <
howarth.mailing.lists at gmail.com> wrote:

>    Attached is the revised initial implementation of cmake support for
> openmp in llvm.org with the following requested changes implemented.
>
> 1) Indentations normalized to 2 spaces.
> 2) The test for APPLE moved above UNIX in setting OS_GEN and fatal error
> condition added.
> 3) Implemented used CMAKE_SHARED_LIBRARY_SUFFIX to set OMP_SHLIBEXT.
> 4) Added comment explaining the rational for temporary forcing of…
>
> set(CMAKE_CXX_COMPILER "clang++")
>
> to insure that the build of 'make compiler=clang' is always used,
> regardless of the actual system compiler, until the openmp build is wired
> into the llvm bootstrap and can be certain to use its clang compilers. Also
> note that the warnings added to the COMMON_FLAGS may be compiler-specific.
> Tested as before on x86_64-apple-darwin12 against the clang compilers from
> Xcode 5.1.1 and on x86_64 Fedora 15 using current clang-omp 3.4.
>                   Jack
> ps We also probably want to add a fatal error message for unsupported
> arches but first I intend to adjust this file to support powerpc as soon as
> my clang-omp bootstrap completes on ppc darwin9.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/openmp-dev/attachments/20140531/865e19e1/attachment.html>