[PATCH 1/1] Fix gcov on Mac

[Alexander Turenko]

I think we should check for __gcov_flush on Mac OS too, because it is in
the libraries; for me in:

/Applications/Xcode83.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/8.1.0/lib/darwin/libclang_rt.profile_tvos.a
/Applications/Xcode83.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/8.1.0/lib/darwin/libclang_rt.profile_tvossim.a

Don't sure which one is actually used.

But we should not add -lgcov (it assumed by -ftest-coverage on GCC, but
not on clang).

This patch works for me on Mac OS (and should on Linux too):

diff --git a/cmake/profile.cmake b/cmake/profile.cmake
index 02d622187..3e8f1499b 100644
--- a/cmake/profile.cmake
+++ b/cmake/profile.cmake
@@ -1,4 +1,6 @@
-check_library_exists (gcov __gcov_flush  ""  HAVE_GCOV)
+set(CMAKE_REQUIRED_FLAGS "-fprofile-arcs -ftest-coverage")
+check_library_exists("" __gcov_flush "" HAVE_GCOV)
+set(CMAKE_REQUIRED_FLAGS "")
 
 set(ENABLE_GCOV_DEFAULT OFF)
 option(ENABLE_GCOV "Enable integration with gcov, a code coverage program" ${ENABLE_GCOV_DEFAULT})

WBR, Alexander Turenko.

On Tue, Dec 18, 2018 at 01:11:08PM +0300, Vladimir Davydov wrote:
> Alexander, please take a look.
> 
> On Mon, Dec 17, 2018 at 02:58:21PM +0300, Vladislav Shpilevoy wrote:
> > ---
> > https://github.com/tarantool/tarantool/tree/gerold103/enable-gcov-on-mac
> > 
> >  cmake/profile.cmake | 12 +++++++-----
> >  1 file changed, 7 insertions(+), 5 deletions(-)
> > 
> > diff --git a/cmake/profile.cmake b/cmake/profile.cmake
> > index 278399155..866c8a787 100644
> > --- a/cmake/profile.cmake
> > +++ b/cmake/profile.cmake
> > @@ -1,12 +1,16 @@
> > -check_library_exists (gcov __gcov_flush  ""  HAVE_GCOV)
> > +check_library_exists(gcov __gcov_flush  ""  HAVE_GCOV)
> >  
> >  set(ENABLE_GCOV_DEFAULT OFF)
> >  option(ENABLE_GCOV "Enable integration with gcov, a code coverage program" ${ENABLE_GCOV_DEFAULT})
> >  
> >  if (ENABLE_GCOV)
> >      if (NOT HAVE_GCOV)
> > -    message (FATAL_ERROR
> > -         "ENABLE_GCOV option requested but gcov library is not found")
> > +        if (CMAKE_COMPILER_IS_CLANG)
> > +            message(WARNING "GCOV is available on clang from 3.0.0")
> > +            set(HAVE_GCOV 1)
> > +        else()
> > +            message(FATAL_ERROR "ENABLE_GCOV option requested but gcov library is not found")
> > +        endif()
> >      endif()
> >  
> >      add_compile_flags("C;CXX"
> > @@ -18,8 +22,6 @@ if (ENABLE_GCOV)
> >      set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -ftest-coverage")
> >      set (CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -fprofile-arcs")
> >      set (CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -ftest-coverage")
> > -
> > -   # add_library(gcov SHARED IMPORTED)
> >  endif()
> >  
> >  if (NOT CMAKE_BUILD_TYPE STREQUAL "Debug")