[Mesa-dev] [PATCH 2/7] configure.ac: factor out detection for old and buggy llvm

[Tobias Droste]

Reviewed-by: Tobias Droste <tdroste at gmx.de>

Am Donnerstag, 5. Oktober 2017, 12:19:04 CEST schrieb Emil Velikov:
> From: Emil Velikov <emil.velikov at collabora.com>
> 
> As of LLVM 3.9 one could use consistent ways to handle the component.
> Factor out the current handling, as it will be used for older versions.
> 
> Cc: mesa-stable at lists.freedesktop.org
> Cc: Michel Dänzer <michel.daenzer at amd.com>
> Signed-off-by: Emil Velikov <emil.velikov at collabora.com>
> ---
> I'm not overly excited about getting this in stable, but without it the
> follow-up fix will be quite invasive.
> 
>  - Alternative name suggestions?
>  - Should we lift even more into the helper?
> ---
>  configure.ac | 63
> ++++++++++++++++++++++++++++++++---------------------------- 1 file
> changed, 34 insertions(+), 29 deletions(-)
> 
> diff --git a/configure.ac b/configure.ac
> index dd095fafaad..308938a5a88 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -2634,6 +2634,39 @@ if test "x$HAVE_GALLIUM_VC4" != xyes -a
> "x$HAVE_GALLIUM_PL111" = xyes  ; then AC_MSG_ERROR([Building with pl111
> requires vc4])
>  fi
> 
> +
> +detect_old_buggy_llvm() {
> +    dnl llvm-config may not give the right answer when llvm is a built as a
> +    dnl single shared library, so we must work the library name out for + 
>   dnl ourselves.
> +    dnl (See https://llvm.org/bugs/show_bug.cgi?id=6823)
> +    dnl We can't use $LLVM_VERSION because it has 'svn' stripped out,
> +    LLVM_SO_NAME=LLVM-`$LLVM_CONFIG --version`
> +    AS_IF([test -f "$LLVM_LIBDIR/lib$LLVM_SO_NAME.$IMP_LIB_EXT"],
> [llvm_have_one_so=yes]) +
> +    if test "x$llvm_have_one_so" = xyes; then
> +        dnl LLVM was built using auto*, so there is only one shared object.
> +        LLVM_LIBS="-l$LLVM_SO_NAME"
> +    else
> +        dnl If LLVM was built with CMake, there will be one shared object
> per +        dnl component.
> +        AS_IF([test ! -f "$LLVM_LIBDIR/libLLVMTarget.$IMP_LIB_EXT"],
> +               [AC_MSG_ERROR([Could not find llvm shared libraries:
> +                Please make sure you have built llvm with the
> --enable-shared option +                and that your llvm libraries are
> installed in $LLVM_LIBDIR +                If you have installed your llvm
> libraries to a different directory you +                can use the
> --with-llvm-prefix= configure flag to specify this directory. +            
>    NOTE: Mesa is attempting to use llvm shared libraries by default. +     
>           If you do not want to build with llvm shared libraries and
> instead want to +                use llvm static libraries then add
> --disable-llvm-shared-libs to your configure +                invocation
> and rebuild.])])
> +
> +        dnl We don't need to update LLVM_LIBS in this case because the LLVM
> +        dnl install uses a shared object for each component and we have + 
>       dnl already added all of these objects to LLVM_LIBS.
> +    fi
> +}
> +
>  dnl
>  dnl Set defines and buildtime variables only when using LLVM.
>  dnl
> @@ -2655,35 +2688,7 @@ if test "x$enable_llvm" = xyes; then
> 
>      if test "x$enable_llvm_shared_libs" = xyes; then
>          if test $LLVM_VERSION_MAJOR -lt 4 -o "`$LLVM_CONFIG --shared-mode
> ${LLVM_COMPONENTS}`" = static; then -            dnl llvm-config may not
> give the right answer when llvm is a built as a -            dnl single
> shared library, so we must work the library name out for -            dnl
> ourselves.
> -            dnl (See https://llvm.org/bugs/show_bug.cgi?id=6823)
> -            dnl We can't use $LLVM_VERSION because it has 'svn' stripped
> out, -            LLVM_SO_NAME=LLVM-`$LLVM_CONFIG --version`
> -            AS_IF([test -f "$LLVM_LIBDIR/lib$LLVM_SO_NAME.$IMP_LIB_EXT"],
> [llvm_have_one_so=yes]) -
> -            if test "x$llvm_have_one_so" = xyes; then
> -               dnl LLVM was built using auto*, so there is only one shared
> object. -               LLVM_LIBS="-l$LLVM_SO_NAME"
> -            else
> -                dnl If LLVM was built with CMake, there will be one shared
> object per -                dnl component.
> -                AS_IF([test ! -f
> "$LLVM_LIBDIR/libLLVMTarget.$IMP_LIB_EXT"], -                     
> [AC_MSG_ERROR([Could not find llvm shared libraries: -                     
>  Please make sure you have built llvm with the --enable-shared option -    
>                   and that your llvm libraries are installed in
> $LLVM_LIBDIR -                       If you have installed your llvm
> libraries to a different directory you -                       can use the
> --with-llvm-prefix= configure flag to specify this directory. -            
>           NOTE: Mesa is attempting to use llvm shared libraries by default.
> -                       If you do not want to build with llvm shared
> libraries and instead want to -                       use llvm static
> libraries then add --disable-llvm-shared-libs to your configure -          
>             invocation and rebuild.])])
> -
> -                dnl We don't need to update LLVM_LIBS in this case because
> the LLVM -                dnl install uses a shared object for each
> component and we have -                dnl already added all of these
> objects to LLVM_LIBS. -            fi
> +            detect_old_buggy_llvm
>          fi
>      else
>          AC_MSG_WARN([Building mesa with statically linked LLVM may cause
> compilation issues])