[PATCH] Fix detection of compilation and linking flags for source-highlight

[Ruslan Kabatsayev]

Ping!

On Fri, 11 Feb 2022 at 20:10, <b7.10110111@gmail.com> wrote:
>
> From: Ruslan Kabatsayev <b7.10110111@gmail.com>
>
> Currently there are two problems with the detection via pkg-config:
> 1. LDFLAGS variable is used to pass --libs to AC_LINK_IFELSE, which
> results in the "-L/some/path -lsource-highlight" preceding the
> conftest.cpp, which results in failure to find symbol referenced in
> conftest.cpp.
> 2. CFLAGS variable is used to compile C++ code instead of CXXFLAGS. This
> results in --cflags not being passed to the compiler at all.
>
> This patch fixes both of these mistakes, letting me get a working GDB
> with source-highlight installed into a custom prefix ~/opt/gdb-git
> (because system repos provide too old version).
> ---
>  gdb/configure.ac | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/gdb/configure.ac b/gdb/configure.ac
> index 5a380ce38d9..c6fa19b20bc 100644
> --- a/gdb/configure.ac
> +++ b/gdb/configure.ac
> @@ -1242,10 +1242,10 @@ either use --disable-source-highlight or dnl
>        # This situation can occur for instance when using a source highlight
>        # library compiled with g++ 7.5.0 while building gdb with g++ 4.8.5.
>        AC_LANG_PUSH(C++)
> -      save_CFLAGS="$CFLAGS"
> -      save_LDFLAGS="$LDFLAGS"
> -      CFLAGS="$CFLAGS $srchigh_pkg_cflags"
> -      LDFLAGS="$LDFLAGS $srchigh_pkg_libs"
> +      save_CXXFLAGS="$CXXFLAGS"
> +      save_LIBS="$LIBS"
> +      CXXFLAGS="$CXXFLAGS $srchigh_pkg_cflags"
> +      LIBS="$LIBS $srchigh_pkg_libs"
>        AC_LINK_IFELSE(
>          [AC_LANG_PROGRAM(
>            [#include <srchilite/sourcehighlight.h>],
> @@ -1255,8 +1255,8 @@ either use --disable-source-highlight or dnl
>          [have_usable_source_highlight=yes],
>          [have_usable_source_highlight=no]
>        )
> -      CFLAGS="$save_CFLAGS"
> -      LDFLAGS="$save_LDFLAGS"
> +      CXXFLAGS="$save_CXXFLAGS"
> +      LIBS="$save_LIBS"
>        AC_LANG_POP(C++)
>
>        if test "${have_usable_source_highlight}" = "yes"; then
> --
> 2.16.2
>