[Mesa-dev] [PATCH] configure.ac: Respect LLVM_CFLAGS in LLVM version detection

[Tobias Droste]

Hi Tomasz,

does this actually fix anything?

Because right now llvm-config.h does not include anything and I doubt it will 
in the future, as it's just a collection of defines.
The path to the header file itself is given by llvm-config ($LLVM_INCLUDEDIR).

Did you just happen to see this or do you get an error without this patch?

Tobias

Am Mittwoch, 14. Dezember 2016, 17:00:27 CET schrieb Tomasz Figa:
> When compiling LLVM headers, including llvm-config.h, we need to respect
> LLVM_CFLAGS. This is especially crucial if LLVM is located in a
> non-standard location and it happens that llvm-config.h includes another
> header. In such case the detection would fail due to missing header,
> because the path is provided in LLVM_CFLAGS.
> 
> Let's add LLVM_CFLAGS to global CFLAGS for the time of detection and then
> restore the original flags, as done in other places of the script.
> 
> Signed-off-by: Tomasz Figa <tfiga at chromium.org>
> ---
>  configure.ac | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/configure.ac b/configure.ac
> index 799f5eb..8fd7120 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -978,6 +978,10 @@ llvm_set_environment_variables() {
>          LLVM_INCLUDEDIR=`$LLVM_CONFIG --includedir`
>          LLVM_LIBDIR=`$LLVM_CONFIG --libdir`
> 
> +        # We need to respect LLVM_CFLAGS when compiling LLVM headers.
> +        save_CFLAGS="$CFLAGS"
> +        CFLAGS="$CFLAGS $LLVM_CFLAGS"
> +
>          AC_COMPUTE_INT([LLVM_VERSION_MAJOR], [LLVM_VERSION_MAJOR],
>              [#include "${LLVM_INCLUDEDIR}/llvm/Config/llvm-config.h"])
>          AC_COMPUTE_INT([LLVM_VERSION_MINOR], [LLVM_VERSION_MINOR],
> @@ -985,6 +989,8 @@ llvm_set_environment_variables() {
>          AC_COMPUTE_INT([LLVM_VERSION_PATCH], [LLVM_VERSION_PATCH],
>              [#include "${LLVM_INCLUDEDIR}/llvm/Config/llvm-config.h"])
> 
> +        CFLAGS="$save_CFLAGS"
> +
>          # Only needed for LLVM < 3.6.0
>          if test -z "$LLVM_VERSION_PATCH"; then
>              LLVM_VERSION_PATCH=0