configure: Set PKG_CONFIG_PATH to get the right settings for the target host.

[Francois Gouget]

In an ideal world I think the previous patch would have been ok but due 
to the issues mentioned in the first paragraph this one may be better.

Regarding the 64 bit case, since we feel it necessary to set CC="$CC 
-m64", I think we should also set PKG_CONFIG_PATH to make sure the 64 
bit .pc files will be used rather than the 32 bit ones. What's a bit 
strange is that this branch does not have the "$cross_compiling" != 
"yes" check. This case being much less common I would be ok with 
dropping that part.



Ideally we would use the right <triplet>-pkg-config tool for the target
host. However Red Hat and SUSE respectively add '-redhat' and '-suse' to
the triplet which makes it hard to find the right tool. Furthermore on
Debian and derivatives a lot of development packages do not support
multiarch so that the required .pc files would not be found.

Setting PKG_CONFIG_PATH side-steps the non-standard Red Hat and SUSE
triplets. It also lets pkg-config fall back to the 'wrong' .pc files
on Debian which is fine in most cases, which using the right one in
cases where it matters (GStreamer 1.0), assuming they are actually
present.

Signed-off-by: Francois Gouget <fgouget at codeweavers.com>
---
 configure.ac | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/configure.ac b/configure.ac
index 71bf7ca2bf7..7ecf41846c5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -151,6 +151,8 @@ case $host in
       host_cpu="i386"
       notice_platform="32-bit "
       AC_SUBST(TARGETFLAGS,"-m32")
+      PKG_CONFIG_PATH="/usr/lib/i386-linux-gnu/pkgconfig:/usr/lib/pkgconfig"
+      export PKG_CONFIG_PATH
       enable_win16=${enable_win16:-yes}
     else
       if test "x${GCC}" = "xyes"
@@ -166,6 +168,8 @@ case $host in
       host_cpu="x86_64"
       notice_platform="64-bit "
       AC_SUBST(TARGETFLAGS,"-m64")
+      PKG_CONFIG_PATH="/usr/lib/x86_64-linux-gnu/pkgconfig:/usr/lib64/pkgconfig"
+      export PKG_CONFIG_PATH
     fi
     ;;
   arm*)
-- 
2.11.0