[FFmpeg-devel] [PATCH] configure: add libm ldflags globally

[James Almer]

It's used by every library, and by making it global we simplify a lot
of checks.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 configure | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/configure b/configure
index 22026ef832..a0bfb269e8 100755
--- a/configure
+++ b/configure
@@ -3332,23 +3332,17 @@ cws2fws_extralibs="zlib_extralibs"
 
 # libraries, in linking order
 avcodec_deps="avutil"
-avcodec_suggest="libm"
 avcodec_select="null_bsf"
 avdevice_deps="avformat avcodec avutil"
-avdevice_suggest="libm"
 avfilter_deps="avutil"
-avfilter_suggest="libm"
 avformat_deps="avcodec avutil"
-avformat_suggest="libm network"
+avformat_suggest="network"
 avresample_deps="avutil"
-avresample_suggest="libm"
-avutil_suggest="clock_gettime libm libdrm libmfx opencl user32 vaapi videotoolbox corefoundation corevideo coremedia wincrypt"
+avutil_suggest="clock_gettime libdrm libmfx opencl user32 vaapi videotoolbox corefoundation corevideo coremedia wincrypt"
 postproc_deps="avutil gpl"
-postproc_suggest="libm"
 swresample_deps="avutil"
-swresample_suggest="libm libsoxr"
+swresample_suggest="libsoxr"
 swscale_deps="avutil"
-swscale_suggest="libm"
 
 avcodec_extralibs="pthreads_extralibs iconv_extralibs"
 avfilter_extralibs="pthreads_extralibs"
@@ -5944,7 +5938,9 @@ enabled  lzma && check_lib lzma   lzma.h lzma_version_number -llzma
 # On some systems dynamic loading requires no extra linker flags
 check_lib libdl dlfcn.h "dlopen dlsym" || check_lib libdl dlfcn.h "dlopen dlsym" -ldl
 
-check_lib libm math.h sin -lm
+# Add -lm to global extralibs if required. Every library uses it, and it simplifies
+# several of the external library checks below.
+check_lib libm math.h sin -lm && add_extralibs $libm_extralibs
 
 atan2f_args=2
 copysign_args=2
@@ -6098,7 +6094,7 @@ enabled libx264           && { use_pkg_config libx264 x264 "stdint.h x264.h" x26
                                enable libx262; }
 enabled libx265           && require_pkg_config libx265 x265 x265.h x265_api_get &&
                              require_cpp_condition x265.h "X265_BUILD >= 68"
-enabled libxavs           && require libxavs "stdint.h xavs.h" xavs_encoder_encode "-lxavs $pthreads_extralibs $libm_extralibs"
+enabled libxavs           && require libxavs "stdint.h xavs.h" xavs_encoder_encode "-lxavs $pthreads_extralibs"
 enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
 enabled libzimg           && require_pkg_config libzimg "zimg >= 2.3.0" zimg.h zimg_get_api_version
 enabled libzmq            && require_pkg_config libzmq libzmq zmq.h zmq_ctx_new
-- 
2.14.2