[FFmpeg-devel] [PATCH] configure: check if dlfcn.h is present for ladspa and frei0r, if not abort early

[Paul B Mahol]

On 12/2/18, James Almer <jamrial at gmail.com> wrote:
> On 12/2/2018 2:51 PM, Paul B Mahol wrote:
>> Fixes #4517.
>>
>> Signed-off-by: Paul B Mahol <onemda at gmail.com>
>> ---
>>  configure | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/configure b/configure
>> index 2af6c0d797..7c55274efa 100755
>> --- a/configure
>> +++ b/configure
>> @@ -6065,11 +6065,11 @@ enabled chromaprint       && require chromaprint
>> chromaprint.h chromaprint_get_v
>>  enabled decklink          && { require_headers DeckLinkAPI.h &&
>>                                 { test_cpp_condition DeckLinkAPIVersion.h
>> "BLACKMAGIC_DECKLINK_API_VERSION >= 0x0a090500" || die "ERROR: Decklink
>> API version must be >= 10.9.5."; } }
>>  enabled libndi_newtek     && require_headers Processing.NDI.Lib.h
>> -enabled frei0r            && require_headers frei0r.h
>> +enabled frei0r            && require_headers frei0r.h && require_headers
>> dlfcn.h
>>  enabled gmp               && require gmp gmp.h mpz_export -lgmp
>>  enabled gnutls            && require_pkg_config gnutls gnutls
>> gnutls/gnutls.h gnutls_global_init
>>  enabled jni               && { [ $target_os = "android" ] &&
>> check_headers jni.h && enabled pthreads || die "ERROR: jni not found"; }
>> -enabled ladspa            && require_headers ladspa.h
>> +enabled ladspa            && require_headers ladspa.h && require_headers
>> dlfcn.h
>>  enabled libaom            && require_pkg_config libaom "aom >= 1.0.0"
>> aom/aom_codec.h aom_codec_version
>>  enabled lv2               && require_pkg_config lv2 lilv-0 "lilv/lilv.h"
>> lilv_world_new
>>  enabled libiec61883       && require libiec61883 libiec61883/iec61883.h
>> iec61883_cmp_connect -lraw1394 -lavc1394 -lrom1394 -liec61883
>>
>
> Both filters already depend on libdl being present, which also implies
> dlfcn.h (The check for libdl uses it). How is that not enough?

Filters != library support enabled

Please read bug report I linked, it explains it.

In short not having dflcn.h header would pass those options but would
disable filters later.
Proper way is to abort early.