build: Fine-grained link-time dependency settings

Previously, all link-time dependencies were added for all libraries,
resulting in bogus link-time dependencies since not all dependencies
are shared across libraries. Also, in some cases like libavutil, not
all dependencies were taken into account, resulting in some cases of
underlinking.

To address all this mess a machinery is added for tracking which
dependency belongs to which library component and then leveraged
to determine correct dependencies for all individual libraries.

Makefile

@@ -97,7 +97,7 @@ FF_DEP_LIBS  := $(DEP_LIBS)
 FF_STATIC_DEP_LIBS := $(STATIC_DEP_LIBS)
 
 $(TOOLS): %$(EXESUF): %.o
-	$(LD) $(LDFLAGS) $(LDEXEFLAGS) $(LD_O) $^ $(EXTRALIBS) $(ELIBS)
+	$(LD) $(LDFLAGS) $(LDEXEFLAGS) $(LD_O) $^ $(EXTRALIBS-$(*F)) $(EXTRALIBS) $(ELIBS)
 
 CONFIGURABLE_COMPONENTS =                                           \
     $(wildcard $(FFLIBS:%=$(SRC_PATH)/lib%/all*.c))                 \

avbuild/common.mak

@@ -8,7 +8,7 @@ OBJS      += $(OBJS-yes)
 FFLIBS    := $($(NAME)_FFLIBS) $(FFLIBS-yes) $(FFLIBS)
 TESTPROGS += $(TESTPROGS-yes)
 
-FFEXTRALIBS := $(FFLIBS:%=$(LD_LIB)) $(EXTRALIBS)
+FFEXTRALIBS := $(FFLIBS:%=$(LD_LIB)) $(foreach lib,EXTRALIBS-$(NAME) $(FFLIBS:%=EXTRALIBS-%),$($(lib))) $(EXTRALIBS)
 
 OBJS      := $(sort $(OBJS:%=$(SUBDIR)%))
 TESTOBJS  := $(TESTOBJS:%=$(SUBDIR)tests/%) $(TESTPROGS:%=$(SUBDIR)tests/%.o)

avbuild/library.mak

@@ -30,7 +30,7 @@ $(TOOLS):     THISLIB = $(NAME:%=$(LD_LIB))
 $(TESTPROGS): THISLIB = $(SUBDIR)$(LIBNAME)
 
 $(TESTPROGS) $(TOOLS): %$(EXESUF): %.o
-	$$(LD) $(LDFLAGS) $(LDEXEFLAGS) $$(LD_O) $$(filter %.o,$$^) $$(THISLIB) $(FFEXTRALIBS) $$(ELIBS)
+	$$(LD) $(LDFLAGS) $(LDEXEFLAGS) $$(LD_O) $$(filter %.o,$$^) $$(THISLIB) $(FFEXTRALIBS) $$(EXTRALIBS-$$(*F)) $$(ELIBS)
 
 $(SUBDIR)lib$(NAME).version: $(SUBDIR)version.h | $(SUBDIR)
 	$$(M) $$(SRC_PATH)/avbuild/libversion.sh $(NAME) $$< > $$@

configure

@@ -610,7 +610,7 @@ is_in(){
     return 1
 }
 
-do_check_deps(){
+check_deps(){
     for cfg; do
         enabled ${cfg}_checking && die "Circular dependency for $cfg."
         disabled ${cfg}_checking && continue
@@ -626,7 +626,7 @@ do_check_deps(){
         eval dep_ifn="\$${cfg}_if_any"
 
         pushvar cfg dep_all dep_any dep_con dep_sel dep_sgs dep_ifa dep_ifn
-        do_check_deps $dep_all $dep_any $dep_con $dep_sel $dep_sgs $dep_ifa $dep_ifn
+        check_deps $dep_all $dep_any $dep_con $dep_sel $dep_sgs $dep_ifa $dep_ifn
         popvar cfg dep_all dep_any dep_con dep_sel dep_sgs dep_ifa dep_ifn
 
         [ -n "$dep_ifa" ] && { enabled_all $dep_ifa && enable_weak $cfg; }
@@ -639,24 +639,17 @@ do_check_deps(){
         if enabled $cfg; then
             enable_deep $dep_sel
             enable_deep_weak $dep_sgs
+            for dep in $dep_all $dep_any $dep_sgs; do
+                # filter out library deps, these do not belong in extralibs
+                is_in $dep $LIBRARY_LIST && continue
+                enabled $dep && eval append ${cfg}_extralibs ${dep}_extralibs
+            done
         fi
 
         disable ${cfg}_checking
     done
 }
 
-check_deps(){
-    unset allopts
-
-    do_check_deps "$@"
-
-    for cfg in $allopts; do
-        enabled $cfg || continue
-        eval dep_extralibs="\$${cfg}_extralibs"
-        test -n "$dep_extralibs" && add_extralibs $dep_extralibs
-    done
-}
-
 print_config(){
     pfx=$1
     files=$2
@@ -711,6 +704,15 @@ unique(){
     eval "$var=\"${uniq_list}\""
 }
 
+resolve(){
+    var=$1
+    tmpvar=
+    for entry in $(eval echo \$$var); do
+        tmpvar="$tmpvar $(eval echo \$${entry})"
+    done
+    eval "$var=\"${tmpvar}\""
+}
+
 add_cppflags(){
     append CPPFLAGS "$@"
 }
@@ -1015,7 +1017,7 @@ check_lib(){
     shift 3
     disable $name
     check_func_headers "$headers" "$funcs" "$@" &&
-        enable $name && add_extralibs "$@"
+        enable $name && eval ${name}_extralibs="\$@"
 }
 
 check_pkg_config(){
@@ -1033,7 +1035,7 @@ check_pkg_config(){
     check_func_headers "$headers" "$funcs" $pkg_cflags $pkg_libs "$@" &&
         enable $name &&
         add_cflags    "$pkg_cflags" &&
-        add_extralibs "$pkg_libs"
+        eval $(sanitize_var_name ${name}_extralibs)="\$pkg_libs"
 }
 
 check_exec(){
@@ -1252,6 +1254,12 @@ EXAMPLE_LIST="
     transcode_aac_example
 "
 
+# catchall list of things that require external libs to link
+EXTRALIBS_LIST="
+    cpu_init
+    cws2fws
+"
+
 HWACCEL_LIBRARY_NONFREE_LIST="
     cuda
     libnpp
@@ -2497,6 +2505,10 @@ output_example_deps="avcodec avformat avresample avutil swscale"
 qsvdec_example_deps="avcodec avutil libmfx h264_qsv_decoder"
 transcode_aac_example_deps="avcodec avformat avresample"
 
+# EXTRALIBS_LIST
+cpu_init_extralibs="pthreads_extralibs"
+cws2fws_extralibs="zlib_extralibs"
+
 # libraries, in linking order
 avcodec_deps="avutil"
 avcodec_select="null_bsf"
@@ -2507,15 +2519,25 @@ avformat_suggest="network"
 avresample_deps="avutil"
 swscale_deps="avutil"
 
+avcodec_extralibs="pthreads_extralibs libm_extralibs"
+avdevice_extralibs="libm_extralibs"
+avformat_extralibs="libm_extralibs"
+avfilter_extralibs="pthreads_extralibs libm_extralibs"
+avresample_extralibs="libm_extralibs"
+avutil_extralibs="clock_gettime_extralibs cuda_extralibs libm_extralibs libmfx_extralibs nanosleep_extralibs user32_extralibs vaapi_extralibs vaapi_drm_extralibs vaapi_x11_extralibs vdpau_x11_extralibs wincrypt_extralibs"
+swscale_extralibs="libm_extralibs"
+
 # programs
 avconv_deps="avcodec avfilter avformat avresample swscale"
 avconv_select="aformat_filter anull_filter asyncts_filter atrim_filter format_filter
                fps_filter null_filter resample_filter scale_filter
                trim_filter"
+avconv_suggest="dxva2_lib ole32 psapi shell32"
 avplay_deps="avcodec avfilter avformat avresample sdl"
-avplay_extralibs='$sdl_extralibs'
 avplay_select="rdft format_filter transpose_filter hflip_filter vflip_filter"
+avplay_suggest="shell32"
 avprobe_deps="avcodec avformat"
+avprobe_suggest="shell32"
 
 # documentation
 pod2man_deps="doc"
@@ -2573,6 +2595,9 @@ enable valgrind_backtrace
 # By default, enable only those hwaccels that have no external dependencies.
 enable d3d11va dxva2 vda vdpau
 
+# internal components are enabled by default
+enable $EXTRALIBS_LIST
+
 # Avoid external, non-system, libraries getting enabled by dependency resolution
 disable $EXTERNAL_LIBRARY_LIST
 
@@ -2669,20 +2694,36 @@ find_things_extern(){
 BSF_LIST=$(find_things_extern bsf AVBitStreamFilter libavcodec/bitstream_filters.c)
 PROTOCOL_LIST=$(find_things_extern protocol URLProtocol libavformat/protocols.c)
 
-ALL_COMPONENTS="
+AVCODEC_COMPONENTS_LIST="
     $BSF_LIST
     $DECODER_LIST
-    $DEMUXER_LIST
     $ENCODER_LIST
-    $FILTER_LIST
     $HWACCEL_LIST
+    $PARSER_LIST
+"
+
+AVDEVICE_COMPONENTS_LIST="
     $INDEV_LIST
-    $MUXER_LIST
     $OUTDEV_LIST
-    $PARSER_LIST
+"
+
+AVFILTER_COMPONENTS_LIST="
+    $FILTER_LIST
+"
+
+AVFORMAT_COMPONENTS_LIST="
+    $DEMUXER_LIST
+    $MUXER_LIST
     $PROTOCOL_LIST
 "
 
+ALL_COMPONENTS="
+    $AVCODEC_COMPONENTS_LIST
+    $AVDEVICE_COMPONENTS_LIST
+    $AVFILTER_COMPONENTS_LIST
+    $AVFORMAT_COMPONENTS_LIST
+"
+
 for n in $COMPONENT_LIST; do
     v=$(toupper ${n%s})_LIST
     eval enable \$$v
@@ -4525,7 +4566,7 @@ check_func  ${malloc_prefix}posix_memalign      && enable posix_memalign
 
 check_cpp_condition unistd.h "defined(_POSIX_MONOTONIC_CLOCK)" &&
     check_func_headers time.h clock_gettime ||
-        { check_lib clock_gettime time.h clock_gettime -lrt && LIBRT="-lrt"; }
+        check_lib clock_gettime time.h clock_gettime -lrt
 
 check_func  fcntl
 check_func  fork
@@ -4638,14 +4679,14 @@ disabled bzlib || check_lib bzlib bzlib.h BZ2_bzlibVersion -lbz2
 # On some systems dynamic loading requires no extra linker flags
 check_lib libdl dlfcn.h dlopen || check_lib libdl dlfcn.h dlopen -ldl
 
-check_lib libm math.h sin -lm && LIBM="-lm"
+check_lib libm math.h sin -lm
 
 atan2f_args=2
 ldexpf_args=2
 powf_args=2
 
 for func in $MATH_FUNCS; do
-    eval check_mathfunc $func \${${func}_args:-1} $LIBM
+    eval check_mathfunc $func \${${func}_args:-1} $libm_extralibs
 done
 
 # these are off by default, so fail if requested and not available
@@ -4716,10 +4757,10 @@ enabled mmal              && { check_lib mmal interface/mmal/mmal.h mmal_port_co
                                  check_lib mmal interface/mmal/mmal.h mmal_port_connect -lmmal_core -lmmal_util -lmmal_vc_client -lbcm_host; } ||
                                die "ERROR: mmal not found" &&
                                check_func_headers interface/mmal/mmal.h "MMAL_PARAMETER_VIDEO_MAX_NUM_CALLBACKS"; }
+enabled omx               && require_header OMX_Core.h
 enabled omx_rpi           && { check_header OMX_Core.h ||
                                { ! enabled cross_compile && add_cflags -isystem/opt/vc/include/IL && check_header OMX_Core.h ; } ||
-                               die "ERROR: OpenMAX IL headers not found"; }
-enabled omx               && require_header OMX_Core.h
+                               die "ERROR: OpenMAX IL headers not found"; } && enable omx
 enabled openssl           && { { check_pkg_config openssl openssl openssl/ssl.h OPENSSL_init_ssl ||
                                  check_pkg_config openssl openssl openssl/ssl.h SSL_library_init; } ||
                                check_lib openssl openssl/ssl.h SSL_library_init -lssl -lcrypto ||
@@ -5069,6 +5110,43 @@ check_deps $CONFIG_LIST       \
            $HAVE_LIST         \
            $ALL_COMPONENTS    \
 
+flatten_extralibs(){
+    unset nested_entries
+    list_name=$1
+    eval list=\$${1}
+    for entry in $list; do
+        entry_copy=$entry
+        resolve entry_copy
+        append nested_entries $(filter '*_extralibs' $entry_copy)
+        flat_entries=$(filter_out '*_extralibs' $entry_copy)
+        eval $entry="\$flat_entries"
+    done
+    append $list_name "$nested_entries"
+
+    resolve nested_entries
+    if test -n "$(filter '*_extralibs' $nested_entries)"; then
+        flatten_extralibs $list_name
+    fi
+}
+
+for linkunit in $LIBRARY_LIST; do
+    unset current_extralibs
+    eval components=\$$(toupper ${linkunit})_COMPONENTS_LIST
+    for comp in ${components}; do
+        enabled $comp || continue
+        comp_extralibs="${comp}_extralibs"
+        append current_extralibs $comp_extralibs
+    done
+    eval prepend ${linkunit}_extralibs $current_extralibs
+done
+
+for linkunit in $LIBRARY_LIST $PROGRAM_LIST $EXTRALIBS_LIST; do
+    flatten_extralibs ${linkunit}_extralibs
+    unique  ${linkunit}_extralibs
+    resolve ${linkunit}_extralibs
+    eval ${linkunit}_extralibs=\$\(\$ldflags_filter \$${linkunit}_extralibs\)
+done
+
 map 'enabled $v && intrinsics=${v#intrinsics_}' $INTRINSICS_LIST
 
 for thread in $THREADS_LIST; do
@@ -5313,7 +5391,6 @@ TARGET_PATH=$target_path
 TARGET_SAMPLES=${target_samples:-\$(SAMPLES)}
 CFLAGS-avplay=$sdl_cflags
 CFLAGS_HEADERS=$CFLAGS_HEADERS
-ZLIB=$($ldflags_filter -lz)
 LIB_INSTALL_EXTRA_CMD=$LIB_INSTALL_EXTRA_CMD
 EXTRALIBS=$extralibs
 COMPAT_OBJS=$compat_objs
@@ -5335,12 +5412,9 @@ EOF
 
 map 'eval echo "${v}_FFLIBS=\$${v}_deps" >> avbuild/config.mak' $LIBRARY_LIST
 
-print_program_extralibs(){
-    eval "program_extralibs=\$${1}_extralibs"
-    eval echo "EXTRALIBS-${1}=${program_extralibs}" >> avbuild/config.mak
-}
-
-map 'print_program_extralibs $v' $PROGRAM_LIST
+for entry in $LIBRARY_LIST $PROGRAM_LIST $EXTRALIBS_LIST; do
+    eval echo "EXTRALIBS-${entry}=\$${entry}_extralibs" >> avbuild/config.mak
+done
 
 cat > $TMPH <<EOF
 /* Automatically generated by configure - do not modify! */
@@ -5422,13 +5496,13 @@ incdir=$incdir
 source_path=${source_path}
 LIBPREF=${LIBPREF}
 LIBSUF=${LIBSUF}
-extralibs_avutil="$LIBRT $LIBM"
-extralibs_avcodec="$extralibs"
-extralibs_avformat="$extralibs"
-extralibs_avdevice="$extralibs"
-extralibs_avfilter="$extralibs"
-extralibs_avresample="$LIBM"
-extralibs_swscale="$LIBM"
+extralibs_avutil="$avutil_extralibs"
+extralibs_avcodec="$avcodec_extralibs"
+extralibs_avformat="$avformat_extralibs"
+extralibs_avdevice="$avdevice_extralibs"
+extralibs_avfilter="$avfilter_extralibs"
+extralibs_avresample="$avresample_extralibs"
+extralibs_swscale="$swscale_extralibs"
 EOF
 
 for lib in $LIBRARY_LIST; do

tests/checkasm/Makefile

@@ -35,7 +35,7 @@ OBJDIRS += $(CHECKASMDIRS)
 CHECKASM := tests/checkasm/checkasm$(EXESUF)
 
 $(CHECKASM): $(CHECKASMOBJS) $(FF_STATIC_DEP_LIBS)
-	$(LD) $(LDFLAGS) $(LDEXEFLAGS) $(LD_O) $(CHECKASMOBJS) $(FF_STATIC_DEP_LIBS) $(EXTRALIBS)
+	$(LD) $(LDFLAGS) $(LDEXEFLAGS) $(LD_O) $(CHECKASMOBJS) $(FF_STATIC_DEP_LIBS) $(EXTRALIBS-avcodec) $(EXTRALIBS-avutil) $(EXTRALIBS)
 
 checkasm: $(CHECKASM)