doc: make doxygen program configurable

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

configure

@@ -286,6 +286,7 @@ Toolchain options:
   --pkg-config=PKGCONFIG   use pkg-config tool PKGCONFIG [$pkg_config_default]
   --pkg-config-flags=FLAGS pass additional flags to pkgconf []
   --ranlib=RANLIB          use ranlib RANLIB [$ranlib_default]
+  --doxygen=DOXYGEN        use DOXYGEN to generate API doc [$doxygen_default]
   --host-cc=HOSTCC         use host C compiler HOSTCC
   --host-cflags=HCFLAGS    use HCFLAGS when compiling for host
   --host-cppflags=HCPPFLAGS use HCPPFLAGS when compiling for host
@@ -1877,6 +1878,7 @@ CMDLINE_SET="
     cross_prefix
     cxx
     dep_cc
+    doxygen
     extra_version
     gas
     host_cc
@@ -2618,6 +2620,7 @@ cc_default="gcc"
 cxx_default="g++"
 host_cc_default="gcc"
 cp_f="cp -f"
+doxygen_default="doxygen"
 install="install"
 ln_s="ln -s -f"
 nm_default="nm -g"
@@ -2994,7 +2997,8 @@ case "$toolchain" in
     ;;
 esac
 
-set_default arch cc cxx pkg_config ranlib strip sysinclude target_exec target_os yasmexe
+set_default arch cc cxx doxygen pkg_config ranlib strip sysinclude \
+    target_exec target_os yasmexe
 enabled cross_compile || host_cc_default=$cc
 set_default host_cc
 
@@ -3003,6 +3007,11 @@ if ! $pkg_config --version >/dev/null 2>&1; then
     pkg_config=false
 fi
 
+if test $doxygen != $doxygen_default && \
+  ! $doxygen --version >/dev/null 2>&1; then
+    warn "Specified doxygen \"$doxygen\" not found, API documentation will fail to build."
+fi
+
 exesuf() {
     case $1 in
         mingw32*|win32|win64|cygwin*|*-dos|freedos|opendos|os/2*|symbian) echo .exe ;;
@@ -5388,6 +5397,7 @@ LD_PATH=$LD_PATH
 DLLTOOL=$dlltool
 WINDRES=$windres
 DEPWINDRES=$dep_cc
+DOXYGEN=$doxygen
 LDFLAGS=$LDFLAGS
 SHFLAGS=$(echo $($ldflags_filter $SHFLAGS))
 ASMSTRIPFLAGS=$ASMSTRIPFLAGS

doc/Makefile

@@ -112,7 +112,7 @@ OBJDIRS += doc/examples
 DOXY_INPUT      = $(addprefix $(SRC_PATH)/, $(INSTHEADERS) $(DOC_EXAMPLES:%$(EXESUF)=%.c) $(LIB_EXAMPLES:%$(EXESUF)=%.c))
 
 doc/doxy/html: $(SRC_PATH)/doc/Doxyfile $(SRC_PATH)/doc/doxy-wrapper.sh $(DOXY_INPUT)
-	$(M)$(SRC_PATH)/doc/doxy-wrapper.sh $(SRC_PATH) $< $(DOXY_INPUT)
+	$(M)$(SRC_PATH)/doc/doxy-wrapper.sh $(SRC_PATH) $< $(DOXYGEN) $(DOXY_INPUT)
 
 install-doc: install-html install-man
 

doc/doxy-wrapper.sh

@@ -2,10 +2,11 @@
 
 SRC_PATH="${1}"
 DOXYFILE="${2}"
+DOXYGEN="${3}"
 
-shift 2
+shift 3
 
-doxygen - <<EOF
+$DOXYGEN - <<EOF
 @INCLUDE        = ${DOXYFILE}
 INPUT           = $@
 EXAMPLE_PATH    = ${SRC_PATH}/doc/examples