crate: improve link attributes and allow static linking

sys/Cargo.toml

@@ -15,6 +15,7 @@ libc = "*"
 [features]
 default  = ["avcodec", "avdevice", "avfilter", "avformat", "avresample", "postproc", "swresample", "swscale"]
 
+static     = []
 avcodec    = []
 avdevice   = ["avformat"]
 avfilter   = []

sys/src/avcodec/codec.rs

@@ -1315,7 +1315,6 @@ pub enum AVLockOp {
 	AV_LOCK_DESTROY,
 }
 
-#[link(name = "avcodec")]
 extern {
 	pub fn av_codec_get_pkt_timebase(avctx: *const AVCodecContext) -> AVRational;
 	pub fn av_codec_set_pkt_timebase(avctx: *mut AVCodecContext, val: AVRational);

sys/src/avcodec/dv_profile.rs

@@ -25,7 +25,6 @@ pub struct AVDVProfile {
 	pub audio_shuffle: [*const uint8_t; 9],
 }
 
-#[link(name = "avcodec")]
 extern {
 	pub fn av_dv_frame_profile(sys: *const AVDVProfile, frame: *const uint8_t, buf_size: c_uint) -> *const AVDVProfile;
 	pub fn av_dv_codec_profile(width: c_int, height: c_int, pix_fmt: AVPixelFormat) -> *const AVDVProfile;

sys/src/avcodec/fft.rs

@@ -33,7 +33,6 @@ pub enum DCTTransformType {
 
 pub type DCTContext = c_void;
 
-#[link(name = "avcodec")]
 extern {
 	pub fn av_fft_init(nbits: c_int, inverse: c_int) -> *mut FFTContext;
 	pub fn av_fft_permute(s: *mut FFTContext, z: *mut FFTComplex);

sys/src/avcodec/mod.rs

@@ -35,3 +35,7 @@ pub use self::vobis_parser::*;
 
 mod xvmc;
 pub use self::xvmc::*;
+
+#[cfg_attr(feature = "static", link(name = "avcodec", kind = "static"))]
+#[cfg_attr(not(feature = "static"), link(name = "avcodec"))]
+extern { }

sys/src/avcodec/qsv.rs

@@ -9,7 +9,6 @@ pub struct AVQSVContext {
 	pub nb_ext_buffers: c_int,
 }
 
-#[link(name = "avcodec")]
 extern {
 	pub fn av_qsv_alloc_context() -> *mut AVQSVContext;
 }

sys/src/avcodec/vda.rs

@@ -23,7 +23,6 @@ pub struct AVVDAContext {
 	pub output_callback: extern fn(*mut c_void, *mut c_void, i32, uint32_t, *mut c_void),
 }
 
-#[link(name = "avcodec")]
 extern {
 	pub fn ff_vda_create_decoder(vda_ctx: *mut vda_context, extradata: *mut uint8_t, extradata_size: c_int) -> c_int;
 	pub fn ff_vda_destroy_decoder(vda_ctx: *mut vda_context) -> c_int;

sys/src/avcodec/vobis_parser.rs

@@ -6,7 +6,6 @@ pub const VORBIS_FLAG_HEADER:  c_int = 0x00000001;
 pub const VORBIS_FLAG_COMMENT: c_int = 0x00000002;
 pub const VORBIS_FLAG_SETUP:   c_int = 0x00000004;
 
-#[link(name = "avcodec")]
 extern {
 	pub fn av_vorbis_parse_init(extradata: *const uint8_t, extradata_size: c_int) -> *mut AVVorbisParseContext;
 	pub fn av_vorbis_parse_free(s: *mut *mut AVVorbisParseContext);

sys/src/avdevice/device.rs

@@ -78,7 +78,6 @@ pub struct AVDeviceInfoList {
 	pub default_device: c_int,
 }
 
-#[link(name = "avdevice")]
 extern {
 	pub static av_device_capabilities: *const AVOption;
 

sys/src/avdevice/mod.rs

@@ -1,2 +1,6 @@
 mod device;
 pub use self::device::*;
+
+#[cfg_attr(feature = "static", link(name = "avdevice", kind = "static"))]
+#[cfg_attr(not(feature = "static"), link(name = "avdevice"))]
+extern { }

sys/src/avfilter/buffersink.rs

@@ -19,7 +19,6 @@ pub struct AVABufferSinkParams {
 	pub sample_rates: *mut c_int,
 }
 
-#[link(name = "avfilter")]
 extern {
 	pub fn av_buffersink_get_frame_flags(ctx: *mut AVFilterContext, frame: *mut AVFrame, flags: c_int) -> c_int;
 

sys/src/avfilter/buffersrc.rs

@@ -7,7 +7,6 @@ pub const AV_BUFFERSRC_FLAG_NO_COPY:         c_int = 2;
 pub const AV_BUFFERSRC_FLAG_PUSH:            c_int = 4;
 pub const AV_BUFFERSRC_FLAG_KEEP_REF:        c_int = 8;
 
-#[link(name = "avfilter")]
 extern {
 	pub fn av_buffersrc_add_ref(buffer_src: *mut AVFilterContext, picref: *mut AVFilterBufferRef, flags: c_int) -> c_int;
 	pub fn av_buffersrc_get_nb_failed_requests(buffer_src: *mut AVFilterContext) -> c_uint;

sys/src/avfilter/filter.rs

@@ -219,7 +219,6 @@ pub struct AVFilterInOut {
 	pub next: *mut AVFilterInOut,
 }
 
-#[link(name = "avfilter")]
 extern {
 	pub fn avfilter_version() -> c_uint;
 	pub fn avfilter_configuration() -> *const c_char;

sys/src/avfilter/mod.rs

@@ -6,3 +6,7 @@ pub use self::buffersink::*;
 
 mod buffersrc;
 pub use self::buffersrc::*;
+
+#[cfg_attr(feature = "static", link(name = "avfilter", kind = "static"))]
+#[cfg_attr(not(feature = "static"), link(name = "avfilter"))]
+extern { }

sys/src/avformat/format.rs

@@ -433,7 +433,6 @@ pub const AVSEEK_FLAG_BYTE:     c_int = 2;
 pub const AVSEEK_FLAG_ANY:      c_int = 4;
 pub const AVSEEK_FLAG_FRAME:    c_int = 8;
 
-#[link(name = "avformat")]
 extern {
 	pub fn av_get_packet(s: *mut AVIOContext, pkt: *mut AVPacket, size: c_int) -> c_int;
 	pub fn av_append_packet(s: *mut AVIOContext, pkt: *mut AVPacket, size: c_int) -> c_int;

sys/src/avformat/io.rs

@@ -93,7 +93,6 @@ pub unsafe fn avio_tell(s: *mut AVIOContext) -> int64_t {
 	avio_seek(s, 0, SEEK_CUR)
 }
 
-#[link(name = "avformat")]
 extern {
 	pub fn avio_find_protocol_name(url: *const c_char) -> *const c_char;
 	pub fn avio_check(url: *const c_char, flags: c_int) -> c_int;

sys/src/avformat/mod.rs

@@ -3,3 +3,7 @@ pub use self::format::*;
 
 mod io;
 pub use self::io::*;
+
+#[cfg_attr(feature = "static", link(name = "avformat", kind = "static"))]
+#[cfg_attr(not(feature = "static"), link(name = "avformat"))]
+extern { }

sys/src/avresample/mod.rs

@@ -3,3 +3,7 @@ pub use self::resample::*;
 pub use self::resample::AVMixCoeffType::*;
 pub use self::resample::AVResampleFilterType::*;
 pub use self::resample::AVResampleDitherMethod::*;
+
+#[cfg_attr(feature = "static", link(name = "avresample", kind = "static"))]
+#[cfg_attr(not(feature = "static"), link(name = "avresample"))]
+extern { }

sys/src/avresample/resample.rs

@@ -33,7 +33,6 @@ pub enum AVResampleDitherMethod {
 	AV_RESAMPLE_DITHER_NB,
 }
 
-#[link(name = "avresample")]
 extern {
 	pub fn avresample_version() -> c_uint;
 	pub fn avresample_configuration() -> *const c_char;

sys/src/avutil/adler32.rs

@@ -1,6 +1,5 @@
 use libc::{c_int, c_ulong, uint8_t};
 
-#[link(name = "avutil")]
 extern {
 	pub fn av_adler32_update(adler: c_ulong, buf: *const uint8_t, len: c_int) -> c_ulong;
 }