simplify WEBP_EXTERN macro

including the type in the macro doesn't bring much benefit to ordering,
current platforms work with a prefix, this would be insufficient if the
attribute needed to follow the function prototype. this form makes it
easier to override on the command line.

BUG=webp:355

Change-Id: Iba41ec0bb319403054be0e899c4cc472dd932fd9

src/webp/demux.h

@@ -71,7 +71,7 @@ typedef struct WebPAnimDecoderOptions WebPAnimDecoderOptions;
 
 // Returns the version number of the demux library, packed in hexadecimal using
 // 8bits for each of major/minor/revision. E.g: v2.5.7 is 0x020507.
-WEBP_EXTERN(int) WebPGetDemuxVersion(void);
+WEBP_EXTERN int WebPGetDemuxVersion(void);
 
 //------------------------------------------------------------------------------
 // Life of a Demux object
@@ -85,7 +85,7 @@ typedef enum WebPDemuxState {
 } WebPDemuxState;
 
 // Internal, version-checked, entry point
-WEBP_EXTERN(WebPDemuxer*) WebPDemuxInternal(
+WEBP_EXTERN WebPDemuxer* WebPDemuxInternal(
     const WebPData*, int, WebPDemuxState*, int);
 
 // Parses the full WebP file given by 'data'. For single images the WebP file
@@ -109,7 +109,7 @@ static WEBP_INLINE WebPDemuxer* WebPDemuxPartial(
 }
 
 // Frees memory associated with 'dmux'.
-WEBP_EXTERN(void) WebPDemuxDelete(WebPDemuxer* dmux);
+WEBP_EXTERN void WebPDemuxDelete(WebPDemuxer* dmux);
 
 //------------------------------------------------------------------------------
 // Data/information extraction.
@@ -129,7 +129,7 @@ typedef enum WebPFormatFeature {
 // Get the 'feature' value from the 'dmux'.
 // NOTE: values are only valid if WebPDemux() was used or WebPDemuxPartial()
 // returned a state > WEBP_DEMUX_PARSING_HEADER.
-WEBP_EXTERN(uint32_t) WebPDemuxGetI(
+WEBP_EXTERN uint32_t WebPDemuxGetI(
     const WebPDemuxer* dmux, WebPFormatFeature feature);
 
 //------------------------------------------------------------------------------
@@ -159,20 +159,20 @@ struct WebPIterator {
 // Returns false if 'dmux' is NULL or frame 'frame_number' is not present.
 // Call WebPDemuxReleaseIterator() when use of the iterator is complete.
 // NOTE: 'dmux' must persist for the lifetime of 'iter'.
-WEBP_EXTERN(int) WebPDemuxGetFrame(
+WEBP_EXTERN int WebPDemuxGetFrame(
     const WebPDemuxer* dmux, int frame_number, WebPIterator* iter);
 
 // Sets 'iter->fragment' to point to the next ('iter->frame_num' + 1) or
 // previous ('iter->frame_num' - 1) frame. These functions do not loop.
 // Returns true on success, false otherwise.
-WEBP_EXTERN(int) WebPDemuxNextFrame(WebPIterator* iter);
-WEBP_EXTERN(int) WebPDemuxPrevFrame(WebPIterator* iter);
+WEBP_EXTERN int WebPDemuxNextFrame(WebPIterator* iter);
+WEBP_EXTERN int WebPDemuxPrevFrame(WebPIterator* iter);
 
 // Releases any memory associated with 'iter'.
 // Must be called before any subsequent calls to WebPDemuxGetChunk() on the same
 // iter. Also, must be called before destroying the associated WebPDemuxer with
 // WebPDemuxDelete().
-WEBP_EXTERN(void) WebPDemuxReleaseIterator(WebPIterator* iter);
+WEBP_EXTERN void WebPDemuxReleaseIterator(WebPIterator* iter);
 
 //------------------------------------------------------------------------------
 // Chunk iteration.
@@ -197,20 +197,20 @@ struct WebPChunkIterator {
 // payloads are accessed through WebPDemuxGetFrame() and related functions.
 // Call WebPDemuxReleaseChunkIterator() when use of the iterator is complete.
 // NOTE: 'dmux' must persist for the lifetime of the iterator.
-WEBP_EXTERN(int) WebPDemuxGetChunk(const WebPDemuxer* dmux,
-                                   const char fourcc[4], int chunk_number,
-                                   WebPChunkIterator* iter);
+WEBP_EXTERN int WebPDemuxGetChunk(const WebPDemuxer* dmux,
+                                  const char fourcc[4], int chunk_number,
+                                  WebPChunkIterator* iter);
 
 // Sets 'iter->chunk' to point to the next ('iter->chunk_num' + 1) or previous
 // ('iter->chunk_num' - 1) chunk. These functions do not loop.
 // Returns true on success, false otherwise.
-WEBP_EXTERN(int) WebPDemuxNextChunk(WebPChunkIterator* iter);
-WEBP_EXTERN(int) WebPDemuxPrevChunk(WebPChunkIterator* iter);
+WEBP_EXTERN int WebPDemuxNextChunk(WebPChunkIterator* iter);
+WEBP_EXTERN int WebPDemuxPrevChunk(WebPChunkIterator* iter);
 
 // Releases any memory associated with 'iter'.
 // Must be called before destroying the associated WebPDemuxer with
 // WebPDemuxDelete().
-WEBP_EXTERN(void) WebPDemuxReleaseChunkIterator(WebPChunkIterator* iter);
+WEBP_EXTERN void WebPDemuxReleaseChunkIterator(WebPChunkIterator* iter);
 
 //------------------------------------------------------------------------------
 // WebPAnimDecoder API
@@ -252,7 +252,7 @@ struct WebPAnimDecoderOptions {
 };
 
 // Internal, version-checked, entry point.
-WEBP_EXTERN(int) WebPAnimDecoderOptionsInitInternal(
+WEBP_EXTERN int WebPAnimDecoderOptionsInitInternal(
     WebPAnimDecoderOptions*, int);
 
 // Should always be called, to initialize a fresh WebPAnimDecoderOptions
@@ -266,7 +266,7 @@ static WEBP_INLINE int WebPAnimDecoderOptionsInit(
 }
 
 // Internal, version-checked, entry point.
-WEBP_EXTERN(WebPAnimDecoder*) WebPAnimDecoderNewInternal(
+WEBP_EXTERN WebPAnimDecoder* WebPAnimDecoderNewInternal(
     const WebPData*, const WebPAnimDecoderOptions*, int);
 
 // Creates and initializes a WebPAnimDecoder object.
@@ -301,8 +301,8 @@ struct WebPAnimInfo {
 //   info - (out) global information fetched from the animation.
 // Returns:
 //   True on success.
-WEBP_EXTERN(int) WebPAnimDecoderGetInfo(const WebPAnimDecoder* dec,
-                                        WebPAnimInfo* info);
+WEBP_EXTERN int WebPAnimDecoderGetInfo(const WebPAnimDecoder* dec,
+                                       WebPAnimInfo* info);
 
 // Fetch the next frame from 'dec' based on options supplied to
 // WebPAnimDecoderNew(). This will be a fully reconstructed canvas of size
@@ -316,8 +316,8 @@ WEBP_EXTERN(int) WebPAnimDecoderGetInfo(const WebPAnimDecoder* dec,
 // Returns:
 //   False if any of the arguments are NULL, or if there is a parsing or
 //   decoding error, or if there are no more frames. Otherwise, returns true.
-WEBP_EXTERN(int) WebPAnimDecoderGetNext(WebPAnimDecoder* dec,
-                                        uint8_t** buf, int* timestamp);
+WEBP_EXTERN int WebPAnimDecoderGetNext(WebPAnimDecoder* dec,
+                                       uint8_t** buf, int* timestamp);
 
 // Check if there are more frames left to decode.
 // Parameters:
@@ -325,7 +325,7 @@ WEBP_EXTERN(int) WebPAnimDecoderGetNext(WebPAnimDecoder* dec,
 // Returns:
 //   True if 'dec' is not NULL and some frames are yet to be decoded.
 //   Otherwise, returns false.
-WEBP_EXTERN(int) WebPAnimDecoderHasMoreFrames(const WebPAnimDecoder* dec);
+WEBP_EXTERN int WebPAnimDecoderHasMoreFrames(const WebPAnimDecoder* dec);
 
 // Resets the WebPAnimDecoder object, so that next call to
 // WebPAnimDecoderGetNext() will restart decoding from 1st frame. This would be
@@ -333,7 +333,7 @@ WEBP_EXTERN(int) WebPAnimDecoderHasMoreFrames(const WebPAnimDecoder* dec);
 // info.loop_count times) without destroying and recreating the 'dec' object.
 // Parameters:
 //   dec - (in/out) decoder instance to be reset
-WEBP_EXTERN(void) WebPAnimDecoderReset(WebPAnimDecoder* dec);
+WEBP_EXTERN void WebPAnimDecoderReset(WebPAnimDecoder* dec);
 
 // Grab the internal demuxer object.
 // Getting the demuxer object can be useful if one wants to use operations only
@@ -343,13 +343,13 @@ WEBP_EXTERN(void) WebPAnimDecoderReset(WebPAnimDecoder* dec);
 //
 // Parameters:
 //   dec - (in) decoder instance from which the demuxer object is to be fetched.
-WEBP_EXTERN(const WebPDemuxer*) WebPAnimDecoderGetDemuxer(
+WEBP_EXTERN const WebPDemuxer* WebPAnimDecoderGetDemuxer(
     const WebPAnimDecoder* dec);
 
 // Deletes the WebPAnimDecoder object.
 // Parameters:
 //   dec - (in/out) decoder instance to be deleted
-WEBP_EXTERN(void) WebPAnimDecoderDelete(WebPAnimDecoder* dec);
+WEBP_EXTERN void WebPAnimDecoderDelete(WebPAnimDecoder* dec);
 
 #ifdef __cplusplus
 }    // extern "C"