[FFmpeg-devel] [PATCH v2 04/22] avformat/aviobuf: Don't use incompatible function pointer type for call

[Andreas Rheinhardt <andreas.rheinhardt@outlook.com>]

It is undefined behaviour even in cases where it works
(it works because both are pointers). Instead change
the functions involved to use the type expected by the AVIO-API
and add inline wrappers for our internal callers.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 libavformat/avio.c    | 15 +++++++++++----
 libavformat/aviobuf.c |  6 ++----
 libavformat/url.h     | 20 ++++++++++++++++----
 3 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/libavformat/avio.c b/libavformat/avio.c
index d53da5cb0c..fd40f9ce43 100644
--- a/libavformat/avio.c
+++ b/libavformat/avio.c
@@ -404,8 +404,10 @@ static inline int retry_transfer_wrapper(URLContext *h, uint8_t *buf,
     return len;
 }
 
-int ffurl_read(URLContext *h, unsigned char *buf, int size)
+int ffurl_read2(void *urlcontext, uint8_t *buf, int size)
 {
+    URLContext *h = urlcontext;
+
     if (!(h->flags & AVIO_FLAG_READ))
         return AVERROR(EIO);
     return retry_transfer_wrapper(h, buf, NULL, size, 1,
@@ -420,8 +422,10 @@ int ffurl_read_complete(URLContext *h, unsigned char *buf, int size)
                                   h->prot->url_read, NULL, 1);
 }
 
-int ffurl_write(URLContext *h, const unsigned char *buf, int size)
+int ffurl_write2(void *urlcontext, uint8_t *buf, int size)
 {
+    URLContext *h = urlcontext;
+
     if (!(h->flags & AVIO_FLAG_WRITE))
         return AVERROR(EIO);
     /* avoid sending too big packets */
@@ -432,8 +436,9 @@ int ffurl_write(URLContext *h, const unsigned char *buf, int size)
                                   NULL, h->prot->url_write, 0);
 }
 
-int64_t ffurl_seek(URLContext *h, int64_t pos, int whence)
+int64_t ffurl_seek2(void *urlcontext, int64_t pos, int whence)
 {
+    URLContext *h = urlcontext;
     int64_t ret;
 
     if (!h->prot->url_seek)
@@ -654,8 +659,10 @@ int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles)
     return h->prot->url_get_multi_file_handle(h, handles, numhandles);
 }
 
-int ffurl_get_short_seek(URLContext *h)
+int ffurl_get_short_seek(void *urlcontext)
 {
+    URLContext *h = urlcontext;
+
     if (!h || !h->prot || !h->prot->url_get_short_seek)
         return AVERROR(ENOSYS);
     return h->prot->url_get_short_seek(h);
diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
index 029a9e966b..ad5827f216 100644
--- a/libavformat/aviobuf.c
+++ b/libavformat/aviobuf.c
@@ -976,9 +976,7 @@ int ffio_fdopen(AVIOContext **s, URLContext *h)
         return AVERROR(ENOMEM);
 
     *s = avio_alloc_context(buffer, buffer_size, h->flags & AVIO_FLAG_WRITE, h,
-                            (int (*)(void *, uint8_t *, int))  ffurl_read,
-                            (int (*)(void *, uint8_t *, int))  ffurl_write,
-                            (int64_t (*)(void *, int64_t, int))ffurl_seek);
+                            ffurl_read2, ffurl_write2, ffurl_seek2);
     if (!*s) {
         av_freep(&buffer);
         return AVERROR(ENOMEM);
@@ -1006,7 +1004,7 @@ int ffio_fdopen(AVIOContext **s, URLContext *h)
         if (h->prot->url_read_seek)
             (*s)->seekable |= AVIO_SEEKABLE_TIME;
     }
-    ((FFIOContext*)(*s))->short_seek_get = (int (*)(void *))ffurl_get_short_seek;
+    ((FFIOContext*)(*s))->short_seek_get = ffurl_get_short_seek;
     (*s)->av_class = &ff_avio_class;
     return 0;
 }
diff --git a/libavformat/url.h b/libavformat/url.h
index 3cfe3ecc5c..bba1a9a1df 100644
--- a/libavformat/url.h
+++ b/libavformat/url.h
@@ -170,6 +170,7 @@ int ffurl_accept(URLContext *s, URLContext **c);
  */
 int ffurl_handshake(URLContext *c);
 
+int ffurl_read2(void *urlcontext, unsigned char *buf, int size);
 /**
  * Read up to size bytes from the resource accessed by h, and store
  * the read bytes in buf.
@@ -179,7 +180,10 @@ int ffurl_handshake(URLContext *c);
  * indicates that it is not possible to read more from the accessed
  * resource (except if the value of the size argument is also zero).
  */
-int ffurl_read(URLContext *h, unsigned char *buf, int size);
+static inline int ffurl_read(URLContext *h, uint8_t *buf, int size)
+{
+    return ffurl_read2(h, buf, size);
+}
 
 /**
  * Read as many bytes as possible (up to size), calling the
@@ -190,14 +194,19 @@ int ffurl_read(URLContext *h, unsigned char *buf, int size);
  */
 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size);
 
+int ffurl_write2(void *urlcontext, uint8_t *buf, int size);
 /**
  * Write size bytes from buf to the resource accessed by h.
  *
  * @return the number of bytes actually written, or a negative value
  * corresponding to an AVERROR code in case of failure
  */
-int ffurl_write(URLContext *h, const unsigned char *buf, int size);
+static inline int ffurl_write(URLContext *h, const uint8_t *buf, int size)
+{
+    return ffurl_write2(h, (uint8_t*)buf, size);
+}
 
+int64_t ffurl_seek2(void *urlcontext, int64_t pos, int whence);
 /**
  * Change the position that will be used by the next read/write
  * operation on the resource accessed by h.
@@ -212,7 +221,10 @@ int ffurl_write(URLContext *h, const unsigned char *buf, int size);
  * the beginning of the file. You can use this feature together with
  * SEEK_CUR to read the current file position.
  */
-int64_t ffurl_seek(URLContext *h, int64_t pos, int whence);
+static inline int64_t ffurl_seek(URLContext *h, int64_t pos, int whence)
+{
+    return ffurl_seek2(h, pos, whence);
+}
 
 /**
  * Close the resource accessed by the URLContext h, and free the
@@ -251,7 +263,7 @@ int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles);
  *
  * @return threshold (>0) on success or <=0 on error.
  */
-int ffurl_get_short_seek(URLContext *h);
+int ffurl_get_short_seek(void *urlcontext);
 
 /**
  * Signal the URLContext that we are done reading or writing the stream.
-- 
2.34.1

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