Fix use of pointers to image library functions

* src/image.c (DEF_IMGLIB_FN): Add parameter rettype, use it instead
of int.  All uses adjusted.
(PNG_JMPBUF, png_load, jpeg_load, tiff_load, gif_load)
(svg_load_image): Remove casts.

2 files changed, 100 insertions, 104 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 1d14be1ab70..af76f670e6c 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2011-01-29  Andreas Schwab  <schwab@linux-m68k.org>
+
+        * image.c (DEF_IMGLIB_FN): Add parameter rettype, use it instead
+        of int.  All uses adjusted.
+        (PNG_JMPBUF, png_load, jpeg_load, tiff_load, gif_load)
+        (svg_load_image): Remove casts.
+
 2011-01-29  Chong Yidong  <cyd@stupidchicken.com>
 
         * image.c (fn_png_longjmp, fn_png_set_longjmp_fn): New png
diff --git a/src/image.c b/src/image.c
index 91b33c45507..b814b795fab 100644
--- a/src/image.c
+++ b/src/image.c
@@ -1977,7 +1977,7 @@ mark_image_cache (struct image_cache *c)
 #ifdef HAVE_NTGUI
 
 /* Macro for defining functions that will be loaded from image DLLs.  */
-#define DEF_IMGLIB_FN(func) int (FAR CDECL *fn_##func)()
+#define DEF_IMGLIB_FN(rettype, func) rettype (FAR CDECL *fn_##func)()
 
 /* Macro for loading those image functions from the library.  */
 #define LOAD_IMGLIB_FN(lib,func) {                                      \
@@ -3387,10 +3387,10 @@ xpm_free_colors (dpy, cmap, pixels, npixels, closure)
 
 /* XPM library details.  */
 
-DEF_IMGLIB_FN (XpmFreeAttributes);
-DEF_IMGLIB_FN (XpmCreateImageFromBuffer);
-DEF_IMGLIB_FN (XpmReadFileToImage);
-DEF_IMGLIB_FN (XImageFree);
+DEF_IMGLIB_FN (void, XpmFreeAttributes);
+DEF_IMGLIB_FN (int, XpmCreateImageFromBuffer);
+DEF_IMGLIB_FN (int, XpmReadFileToImage);
+DEF_IMGLIB_FN (void, XImageFree);
 
 static int
 init_xpm_functions (Lisp_Object libraries)
@@ -5568,31 +5568,31 @@ png_image_p (object)
 #ifdef HAVE_NTGUI
 /* PNG library details.  */
 
-DEF_IMGLIB_FN (png_get_io_ptr);
-DEF_IMGLIB_FN (png_sig_cmp);
-DEF_IMGLIB_FN (png_create_read_struct);
-DEF_IMGLIB_FN (png_create_info_struct);
-DEF_IMGLIB_FN (png_destroy_read_struct);
-DEF_IMGLIB_FN (png_set_read_fn);
-DEF_IMGLIB_FN (png_set_sig_bytes);
-DEF_IMGLIB_FN (png_read_info);
-DEF_IMGLIB_FN (png_get_IHDR);
-DEF_IMGLIB_FN (png_get_valid);
-DEF_IMGLIB_FN (png_set_strip_16);
-DEF_IMGLIB_FN (png_set_expand);
-DEF_IMGLIB_FN (png_set_gray_to_rgb);
-DEF_IMGLIB_FN (png_set_background);
-DEF_IMGLIB_FN (png_get_bKGD);
-DEF_IMGLIB_FN (png_read_update_info);
-DEF_IMGLIB_FN (png_get_channels);
-DEF_IMGLIB_FN (png_get_rowbytes);
-DEF_IMGLIB_FN (png_read_image);
-DEF_IMGLIB_FN (png_read_end);
-DEF_IMGLIB_FN (png_error);
+DEF_IMGLIB_FN (png_voidp, png_get_io_ptr);
+DEF_IMGLIB_FN (int, png_sig_cmp);
+DEF_IMGLIB_FN (png_structp, png_create_read_struct);
+DEF_IMGLIB_FN (png_infop, png_create_info_struct);
+DEF_IMGLIB_FN (void, png_destroy_read_struct);
+DEF_IMGLIB_FN (void, png_set_read_fn);
+DEF_IMGLIB_FN (void, png_set_sig_bytes);
+DEF_IMGLIB_FN (void, png_read_info);
+DEF_IMGLIB_FN (png_uint_32, png_get_IHDR);
+DEF_IMGLIB_FN (png_uint_32, png_get_valid);
+DEF_IMGLIB_FN (void, png_set_strip_16);
+DEF_IMGLIB_FN (void, png_set_expand);
+DEF_IMGLIB_FN (void, png_set_gray_to_rgb);
+DEF_IMGLIB_FN (void, png_set_background);
+DEF_IMGLIB_FN (png_uint_32, png_get_bKGD);
+DEF_IMGLIB_FN (void, png_read_update_info);
+DEF_IMGLIB_FN (png_byte, png_get_channels);
+DEF_IMGLIB_FN (png_size_t, png_get_rowbytes);
+DEF_IMGLIB_FN (void, png_read_image);
+DEF_IMGLIB_FN (void, png_read_end);
+DEF_IMGLIB_FN (void, png_error);
 
 #if (PNG_LIBPNG_VER >= 10500)
-DEF_IMGLIB_FN (png_longjmp);
-DEF_IMGLIB_FN (png_set_longjmp_fn);
+DEF_IMGLIB_FN (void, png_longjmp);
+DEF_IMGLIB_FN (jmp_buf *, png_set_longjmp_fn);
 #endif /* libpng version >= 1.5 */
 
 static int
@@ -5669,13 +5669,10 @@ init_png_functions (Lisp_Object libraries)
 #define PNG_LONGJMP(ptr) (longjmp ((ptr)->jmpbuf, 1))
 #define PNG_JMPBUF(ptr) ((ptr)->jmpbuf)
 #else
-/* In libpng version 1.5, the jmpbuf member is hidden.
-   We need the extra cast for PNG_JMPBUF because, for Windows,
-   DEF_IMGLIB_FN defines the return value of fn_png_set_longjmp_fn to
-   be int (Bug#7908).  */
+/* In libpng version 1.5, the jmpbuf member is hidden. (Bug#7908)  */
 #define PNG_LONGJMP(ptr) (fn_png_longjmp ((ptr), 1))
 #define PNG_JMPBUF(ptr) \
-  (*(jmp_buf *)(fn_png_set_longjmp_fn((ptr), longjmp, sizeof (jmp_buf))))
+  (*fn_png_set_longjmp_fn((ptr), longjmp, sizeof (jmp_buf)))
 #endif
 
 /* Error and warning handlers installed when the PNG library
@@ -5832,11 +5829,10 @@ png_load (f, img)
       tbr.bytes += sizeof (sig);
     }
 
-  /* Initialize read and info structs for PNG lib.  Casting return
-     value avoids a GCC warning on W32.  */
-  png_ptr = (png_structp)fn_png_create_read_struct (PNG_LIBPNG_VER_STRING,
-                                                    NULL, my_png_error,
-                                                    my_png_warning);
+  /* Initialize read and info structs for PNG lib.  */
+  png_ptr = fn_png_create_read_struct (PNG_LIBPNG_VER_STRING,
+                                       NULL, my_png_error,
+                                       my_png_warning);
   if (!png_ptr)
     {
       if (fp) fclose (fp);
@@ -5844,8 +5840,7 @@ png_load (f, img)
       return 0;
     }
 
-  /* Casting return value avoids a GCC warning on W32.  */
-  info_ptr = (png_infop)fn_png_create_info_struct (png_ptr);
+  info_ptr = fn_png_create_info_struct (png_ptr);
   if (!info_ptr)
     {
       fn_png_destroy_read_struct (&png_ptr, NULL, NULL);
@@ -5854,8 +5849,7 @@ png_load (f, img)
       return 0;
     }
 
-  /* Casting return value avoids a GCC warning on W32.  */
-  end_info = (png_infop)fn_png_create_info_struct (png_ptr);
+  end_info = fn_png_create_info_struct (png_ptr);
   if (!end_info)
     {
       fn_png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
@@ -6222,14 +6216,14 @@ jpeg_image_p (object)
 #ifdef HAVE_NTGUI
 
 /* JPEG library details.  */
-DEF_IMGLIB_FN (jpeg_CreateDecompress);
-DEF_IMGLIB_FN (jpeg_start_decompress);
-DEF_IMGLIB_FN (jpeg_finish_decompress);
-DEF_IMGLIB_FN (jpeg_destroy_decompress);
-DEF_IMGLIB_FN (jpeg_read_header);
-DEF_IMGLIB_FN (jpeg_read_scanlines);
-DEF_IMGLIB_FN (jpeg_std_error);
-DEF_IMGLIB_FN (jpeg_resync_to_restart);
+DEF_IMGLIB_FN (void, jpeg_CreateDecompress);
+DEF_IMGLIB_FN (boolean, jpeg_start_decompress);
+DEF_IMGLIB_FN (boolean, jpeg_finish_decompress);
+DEF_IMGLIB_FN (void, jpeg_destroy_decompress);
+DEF_IMGLIB_FN (int, jpeg_read_header);
+DEF_IMGLIB_FN (JDIMENSION, jpeg_read_scanlines);
+DEF_IMGLIB_FN (struct jpeg_error_mgr *, jpeg_std_error);
+DEF_IMGLIB_FN (boolean, jpeg_resync_to_restart);
 
 static int
 init_jpeg_functions (Lisp_Object libraries)
@@ -6547,9 +6541,8 @@ jpeg_load (f, img)
     }
 
   /* Customize libjpeg's error handling to call my_error_exit when an
-     error is detected.  This function will perform a longjmp.
-     Casting return value avoids a GCC warning on W32.  */
-  cinfo.err = (struct jpeg_error_mgr *)fn_jpeg_std_error (&mgr.pub);
+     error is detected.  This function will perform a longjmp.  */
+  cinfo.err = fn_jpeg_std_error (&mgr.pub);
   mgr.pub.error_exit = my_error_exit;
 
   if ((rc = setjmp (mgr.setjmp_buffer)) != 0)
@@ -6777,14 +6770,14 @@ tiff_image_p (object)
 #ifdef HAVE_NTGUI
 
 /* TIFF library details.  */
-DEF_IMGLIB_FN (TIFFSetErrorHandler);
-DEF_IMGLIB_FN (TIFFSetWarningHandler);
-DEF_IMGLIB_FN (TIFFOpen);
-DEF_IMGLIB_FN (TIFFClientOpen);
-DEF_IMGLIB_FN (TIFFGetField);
-DEF_IMGLIB_FN (TIFFReadRGBAImage);
-DEF_IMGLIB_FN (TIFFClose);
-DEF_IMGLIB_FN (TIFFSetDirectory);
+DEF_IMGLIB_FN (TIFFErrorHandler, TIFFSetErrorHandler);
+DEF_IMGLIB_FN (TIFFErrorHandler, TIFFSetWarningHandler);
+DEF_IMGLIB_FN (TIFF *, TIFFOpen);
+DEF_IMGLIB_FN (TIFF *, TIFFClientOpen);
+DEF_IMGLIB_FN (int, TIFFGetField);
+DEF_IMGLIB_FN (int, TIFFReadRGBAImage);
+DEF_IMGLIB_FN (void, TIFFClose);
+DEF_IMGLIB_FN (int, TIFFSetDirectory);
 
 static int
 init_tiff_functions (Lisp_Object libraries)
@@ -6994,9 +6987,8 @@ tiff_load (f, img)
           return 0;
         }
 
-      /* Try to open the image file.  Casting return value avoids a
-         GCC warning on W32.  */
-      tiff = (TIFF *)fn_TIFFOpen (SDATA (file), "r");
+      /* Try to open the image file.  */
+      tiff = fn_TIFFOpen (SDATA (file), "r");
       if (tiff == NULL)
         {
           image_error ("Cannot open `%s'", file, Qnil);
@@ -7011,15 +7003,14 @@ tiff_load (f, img)
       memsrc.len = SBYTES (specified_data);
       memsrc.index = 0;
 
-      /* Casting return value avoids a GCC warning on W32.  */
-      tiff = (TIFF *)fn_TIFFClientOpen ("memory_source", "r", &memsrc,
-                                        (TIFFReadWriteProc) tiff_read_from_memory,
-                                        (TIFFReadWriteProc) tiff_write_from_memory,
-                                        tiff_seek_in_memory,
-                                        tiff_close_memory,
-                                        tiff_size_of_memory,
-                                        tiff_mmap_memory,
-                                        tiff_unmap_memory);
+      tiff = fn_TIFFClientOpen ("memory_source", "r", &memsrc,
+                                (TIFFReadWriteProc) tiff_read_from_memory,
+                                (TIFFReadWriteProc) tiff_write_from_memory,
+                                tiff_seek_in_memory,
+                                tiff_close_memory,
+                                tiff_size_of_memory,
+                                tiff_mmap_memory,
+                                tiff_unmap_memory);
 
       if (!tiff)
         {
@@ -7257,10 +7248,10 @@ gif_image_p (object)
 #ifdef HAVE_NTGUI
 
 /* GIF library details.  */
-DEF_IMGLIB_FN (DGifCloseFile);
-DEF_IMGLIB_FN (DGifSlurp);
-DEF_IMGLIB_FN (DGifOpen);
-DEF_IMGLIB_FN (DGifOpenFileName);
+DEF_IMGLIB_FN (int, DGifCloseFile);
+DEF_IMGLIB_FN (int, DGifSlurp);
+DEF_IMGLIB_FN (GifFileType *, DGifOpen);
+DEF_IMGLIB_FN (GifFileType *, DGifOpenFileName);
 
 static int
 init_gif_functions (Lisp_Object libraries)
@@ -7358,9 +7349,8 @@ gif_load (f, img)
           return 0;
         }
 
-      /* Open the GIF file.  Casting return value avoids a GCC warning
-         on W32.  */
-      gif = (GifFileType *)fn_DGifOpenFileName (SDATA (file));
+      /* Open the GIF file.  */
+      gif = fn_DGifOpenFileName (SDATA (file));
       if (gif == NULL)
         {
           image_error ("Cannot open `%s'", file, Qnil);
@@ -7376,8 +7366,7 @@ gif_load (f, img)
       memsrc.len = SBYTES (specified_data);
       memsrc.index = 0;
 
-      /* Casting return value avoids a GCC warning on W32.  */
-      gif = (GifFileType *) fn_DGifOpen (&memsrc, gif_read_from_memory);
+      gif = fn_DGifOpen (&memsrc, gif_read_from_memory);
       if (!gif)
         {
           image_error ("Cannot open memory source `%s'", img->spec, Qnil);
@@ -7674,25 +7663,25 @@ svg_image_p (object)
 #ifdef HAVE_NTGUI
 
 /* SVG library functions.  */
-DEF_IMGLIB_FN (rsvg_handle_new);
-DEF_IMGLIB_FN (rsvg_handle_get_dimensions);
-DEF_IMGLIB_FN (rsvg_handle_write);
-DEF_IMGLIB_FN (rsvg_handle_close);
-DEF_IMGLIB_FN (rsvg_handle_get_pixbuf);
-DEF_IMGLIB_FN (rsvg_handle_free);
-
-DEF_IMGLIB_FN (gdk_pixbuf_get_width);
-DEF_IMGLIB_FN (gdk_pixbuf_get_height);
-DEF_IMGLIB_FN (gdk_pixbuf_get_pixels);
-DEF_IMGLIB_FN (gdk_pixbuf_get_rowstride);
-DEF_IMGLIB_FN (gdk_pixbuf_get_colorspace);
-DEF_IMGLIB_FN (gdk_pixbuf_get_n_channels);
-DEF_IMGLIB_FN (gdk_pixbuf_get_has_alpha);
-DEF_IMGLIB_FN (gdk_pixbuf_get_bits_per_sample);
-
-DEF_IMGLIB_FN (g_type_init);
-DEF_IMGLIB_FN (g_object_unref);
-DEF_IMGLIB_FN (g_error_free);
+DEF_IMGLIB_FN (RsvgHandle *, rsvg_handle_new);
+DEF_IMGLIB_FN (void, rsvg_handle_get_dimensions);
+DEF_IMGLIB_FN (gboolean, rsvg_handle_write);
+DEF_IMGLIB_FN (gboolean, rsvg_handle_close);
+DEF_IMGLIB_FN (GdkPixbuf *, rsvg_handle_get_pixbuf);
+DEF_IMGLIB_FN (void, rsvg_handle_free);
+
+DEF_IMGLIB_FN (int, gdk_pixbuf_get_width);
+DEF_IMGLIB_FN (int, gdk_pixbuf_get_height);
+DEF_IMGLIB_FN (guchar *, gdk_pixbuf_get_pixels);
+DEF_IMGLIB_FN (int, gdk_pixbuf_get_rowstride);
+DEF_IMGLIB_FN (GdkColorspace, gdk_pixbuf_get_colorspace);
+DEF_IMGLIB_FN (int, gdk_pixbuf_get_n_channels);
+DEF_IMGLIB_FN (gboolean, gdk_pixbuf_get_has_alpha);
+DEF_IMGLIB_FN (int, gdk_pixbuf_get_bits_per_sample);
+
+DEF_IMGLIB_FN (void, g_type_init);
+DEF_IMGLIB_FN (void, g_object_unref);
+DEF_IMGLIB_FN (void, g_error_free);
 
 Lisp_Object Qgdk_pixbuf, Qglib, Qgobject;
 
@@ -7846,7 +7835,7 @@ svg_load_image (f, img, contents, size)
      gnome type library functions.  */
   fn_g_type_init ();
   /* Make a handle to a new rsvg object.  */
-  rsvg_handle = (RsvgHandle *) fn_rsvg_handle_new ();
+  rsvg_handle = fn_rsvg_handle_new ();
 
   /* Parse the contents argument and fill in the rsvg_handle.  */
   fn_rsvg_handle_write (rsvg_handle, contents, size, &error);
@@ -7866,14 +7855,14 @@ svg_load_image (f, img, contents, size)
 
   /* We can now get a valid pixel buffer from the svg file, if all
      went ok.  */
-  pixbuf = (GdkPixbuf *) fn_rsvg_handle_get_pixbuf (rsvg_handle);
+  pixbuf = fn_rsvg_handle_get_pixbuf (rsvg_handle);
   if (!pixbuf) goto rsvg_error;
   fn_g_object_unref (rsvg_handle);
 
   /* Extract some meta data from the svg handle.  */
   width     = fn_gdk_pixbuf_get_width (pixbuf);
   height    = fn_gdk_pixbuf_get_height (pixbuf);
-  pixels    = (const guint8 *) fn_gdk_pixbuf_get_pixels (pixbuf);
+  pixels    = fn_gdk_pixbuf_get_pixels (pixbuf);
   rowstride = fn_gdk_pixbuf_get_rowstride (pixbuf);
 
   /* Validate the svg meta data.  */