[devel]

Added some commentary about PNG_EXPORT in png.h and pngconf.h

ANNOUNCE

@@ -1,5 +1,5 @@
 
-Libpng 1.5.0beta56 - December 5, 2010
+Libpng 1.5.0beta56 - December 6, 2010
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -226,7 +226,7 @@ version 1.5.0beta24 [May 7, 2010]
     offset of the png_ptr->rowbuf pointer into png_ptr->big_row_buf.
   Added more blank lines for readability.
 
-version 1.5.0beta25 [December 5, 2010]
+version 1.5.0beta25 [December 6, 2010]
   In pngpread.c: png_push_have_row() add check for new_row > height
   Removed the now-redundant check for out-of-bounds new_row from example.c
 
@@ -451,8 +451,9 @@ Version 1.5.0beta55 [November 21, 2010]
     with pngwio.c and pngwutil.c because the 'write' callback and zlib
     compression both fail to declare their input buffers with 'const'.
 
-Version 1.5.0beta56 [December 5, 2010]
+Version 1.5.0beta56 [December 6, 2010]
   Added the private PNG_UNUSED() macro definition in pngpriv.h.
+  Added some commentary about PNG_EXPORT in png.h and pngconf.h
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
 (subscription required; visit

CHANGES

@@ -3089,8 +3089,9 @@ Version 1.5.0beta55 [November 21, 2010]
     with pngwio.c and pngwutil.c because the 'write' callback and zlib
     compression both fail to declare their input buffers with 'const'.
 
-Version 1.5.0beta56 [December 5, 2010]
+Version 1.5.0beta56 [December 6, 2010]
   Added the private PNG_UNUSED() macro definition in pngpriv.h.
+  Added some commentary about PNG_EXPORT in png.h and pngconf.h
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

png.h

@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.5.0beta56 - November 25, 2010
+ * libpng version 1.5.0beta56 - December 6, 2010
  * Copyright (c) 1998-2010 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -11,7 +11,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.5.0beta56 - November 25, 2010: Glenn
+ *   libpng versions 0.97, January 1998, through 1.5.0beta56 - December 6, 2010: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -173,7 +173,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.5.0beta56, November 25, 2010, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.5.0beta56, December 6, 2010, are
  * Copyright (c) 2004, 2006-2010 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.2.5
  * with the following individual added to the list of Contributing Authors:
@@ -285,7 +285,7 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    November 25, 2010
+ *    December 6, 2010
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
@@ -349,7 +349,7 @@
 /* Version information for png.h - this should match the version in png.c */
 #define PNG_LIBPNG_VER_STRING "1.5.0beta56"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.5.0beta56 - November 25, 2010\n"
+     " libpng version 1.5.0beta56 - December 6, 2010\n"
 
 #define PNG_LIBPNG_VER_SONUM   15
 #define PNG_LIBPNG_VER_DLLNUM  15
@@ -882,6 +882,21 @@ typedef png_struct FAR * FAR * png_structpp;
  * the place to find out how to use libpng.  See libpng-manual.txt for the
  * full explanation, see example.c for the summary.  This just provides
  * a simple one line description of the use of each function.
+ *
+ * The PNG_EXPORT macro used below is defined in pngconf.h and in
+ * the *.dfn files in the scripts directory.
+ *
+ *   PNG_EXPORT(type, name, (args), [attributes], ordinal);
+ *
+ *       type:       return type of the function
+ *       name:       function name
+ *       args:       function arguments, with types
+ *       attributes: optional function attributes
+ *       ordinal:    ordinal that is used while building
+ *                   *.def files. The ordinal value is only
+ *                   relevant when preprocessing png.h with
+ *                   the *.dfn files for building symbol table
+ *                   entries.
  */
 
 /* Returns the version number of the library */

pngconf.h

@@ -69,7 +69,8 @@
  * below) but still have compiler specific implementations, others
  * may be changed on a per-file basis when compiling against libpng.
  */
-/* This macro protects us against machines that don't have function
+
+/* The PNGARG macro protects us against machines that don't have function
  * prototypes (ie K&R style headers).  If your compiler does not handle
  * function prototypes, define this macro and use the included ansi2knr.
  * I've always been able to use _NO_PROTO as the indicator, but you may
@@ -306,7 +307,8 @@
 
 #ifndef PNG_EXPORT
    /* The ordinal value is only relevant when preprocessing png.h for symbol
-    * table entries.
+    * table entries, so we discard it here.  See the .dfn files in the
+    * scripts directory.
     */
 #  define PNG_EXPORT(type, name, args, attributes, ordinal)\
       extern PNG_FUNCTION(PNG_EXPORT_TYPE(type),(PNGAPI name),PNGARG(args),\