Wrap dll functions more simply

* decompress.c, gnutls.c, image.c, xml.c:
If WINDOWSNT, use '#define FOO fn_FOO' to wrap dll functions,
rather than the inverse when not WINDOWSNT.  This isolates the
fn_* business into the WINDOWSNT-specific section of the code,
which makes it easier to maintain the generic code.
* decompress.c (DEF_ZLIB_FN, LOAD_ZLIB_FN):
* gnutls.c (DEF_GNUTLS_FN, LOAD_GNUTLS_FN):
* image.c (DEF_IMGLIB_FN, LOAD_IMGLIB_FN):
* xml.c (DEF_XML2_FN, LOAD_XML2_FN):
Remove.  All uses replaced by DEF_DLL_FN.
* w32.h (DEF_DLL_FN, LOAD_DLL_FN): New macros.

1 files changed, 49 insertions, 45 deletions

diff --git a/src/xml.c b/src/xml.c
index d418202182b..6be3bc74e97 100644
--- a/src/xml.c
+++ b/src/xml.c
@@ -33,26 +33,17 @@ static Lisp_Object Qlibxml2_dll;
 
 #ifdef WINDOWSNT
 
-#include <windows.h>
-#include "w32.h"
+# include <windows.h>
+# include "w32.h"
 
-/* Macro for defining functions that will be loaded from the libxml2 DLL.  */
-#define DEF_XML2_FN(rettype,func,args) static rettype (FAR CDECL *fn_##func)args
-
-/* Macro for loading libxml2 functions from the library.  */
-#define LOAD_XML2_FN(lib,func) {                                        \
-    fn_##func = (void *) GetProcAddress (lib, #func);                   \
-    if (!fn_##func) goto bad_library;                                   \
-  }
-
-DEF_XML2_FN (htmlDocPtr, htmlReadMemory,
+DEF_DLL_FN (htmlDocPtr, htmlReadMemory,
              (const char *, int, const char *, const char *, int));
-DEF_XML2_FN (xmlDocPtr, xmlReadMemory,
+DEF_DLL_FN (xmlDocPtr, xmlReadMemory,
              (const char *, int, const char *, const char *, int));
-DEF_XML2_FN (xmlNodePtr, xmlDocGetRootElement, (xmlDocPtr));
-DEF_XML2_FN (void, xmlFreeDoc, (xmlDocPtr));
-DEF_XML2_FN (void, xmlCleanupParser, (void));
-DEF_XML2_FN (void, xmlCheckVersion, (int));
+DEF_DLL_FN (xmlNodePtr, xmlDocGetRootElement, (xmlDocPtr));
+DEF_DLL_FN (void, xmlFreeDoc, (xmlDocPtr));
+DEF_DLL_FN (void, xmlCleanupParser, (void));
+DEF_DLL_FN (void, xmlCheckVersion, (int));
 
 static int
 libxml2_loaded_p (void)
@@ -64,14 +55,33 @@ libxml2_loaded_p (void)
   return 0;
 }
 
-#else  /* !WINDOWSNT */
+# undef htmlReadMemory
+# undef xmlCheckVersion
+# undef xmlCleanupParser
+# undef xmlDocGetRootElement
+# undef xmlFreeDoc
+# undef xmlReadMemory
+
+# define htmlReadMemory fn_htmlReadMemory
+# define xmlCheckVersion fn_xmlCheckVersion
+# define xmlCleanupParser fn_xmlCleanupParser
+# define xmlDocGetRootElement fn_xmlDocGetRootElement
+# define xmlFreeDoc fn_xmlFreeDoc
+# define xmlReadMemory fn_xmlReadMemory
+
+static bool
+load_dll_functions (HMODULE library)
+{
+  LOAD_DLL_FN (library, htmlReadMemory);
+  LOAD_DLL_FN (library, xmlReadMemory);
+  LOAD_DLL_FN (library, xmlDocGetRootElement);
+  LOAD_DLL_FN (library, xmlFreeDoc);
+  LOAD_DLL_FN (library, xmlCleanupParser);
+  LOAD_DLL_FN (library, xmlCheckVersion);
+  return true;
+}
 
-#define fn_htmlReadMemory       htmlReadMemory
-#define fn_xmlReadMemory        xmlReadMemory
-#define fn_xmlDocGetRootElement xmlDocGetRootElement
-#define fn_xmlFreeDoc           xmlFreeDoc
-#define fn_xmlCleanupParser     xmlCleanupParser
-#define fn_xmlCheckVersion      xmlCheckVersion
+#else  /* !WINDOWSNT */
 
 static int
 libxml2_loaded_p (void)
@@ -97,14 +107,8 @@ init_libxml2_functions (void)
           return 0;
         }
 
-      /* LOAD_XML2_FN jumps to bad_library if it fails to find the
-         named function.  */
-      LOAD_XML2_FN (library, htmlReadMemory);
-      LOAD_XML2_FN (library, xmlReadMemory);
-      LOAD_XML2_FN (library, xmlDocGetRootElement);
-      LOAD_XML2_FN (library, xmlFreeDoc);
-      LOAD_XML2_FN (library, xmlCleanupParser);
-      LOAD_XML2_FN (library, xmlCheckVersion);
+      if (! load_dll_functions (library))
+        goto bad_library;
 
       Vlibrary_cache = Fcons (Fcons (Qlibxml2_dll, Qt), Vlibrary_cache);
       return 1;
@@ -182,7 +186,7 @@ parse_region (Lisp_Object start, Lisp_Object end, Lisp_Object base_url, Lisp_Obj
   const char *burl = "";
   ptrdiff_t istart, iend, istart_byte, iend_byte;
 
-  fn_xmlCheckVersion (LIBXML_VERSION);
+  xmlCheckVersion (LIBXML_VERSION);
 
   validate_region (&start, &end);
 
@@ -201,16 +205,16 @@ parse_region (Lisp_Object start, Lisp_Object end, Lisp_Object base_url, Lisp_Obj
     }
 
   if (htmlp)
-    doc = fn_htmlReadMemory ((char *) BYTE_POS_ADDR (istart_byte),
-                             iend_byte - istart_byte, burl, "utf-8",
-                             HTML_PARSE_RECOVER|HTML_PARSE_NONET|
-                             HTML_PARSE_NOWARNING|HTML_PARSE_NOERROR|
-                             HTML_PARSE_NOBLANKS);
+    doc = htmlReadMemory ((char *) BYTE_POS_ADDR (istart_byte),
+                          iend_byte - istart_byte, burl, "utf-8",
+                          HTML_PARSE_RECOVER|HTML_PARSE_NONET|
+                          HTML_PARSE_NOWARNING|HTML_PARSE_NOERROR|
+                          HTML_PARSE_NOBLANKS);
   else
-    doc = fn_xmlReadMemory ((char *) BYTE_POS_ADDR (istart_byte),
-                            iend_byte - istart_byte, burl, "utf-8",
-                            XML_PARSE_NONET|XML_PARSE_NOWARNING|
-                            XML_PARSE_NOBLANKS |XML_PARSE_NOERROR);
+    doc = xmlReadMemory ((char *) BYTE_POS_ADDR (istart_byte),
+                         iend_byte - istart_byte, burl, "utf-8",
+                         XML_PARSE_NONET|XML_PARSE_NOWARNING|
+                         XML_PARSE_NOBLANKS |XML_PARSE_NOERROR);
 
   if (doc != NULL)
     {
@@ -232,14 +236,14 @@ parse_region (Lisp_Object start, Lisp_Object end, Lisp_Object base_url, Lisp_Obj
       if (NILP (result)) {
         /* The document doesn't have toplevel comments or we discarded
            them.  Get the tree the proper way. */
-        xmlNode *node = fn_xmlDocGetRootElement (doc);
+        xmlNode *node = xmlDocGetRootElement (doc);
         if (node != NULL)
           result = make_dom (node);
       } else
         result = Fcons (intern ("top"),
                         Fcons (Qnil, Fnreverse (Fcons (r, result))));
 
-      fn_xmlFreeDoc (doc);
+      xmlFreeDoc (doc);
     }
 
   return result;
@@ -249,7 +253,7 @@ void
 xml_cleanup_parser (void)
 {
   if (libxml2_loaded_p ())
-    fn_xmlCleanupParser ();
+    xmlCleanupParser ();
 }
 
 DEFUN ("libxml-parse-html-region", Flibxml_parse_html_region,