Commit: 558e2a9d2b6f8e32c6051ad160dbaadfdb211e21 - mingw-locale-info (git)

A tool to display MS-Windows locale information

Commit MetaInfo

• Revision: 558e2a9d2b6f8e32c6051ad160dbaadfdb211e21 (tree)
• Time: 2019-03-05 06:59:17
• Author: Keith Marshall <keith@user...>
• Commiter: Keith Marshall

Log Message

Segregate Windows version dependencies into a DLL.

* locale-info.c [BUILD_DLL] (query_locale_info): Compile it, and all
of its supporting static functions, as an exported function, which is
to be encapsulated within an arbitrarily named DLL.
[! BUILD_DLL] (main): Compile this function only; use LoadLibrary(),
and GetProcAddress(), to direct execution to the query_locale_info()
function, assuming that this has been compiled into a DLL named...
* locale-info.dll: ...thus.

Change Summary

• modified: locale-info.c

Incremental Difference

--- a/locale-info.c
+++ b/locale-info.c
@@ -55,6 +55,14 @@
  * Compile time options:
  *   In addition to the usual GCC options, users may choose to enable:
  *
+ *   -D BUILD_DLL -shared	   Build the DLL component of the
+ *				   application.  The application must
+ *				   be compiled and linked twice; once
+ *				   with BOTH of these options, and
+ *				   again with NEITHER, to build the
+ *				   DLL and main EXE components of
+ *				   the application respectively.
+ *
  *   -D SETLOCALE		   Enables synchronization of the CRT
  *   				   locale with the specified Windows
  *   				   locale.
@@ -76,6 +84,12 @@ static const char *error = "Error ***";
 #include <winbase.h>
 #include <stdlib.h>
 
+/* The primary duty of the application is served by a DLL component...
+ */
+#if BUILD_DLL
+/* ...which is compiled in this case; (it is assumed that the -shared
+ * option is also specified, for the compile and link).
+ */
 #include <limits.h>
 #include <unistd.h>
 #include <winnls.h>
@@ -156,6 +170,7 @@ static int build_locale_string( wchar_t delim, int offset, int category )
 }
 #endif
 
+__declspec(dllexport)
 int query_locale_info( int argc, char **argv )
 {
   unsigned int base = 0, span = UINT_MAX >> 4;
@@ -261,7 +276,6 @@ int query_locale_info( int argc, char **argv )
       return EXIT_FAILURE;
     }
   }
-
   /* Finally, cycle over the specified key value range, performing
    * the specified look-up action, ensuring that we do not wrap at
    * UINT_MAX, into an interminable loop.
@@ -272,8 +286,17 @@ int query_locale_info( int argc, char **argv )
   return EXIT_SUCCESS;
 }
 
+#else	/* ! BUILD_DLL */
+/* When not building the DLL component, we simply furnish the main()
+ * function; this checks that the necessary GetLocaleInfoEx() function
+ * is actually present within kernel32.dll, (it isn't, on any Windows
+ * version pre-dating Vista), before delegating the actual query to
+ * the handler in the supporting DLL component.
+ */
 int main( int argc, char **argv )
 {
+  typedef int (*query)( int, char ** );
+
   HMODULE ref; const char *api = "kernel32.dll";
   if( (ref = GetModuleHandleA( api )) != NULL )
   {
@@ -282,10 +305,22 @@ int main( int argc, char **argv )
       errprintf( "function '%s' is unsupported on this host\n", api );
       errprintf( "Windows-Vista (or later) is required\n" );
     }
-    else return query_locale_info( argc, argv );
+    else if( (ref = LoadLibraryA( api = "locale-info.dll" )) == NULL )
+      errprintf( "cannot load '%s'\n", api );
+
+    else
+    { api = "query_locale_info";
+      query locale_info = (query)(GetProcAddress( ref, api ));
+      if( locale_info == NULL )
+	errprintf( "cannot access '%s()' API\n", api );
+
+      else return locale_info( argc, argv );
+    }
   }
   else errprintf( "'%s' was not mapped within this process\n", api );
   return EXIT_FAILURE;
 }
 
+#endif	/* ! BUILD_DLL */
+
 /* $RCSfile$: end of file */