make class lookup more reliable

ChangeLog

@@ -1,3 +1,13 @@
+2019-02-14  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/GSPrivate.h:
+	* Source/NSBundle.m:
+	* Source/NSPathUtilities.m:
+	* Source/objc-load.m:
+	GSPrivateSymbolPath() simplified by removing the unused argument
+	and consolidated code so that, if the class lookup via dladdr()
+	fails, we fall back to use __objc_dynamic_get_symbol_path().
+
 2019-02-14  Richard Frith-Macdonald <rfm@gnu.org>
 
 	* Source/Additions/GSMime.m: Fix encoded word encoding specifier

Source/GSPrivate.h

@@ -501,16 +501,12 @@ GSPrivateStrExternalize(GSStr s) GS_ATTRIB_PRIVATE;
  * argv[0] (which might be something as horrible as './obj/test')
  * for classes in the main executable.
  *
- * If theCategory argument is not NULL, GSPrivateSymbolPath() will return
- * the filesystem path to the module from which the category theCategory
- * of the class theClass was loaded.
- *
  * Currently, the function will return nil if any of the following
  * conditions is satisfied:
  *  - the required functionality is not available on the platform we are
  *    running on;
  *  - memory allocation fails;
- *  - the symbol for that class/category could not be found.
+ *  - the symbol for that class could not be found.
  *
  * In general, if the function returns nil, it means something serious
  * went wrong in the system preventing it from getting the symbol path.
@@ -521,7 +517,7 @@ GSPrivateStrExternalize(GSStr s) GS_ATTRIB_PRIVATE;
  * runtime ... as far as I know.
  */
 NSString *
-GSPrivateSymbolPath (Class theClass, Category *theCategory) GS_ATTRIB_PRIVATE;
+GSPrivateSymbolPath(Class theClass) GS_ATTRIB_PRIVATE;
 
 /* Combining class for composite unichars
  */

Source/NSBundle.m

@@ -724,7 +724,7 @@ _find_main_bundle_for_tool(NSString *toolName)
        * really universal way of getting the framework path ... we can
        * locate the framework no matter where it is on disk!
        */
-      bundlePath = GSPrivateSymbolPath (frameworkClass, NULL);
+      bundlePath = GSPrivateSymbolPath(frameworkClass);
 
       if ([bundlePath isEqualToString: GSPrivateExecutablePath()])
 	{
@@ -1078,7 +1078,7 @@ _bundle_load_callback(Class theClass, struct objc_category *theCategory)
       _emptyTable = [NSDictionary new];
 
       /* Create basic mapping dictionaries for bootstrapping and
-       * for use if the full ductionaries can't be loaded from the
+       * for use if the full dictionaries can't be loaded from the
        * gnustep-base library resource bundle.
        */
       langAliases = [[NSDictionary alloc] initWithObjectsAndKeys:
@@ -1513,7 +1513,7 @@ _bundle_load_callback(Class theClass, struct objc_category *theCategory)
 
   [load_lock lock];
   /* Try lookup ... if not found, make sure that all loaded bundles have
-   * class->bundle mapp entries set up and check again.
+   * class->bundle map entries set up and check again.
    */
   bundle = (NSBundle *)NSMapGet(_byClass, aClass);
   if ((id)bundle == (id)[NSNull null])
@@ -1561,7 +1561,7 @@ _bundle_load_callback(Class theClass, struct objc_category *theCategory)
 	   * convert it to the format for a library name as used for
 	   * obtaining a library resource bundle.
 	   */
-	  lib = GSPrivateSymbolPath (aClass, NULL);
+	  lib = GSPrivateSymbolPath(aClass);
 	  if ([lib isEqual: GSPrivateExecutablePath()] == YES)
 	    {
 	      lib = nil;	// In program, not library.
@@ -2707,7 +2707,7 @@ IF_NO_GC(
     }
   if (self->_bundleType == NSBUNDLE_LIBRARY)
     {
-      return GSPrivateSymbolPath ([self principalClass], NULL);
+      return GSPrivateSymbolPath([self principalClass]);
     }
   object = [[self infoDictionary] objectForKey: @"NSExecutable"];
   if (object == nil || [object length] == 0)

Source/NSPathUtilities.m

@@ -961,7 +961,7 @@ GNUstepConfig(NSDictionary *newConfig)
 		{
 		  Class		c = [NSProcessInfo class];
 
-		  path = GSPrivateSymbolPath (c, 0);
+		  path = GSPrivateSymbolPath(c);
 		  // Remove library name from path
 		  path = [path stringByDeletingLastPathComponent];
                   if ([file hasPrefix: @"./"] == YES)

Source/objc-load.m

@@ -246,12 +246,11 @@ GSPrivateUnloadModule(FILE *errorStream,
 // dladdr() wrapping this function, so we no longer need a Windows-only code
 // path
 NSString *
-GSPrivateSymbolPath(Class theClass, Category *theCategory)
+GSPrivateSymbolPath(Class theClass)
 {
   unichar buf[MAX_PATH];
   NSString *s = nil;
   MEMORY_BASIC_INFORMATION memInfo;
-  NSCAssert(!theCategory, @"GSPrivateSymbolPath doesn't support categories");
 
   VirtualQueryEx(GetCurrentProcess(), theClass, &memInfo, sizeof(memInfo));
   if (GetModuleFileNameW(memInfo.AllocationBase, buf, sizeof(buf)))
@@ -263,32 +262,31 @@ GSPrivateSymbolPath(Class theClass, Category *theCategory)
     }
   return s;
 }
-#elif LINKER_GETSYMBOL 
-NSString *GSPrivateSymbolPath(Class theClass, Category *theCategory)
+#else
+NSString *GSPrivateSymbolPath(Class theClass)
 {
-  void *addr = (NULL == theCategory) ? (void*)theClass : (void*)theCategory;
+#if LINKER_GETSYMBOL 
   Dl_info info;
 
   /* This is correct: dladdr() does the opposite thing to all other UNIX
    * functions.
+   * On success, return the results, otherwise fall back to use the
+   * __objc_dynamic_get_symbol_path() function.
    */
-  if (0 == dladdr(addr, &info))
+  if (0 != dladdr((void*)theClass, &info))
     {
-      return nil;
-    }
       return [NSString stringWithUTF8String: info.dli_fname];
     }
-#else
-NSString *
-GSPrivateSymbolPath(Class theClass, Category *theCategory)
+#endif
+
+  if (theClass != nil)
     {
       const char        *ret;
-  char        buf[125], *p = buf;
+      char              buf[125];
+      char              *p = buf;
       const char        *className = class_getName(theClass);
       int               len = strlen(className);
 
-  if (theCategory == NULL)
-    {
       if (len + sizeof(char)*19 > sizeof(buf))
         {
           p = malloc(len + sizeof(char)*19);
@@ -302,29 +300,6 @@ GSPrivateSymbolPath(Class theClass, Category *theCategory)
 
       memcpy(p, "__objc_class_name_", sizeof(char)*18);
       memcpy(&p[18*sizeof(char)], className, strlen(className) + 1);
-    }
-  else
-    {
-      len += strlen(theCategory->category_name);
-
-      if (len + sizeof(char)*23 > sizeof(buf))
-	{
-	  p = malloc(len + sizeof(char)*23);
-
-	  if (p == NULL)
-	    {
-	      fprintf(stderr, "Unable to allocate memory !!");
-	      return nil;
-	    }
-	}
-
-      memcpy(p, "__objc_category_name_", sizeof(char)*21);
-      memcpy(&p[21*sizeof(char)], theCategory->class_name,
-        strlen(theCategory->class_name) + 1);
-      memcpy(&p[strlen(p)], "_", 2*sizeof(char));
-      memcpy(&p[strlen(p)], theCategory->category_name,
-        strlen(theCategory->category_name) + 1);
-    }
 
       ret = __objc_dynamic_get_symbol_path(0, p);
 
@@ -337,7 +312,7 @@ GSPrivateSymbolPath(Class theClass, Category *theCategory)
         {
           return [NSString stringWithUTF8String: ret];
         }
-
+    }
   return nil;
 }
 #endif