objc-exception.h: New file.

	* objc/objc-exception.h: New file.
	* exception.c (objc_set_uncaught_exception_handler): Implemented.
	(objc_set_exception_matcher): Implemented.
	(objc_exception_throw): Use the uncaught exception handler if set.
	(PERSONALITY_FUNCTION): Use the exception matcher instead of the
	hardcoded isKindOf.
	(isKindOf): Renamed to is_kind_of_exception_matcher.  Tidied code
	up.  Removed segmentation fault when value is 'nil'.
	* objc/objc-api.h (_objc_unexpected_exception): Mark as
	deprecated.
	* Makefile.in (exception.lo, exception_gc.lo): Use
	-Wno-deprecated-declarations when compiling.
	(OBJC_H): Added objc-exception.h

From-SVN: r164023

5 files changed, 226 insertions, 40 deletions

diff --git a/libobjc/ChangeLog b/libobjc/ChangeLog
index e79318b..f4f8e18 100644
--- a/libobjc/ChangeLog
+++ b/libobjc/ChangeLog
@@ -1,3 +1,19 @@
+2010-09-08  Nicola Pero  <nicola.pero@meta-innovation.com>
+
+	* objc/objc-exception.h: New file.
+	* exception.c (objc_set_uncaught_exception_handler): Implemented.
+	(objc_set_exception_matcher): Implemented.
+	(objc_exception_throw): Use the uncaught exception handler if set.
+	(PERSONALITY_FUNCTION): Use the exception matcher instead of the
+	hardcoded isKindOf.
+	(isKindOf): Renamed to is_kind_of_exception_matcher.  Tidied code
+	up.  Removed segmentation fault when value is 'nil'.
+	* objc/objc-api.h (_objc_unexpected_exception): Mark as
+	deprecated.
+	* Makefile.in (exception.lo, exception_gc.lo): Use
+	-Wno-deprecated-declarations when compiling.
+	(OBJC_H): Added objc-exception.h
+
 2010-09-08  Nicola Pero  <nicola@nicola.brainstorm.co.uk>
 
 	* objc/typedstream.h: Deprecate all functions in the file.  This
diff --git a/libobjc/Makefile.in b/libobjc/Makefile.in
index 0a02e0a..d48c8dd 100644
--- a/libobjc/Makefile.in
+++ b/libobjc/Makefile.in
@@ -143,7 +143,7 @@ all: libobjc$(libsuffix).la $(OBJC_BOEHM_GC)
 
 # User-visible header files.
 
-OBJC_H = hash.h objc-list.h sarray.h objc.h objc-api.h \
+OBJC_H = hash.h objc-list.h sarray.h objc.h objc-api.h objc-exception.h \
 	 NXConstStr.h Object.h Protocol.h encoding.h typedstream.h \
 	 thr.h objc-decls.h
 
@@ -152,7 +152,7 @@ OBJC_H = hash.h objc-list.h sarray.h objc.h objc-api.h \
 OBJS =    archive.lo class.lo encoding.lo gc.lo hash.lo init.lo linking.lo \
 	  misc.lo nil_method.lo NXConstStr.lo Object.lo objects.lo \
 	  Protocol.lo sarray.lo selector.lo sendmsg.lo thr.lo \
-          exception.lo
+	  exception.lo
 
 OBJS_GC = archive_gc.lo class_gc.lo encoding_gc.lo gc_gc.lo hash_gc.lo \
 	  init_gc.lo linking_gc.lo misc_gc.lo nil_method_gc.lo \
@@ -262,13 +262,15 @@ thr_gc.lo: thr.c
 	$(LIBTOOL_COMPILE) $(CC) -c -o $@ $(ALL_CFLAGS) $(OBJC_GCFLAGS) \
 		$(INCLUDES) $<
 
+# -Wno-deprecated-declarations is to silence warnings from using 
+# _objc_unexpected_exception.
 exception.lo: exception.c
 	$(LIBTOOL_COMPILE) $(CC) -c -o $@ $(ALL_CFLAGS) \
-		-fexceptions $(INCLUDES) $<
+		-fexceptions -Wno-deprecated-declarations $(INCLUDES) $<
 
 exception_gc.lo: exception.c
 	$(LIBTOOL_COMPILE) $(CC) -c -o $@ $(ALL_CFLAGS) $(OBJC_GCFLAGS) \
-		-fexceptions $(INCLUDES) $<
+		-fexceptions -Wno-deprecated-declarations $(INCLUDES) $<
 
 doc: info dvi pdf html
 
diff --git a/libobjc/exception.c b/libobjc/exception.c
index 0ac0b66..210beae 100644
--- a/libobjc/exception.c
+++ b/libobjc/exception.c
@@ -1,5 +1,5 @@
 /* The implementation of exception handling primitives for Objective-C.
-   Copyright (C) 2004, 2005, 2007, 2008, 2009 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -25,9 +25,70 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #include <stdlib.h>
 #include "config.h"
 #include "objc/objc-api.h"
+#include "objc/objc-exception.h"
 #include "unwind.h"
 #include "unwind-pe.h"
 
+/* This hook allows libraries to sepecify special actions when an
+   exception is thrown without a handler in place.  This is deprecated
+   in favour of objc_set_uncaught_exception_handler ().
+ */
+void (*_objc_unexpected_exception) (id exception); /* !T:SAFE */
+
+
+/* 'is_kind_of_exception_matcher' is our default exception matcher -
+   it determines if the object 'exception' is of class 'catch_class',
+   or of a subclass.
+*/
+static int
+is_kind_of_exception_matcher (Class catch_class, id exception)
+{
+  /* NULL catch_class is catch-all (eg, @catch (id object)).  */
+  if (catch_class == Nil)
+    return 1;
+
+  /* If exception is nil (eg, @throw nil;), then it can only be catched
+   * by a catch-all (eg, @catch (id object)).
+   */
+  if (exception != nil)
+    {
+      Class c;
+
+      for (c = exception->class_pointer; c != Nil; 
+	   c = class_get_super_class (c))
+	if (c == catch_class)
+	  return 1;
+    }
+  return 0;
+}
+
+/* The exception matcher currently in use.  */
+static objc_exception_matcher
+__objc_exception_matcher = is_kind_of_exception_matcher;
+
+objc_exception_matcher
+objc_set_exception_matcher (objc_exception_matcher new_matcher)
+{
+  objc_exception_matcher old_matcher = __objc_exception_matcher;
+  __objc_exception_matcher = new_matcher;
+  return old_matcher;
+}
+
+/* The uncaught exception handler currently in use.  */
+static objc_uncaught_exception_handler
+__objc_uncaught_exception_handler = NULL;
+
+objc_uncaught_exception_handler
+objc_set_uncaught_exception_handler (objc_uncaught_exception_handler 
+				     new_handler)
+{
+  objc_uncaught_exception_handler old_handler 
+    = __objc_uncaught_exception_handler;
+  __objc_uncaught_exception_handler = new_handler;
+  return old_handler;
+}
+
+
 
 #ifdef __ARM_EABI_UNWINDER__
 
@@ -84,11 +145,6 @@ struct lsda_header_info
   unsigned char call_site_encoding;
 };
 
-/* This hook allows libraries to sepecify special actions when an
-   exception is thrown without a handler in place.
- */
-void (*_objc_unexpected_exception) (id exception); /* !T:SAFE */
-
 static const unsigned char *
 parse_lsda_header (struct _Unwind_Context *context, const unsigned char *p,
 		   struct lsda_header_info *info)
@@ -160,25 +216,6 @@ get_ttype_entry (struct lsda_header_info *info, _Unwind_Word i)
 
 #endif
 
-/* Like unto the method of the same name on Object, but takes an id.  */
-/* ??? Does this bork the meta-type system?  Can/should we look up an
-   isKindOf method on the id?  */
-
-static int
-isKindOf (id value, Class target)
-{
-  Class c;
-
-  /* NULL target is catch-all.  */
-  if (target == 0)
-    return 1;
-
-  for (c = value->class_pointer; c; c = class_get_super_class (c))
-    if (c == target)
-      return 1;
-  return 0;
-}
-
 /* Using a different personality function name causes link failures
    when trying to mix code using different exception handling models.  */
 #ifdef SJLJ_EXCEPTIONS
@@ -406,7 +443,7 @@ PERSONALITY_FUNCTION (int version,
 
 	      Class catch_type = get_ttype_entry (&info, ar_filter);
 
-	      if (isKindOf (xh->value, catch_type))
+	      if ((*__objc_exception_matcher) (catch_type, xh->value))
 		{
 		  handler_switch_value = ar_filter;
 		  saw_handler = 1;
@@ -473,14 +510,14 @@ __objc_exception_cleanup (_Unwind_Reason_Code code __attribute__((unused)),
 }
 
 void
-objc_exception_throw (id value)
+objc_exception_throw (id exception)
 {
   struct ObjcException *header = calloc (1, sizeof (*header));
-  
+
   memcpy (&header->base.exception_class, &__objc_exception_class,
 	  sizeof (__objc_exception_class));
   header->base.exception_cleanup = __objc_exception_cleanup;
-  header->value = value;
+  header->value = exception;
 
 #ifdef SJLJ_EXCEPTIONS
   _Unwind_SjLj_RaiseException (&header->base);
@@ -488,10 +525,22 @@ objc_exception_throw (id value)
   _Unwind_RaiseException (&header->base);
 #endif
 
-  /* Some sort of unwinding error.  */
+  /* No exception handler was installed.  Call the uncaught exception
+     handler if any is defined.
+   */
+  if (__objc_uncaught_exception_handler != 0)
+    {
+      (*__objc_uncaught_exception_handler) (exception);
+    }
+
+  /* As a last resort support the old, deprecated way of setting an
+     uncaught exception handler.
+  */
   if (_objc_unexpected_exception != 0)
     {
-      (*_objc_unexpected_exception) (value);
+      (*_objc_unexpected_exception) (exception);
     }
+
   abort ();
 }
+
diff --git a/libobjc/objc/objc-api.h b/libobjc/objc/objc-api.h
index 30984b1..8a634a4 100644
--- a/libobjc/objc/objc-api.h
+++ b/libobjc/objc/objc-api.h
@@ -431,12 +431,14 @@ objc_EXPORT IMP (*__objc_msg_forward)(SEL);
 objc_EXPORT IMP (*__objc_msg_forward2)(id, SEL);
 
 /*
-** Hook for uncaught exceptions.  This hook is called when an exception
-** is thrown and no valid exception handler is in place.  The function
-** is expected never to return.  If the function returns the result is
-** currently undefined.
+** Hook for uncaught exceptions.  This hook is called when an
+** exception is thrown and no valid exception handler is in place.
+** The function is expected never to return.  If the function returns
+** the result is currently undefined.  This is deprecated.  Please use
+** objc_set_uncaught_exception_handler() from objc/objc-exception.h
+** instead.
 */
-objc_EXPORT void (*_objc_unexpected_exception)(id);
+objc_EXPORT void (*_objc_unexpected_exception)(id) __attribute__ ((deprecated));
 
 
 Method_t class_get_class_method(MetaClass _class, SEL aSel);
diff --git a/libobjc/objc/objc-exception.h b/libobjc/objc/objc-exception.h
new file mode 100644
index 0000000..e12ff3a
--- /dev/null
+++ b/libobjc/objc/objc-exception.h
@@ -0,0 +1,117 @@
+/* GNU Objective C Runtime native exceptions
+   Copyright (C) 2010 Free Software Foundation, Inc.
+   Contributed by Nicola Pero <nicola.pero@meta-innovation.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef __objc_exception_INCLUDE_GNU
+#define __objc_exception_INCLUDE_GNU
+
+#include <objc/objc.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* 'objc_exception_throw' throws the exception 'exception', which is
+   an exception object.
+
+   Calls to 'objc_exception_throw' are automatically generated by the
+   compiler: an Objective-C "@throw exception;" statement gets
+   compiled into the equivalent of "objc_exception_throw
+   (exception);".
+
+   'objc_exception_throw' searches for a @catch() that can catch the
+   exception.  By default, @catch (MyClass object) will catch all
+   exception objects that are of class MyClass or of a subclass of
+   MyClass; if the exception object is 'nil', then the exception can
+   only be caught with a catch-all exception handler where no
+   exception class is specified (such as @catch(id object)).  This
+   behaviour can be customized by setting an 'objc_exception_matcher'
+   function (using objc_set_exception_matcher(), see below); if one is
+   set, it is used instead of the default one.
+
+   If the exception is uncaught (there is no @catch() to catch it),
+   the program aborts.  It is possible to customize this behaviour by
+   setting an 'objc_uncaught_exception_handler' function (using
+   objc_set_uncaught_exception_handler(), see below); if one is set,
+   it is executed before abort() is called.  An uncaught exception
+   handler is expected to never return.
+ */
+void objc_exception_throw (id exception);
+
+/* PS: the Apple runtime seems to also have objc_exception_rethrow(),
+   objc_begin_catch() and objc_end_catch().  Currently the GNU runtime
+   does not use them.
+*/
+
+/* The following functions allow customizing to a certain extent the
+   exception handling.  They are not thread safe and should be called
+   during the program initialization before threads are started.  They
+   are mostly reserved for "Foundation" libraries; in the case of
+   GNUstep, gnustep-base may be using these functions to improve the
+   standard exception handling.  You probably shouldn't use these
+   functions unless you are writing your own Foundation library.
+*/
+
+/* PS: objc_set_exception_preprocessor() (available on the Apple
+   runtime) is not supported on the GNU runtime.  */
+
+/* An 'objc_exception_matcher' function is used to match an exception
+   to a @catch clause.  'catch_class' is the class of objects caught
+   by the @catch clause (for example, in "@catch (Object *o)", the
+   catch_class is Object).  It should return 1 if the exception should
+   be caught by a @catch with a catch_class argument, and 0 if
+   not.  */
+typedef int (*objc_exception_matcher)(Class catch_class, id exception);
+
+/* Sets a new exception matcher function, and returns the previous
+   exception matcher function.  This function is not safe to call in a
+   multi-threaded environment because other threads may be trying to
+   invoke the exception matcher while you change it!  */
+objc_exception_matcher
+objc_set_exception_matcher (objc_exception_matcher new_matcher);
+
+
+/* An 'objc_uncaught_exception_handler' function is a function that
+   handles uncaught exceptions.  It should never return.  */
+typedef void (*objc_uncaught_exception_handler)(id exception);
+
+/* Sets a new uncaught exception handler function, and returns the
+   previous exception handler function.  This function is not safe to
+   call in a multi-threaded environment because other threads may be
+   trying to invoke the uncaught exception handler while you change
+   it.
+*/
+objc_uncaught_exception_handler
+objc_set_uncaught_exception_handler (objc_uncaught_exception_handler new_handler);
+
+
+/* For compatibility with the Apple runtime.  */
+#define objc_setExceptionMatcher objc_set_exception_matcher
+#define objc_setUncaughtExceptionHandler objc_set_uncaught_exception_handler
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* not __objc_exception_INCLUDE_GNU */