* top.c (SIGJMP_BUF, SIGSETJMP, SIGLONGJMP): Update comments.

	(error_return, quit_return): Merge into catch_return pointer.
	(return_to_top_level): Update comment.  Longjmp to *catch_errors,
	and communicate reason to catch_errors via setjmp return value.
	(catch_errors): Always catch both quit and error, and if a catch
	wasn't requested by caller, throw it to the next catch_error.
	Replace dual longjmp buffer memcpy with single pointer change.
	Add FIXME for possibly adding new interface to tell caller what
	event was caught.  Add extensive comments.
	* defs.h (enum return_reason): Reserve 0 for use as initial
	setjmp() return value.
	(RETURN_MASK): New public macro to generate RETURN_MASK_* from
	enum return_reason.
	(RETURN_MASK_QUIT, RETURN_MASK_ERROR): Define using RETURN_MASK.

1 files changed, 8 insertions, 5 deletions

diff --git a/gdb/defs.h b/gdb/defs.h
index fa9f540..c4756f1 100644
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -801,21 +801,24 @@ extern NORETURN void internal_error (char *, ...) ATTR_NORETURN;
 
 extern NORETURN void nomem (long) ATTR_NORETURN;
 
-/* Reasons for calling return_to_top_level.  */
+/* Reasons for calling return_to_top_level.  Note: enum value 0 is
+   reserved for internal use as the return value from an initial
+   setjmp().  */
 
 enum return_reason
   {
     /* User interrupt.  */
-    RETURN_QUIT,
+    RETURN_QUIT = 1,
     /* Any other error.  */
     RETURN_ERROR
   };
 
 #define	ALL_CLEANUPS	((struct cleanup *)0)
 
-#define RETURN_MASK_QUIT (1 << (int)RETURN_QUIT)
-#define RETURN_MASK_ERROR (1 << (int)RETURN_ERROR)
-#define RETURN_MASK_ALL (RETURN_MASK_QUIT | RETURN_MASK_ERROR)
+#define RETURN_MASK(reason)	(1 << (int)(reason))
+#define RETURN_MASK_QUIT	RETURN_MASK (RETURN_QUIT)
+#define RETURN_MASK_ERROR	RETURN_MASK (RETURN_ERROR)
+#define RETURN_MASK_ALL		(RETURN_MASK_QUIT | RETURN_MASK_ERROR)
 typedef int return_mask;
 
 extern NORETURN void return_to_top_level (enum return_reason) ATTR_NORETURN;