IA-64 unwind handler cleanup

[Jim Wilson <wilson at cygnus dot com>]

I noticed this while fixing a problem with gas's handling of the EHANDLER and
UHANDLER bits.  Gcc wasn't using the bits to identify whether a personality
routine was present.  This doesn't fix any known bugs, but makes it more
likely that the IA-64 unwinding code will work for non-g++ compiled code.

2000-08-23  Jim Wilson  <wilson@cygnus.com>

	* frame.h (IA64_UNW_EHANDLER, IA64_UNW_UHANDLER): New.
	* config/ia64/frame-ia64.c (__get_personality): Return zero if neither
	EHANDLER nor UHANDLER bit is set.
	(__get_except_table): Likewise.

Index: frame.h
===================================================================
RCS file: /cvs/cvsfiles/devo/gcc/frame.h,v
retrieving revision 1.16.10.1
diff -p -r1.16.10.1 frame.h
*** frame.h	2000/08/08 09:09:56	1.16.10.1
--- frame.h	2000/08/23 20:41:56
*************** typedef struct unwind_info_ptr 
*** 267,272 ****
--- 267,276 ----
  #define IA64_UNW_HDR_FLAGS(x)	(((x) >> 32) & 0xffffUL)
  #define IA64_UNW_HDR_VERSION(x)	(((x) >> 48) & 0xffffUL)
  
+ /* Header flag bits, after extraction by IA64_UNW_HDR_FLAGS.  */
+ #define IA64_UNW_EHANDLER	0x1
+ #define IA64_UNW_UHANDLER	0x2
+ 
  extern unwind_info_ptr *__build_ia64_frame_state (unsigned char *, 
  						  ia64_frame_state *,
  						  void *, void *,
Index: config/ia64/frame-ia64.c
===================================================================
RCS file: /cvs/cvsfiles/devo/gcc/config/ia64/frame-ia64.c,v
retrieving revision 1.4.10.1
diff -p -r1.4.10.1 frame-ia64.c
*** frame-ia64.c	2000/08/08 09:09:57	1.4.10.1
--- frame-ia64.c	2000/08/23 20:41:56
*************** __build_ia64_frame_state (pc, frame, bsp
*** 1376,1402 ****
    return unw_info_ptr;
  }
  
! /* Given an unwind info pointer, return the personailty routine.  */
  void *
  __get_personality (ptr)
       unwind_info_ptr *ptr;
  {
    void **p;
    p = (void **) (ptr->unwind_descriptors
  		 + IA64_UNW_HDR_LENGTH (ptr->header) * 8);
    return *p;
  }
  
  void *
  __get_except_table (ptr)
       unwind_info_ptr *ptr;
  {
!   void **p, *table;
!   p = (void **) (ptr->unwind_descriptors
! 		 + IA64_UNW_HDR_LENGTH (ptr->header) * 8);
!   /* If there is no personality, there is no handler data.  */
!   if (*p == 0)
      return 0;
    table = (void *) (ptr->unwind_descriptors
  		    + IA64_UNW_HDR_LENGTH (ptr->header) * 8 + 8);
    return table;
--- 1376,1413 ----
    return unw_info_ptr;
  }
  
! /* Given an unwind info pointer, return the personality routine.  */
  void *
  __get_personality (ptr)
       unwind_info_ptr *ptr;
  {
    void **p;
+ 
+   /* There is a personality routine only if one of the EHANDLER or UHANDLER
+      bits is set.  */
+   if (! (IA64_UNW_HDR_FLAGS (ptr->header)
+ 	 & (IA64_UNW_EHANDLER|IA64_UNW_UHANDLER)))
+     return 0;
+ 
    p = (void **) (ptr->unwind_descriptors
  		 + IA64_UNW_HDR_LENGTH (ptr->header) * 8);
    return *p;
  }
  
+ /* Given an unwind info pointer, return the exception table.  */
  void *
  __get_except_table (ptr)
       unwind_info_ptr *ptr;
  {
!   void *table;
! 
!   /* If there is no personality, there is no handler data.
!      There is a personality routine only if one of the EHANDLER or UHANDLER
!      bits is set.  */
!   if (! (IA64_UNW_HDR_FLAGS (ptr->header)
! 	 & (IA64_UNW_EHANDLER|IA64_UNW_UHANDLER)))
      return 0;
+ 
    table = (void *) (ptr->unwind_descriptors
  		    + IA64_UNW_HDR_LENGTH (ptr->header) * 8 + 8);
    return table;