[RFA]: Fix bug gdb/321

[Corinna Vinschen <vinschen@redhat.com>]

Hi,

the following patch seems to fix the bug described in gdb/321:

http://sources.redhat.com/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gdb&pr=321

Basically the problem is that gdb's backtrace reports the wrong calling
function if a function ends in a call to abort() (or another noreturn func)
under some conditions.  The bug report suggests to use a by one decremented
pc when evaluating the function.  The following patch does exactly this by
using the return value of frame_address_in_block() instead of frame->pc in
calls which evaluate symbols.

Corinna

ChangeLog:

        * stack.c (print_frame): Use result of frame_address_in_block()
        instead of fi->pc when evaluating symbols.
        (backtrace_command_1): Ditto.

Index: stack.c
===================================================================
RCS file: /cvs/src/src/gdb/stack.c,v
retrieving revision 1.39
diff -u -p -r1.39 stack.c
--- stack.c	10 Jun 2002 23:25:50 -0000	1.39
+++ stack.c	11 Jul 2002 18:42:47 -0000
@@ -461,7 +461,7 @@ print_frame (struct frame_info *fi, 
   stb = ui_out_stream_new (uiout);
   old_chain = make_cleanup_ui_out_stream_delete (stb);
 
-  func = find_pc_function (fi->pc);
+  func = find_pc_function (frame_address_in_block (fi));
   if (func)
     {
       /* In certain pathological cases, the symtabs give the wrong
@@ -480,7 +480,7 @@ print_frame (struct frame_info *fi, 
          ever changed many parts of GDB will need to be changed (and we'll
          create a find_pc_minimal_function or some such).  */
 
-      struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (fi->pc);
+      struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (frame_address_in_block (fi));
       if (msymbol != NULL
 	  && (SYMBOL_VALUE_ADDRESS (msymbol)
 	      > BLOCK_START (SYMBOL_BLOCK_VALUE (func))))
@@ -528,7 +528,7 @@ print_frame (struct frame_info *fi, 
     }
   else
     {
-      struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (fi->pc);
+      struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (frame_address_in_block (fi));
       if (msymbol != NULL)
 	{
 	  funname = SYMBOL_NAME (msymbol);
@@ -1111,7 +1111,7 @@ backtrace_command_1 (char *count_exp, in
 	   fi = get_prev_frame (fi))
 	{
 	  QUIT;
-	  ps = find_pc_psymtab (fi->pc);
+	  ps = find_pc_psymtab (frame_address_in_block (fi));
 	  if (ps)
 	    PSYMTAB_TO_SYMTAB (ps);	/* Force syms to come in */
 	}

-- 
Corinna Vinschen
Cygwin Developer
Red Hat, Inc.
mailto:vinschen@redhat.com