[PATCH] Remove zero PC check from blockframe.c:inside_main_func()

[Mark Kettenis <kettenis@chello.nl>]

It really makes no sense to check for a zero PC here.  This function
is only colled from frame.c:get_prev_frame(), and there we already
deal with PC being zero.

The whole concept of using a zero PC as a marker for the end of the
frame chain is somewhat flawed.  It prevents us from providing a
meaningful backtrace when the program has called a null function
pointer; see backtrace/1476.  At the very least we will have to treat
a zero PC in the innermost differently.  Classifying the a zero PC as
being inside the "main" function doesn't help.  Therefore this patch
removes the first obstackle in fixing that PR.

Objections.  Otherwise I'll commit this within a few days.

Mark


Index: ChangeLog
from  Mark Kettenis  <kettenis@gnu.org>
 
	* blockframe.c (inside_main_func): Don't treat a zero PC specially.
	Needed to fix PR backtrace/1476.

Index: blockframe.c
===================================================================
RCS file: /cvs/src/src/gdb/blockframe.c,v
retrieving revision 1.83
diff -u -p -r1.83 blockframe.c
--- blockframe.c 13 Dec 2003 13:16:52 -0000 1.83
+++ blockframe.c 13 Dec 2003 14:50:01 -0000
@@ -73,17 +73,12 @@ deprecated_inside_entry_file (CORE_ADDR 
 }
 
 /* Test whether PC is in the range of addresses that corresponds to
-   the "main" function.
-
-   A PC of zero is always considered to be the bottom of the stack.  */
+   the "main" function.  */
 
 int
 inside_main_func (CORE_ADDR pc)
 {
   struct minimal_symbol *msymbol;
-
-  if (pc == 0)
-    return 1;
 
   if (symfile_objfile == 0)
     return 0;