[rfa/threads] Convert thread event descriptors to code addrs

[Andrew Cagney <ac131313 at redhat dot com>]

Hello,

For PPC64 every function has two minimal symbols vis:

.__nptl_create_event: the start address
__nptl_create_event: the descriptor

This patch modifies ps_pglobal_lookup so that it always returns the 
function's start address.  Doing this ensures that libthread_db and 
GDB's thread code are "on the same page" when it comes to the true 
address of the thread-create and thread-death breakpoints.

The alternative would be to modify libthread_db so that it knew that 
PPC64 symbol were special but I suspect that it doesn't want to know 
about such underlying details.

ok for mainline?
Andrew

2003-11-25  Andrew Cagney  <cagney@redhat.com>

	* proc-service.c (ps_pglobal_lookup): Convert function descriptors
	into code addresses using gdbarch_convert_from_func_ptr_addr.

Index: ./gdb/proc-service.c
===================================================================
RCS file: /cvs/src/src/gdb/proc-service.c,v
retrieving revision 1.7
diff -u -r1.7 proc-service.c
--- ./gdb/proc-service.c	24 Feb 2002 22:31:19 -0000	1.7
+++ ./gdb/proc-service.c	25 Nov 2003 20:59:49 -0000
@@ -181,7 +181,13 @@
   if (ms == NULL)
     return PS_NOSYM;
 
-  *sym_addr = SYMBOL_VALUE_ADDRESS (ms);
+  /* Get the addres, make certain that any descriptors are converted
+     into corresponding code addresses.  (For PPC64, the symbol
+     "__nptl_create_event" points at a function descriptor while this
+     code needs the corresponding function's start address.)  */
+  *sym_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
+						  SYMBOL_VALUE_ADDRESS (ms),
+						  &current_target);
   return PS_OK;
 }