[patch] Fix shared library handling in solib-pa64.c (take 2)

["John David Anglin" <dave@hiauly1.hia.nrc.ca>]

> Does this really do what you want it to?
> 
> Looking at that HP man page, it looks like dlmodinfo will use "its own
> data structures" - i.e. GDB's load map, not the debugged program's.

Here's take 2.  This one actually works.  This shows the result
for a simple program.

...
This GDB was configured as "hppa64-hp-hpux11.00"...
(gdb) info shared
No shared libraries loaded at this time.
(gdb) break main
Breakpoint 1 at 0x40000000000029c8: file main.c, line 4.
(gdb) r
Starting program: /home/gnu/gdb/objdir64/main 
warning: Loadable segment ".tbss" outside of ELF segments
warning: Loadable segment ".tbss" outside of ELF segments

Breakpoint 1, main () at main.c:4
4	  return 0;
(gdb) info shared
From                To                  Syms Read   Shared Object Library
0xc00000000000ac80  0xc0000000000419b4  Yes         /usr/lib/pa20_64/dld.sl
0x800003ffeff23538  0x800003ffeffe67f8  Yes         /lib/pa20_64/libc.2
0x800003ffefec7150  0x800003ffefec8578  Yes         /usr/lib/pa20_64/libdl.1
0x800003ffefec2574  0x800003ffefec2574  Yes         /opt/graphics/OpenGL/lib/pa20_64/libogltls.sl

One thing that I have noticed is that the shared libraries are always
forced private which makes them writeable.  I recently had a program
which dropped core when the library code was shared but not when they
were private.

On hpux 11, the chatr "+dbg" can be used to make libraries private or
shareable.  Possibly, it's not a great idea to always force private
libraries.  Detection of this is broken for the som target.  The
information is now in the shared library header and not __dld_flags.
On hpux 10, I guess we are stuck with forcing private libraries.

Ok?

Dave
-- 
J. David Anglin                                  dave.anglin@nrc-cnrc.gc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6602)

2008-08-06  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>

	* solib-pa64.c (read_dld_descriptor): Return zero if load map is not
	setup.

Index: solib-pa64.c
===================================================================
RCS file: /cvs/src/src/gdb/solib-pa64.c,v
retrieving revision 1.10
diff -u -3 -p -r1.10 solib-pa64.c
--- solib-pa64.c	1 Jan 2008 22:53:13 -0000	1.10
+++ solib-pa64.c	6 Aug 2008 17:19:39 -0000
@@ -125,8 +125,8 @@ pa64_target_read_memory (void *buffer, C
 
    This must happen after dld starts running, so we can't do it in
    read_dynamic_info.  Record the fact that we have loaded the
-   descriptor.  If the library is archive bound, then return zero, else
-   return nonzero.  */
+   descriptor.  If the library is archive bound or the load map
+   hasn't been setup, then return zero; else return nonzero.  */
 
 static int
 read_dld_descriptor (void)
@@ -161,6 +161,9 @@ read_dld_descriptor (void)
       error (_("Error while reading in load map pointer."));
     }
 
+  if (!dld_cache.load_map)
+    return 0;
+
   /* Read in the dld load module descriptor */
   if (dlgetmodinfo (-1, 
 		    &dld_cache.dld_desc,