[PATCH] use gdbarch_addr_bits_remove for entry point address

[Yao Qi <yao@codesourcery.com>]

Hi,
This patch attempts to clear the lsb of the entry address, which might
be set by compiler for thumb code.

This patch does something similar to this one,

  RFC: Handle ISA bits for the entry point
  http://sourceware.org/ml/gdb-patches/2009-07/msg00682.html

Regression tested on arm-none-linux-gnueabi.  Is it OK?

gdb:

2012-11-20  Daniel Jacobowitz  <dan@codesourcery.com>
	    Kazu Hirata  <kazu@codesourcery.com>
	    Yao Qi  <yao@codesourcery.com>

	* objfiles.c (init_entry_point_info): Use gdbarch_addr_bits_remove.
	* solib-svr4.c (exec_entry_point): Likewise.
	* symfile.c (generic_load): Call gdbarch_addr_bits_remove on
	the entry address.
---
 gdb/objfiles.c   |    5 +++++
 gdb/solib-svr4.c |    5 ++++-
 gdb/symfile.c    |    1 +
 3 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/gdb/objfiles.c b/gdb/objfiles.c
index a1db8c6..3374c68 100644
--- a/gdb/objfiles.c
+++ b/gdb/objfiles.c
@@ -353,6 +353,11 @@ init_entry_point_info (struct objfile *objfile)
       /* Examination of non-executable.o files.  Short-circuit this stuff.  */
       objfile->ei.entry_point_p = 0;
     }
+
+  if (objfile->ei.entry_point_p)
+    objfile->ei.entry_point
+      = gdbarch_addr_bits_remove (objfile->gdbarch,
+				  objfile->ei.entry_point);
 }
 
 /* If there is a valid and known entry point, function fills *ENTRY_P with it
diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c
index 37cc654..02e45a3 100644
--- a/gdb/solib-svr4.c
+++ b/gdb/solib-svr4.c
@@ -1388,6 +1388,8 @@ svr4_in_dynsym_resolve_code (CORE_ADDR pc)
 static CORE_ADDR
 exec_entry_point (struct bfd *abfd, struct target_ops *targ)
 {
+  CORE_ADDR addr;
+
   /* KevinB wrote ... for most targets, the address returned by
      bfd_get_start_address() is the entry point for the start
      function.  But, for some targets, bfd_get_start_address() returns
@@ -1396,9 +1398,10 @@ exec_entry_point (struct bfd *abfd, struct target_ops *targ)
      gdbarch_convert_from_func_ptr_addr().  The method
      gdbarch_convert_from_func_ptr_addr() is the merely the identify
      function for targets which don't use function descriptors.  */
-  return gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
+  addr = gdbarch_convert_from_func_ptr_addr (target_gdbarch (),
 					     bfd_get_start_address (abfd),
 					     targ);
+  return gdbarch_addr_bits_remove (target_gdbarch (), addr);
 }
 
 /* Helper function for gdb_bfd_lookup_symbol.  */
diff --git a/gdb/symfile.c b/gdb/symfile.c
index 55af541..70f631f 100644
--- a/gdb/symfile.c
+++ b/gdb/symfile.c
@@ -2132,6 +2132,7 @@ generic_load (char *args, int from_tty)
   gettimeofday (&end_time, NULL);
 
   entry = bfd_get_start_address (loadfile_bfd);
+  entry = gdbarch_addr_bits_remove (target_gdbarch (), entry);
   ui_out_text (uiout, "Start address ");
   ui_out_field_fmt (uiout, "address", "%s", paddress (target_gdbarch (), entry));
   ui_out_text (uiout, ", load size ");
-- 
1.7.7.6