remove some sym_probe_fns methods

While looking into the probe API, it seemed to me that there were a
number of methods in sym_probe_fns that were not needed.  This patch
removes them.

Specifically, it seems to me that sym_probe_fns ought to be concerned
with the API for constructing the probes.  Any method relating to some
aspect of an individual probe can be handled via the probe's own
vtable.  That is, the double indirection here doesn't seem useful --
it certainly isn't in fact used, but also I couldn't think of a
potential use.

2013-12-06  Tom Tromey  <tromey@redhat.com>

	* break-catch-throw.c (fetch_probe_arguments): Use
	get_probe_argument_count and evaluate_probe_argument.
	* elfread.c (elf_get_probe_argument_count)
	(elf_can_evaluate_probe_arguments, elf_evaluate_probe_argument)
	(elf_compile_to_ax): Remove.
	(elf_probe_fns): Update.
	* probe.c (get_probe_argument_count, can_evaluate_probe_arguments)
	(evaluate_probe_argument): Call method on probe, not via sym
	functions.
	* stap-probe.c (compute_probe_arg): Use get_probe_argument_count,
	evaluate_probe_argument.
	(compile_probe_arg): Use get_probe_argument_count.  Call method on
	probe, not via sym functions.
	* symfile-debug.c (debug_sym_get_probe_argument_count)
	(debug_can_evaluate_probe_arguments)
	(debug_sym_evaluate_probe_argument, debug_sym_compile_to_ax):
	Remove.
	(debug_sym_probe_fns): Remove.
	* symfile.h (struct sym_probe_fns) <sym_get_probe_argument_count,
	can_evaluate_probe_arguments, sym_evaluate_probe_argument,
	sym_compile_to_ax>: Remove fields.
	* gdb.base/break.exp: Fix setting of $baz.
make symtab::filename const

This makes symtab::filename const and removes a newly unnecessary
cast.

2013-12-06  Tom Tromey  <tromey@redhat.com>

	* symfile.c (allocate_symtab): Remove cast.
	* symtab.h (struct symtab) <filename>: Now const.
make symtab::dirname const

This makes symtab::dirname const and updates one spot to avoid an
intermediate constless result.

2013-12-06  Tom Tromey  <tromey@redhat.com>

	* buildsym.c (end_symtab_from_static_block): Use obstack_copy0.
	* symtab.h (struct symtab) <dirname>: Now const.
put the psymtab filename in the filename bcache

This puts the psymtab filename in the filename bcache.
This saves a small amount of memory.

2013-12-06  Tom Tromey  <tromey@redhat.com>

	* psymtab.c (allocate_psymtab): Put the filename in the filename
	bcache.
fix a couple of FIXMEs

This fixes a couple of old "32x64" FIXME comments by using paddress
with current_gdbarch rather than hex_string and a cast to long.

2013-12-06  Tom Tromey  <tromey@redhat.com>

	* cli/cli-cmds.c (edit_command): Use paddress, not hex_string.
	(list_command): Likewise.
pack partial_symtab for space

This improves the packing of struct partial_symtab.  I noticed with
pahole that were were a couple of holes.  This consolidates the holes
without, I think, affecting readability -- it just moves the "user"
field a bit earlier in the struct.  This change saves a small amount
of memory.

2013-12-06  Tom Tromey  <tromey@redhat.com>

	* psympriv.h (struct partial_symtab) <user>: Move earlier.
remove unnecessary declaration

This removes an unnecessary declaration from minsyms.c.

2013-12-06  Tom Tromey  <tromey@redhat.com>

	* minsyms.c (get_symbol_leading_char): Remove unnecessary
	declaration.
remove objfile_to_front

I happened to notice that nothing uses objfile_to_front.
This patch removes it.

2013-12-06  Tom Tromey  <tromey@redhat.com>

	* objfiles.h (objfile_to_front): Remove.
	* objfiles.c (objfile_to_front): Remove.
update free_objfile comment

The introductory comment to free_objfile is obsolete.
This patch fixes it by removing all the obsolete bits.

2013-12-06  Tom Tromey  <tromey@redhat.com>

	* objfiles.c (free_objfile): Update comment.
New OPTIMIZED_OUT_ERROR error code.

In order to catch <optimized out> errors like we catch <unavailable>
errors, this adds a new OPTIMIZED_OUT_ERROR error code, and throws it
in various places.

gdb/ChangeLog
2013-12-06  Andrew Burgess  <aburgess@broadcom.com>
	    Pedro Alves  <palves@redhat.com>

	* exceptions.h (errors): Add OPTIMIZED_OUT_ERROR.
	* dwarf2loc.c (write_pieced_value): Throw OPTIMIZED_OUT_ERROR.
	* frame.c (frame_unwind_register): Throw OPTIMIZED_OUT_ERROR.
	* spu-tdep.c (spu_software_single_step): Throw
	OPTIMIZED_OUT_ERROR.
	* valops.c (value_assign): Throw OPTIMIZED_OUT_ERROR.
Fix "info frame" in the outermost frame.

Doing "info frame" in the outermost frame, when that was indicated by
the next frame saying the unwound PC is undefined/not saved, results
in error and incomplete output:

 (gdb) bt
 #0  thread_function0 (arg=0x0) at threads.c:63
 #1  0x00000034cf407d14 in start_thread (arg=0x7ffff7fcb700) at pthread_create.c:309
 #2  0x000000323d4f168d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115

 (gdb) frame 2
 #2  0x000000323d4f168d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:115
 115             call    *%rax

 (gdb) info frame
 Stack level 2, frame at 0x0:
  rip = 0x323d4f168d in clone (../sysdeps/unix/sysv/linux/x86_64/clone.S:115); saved rip Register 16 was not saved
 (gdb)

Not saved register values are treated as optimized out values
internally throughout.  stack.c:frame_info is handing unvailable
values, but not optimized out ones.  The patch deletes the
frame_unwind_caller_pc_if_available wrapper function and instead lets
errors propagate to frame_info (it's only user).

As frame_unwind_pc now needs to be able to handle and cache two
different error scenarios, the prev_pc.p variable is replaced with an
enumeration.

(FWIW, I looked into making gdbarch_unwind_pc or a variant return
struct value's instead, but it results in lots of boxing and unboxing
for no real gain -- e.g., the mips and arm implementations need to do
computation on the unboxed PC value.  Might as well throw an error on
first attempt to get at invalid contents.)

After the patch, we get:

 (gdb) info frame
 Stack level 2, frame at 0x0:
  rip = 0x323d4f168d in clone (../sysdeps/unix/sysv/linux/x86_64/clone.S:115); saved rip = <not saved>
  Outermost frame: outermost
  caller of frame at 0x7ffff7fcafc0
  source language asm.
  Arglist at 0x7ffff7fcafb8, args:
  Locals at 0x7ffff7fcafb8, Previous frame's sp is 0x7ffff7fcafc8
 (gdb)

A new test is added.  It's based off dw2-reg-undefined.exp, and tweaked to
mark the return address (rip) of "stop_frame" as undefined.

Tested on x86_64 Fedora 17.

gdb/
2013-12-06  Pedro Alves  <palves@redhat.com>

	* frame.c (enum cached_copy_status): New enum.
	(struct frame_info) <prev_pc.p>: Change type to enum
	cached_copy_status.
	(fprint_frame): Handle not saved and unavailable prev_pc values.
	(frame_unwind_pc_if_available): Delete and merge contents into ...
	(frame_unwind_pc): ... here.  Handle OPTIMIZED_OUT_ERROR.  Adjust
	to use enum cached_copy_status.
	(frame_unwind_caller_pc_if_available): Delete.
	(create_new_frame): Adjust.
	* frame.h (frame_unwind_caller_pc_if_available): Delete
	declaration.
	* stack.c (frame_info): Use frame_unwind_caller_pc instead of
	frame_unwind_caller_pc_if_available, and handle
	NOT_AVAILABLE_ERROR and OPTIMIZED_OUT_ERROR errors.
	* valprint.c (val_print_optimized_out): Use val_print_not_saved.
	(val_print_not_saved): New function.
	* valprint.h (val_print_not_saved): Declare.

gdb/testsuite/
2013-12-06  Pedro Alves  <palves@redhat.com>

	* gdb.dwarf2/dw2-undefined-ret-addr.S: New file.
	* gdb.dwarf2/dw2-undefined-ret-addr.c: New file.
	* gdb.dwarf2/dw2-undefined-ret-addr.exp: New file.