constify struct block in some places

This makes some spots in gdb, particularly general_symbol_info, use a
"const struct block", then fixes the fallout.

The justification is that, ordinarily, blocks ought to be readonly.
Note though that we can't add "const" in the blockvector due to block
relocation.  This can be done once blocks are made independent of the
program space.

2014-06-18  Tom Tromey  <tromey@redhat.com>

	* varobj.c (varobj_create): Update.
	* valops.c (value_of_this): Update.
	* tracepoint.c (add_local_symbols, scope_info): Update.
	* symtab.h (struct general_symbol_info) <block>: Now const.
	* symtab.c (skip_prologue_sal)
	(default_make_symbol_completion_list_break_on)
	(skip_prologue_using_sal): Update.
	* stack.h (iterate_over_block_locals)
	(iterate_over_block_local_vars): Update.
	* stack.c (print_frame_args): Update.
	(iterate_over_block_locals, iterate_over_block_local_vars): Make
	parameter const.
	(get_selected_block): Make return type const.
	* python/py-frame.c (frapy_block): Update.
	* python/py-block.c (gdbpy_block_for_pc): Update.
	* p-exp.y (%union) <bval>: Now const.
	* mi/mi-cmd-stack.c (list_args_or_locals): Update.
	* mdebugread.c (mylookup_symbol, parse_procedure): Update.
	* m2-exp.y (%union) <bval>: Now const.
	* linespec.c (get_current_search_block): Make return type const.
	(create_sals_line_offset, find_label_symbols): Update.
	* inline-frame.c (inline_frame_sniffer, skip_inline_frames):
	Update.
	(block_starting_point_at): Make "block" const.
	* infrun.c (insert_exception_resume_breakpoint): Make "b" const.
	(check_exception_resume): Update.
	* guile/scm-frame.c (gdbscm_frame_block): Update.
	* guile/scm-block.c (gdbscm_lookup_block): Update.
	* frame.h (get_frame_block): Update.
	(get_selected_block): Make return type const.
	* frame.c (frame_id_inner): Update.
	* f-valprint.c (info_common_command_for_block)
	(info_common_command): Update.
	* dwarf2loc.c (dwarf2_find_location_expression)
	(dwarf_expr_frame_base, dwarf2_compile_expr_to_ax)
	(locexpr_describe_location_piece): Update.
	* c-exp.y (%union) <bval>: Now const.
	* breakpoint.c (resolve_sal_pc): Update.
	* blockframe.c (get_frame_block):Make return type const.
	(get_pc_function_start, get_frame_function, find_pc_sect_function)
	(block_innermost_frame): Update.
	* block.h (blockvector_for_pc, blockvector_for_pc_sect)
	(block_for_pc, block_for_pc_sect): Update.
	* block.c (blockvector_for_pc_sect, blockvector_for_pc): Make
	'pblock' const.
	(block_for_pc_sect, block_for_pc): Make return type const.
	* ax-gdb.c (gen_expr): Update.
	* alpha-mdebug-tdep.c (find_proc_desc): Update.
	* ada-lang.c (ada_read_renaming_var_value): Make 'block' const.
	(ada_make_symbol_completion_list, ada_add_exceptions_from_frame)
	(ada_read_var_value): Update.
	* ada-exp.y (struct name_info) <block>: Now const.
	(%union): Likewise.
	(block_lookup): Constify.

1 files changed, 3 insertions, 3 deletions

diff --git a/gdb/frame.h b/gdb/frame.h
index 59564f9..4cc4858 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -665,8 +665,8 @@ extern void *frame_obstack_zalloc (unsigned long size);
 /* Create a regcache, and copy the frame's registers into it.  */
 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
 
-extern struct block *get_frame_block (struct frame_info *,
-                                      CORE_ADDR *addr_in_block);
+extern const struct block *get_frame_block (struct frame_info *,
+					    CORE_ADDR *addr_in_block);
 
 /* Return the `struct block' that belongs to the selected thread's
    selected frame.  If the inferior has no state, return NULL.
@@ -694,7 +694,7 @@ extern struct block *get_frame_block (struct frame_info *,
    it occurs in the CLI code and makes it possible for commands to
    work, even when the inferior has no state.  */
 
-extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
+extern const struct block *get_selected_block (CORE_ADDR *addr_in_block);
 
 extern struct symbol *get_frame_function (struct frame_info *);