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, 5 insertions, 4 deletions

diff --git a/gdb/block.h b/gdb/block.h
index ca143a96d2..2c3012a22f 100644
--- a/gdb/block.h
+++ b/gdb/block.h
@@ -145,11 +145,12 @@ extern int block_inlined_p (const struct block *block);
 
 extern int contained_in (const struct block *, const struct block *);
 
-extern struct blockvector *blockvector_for_pc (CORE_ADDR, struct block **);
+extern struct blockvector *blockvector_for_pc (CORE_ADDR,
+					       const struct block **);
 
 extern struct blockvector *blockvector_for_pc_sect (CORE_ADDR, 
 						    struct obj_section *,
-						    struct block **,
+						    const struct block **,
                                                     struct symtab *);
 
 extern int blockvector_contains_pc (struct blockvector *bv, CORE_ADDR pc);
@@ -157,9 +158,9 @@ extern int blockvector_contains_pc (struct blockvector *bv, CORE_ADDR pc);
 extern struct call_site *call_site_for_pc (struct gdbarch *gdbarch,
 					   CORE_ADDR pc);
 
-extern struct block *block_for_pc (CORE_ADDR);
+extern const struct block *block_for_pc (CORE_ADDR);
 
-extern struct block *block_for_pc_sect (CORE_ADDR, struct obj_section *);
+extern const struct block *block_for_pc_sect (CORE_ADDR, struct obj_section *);
 
 extern const char *block_scope (const struct block *block);