gdb

gdb
	PR gdb/855:
	* NEWS: Add entry for macro commands.
	* Makefile.in (macrocmd.o): Add gdb_string.h.
	* macroscope.h (user_macro_scope): Declare.
	(default_macro_scope): Update documentation.
	(macro_user_macros): Declare.
	* c-lang.c (c_preprocess_and_parse): Always attempt macro lookup.
	Use user_macro_scope.
	(null_macro_lookup): Remove.
	* macrotab.h (macro_callback_fn): Declare.
	(macro_for_each): Likewise.
	(macro_allow_redefinitions): Likewise.
	* macrotab.c (foreach_macro): New function
	(macro_for_each): Likewise.
	(struct macro_table) <redef_ok>: New field.
	(macro_allow_redefinitions): New function.
	(new_macro_table): Update.
	(macro_define_function): Likewise.
	(macro_define_object): Likewise.
	* macroscope.c (user_macro_scope): New function.
	(default_macro_scope): Use it.
	(macro_user_macros): New global.
	(standard_macro_lookup): Look in macro_user_macros.
	(_initialize_macroscope): New function.
	* macroexp.h (macro_is_whitespace, macro_is_digit,
	macro_is_identifier_nondigit): Declare.
	* macroexp.c (macro_is_whitespace): Rename.  No longer static.
	(macro_is_digit): Likewise.
	(macro_is_identifier_nondigit): Likewise.
	(get_identifier): Update.
	(get_pp_number): Likewise.
	(get_token): Likewise.
	* macrocmd.c (skip_ws): New function.
	(extract_identifier): Likewise.
	(free_macro_definition_ptr): Likewise.
	(user_macros): Remove.
	(macro_define_command): Implement.
	(_initialize_macrocmd): Update.
	(macro_undef_command): Implement.
	(print_one_macro): New function.
	(macro_list_command): Implement.
gdb/doc
	* gdb.texinfo (Macros): Update.  Use @code rather than @command.
gdb/testsuite
	* gdb.base/macscp.exp: Add macro tests.