alistair23-linux/scripts/kconfig/lkc_proto.h
Masahiro Yamada 00c864f890 kconfig: allow all config targets to write auto.conf if missing
Currently, only syncconfig creates or updates include/config/auto.conf
and some other files.  Other config targets create or update only the
.config file.

When you configure and build the kernel from a pristine source tree,
any config target is followed by syncconfig in the build stage since
include/config/auto.conf is missing.

We are moving compiler tests from Makefile to Kconfig.  It means that
parsing Kconfig files will be more costly since Kconfig invokes the
compiler commands internally.  Thus, we want to avoid invoking Kconfig
twice (one for *config to create the .config, and one for syncconfig
to synchronize the auto.conf).  If auto.conf does not exist, we can
generate all configuration files in the first configuration stage,
which will save the syncconfig in the build stage.

Please note this should be done only when auto.conf is missing.  If
*config blindly did this, time stamp files under include/config/ would
be unnecessarily touched, triggering unneeded rebuild of objects.

I assume a scenario like this:

 1. You have a source tree that has already been built
    with CONFIG_FOO disabled

 2. Run "make menuconfig" to enable CONFIG_FOO

 3. CONFIG_FOO turns out to be unnecessary.
    Run "make menuconfig" again to disable CONFIG_FOO

 4. Run "make"

In this case, include/config/foo.h should not be touched since there
is no change in CONFIG_FOO.  The sync process should be delayed until
the user really attempts to build the kernel.

This commit has another motivation; I want to suppress the 'No such
file or directory' warning from the 'include' directive.

The top-level Makefile includes auto.conf with '-include' directive,
like this:

  ifeq ($(dot-config),1)
  -include include/config/auto.conf
  endif

This looks strange because auto.conf is mandatory when dot-config is 1.
I guess only the reason of using '-include' is to suppress the warning
'include/config/auto.conf: No such file or directory' when building
from a clean tree.  However, this has a side-effect; Make considers
the files included by '-include' are optional.  Hence, Make continues
to build even if it fails to generate include/config/auto.conf.  I will
change this in the next commit, but the warning message is annoying.
(At least, kbuild test robot reports it as a regression.)

With this commit, Kconfig will generate all configuration files together
with the .config and I guess it is a solution good enough to suppress
the warning.

Note:
GNU Make 4.2 or later does not display the warning from the 'include'
directive if include files are successfully generated.  See GNU Make
commit 87a5f98d248f ("[SV 102] Don't show unnecessary include file
errors.")  However, older GNU Make versions are still widely used.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-25 23:25:30 +09:00

67 lines
2.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#include <stdarg.h>
/* confdata.c */
void conf_parse(const char *name);
int conf_read(const char *name);
int conf_read_simple(const char *name, int);
int conf_write_defconfig(const char *name);
int conf_write(const char *name);
int conf_write_autoconf(int overwrite);
bool conf_get_changed(void);
void conf_set_changed_callback(void (*fn)(void));
void conf_set_message_callback(void (*fn)(const char *s));
/* menu.c */
extern struct menu rootmenu;
bool menu_is_empty(struct menu *menu);
bool menu_is_visible(struct menu *menu);
bool menu_has_prompt(struct menu *menu);
const char * menu_get_prompt(struct menu *menu);
struct menu * menu_get_root_menu(struct menu *menu);
struct menu * menu_get_parent_menu(struct menu *menu);
bool menu_has_help(struct menu *menu);
const char * menu_get_help(struct menu *menu);
struct gstr get_relations_str(struct symbol **sym_arr, struct list_head *head);
void menu_get_ext_help(struct menu *menu, struct gstr *help);
/* symbol.c */
extern struct symbol * symbol_hash[SYMBOL_HASHSIZE];
struct symbol * sym_lookup(const char *name, int flags);
struct symbol * sym_find(const char *name);
const char * sym_escape_string_value(const char *in);
struct symbol ** sym_re_search(const char *pattern);
const char * sym_type_name(enum symbol_type type);
void sym_calc_value(struct symbol *sym);
enum symbol_type sym_get_type(struct symbol *sym);
bool sym_tristate_within_range(struct symbol *sym,tristate tri);
bool sym_set_tristate_value(struct symbol *sym,tristate tri);
tristate sym_toggle_tristate_value(struct symbol *sym);
bool sym_string_valid(struct symbol *sym, const char *newval);
bool sym_string_within_range(struct symbol *sym, const char *str);
bool sym_set_string_value(struct symbol *sym, const char *newval);
bool sym_is_changable(struct symbol *sym);
struct property * sym_get_choice_prop(struct symbol *sym);
const char * sym_get_string_value(struct symbol *sym);
const char * prop_get_type_name(enum prop_type type);
/* preprocess.c */
enum variable_flavor {
VAR_SIMPLE,
VAR_RECURSIVE,
VAR_APPEND,
};
void env_write_dep(FILE *f, const char *auto_conf_name);
void variable_add(const char *name, const char *value,
enum variable_flavor flavor);
void variable_all_del(void);
char *expand_string(const char *in);
char *expand_dollar(const char **str);
char *expand_one_token(const char **str);
/* expr.c */
void expr_print(struct expr *e, void (*fn)(void *, struct symbol *, const char *), void *data, int prevtoken);