[v2,09/21] kconfig: add 'macro' keyword to support user-defined function

Message ID 1522128575-5326-10-git-send-email-yamada.masahiro@socionext.com
State New
Headers show
Series
  • kconfig: move compiler capability tests to Kconfig
Related show

Commit Message

Masahiro Yamada March 27, 2018, 5:29 a.m.
Now, we got a basic ability to test compiler capability in Kconfig.

config CC_HAS_STACKPROTECTOR
        def_bool $(shell (($CC -Werror -fstack-protector -c -x c /dev/null -o /dev/null) && echo y) || echo n)

This works, but it is ugly to repeat this long boilerplate.

We want to describe like this:

config CC_HAS_STACKPROTECTOR
        bool
        default $(cc-option -fstack-protector)

It is straight-forward to add a new function, but I do not like to
hard-code specialized functions like this.  Hence, here is another
feature to add functions from Kconfig files.

A user-defined function is defined with a special keyword 'macro'.
It can be referenced in the same way as built-in functions.  This
feature was also inspired by Makefile where user-defined functions
are referenced by $(call func-name, args...), but I omitted the 'call'
to makes it shorter.

The macro definition can contain $(1), $(2), ... which will be replaced
with arguments from the caller.  The macro works just as a textual
shorthand, which is also expanded in the lexer phase.

[Example Code]

  macro success $(shell ($(1) && echo y) || echo n)

  config TRUE
          bool "true"
          default $(success true)

  config FALSE
          bool "false"
          default $(success false)

[Result]

  $ make -s alldefconfig
  $ tail -n 2 .config
  CONFIG_TRUE=y
  # CONFIG_FALSE is not set

[Example Code]

  macro success $(shell ($(1) && echo y) || echo n)

  macro cc-option $(success $CC -Werror $(1) -c -x c /dev/null -o /dev/null)

  config CC_HAS_STACKPROTECTOR
          def_bool $(cc-option -fstack-protector)

[Result]
  $ make -s alldefconfig
  $ tail -n 1 .config
  CONFIG_CC_HAS_STACKPROTECTOR=y

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

---

Reminder for myself:
Update Documentation/kbuild/kconfig-language.txt

Changes in v2:
  - Use 'macro' directly instead of inside the string type symbol.

 scripts/kconfig/function.c  | 59 +++++++++++++++++++++++++++++++++++++++++++--
 scripts/kconfig/lkc_proto.h |  1 +
 scripts/kconfig/zconf.l     | 31 ++++++++++++++++++++++++
 3 files changed, 89 insertions(+), 2 deletions(-)

-- 
2.7.4

Comments

Kees Cook March 28, 2018, 3:45 a.m. | #1
On Mon, Mar 26, 2018 at 10:29 PM, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> Now, we got a basic ability to test compiler capability in Kconfig.

>

> config CC_HAS_STACKPROTECTOR

>         def_bool $(shell (($CC -Werror -fstack-protector -c -x c /dev/null -o /dev/null) && echo y) || echo n)

>

> This works, but it is ugly to repeat this long boilerplate.

>

> We want to describe like this:

>

> config CC_HAS_STACKPROTECTOR

>         bool

>         default $(cc-option -fstack-protector)

>

> It is straight-forward to add a new function, but I do not like to

> hard-code specialized functions like this.  Hence, here is another

> feature to add functions from Kconfig files.

>

> A user-defined function is defined with a special keyword 'macro'.

> It can be referenced in the same way as built-in functions.  This

> feature was also inspired by Makefile where user-defined functions

> are referenced by $(call func-name, args...), but I omitted the 'call'

> to makes it shorter.

>

> The macro definition can contain $(1), $(2), ... which will be replaced

> with arguments from the caller.  The macro works just as a textual

> shorthand, which is also expanded in the lexer phase.

>

> [Example Code]

>

>   macro success $(shell ($(1) && echo y) || echo n)

>

>   config TRUE

>           bool "true"

>           default $(success true)

>

>   config FALSE

>           bool "false"

>           default $(success false)

>

> [Result]

>

>   $ make -s alldefconfig

>   $ tail -n 2 .config

>   CONFIG_TRUE=y

>   # CONFIG_FALSE is not set

>

> [Example Code]

>

>   macro success $(shell ($(1) && echo y) || echo n)

>

>   macro cc-option $(success $CC -Werror $(1) -c -x c /dev/null -o /dev/null)

>

>   config CC_HAS_STACKPROTECTOR

>           def_bool $(cc-option -fstack-protector)

>

> [Result]

>   $ make -s alldefconfig

>   $ tail -n 1 .config

>   CONFIG_CC_HAS_STACKPROTECTOR=y

>

> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>


Cool, I like this "macro" idea for keeping this clean.

> ---

>

> Reminder for myself:

> Update Documentation/kbuild/kconfig-language.txt


Yes please. :)

Otherwise, looks good!

-Kees

-- 
Kees Cook
Pixel Security
Ulf Magnusson April 1, 2018, 6:05 a.m. | #2
On Tue, Mar 27, 2018 at 7:29 AM, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> Now, we got a basic ability to test compiler capability in Kconfig.

>

> config CC_HAS_STACKPROTECTOR

>         def_bool $(shell (($CC -Werror -fstack-protector -c -x c /dev/null -o /dev/null) && echo y) || echo n)

>

> This works, but it is ugly to repeat this long boilerplate.

>

> We want to describe like this:

>

> config CC_HAS_STACKPROTECTOR

>         bool

>         default $(cc-option -fstack-protector)

>

> It is straight-forward to add a new function, but I do not like to

> hard-code specialized functions like this.  Hence, here is another

> feature to add functions from Kconfig files.

>

> A user-defined function is defined with a special keyword 'macro'.

> It can be referenced in the same way as built-in functions.  This

> feature was also inspired by Makefile where user-defined functions

> are referenced by $(call func-name, args...), but I omitted the 'call'

> to makes it shorter.

>

> The macro definition can contain $(1), $(2), ... which will be replaced

> with arguments from the caller.  The macro works just as a textual

> shorthand, which is also expanded in the lexer phase.

>

> [Example Code]

>

>   macro success $(shell ($(1) && echo y) || echo n)

>

>   config TRUE

>           bool "true"

>           default $(success true)

>

>   config FALSE

>           bool "false"

>           default $(success false)

>

> [Result]

>

>   $ make -s alldefconfig

>   $ tail -n 2 .config

>   CONFIG_TRUE=y

>   # CONFIG_FALSE is not set

>

> [Example Code]

>

>   macro success $(shell ($(1) && echo y) || echo n)

>

>   macro cc-option $(success $CC -Werror $(1) -c -x c /dev/null -o /dev/null)

>

>   config CC_HAS_STACKPROTECTOR

>           def_bool $(cc-option -fstack-protector)

>

> [Result]

>   $ make -s alldefconfig

>   $ tail -n 1 .config

>   CONFIG_CC_HAS_STACKPROTECTOR=y

>

> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

> ---

>

> Reminder for myself:

> Update Documentation/kbuild/kconfig-language.txt

>

> Changes in v2:

>   - Use 'macro' directly instead of inside the string type symbol.

>

>  scripts/kconfig/function.c  | 59 +++++++++++++++++++++++++++++++++++++++++++--

>  scripts/kconfig/lkc_proto.h |  1 +

>  scripts/kconfig/zconf.l     | 31 ++++++++++++++++++++++++

>  3 files changed, 89 insertions(+), 2 deletions(-)

>

> diff --git a/scripts/kconfig/function.c b/scripts/kconfig/function.c

> index 913685f..389bb44 100644

> --- a/scripts/kconfig/function.c

> +++ b/scripts/kconfig/function.c

> @@ -15,6 +15,7 @@ static LIST_HEAD(function_list);

>  struct function {

>         char *name;

>         char *(*func)(struct function *f, int argc, char *argv[]);

> +       char *macro;

>         struct list_head node;

>  };

>

> @@ -31,7 +32,8 @@ static struct function *func_lookup(const char *name)

>  }

>

>  static void func_add(const char *name,

> -                    char *(*func)(struct function *f, int argc, char *argv[]))

> +                    char *(*func)(struct function *f, int argc, char *argv[]),

> +                    const char *macro)

>  {

>         struct function *f;

>

> @@ -44,6 +46,7 @@ static void func_add(const char *name,

>         f = xmalloc(sizeof(*f));

>         f->name = xstrdup(name);

>         f->func = func;

> +       f->macro = macro ? xstrdup(macro) : NULL;

>

>         list_add_tail(&f->node, &function_list);

>  }

> @@ -51,6 +54,7 @@ static void func_add(const char *name,

>  static void func_del(struct function *f)

>  {

>         list_del(&f->node);

> +       free(f->macro);

>         free(f->name);

>         free(f);

>  }

> @@ -108,6 +112,57 @@ char *func_eval_n(const char *func, size_t n)

>         return res;

>  }

>

> +/* run user-defined function */

> +static char *do_macro(struct function *f, int argc, char *argv[])

> +{

> +       char *new;

> +       char *src, *p, *res;

> +       size_t newlen;

> +       int n;

> +

> +       new = xmalloc(1);

> +       *new = 0;


new = '\0' would be consistent with the rest of the code.

> +

> +       /*

> +        * This is a format string. $(1), $(2), ... must be replaced with

> +        * function arguments.

> +        */

> +       src = f->macro;

> +       p = src;

> +

> +       while ((p = strstr(p, "$("))) {

> +               if (isdigit(p[2]) && p[3] == ')') {

> +                       n = p[2] - '0';

> +                       if (n < argc) {

> +                               newlen = strlen(new) + (p - src) +

> +                                                       strlen(argv[n]) + 1;

> +                               new = xrealloc(new, newlen);

> +                               strncat(new, src, p - src);

> +                               strcat(new, argv[n]);

> +                               src = p + 4;

> +                       }


Might be nice to warn when a macro call has missing arguments.

> +                       p += 2;

> +               }

> +               p += 2;

> +       }


I had to stare at this for a while to see how it worked. What do you
think of this tweak?

while ((p = strstr(p, "$("))) {
        if (isdigit(p[2]) && p[3] == ')') {
                n = p[2] - '0';
                if (n < argc) {
                        newlen = strlen(new) + (p - src) +
                                                strlen(argv[n]) + 1;
                        new = xrealloc(new, newlen);
                        strncat(new, src, p - src);
                        strcat(new, argv[n]);

                        /*
                         * Jump past macro parameter ("$(n)") and remember the
                         * position
                         */
                        p += 4;
                        src = p;

                        continue;
                }
        }

        /* Jump past "$(" that isn't from a macro parameter */
        p += 2;
}

> +

> +       newlen = strlen(new) + strlen(src) + 1;

> +       new = xrealloc(new, newlen);

> +       strcat(new, src);

> +

> +       res = expand_string_value(new);

> +

> +       free(new);

> +

> +       return res;

> +}

> +

> +/* add user-defined function (macro) */

> +void func_add_macro(const char *name, const char *macro)

> +{

> +       func_add(name, do_macro, macro);

> +}

> +

>  /* built-in functions */

>  static char *do_shell(struct function *f, int argc, char *argv[])

>  {

> @@ -157,7 +212,7 @@ static char *do_shell(struct function *f, int argc, char *argv[])

>  void func_init(void)

>  {

>         /* register built-in functions */

> -       func_add("shell", do_shell);

> +       func_add("shell", do_shell, NULL);

>  }

>

>  void func_exit(void)

> diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h

> index 09a4f53..48699c0 100644

> --- a/scripts/kconfig/lkc_proto.h

> +++ b/scripts/kconfig/lkc_proto.h

> @@ -50,6 +50,7 @@ const char * prop_get_type_name(enum prop_type type);

>

>  /* function.c */

>  char *func_eval_n(const char *func, size_t n);

> +void func_add_macro(const char *name, const char *macro);

>  void func_init(void);

>  void func_exit(void);

>

> diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l

> index 551ca47..6a18c68 100644

> --- a/scripts/kconfig/zconf.l

> +++ b/scripts/kconfig/zconf.l

> @@ -74,6 +74,36 @@ static void warn_ignored_character(char chr)

>                 "%s:%d:warning: ignoring unsupported character '%c'\n",

>                 zconf_curname(), zconf_lineno(), chr);

>  }

> +

> +static void handle_macro(const char *text)

> +{

> +       char *p, *q;

> +

> +       while (isspace(*text))

> +               text++;

> +

> +       p = xstrdup(text);

> +

> +       q = p;

> +       while (isalnum(*q) || *q == '_' || *q == '-')

> +               q++;

> +

> +       if (q == p || !*q) {

> +               yyerror("invalid\n");

> +               goto free;

> +       }

> +

> +       *q = '\0';

> +

> +       q++;

> +       while (isspace(*q))

> +               q++;

> +

> +       func_add_macro(p, q);

> +free:

> +       free(p);

> +}

> +

>  %}

>

>  n      [A-Za-z0-9_-]

> @@ -82,6 +112,7 @@ n    [A-Za-z0-9_-]

>         int str = 0;

>         int ts, i;

>

> +"macro"[ \t].* handle_macro(yytext + 6);

>  [ \t]*#.*\n    |

>  [ \t]*\n       {

>         return T_EOL;

> --

> 2.7.4

>


Cheers,
Ulf
Ulf Magnusson April 1, 2018, 6:49 a.m. | #3
On Sun, Apr 1, 2018 at 8:05 AM, Ulf Magnusson <ulfalizer@gmail.com> wrote:
> On Tue, Mar 27, 2018 at 7:29 AM, Masahiro Yamada

> <yamada.masahiro@socionext.com> wrote:

>> Now, we got a basic ability to test compiler capability in Kconfig.

>>

>> config CC_HAS_STACKPROTECTOR

>>         def_bool $(shell (($CC -Werror -fstack-protector -c -x c /dev/null -o /dev/null) && echo y) || echo n)

>>

>> This works, but it is ugly to repeat this long boilerplate.

>>

>> We want to describe like this:

>>

>> config CC_HAS_STACKPROTECTOR

>>         bool

>>         default $(cc-option -fstack-protector)

>>

>> It is straight-forward to add a new function, but I do not like to

>> hard-code specialized functions like this.  Hence, here is another

>> feature to add functions from Kconfig files.

>>

>> A user-defined function is defined with a special keyword 'macro'.

>> It can be referenced in the same way as built-in functions.  This

>> feature was also inspired by Makefile where user-defined functions

>> are referenced by $(call func-name, args...), but I omitted the 'call'

>> to makes it shorter.

>>

>> The macro definition can contain $(1), $(2), ... which will be replaced

>> with arguments from the caller.  The macro works just as a textual

>> shorthand, which is also expanded in the lexer phase.

>>

>> [Example Code]

>>

>>   macro success $(shell ($(1) && echo y) || echo n)

>>

>>   config TRUE

>>           bool "true"

>>           default $(success true)

>>

>>   config FALSE

>>           bool "false"

>>           default $(success false)

>>

>> [Result]

>>

>>   $ make -s alldefconfig

>>   $ tail -n 2 .config

>>   CONFIG_TRUE=y

>>   # CONFIG_FALSE is not set

>>

>> [Example Code]

>>

>>   macro success $(shell ($(1) && echo y) || echo n)

>>

>>   macro cc-option $(success $CC -Werror $(1) -c -x c /dev/null -o /dev/null)

>>

>>   config CC_HAS_STACKPROTECTOR

>>           def_bool $(cc-option -fstack-protector)

>>

>> [Result]

>>   $ make -s alldefconfig

>>   $ tail -n 1 .config

>>   CONFIG_CC_HAS_STACKPROTECTOR=y

>>

>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

>> ---

>>

>> Reminder for myself:

>> Update Documentation/kbuild/kconfig-language.txt

>>

>> Changes in v2:

>>   - Use 'macro' directly instead of inside the string type symbol.

>>

>>  scripts/kconfig/function.c  | 59 +++++++++++++++++++++++++++++++++++++++++++--

>>  scripts/kconfig/lkc_proto.h |  1 +

>>  scripts/kconfig/zconf.l     | 31 ++++++++++++++++++++++++

>>  3 files changed, 89 insertions(+), 2 deletions(-)

>>

>> diff --git a/scripts/kconfig/function.c b/scripts/kconfig/function.c

>> index 913685f..389bb44 100644

>> --- a/scripts/kconfig/function.c

>> +++ b/scripts/kconfig/function.c

>> @@ -15,6 +15,7 @@ static LIST_HEAD(function_list);

>>  struct function {

>>         char *name;

>>         char *(*func)(struct function *f, int argc, char *argv[]);

>> +       char *macro;

>>         struct list_head node;

>>  };

>>

>> @@ -31,7 +32,8 @@ static struct function *func_lookup(const char *name)

>>  }

>>

>>  static void func_add(const char *name,

>> -                    char *(*func)(struct function *f, int argc, char *argv[]))

>> +                    char *(*func)(struct function *f, int argc, char *argv[]),

>> +                    const char *macro)

>>  {

>>         struct function *f;

>>

>> @@ -44,6 +46,7 @@ static void func_add(const char *name,

>>         f = xmalloc(sizeof(*f));

>>         f->name = xstrdup(name);

>>         f->func = func;

>> +       f->macro = macro ? xstrdup(macro) : NULL;

>>

>>         list_add_tail(&f->node, &function_list);

>>  }

>> @@ -51,6 +54,7 @@ static void func_add(const char *name,

>>  static void func_del(struct function *f)

>>  {

>>         list_del(&f->node);

>> +       free(f->macro);

>>         free(f->name);

>>         free(f);

>>  }

>> @@ -108,6 +112,57 @@ char *func_eval_n(const char *func, size_t n)

>>         return res;

>>  }

>>

>> +/* run user-defined function */

>> +static char *do_macro(struct function *f, int argc, char *argv[])

>> +{

>> +       char *new;

>> +       char *src, *p, *res;

>> +       size_t newlen;

>> +       int n;

>> +

>> +       new = xmalloc(1);

>> +       *new = 0;

>

> new = '\0' would be consistent with the rest of the code.

>

>> +

>> +       /*

>> +        * This is a format string. $(1), $(2), ... must be replaced with

>> +        * function arguments.

>> +        */

>> +       src = f->macro;

>> +       p = src;

>> +

>> +       while ((p = strstr(p, "$("))) {

>> +               if (isdigit(p[2]) && p[3] == ')') {

>> +                       n = p[2] - '0';

>> +                       if (n < argc) {

>> +                               newlen = strlen(new) + (p - src) +

>> +                                                       strlen(argv[n]) + 1;

>> +                               new = xrealloc(new, newlen);

>> +                               strncat(new, src, p - src);

>> +                               strcat(new, argv[n]);

>> +                               src = p + 4;

>> +                       }

>

> Might be nice to warn when a macro call has missing arguments.


Or just error out. There isn't even any backwards compatibility to
think of, and that'd make the code even simpler. Something like this:

while ((p = strstr(p, "$("))) {
        if (isdigit(p[2]) && p[3] == ')') {
                n = p[2] - '0';
                if (n >= argc)
                        *ERROR*

                newlen = strlen(new) + (p - src) + strlen(argv[n]) + 1;
                new = xrealloc(new, newlen);
                strncat(new, src, p - src);
                strcat(new, argv[n]);

                /*
                 * Jump past macro parameter ("$(n)") and remember the new
                 * position
                 */
                p += 4;
                src = p;
        }
        else {
                /* Jump past "$(" that isn't from a macro parameter */
                p += 2;
        }
}

>

>> +                       p += 2;

>> +               }

>> +               p += 2;

>> +       }

>

> I had to stare at this for a while to see how it worked. What do you

> think of this tweak?

>

> while ((p = strstr(p, "$("))) {

>         if (isdigit(p[2]) && p[3] == ')') {

>                 n = p[2] - '0';

>                 if (n < argc) {

>                         newlen = strlen(new) + (p - src) +

>                                                 strlen(argv[n]) + 1;

>                         new = xrealloc(new, newlen);

>                         strncat(new, src, p - src);

>                         strcat(new, argv[n]);

>

>                         /*

>                          * Jump past macro parameter ("$(n)") and remember the

>                          * position

>                          */

>                         p += 4;

>                         src = p;

>

>                         continue;

>                 }

>         }

>

>         /* Jump past "$(" that isn't from a macro parameter */

>         p += 2;

> }

>

>> +

>> +       newlen = strlen(new) + strlen(src) + 1;

>> +       new = xrealloc(new, newlen);

>> +       strcat(new, src);

>> +

>> +       res = expand_string_value(new);

>> +

>> +       free(new);

>> +

>> +       return res;

>> +}

>> +

>> +/* add user-defined function (macro) */

>> +void func_add_macro(const char *name, const char *macro)

>> +{

>> +       func_add(name, do_macro, macro);

>> +}

>> +

>>  /* built-in functions */

>>  static char *do_shell(struct function *f, int argc, char *argv[])

>>  {

>> @@ -157,7 +212,7 @@ static char *do_shell(struct function *f, int argc, char *argv[])

>>  void func_init(void)

>>  {

>>         /* register built-in functions */

>> -       func_add("shell", do_shell);

>> +       func_add("shell", do_shell, NULL);

>>  }

>>

>>  void func_exit(void)

>> diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h

>> index 09a4f53..48699c0 100644

>> --- a/scripts/kconfig/lkc_proto.h

>> +++ b/scripts/kconfig/lkc_proto.h

>> @@ -50,6 +50,7 @@ const char * prop_get_type_name(enum prop_type type);

>>

>>  /* function.c */

>>  char *func_eval_n(const char *func, size_t n);

>> +void func_add_macro(const char *name, const char *macro);

>>  void func_init(void);

>>  void func_exit(void);

>>

>> diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l

>> index 551ca47..6a18c68 100644

>> --- a/scripts/kconfig/zconf.l

>> +++ b/scripts/kconfig/zconf.l

>> @@ -74,6 +74,36 @@ static void warn_ignored_character(char chr)

>>                 "%s:%d:warning: ignoring unsupported character '%c'\n",

>>                 zconf_curname(), zconf_lineno(), chr);

>>  }

>> +

>> +static void handle_macro(const char *text)

>> +{

>> +       char *p, *q;

>> +

>> +       while (isspace(*text))

>> +               text++;

>> +

>> +       p = xstrdup(text);

>> +

>> +       q = p;

>> +       while (isalnum(*q) || *q == '_' || *q == '-')

>> +               q++;

>> +

>> +       if (q == p || !*q) {

>> +               yyerror("invalid\n");

>> +               goto free;

>> +       }

>> +

>> +       *q = '\0';

>> +

>> +       q++;

>> +       while (isspace(*q))

>> +               q++;

>> +

>> +       func_add_macro(p, q);

>> +free:

>> +       free(p);

>> +}

>> +

>>  %}

>>

>>  n      [A-Za-z0-9_-]

>> @@ -82,6 +112,7 @@ n    [A-Za-z0-9_-]

>>         int str = 0;

>>         int ts, i;

>>

>> +"macro"[ \t].* handle_macro(yytext + 6);

>>  [ \t]*#.*\n    |

>>  [ \t]*\n       {

>>         return T_EOL;

>> --

>> 2.7.4

>>

>

> Cheers,

> Ulf
Masahiro Yamada April 13, 2018, 5:44 a.m. | #4
2018-04-01 15:05 GMT+09:00 Ulf Magnusson <ulfalizer@gmail.com>:
> On Tue, Mar 27, 2018 at 7:29 AM, Masahiro Yamada

> <yamada.masahiro@socionext.com> wrote:

>> Now, we got a basic ability to test compiler capability in Kconfig.

>>

>> config CC_HAS_STACKPROTECTOR

>>         def_bool $(shell (($CC -Werror -fstack-protector -c -x c /dev/null -o /dev/null) && echo y) || echo n)

>>

>> This works, but it is ugly to repeat this long boilerplate.

>>

>> We want to describe like this:

>>

>> config CC_HAS_STACKPROTECTOR

>>         bool

>>         default $(cc-option -fstack-protector)

>>

>> It is straight-forward to add a new function, but I do not like to

>> hard-code specialized functions like this.  Hence, here is another

>> feature to add functions from Kconfig files.

>>

>> A user-defined function is defined with a special keyword 'macro'.

>> It can be referenced in the same way as built-in functions.  This

>> feature was also inspired by Makefile where user-defined functions

>> are referenced by $(call func-name, args...), but I omitted the 'call'

>> to makes it shorter.

>>

>> The macro definition can contain $(1), $(2), ... which will be replaced

>> with arguments from the caller.  The macro works just as a textual

>> shorthand, which is also expanded in the lexer phase.

>>

>> [Example Code]

>>

>>   macro success $(shell ($(1) && echo y) || echo n)

>>

>>   config TRUE

>>           bool "true"

>>           default $(success true)

>>

>>   config FALSE

>>           bool "false"

>>           default $(success false)

>>

>> [Result]

>>

>>   $ make -s alldefconfig

>>   $ tail -n 2 .config

>>   CONFIG_TRUE=y

>>   # CONFIG_FALSE is not set

>>

>> [Example Code]

>>

>>   macro success $(shell ($(1) && echo y) || echo n)

>>

>>   macro cc-option $(success $CC -Werror $(1) -c -x c /dev/null -o /dev/null)

>>

>>   config CC_HAS_STACKPROTECTOR

>>           def_bool $(cc-option -fstack-protector)

>>

>> [Result]

>>   $ make -s alldefconfig

>>   $ tail -n 1 .config

>>   CONFIG_CC_HAS_STACKPROTECTOR=y

>>

>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

>> ---

>>

>> Reminder for myself:

>> Update Documentation/kbuild/kconfig-language.txt

>>

>> Changes in v2:

>>   - Use 'macro' directly instead of inside the string type symbol.

>>

>>  scripts/kconfig/function.c  | 59 +++++++++++++++++++++++++++++++++++++++++++--

>>  scripts/kconfig/lkc_proto.h |  1 +

>>  scripts/kconfig/zconf.l     | 31 ++++++++++++++++++++++++

>>  3 files changed, 89 insertions(+), 2 deletions(-)

>>

>> diff --git a/scripts/kconfig/function.c b/scripts/kconfig/function.c

>> index 913685f..389bb44 100644

>> --- a/scripts/kconfig/function.c

>> +++ b/scripts/kconfig/function.c

>> @@ -15,6 +15,7 @@ static LIST_HEAD(function_list);

>>  struct function {

>>         char *name;

>>         char *(*func)(struct function *f, int argc, char *argv[]);

>> +       char *macro;

>>         struct list_head node;

>>  };

>>

>> @@ -31,7 +32,8 @@ static struct function *func_lookup(const char *name)

>>  }

>>

>>  static void func_add(const char *name,

>> -                    char *(*func)(struct function *f, int argc, char *argv[]))

>> +                    char *(*func)(struct function *f, int argc, char *argv[]),

>> +                    const char *macro)

>>  {

>>         struct function *f;

>>

>> @@ -44,6 +46,7 @@ static void func_add(const char *name,

>>         f = xmalloc(sizeof(*f));

>>         f->name = xstrdup(name);

>>         f->func = func;

>> +       f->macro = macro ? xstrdup(macro) : NULL;

>>

>>         list_add_tail(&f->node, &function_list);

>>  }

>> @@ -51,6 +54,7 @@ static void func_add(const char *name,

>>  static void func_del(struct function *f)

>>  {

>>         list_del(&f->node);

>> +       free(f->macro);

>>         free(f->name);

>>         free(f);

>>  }

>> @@ -108,6 +112,57 @@ char *func_eval_n(const char *func, size_t n)

>>         return res;

>>  }

>>

>> +/* run user-defined function */

>> +static char *do_macro(struct function *f, int argc, char *argv[])

>> +{

>> +       char *new;

>> +       char *src, *p, *res;

>> +       size_t newlen;

>> +       int n;

>> +

>> +       new = xmalloc(1);

>> +       *new = 0;

>

> new = '\0' would be consistent with the rest of the code.

>

>> +

>> +       /*

>> +        * This is a format string. $(1), $(2), ... must be replaced with

>> +        * function arguments.

>> +        */

>> +       src = f->macro;

>> +       p = src;

>> +

>> +       while ((p = strstr(p, "$("))) {

>> +               if (isdigit(p[2]) && p[3] == ')') {

>> +                       n = p[2] - '0';

>> +                       if (n < argc) {

>> +                               newlen = strlen(new) + (p - src) +

>> +                                                       strlen(argv[n]) + 1;

>> +                               new = xrealloc(new, newlen);

>> +                               strncat(new, src, p - src);

>> +                               strcat(new, argv[n]);

>> +                               src = p + 4;

>> +                       }

>

> Might be nice to warn when a macro call has missing arguments.



I made this a feature as we see in Make.

In Makefile, it is allowed to pass more or less arguments.

cc-option is often used with one flag.

   $(call cc-option,-fno-PIE)

But, it can take one more as a fall-back compiler option.

   $(call cc-option,-mtune=marvell-f,-mtune=xscale)


Of course, we can describe the first one like follows
just to pass a blank parameter as the last parameter.

   $(call cc-option,-fno-PIE,)




>> +                       p += 2;

>> +               }

>> +               p += 2;

>> +       }

>

> I had to stare at this for a while to see how it worked. What do you

> think of this tweak?

>

> while ((p = strstr(p, "$("))) {

>         if (isdigit(p[2]) && p[3] == ')') {

>                 n = p[2] - '0';

>                 if (n < argc) {

>                         newlen = strlen(new) + (p - src) +

>                                                 strlen(argv[n]) + 1;

>                         new = xrealloc(new, newlen);

>                         strncat(new, src, p - src);

>                         strcat(new, argv[n]);

>

>                         /*

>                          * Jump past macro parameter ("$(n)") and remember the

>                          * position

>                          */

>                         p += 4;

>                         src = p;

>

>                         continue;

>                 }

>         }

>

>         /* Jump past "$(" that isn't from a macro parameter */

>         p += 2;

> }



Will work, but I re-implemented the parser in v3.


>> +

>> +       newlen = strlen(new) + strlen(src) + 1;

>> +       new = xrealloc(new, newlen);

>> +       strcat(new, src);

>> +

>> +       res = expand_string_value(new);

>> +

>> +       free(new);

>> +

>> +       return res;

>> +}

>> +

>> +/* add user-defined function (macro) */

>> +void func_add_macro(const char *name, const char *macro)

>> +{

>> +       func_add(name, do_macro, macro);

>> +}

>> +

>>  /* built-in functions */

>>  static char *do_shell(struct function *f, int argc, char *argv[])

>>  {

>> @@ -157,7 +212,7 @@ static char *do_shell(struct function *f, int argc, char *argv[])

>>  void func_init(void)

>>  {

>>         /* register built-in functions */

>> -       func_add("shell", do_shell);

>> +       func_add("shell", do_shell, NULL);

>>  }

>>

>>  void func_exit(void)

>> diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h

>> index 09a4f53..48699c0 100644

>> --- a/scripts/kconfig/lkc_proto.h

>> +++ b/scripts/kconfig/lkc_proto.h

>> @@ -50,6 +50,7 @@ const char * prop_get_type_name(enum prop_type type);

>>

>>  /* function.c */

>>  char *func_eval_n(const char *func, size_t n);

>> +void func_add_macro(const char *name, const char *macro);

>>  void func_init(void);

>>  void func_exit(void);

>>

>> diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l

>> index 551ca47..6a18c68 100644

>> --- a/scripts/kconfig/zconf.l

>> +++ b/scripts/kconfig/zconf.l

>> @@ -74,6 +74,36 @@ static void warn_ignored_character(char chr)

>>                 "%s:%d:warning: ignoring unsupported character '%c'\n",

>>                 zconf_curname(), zconf_lineno(), chr);

>>  }

>> +

>> +static void handle_macro(const char *text)

>> +{

>> +       char *p, *q;

>> +

>> +       while (isspace(*text))

>> +               text++;

>> +

>> +       p = xstrdup(text);

>> +

>> +       q = p;

>> +       while (isalnum(*q) || *q == '_' || *q == '-')

>> +               q++;

>> +

>> +       if (q == p || !*q) {

>> +               yyerror("invalid\n");

>> +               goto free;

>> +       }

>> +

>> +       *q = '\0';

>> +

>> +       q++;

>> +       while (isspace(*q))

>> +               q++;

>> +

>> +       func_add_macro(p, q);

>> +free:

>> +       free(p);

>> +}

>> +

>>  %}

>>

>>  n      [A-Za-z0-9_-]

>> @@ -82,6 +112,7 @@ n    [A-Za-z0-9_-]

>>         int str = 0;

>>         int ts, i;

>>

>> +"macro"[ \t].* handle_macro(yytext + 6);

>>  [ \t]*#.*\n    |

>>  [ \t]*\n       {

>>         return T_EOL;

>> --

>> 2.7.4

>>

>

> Cheers,

> Ulf

> --

> To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in

> the body of a message to majordomo@vger.kernel.org

> More majordomo info at  http://vger.kernel.org/majordomo-info.html




-- 
Best Regards
Masahiro Yamada

Patch

diff --git a/scripts/kconfig/function.c b/scripts/kconfig/function.c
index 913685f..389bb44 100644
--- a/scripts/kconfig/function.c
+++ b/scripts/kconfig/function.c
@@ -15,6 +15,7 @@  static LIST_HEAD(function_list);
 struct function {
 	char *name;
 	char *(*func)(struct function *f, int argc, char *argv[]);
+	char *macro;
 	struct list_head node;
 };
 
@@ -31,7 +32,8 @@  static struct function *func_lookup(const char *name)
 }
 
 static void func_add(const char *name,
-		     char *(*func)(struct function *f, int argc, char *argv[]))
+		     char *(*func)(struct function *f, int argc, char *argv[]),
+		     const char *macro)
 {
 	struct function *f;
 
@@ -44,6 +46,7 @@  static void func_add(const char *name,
 	f = xmalloc(sizeof(*f));
 	f->name = xstrdup(name);
 	f->func = func;
+	f->macro = macro ? xstrdup(macro) : NULL;
 
 	list_add_tail(&f->node, &function_list);
 }
@@ -51,6 +54,7 @@  static void func_add(const char *name,
 static void func_del(struct function *f)
 {
 	list_del(&f->node);
+	free(f->macro);
 	free(f->name);
 	free(f);
 }
@@ -108,6 +112,57 @@  char *func_eval_n(const char *func, size_t n)
 	return res;
 }
 
+/* run user-defined function */
+static char *do_macro(struct function *f, int argc, char *argv[])
+{
+	char *new;
+	char *src, *p, *res;
+	size_t newlen;
+	int n;
+
+	new = xmalloc(1);
+	*new = 0;
+
+	/*
+	 * This is a format string. $(1), $(2), ... must be replaced with
+	 * function arguments.
+	 */
+	src = f->macro;
+	p = src;
+
+	while ((p = strstr(p, "$("))) {
+		if (isdigit(p[2]) && p[3] == ')') {
+			n = p[2] - '0';
+			if (n < argc) {
+				newlen = strlen(new) + (p - src) +
+							strlen(argv[n]) + 1;
+				new = xrealloc(new, newlen);
+				strncat(new, src, p - src);
+				strcat(new, argv[n]);
+				src = p + 4;
+			}
+			p += 2;
+		}
+		p += 2;
+	}
+
+	newlen = strlen(new) + strlen(src) + 1;
+	new = xrealloc(new, newlen);
+	strcat(new, src);
+
+	res = expand_string_value(new);
+
+	free(new);
+
+	return res;
+}
+
+/* add user-defined function (macro) */
+void func_add_macro(const char *name, const char *macro)
+{
+	func_add(name, do_macro, macro);
+}
+
 /* built-in functions */
 static char *do_shell(struct function *f, int argc, char *argv[])
 {
@@ -157,7 +212,7 @@  static char *do_shell(struct function *f, int argc, char *argv[])
 void func_init(void)
 {
 	/* register built-in functions */
-	func_add("shell", do_shell);
+	func_add("shell", do_shell, NULL);
 }
 
 void func_exit(void)
diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h
index 09a4f53..48699c0 100644
--- a/scripts/kconfig/lkc_proto.h
+++ b/scripts/kconfig/lkc_proto.h
@@ -50,6 +50,7 @@  const char * prop_get_type_name(enum prop_type type);
 
 /* function.c */
 char *func_eval_n(const char *func, size_t n);
+void func_add_macro(const char *name, const char *macro);
 void func_init(void);
 void func_exit(void);
 
diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
index 551ca47..6a18c68 100644
--- a/scripts/kconfig/zconf.l
+++ b/scripts/kconfig/zconf.l
@@ -74,6 +74,36 @@  static void warn_ignored_character(char chr)
 	        "%s:%d:warning: ignoring unsupported character '%c'\n",
 	        zconf_curname(), zconf_lineno(), chr);
 }
+
+static void handle_macro(const char *text)
+{
+	char *p, *q;
+
+	while (isspace(*text))
+		text++;
+
+	p = xstrdup(text);
+
+	q = p;
+	while (isalnum(*q) || *q == '_' || *q == '-')
+		q++;
+
+	if (q == p || !*q) {
+		yyerror("invalid\n");
+		goto free;
+	}
+
+	*q = '\0';
+
+	q++;
+	while (isspace(*q))
+		q++;
+
+	func_add_macro(p, q);
+free:
+	free(p);
+}
+
 %}
 
 n	[A-Za-z0-9_-]
@@ -82,6 +112,7 @@  n	[A-Za-z0-9_-]
 	int str = 0;
 	int ts, i;
 
+"macro"[ \t].*	handle_macro(yytext + 6);
 [ \t]*#.*\n	|
 [ \t]*\n	{
 	return T_EOL;