kconfig: add module_name shortcut

From: Alexey Dobriyan <[email protected]>

As correctly noticed in bug 11446
(http://bugzilla.kernel.org/show_bug.cgi?id=11446) "To compile this driver as a module, blah-blah" boilerplate is being copy-pasted to death with slight variations.

Add Kconfig token "module_name" to supply module's name. Example:

	config FOO
		tristate "foo"
		module_name foo
		---help---
		  foo

Print module's name as following on menuconfigs help screen (press 'h'):

Module name: foo

8139too driver converted to show real-life example.

P.S.: menuconfig only, no checking wrt modular/standalone code et al.

---

 drivers/net/Kconfig                  |    4 
 scripts/kconfig/expr.h               |    4 
 scripts/kconfig/lkc.h                |    1 
 scripts/kconfig/mconf.c              |    2 
 scripts/kconfig/menu.c               |    8 
 scripts/kconfig/symbol.c             |    2 
 scripts/kconfig/zconf.gperf          |    1 
 scripts/kconfig/zconf.hash.c_shipped |  184 ++++----
 scripts/kconfig/zconf.tab.c_shipped  |  539 ++++++++++++-------------
 scripts/kconfig/zconf.y              |   12 
 10 files changed, 404 insertions(+), 353 deletions(-)

diff -puN drivers/net/Kconfig~kconfig-add-module_name-shortcut drivers/net/Kconfig
@@ -1551,14 +1551,12 @@ config 8139TOO
 	depends on NET_PCI && PCI
 	select CRC32
 	select MII
+	module_name 8139too
 	---help---
 	  This is a driver for the Fast Ethernet PCI network cards based on
 	  the RTL 8129/8130/8139 chips. If you have one of those, say Y and
 	  read the Ethernet-HOWTO <http://www.tldp.org/docs.html#howto>.
 
-	  To compile this driver as a module, choose M here: the module
-	  will be called 8139too.  This is recommended.
-
 config 8139TOO_PIO
 	bool "Use PIO instead of MMIO"
 	default y

diff -puN scripts/kconfig/expr.h~kconfig-add-module_name-shortcut scripts/kconfig/expr.h
@@ -107,7 +107,8 @@ struct symbol {
 
 enum prop_type {
 	P_UNKNOWN, P_PROMPT, P_COMMENT, P_MENU, P_DEFAULT, P_CHOICE,
-	P_SELECT, P_RANGE, P_ENV
+	P_SELECT, P_RANGE, P_ENV,
+	P_MODULE_NAME,
 };
 
 struct property {

@@ -115,6 +116,7 @@ struct property {
 	struct symbol *sym;
 	enum prop_type type;
 	const char *text;
+	char *module_name;
 	struct expr_value visible;
 	struct expr *expr;
 	struct menu *menu;

diff -puN scripts/kconfig/lkc.h~kconfig-add-module_name-shortcut scripts/kconfig/lkc.h
@@ -95,6 +95,7 @@ struct property *menu_add_prompt(enum pr
 void menu_add_expr(enum prop_type type, struct expr *expr, struct expr *dep);
 void menu_add_symbol(enum prop_type type, struct symbol *sym, struct expr *dep);
 void menu_add_option(int token, char *arg);
+void menu_add_module_name(char *module_name);
 void menu_finalize(struct menu *parent);
 void menu_set_type(int type);
 

diff -puN scripts/kconfig/mconf.c~kconfig-add-module_name-shortcut scripts/kconfig/mconf.c
@@ -320,6 +320,8 @@ static void get_symbol_str(struct gstr *
 	bool hit;
 	struct property *prop;
 
+	for_all_properties(sym, prop, P_MODULE_NAME)
+		str_printf(r, _("Module name: %s\n\n"), prop->module_name);
 	if (sym && sym->name)
 		str_printf(r, "Symbol: %s [=%s]\n", sym->name,
 		                                    sym_get_string_value(sym));

diff -puN scripts/kconfig/menu.c~kconfig-add-module_name-shortcut scripts/kconfig/menu.c
@@ -178,6 +178,14 @@ void menu_add_option(int token, char *ar
 	}
 }
 
+void menu_add_module_name(char *module_name)
+{
+	struct property *prop;
+
+	prop = prop_alloc(P_MODULE_NAME, current_entry->sym);
+	prop->module_name = strdup(module_name);
+}
+
 static int menu_range_valid_sym(struct symbol *sym, struct symbol *sym2)
 {
 	return sym2->type == S_INT || sym2->type == S_HEX ||

diff -puN scripts/kconfig/symbol.c~kconfig-add-module_name-shortcut scripts/kconfig/symbol.c
@@ -937,6 +937,8 @@ const char *prop_get_type_name(enum prop
 		return "select";
 	case P_RANGE:
 		return "range";
+	case P_MODULE_NAME:
+		return "module_name";
 	case P_UNKNOWN:
 		break;
 	}

diff -puN scripts/kconfig/zconf.gperf~kconfig-add-module_name-shortcut scripts/kconfig/zconf.gperf
@@ -41,4 +41,5 @@ on,		T_ON,		TF_PARAM
 modules,	T_OPT_MODULES,	TF_OPTION
 defconfig_list,	T_OPT_DEFCONFIG_LIST,TF_OPTION
 env,		T_OPT_ENV,	TF_OPTION
+module_name,	T_MODULE_NAME,	TF_COMMAND
 %%

diff -puN scripts/kconfig/zconf.y~kconfig-add-module_name-shortcut scripts/kconfig/zconf.y
@@ -72,6 +72,7 @@ static struct menu *current_menu, *curre
 %token <id>T_RANGE
 %token <id>T_OPTION
 %token <id>T_ON
+%token <id>T_MODULE_NAME
 %token <string> T_WORD
 %token <string> T_WORD_QUOTE
 %token T_UNEQUAL

@@ -90,6 +91,7 @@ static struct menu *current_menu, *curre
 %type <expr> if_expr
 %type <id> end
 %type <id> option_name
+%type <string> module_name
 %type <menu> if_entry menu_entry choice_entry
 %type <string> symbol_option_arg word_opt
 

@@ -217,6 +219,12 @@ config_option: T_RANGE symbol symbol if_
 	printd(DEBUG_PARSE, "%s:%d:range\n", zconf_curname(), zconf_lineno());
 };
 
+config_option: T_MODULE_NAME module_name T_EOL
+{
+	menu_add_module_name($2);
+	printd(DEBUG_PARSE, "%s:%d:module_name\n", zconf_curname(), zconf_lineno());
+};
+
 symbol_option: T_OPTION symbol_option_list T_EOL
 ;
 

@@ -461,6 +469,10 @@ symbol:	  T_WORD	{ $$ = sym_lookup($1, 0
 
 word_opt: /* empty */			{ $$ = NULL; }
 	| T_WORD
+;
+
+module_name:	T_WORD	{ $$ = $1 }
+;
 
 %%
 

_

Hi,

This syntax is a little inflexible.
Below is a patch, which integrates modules fully into the kconfig syntax, so this is enough:

module foo
tristate "foo"

The config symbol is derived from the module name or can be specified after the name. I also added the option to specify the sources, so that these can be used to generate the Kbuild information.
As a bonus feature the behaviour of boolean modules regarding their dependencies is a little different, so that the module is only visible when all its dependencies are builtin.

I didn't modify the help text, but it short quite simply to do on top of this patch.

	menu_add_symbol(P_MODULE, sym_lookup($2, SYMBOL_CONST), NULL);

---
 Documentation/kbuild/kconfig-language.txt |   18 
 scripts/kconfig/expr.h                    |    3 
 scripts/kconfig/menu.c                    |    2 
 scripts/kconfig/qconf.cc                  |    2 
 scripts/kconfig/symbol.c                  |    4 
 scripts/kconfig/zconf.gperf               |    2 
 scripts/kconfig/zconf.hash.c_shipped      |  187 ++++---
 scripts/kconfig/zconf.tab.c_shipped       |  714 ++++++++++++++++--------------
 scripts/kconfig/zconf.y                   |   61 ++
 9 files changed, 587 insertions(+), 406 deletions(-)

Index: linux-2.6/Documentation/kbuild/kconfig-language.txt
===================================================================
@@ -150,6 +150,10 @@ applicable everywhere (see syntax).
     to the build environment (if this is desired, it can be done via
     another symbol).
 
+- sources: "source" <name> ... ["if" <expr>]
+  This is only valid for modules and allows to specify the source files
+  to be used for building the module.
+
 Menu dependencies
 -----------------
 

@@ -243,6 +247,7 @@ line starts with a keyword (except help 
 end a menu entry:
 - config
 - menuconfig
+- module
 - choice/endchoice
 - comment
 - menu/endmenu

@@ -266,6 +271,19 @@ This is similar to the simple config ent
 hint to front ends, that all suboptions should be displayed as a
 separate list of options.
 
+module:
+	"module" <name> [<symbol>]
+	<module options>
+
+This is similiar to a normal config option, but allows to specify
+additional information, which are used to build modules. The config
+symbol is optional and it's generated from the module name by
+capitalizing it.
+There is an important difference for boolean modules, their dependencies
+are modified so that the module is only visible when all it's
+dependencies are 'y' (i.e. builtin) unlike other boolean config option,
+which are when it's dependecies are not 'n'.
+
 choices:
 
 	"choice"

Index: linux-2.6/scripts/kconfig/expr.h
===================================================================
@@ -88,6 +88,7 @@ struct symbol {
 #define SYMBOL_CHECK		0x0008
 #define SYMBOL_CHOICE		0x0010
 #define SYMBOL_CHOICEVAL	0x0020
+#define SYMBOL_MODULE		0x0040
 #define SYMBOL_VALID		0x0080
 #define SYMBOL_OPTIONAL		0x0100
 #define SYMBOL_WRITE		0x0200

@@ -107,7 +108,7 @@ struct symbol {
 
 enum prop_type {
 	P_UNKNOWN, P_PROMPT, P_COMMENT, P_MENU, P_DEFAULT, P_CHOICE,
-	P_SELECT, P_RANGE, P_ENV
+	P_SELECT, P_RANGE, P_ENV, P_MODULE, P_SOURCES
 };
 
 struct property {

Index: linux-2.6/scripts/kconfig/menu.c
===================================================================
@@ -272,6 +272,8 @@ void menu_finalize(struct menu *parent)
 				dep = expr_transform(prop->visible.expr);
 				dep = expr_alloc_and(expr_copy(basedep), dep);
 				dep = expr_eliminate_dups(dep);
+				if (menu->sym && (menu->sym->flags & SYMBOL_MODULE))
+					dep = expr_trans_compare(dep, E_EQUAL, &symbol_yes);
 				if (menu->sym && menu->sym->type != S_TRISTATE)
 					dep = expr_trans_bool(dep);
 				prop->visible.expr = dep;

Index: linux-2.6/scripts/kconfig/qconf.cc
===================================================================
@@ -1091,6 +1091,8 @@ QString ConfigInfoView::debug_info(struc
 		case P_SELECT:
 		case P_RANGE:
 		case P_ENV:
+		case P_MODULE:
+		case P_SOURCES:
 			debug += prop_get_type_name(prop->type);
 			debug += ": ";
 			expr_print(prop->expr, expr_print_help, &debug, E_NONE);

Index: linux-2.6/scripts/kconfig/symbol.c
===================================================================
@@ -937,6 +937,10 @@ const char *prop_get_type_name(enum prop
 		return "select";
 	case P_RANGE:
 		return "range";
+	case P_MODULE:
+		return "module";
+	case P_SOURCES:
+		return "sources";
 	case P_UNKNOWN:
 		break;
 	}

Index: linux-2.6/scripts/kconfig/zconf.gperf
===================================================================
@@ -19,6 +19,7 @@ endchoice,	T_ENDCHOICE,	TF_COMMAND
 comment,	T_COMMENT,	TF_COMMAND
 config,		T_CONFIG,	TF_COMMAND
 menuconfig,	T_MENUCONFIG,	TF_COMMAND
+module,		T_MODULE,	TF_COMMAND
 help,		T_HELP,		TF_COMMAND
 if,		T_IF,		TF_COMMAND|TF_PARAM
 endif,		T_ENDIF,	TF_COMMAND

@@ -37,6 +38,7 @@ string,		T_TYPE,		TF_COMMAND, S_STRING
 select,		T_SELECT,	TF_COMMAND
 range,		T_RANGE,	TF_COMMAND
 option,		T_OPTION,	TF_COMMAND
+sources,	T_SOURCES,	TF_COMMAND
 on,		T_ON,		TF_PARAM
 modules,	T_OPT_MODULES,	TF_OPTION
 defconfig_list,	T_OPT_DEFCONFIG_LIST,TF_OPTION

Thanks Roman - looks good.

Do you have any idea how do do this properly on the Kbuild side? I see a few possibilities but have not made up my mind yet.

1) We could generate a Kbuild.foo file in the dir where we have the module
2) We could add info to auto.conf so we could build all modules defined in the configuration in one step

Both alternatives have their drawbacks.

I hesitate to add the patch until we have the kbuild bits sorted out. I do not ask you to do the kbuild bits - I'm just asking for inputs on what you have considered when you made this patch.

Have you ever considered the possibility to add the Kconfig info direct in the .c file so we could have a single file driver for the typical cases?
It could be a natural extension to what you made so far.

Sam

Hi,

I'm considering a combination of both.
Separate files keeps thing local, as we may need further Makefile fragments, so keeping things local reduces the risk of conflicts. OTOH we should have a global list of all dirs, which is then used by make, this avoids the dependency problem of some old generated Makefile still around which is magically included.

I think currently it would create more problem than it provides in convenience.
First you have the dependency problem. How do you find new files? What happens if there are multiple version of a driver (e.g. a backup file). Then there will be a performance problem, so that we would need some caching. Currently the whole Kconfig is read, when something is changed, since it's a only few MB, we get away with with, but if you have to scan all the sources it's a problem.

bye, Roman