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authorMasahiro Yamada <yamada.masahiro@socionext.com>2018-05-28 18:21:49 +0900
committerMasahiro Yamada <yamada.masahiro@socionext.com>2018-05-29 03:31:19 +0900
commit9ced3bddec080e974e910bf887715540a8d9d96b (patch)
tree4bb735afdabb6e4b9dd6f2d607a596fde7b37301 /scripts/kconfig/preprocess.c
parent9de071536c87cb814e210bd762fcf7f645d514a9 (diff)
downloadlinux-stericsson-9ced3bddec080e974e910bf887715540a8d9d96b.tar.gz
kconfig: support user-defined function and recursively expanded variable
Now, we got a basic ability to test compiler capability in Kconfig. config CC_HAS_STACKPROTECTOR def_bool $(shell,($(CC) -Werror -fstack-protector -E -x c /dev/null -o /dev/null 2>/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 that. Hence, here is another feature, user-defined function. This works as a textual shorthand with parameterization. A user-defined function is defined by using the = operator, and can be referenced in the same way as built-in functions. A user-defined function in Make is referenced like $(call my-func,arg1,arg2), but I omitted the 'call' to make the syntax shorter. The definition of a user-defined function contains $(1), $(2), etc. in its body to reference the parameters. It is grammatically valid to pass more or fewer arguments when calling it. We already exploit this feature in our makefiles; scripts/Kbuild.include defines cc-option which takes two arguments at most, but most of the callers pass only one argument. By the way, a variable is supported as a subset of this feature since a variable is "a user-defined function with zero argument". In this context, I mean "variable" as recursively expanded variable. I will add a different flavored variable in the next commit. The code above can be written as follows: [Example Code] success = $(shell,($(1)) >/dev/null 2>&1 && echo y || echo n) cc-option = $(success,$(CC) -Werror $(1) -E -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>
Diffstat (limited to 'scripts/kconfig/preprocess.c')
-rw-r--r--scripts/kconfig/preprocess.c86
1 files changed, 85 insertions, 1 deletions
diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c
index 528be594e1d0..46487fe6b36c 100644
--- a/scripts/kconfig/preprocess.c
+++ b/scripts/kconfig/preprocess.c
@@ -178,6 +178,72 @@ static char *function_expand(const char *name, int argc, char *argv[])
}
/*
+ * Variables (and user-defined functions)
+ */
+static LIST_HEAD(variable_list);
+
+struct variable {
+ char *name;
+ char *value;
+ struct list_head node;
+};
+
+static struct variable *variable_lookup(const char *name)
+{
+ struct variable *v;
+
+ list_for_each_entry(v, &variable_list, node) {
+ if (!strcmp(name, v->name))
+ return v;
+ }
+
+ return NULL;
+}
+
+static char *variable_expand(const char *name, int argc, char *argv[])
+{
+ struct variable *v;
+
+ v = variable_lookup(name);
+ if (!v)
+ return NULL;
+
+ return expand_string_with_args(v->value, argc, argv);
+}
+
+void variable_add(const char *name, const char *value)
+{
+ struct variable *v;
+
+ v = variable_lookup(name);
+ if (v) {
+ free(v->value);
+ } else {
+ v = xmalloc(sizeof(*v));
+ v->name = xstrdup(name);
+ list_add_tail(&v->node, &variable_list);
+ }
+
+ v->value = xstrdup(value);
+}
+
+static void variable_del(struct variable *v)
+{
+ list_del(&v->node);
+ free(v->name);
+ free(v->value);
+ free(v);
+}
+
+void variable_all_del(void)
+{
+ struct variable *v, *tmp;
+
+ list_for_each_entry_safe(v, tmp, &variable_list, node)
+ variable_del(v);
+}
+
+/*
* Evaluate a clause with arguments. argc/argv are arguments from the upper
* function call.
*
@@ -185,14 +251,26 @@ static char *function_expand(const char *name, int argc, char *argv[])
*/
static char *eval_clause(const char *str, size_t len, int argc, char *argv[])
{
- char *tmp, *name, *res, *prev, *p;
+ char *tmp, *name, *res, *endptr, *prev, *p;
int new_argc = 0;
char *new_argv[FUNCTION_MAX_ARGS];
int nest = 0;
int i;
+ unsigned long n;
tmp = xstrndup(str, len);
+ /*
+ * If variable name is '1', '2', etc. It is generally an argument
+ * from a user-function call (i.e. local-scope variable). If not
+ * available, then look-up global-scope variables.
+ */
+ n = strtoul(tmp, &endptr, 10);
+ if (!*endptr && n > 0 && n <= argc) {
+ res = xstrdup(argv[n - 1]);
+ goto free_tmp;
+ }
+
prev = p = tmp;
/*
@@ -238,6 +316,11 @@ static char *eval_clause(const char *str, size_t len, int argc, char *argv[])
new_argv[i] = expand_string_with_args(new_argv[i + 1],
argc, argv);
+ /* Search for variables */
+ res = variable_expand(name, new_argc, new_argv);
+ if (res)
+ goto free;
+
/* Look for built-in functions */
res = function_expand(name, new_argc, new_argv);
if (res)
@@ -255,6 +338,7 @@ free:
for (i = 0; i < new_argc; i++)
free(new_argv[i]);
free(name);
+free_tmp:
free(tmp);
return res;