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Subject[PATCH v4 13/31] kconfig: support append assignment operator
Date
Support += operator.  This appends a space and the text on the
righthand side to a variable.

The timing of the evaluation of the righthand side depends on the
flavor of the variable. If the lefthand side was originally defined
as a simple variable, the righthand side is expanded immediately.
Otherwise, the expansion is deferred. Appending something to an
undefined variable results in a recursive variable.

To implement this, we need to remember the flavor of variables.

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

Changes in v4: None
Changes in v3:
- newly added

Changes in v2: None

scripts/kconfig/lkc_proto.h | 1 +
scripts/kconfig/preprocess.c | 29 +++++++++++++++++++++++++++--
scripts/kconfig/zconf.l | 1 +
3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/scripts/kconfig/lkc_proto.h b/scripts/kconfig/lkc_proto.h
index 6303193..a8b7a33 100644
--- a/scripts/kconfig/lkc_proto.h
+++ b/scripts/kconfig/lkc_proto.h
@@ -52,6 +52,7 @@ const char * prop_get_type_name(enum prop_type type);
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,
diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c
index 5d7bd9d..47b32dc 100644
--- a/scripts/kconfig/preprocess.c
+++ b/scripts/kconfig/preprocess.c
@@ -208,6 +208,7 @@ static LIST_HEAD(variable_list);
struct variable {
char *name;
char *value;
+ enum variable_flavor flavor;
struct list_head node;
};

@@ -250,18 +251,42 @@ void variable_add(const char *name, const char *value,
enum variable_flavor flavor)
{
struct variable *v;
+ char *new_value;
+ bool append = false;

v = variable_lookup(name);
if (v) {
- free(v->value);
+ /* For defined variables, += inherits the existing flavor */
+ if (flavor == VAR_APPEND) {
+ flavor = v->flavor;
+ append = true;
+ } else {
+ free(v->value);
+ }
} else {
+ /* For undefined variables, += assumes the recursive flavor */
+ if (flavor == VAR_APPEND)
+ flavor = VAR_RECURSIVE;
+
v = xmalloc(sizeof(*v));
v->name = xstrdup(name);
list_add_tail(&v->node, &variable_list);
}

- v->value = (flavor == VAR_SIMPLE) ? expand_string(value) :
+ v->flavor = flavor;
+
+ new_value = (flavor == VAR_SIMPLE) ? expand_string(value) :
xstrdup(value);
+
+ if (append) {
+ v->value = xrealloc(v->value,
+ strlen(v->value) + strlen(new_value) + 2);
+ strcat(v->value, " ");
+ strcat(v->value, new_value);
+ free(new_value);
+ } else {
+ v->value = new_value;
+ }
}

static void variable_del(struct variable *v)
diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
index aa76942..c68ca56b 100644
--- a/scripts/kconfig/zconf.l
+++ b/scripts/kconfig/zconf.l
@@ -116,6 +116,7 @@ n [A-Za-z0-9_-]
}
"=" { BEGIN(ASSIGN_VAL); yylval.flavor = VAR_RECURSIVE; return T_ASSIGN; }
":=" { BEGIN(ASSIGN_VAL); yylval.flavor = VAR_SIMPLE; return T_ASSIGN; }
+ "+=" { BEGIN(ASSIGN_VAL); yylval.flavor = VAR_APPEND; return T_ASSIGN; }
[[:blank:]]+
. warn_ignored_character(*yytext);
\n {
--
2.7.4
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