kconfig: split out code touching a file to conf_touch_dep()

conf_touch_deps() iterates over symbols, touching corresponding
include/config/*.h files as needed.

Split the part that touches a single file into a new helper so it can
be reused.

The new helper, conf_touch_dep(), takes a symbol name as a parameter,
and touches the corresponding include/config/*.h file.

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

1 files changed, 49 insertions, 43 deletions

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 4c76d561d383..39dfe463de15 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -74,6 +74,47 @@ static int make_parent_dir(const char *path)
         return 0;
 }
 
+static char depfile_path[PATH_MAX];
+static size_t depfile_prefix_len;
+
+/* touch depfile for symbol 'name' */
+static int conf_touch_dep(const char *name)
+{
+        int fd, ret;
+        const char *s;
+        char *d, c;
+
+        /* check overflow: prefix + name + ".h" + '\0' must fit in buffer. */
+        if (depfile_prefix_len + strlen(name) + 3 > sizeof(depfile_path))
+                return -1;
+
+        d = depfile_path + depfile_prefix_len;
+        s = name;
+
+        while ((c = *s++))
+                *d++ = (c == '_') ? '/' : tolower(c);
+        strcpy(d, ".h");
+
+        /* Assume directory path already exists. */
+        fd = open(depfile_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+        if (fd == -1) {
+                if (errno != ENOENT)
+                        return -1;
+
+                ret = make_parent_dir(depfile_path);
+                if (ret)
+                        return ret;
+
+                /* Try it again. */
+                fd = open(depfile_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+                if (fd == -1)
+                        return -1;
+        }
+        close(fd);
+
+        return 0;
+}
+
 struct conf_printer {
         void (*print_symbol)(FILE *, struct symbol *, const char *, void *);
         void (*print_comment)(FILE *, const char *, void *);
@@ -909,21 +950,16 @@ static int conf_write_dep(const char *name)
 static int conf_touch_deps(void)
 {
         const char *name;
-        char path[PATH_MAX+1];
-        char *s, *d, c;
         struct symbol *sym;
-        int res, i, fd;
+        int res, i;
+
+        strcpy(depfile_path, "include/config/");
+        depfile_prefix_len = strlen(depfile_path);
 
         name = conf_get_autoconfig_name();
         conf_read_simple(name, S_DEF_AUTO);
         sym_calc_value(modules_sym);
 
-        if (make_parent_dir("include/config/foo.h"))
-                return 1;
-        if (chdir("include/config"))
-                return 1;
-
-        res = 0;
         for_all_symbols(i, sym) {
                 sym_calc_value(sym);
                 if ((sym->flags & SYMBOL_NO_WRITE) || !sym->name)
@@ -975,42 +1011,12 @@ static int conf_touch_deps(void)
                  *      different from 'no').
                  */
 
-                /* Replace all '_' and append ".h" */
-                s = sym->name;
-                d = path;
-                while ((c = *s++)) {
-                        c = tolower(c);
-                        *d++ = (c == '_') ? '/' : c;
-                }
-                strcpy(d, ".h");
-
-                /* Assume directory path already exists. */
-                fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-                if (fd == -1) {
-                        if (errno != ENOENT) {
-                                res = 1;
-                                break;
-                        }
-
-                        if (make_parent_dir(path)) {
-                                res = 1;
-                                goto out;
-                        }
-
-                        /* Try it again. */
-                        fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-                        if (fd == -1) {
-                                res = 1;
-                                break;
-                        }
-                }
-                close(fd);
+                res = conf_touch_dep(sym->name);
+                if (res)
+                        return res;
         }
-out:
-        if (chdir("../.."))
-                return 1;
 
-        return res;
+        return 0;
 }
 
 int conf_write_autoconf(int overwrite)