Refactoring: move UTF-8 decoding functions into coding.h.

json_make_string and json_build_string are generally useful and not
JSON-specific.  Move them to coding.[ch].

* src/coding.h (build_utf8_string): Move from json.c.

* src/coding.c (make_utf8_string): Move from json.c.

* src/json.c (json_make_string, json_build_string): Move to
coding.[ch].  Split out JSON-specific comment.
(json_parse_error, Fjson_serialize, json_to_lisp): Fix callers.

* src/emacs-module.c (module_make_function, module_make_string): Use
new functions.
(module_decode, module_decode_copy): Remove.

1 files changed, 8 insertions, 44 deletions

diff --git a/src/json.c b/src/json.c
index 03468e9f338..cc98914423b 100644
--- a/src/json.c
+++ b/src/json.c
@@ -215,47 +215,11 @@ json_has_suffix (const char *string, const char *suffix)
 
 #endif
 
-/* Create a multibyte Lisp string from the UTF-8 string in
-   [DATA, DATA + SIZE).  If the range [DATA, DATA + SIZE) does not
-   contain a valid UTF-8 string, the returned string will include raw
-   bytes.
-   Note that all callers below either pass only value UTF-8 strings or
-   use this function for formatting error messages; in the latter case
-   correctness isn't critical.  */
-
-static Lisp_Object
-json_make_string (const char *data, ptrdiff_t size)
-{
-  ptrdiff_t chars, bytes;
-  parse_str_as_multibyte ((const unsigned char *) data, size, &chars, &bytes);
-  /* If DATA is a valid UTF-8 string, we can convert it to a Lisp
-     string directly.  Otherwise, we need to decode it.  */
-  if (chars == size || bytes == size)
-    return make_specified_string (data, chars, size, true);
-  else
-    {
-      struct coding_system coding;
-      setup_coding_system (Qutf_8_unix, &coding);
-      coding.mode |= CODING_MODE_LAST_BLOCK;
-      coding.source = (const unsigned char *) data;
-      decode_coding_object (&coding, Qnil, 0, 0, size, size, Qt);
-      return coding.dst_object;
-    }
-}
-
-/* Create a multibyte Lisp string from the NUL-terminated UTF-8
-   string beginning at DATA.  If the string is not a valid UTF-8
-   string, an unspecified string is returned.  Note that all callers
-   below either pass only value UTF-8 strings or use this function for
+/* Note that all callers of make_utf8_string and build_utf8_string
+   below either pass only value UTF-8 strings or use the functionf for
    formatting error messages; in the latter case correctness isn't
    critical.  */
 
-static Lisp_Object
-json_build_string (const char *data)
-{
-  return json_make_string (data, strlen (data));
-}
-
 /* Return a unibyte string containing the sequence of UTF-8 encoding
    units of the UTF-8 representation of STRING.  If STRING does not
    represent a sequence of Unicode scalar values, return a string with
@@ -303,8 +267,8 @@ json_parse_error (const json_error_t *error)
     symbol = Qjson_parse_error;
 #endif
   xsignal (symbol,
-           list5 (json_build_string (error->text),
-                  json_build_string (error->source), INT_TO_INTEGER (error->line),
+           list5 (build_utf8_string (error->text),
+                  build_utf8_string (error->source), INT_TO_INTEGER (error->line),
                   INT_TO_INTEGER (error->column), INT_TO_INTEGER (error->position)));
 }
 
@@ -648,7 +612,7 @@ usage: (json-serialize OBJECT &rest ARGS)  */)
     json_out_of_memory ();
   record_unwind_protect_ptr (json_free, string);
 
-  return unbind_to (count, json_build_string (string));
+  return unbind_to (count, build_utf8_string (string));
 }
 
 struct json_buffer_and_size
@@ -855,7 +819,7 @@ json_to_lisp (json_t *json, struct json_configuration *conf)
     case JSON_REAL:
       return make_float (json_real_value (json));
     case JSON_STRING:
-      return json_make_string (json_string_value (json),
+      return make_utf8_string (json_string_value (json),
                                json_string_length (json));
     case JSON_ARRAY:
       {
@@ -915,7 +879,7 @@ json_to_lisp (json_t *json, struct json_configuration *conf)
               json_t *value;
               json_object_foreach (json, key_str, value)
                 {
-                  Lisp_Object key = json_build_string (key_str);
+                  Lisp_Object key = build_utf8_string (key_str);
                   EMACS_UINT hash;
                   ptrdiff_t i = hash_lookup (h, key, &hash);
                   /* Keys in JSON objects are unique, so the key can't
@@ -932,7 +896,7 @@ json_to_lisp (json_t *json, struct json_configuration *conf)
               json_t *value;
               json_object_foreach (json, key_str, value)
                 {
-                  Lisp_Object key = Fintern (json_build_string (key_str), Qnil);
+                  Lisp_Object key = Fintern (build_utf8_string (key_str), Qnil);
                   result
                     = Fcons (Fcons (key, json_to_lisp (value, conf)),
                              result);