X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fjson.c;h=d26c89ed1c4535183ccf50ce12d328bf4716d29e;hb=142181fcd734a2afff9fe13e54fe51c7a2c824d2;hp=cdcfba598374ba9b59466f8f91764594010107f8;hpb=6e57173fab673b66870b3e181f09542da0d61587;p=openvswitch

diff --git a/lib/json.c b/lib/json.c
index cdcfba59..d26c89ed 100644
--- a/lib/json.c
+++ b/lib/json.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009 Nicira Networks.
+ * Copyright (c) 2009, 2010 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -99,6 +99,9 @@ struct json_parser {
     /* Lexical analysis. */
     enum json_lex_state lex_state;
     struct ds buffer;           /* Buffer for accumulating token text. */
+    int line_number;
+    int column_number;
+    int byte_number;
 
     /* Parsing. */
     enum json_parse_state parse_state;
@@ -219,6 +222,14 @@ json_array_create(struct json **elements, size_t n)
     return json;
 }
 
+struct json *
+json_array_create_1(struct json *elem0)
+{
+    struct json **elems = xmalloc(sizeof *elems);
+    elems[0] = elem0;
+    return json_array_create(elems, 1);
+}
+
 struct json *
 json_array_create_2(struct json *elem0, struct json *elem1)
 {
@@ -266,7 +277,7 @@ json_real_create(double real)
 void
 json_object_put(struct json *json, const char *name, struct json *value)
 {
-    shash_add(json->u.object, name, value);
+    json_destroy(shash_replace(json->u.object, name, value));
 }
 
 void
@@ -595,6 +606,7 @@ json_lex_number(struct json_parser *p)
 {
     const char *cp = ds_cstr(&p->buffer);
     unsigned long long int significand = 0;
+    struct json_token token;
     int sig_digits = 0;
     bool imprecise = false;
     bool negative = false;
@@ -719,7 +731,6 @@ json_lex_number(struct json_parser *p)
             && significand <= (negative
                                ? (unsigned long long int) LLONG_MAX + 1
                                : LLONG_MAX)) {
-            struct json_token token;
             token.type = T_INTEGER;
             token.u.integer = negative ? -significand : significand;
             json_parser_input(p, &token);
@@ -727,152 +738,196 @@ json_lex_number(struct json_parser *p)
         }
     }
 
-    if (pow10 + sig_digits <= DBL_MAX_10_EXP) {
-        struct json_token token;
-        token.type = T_REAL;
-        token.u.real = significand * pow(10.0, pow10);
-        if (token.u.real <= DBL_MAX) {
-            if (negative && token.u.real) {
-                token.u.real = -token.u.real;
-            }
-            json_parser_input(p, &token);
-            return;
-        }
+    token.type = T_REAL;
+    if (!str_to_double(ds_cstr(&p->buffer), &token.u.real)) {
+        json_error(p, "number outside valid range");
+        return;
+    }
+    /* Suppress negative zero. */
+    if (token.u.real == 0) {
+        token.u.real = 0;
     }
-    json_error(p, "number outside valid range");
+    json_parser_input(p, &token);
 }
 
-static bool
-json_lex_4hex(struct json_parser *p, const char *cp, int *valuep)
+static const char *
+json_lex_4hex(const char *cp, const char *end, int *valuep)
 {
     int value, i;
 
+    if (cp + 4 > end) {
+        return "quoted string ends within \\u escape";
+    }
+
     value = 0;
     for (i = 0; i < 4; i++) {
         unsigned char c = *cp++;
         if (!isxdigit(c)) {
-            json_error(p, "malformed \\u escape");
-            return false;
+            return "malformed \\u escape";
         }
         value = (value << 4) | hexit_value(c);
     }
     if (!value) {
-        json_error(p, "null bytes not supported in quoted strings");
-        return false;
+        return "null bytes not supported in quoted strings";
     }
     *valuep = value;
-    return true;
+    return NULL;
 }
 
 static const char *
-json_lex_unicode(struct json_parser *p, const char *cp, struct ds *s)
+json_lex_unicode(const char *cp, const char *end, struct ds *out)
 {
+    const char *error;
     int c0, c1;
 
-    if (!json_lex_4hex(p, cp, &c0)) {
+    error = json_lex_4hex(cp, end, &c0);
+    if (error) {
+        ds_clear(out);
+        ds_put_cstr(out, error);
         return NULL;
     }
     cp += 4;
     if (!uc_is_leading_surrogate(c0)) {
-        ds_put_utf8(s, c0);
+        ds_put_utf8(out, c0);
         return cp;
     }
 
-    if (*cp++ != '\\' || *cp++ != 'u') {
-        json_error(p, "malformed escaped surrogate pair");
+    if (cp + 2 > end || *cp++ != '\\' || *cp++ != 'u') {
+        ds_clear(out);
+        ds_put_cstr(out, "malformed escaped surrogate pair");
         return NULL;
     }
 
-    if (!json_lex_4hex(p, cp, &c1)) {
+    error = json_lex_4hex(cp, end, &c1);
+    if (error) {
+        ds_clear(out);
+        ds_put_cstr(out, error);
         return NULL;
     }
     cp += 4;
     if (!uc_is_trailing_surrogate(c1)) {
-        json_error(p, "second half of escaped surrogate pair is not "
-                   "trailing surrogate");
+        ds_clear(out);
+        ds_put_cstr(out, "second half of escaped surrogate pair is not "
+                    "trailing surrogate");
         return NULL;
     }
 
-    ds_put_utf8(s, utf16_decode_surrogate_pair(c0, c1));
+    ds_put_utf8(out, utf16_decode_surrogate_pair(c0, c1));
     return cp;
 }
 
-static void
-json_lex_string(struct json_parser *p)
+bool
+json_string_unescape(const char *in, size_t in_len, char **outp)
 {
-    struct json_token token;
-    const char *cp;
-    struct ds s;
+    const char *end = in + in_len;
+    bool ok = false;
+    struct ds out;
 
-    cp = ds_cstr(&p->buffer);
-    if (!strchr(cp, '\\')) {
-        token.type = T_STRING;
-        token.u.string = cp;
-        json_parser_input(p, &token);
-        return;
+    ds_init(&out);
+    ds_reserve(&out, in_len);
+    if (in_len > 0 && in[in_len - 1] == '\\') {
+        ds_put_cstr(&out, "quoted string may not end with backslash");
+        goto exit;
     }
-
-    ds_init(&s);
-    ds_reserve(&s, strlen(cp));
-    while (*cp != '\0') {
-        if (*cp != '\\') {
-            ds_put_char(&s, *cp++);
+    while (in < end) {
+        if (*in == '"') {
+            ds_clear(&out);
+            ds_put_cstr(&out, "quoted string may not include unescaped \"");
+            goto exit;
+        }
+        if (*in != '\\') {
+            ds_put_char(&out, *in++);
             continue;
         }
 
-        cp++;
-        switch (*cp++) {
+        in++;
+        switch (*in++) {
         case '"': case '\\': case '/':
-            ds_put_char(&s, cp[-1]);
+            ds_put_char(&out, in[-1]);
             break;
 
         case 'b':
-            ds_put_char(&s, '\b');
+            ds_put_char(&out, '\b');
             break;
 
         case 'f':
-            ds_put_char(&s, '\f');
+            ds_put_char(&out, '\f');
             break;
 
         case 'n':
-            ds_put_char(&s, '\n');
+            ds_put_char(&out, '\n');
             break;
 
         case 'r':
-            ds_put_char(&s, '\r');
+            ds_put_char(&out, '\r');
             break;
 
         case 't':
-            ds_put_char(&s, '\t');
+            ds_put_char(&out, '\t');
             break;
 
         case 'u':
-            cp = json_lex_unicode(p, cp, &s);
-            if (!cp) {
+            in = json_lex_unicode(in, end, &out);
+            if (!in) {
                 goto exit;
             }
             break;
 
         default:
-            json_error(p, "bad escape \\%c", cp[-1]);
+            ds_clear(&out);
+            ds_put_format(&out, "bad escape \\%c", in[-1]);
             goto exit;
         }
     }
+    ok = true;
+
+exit:
+    *outp = ds_cstr(&out);
+    return ok;
+}
+
+static void
+json_parser_input_string(struct json_parser *p, const char *s)
+{
+    struct json_token token;
 
     token.type = T_STRING;
-    token.u.string = ds_cstr(&s);
+    token.u.string = s;
     json_parser_input(p, &token);
+}
 
-exit:
-    ds_destroy(&s);
-    return;
+static void
+json_lex_string(struct json_parser *p)
+{
+    const char *raw = ds_cstr(&p->buffer);
+    if (!strchr(raw, '\\')) {
+        json_parser_input_string(p, raw);
+    } else {
+        char *cooked;
+
+        if (json_string_unescape(raw, strlen(raw), &cooked)) {
+            json_parser_input_string(p, cooked);
+        } else {
+            json_error(p, "%s", cooked);
+        }
+
+        free(cooked);
+    }
 }
 
 static bool
-json_lex_input(struct json_parser *p, int c)
+json_lex_input(struct json_parser *p, unsigned char c)
 {
     struct json_token token;
 
+    p->byte_number++;
+    if (c == '\n') {
+        p->column_number = 0;
+        p->line_number++;
+    } else {
+        p->column_number++;
+    }
+
     switch (p->lex_state) {
     case JSON_LEX_START:
         switch (c) {
@@ -986,18 +1041,34 @@ json_from_string(const char *string)
 struct json *
 json_from_file(const char *file_name)
 {
-    struct json_parser *p;
     struct json *json;
     FILE *stream;
 
-    /* Open file. */
     stream = fopen(file_name, "r");
     if (!stream) {
         return json_string_create_nocopy(
             xasprintf("error opening \"%s\": %s", file_name, strerror(errno)));
     }
+    json = json_from_stream(stream);
+    fclose(stream);
+
+    return json;
+}
+
+/* Parses the contents of 'stream' as a JSON object or array, and returns a
+ * newly allocated 'struct json'.  The caller must free the returned structure
+ * with json_destroy() when it is no longer needed.
+ *
+ * The file must be encoded in UTF-8.
+ *
+ * See json_from_string() for return value semantics.
+ */
+struct json *
+json_from_stream(FILE *stream)
+{
+    struct json_parser *p;
+    struct json *json;
 
-    /* Read and parse file. */
     p = json_parser_create(JSPF_TRAILER);
     for (;;) {
         char buffer[BUFSIZ];
@@ -1010,13 +1081,11 @@ json_from_file(const char *file_name)
     }
     json = json_parser_finish(p);
 
-    /* Close file and check for I/O errors. */
     if (ferror(stream)) {
         json_destroy(json);
         json = json_string_create_nocopy(
-            xasprintf("error reading \"%s\": %s", file_name, strerror(errno)));
+            xasprintf("error reading JSON stream: %s", strerror(errno)));
     }
-    fclose(stream);
 
     return json;
 }
@@ -1144,6 +1213,7 @@ json_parser_push(struct json_parser *p,
         p->parse_state = new_state;
         return node;
     } else {
+        json_destroy(new_json);
         json_error(p, "input exceeds maximum nesting depth %d",
                    JSON_MAX_HEIGHT);
         return NULL;
@@ -1340,12 +1410,18 @@ static void
 json_error(struct json_parser *p, const char *format, ...)
 {
     if (!p->error) {
+        struct ds msg;
         va_list args;
 
+        ds_init(&msg);
+        ds_put_format(&msg, "line %d, column %d, byte %d: ",
+                      p->line_number, p->column_number, p->byte_number);
         va_start(args, format);
-        p->error = xvasprintf(format, args);
+        ds_put_format_valist(&msg, format, args);
         va_end(args);
 
+        p->error = ds_steal_cstr(&msg);
+
         p->done = true;
     }
 }
@@ -1353,17 +1429,17 @@ json_error(struct json_parser *p, const char *format, ...)
 #define SPACES_PER_LEVEL 2
 
 struct json_serializer {
-    struct ds ds;
+    struct ds *ds;
     int depth;
     int flags;
 };
 
-static void json_to_ds(const struct json *, struct json_serializer *);
-static void json_object_to_ds(const struct shash *object,
-                              struct json_serializer *);
-static void json_array_to_ds(const struct json_array *,
-                             struct json_serializer *);
-static void json_string_to_ds(const char *string, struct ds *);
+static void json_serialize(const struct json *, struct json_serializer *);
+static void json_serialize_object(const struct shash *object,
+                                  struct json_serializer *);
+static void json_serialize_array(const struct json_array *,
+                                 struct json_serializer *);
+static void json_serialize_string(const char *, struct ds *);
 
 /* Converts 'json' to a string in JSON format, encoded in UTF-8, and returns
  * that string.  The caller is responsible for freeing the returned string,
@@ -1381,19 +1457,30 @@ static void json_string_to_ds(const char *string, struct ds *);
  * object, since a bare literal does not satisfy the JSON grammar. */
 char *
 json_to_string(const struct json *json, int flags)
+{
+    struct ds ds;
+
+    ds_init(&ds);
+    json_to_ds(json, flags, &ds);
+    return ds_steal_cstr(&ds);
+}
+
+/* Same as json_to_string(), but the output is appended to 'ds'. */
+void
+json_to_ds(const struct json *json, int flags, struct ds *ds)
 {
     struct json_serializer s;
-    ds_init(&s.ds);
+
+    s.ds = ds;
     s.depth = 0;
     s.flags = flags;
-    json_to_ds(json, &s);
-    return ds_steal_cstr(&s.ds);
+    json_serialize(json, &s);
 }
 
 static void
-json_to_ds(const struct json *json, struct json_serializer *s)
+json_serialize(const struct json *json, struct json_serializer *s)
 {
-    struct ds *ds = &s->ds;
+    struct ds *ds = s->ds;
 
     switch (json->type) {
     case JSON_NULL:
@@ -1409,11 +1496,11 @@ json_to_ds(const struct json *json, struct json_serializer *s)
         break;
 
     case JSON_OBJECT:
-        json_object_to_ds(json->u.object, s);
+        json_serialize_object(json->u.object, s);
         break;
 
     case JSON_ARRAY:
-        json_array_to_ds(&json->u.array, s);
+        json_serialize_array(&json->u.array, s);
         break;
 
     case JSON_INTEGER:
@@ -1425,7 +1512,7 @@ json_to_ds(const struct json *json, struct json_serializer *s)
         break;
 
     case JSON_STRING:
-        json_string_to_ds(json->u.string, ds);
+        json_serialize_string(json->u.string, ds);
         break;
 
     case JSON_N_TYPES:
@@ -1438,34 +1525,34 @@ static void
 indent_line(struct json_serializer *s)
 {
     if (s->flags & JSSF_PRETTY) {
-        ds_put_char(&s->ds, '\n');
-        ds_put_char_multiple(&s->ds, ' ', SPACES_PER_LEVEL * s->depth);
+        ds_put_char(s->ds, '\n');
+        ds_put_char_multiple(s->ds, ' ', SPACES_PER_LEVEL * s->depth);
     }
 }
 
 static void
-json_object_member_to_ds(size_t i, const struct shash_node *node,
-                         struct json_serializer *s)
+json_serialize_object_member(size_t i, const struct shash_node *node,
+                             struct json_serializer *s)
 {
-    struct ds *ds = &s->ds;
+    struct ds *ds = s->ds;
 
     if (i) {
         ds_put_char(ds, ',');
         indent_line(s);
     }
 
-    json_string_to_ds(node->name, ds);
+    json_serialize_string(node->name, ds);
     ds_put_char(ds, ':');
     if (s->flags & JSSF_PRETTY) {
         ds_put_char(ds, ' ');
     }
-    json_to_ds(node->data, s);
+    json_serialize(node->data, s);
 }
 
 static void
-json_object_to_ds(const struct shash *object, struct json_serializer *s)
+json_serialize_object(const struct shash *object, struct json_serializer *s)
 {
-    struct ds *ds = &s->ds;
+    struct ds *ds = s->ds;
 
     ds_put_char(ds, '{');
 
@@ -1479,7 +1566,7 @@ json_object_to_ds(const struct shash *object, struct json_serializer *s)
         nodes = shash_sort(object);
         n = shash_count(object);
         for (i = 0; i < n; i++) {
-            json_object_member_to_ds(i, nodes[i], s);
+            json_serialize_object_member(i, nodes[i], s);
         }
         free(nodes);
     } else {
@@ -1488,7 +1575,7 @@ json_object_to_ds(const struct shash *object, struct json_serializer *s)
 
         i = 0;
         SHASH_FOR_EACH (node, object) {
-            json_object_member_to_ds(i++, node, s);
+            json_serialize_object_member(i++, node, s);
         }
     }
 
@@ -1497,9 +1584,9 @@ json_object_to_ds(const struct shash *object, struct json_serializer *s)
 }
 
 static void
-json_array_to_ds(const struct json_array *array, struct json_serializer *s)
+json_serialize_array(const struct json_array *array, struct json_serializer *s)
 {
-    struct ds *ds = &s->ds;
+    struct ds *ds = s->ds;
     size_t i;
 
     ds_put_char(ds, '[');
@@ -1513,7 +1600,7 @@ json_array_to_ds(const struct json_array *array, struct json_serializer *s)
                 ds_put_char(ds, ',');
                 indent_line(s);
             }
-            json_to_ds(array->elems[i], s);
+            json_serialize(array->elems[i], s);
         }
     }
 
@@ -1522,7 +1609,7 @@ json_array_to_ds(const struct json_array *array, struct json_serializer *s)
 }
 
 static void
-json_string_to_ds(const char *string, struct ds *ds)
+json_serialize_string(const char *string, struct ds *ds)
 {
     uint8_t c;