qapi: New parse_qapi_name()

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488317230-26248-19-git-send-email-armbru@redhat.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/qapi/qapi-util.c b/qapi/qapi-util.c
index 818730a660..e28dbd0ac3 100644
--- a/qapi/qapi-util.c
+++ b/qapi/qapi-util.c
@@ -33,3 +33,50 @@ int qapi_enum_parse(const char * const lookup[], const char *buf,
     error_setg(errp, "invalid parameter value: %s", buf);
     return def;
 }
+
+/*
+ * Parse a valid QAPI name from @str.
+ * A valid name consists of letters, digits, hyphen and underscore.
+ * It may be prefixed by __RFQDN_ (downstream extension), where RFQDN
+ * may contain only letters, digits, hyphen and period.
+ * The special exception for enumeration names is not implemented.
+ * See docs/qapi-code-gen.txt for more on QAPI naming rules.
+ * Keep this consistent with scripts/qapi.py!
+ * If @complete, the parse fails unless it consumes @str completely.
+ * Return its length on success, -1 on failure.
+ */
+int parse_qapi_name(const char *str, bool complete)
+{
+    const char *p = str;
+
+    if (*p == '_') {            /* Downstream __RFQDN_ */
+        p++;
+        if (*p != '_') {
+            return -1;
+        }
+        while (*++p) {
+            if (!qemu_isalnum(*p) && *p != '-' && *p != '.') {
+                break;
+            }
+        }
+
+        if (*p != '_') {
+            return -1;
+        }
+        p++;
+    }
+
+    if (!qemu_isalpha(*p)) {
+        return -1;
+    }
+    while (*++p) {
+        if (!qemu_isalnum(*p) && *p != '-' && *p != '_') {
+            break;
+        }
+    }
+
+    if (complete && *p) {
+        return -1;
+    }
+    return p - str;
+}