json: Eliminate lexer state IN_ERROR

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180831075841.13363-6-armbru@redhat.com>

qobject/json-lexer.c

@@ -100,8 +100,7 @@
  */
 
 enum json_lexer_state {
-    IN_ERROR = 0,               /* must really be 0, see json_lexer[] */
-    IN_RECOVERY,
+    IN_RECOVERY = 1,
     IN_DQ_STRING_ESCAPE,
     IN_DQ_STRING,
     IN_SQ_STRING_ESCAPE,
@@ -121,6 +120,8 @@ enum json_lexer_state {
     IN_START_INTERP,            /* must be IN_START + 1 */
 };
 
+QEMU_BUILD_BUG_ON(JSON_ERROR != 0);
+QEMU_BUILD_BUG_ON(IN_RECOVERY != JSON_ERROR + 1);
 QEMU_BUILD_BUG_ON((int)JSON_MIN <= (int)IN_START_INTERP);
 QEMU_BUILD_BUG_ON(JSON_MAX >= 0x80);
 QEMU_BUILD_BUG_ON(IN_START_INTERP != IN_START + 1);
@@ -176,7 +177,7 @@ static const uint8_t json_lexer[][256] =  {
     /* Zero */
     [IN_ZERO] = {
         TERMINAL(JSON_INTEGER),
-        ['0' ... '9'] = IN_ERROR,
+        ['0' ... '9'] = JSON_ERROR,
         ['.'] = IN_MANTISSA,
     },
 
@@ -328,7 +329,7 @@ static void json_lexer_feed_char(JSONLexer *lexer, char ch, bool flush)
         case IN_START:
             new_state = lexer->start_state;
             break;
-        case IN_ERROR:
+        case JSON_ERROR:
             json_message_process_token(lexer, lexer->token, JSON_ERROR,
                                        lexer->x, lexer->y);
             new_state = IN_RECOVERY;

qobject/json-parser-int.h

@@ -16,10 +16,11 @@
 
 #include "qapi/qmp/json-parser.h"
 
-
 typedef enum json_token_type {
-    JSON_MIN = 100,
-    JSON_LCURLY = JSON_MIN,
+    JSON_ERROR = 0,             /* must be zero, see json_lexer[] */
+    /* Gap for lexer states */
+    JSON_LCURLY = 100,
+    JSON_MIN = JSON_LCURLY,
     JSON_RCURLY,
     JSON_LSQUARE,
     JSON_RSQUARE,
@@ -31,7 +32,6 @@ typedef enum json_token_type {
     JSON_STRING,
     JSON_INTERP,
     JSON_SKIP,
-    JSON_ERROR,
     JSON_END_OF_INPUT,
     JSON_MAX = JSON_END_OF_INPUT
 } JSONTokenType;