json-streamer: do not heap-allocate JSONToken

This is not needed with a push parser.  Since it processes tokens
immediately, the JSONToken can be created directly on the stack
and does not need to copy the lexer's string data.

Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20260626101727.1727389-6-pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

3 files changed, 13 insertions, 22 deletions

diff --git a/qobject/json-parser-int.h b/qobject/json-parser-int.h
index 1f435cb8eb..5a6b5c9af9 100644
--- a/qobject/json-parser-int.h
+++ b/qobject/json-parser-int.h
@@ -35,7 +35,12 @@ typedef enum json_token_type {
     JSON_MAX = JSON_END_OF_INPUT
 } JSONTokenType;
 
-typedef struct JSONToken JSONToken;
+typedef struct JSONToken {
+    JSONTokenType type;
+    int x;
+    int y;
+    char *str;
+} JSONToken;
 
 /* json-lexer.c */
 void json_lexer_init(JSONLexer *lexer, bool enable_interpolation);
@@ -48,7 +53,6 @@ void json_message_process_token(JSONLexer *lexer, GString *input,
                                 JSONTokenType type, int x, int y);
 
 /* json-parser.c */
-JSONToken *json_token(JSONTokenType type, int x, int y, GString *tokstr);
 void json_parser_init(JSONParserContext *ctxt, va_list *ap);
 void json_parser_reset(JSONParserContext *ctxt);
 QObject *json_parser_feed(JSONParserContext *ctxt, const JSONToken *token, Error **errp);
diff --git a/qobject/json-parser.c b/qobject/json-parser.c
index 79a2989e7a..0dcc94fefd 100644
--- a/qobject/json-parser.c
+++ b/qobject/json-parser.c
@@ -24,13 +24,6 @@
 #include "qobject/qstring.h"
 #include "json-parser-int.h"
 
-struct JSONToken {
-    JSONTokenType type;
-    int x;
-    int y;
-    char str[];
-};
-
 /*
  * The JSON parser is a push parser, returning a completed top-level
  * object, an error, or NULL (if the object is incomplete and no error
@@ -624,17 +617,6 @@ static QObject *parse_token(JSONParserContext *ctxt, const JSONToken *token)
     return NULL;
 }
 
-JSONToken *json_token(JSONTokenType type, int x, int y, GString *tokstr)
-{
-    JSONToken *token = g_malloc(sizeof(JSONToken) + tokstr->len + 1);
-
-    token->type = type;
-    memcpy(token->str, tokstr->str, tokstr->len);
-    token->str[tokstr->len] = 0;
-    token->x = x;
-    token->y = y;
-    return token;
-}
 
 void json_parser_reset(JSONParserContext *ctxt)
 {
diff --git a/qobject/json-streamer.c b/qobject/json-streamer.c
index 48c5506771..b634bbe99c 100644
--- a/qobject/json-streamer.c
+++ b/qobject/json-streamer.c
@@ -78,8 +78,13 @@ void json_message_process_token(JSONLexer *lexer, GString *input,
         } else if (parser->bracket_count + parser->brace_count > MAX_NESTING) {
             error_setg(&err, "JSON nesting depth limit exceeded");
         } else {
-            g_autofree JSONToken *token = json_token(type, x, y, input);
-            QObject *json = json_parser_feed(&parser->parser, token, &err);
+            JSONToken token = (JSONToken) {
+                .type = type,
+                .x = x,
+                .y = y,
+                .str = input->str
+            };
+            QObject *json = json_parser_feed(&parser->parser, &token, &err);
             if (json) {
                 parser->emit(parser->opaque, json, NULL);
             }