json-parser: propagate error from parser

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/json-parser.c b/json-parser.c
index 6c06ef9..ac4063a 100644
--- a/json-parser.c
+++ b/json-parser.c
@@ -22,9 +22,11 @@
 #include "qbool.h"
 #include "json-parser.h"
 #include "json-lexer.h"
+#include "qerror.h"
 
 typedef struct JSONParserContext
 {
+    Error *err;
 } JSONParserContext;
 
 #define BUG_ON(cond) assert(!(cond))
@@ -95,11 +97,15 @@
                                            QObject *token, const char *msg, ...)
 {
     va_list ap;
+    char message[1024];
     va_start(ap, msg);
-    fprintf(stderr, "parse error: ");
-    vfprintf(stderr, msg, ap);
-    fprintf(stderr, "\n");
+    vsnprintf(message, sizeof(message), msg, ap);
     va_end(ap);
+    if (ctxt->err) {
+        error_free(ctxt->err);
+        ctxt->err = NULL;
+    }
+    error_set(&ctxt->err, QERR_JSON_PARSE_ERROR, message);
 }
 
 /**
@@ -565,6 +571,11 @@
 
 QObject *json_parser_parse(QList *tokens, va_list *ap)
 {
+    return json_parser_parse_err(tokens, ap, NULL);
+}
+
+QObject *json_parser_parse_err(QList *tokens, va_list *ap, Error **errp)
+{
     JSONParserContext ctxt = {};
     QList *working = qlist_copy(tokens);
     QObject *result;
@@ -573,5 +584,7 @@
 
     QDECREF(working);
 
+    error_propagate(errp, ctxt.err);
+
     return result;
 }