[v2,2/4] qapi: Do not consume a value when visit_type_enum() fails

Commit Message

Akihiko Odaki July 14, 2024, 7:48 a.m. UTC

Consuming a value when visit_type_enum() fails makes it impossible to
reinterpret the value with a different type.

Signed-off-by: Akihiko Odaki <[e-mail]>
---
 include/qapi/visitor.h | 5 -----
 qapi/opts-visitor.c    | 5 -----
 qapi/qapi-visit-core.c | 4 +++-
 3 files changed, 3 insertions(+), 11 deletions(-)

Patch

diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h
index b3ae3188edfb..8e841b26428b 100644
--- a/include/qapi/visitor.h
+++ b/include/qapi/visitor.h
@@ -513,11 +513,6 @@  void visit_set_policy(Visitor *v, CompatPolicy *policy);
  * is an input visitor.
  *
  * Return true on success, false on failure.
- *
- * May call visit_type_str() under the hood, and the enum visit may
- * fail even if the corresponding string visit succeeded; this implies
- * that an input visitor's visit_type_str() must have no unwelcome
- * side effects.
  */
 bool visit_type_enum(Visitor *v, const char *name, int *obj,
                      const QEnumLookup *lookup, Error **errp);
diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c
index e9fad756e189..d83434b95a56 100644
--- a/qapi/opts-visitor.c
+++ b/qapi/opts-visitor.c
@@ -359,11 +359,6 @@  opts_type_str(Visitor *v, const char *name, char **obj, bool consume,
         return false;
     }
     *obj = g_strdup(opt->str ? opt->str : "");
-    /* Note that we consume a string even if this is called as part of
-     * an enum visit that later fails because the string is not a
-     * valid enum value; this is harmless because tracking what gets
-     * consumed only matters to visit_end_struct() as the final error
-     * check if there were no other failures during the visit.  */
     if (consume) {
         processed(ov, name);
     }
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 89b52fc99202..1137d472290b 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -411,7 +411,7 @@  static bool input_type_enum(Visitor *v, const char *name, int *obj,
     int64_t value;
     g_autofree char *enum_str = NULL;
 
-    if (!visit_type_str(v, name, &enum_str, errp)) {
+    if (!visit_type_str_preserving(v, name, &enum_str, errp)) {
         return false;
     }
 
@@ -430,6 +430,8 @@  static bool input_type_enum(Visitor *v, const char *name, int *obj,
         return false;
     }
 
+    enum_str = NULL;
+    visit_type_str(v, name, &enum_str, &error_abort);
     *obj = value;
     return true;
 }