diff options
Diffstat (limited to 'include/qapi')
| -rw-r--r-- | include/qapi/visitor-impl.h | 4 | ||||
| -rw-r--r-- | include/qapi/visitor.h | 40 |
2 files changed, 28 insertions, 16 deletions
diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h index 252206dc0d..98dc533d39 100644 --- a/include/qapi/visitor-impl.h +++ b/include/qapi/visitor-impl.h @@ -43,6 +43,10 @@ typedef enum VisitorType { struct Visitor { + /* + * Only input visitors may fail! + */ + /* Must be set to visit structs */ void (*start_struct)(Visitor *v, const char *name, void **obj, size_t size, Error **errp); diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h index 2d40d2fe0f..5573906966 100644 --- a/include/qapi/visitor.h +++ b/include/qapi/visitor.h @@ -82,7 +82,7 @@ * Each function also takes the customary @errp argument (see * qapi/error.h for details), for reporting any errors (such as if a * member @name is not present, or is present but not the specified - * type). + * type). Only input visitors can fail. * * If an error is detected during visit_type_FOO() with an input * visitor, then *@obj will be set to NULL for pointer types, and left @@ -164,19 +164,14 @@ * * <example> * Foo *f = ...obtain populated object... - * Error *err = NULL; * Visitor *v; * Type *result; * * v = FOO_visitor_new(..., &result); - * visit_type_Foo(v, NULL, &f, &err); - * if (err) { - * ...handle error... - * } else { - * visit_complete(v, &result); - * ...use result... - * } + * visit_type_Foo(v, NULL, &f, &error_abort); + * visit_complete(v, &result); * visit_free(v); + * ...use result... * </example> * * It is also possible to use the visitors to do a virtual walk, where @@ -289,6 +284,7 @@ void visit_free(Visitor *v); * case @size is ignored. * * On failure, set *@obj to NULL and store an error through @errp. + * Can happen only when @v is an input visitor. * * After visit_start_struct() succeeds, the caller may visit its * members one after the other, passing the member's name and address @@ -305,7 +301,8 @@ void visit_start_struct(Visitor *v, const char *name, void **obj, /* * Prepare for completing an object visit. * - * On failure, store an error through @errp. + * On failure, store an error through @errp. Can happen only when @v + * is an input visitor. * * Should be called prior to visit_end_struct() if all other * intermediate visit steps were successful, to allow the visitor one @@ -342,6 +339,7 @@ void visit_end_struct(Visitor *v, void **obj); * ignored. * * On failure, set *@list to NULL and store an error through @errp. + * Can happen only when @v is an input visitor. * * After visit_start_list() succeeds, the caller may visit its members * one after the other. A real visit (where @list is non-NULL) uses @@ -375,7 +373,8 @@ GenericList *visit_next_list(Visitor *v, GenericList *tail, size_t size); /* * Prepare for completing a list visit. * - * On failure, store an error through @errp. + * On failure, store an error through @errp. Can happen only when @v + * is an input visitor. * * Should be called prior to visit_end_list() if all other * intermediate visit steps were successful, to allow the visitor one @@ -411,6 +410,7 @@ void visit_end_list(Visitor *v, void **list); * (*@obj)->type. Other visitors leave @obj unchanged. * * On failure, set *@obj to NULL and store an error through @errp. + * Can happen only when @v is an input visitor. * * If successful, this must be paired with visit_end_alternate() with * the same @obj to clean up, even if visiting the contents of the @@ -465,11 +465,13 @@ bool visit_optional(Visitor *v, const char *name, bool *present); * visitors produce text output. The mapping between enumeration * values and strings is done by the visitor core, using @lookup. * - * On failure, store an error through @errp. + * On failure, store an error through @errp. Can happen only when @v + * is an input visitor. * * May call visit_type_str() under the hood, and the enum visit may * fail even if the corresponding string visit succeeded; this implies - * that visit_type_str() must have no unwelcome side effects. + * that an input visitor's visit_type_str() must have no unwelcome + * side effects. */ void visit_type_enum(Visitor *v, const char *name, int *obj, const QEnumLookup *lookup, Error **errp); @@ -495,7 +497,8 @@ bool visit_is_dealloc(Visitor *v); * @obj must be non-NULL. Input visitors set *@obj to the value; * other visitors will leave *@obj unchanged. * - * On failure, store an error through @errp. + * On failure, store an error through @errp. Can happen only when @v + * is an input visitor. */ void visit_type_int(Visitor *v, const char *name, int64_t *obj, Error **errp); @@ -573,7 +576,8 @@ void visit_type_size(Visitor *v, const char *name, uint64_t *obj, * @obj must be non-NULL. Input visitors set *@obj to the value; * other visitors will leave *@obj unchanged. * - * On failure, store an error through @errp. + * On failure, store an error through @errp. Can happen only when @v + * is an input visitor. */ void visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp); @@ -592,6 +596,7 @@ void visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp); * into @obj for use by an output visitor. * * On failure, set *@obj to NULL and store an error through @errp. + * Can happen only when @v is an input visitor. * * FIXME: Callers that try to output NULL *obj should not be allowed. */ @@ -607,7 +612,8 @@ void visit_type_str(Visitor *v, const char *name, char **obj, Error **errp); * other visitors will leave *@obj unchanged. Visitors should * document if infinity or NaN are not permitted. * - * On failure, store an error through @errp. + * On failure, store an error through @errp. Can happen only when @v + * is an input visitor. */ void visit_type_number(Visitor *v, const char *name, double *obj, Error **errp); @@ -623,6 +629,7 @@ void visit_type_number(Visitor *v, const char *name, double *obj, * for output visitors. * * On failure, set *@obj to NULL and store an error through @errp. + * Can happen only when @v is an input visitor. * * Note that some kinds of input can't express arbitrary QObject. * E.g. the visitor returned by qobject_input_visitor_new_keyval() @@ -640,6 +647,7 @@ void visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp); * other visitors ignore *@obj. * * On failure, set *@obj to NULL and store an error through @errp. + * Can happen only when @v is an input visitor. */ void visit_type_null(Visitor *v, const char *name, QNull **obj, Error **errp); |