diff options
Diffstat (limited to 'include/qapi/visitor.h')
| -rw-r--r-- | include/qapi/visitor.h | 102 |
1 files changed, 62 insertions, 40 deletions
diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h index 5573906966..ebc19ede7f 100644 --- a/include/qapi/visitor.h +++ b/include/qapi/visitor.h @@ -60,7 +60,7 @@ * All QAPI types have a corresponding function with a signature * roughly compatible with this: * - * void visit_type_FOO(Visitor *v, const char *name, T obj, Error **errp); + * bool visit_type_FOO(Visitor *v, const char *name, T obj, Error **errp); * * where T is FOO for scalar types, and FOO * otherwise. The scalar * visitors are declared here; the remaining visitors are generated in @@ -95,14 +95,16 @@ * incomplete object, such an object is possible only by manual * construction. * + * visit_type_FOO() returns true on success, false on error. + * * For the QAPI object types (structs, unions, and alternates), there * is an additional generated function in qapi-visit-MODULE.h * compatible with: * - * void visit_type_FOO_members(Visitor *v, FOO *obj, Error **errp); + * bool visit_type_FOO_members(Visitor *v, FOO *obj, Error **errp); * * for visiting the members of a type without also allocating the QAPI - * struct. + * struct. It also returns true on success, false on error. * * Additionally, QAPI pointer types (structs, unions, alternates, and * lists) have a generated function in qapi-types-MODULE.h compatible @@ -131,8 +133,7 @@ * Visitor *v; * * v = FOO_visitor_new(...); - * visit_type_Foo(v, NULL, &f, &err); - * if (err) { + * if (!visit_type_Foo(v, NULL, &f, &err)) { * ...handle error... * } else { * ...use f... @@ -148,8 +149,7 @@ * Visitor *v; * * v = FOO_visitor_new(...); - * visit_type_FooList(v, NULL, &l, &err); - * if (err) { + * if (!visit_type_FooList(v, NULL, &l, &err)) { * ...handle error... * } else { * for ( ; l; l = l->next) { @@ -186,34 +186,32 @@ * <example> * Visitor *v; * Error *err = NULL; + * bool ok = false; * int value; * * v = FOO_visitor_new(...); - * visit_start_struct(v, NULL, NULL, 0, &err); - * if (err) { + * if (!visit_start_struct(v, NULL, NULL, 0, &err)) { * goto out; * } - * visit_start_list(v, "list", NULL, 0, &err); - * if (err) { + * if (!visit_start_list(v, "list", NULL, 0, &err)) { * goto outobj; * } * value = 1; - * visit_type_int(v, NULL, &value, &err); - * if (err) { + * if (!visit_type_int(v, NULL, &value, &err)) { * goto outlist; * } * value = 2; - * visit_type_int(v, NULL, &value, &err); - * if (err) { + * if (!visit_type_int(v, NULL, &value, &err)) { * goto outlist; * } + * ok = true; * outlist: - * if (!err) { - * visit_check_list(v, &err); + * if (ok) { + * ok = visit_check_list(v, &err); * } * visit_end_list(v, NULL); - * if (!err) { - * visit_check_struct(v, &err); + * if (ok) { + * ok = visit_check_struct(v, &err); * } * outobj: * visit_end_struct(v, NULL); @@ -286,6 +284,8 @@ void visit_free(Visitor *v); * On failure, set *@obj to NULL and store an error through @errp. * Can happen only when @v is an input visitor. * + * Return true on success, false on failure. + * * After visit_start_struct() succeeds, the caller may visit its * members one after the other, passing the member's name and address * within the struct. Finally, visit_end_struct() needs to be called @@ -295,7 +295,7 @@ void visit_free(Visitor *v); * FIXME Should this be named visit_start_object, since it is also * used for QAPI unions, and maps to JSON objects? */ -void visit_start_struct(Visitor *v, const char *name, void **obj, +bool visit_start_struct(Visitor *v, const char *name, void **obj, size_t size, Error **errp); /* @@ -304,12 +304,14 @@ void visit_start_struct(Visitor *v, const char *name, void **obj, * On failure, store an error through @errp. Can happen only when @v * is an input visitor. * + * Return true on success, false on failure. + * * Should be called prior to visit_end_struct() if all other * intermediate visit steps were successful, to allow the visitor one * last chance to report errors. May be skipped on a cleanup path, * where there is no need to check for further errors. */ -void visit_check_struct(Visitor *v, Error **errp); +bool visit_check_struct(Visitor *v, Error **errp); /* * Complete an object visit started earlier. @@ -341,6 +343,8 @@ void visit_end_struct(Visitor *v, void **obj); * On failure, set *@list to NULL and store an error through @errp. * Can happen only when @v is an input visitor. * + * Return true on success, false on failure. + * * After visit_start_list() succeeds, the caller may visit its members * one after the other. A real visit (where @list is non-NULL) uses * visit_next_list() for traversing the linked list, while a virtual @@ -351,7 +355,7 @@ void visit_end_struct(Visitor *v, void **obj); * same @list to clean up, even if intermediate visits fail. See the * examples above. */ -void visit_start_list(Visitor *v, const char *name, GenericList **list, +bool visit_start_list(Visitor *v, const char *name, GenericList **list, size_t size, Error **errp); /* @@ -376,12 +380,14 @@ GenericList *visit_next_list(Visitor *v, GenericList *tail, size_t size); * On failure, store an error through @errp. Can happen only when @v * is an input visitor. * + * Return true on success, false on failure. + * * Should be called prior to visit_end_list() if all other * intermediate visit steps were successful, to allow the visitor one * last chance to report errors. May be skipped on a cleanup path, * where there is no need to check for further errors. */ -void visit_check_list(Visitor *v, Error **errp); +bool visit_check_list(Visitor *v, Error **errp); /* * Complete a list visit started earlier. @@ -412,11 +418,13 @@ void visit_end_list(Visitor *v, void **list); * On failure, set *@obj to NULL and store an error through @errp. * Can happen only when @v is an input visitor. * + * Return true on success, false on failure. + * * If successful, this must be paired with visit_end_alternate() with * the same @obj to clean up, even if visiting the contents of the * alternate fails. */ -void visit_start_alternate(Visitor *v, const char *name, +bool visit_start_alternate(Visitor *v, const char *name, GenericAlternate **obj, size_t size, Error **errp); @@ -468,12 +476,14 @@ bool visit_optional(Visitor *v, const char *name, bool *present); * On failure, store an error through @errp. Can happen only when @v * 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. */ -void visit_type_enum(Visitor *v, const char *name, int *obj, +bool visit_type_enum(Visitor *v, const char *name, int *obj, const QEnumLookup *lookup, Error **errp); /* @@ -499,28 +509,30 @@ bool visit_is_dealloc(Visitor *v); * * On failure, store an error through @errp. Can happen only when @v * is an input visitor. + * + * Return true on success, false on failure. */ -void visit_type_int(Visitor *v, const char *name, int64_t *obj, Error **errp); +bool visit_type_int(Visitor *v, const char *name, int64_t *obj, Error **errp); /* * Visit a uint8_t value. * Like visit_type_int(), except clamps the value to uint8_t range. */ -void visit_type_uint8(Visitor *v, const char *name, uint8_t *obj, +bool visit_type_uint8(Visitor *v, const char *name, uint8_t *obj, Error **errp); /* * Visit a uint16_t value. * Like visit_type_int(), except clamps the value to uint16_t range. */ -void visit_type_uint16(Visitor *v, const char *name, uint16_t *obj, +bool visit_type_uint16(Visitor *v, const char *name, uint16_t *obj, Error **errp); /* * Visit a uint32_t value. * Like visit_type_int(), except clamps the value to uint32_t range. */ -void visit_type_uint32(Visitor *v, const char *name, uint32_t *obj, +bool visit_type_uint32(Visitor *v, const char *name, uint32_t *obj, Error **errp); /* @@ -528,34 +540,34 @@ void visit_type_uint32(Visitor *v, const char *name, uint32_t *obj, * Like visit_type_int(), except clamps the value to uint64_t range, * that is, ensures it is unsigned. */ -void visit_type_uint64(Visitor *v, const char *name, uint64_t *obj, +bool visit_type_uint64(Visitor *v, const char *name, uint64_t *obj, Error **errp); /* * Visit an int8_t value. * Like visit_type_int(), except clamps the value to int8_t range. */ -void visit_type_int8(Visitor *v, const char *name, int8_t *obj, Error **errp); +bool visit_type_int8(Visitor *v, const char *name, int8_t *obj, Error **errp); /* * Visit an int16_t value. * Like visit_type_int(), except clamps the value to int16_t range. */ -void visit_type_int16(Visitor *v, const char *name, int16_t *obj, +bool visit_type_int16(Visitor *v, const char *name, int16_t *obj, Error **errp); /* * Visit an int32_t value. * Like visit_type_int(), except clamps the value to int32_t range. */ -void visit_type_int32(Visitor *v, const char *name, int32_t *obj, +bool visit_type_int32(Visitor *v, const char *name, int32_t *obj, Error **errp); /* * Visit an int64_t value. * Identical to visit_type_int(). */ -void visit_type_int64(Visitor *v, const char *name, int64_t *obj, +bool visit_type_int64(Visitor *v, const char *name, int64_t *obj, Error **errp); /* @@ -564,7 +576,7 @@ void visit_type_int64(Visitor *v, const char *name, int64_t *obj, * recognize additional syntax, such as suffixes for easily scaling * values. */ -void visit_type_size(Visitor *v, const char *name, uint64_t *obj, +bool visit_type_size(Visitor *v, const char *name, uint64_t *obj, Error **errp); /* @@ -578,8 +590,10 @@ void visit_type_size(Visitor *v, const char *name, uint64_t *obj, * * On failure, store an error through @errp. Can happen only when @v * is an input visitor. + * + * Return true on success, false on failure. */ -void visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp); +bool visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp); /* * Visit a string value. @@ -598,9 +612,11 @@ void visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp); * On failure, set *@obj to NULL and store an error through @errp. * Can happen only when @v is an input visitor. * + * Return true on success, false on failure. + * * FIXME: Callers that try to output NULL *obj should not be allowed. */ -void visit_type_str(Visitor *v, const char *name, char **obj, Error **errp); +bool visit_type_str(Visitor *v, const char *name, char **obj, Error **errp); /* * Visit a number (i.e. double) value. @@ -614,8 +630,10 @@ void visit_type_str(Visitor *v, const char *name, char **obj, Error **errp); * * On failure, store an error through @errp. Can happen only when @v * is an input visitor. + * + * Return true on success, false on failure. */ -void visit_type_number(Visitor *v, const char *name, double *obj, +bool visit_type_number(Visitor *v, const char *name, double *obj, Error **errp); /* @@ -631,11 +649,13 @@ void visit_type_number(Visitor *v, const char *name, double *obj, * On failure, set *@obj to NULL and store an error through @errp. * Can happen only when @v is an input visitor. * + * Return true on success, false on failure. + * * Note that some kinds of input can't express arbitrary QObject. * E.g. the visitor returned by qobject_input_visitor_new_keyval() * can't create numbers or booleans, only strings. */ -void visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp); +bool visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp); /* * Visit a JSON null value. @@ -648,8 +668,10 @@ void visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp); * * On failure, set *@obj to NULL and store an error through @errp. * Can happen only when @v is an input visitor. + * + * Return true on success, false on failure. */ -void visit_type_null(Visitor *v, const char *name, QNull **obj, +bool visit_type_null(Visitor *v, const char *name, QNull **obj, Error **errp); #endif |