diff options
Diffstat (limited to 'include/qapi')
| -rw-r--r-- | include/qapi/clone-visitor.h | 8 | ||||
| -rw-r--r-- | include/qapi/error.h | 261 | ||||
| -rw-r--r-- | include/qapi/visitor-impl.h | 26 | ||||
| -rw-r--r-- | include/qapi/visitor.h | 102 |
4 files changed, 307 insertions, 90 deletions
diff --git a/include/qapi/clone-visitor.h b/include/qapi/clone-visitor.h index 5b665ee38c..adf9a788e2 100644 --- a/include/qapi/clone-visitor.h +++ b/include/qapi/clone-visitor.h @@ -20,10 +20,10 @@ */ typedef struct QapiCloneVisitor QapiCloneVisitor; -void *qapi_clone(const void *src, void (*visit_type)(Visitor *, const char *, +void *qapi_clone(const void *src, bool (*visit_type)(Visitor *, const char *, void **, Error **)); void qapi_clone_members(void *dst, const void *src, size_t sz, - void (*visit_type_members)(Visitor *, void *, + bool (*visit_type_members)(Visitor *, void *, Error **)); /* @@ -34,7 +34,7 @@ void qapi_clone_members(void *dst, const void *src, size_t sz, */ #define QAPI_CLONE(type, src) \ ((type *)qapi_clone(src, \ - (void (*)(Visitor *, const char *, void**, \ + (bool (*)(Visitor *, const char *, void **, \ Error **))visit_type_ ## type)) /* @@ -45,7 +45,7 @@ void qapi_clone_members(void *dst, const void *src, size_t sz, */ #define QAPI_CLONE_MEMBERS(type, dst, src) \ qapi_clone_members(dst, src, sizeof(type), \ - (void (*)(Visitor *, void *, \ + (bool (*)(Visitor *, void *, \ Error **))visit_type_ ## type ## _members) #endif diff --git a/include/qapi/error.h b/include/qapi/error.h index ad5b6e896d..7932594dce 100644 --- a/include/qapi/error.h +++ b/include/qapi/error.h @@ -15,18 +15,55 @@ /* * Error reporting system loosely patterned after Glib's GError. * + * = Rules = + * + * - Functions that use Error to report errors have an Error **errp + * parameter. It should be the last parameter, except for functions + * taking variable arguments. + * + * - You may pass NULL to not receive the error, &error_abort to abort + * on error, &error_fatal to exit(1) on error, or a pointer to a + * variable containing NULL to receive the error. + * + * - Separation of concerns: the function is responsible for detecting + * errors and failing cleanly; handling the error is its caller's + * job. Since the value of @errp is about handling the error, the + * function should not examine it. + * + * - The function may pass @errp to functions it calls to pass on + * their errors to its caller. If it dereferences @errp to check + * for errors, it must use ERRP_GUARD(). + * + * - On success, the function should not touch *errp. On failure, it + * should set a new error, e.g. with error_setg(errp, ...), or + * propagate an existing one, e.g. with error_propagate(errp, ...). + * + * - Whenever practical, also return a value that indicates success / + * failure. This can make the error checking more concise, and can + * avoid useless error object creation and destruction. Note that + * we still have many functions returning void. We recommend + * • bool-valued functions return true on success / false on failure, + * • pointer-valued functions return non-null / null pointer, and + * • integer-valued functions return non-negative / negative. + * + * = Creating errors = + * * Create an error: - * error_setg(&err, "situation normal, all fouled up"); + * error_setg(errp, "situation normal, all fouled up"); + * where @errp points to the location to receive the error. * * Create an error and add additional explanation: - * error_setg(&err, "invalid quark"); - * error_append_hint(&err, "Valid quarks are up, down, strange, " + * error_setg(errp, "invalid quark"); + * error_append_hint(errp, "Valid quarks are up, down, strange, " * "charm, top, bottom.\n"); + * This may require use of ERRP_GUARD(); more on that below. * * Do *not* contract this to - * error_setg(&err, "invalid quark\n" + * error_setg(errp, "invalid quark\n" // WRONG! * "Valid quarks are up, down, strange, charm, top, bottom."); * + * = Reporting and destroying errors = + * * Report an error to the current monitor if we have one, else stderr: * error_report_err(err); * This frees the error object. @@ -40,6 +77,30 @@ * error_free(err); * Note that this loses hints added with error_append_hint(). * + * Call a function ignoring errors: + * foo(arg, NULL); + * This is more concise than + * Error *err = NULL; + * foo(arg, &err); + * error_free(err); // don't do this + * + * Call a function aborting on errors: + * foo(arg, &error_abort); + * This is more concise and fails more nicely than + * Error *err = NULL; + * foo(arg, &err); + * assert(!err); // don't do this + * + * Call a function treating errors as fatal: + * foo(arg, &error_fatal); + * This is more concise than + * Error *err = NULL; + * foo(arg, &err); + * if (err) { // don't do this + * error_report_err(err); + * exit(1); + * } + * * Handle an error without reporting it (just for completeness): * error_free(err); * @@ -47,57 +108,73 @@ * reporting it (primarily useful in testsuites): * error_free_or_abort(&err); * - * Pass an existing error to the caller: - * error_propagate(errp, err); - * where Error **errp is a parameter, by convention the last one. + * = Passing errors around = * - * Pass an existing error to the caller with the message modified: - * error_propagate_prepend(errp, err); - * - * Avoid - * error_propagate(errp, err); - * error_prepend(errp, "Could not frobnicate '%s': ", name); - * because this fails to prepend when @errp is &error_fatal. + * Errors get passed to the caller through the conventional @errp + * parameter. * * Create a new error and pass it to the caller: * error_setg(errp, "situation normal, all fouled up"); * - * Call a function and receive an error from it: - * Error *err = NULL; - * foo(arg, &err); - * if (err) { + * Call a function, receive an error from it, and pass it to the caller + * - when the function returns a value that indicates failure, say + * false: + * if (!foo(arg, errp)) { * handle the error... * } + * - when it does not, say because it is a void function: + * ERRP_GUARD(); + * foo(arg, errp); + * if (*errp) { + * handle the error... + * } + * More on ERRP_GUARD() below. * - * Call a function ignoring errors: - * foo(arg, NULL); - * - * Call a function aborting on errors: - * foo(arg, &error_abort); - * - * Call a function treating errors as fatal: - * foo(arg, &error_fatal); - * - * Receive an error and pass it on to the caller: + * Code predating ERRP_GUARD() still exists, and looks like this: * Error *err = NULL; * foo(arg, &err); * if (err) { * handle the error... - * error_propagate(errp, err); + * error_propagate(errp, err); // deprecated * } - * where Error **errp is a parameter, by convention the last one. - * - * Do *not* "optimize" this to + * Avoid in new code. Do *not* "optimize" it to * foo(arg, errp); * if (*errp) { // WRONG! * handle the error... * } - * because errp may be NULL! + * because errp may be NULL without the ERRP_GUARD() guard. * * But when all you do with the error is pass it on, please use * foo(arg, errp); * for readability. * + * Receive an error, and handle it locally + * - when the function returns a value that indicates failure, say + * false: + * Error *err = NULL; + * if (!foo(arg, &err)) { + * handle the error... + * } + * - when it does not, say because it is a void function: + * Error *err = NULL; + * foo(arg, &err); + * if (err) { + * handle the error... + * } + * + * Pass an existing error to the caller: + * error_propagate(errp, err); + * This is rarely needed. When @err is a local variable, use of + * ERRP_GUARD() commonly results in more readable code. + * + * Pass an existing error to the caller with the message modified: + * error_propagate_prepend(errp, err, + * "Could not frobnicate '%s': ", name); + * This is more concise than + * error_propagate(errp, err); // don't do this + * error_prepend(errp, "Could not frobnicate '%s': ", name); + * and works even when @errp is &error_fatal. + * * Receive and accumulate multiple errors (first one wins): * Error *err = NULL, *local_err = NULL; * foo(arg, &err); @@ -108,12 +185,88 @@ * } * * Do *not* "optimize" this to + * Error *err = NULL; * foo(arg, &err); * bar(arg, &err); // WRONG! * if (err) { * handle the error... * } * because this may pass a non-null err to bar(). + * + * Likewise, do *not* + * Error *err = NULL; + * if (cond1) { + * error_setg(&err, ...); + * } + * if (cond2) { + * error_setg(&err, ...); // WRONG! + * } + * because this may pass a non-null err to error_setg(). + * + * = Why, when and how to use ERRP_GUARD() = + * + * Without ERRP_GUARD(), use of the @errp parameter is restricted: + * - It must not be dereferenced, because it may be null. + * - It should not be passed to error_prepend() or + * error_append_hint(), because that doesn't work with &error_fatal. + * ERRP_GUARD() lifts these restrictions. + * + * To use ERRP_GUARD(), add it right at the beginning of the function. + * @errp can then be used without worrying about the argument being + * NULL or &error_fatal. + * + * Using it when it's not needed is safe, but please avoid cluttering + * the source with useless code. + * + * = Converting to ERRP_GUARD() = + * + * To convert a function to use ERRP_GUARD(): + * + * 0. If the Error ** parameter is not named @errp, rename it to + * @errp. + * + * 1. Add an ERRP_GUARD() invocation, by convention right at the + * beginning of the function. This makes @errp safe to use. + * + * 2. Replace &err by errp, and err by *errp. Delete local variable + * @err. + * + * 3. Delete error_propagate(errp, *errp), replace + * error_propagate_prepend(errp, *errp, ...) by error_prepend(errp, ...) + * + * 4. Ensure @errp is valid at return: when you destroy *errp, set + * errp = NULL. + * + * Example: + * + * bool fn(..., Error **errp) + * { + * Error *err = NULL; + * + * foo(arg, &err); + * if (err) { + * handle the error... + * error_propagate(errp, err); + * return false; + * } + * ... + * } + * + * becomes + * + * bool fn(..., Error **errp) + * { + * ERRP_GUARD(); + * + * foo(arg, errp); + * if (*errp) { + * handle the error... + * return false; + * } + * ... + * } + * + * For mass-conversion, use scripts/coccinelle/errp-guard.cocci. */ #ifndef ERROR_H @@ -214,6 +367,7 @@ void error_setg_win32_internal(Error **errp, * the error object. * Else, move the error object from @local_err to *@dst_errp. * On return, @local_err is invalid. + * Please use ERRP_GUARD() instead when possible. * Please don't error_propagate(&error_fatal, ...), use * error_report_err() and exit(), because that's more obvious. */ @@ -225,6 +379,7 @@ void error_propagate(Error **dst_errp, Error *local_err); * Behaves like * error_prepend(&local_err, fmt, ...); * error_propagate(dst_errp, local_err); + * Please use ERRP_GUARD() and error_prepend() instead when possible. */ void error_propagate_prepend(Error **dst_errp, Error *local_err, const char *fmt, ...); @@ -323,6 +478,46 @@ void error_set_internal(Error **errp, GCC_FMT_ATTR(6, 7); /* + * Make @errp parameter easier to use regardless of argument value + * + * This macro is for use right at the beginning of a function that + * takes an Error **errp parameter to pass errors to its caller. The + * parameter must be named @errp. + * + * It must be used when the function dereferences @errp or passes + * @errp to error_prepend(), error_vprepend(), or error_append_hint(). + * It is safe to use even when it's not needed, but please avoid + * cluttering the source with useless code. + * + * If @errp is NULL or &error_fatal, rewrite it to point to a local + * Error variable, which will be automatically propagated to the + * original @errp on function exit. + * + * Note: &error_abort is not rewritten, because that would move the + * abort from the place where the error is created to the place where + * it's propagated. + */ +#define ERRP_GUARD() \ + g_auto(ErrorPropagator) _auto_errp_prop = {.errp = errp}; \ + do { \ + if (!errp || errp == &error_fatal) { \ + errp = &_auto_errp_prop.local_err; \ + } \ + } while (0) + +typedef struct ErrorPropagator { + Error *local_err; + Error **errp; +} ErrorPropagator; + +static inline void error_propagator_cleanup(ErrorPropagator *prop) +{ + error_propagate(prop->errp, prop->local_err); +} + +G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(ErrorPropagator, error_propagator_cleanup); + +/* * Special error destination to abort on error. * See error_setg() and error_propagate() for details. */ diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h index 98dc533d39..7362c043be 100644 --- a/include/qapi/visitor-impl.h +++ b/include/qapi/visitor-impl.h @@ -48,31 +48,31 @@ struct Visitor */ /* Must be set to visit structs */ - void (*start_struct)(Visitor *v, const char *name, void **obj, + bool (*start_struct)(Visitor *v, const char *name, void **obj, size_t size, Error **errp); /* Optional; intended for input visitors */ - void (*check_struct)(Visitor *v, Error **errp); + bool (*check_struct)(Visitor *v, Error **errp); /* Must be set to visit structs */ void (*end_struct)(Visitor *v, void **obj); /* Must be set; implementations may require @list to be non-null, * but must document it. */ - void (*start_list)(Visitor *v, const char *name, GenericList **list, + bool (*start_list)(Visitor *v, const char *name, GenericList **list, size_t size, Error **errp); /* Must be set */ GenericList *(*next_list)(Visitor *v, GenericList *tail, size_t size); /* Optional; intended for input visitors */ - void (*check_list)(Visitor *v, Error **errp); + bool (*check_list)(Visitor *v, Error **errp); /* Must be set */ void (*end_list)(Visitor *v, void **list); /* Must be set by input and clone visitors to visit alternates */ - void (*start_alternate)(Visitor *v, const char *name, + bool (*start_alternate)(Visitor *v, const char *name, GenericAlternate **obj, size_t size, Error **errp); @@ -80,33 +80,33 @@ struct Visitor void (*end_alternate)(Visitor *v, void **obj); /* Must be set */ - void (*type_int64)(Visitor *v, const char *name, int64_t *obj, + bool (*type_int64)(Visitor *v, const char *name, int64_t *obj, Error **errp); /* Must be set */ - void (*type_uint64)(Visitor *v, const char *name, uint64_t *obj, + bool (*type_uint64)(Visitor *v, const char *name, uint64_t *obj, Error **errp); /* Optional; fallback is type_uint64() */ - void (*type_size)(Visitor *v, const char *name, uint64_t *obj, + bool (*type_size)(Visitor *v, const char *name, uint64_t *obj, Error **errp); /* Must be set */ - void (*type_bool)(Visitor *v, const char *name, bool *obj, Error **errp); + bool (*type_bool)(Visitor *v, const char *name, bool *obj, Error **errp); /* Must be set */ - void (*type_str)(Visitor *v, const char *name, char **obj, Error **errp); + bool (*type_str)(Visitor *v, const char *name, char **obj, Error **errp); /* Must be set to visit numbers */ - void (*type_number)(Visitor *v, const char *name, double *obj, + bool (*type_number)(Visitor *v, const char *name, double *obj, Error **errp); /* Must be set to visit arbitrary QTypes */ - void (*type_any)(Visitor *v, const char *name, QObject **obj, + bool (*type_any)(Visitor *v, const char *name, QObject **obj, Error **errp); /* Must be set to visit explicit null values. */ - void (*type_null)(Visitor *v, const char *name, QNull **obj, + bool (*type_null)(Visitor *v, const char *name, QNull **obj, Error **errp); /* Must be set for input visitors to visit structs, optional otherwise. 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 |