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-rw-r--r--include/qapi/dealloc-visitor.h5
-rw-r--r--include/qapi/opts-visitor.h3
-rw-r--r--include/qapi/string-input-visitor.h4
-rw-r--r--include/qapi/string-output-visitor.h4
-rw-r--r--include/qapi/visitor-impl.h44
-rw-r--r--include/qapi/visitor.h447
-rw-r--r--qapi/qapi-visit-core.c18
7 files changed, 496 insertions, 29 deletions
diff --git a/include/qapi/dealloc-visitor.h b/include/qapi/dealloc-visitor.h
index cf4c36d2d3..45b06b248c 100644
--- a/include/qapi/dealloc-visitor.h
+++ b/include/qapi/dealloc-visitor.h
@@ -18,6 +18,11 @@
typedef struct QapiDeallocVisitor QapiDeallocVisitor;
+/*
+ * The dealloc visitor is primarly used only by generated
+ * qapi_free_FOO() functions, and is the only visitor designed to work
+ * correctly in the face of a partially-constructed QAPI tree.
+ */
QapiDeallocVisitor *qapi_dealloc_visitor_new(void);
void qapi_dealloc_visitor_cleanup(QapiDeallocVisitor *d);
diff --git a/include/qapi/opts-visitor.h b/include/qapi/opts-visitor.h
index fd48c14ec8..633aa7170f 100644
--- a/include/qapi/opts-visitor.h
+++ b/include/qapi/opts-visitor.h
@@ -29,6 +29,9 @@ typedef struct OptsVisitor OptsVisitor;
* - string representations of negative numbers yield negative values,
* - values below INT64_MIN or LLONG_MIN are rejected,
* - values above INT64_MAX or LLONG_MAX are rejected.
+ *
+ * The Opts input visitor does not implement support for visiting QAPI
+ * alternates, numbers (other than integers), or arbitrary QTypes.
*/
OptsVisitor *opts_visitor_new(const QemuOpts *opts);
void opts_visitor_cleanup(OptsVisitor *nv);
diff --git a/include/qapi/string-input-visitor.h b/include/qapi/string-input-visitor.h
index 089243c09e..fdf33ae2b4 100644
--- a/include/qapi/string-input-visitor.h
+++ b/include/qapi/string-input-visitor.h
@@ -17,6 +17,10 @@
typedef struct StringInputVisitor StringInputVisitor;
+/*
+ * The string input visitor does not implement support for visiting
+ * QAPI structs, alternates, or arbitrary QTypes.
+ */
StringInputVisitor *string_input_visitor_new(const char *str);
void string_input_visitor_cleanup(StringInputVisitor *v);
diff --git a/include/qapi/string-output-visitor.h b/include/qapi/string-output-visitor.h
index d99717f650..3bb09aff2f 100644
--- a/include/qapi/string-output-visitor.h
+++ b/include/qapi/string-output-visitor.h
@@ -17,6 +17,10 @@
typedef struct StringOutputVisitor StringOutputVisitor;
+/*
+ * The string output visitor does not implement support for visiting
+ * QAPI structs, alternates, or arbitrary QTypes.
+ */
StringOutputVisitor *string_output_visitor_new(bool human);
void string_output_visitor_cleanup(StringOutputVisitor *v);
diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h
index 51c338a43d..796d1800d4 100644
--- a/include/qapi/visitor-impl.h
+++ b/include/qapi/visitor-impl.h
@@ -15,6 +15,18 @@
#include "qapi/visitor.h"
/*
+ * This file describes the callback interface for implementing a QAPI
+ * visitor. For the client interface, see visitor.h. When
+ * implementing the callbacks, it is easiest to declare a struct with
+ * 'Visitor visitor;' as the first member. A callback's contract
+ * matches the corresponding public functions' contract unless stated
+ * otherwise. In the comments below, some callbacks are marked "must
+ * be set for $TYPE visits to work"; if a visitor implementation omits
+ * that callback, it should also document that it is only useful for a
+ * subset of QAPI.
+ */
+
+/*
* There are three classes of visitors; setting the class determines
* how QAPI enums are visited, as well as what additional restrictions
* can be asserted.
@@ -27,43 +39,59 @@ typedef enum VisitorType {
struct Visitor
{
- /* Must be set */
+ /* Must be set to visit structs */
void (*start_struct)(Visitor *v, const char *name, void **obj,
size_t size, Error **errp);
+
+ /* Must be set to visit structs */
void (*end_struct)(Visitor *v, Error **errp);
+ /* Must be set */
void (*start_list)(Visitor *v, const char *name, Error **errp);
+
/* Must be set */
GenericList *(*next_list)(Visitor *v, GenericList **list, size_t size);
+
/* Must be set */
void (*end_list)(Visitor *v);
- /* Optional, needed for input and dealloc visitors. */
+ /* Must be set by input and dealloc visitors to visit alternates;
+ * optional for output visitors. */
void (*start_alternate)(Visitor *v, const char *name,
GenericAlternate **obj, size_t size,
bool promote_int, Error **errp);
- /* Optional, needed for dealloc visitor. */
+ /* Optional, needed for dealloc visitor */
void (*end_alternate)(Visitor *v);
- /* Must be set. */
+ /* Must be set */
void (*type_int64)(Visitor *v, const char *name, int64_t *obj,
Error **errp);
- /* Must be set. */
+
+ /* Must be set */
void (*type_uint64)(Visitor *v, const char *name, uint64_t *obj,
Error **errp);
- /* Optional; fallback is type_uint64(). */
+
+ /* Optional; fallback is type_uint64() */
void (*type_size)(Visitor *v, const char *name, uint64_t *obj,
Error **errp);
- /* Must be set. */
+
+ /* Must be set */
void (*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);
+
+ /* Must be set to visit numbers */
void (*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,
Error **errp);
- /* May be NULL; most useful for input visitors. */
+ /* Must be set for input visitors, optional otherwise. The core
+ * takes care of the return type in the public interface. */
void (*optional)(Visitor *v, const char *name, bool *present);
/* Must be set */
diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h
index 690589f37d..221163742c 100644
--- a/include/qapi/visitor.h
+++ b/include/qapi/visitor.h
@@ -16,8 +16,196 @@
#include "qapi/qmp/qobject.h"
+/*
+ * The QAPI schema defines both a set of C data types, and a QMP wire
+ * format. QAPI objects can contain references to other QAPI objects,
+ * resulting in a directed acyclic graph. QAPI also generates visitor
+ * functions to walk these graphs. This file represents the interface
+ * for doing work at each node of a QAPI graph; it can also be used
+ * for a virtual walk, where there is no actual QAPI C struct.
+ *
+ * There are three kinds of visitor classes: input visitors (QMP,
+ * string, and QemuOpts) parse an external representation and build
+ * the corresponding QAPI graph, output visitors (QMP and string) take
+ * a completed QAPI graph and generate an external representation, and
+ * the dealloc visitor can take a QAPI graph (possibly partially
+ * constructed) and recursively free its resources. While the dealloc
+ * and QMP input/output visitors are general, the string and QemuOpts
+ * visitors have some implementation limitations; see the
+ * documentation for each visitor for more details on what it
+ * supports. Also, see visitor-impl.h for the callback contracts
+ * implemented by each visitor, and docs/qapi-code-gen.txt for more
+ * about the QAPI code generator.
+ *
+ * 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);
+ *
+ * where T is FOO for scalar types, and FOO * otherwise. The scalar
+ * visitors are declared here; the remaining visitors are generated in
+ * qapi-visit.h.
+ *
+ * The @name parameter of visit_type_FOO() describes the relation
+ * between this QAPI value and its parent container. When visiting
+ * the root of a tree, @name is ignored; when visiting a member of an
+ * object, @name is the key associated with the value; and when
+ * visiting a member of a list, @name is NULL.
+ *
+ * FIXME: Clients must pass NULL for @name when visiting a member of a
+ * list, but this leads to poor error messages; it might be nicer to
+ * require a non-NULL name such as "key.0" for '{ "key": [ "value" ]
+ * }' if an error is encountered on "value" (or to have the visitor
+ * core auto-generate the nicer name).
+ *
+ * The visit_type_FOO() functions expect a non-null @obj argument;
+ * they allocate *@obj during input visits, leave it unchanged on
+ * output visits, and recursively free any resources during a dealloc
+ * visit. 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).
+ *
+ * FIXME: At present, visit_type_FOO() is an awkward interface: input
+ * visitors may allocate an incomplete *@obj even when reporting an
+ * error, but using an output visitor with an incomplete object has
+ * undefined behavior. To avoid a memory leak, callers must use
+ * qapi_free_FOO() even on error (this uses the dealloc visitor, and
+ * safely handles an incomplete object).
+ *
+ * For the QAPI object types (structs, unions, and alternates), there
+ * is an additional generated function in qapi-visit.h compatible
+ * with:
+ *
+ * void visit_type_FOO_members(Visitor *v, FOO *obj, Error **errp);
+ *
+ * for visiting the members of a type without also allocating the QAPI
+ * struct.
+ *
+ * Additionally, in qapi-types.h, all QAPI pointer types (structs,
+ * unions, alternates, and lists) have a generated function compatible
+ * with:
+ *
+ * void qapi_free_FOO(FOO *obj);
+ *
+ * which behaves like free() in that @obj may be NULL. Because of
+ * these functions, the dealloc visitor is seldom used directly
+ * outside of generated code. QAPI types can also inherit from a base
+ * class; when this happens, a function is generated for easily going
+ * from the derived type to the base type:
+ *
+ * BASE *qapi_CHILD_base(CHILD *obj);
+ *
+ * For a real QAPI struct, typical input usage involves:
+ *
+ * <example>
+ * Foo *f;
+ * Error *err = NULL;
+ * Visitor *v;
+ *
+ * v = ...obtain input visitor...
+ * visit_type_Foo(v, NULL, &f, &err);
+ * if (err) {
+ * qapi_free_Foo(f);
+ * ...handle error...
+ * } else {
+ * ...use f...
+ * }
+ * ...clean up v...
+ * qapi_free_Foo(f);
+ * </example>
+ *
+ * For a list, it is:
+ * <example>
+ * FooList *l;
+ * Error *err = NULL;
+ * Visitor *v;
+ *
+ * v = ...obtain input visitor...
+ * visit_type_FooList(v, NULL, &l, &err);
+ * if (err) {
+ * qapi_free_FooList(l);
+ * ...handle error...
+ * } else {
+ * for ( ; l; l = l->next) {
+ * ...use l->value...
+ * }
+ * }
+ * ...clean up v...
+ * qapi_free_FooList(l);
+ * </example>
+ *
+ * Similarly, typical output usage is:
+ *
+ * <example>
+ * Foo *f = ...obtain populated object...
+ * Error *err = NULL;
+ * Visitor *v;
+ *
+ * v = ...obtain output visitor...
+ * visit_type_Foo(v, NULL, &f, &err);
+ * if (err) {
+ * ...handle error...
+ * }
+ * ...clean up v...
+ * </example>
+ *
+ * When visiting a real QAPI struct, this file provides several
+ * helpers that rely on in-tree information to control the walk:
+ * visit_optional() for the 'has_member' field associated with
+ * optional 'member' in the C struct; and visit_next_list() for
+ * advancing through a FooList linked list. Only the generated
+ * visit_type functions need to use these helpers.
+ *
+ * It is also possible to use the visitors to do a virtual walk, where
+ * no actual QAPI struct is present. In this situation, decisions
+ * about what needs to be walked are made by the calling code, and
+ * structured visits are split between pairs of start and end methods
+ * (where the end method must be called if the start function
+ * succeeded, even if an intermediate visit encounters an error).
+ * Thus, a virtual walk corresponding to '{ "list": [1, 2] }' looks
+ * like:
+ *
+ * <example>
+ * Visitor *v;
+ * Error *err = NULL;
+ * int value;
+ *
+ * v = ...obtain visitor...
+ * visit_start_struct(v, NULL, NULL, 0, &err);
+ * if (err) {
+ * goto out;
+ * }
+ * visit_start_list(v, "list", &err);
+ * if (err) {
+ * goto outobj;
+ * }
+ * value = 1;
+ * visit_type_int(v, NULL, &value, &err);
+ * if (err) {
+ * goto outlist;
+ * }
+ * value = 2;
+ * visit_type_int(v, NULL, &value, &err);
+ * if (err) {
+ * goto outlist;
+ * }
+ * outlist:
+ * visit_end_list(v);
+ * outobj:
+ * error_propagate(errp, err);
+ * err = NULL;
+ * visit_end_struct(v, &err);
+ * out:
+ * error_propagate(errp, err);
+ * ...clean up v...
+ * </example>
+ */
+
+/*** Useful types ***/
+
/* This struct is layout-compatible with all other *List structs
- * created by the qapi generator. It is used as a typical
+ * created by the QAPI generator. It is used as a typical
* singly-linked list. */
typedef struct GenericList {
struct GenericList *next;
@@ -25,35 +213,126 @@ typedef struct GenericList {
} GenericList;
/* This struct is layout-compatible with all Alternate types
- * created by the qapi generator. */
+ * created by the QAPI generator. */
typedef struct GenericAlternate {
QType type;
char padding[];
} GenericAlternate;
+/*** Visiting structures ***/
+
+/*
+ * Start visiting an object @obj (struct or union).
+ *
+ * @name expresses the relationship of this object to its parent
+ * container; see the general description of @name above.
+ *
+ * @obj must be non-NULL for a real walk, in which case @size
+ * determines how much memory an input visitor will allocate into
+ * *@obj. @obj may also be NULL for a virtual walk, in which case
+ * @size is ignored.
+ *
+ * @errp obeys typical error usage, and reports failures such as a
+ * member @name is not present, or present but not an object. On
+ * error, input visitors set *@obj to NULL.
+ *
+ * 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
+ * to clean up, even if intermediate visits fail. See the examples
+ * above.
+ *
+ * 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,
size_t size, Error **errp);
+
+/*
+ * Complete an object visit started earlier.
+ *
+ * @errp obeys typical error usage, and reports failures such as
+ * unparsed keys remaining in the input stream.
+ *
+ * Must be called after any successful use of visit_start_struct(),
+ * even if intermediate processing was skipped due to errors, to allow
+ * the backend to release any resources. Destroying the visitor early
+ * behaves as if this was implicitly called.
+ */
void visit_end_struct(Visitor *v, Error **errp);
+
+/*** Visiting lists ***/
+
+/*
+ * Start visiting a list.
+ *
+ * @name expresses the relationship of this list to its parent
+ * container; see the general description of @name above.
+ *
+ * @errp obeys typical error usage, and reports failures such as a
+ * member @name is not present, or present but not a list.
+ *
+ * After visit_start_list() succeeds, the caller may visit its members
+ * one after the other. A real visit uses visit_next_list() for
+ * traversing the linked list, while a virtual visit uses other means.
+ * For each list element, call the appropriate visit_type_FOO() with
+ * name set to NULL and obj set to the address of the value member of
+ * the list element. Finally, visit_end_list() needs to be called to
+ * clean up, even if intermediate visits fail. See the examples
+ * above.
+ */
void visit_start_list(Visitor *v, const char *name, Error **errp);
+
+/*
+ * Iterate over a GenericList during a non-virtual list visit.
+ *
+ * @size represents the size of a linked list node (at least
+ * sizeof(GenericList)).
+ *
+ * @list must not be NULL; on the first call, @list contains the
+ * address of the list head, and on subsequent calls *@list must be
+ * the previously returned value. Should be called in a loop until a
+ * NULL return or error occurs; for each non-NULL return, the caller
+ * then calls the appropriate visit_type_*() for the element type
+ * of the list, with that function's name parameter set to NULL and
+ * obj set to the address of (*@list)->value.
+ *
+ * FIXME: This interface is awkward; it requires all callbacks to
+ * track whether it is the first or a subsequent call. A better
+ * interface would pass the head of the list through
+ * visit_start_list().
+ */
GenericList *visit_next_list(Visitor *v, GenericList **list, size_t size);
+
+/*
+ * Complete a list visit started earlier.
+ *
+ * Must be called after any successful use of visit_start_list(), even
+ * if intermediate processing was skipped due to errors, to allow the
+ * backend to release any resources. Destroying the visitor early
+ * behaves as if this was implicitly called.
+ */
void visit_end_list(Visitor *v);
+
+/*** Visiting alternates ***/
+
/*
- * Start the visit of an alternate @obj with the given @size.
+ * Start the visit of an alternate @obj.
*
- * @name specifies the relationship to the containing struct (ignored
- * for a top level visit, the name of the key if this alternate is
- * part of an object, or NULL if this alternate is part of a list).
+ * @name expresses the relationship of this alternate to its parent
+ * container; see the general description of @name above.
*
- * @obj must not be NULL. Input visitors will allocate @obj and
- * determine the qtype of the next thing to be visited, stored in
- * (*@obj)->type. Other visitors will leave @obj unchanged.
+ * @obj must not be NULL. Input visitors use @size to determine how
+ * much memory to allocate into *@obj, then determine the qtype of the
+ * next thing to be visited, stored in (*@obj)->type. Other visitors
+ * will leave @obj unchanged.
*
* If @promote_int, treat integers as QTYPE_FLOAT.
*
- * If successful, this must be paired with visit_end_alternate(), even
- * if visiting the contents of the alternate fails.
+ * If successful, this must be paired with visit_end_alternate() to
+ * clean up, even if visiting the contents of the alternate fails.
*/
void visit_start_alternate(Visitor *v, const char *name,
GenericAlternate **obj, size_t size,
@@ -62,27 +341,48 @@ void visit_start_alternate(Visitor *v, const char *name,
/*
* Finish visiting an alternate type.
*
- * Must be called after a successful visit_start_alternate(), even if
- * an error occurred in the meantime.
+ * Must be called after any successful use of visit_start_alternate(),
+ * even if intermediate processing was skipped due to errors, to allow
+ * the backend to release any resources. Destroying the visitor early
+ * behaves as if this was implicitly called.
*
* TODO: Should all the visit_end_* interfaces take obj parameter, so
* that dealloc visitor need not track what was passed in visit_start?
*/
void visit_end_alternate(Visitor *v);
-/**
- * Check if an optional member @name of an object needs visiting.
- * For input visitors, set *@present according to whether the
- * corresponding visit_type_*() needs calling; for other visitors,
- * leave *@present unchanged. Return *@present for convenience.
+
+/*** Other helpers ***/
+
+/*
+ * Does optional struct member @name need visiting?
+ *
+ * @name must not be NULL. This function is only useful between
+ * visit_start_struct() and visit_end_struct(), since only objects
+ * have optional keys.
+ *
+ * @present points to the address of the optional member's has_ flag.
+ *
+ * Input visitors set *@present according to input; other visitors
+ * leave it unchanged. In either case, return *@present for
+ * convenience.
*/
bool visit_optional(Visitor *v, const char *name, bool *present);
/*
* Visit an enum value.
*
- * @strings expresses the mapping between C enum values and QAPI enum
- * names; it should be the ENUM_lookup array from visit-types.h.
+ * @name expresses the relationship of this enum to its parent
+ * container; see the general description of @name above.
+ *
+ * @obj must be non-NULL. Input visitors parse input and set *@obj to
+ * the enumeration value, leaving @obj unchanged on error; other
+ * visitors use *@obj but leave it unchanged.
+ *
+ * Currently, all input visitors parse text input, and all output
+ * visitors produce text output. The mapping between enumeration
+ * values and strings is done by the visitor core, using @strings; it
+ * should be the ENUM_lookup array from visit-types.h.
*
* May call visit_type_str() under the hood, and the enum visit may
* fail even if the corresponding string visit succeeded; this implies
@@ -91,28 +391,135 @@ bool visit_optional(Visitor *v, const char *name, bool *present);
void visit_type_enum(Visitor *v, const char *name, int *obj,
const char *const strings[], Error **errp);
+/*** Visiting built-in types ***/
+
+/*
+ * Visit an integer value.
+ *
+ * @name expresses the relationship of this integer to its parent
+ * container; see the general description of @name above.
+ *
+ * @obj must be non-NULL. Input visitors set *@obj to the value;
+ * other visitors will leave *@obj unchanged.
+ */
void 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,
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,
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,
Error **errp);
+
+/*
+ * Visit a uint64_t value.
+ * 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,
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);
+
+/*
+ * 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,
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,
Error **errp);
+
+/*
+ * Visit an int64_t value.
+ * Identical to visit_type_int().
+ */
void visit_type_int64(Visitor *v, const char *name, int64_t *obj,
Error **errp);
+
+/*
+ * Visit a uint64_t value.
+ * Like visit_type_uint64(), except that some visitors may choose to
+ * recognize additional syntax, such as suffixes for easily scaling
+ * values.
+ */
void visit_type_size(Visitor *v, const char *name, uint64_t *obj,
Error **errp);
+
+/*
+ * Visit a boolean value.
+ *
+ * @name expresses the relationship of this boolean to its parent
+ * container; see the general description of @name above.
+ *
+ * @obj must be non-NULL. Input visitors set *@obj to the value;
+ * other visitors will leave *@obj unchanged.
+ */
void visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp);
+
+/*
+ * Visit a string value.
+ *
+ * @name expresses the relationship of this string to its parent
+ * container; see the general description of @name above.
+ *
+ * @obj must be non-NULL. Input visitors set *@obj to the value
+ * (never NULL). Other visitors leave *@obj unchanged, and commonly
+ * treat NULL like "".
+ *
+ * It is safe to cast away const when preparing a (const char *) value
+ * into @obj for use by an output visitor.
+ *
+ * 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);
+
+/*
+ * Visit a number (i.e. double) value.
+ *
+ * @name expresses the relationship of this number to its parent
+ * container; see the general description of @name above.
+ *
+ * @obj must be non-NULL. Input visitors set *@obj to the value;
+ * other visitors will leave *@obj unchanged. Visitors should
+ * document if infinity or NaN are not permitted.
+ */
void visit_type_number(Visitor *v, const char *name, double *obj,
Error **errp);
+
+/*
+ * Visit an arbitrary value.
+ *
+ * @name expresses the relationship of this value to its parent
+ * container; see the general description of @name above.
+ *
+ * @obj must be non-NULL. Input visitors set *@obj to the value;
+ * other visitors will leave *@obj unchanged. *@obj must be non-NULL
+ * for output visitors.
+ */
void visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp);
#endif
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 528092e55f..0f59a1d8e5 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -25,6 +25,10 @@ void visit_start_struct(Visitor *v, const char *name, void **obj,
{
Error *err = NULL;
+ if (obj) {
+ assert(size);
+ assert(v->type != VISITOR_OUTPUT || *obj);
+ }
v->start_struct(v, name, obj, size, &err);
if (obj && v->type == VISITOR_INPUT) {
assert(!err != !*obj);
@@ -60,6 +64,7 @@ void visit_start_alternate(Visitor *v, const char *name,
Error *err = NULL;
assert(obj && size >= sizeof(GenericAlternate));
+ assert(v->type != VISITOR_OUTPUT || *obj);
if (v->start_alternate) {
v->start_alternate(v, name, obj, size, promote_int, &err);
}
@@ -86,6 +91,7 @@ bool visit_optional(Visitor *v, const char *name, bool *present)
void visit_type_int(Visitor *v, const char *name, int64_t *obj, Error **errp)
{
+ assert(obj);
v->type_int64(v, name, obj, errp);
}
@@ -133,6 +139,7 @@ void visit_type_uint32(Visitor *v, const char *name, uint32_t *obj,
void visit_type_uint64(Visitor *v, const char *name, uint64_t *obj,
Error **errp)
{
+ assert(obj);
v->type_uint64(v, name, obj, errp);
}
@@ -180,12 +187,14 @@ void visit_type_int32(Visitor *v, const char *name, int32_t *obj,
void visit_type_int64(Visitor *v, const char *name, int64_t *obj,
Error **errp)
{
+ assert(obj);
v->type_int64(v, name, obj, errp);
}
void visit_type_size(Visitor *v, const char *name, uint64_t *obj,
Error **errp)
{
+ assert(obj);
if (v->type_size) {
v->type_size(v, name, obj, errp);
} else {
@@ -195,6 +204,7 @@ void visit_type_size(Visitor *v, const char *name, uint64_t *obj,
void visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp)
{
+ assert(obj);
v->type_bool(v, name, obj, errp);
}
@@ -203,6 +213,10 @@ void visit_type_str(Visitor *v, const char *name, char **obj, Error **errp)
Error *err = NULL;
assert(obj);
+ /* TODO: Fix callers to not pass NULL when they mean "", so that we
+ * can enable:
+ assert(v->type != VISITOR_OUTPUT || *obj);
+ */
v->type_str(v, name, obj, &err);
if (v->type == VISITOR_INPUT) {
assert(!err != !*obj);
@@ -213,6 +227,7 @@ void visit_type_str(Visitor *v, const char *name, char **obj, Error **errp)
void visit_type_number(Visitor *v, const char *name, double *obj,
Error **errp)
{
+ assert(obj);
v->type_number(v, name, obj, errp);
}
@@ -221,6 +236,7 @@ void visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp)
Error *err = NULL;
assert(obj);
+ assert(v->type != VISITOR_OUTPUT || *obj);
v->type_any(v, name, obj, &err);
if (v->type == VISITOR_INPUT) {
assert(!err != !*obj);
@@ -278,7 +294,7 @@ static void input_type_enum(Visitor *v, const char *name, int *obj,
void visit_type_enum(Visitor *v, const char *name, int *obj,
const char *const strings[], Error **errp)
{
- assert(strings);
+ assert(obj && strings);
if (v->type == VISITOR_INPUT) {
input_type_enum(v, name, obj, strings, errp);
} else if (v->type == VISITOR_OUTPUT) {