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unicorn/qemu/qapi/qmp-output-visitor.c

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import
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/*
* Core Definitions for QAPI/QMP Command Registry
*
* Copyright IBM, Corp. 2011
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
* See the COPYING.LIB file in the top-level directory.
*
*/
qapi: Clean up includes Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Backports commit cbf21151906c935d4276268b59429c58546462ae from qemu
2018-02-19 06:29:26 +00:00
#include "qemu/osdep.h"
include/qemu/osdep.h: Don't include qapi/error.h Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the Error typedef. Since then, we've moved to include qemu/osdep.h everywhere. Its file comment explains: "To avoid getting into possible circular include dependencies, this file should not include any other QEMU headers, with the exceptions of config-host.h, compiler.h, os-posix.h and os-win32.h, all of which are doing a similar job to this file and are under similar constraints." qapi/error.h doesn't do a similar job, and it doesn't adhere to similar constraints: it includes qapi-types.h. That's in excess of 100KiB of crap most .c files don't actually need. Add the typedef to qemu/typedefs.h, and include that instead of qapi/error.h. Include qapi/error.h in .c files that need it and don't get it now. Include qapi-types.h in qom/object.h for uint16List. Update scripts/clean-includes accordingly. Update it further to match reality: replace config.h by config-target.h, add sysemu/os-posix.h, sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h comment quoted above similarly. This reduces the number of objects depending on qapi/error.h from "all of them" to less than a third. Unfortunately, the number depending on qapi-types.h shrinks only a little. More work is needed for that one. Backports commit da34e65cb4025728566d6504a99916f6e7e1dd6a from qemu
2018-02-22 04:05:15 +00:00
#include "qapi/error.h"
import
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#include "qapi/qmp-output-visitor.h"
#include "qapi/visitor-impl.h"
#include "qemu/queue.h"
#include "qemu-common.h"
#include "qapi/qmp/types.h"
#include "qapi/qmp/qerror.h"
typedef struct QStackEntry
{
QObject *value;
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
void *qapi; /* sanity check that caller uses same pointer */
import
2015-08-21 07:04:50 +00:00
QTAILQ_ENTRY(QStackEntry) node;
} QStackEntry;
typedef QTAILQ_HEAD(QStack, QStackEntry) QStack;
struct QmpOutputVisitor
{
Visitor visitor;
qmp: Don't abuse stack to track qmp-output root The previous commit documented an inconsistency in how we are using the stack of qmp-output-visitor. Normally, pushing a single top-level object puts the object on the stack twice: once as the root, and once as the current container being appended to; but popping that struct only pops once. However, qmp_ouput_add() was trying to either set up the added object as the new root (works if you parse two top-level scalars in a row: the second replaces the first as the root) or as a member of the current container (works as long as you have an open container on the stack; but if you have popped the first top-level container, it then resolves to the root and still tries to add into that existing container). Fix the stupidity by not tracking two separate things in the stack. Drop the now-useless qmp_output_first() and qmp_output_last() while at it. Saved for a later patch: we still are rather sloppy in that qmp_output_get_object() can be called in the middle of a parse, rather than requiring that a visit is complete. Backports commit 455ba08afde784466420449d01c6458f88349d55 from qemu
2018-02-20 13:09:55 +00:00
QStack stack; /* Stack of containers that haven't yet been finished */
QObject *root; /* Root of the output visit */
import
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};
#define qmp_output_add(qov, name, value) \
qmp_output_add_obj(qov, name, QOBJECT(value))
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
#define qmp_output_push(qov, value, qapi) \
qmp_output_push_obj(qov, QOBJECT(value), qapi)
import
2015-08-21 07:04:50 +00:00
static QmpOutputVisitor *to_qov(Visitor *v)
{
return container_of(v, QmpOutputVisitor, visitor);
}
qmp: Fix reference-counting of qnull on empty output visit Commit 6c2f9a15 ensured that we would not return NULL when the caller used an output visitor but had nothing to visit. But in doing so, it added a FIXME about a reference count leak that could abort qemu in the (unlikely) case of SIZE_MAX such visits (more plausible on 32-bit). (Although that commit suggested we might fix it in time for 2.5, we ran out of time; fortunately, it is unlikely enough to bite that it was not worth worrying about during the 2.5 release.) This fixes things by documenting the internal contracts, and explaining why the internal function can return NULL and only the public facing interface needs to worry about qnull(), thus avoiding over-referencing the qnull_ global object. It does not, however, fix the stupidity of the stack mixing up two separate pieces of information; add a FIXME to explain that issue, which will be fixed shortly in a future patch. Backports commit a86156401559cb4401cf9ecc704faeab6fc8bb19 from qemu
2018-02-20 13:07:24 +00:00
/* Push @value onto the stack of current QObjects being built */
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
static void qmp_output_push_obj(QmpOutputVisitor *qov, QObject *value,
void *qapi)
import
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{
QStackEntry *e = g_malloc0(sizeof(*e));
qmp: Don't abuse stack to track qmp-output root The previous commit documented an inconsistency in how we are using the stack of qmp-output-visitor. Normally, pushing a single top-level object puts the object on the stack twice: once as the root, and once as the current container being appended to; but popping that struct only pops once. However, qmp_ouput_add() was trying to either set up the added object as the new root (works if you parse two top-level scalars in a row: the second replaces the first as the root) or as a member of the current container (works as long as you have an open container on the stack; but if you have popped the first top-level container, it then resolves to the root and still tries to add into that existing container). Fix the stupidity by not tracking two separate things in the stack. Drop the now-useless qmp_output_first() and qmp_output_last() while at it. Saved for a later patch: we still are rather sloppy in that qmp_output_get_object() can be called in the middle of a parse, rather than requiring that a visit is complete. Backports commit 455ba08afde784466420449d01c6458f88349d55 from qemu
2018-02-20 13:09:55 +00:00
assert(qov->root);
qmp: Fix reference-counting of qnull on empty output visit Commit 6c2f9a15 ensured that we would not return NULL when the caller used an output visitor but had nothing to visit. But in doing so, it added a FIXME about a reference count leak that could abort qemu in the (unlikely) case of SIZE_MAX such visits (more plausible on 32-bit). (Although that commit suggested we might fix it in time for 2.5, we ran out of time; fortunately, it is unlikely enough to bite that it was not worth worrying about during the 2.5 release.) This fixes things by documenting the internal contracts, and explaining why the internal function can return NULL and only the public facing interface needs to worry about qnull(), thus avoiding over-referencing the qnull_ global object. It does not, however, fix the stupidity of the stack mixing up two separate pieces of information; add a FIXME to explain that issue, which will be fixed shortly in a future patch. Backports commit a86156401559cb4401cf9ecc704faeab6fc8bb19 from qemu
2018-02-20 13:07:24 +00:00
assert(value);
import
2015-08-21 07:04:50 +00:00
e->value = value;
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
e->qapi = qapi;
import
2015-08-21 07:04:50 +00:00
QTAILQ_INSERT_HEAD(&qov->stack, e, node);
}
qmp: Fix reference-counting of qnull on empty output visit Commit 6c2f9a15 ensured that we would not return NULL when the caller used an output visitor but had nothing to visit. But in doing so, it added a FIXME about a reference count leak that could abort qemu in the (unlikely) case of SIZE_MAX such visits (more plausible on 32-bit). (Although that commit suggested we might fix it in time for 2.5, we ran out of time; fortunately, it is unlikely enough to bite that it was not worth worrying about during the 2.5 release.) This fixes things by documenting the internal contracts, and explaining why the internal function can return NULL and only the public facing interface needs to worry about qnull(), thus avoiding over-referencing the qnull_ global object. It does not, however, fix the stupidity of the stack mixing up two separate pieces of information; add a FIXME to explain that issue, which will be fixed shortly in a future patch. Backports commit a86156401559cb4401cf9ecc704faeab6fc8bb19 from qemu
2018-02-20 13:07:24 +00:00
/* Pop a value off the stack of QObjects being built, and return it. */
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
static QObject *qmp_output_pop(QmpOutputVisitor *qov, void *qapi)
import
2015-08-21 07:04:50 +00:00
{
QStackEntry *e = QTAILQ_FIRST(&qov->stack);
QObject *value;
qmp: Fix reference-counting of qnull on empty output visit Commit 6c2f9a15 ensured that we would not return NULL when the caller used an output visitor but had nothing to visit. But in doing so, it added a FIXME about a reference count leak that could abort qemu in the (unlikely) case of SIZE_MAX such visits (more plausible on 32-bit). (Although that commit suggested we might fix it in time for 2.5, we ran out of time; fortunately, it is unlikely enough to bite that it was not worth worrying about during the 2.5 release.) This fixes things by documenting the internal contracts, and explaining why the internal function can return NULL and only the public facing interface needs to worry about qnull(), thus avoiding over-referencing the qnull_ global object. It does not, however, fix the stupidity of the stack mixing up two separate pieces of information; add a FIXME to explain that issue, which will be fixed shortly in a future patch. Backports commit a86156401559cb4401cf9ecc704faeab6fc8bb19 from qemu
2018-02-20 13:07:24 +00:00
assert(e);
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
assert(e->qapi == qapi);
import
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QTAILQ_REMOVE(&qov->stack, e, node);
value = e->value;
qmp: Fix reference-counting of qnull on empty output visit Commit 6c2f9a15 ensured that we would not return NULL when the caller used an output visitor but had nothing to visit. But in doing so, it added a FIXME about a reference count leak that could abort qemu in the (unlikely) case of SIZE_MAX such visits (more plausible on 32-bit). (Although that commit suggested we might fix it in time for 2.5, we ran out of time; fortunately, it is unlikely enough to bite that it was not worth worrying about during the 2.5 release.) This fixes things by documenting the internal contracts, and explaining why the internal function can return NULL and only the public facing interface needs to worry about qnull(), thus avoiding over-referencing the qnull_ global object. It does not, however, fix the stupidity of the stack mixing up two separate pieces of information; add a FIXME to explain that issue, which will be fixed shortly in a future patch. Backports commit a86156401559cb4401cf9ecc704faeab6fc8bb19 from qemu
2018-02-20 13:07:24 +00:00
assert(value);
revert to use of g_free to make future qemu integrations easier (#695) * revert to use of g_free to make future qemu integrations easier * bracing
2016-12-21 14:28:36 +00:00
g_free(e);
import
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return value;
}
qmp: Fix reference-counting of qnull on empty output visit Commit 6c2f9a15 ensured that we would not return NULL when the caller used an output visitor but had nothing to visit. But in doing so, it added a FIXME about a reference count leak that could abort qemu in the (unlikely) case of SIZE_MAX such visits (more plausible on 32-bit). (Although that commit suggested we might fix it in time for 2.5, we ran out of time; fortunately, it is unlikely enough to bite that it was not worth worrying about during the 2.5 release.) This fixes things by documenting the internal contracts, and explaining why the internal function can return NULL and only the public facing interface needs to worry about qnull(), thus avoiding over-referencing the qnull_ global object. It does not, however, fix the stupidity of the stack mixing up two separate pieces of information; add a FIXME to explain that issue, which will be fixed shortly in a future patch. Backports commit a86156401559cb4401cf9ecc704faeab6fc8bb19 from qemu
2018-02-20 13:07:24 +00:00
/* Add @value to the current QObject being built.
* If the stack is visiting a dictionary or list, @value is now owned
* by that container. Otherwise, @value is now the root. */
import
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static void qmp_output_add_obj(QmpOutputVisitor *qov, const char *name,
QObject *value)
{
qmp: Don't abuse stack to track qmp-output root The previous commit documented an inconsistency in how we are using the stack of qmp-output-visitor. Normally, pushing a single top-level object puts the object on the stack twice: once as the root, and once as the current container being appended to; but popping that struct only pops once. However, qmp_ouput_add() was trying to either set up the added object as the new root (works if you parse two top-level scalars in a row: the second replaces the first as the root) or as a member of the current container (works as long as you have an open container on the stack; but if you have popped the first top-level container, it then resolves to the root and still tries to add into that existing container). Fix the stupidity by not tracking two separate things in the stack. Drop the now-useless qmp_output_first() and qmp_output_last() while at it. Saved for a later patch: we still are rather sloppy in that qmp_output_get_object() can be called in the middle of a parse, rather than requiring that a visit is complete. Backports commit 455ba08afde784466420449d01c6458f88349d55 from qemu
2018-02-20 13:09:55 +00:00
QStackEntry *e = QTAILQ_FIRST(&qov->stack);
QObject *cur = e ? e->value : NULL;
import
2015-08-21 07:04:50 +00:00
qmp: Don't abuse stack to track qmp-output root The previous commit documented an inconsistency in how we are using the stack of qmp-output-visitor. Normally, pushing a single top-level object puts the object on the stack twice: once as the root, and once as the current container being appended to; but popping that struct only pops once. However, qmp_ouput_add() was trying to either set up the added object as the new root (works if you parse two top-level scalars in a row: the second replaces the first as the root) or as a member of the current container (works as long as you have an open container on the stack; but if you have popped the first top-level container, it then resolves to the root and still tries to add into that existing container). Fix the stupidity by not tracking two separate things in the stack. Drop the now-useless qmp_output_first() and qmp_output_last() while at it. Saved for a later patch: we still are rather sloppy in that qmp_output_get_object() can be called in the middle of a parse, rather than requiring that a visit is complete. Backports commit 455ba08afde784466420449d01c6458f88349d55 from qemu
2018-02-20 13:09:55 +00:00
if (!cur) {
qmp: Tighten output visitor rules Tighten assertions in the QMP output visitor, so that: - qmp_output_get_qobject() can only be called after pairing a visit_end_* for every visit_start_* (rather than allowing it on a partially built object) - qmp_output_get_qobject() cannot be called unless at least one visit_type_* or visit_start/visit_end pair has occurred since creation/reset (the accidental return of NULL fixed by commit ab8bf1d7 would have been much easier to diagnose) - ensure that we are encountering the expected object or list type, to provide protection against mismatched push(struct)/ pop(list) or push(list)/pop(struct), similar to the qmp-input protection added in commit bdd8e6b5. - ensure that except for the root, 'name' is non-null inside a dict, and NULL inside a list (this may need changing later if we add "name.0" support for better error messages for a list, but for now it makes sure all users are at least consistent) Backports commit 56a6f02b8ce1fe41a2a9077593e46eca7d98267d from qemu
2018-02-24 00:04:38 +00:00
/* Don't allow reuse of visitor on more than one root */
assert(!qov->root);
qmp: Don't abuse stack to track qmp-output root The previous commit documented an inconsistency in how we are using the stack of qmp-output-visitor. Normally, pushing a single top-level object puts the object on the stack twice: once as the root, and once as the current container being appended to; but popping that struct only pops once. However, qmp_ouput_add() was trying to either set up the added object as the new root (works if you parse two top-level scalars in a row: the second replaces the first as the root) or as a member of the current container (works as long as you have an open container on the stack; but if you have popped the first top-level container, it then resolves to the root and still tries to add into that existing container). Fix the stupidity by not tracking two separate things in the stack. Drop the now-useless qmp_output_first() and qmp_output_last() while at it. Saved for a later patch: we still are rather sloppy in that qmp_output_get_object() can be called in the middle of a parse, rather than requiring that a visit is complete. Backports commit 455ba08afde784466420449d01c6458f88349d55 from qemu
2018-02-20 13:09:55 +00:00
qov->root = value;
} else {
switch (qobject_type(cur)) {
case QTYPE_QDICT:
assert(name);
qdict_put_obj(qobject_to_qdict(cur), name, value);
break;
case QTYPE_QLIST:
qmp: Tighten output visitor rules Tighten assertions in the QMP output visitor, so that: - qmp_output_get_qobject() can only be called after pairing a visit_end_* for every visit_start_* (rather than allowing it on a partially built object) - qmp_output_get_qobject() cannot be called unless at least one visit_type_* or visit_start/visit_end pair has occurred since creation/reset (the accidental return of NULL fixed by commit ab8bf1d7 would have been much easier to diagnose) - ensure that we are encountering the expected object or list type, to provide protection against mismatched push(struct)/ pop(list) or push(list)/pop(struct), similar to the qmp-input protection added in commit bdd8e6b5. - ensure that except for the root, 'name' is non-null inside a dict, and NULL inside a list (this may need changing later if we add "name.0" support for better error messages for a list, but for now it makes sure all users are at least consistent) Backports commit 56a6f02b8ce1fe41a2a9077593e46eca7d98267d from qemu
2018-02-24 00:04:38 +00:00
assert(!name);
qmp: Don't abuse stack to track qmp-output root The previous commit documented an inconsistency in how we are using the stack of qmp-output-visitor. Normally, pushing a single top-level object puts the object on the stack twice: once as the root, and once as the current container being appended to; but popping that struct only pops once. However, qmp_ouput_add() was trying to either set up the added object as the new root (works if you parse two top-level scalars in a row: the second replaces the first as the root) or as a member of the current container (works as long as you have an open container on the stack; but if you have popped the first top-level container, it then resolves to the root and still tries to add into that existing container). Fix the stupidity by not tracking two separate things in the stack. Drop the now-useless qmp_output_first() and qmp_output_last() while at it. Saved for a later patch: we still are rather sloppy in that qmp_output_get_object() can be called in the middle of a parse, rather than requiring that a visit is complete. Backports commit 455ba08afde784466420449d01c6458f88349d55 from qemu
2018-02-20 13:09:55 +00:00
qlist_append_obj(qobject_to_qlist(cur), value);
break;
default:
g_assert_not_reached();
}
import
2015-08-21 07:04:50 +00:00
}
}
qapi: Swap 'name' in visit_* callbacks to match public API As explained in the previous patches, matching argument order of 'name, &value' to JSON's "name":value makes sense. However, while the last two patches were easy with Coccinelle, I ended up doing this one all by hand. Now all the visitor callbacks match the main interface. The compiler is able to enforce that all clients match the changed interface in visitor-impl.h, even where two pointers are being swapped, because only one of the two pointers is const (if that were not the case, then C's looseness on treating 'char *' like 'void *' would have made review a bit harder). Backports commit 0b2a0d6bb2446060944061e53e87d0c7addede79 from qemu
2018-02-20 04:28:33 +00:00
static void qmp_output_start_struct(Visitor *v, const char *name, void **obj,
qapi: Drop unused 'kind' for struct/enum visit visit_start_struct() and visit_type_enum() had a 'kind' argument that was usually set to either the stringized version of the corresponding qapi type name, or to NULL (although some clients didn't even get that right). But nothing ever used the argument. It's even hard to argue that it would be useful in a debugger, as a stack backtrace also tells which type is being visited. Therefore, drop the 'kind' argument as dead. Backports commit 337283dffbb5ad5860ed00408a5fd0665c21be07 from qemu
2018-02-20 04:42:59 +00:00
size_t unused, Error **errp)
import
2015-08-21 07:04:50 +00:00
{
QmpOutputVisitor *qov = to_qov(v);
QDict *dict = qdict_new();
qmp_output_add(qov, name, dict);
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
qmp_output_push(qov, dict, obj);
import
2015-08-21 07:04:50 +00:00
}
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
static void qmp_output_end_struct(Visitor *v, void **obj)
import
2015-08-21 07:04:50 +00:00
{
QmpOutputVisitor *qov = to_qov(v);
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
QObject *value = qmp_output_pop(qov, obj);
qmp: Tighten output visitor rules Tighten assertions in the QMP output visitor, so that: - qmp_output_get_qobject() can only be called after pairing a visit_end_* for every visit_start_* (rather than allowing it on a partially built object) - qmp_output_get_qobject() cannot be called unless at least one visit_type_* or visit_start/visit_end pair has occurred since creation/reset (the accidental return of NULL fixed by commit ab8bf1d7 would have been much easier to diagnose) - ensure that we are encountering the expected object or list type, to provide protection against mismatched push(struct)/ pop(list) or push(list)/pop(struct), similar to the qmp-input protection added in commit bdd8e6b5. - ensure that except for the root, 'name' is non-null inside a dict, and NULL inside a list (this may need changing later if we add "name.0" support for better error messages for a list, but for now it makes sure all users are at least consistent) Backports commit 56a6f02b8ce1fe41a2a9077593e46eca7d98267d from qemu
2018-02-24 00:04:38 +00:00
assert(qobject_type(value) == QTYPE_QDICT);
import
2015-08-21 07:04:50 +00:00
}
qapi: Simplify semantics of visit_next_list() The semantics of the list visit are somewhat baroque, with the following pseudocode when FooList is used: start() for (prev = head; cur = next(prev); prev = &cur) { visit(&cur->value) } Note that these semantics (advance before visit) requires that the first call to next() return the list head, while all other calls return the next element of the list; that is, every visitor implementation is required to track extra state to decide whether to return the input as-is, or to advance. It also requires an argument of 'GenericList **' to next(), solely because the first iteration might need to modify the caller's GenericList head, so that all other calls have to do a layer of dereferencing. Thankfully, we only have two uses of list visits in the entire code base: one in spapr_drc (which completely avoids visit_next_list(), feeding in integers from a different source than uint8List), and one in qapi-visit.py. That is, all other list visitors are generated in qapi-visit.c, and share the same paradigm based on a qapi FooList type, so we can refactor how lists are laid out with minimal churn among clients. We can greatly simplify things by hoisting the special case into the start() routine, and flipping the order in the loop to visit before advance: start(head) for (tail = *head; tail; tail = next(tail)) { visit(&tail->value) } With the simpler semantics, visitors have less state to track, the argument to next() is reduced to 'GenericList *', and it also becomes obvious whether an input visitor is allocating a FooList during visit_start_list() (rather than the old way of not knowing if an allocation happened until the first visit_next_list()). As a minor drawback, we now allocate in two functions instead of one, and have to pass the size to both functions (unless we were to tweak the input visitors to cache the size to start_list for reuse during next_list, but that defeats the goal of less visitor state). The signature of visit_start_list() is chosen to match visit_start_struct(), with the new parameters after 'name'. The spapr_drc case is a virtual visit, done by passing NULL for list, similarly to how NULL is passed to visit_start_struct() when a qapi type is not used in those visits. It was easy to provide these semantics for qmp-output and dealloc visitors, and a bit harder for qmp-input (several prerequisite patches refactored things to make this patch straightforward). But it turned out that the string and opts visitors munge enough other state during visit_next_list() to make it easier to just document and require a GenericList visit for now; an assertion will remind us to adjust things if we need the semantics in the future. Several pre-requisite cleanup patches made the reshuffling of the various visitors easier; particularly the qmp input visitor. Backports commit d9f62dde1303286b24ac8ce88be27e2b9b9c5f46 from qemu
2018-02-24 00:44:26 +00:00
static void qmp_output_start_list(Visitor *v, const char *name,
GenericList **listp, size_t size,
Error **errp)
import
2015-08-21 07:04:50 +00:00
{
QmpOutputVisitor *qov = to_qov(v);
QList *list = qlist_new();
qmp_output_add(qov, name, list);
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
qmp_output_push(qov, list, listp);
import
2015-08-21 07:04:50 +00:00
}
qapi: Simplify semantics of visit_next_list() The semantics of the list visit are somewhat baroque, with the following pseudocode when FooList is used: start() for (prev = head; cur = next(prev); prev = &cur) { visit(&cur->value) } Note that these semantics (advance before visit) requires that the first call to next() return the list head, while all other calls return the next element of the list; that is, every visitor implementation is required to track extra state to decide whether to return the input as-is, or to advance. It also requires an argument of 'GenericList **' to next(), solely because the first iteration might need to modify the caller's GenericList head, so that all other calls have to do a layer of dereferencing. Thankfully, we only have two uses of list visits in the entire code base: one in spapr_drc (which completely avoids visit_next_list(), feeding in integers from a different source than uint8List), and one in qapi-visit.py. That is, all other list visitors are generated in qapi-visit.c, and share the same paradigm based on a qapi FooList type, so we can refactor how lists are laid out with minimal churn among clients. We can greatly simplify things by hoisting the special case into the start() routine, and flipping the order in the loop to visit before advance: start(head) for (tail = *head; tail; tail = next(tail)) { visit(&tail->value) } With the simpler semantics, visitors have less state to track, the argument to next() is reduced to 'GenericList *', and it also becomes obvious whether an input visitor is allocating a FooList during visit_start_list() (rather than the old way of not knowing if an allocation happened until the first visit_next_list()). As a minor drawback, we now allocate in two functions instead of one, and have to pass the size to both functions (unless we were to tweak the input visitors to cache the size to start_list for reuse during next_list, but that defeats the goal of less visitor state). The signature of visit_start_list() is chosen to match visit_start_struct(), with the new parameters after 'name'. The spapr_drc case is a virtual visit, done by passing NULL for list, similarly to how NULL is passed to visit_start_struct() when a qapi type is not used in those visits. It was easy to provide these semantics for qmp-output and dealloc visitors, and a bit harder for qmp-input (several prerequisite patches refactored things to make this patch straightforward). But it turned out that the string and opts visitors munge enough other state during visit_next_list() to make it easier to just document and require a GenericList visit for now; an assertion will remind us to adjust things if we need the semantics in the future. Several pre-requisite cleanup patches made the reshuffling of the various visitors easier; particularly the qmp input visitor. Backports commit d9f62dde1303286b24ac8ce88be27e2b9b9c5f46 from qemu
2018-02-24 00:44:26 +00:00
static GenericList *qmp_output_next_list(Visitor *v, GenericList *tail,
qapi: Adjust layout of FooList types By sticking the next pointer first, we don't need a union with 64-bit padding for smaller types. On 32-bit platforms, this can reduce the size of uint8List from 16 bytes (or 12, depending on whether 64-bit ints can tolerate 4-byte alignment) down to 8. It has no effect on 64-bit platforms (where alignment still dictates a 16-byte struct); but fewer anonymous unions is still a win in my book. It requires visit_next_list() to gain a size parameter, to know what size element to allocate; comparable to the size parameter of visit_start_struct(). I debated about going one step further, to allow for fewer casts, by doing: typedef GenericList GenericList; struct GenericList { GenericList *next; }; struct FooList { GenericList base; Foo *value; }; so that you convert to 'GenericList *' by '&foolist->base', and back by 'container_of(generic, GenericList, base)' (as opposed to the existing '(GenericList *)foolist' and '(FooList *)generic'). But doing that would require hoisting the declaration of GenericList prior to inclusion of qapi-types.h, rather than its current spot in visitor.h; it also makes iteration a bit more verbose through 'foolist->base.next' instead of 'foolist->next'. Note that for lists of objects, the 'value' payload is still hidden behind a boxed pointer. Someday, it would be nice to do: struct FooList { FooList *next; Foo value; }; for one less level of malloc for each list element. This patch is a step in that direction (now that 'next' is no longer at a fixed non-zero offset within the struct, we can store more than just a pointer's-worth of data as the value payload), but the actual conversion would be a task for another series, as it will touch a lot of code. Backports commit e65d89bf1a4484e0db0f3dc820a8b209f2fb1e8b from qemu
2018-02-23 19:48:57 +00:00
size_t size)
import
2015-08-21 07:04:50 +00:00
{
qapi: Simplify semantics of visit_next_list() The semantics of the list visit are somewhat baroque, with the following pseudocode when FooList is used: start() for (prev = head; cur = next(prev); prev = &cur) { visit(&cur->value) } Note that these semantics (advance before visit) requires that the first call to next() return the list head, while all other calls return the next element of the list; that is, every visitor implementation is required to track extra state to decide whether to return the input as-is, or to advance. It also requires an argument of 'GenericList **' to next(), solely because the first iteration might need to modify the caller's GenericList head, so that all other calls have to do a layer of dereferencing. Thankfully, we only have two uses of list visits in the entire code base: one in spapr_drc (which completely avoids visit_next_list(), feeding in integers from a different source than uint8List), and one in qapi-visit.py. That is, all other list visitors are generated in qapi-visit.c, and share the same paradigm based on a qapi FooList type, so we can refactor how lists are laid out with minimal churn among clients. We can greatly simplify things by hoisting the special case into the start() routine, and flipping the order in the loop to visit before advance: start(head) for (tail = *head; tail; tail = next(tail)) { visit(&tail->value) } With the simpler semantics, visitors have less state to track, the argument to next() is reduced to 'GenericList *', and it also becomes obvious whether an input visitor is allocating a FooList during visit_start_list() (rather than the old way of not knowing if an allocation happened until the first visit_next_list()). As a minor drawback, we now allocate in two functions instead of one, and have to pass the size to both functions (unless we were to tweak the input visitors to cache the size to start_list for reuse during next_list, but that defeats the goal of less visitor state). The signature of visit_start_list() is chosen to match visit_start_struct(), with the new parameters after 'name'. The spapr_drc case is a virtual visit, done by passing NULL for list, similarly to how NULL is passed to visit_start_struct() when a qapi type is not used in those visits. It was easy to provide these semantics for qmp-output and dealloc visitors, and a bit harder for qmp-input (several prerequisite patches refactored things to make this patch straightforward). But it turned out that the string and opts visitors munge enough other state during visit_next_list() to make it easier to just document and require a GenericList visit for now; an assertion will remind us to adjust things if we need the semantics in the future. Several pre-requisite cleanup patches made the reshuffling of the various visitors easier; particularly the qmp input visitor. Backports commit d9f62dde1303286b24ac8ce88be27e2b9b9c5f46 from qemu
2018-02-24 00:44:26 +00:00
return tail->next;
import
2015-08-21 07:04:50 +00:00
}
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
static void qmp_output_end_list(Visitor *v, void **obj)
import
2015-08-21 07:04:50 +00:00
{
QmpOutputVisitor *qov = to_qov(v);
qapi: Add parameter to visit_end_* Rather than making the dealloc visitor track of stack of pointers remembered during visit_start_* in order to free them during visit_end_*, it's a lot easier to just make all callers pass the same pointer to visit_end_*. The generated code has access to the same pointer, while all other users are doing virtual walks and can pass NULL. The dealloc visitor is then greatly simplified. All three visit_end_*() functions intentionally take a void**, even though the visit_start_*() functions differ between void**, GenericList**, and GenericAlternate**. This is done for several reasons: when doing a virtual walk, passing NULL doesn't care what the type is, but when doing a generated walk, we already have to cast the caller's specific FOO* to call visit_start, while using void** lets us use visit_end without a cast. Also, an upcoming patch will add a clone visitor that wants to use the same implementation for all three visit_end callbacks, which is made easier if all three share the same signature. For visitors with already track per-object state (the QMP visitors via a stack, and the string visitors which do not allow nesting), add an assertion that the caller is indeed passing the same pointer to paired calls. Backports commit 1158bb2a058fcdd0c8fc3e60dc77f7a57ddbb271 from qemu
2018-02-25 05:53:31 +00:00
QObject *value = qmp_output_pop(qov, obj);
qmp: Tighten output visitor rules Tighten assertions in the QMP output visitor, so that: - qmp_output_get_qobject() can only be called after pairing a visit_end_* for every visit_start_* (rather than allowing it on a partially built object) - qmp_output_get_qobject() cannot be called unless at least one visit_type_* or visit_start/visit_end pair has occurred since creation/reset (the accidental return of NULL fixed by commit ab8bf1d7 would have been much easier to diagnose) - ensure that we are encountering the expected object or list type, to provide protection against mismatched push(struct)/ pop(list) or push(list)/pop(struct), similar to the qmp-input protection added in commit bdd8e6b5. - ensure that except for the root, 'name' is non-null inside a dict, and NULL inside a list (this may need changing later if we add "name.0" support for better error messages for a list, but for now it makes sure all users are at least consistent) Backports commit 56a6f02b8ce1fe41a2a9077593e46eca7d98267d from qemu
2018-02-24 00:04:38 +00:00
assert(qobject_type(value) == QTYPE_QLIST);
import
2015-08-21 07:04:50 +00:00
}
qapi: Swap 'name' in visit_* callbacks to match public API As explained in the previous patches, matching argument order of 'name, &value' to JSON's "name":value makes sense. However, while the last two patches were easy with Coccinelle, I ended up doing this one all by hand. Now all the visitor callbacks match the main interface. The compiler is able to enforce that all clients match the changed interface in visitor-impl.h, even where two pointers are being swapped, because only one of the two pointers is const (if that were not the case, then C's looseness on treating 'char *' like 'void *' would have made review a bit harder). Backports commit 0b2a0d6bb2446060944061e53e87d0c7addede79 from qemu
2018-02-20 04:28:33 +00:00
static void qmp_output_type_int64(Visitor *v, const char *name, int64_t *obj,
qapi: Prefer type_int64 over type_int in visitors The qapi builtin type 'int' is basically shorthand for the type 'int64'. In fact, since no visitor was providing the optional type_int64() callback, visit_type_int64() was just always falling back to type_int(), cementing the equivalence between the types. However, some visitors are providing a type_uint64() callback. For purposes of code consistency, it is nicer if all visitors use the paired type_int64/type_uint64 names rather than the mismatched type_int/type_uint64. So this patch just renames the signed int callbacks in place, dropping the type_int() callback as redundant, and a later patch will focus on the unsigned int callbacks. Add some FIXMEs to questionable reuse of errp in code touched by the rename, while at it (the reuse works as long as the callbacks don't modify value when setting an error, but it's not a good example to set) - a later patch will then fix those. No change in functionality here, although further cleanups are in the pipeline. Backports commit 4c40314a35816de635e7170eaacdc0c35be83a8a from qemu
2018-02-19 16:53:19 +00:00
Error **errp)
import
2015-08-21 07:04:50 +00:00
{
QmpOutputVisitor *qov = to_qov(v);
qmp_output_add(qov, name, qint_from_int(*obj));
}
qapi: Swap 'name' in visit_* callbacks to match public API As explained in the previous patches, matching argument order of 'name, &value' to JSON's "name":value makes sense. However, while the last two patches were easy with Coccinelle, I ended up doing this one all by hand. Now all the visitor callbacks match the main interface. The compiler is able to enforce that all clients match the changed interface in visitor-impl.h, even where two pointers are being swapped, because only one of the two pointers is const (if that were not the case, then C's looseness on treating 'char *' like 'void *' would have made review a bit harder). Backports commit 0b2a0d6bb2446060944061e53e87d0c7addede79 from qemu
2018-02-20 04:28:33 +00:00
static void qmp_output_type_uint64(Visitor *v, const char *name, uint64_t *obj,
qapi: Make all visitors supply uint64 callbacks Our qapi visitor contract supports multiple integer visitors, but left the type_uint64 visitor as optional (falling back on type_int64); which in turn can lead to awkward behavior with numbers larger than INT64_MAX (the user has to be aware of twos complement, and deal with negatives). This patch does not address the disparity in handling large values as negatives. It merely moves the fallback from uint64 to int64 from the visitor core to the visitors, where the issue can actually be fixed, by implementing the missing type_uint64() callbacks on top of the respective type_int64() callbacks, and with a FIXME comment explaining why that's wrong. With that done, we now have a type_uint64() callback in every driver, so we can make it mandatory from the core. And although the type_int64() callback can cover the entire valid range of type_uint{8,16,32} on valid user input, using type_uint64() to avoid mixed signedness makes more sense. Backports commit f755dea79dc81b0d6a8f6414e0672e165e28d8ba from qemu
2018-02-19 16:57:56 +00:00
Error **errp)
{
/* FIXME: QMP outputs values larger than INT64_MAX as negative */
QmpOutputVisitor *qov = to_qov(v);
qmp_output_add(qov, name, qint_from_int(*obj));
}
qapi: Swap 'name' in visit_* callbacks to match public API As explained in the previous patches, matching argument order of 'name, &value' to JSON's "name":value makes sense. However, while the last two patches were easy with Coccinelle, I ended up doing this one all by hand. Now all the visitor callbacks match the main interface. The compiler is able to enforce that all clients match the changed interface in visitor-impl.h, even where two pointers are being swapped, because only one of the two pointers is const (if that were not the case, then C's looseness on treating 'char *' like 'void *' would have made review a bit harder). Backports commit 0b2a0d6bb2446060944061e53e87d0c7addede79 from qemu
2018-02-20 04:28:33 +00:00
static void qmp_output_type_bool(Visitor *v, const char *name, bool *obj,
import
2015-08-21 07:04:50 +00:00
Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
qobject: Use 'bool' for qbool We require a C99 compiler, so let's use 'bool' instead of 'int' when dealing with boolean values. There are few enough clients to fix them all in one pass. Backports commit fc48ffc39ed1060856475e4320d5896f26c945e8 from qemu
2018-02-13 22:13:24 +00:00
qmp_output_add(qov, name, qbool_from_bool(*obj));
import
2015-08-21 07:04:50 +00:00
}
qapi: Swap 'name' in visit_* callbacks to match public API As explained in the previous patches, matching argument order of 'name, &value' to JSON's "name":value makes sense. However, while the last two patches were easy with Coccinelle, I ended up doing this one all by hand. Now all the visitor callbacks match the main interface. The compiler is able to enforce that all clients match the changed interface in visitor-impl.h, even where two pointers are being swapped, because only one of the two pointers is const (if that were not the case, then C's looseness on treating 'char *' like 'void *' would have made review a bit harder). Backports commit 0b2a0d6bb2446060944061e53e87d0c7addede79 from qemu
2018-02-20 04:28:33 +00:00
static void qmp_output_type_str(Visitor *v, const char *name, char **obj,
import
2015-08-21 07:04:50 +00:00
Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
if (*obj) {
qmp_output_add(qov, name, qstring_from_str(*obj));
} else {
qmp_output_add(qov, name, qstring_from_str(""));
}
}
qapi: Swap 'name' in visit_* callbacks to match public API As explained in the previous patches, matching argument order of 'name, &value' to JSON's "name":value makes sense. However, while the last two patches were easy with Coccinelle, I ended up doing this one all by hand. Now all the visitor callbacks match the main interface. The compiler is able to enforce that all clients match the changed interface in visitor-impl.h, even where two pointers are being swapped, because only one of the two pointers is const (if that were not the case, then C's looseness on treating 'char *' like 'void *' would have made review a bit harder). Backports commit 0b2a0d6bb2446060944061e53e87d0c7addede79 from qemu
2018-02-20 04:28:33 +00:00
static void qmp_output_type_number(Visitor *v, const char *name, double *obj,
import
2015-08-21 07:04:50 +00:00
Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
qmp_output_add(qov, name, qfloat_from_double(*obj));
}
qapi: Swap 'name' in visit_* callbacks to match public API As explained in the previous patches, matching argument order of 'name, &value' to JSON's "name":value makes sense. However, while the last two patches were easy with Coccinelle, I ended up doing this one all by hand. Now all the visitor callbacks match the main interface. The compiler is able to enforce that all clients match the changed interface in visitor-impl.h, even where two pointers are being swapped, because only one of the two pointers is const (if that were not the case, then C's looseness on treating 'char *' like 'void *' would have made review a bit harder). Backports commit 0b2a0d6bb2446060944061e53e87d0c7addede79 from qemu
2018-02-20 04:28:33 +00:00
static void qmp_output_type_any(Visitor *v, const char *name, QObject **obj,
qapi: Introduce a first class 'any' type It's first class, because unlike '**', it actually works, i.e. doesn't require 'gen': false. '**' will go away next. Backports commit 28770e057f265a4e70bcbdfc2447cce7b5f2dc19 from qemu
2018-02-19 22:45:25 +00:00
Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
qobject_incref(*obj);
qmp_output_add_obj(qov, name, *obj);
}
qapi: Add visit_type_null() visitor Right now, qmp-output-visitor happens to produce a QNull result if nothing is actually visited between the creation of the visitor and the request for the resulting QObject. A stronger protocol would require that a QMP output visit MUST visit something. But to still be able to produce a JSON 'null' output, we need a new visitor function that states our intentions. Yes, we could say that such a visit must go through visit_type_any(), but that feels clunky. So this patch introduces the new visit_type_null() interface and its no-op interface in the dealloc visitor, and stubs in the qmp visitors (the next patch will finish the implementation). For the visitors that will not implement the callback, document the situation. The code in qapi-visit-core unconditionally dereferences the callback pointer, so that a segfault will inform a developer if they need to implement the callback for their choice of visitor. Note that JSON has a primitive null type, with the single value null; likewise with the QNull type for QObject; but for QAPI, we just have the 'null' value without a null type. We may eventually want to add more support in QAPI for null (most likely, we'd use it via an alternate type that permits 'null' or an object); but we'll create that usage when we need it. Backports commit 3bc97fd5924561d92f32758c67eaffd2e4e25038 from qemu
2018-02-23 20:48:53 +00:00
static void qmp_output_type_null(Visitor *v, const char *name, Error **errp)
{
qmp: Support explicit null during visits Implement the new type_null() callback for the qmp input and output visitors. While we don't yet have a use for this in QAPI input (the generator will need some tweaks first), some potential usages have already been discussed on the list. Meanwhile, the output visitor could already output explicit null via type_any, but this gives us finer control. At any rate, it's easy to test that we can round-trip an explicit null through manual use of visit_type_null() wrapped by a virtual visit_start_struct() walk, even if we can't do the visit in a QAPI type. Repurpose the test_visitor_out_empty test, particularly since a future patch will tighten semantics to forbid use of qmp_output_get_qobject() without at least one intervening visit_type_*. Backports commit 3df016f185521f8dfa5bd89168722887156405c7 from qemu
2018-02-24 00:02:11 +00:00
QmpOutputVisitor *qov = to_qov(v);
qmp_output_add_obj(qov, name, qnull());
qapi: Add visit_type_null() visitor Right now, qmp-output-visitor happens to produce a QNull result if nothing is actually visited between the creation of the visitor and the request for the resulting QObject. A stronger protocol would require that a QMP output visit MUST visit something. But to still be able to produce a JSON 'null' output, we need a new visitor function that states our intentions. Yes, we could say that such a visit must go through visit_type_any(), but that feels clunky. So this patch introduces the new visit_type_null() interface and its no-op interface in the dealloc visitor, and stubs in the qmp visitors (the next patch will finish the implementation). For the visitors that will not implement the callback, document the situation. The code in qapi-visit-core unconditionally dereferences the callback pointer, so that a segfault will inform a developer if they need to implement the callback for their choice of visitor. Note that JSON has a primitive null type, with the single value null; likewise with the QNull type for QObject; but for QAPI, we just have the 'null' value without a null type. We may eventually want to add more support in QAPI for null (most likely, we'd use it via an alternate type that permits 'null' or an object); but we'll create that usage when we need it. Backports commit 3bc97fd5924561d92f32758c67eaffd2e4e25038 from qemu
2018-02-23 20:48:53 +00:00
}
qmp: Tighten output visitor rules Tighten assertions in the QMP output visitor, so that: - qmp_output_get_qobject() can only be called after pairing a visit_end_* for every visit_start_* (rather than allowing it on a partially built object) - qmp_output_get_qobject() cannot be called unless at least one visit_type_* or visit_start/visit_end pair has occurred since creation/reset (the accidental return of NULL fixed by commit ab8bf1d7 would have been much easier to diagnose) - ensure that we are encountering the expected object or list type, to provide protection against mismatched push(struct)/ pop(list) or push(list)/pop(struct), similar to the qmp-input protection added in commit bdd8e6b5. - ensure that except for the root, 'name' is non-null inside a dict, and NULL inside a list (this may need changing later if we add "name.0" support for better error messages for a list, but for now it makes sure all users are at least consistent) Backports commit 56a6f02b8ce1fe41a2a9077593e46eca7d98267d from qemu
2018-02-24 00:04:38 +00:00
/* Finish building, and return the root object.
* The root object is never null. The caller becomes the object's
* owner, and should use qobject_decref() when done with it. */
import
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QObject *qmp_output_get_qobject(QmpOutputVisitor *qov)
{
qmp: Tighten output visitor rules Tighten assertions in the QMP output visitor, so that: - qmp_output_get_qobject() can only be called after pairing a visit_end_* for every visit_start_* (rather than allowing it on a partially built object) - qmp_output_get_qobject() cannot be called unless at least one visit_type_* or visit_start/visit_end pair has occurred since creation/reset (the accidental return of NULL fixed by commit ab8bf1d7 would have been much easier to diagnose) - ensure that we are encountering the expected object or list type, to provide protection against mismatched push(struct)/ pop(list) or push(list)/pop(struct), similar to the qmp-input protection added in commit bdd8e6b5. - ensure that except for the root, 'name' is non-null inside a dict, and NULL inside a list (this may need changing later if we add "name.0" support for better error messages for a list, but for now it makes sure all users are at least consistent) Backports commit 56a6f02b8ce1fe41a2a9077593e46eca7d98267d from qemu
2018-02-24 00:04:38 +00:00
/* A visit must have occurred, with each start paired with end. */
assert(qov->root && QTAILQ_EMPTY(&qov->stack));
qobject_incref(qov->root);
return qov->root;
import
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}
Visitor *qmp_output_get_visitor(QmpOutputVisitor *v)
{
return &v->visitor;
}
qapi: Add new visit_free() function Making each visitor provide its own (awkwardly-named) FOO_cleanup() is unusual, when we can instead have a polymorphic visit_free() interface. Over the next few patches, we can use the polymorphic functions to eliminate the need for a FOO_get_visitor() function for accessing specific visitor functionality, once everything can be accessed directly through the Visitor* interfaces. The dealloc visitor is the first one converted to completely use the new entry point, since qapi_dealloc_visitor_cleanup() was the only reason that qapi_dealloc_get_visitor() existed, and only generated and testsuite code was even using it. With the new visit_free() entry point in place, we no longer need to expose the QapiDeallocVisitor subtype through qapi_dealloc_visitor_new(), and can get by with less generated code, with diffs that look like: | void qapi_free_ACPIOSTInfo(ACPIOSTInfo *obj) | { |- QapiDeallocVisitor *qdv; | Visitor *v; | | if (!obj) { | return; | } | |- qdv = qapi_dealloc_visitor_new(); |- v = qapi_dealloc_get_visitor(qdv); |+ v = qapi_dealloc_visitor_new(); | visit_type_ACPIOSTInfo(v, NULL, &obj, NULL); |- qapi_dealloc_visitor_cleanup(qdv); |+ visit_free(v); |} Backports commit 2c0ef9f411ae6081efa9eca5b3eab2dbeee45a6c from qemu
2018-02-25 06:02:56 +00:00
static void qmp_output_free(Visitor *v)
{
QmpOutputVisitor *qov = to_qov(v);
import
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QStackEntry *e, *tmp;
qmp-output-visitor: Favor new visit_free() function Now that we have a polymorphic visit_free(), we no longer need qmp_output_visitor_cleanup(); however, we still need to expose the subtype for qmp_output_get_qobject(). Backports commit 1830f22a6777cedaccd67a08f675d30f7a85ebfd from qemu
2018-02-25 06:12:22 +00:00
QTAILQ_FOREACH_SAFE(e, &qov->stack, node, tmp) {
QTAILQ_REMOVE(&qov->stack, e, node);
revert to use of g_free to make future qemu integrations easier (#695) * revert to use of g_free to make future qemu integrations easier * bracing
2016-12-21 14:28:36 +00:00
g_free(e);
import
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}
qmp-output-visitor: Favor new visit_free() function Now that we have a polymorphic visit_free(), we no longer need qmp_output_visitor_cleanup(); however, we still need to expose the subtype for qmp_output_get_qobject(). Backports commit 1830f22a6777cedaccd67a08f675d30f7a85ebfd from qemu
2018-02-25 06:12:22 +00:00
qobject_decref(qov->root);
g_free(qov);
import
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}
QmpOutputVisitor *qmp_output_visitor_new(void)
{
QmpOutputVisitor *v;
v = g_malloc0(sizeof(*v));
qapi-visit: Add visitor.type classification We have three classes of QAPI visitors: input, output, and dealloc. Currently, all implementations of these visitors have one thing in common based on their visitor type: the implementation used for the visit_type_enum() callback. But since we plan to add more such common behavior, in relation to documenting and further refining the semantics, it makes more sense to have the visitor implementations advertise which class they belong to, so the common qapi-visit-core code can use that information in multiple places. A later patch will better document the types of visitors directly in visitor.h. For this patch, knowing the class of a visitor implementation lets us make input_type_enum() and output_type_enum() become static functions, by replacing the callback function Visitor.type_enum() with the simpler enum member Visitor.type. Share a common assertion in qapi-visit-core as part of the refactoring. Move comments in opts-visitor.c to match the refactored layout. Backports commit 983f52d4b3f86fb9dc9f8b142132feb5a8723016 from qemu
2018-02-23 19:25:19 +00:00
v->visitor.type = VISITOR_OUTPUT;
import
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v->visitor.start_struct = qmp_output_start_struct;
v->visitor.end_struct = qmp_output_end_struct;
v->visitor.start_list = qmp_output_start_list;
v->visitor.next_list = qmp_output_next_list;
v->visitor.end_list = qmp_output_end_list;
qapi: Prefer type_int64 over type_int in visitors The qapi builtin type 'int' is basically shorthand for the type 'int64'. In fact, since no visitor was providing the optional type_int64() callback, visit_type_int64() was just always falling back to type_int(), cementing the equivalence between the types. However, some visitors are providing a type_uint64() callback. For purposes of code consistency, it is nicer if all visitors use the paired type_int64/type_uint64 names rather than the mismatched type_int/type_uint64. So this patch just renames the signed int callbacks in place, dropping the type_int() callback as redundant, and a later patch will focus on the unsigned int callbacks. Add some FIXMEs to questionable reuse of errp in code touched by the rename, while at it (the reuse works as long as the callbacks don't modify value when setting an error, but it's not a good example to set) - a later patch will then fix those. No change in functionality here, although further cleanups are in the pipeline. Backports commit 4c40314a35816de635e7170eaacdc0c35be83a8a from qemu
2018-02-19 16:53:19 +00:00
v->visitor.type_int64 = qmp_output_type_int64;
qapi: Make all visitors supply uint64 callbacks Our qapi visitor contract supports multiple integer visitors, but left the type_uint64 visitor as optional (falling back on type_int64); which in turn can lead to awkward behavior with numbers larger than INT64_MAX (the user has to be aware of twos complement, and deal with negatives). This patch does not address the disparity in handling large values as negatives. It merely moves the fallback from uint64 to int64 from the visitor core to the visitors, where the issue can actually be fixed, by implementing the missing type_uint64() callbacks on top of the respective type_int64() callbacks, and with a FIXME comment explaining why that's wrong. With that done, we now have a type_uint64() callback in every driver, so we can make it mandatory from the core. And although the type_int64() callback can cover the entire valid range of type_uint{8,16,32} on valid user input, using type_uint64() to avoid mixed signedness makes more sense. Backports commit f755dea79dc81b0d6a8f6414e0672e165e28d8ba from qemu
2018-02-19 16:57:56 +00:00
v->visitor.type_uint64 = qmp_output_type_uint64;
import
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v->visitor.type_bool = qmp_output_type_bool;
v->visitor.type_str = qmp_output_type_str;
v->visitor.type_number = qmp_output_type_number;
qapi: Introduce a first class 'any' type It's first class, because unlike '**', it actually works, i.e. doesn't require 'gen': false. '**' will go away next. Backports commit 28770e057f265a4e70bcbdfc2447cce7b5f2dc19 from qemu
2018-02-19 22:45:25 +00:00
v->visitor.type_any = qmp_output_type_any;
qapi: Add visit_type_null() visitor Right now, qmp-output-visitor happens to produce a QNull result if nothing is actually visited between the creation of the visitor and the request for the resulting QObject. A stronger protocol would require that a QMP output visit MUST visit something. But to still be able to produce a JSON 'null' output, we need a new visitor function that states our intentions. Yes, we could say that such a visit must go through visit_type_any(), but that feels clunky. So this patch introduces the new visit_type_null() interface and its no-op interface in the dealloc visitor, and stubs in the qmp visitors (the next patch will finish the implementation). For the visitors that will not implement the callback, document the situation. The code in qapi-visit-core unconditionally dereferences the callback pointer, so that a segfault will inform a developer if they need to implement the callback for their choice of visitor. Note that JSON has a primitive null type, with the single value null; likewise with the QNull type for QObject; but for QAPI, we just have the 'null' value without a null type. We may eventually want to add more support in QAPI for null (most likely, we'd use it via an alternate type that permits 'null' or an object); but we'll create that usage when we need it. Backports commit 3bc97fd5924561d92f32758c67eaffd2e4e25038 from qemu
2018-02-23 20:48:53 +00:00
v->visitor.type_null = qmp_output_type_null;
qapi: Add new visit_free() function Making each visitor provide its own (awkwardly-named) FOO_cleanup() is unusual, when we can instead have a polymorphic visit_free() interface. Over the next few patches, we can use the polymorphic functions to eliminate the need for a FOO_get_visitor() function for accessing specific visitor functionality, once everything can be accessed directly through the Visitor* interfaces. The dealloc visitor is the first one converted to completely use the new entry point, since qapi_dealloc_visitor_cleanup() was the only reason that qapi_dealloc_get_visitor() existed, and only generated and testsuite code was even using it. With the new visit_free() entry point in place, we no longer need to expose the QapiDeallocVisitor subtype through qapi_dealloc_visitor_new(), and can get by with less generated code, with diffs that look like: | void qapi_free_ACPIOSTInfo(ACPIOSTInfo *obj) | { |- QapiDeallocVisitor *qdv; | Visitor *v; | | if (!obj) { | return; | } | |- qdv = qapi_dealloc_visitor_new(); |- v = qapi_dealloc_get_visitor(qdv); |+ v = qapi_dealloc_visitor_new(); | visit_type_ACPIOSTInfo(v, NULL, &obj, NULL); |- qapi_dealloc_visitor_cleanup(qdv); |+ visit_free(v); |} Backports commit 2c0ef9f411ae6081efa9eca5b3eab2dbeee45a6c from qemu
2018-02-25 06:02:56 +00:00
v->visitor.free = qmp_output_free;
import
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QTAILQ_INIT(&v->stack);
return v;
}
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