To be more accurate on its purpose and make code that looks for a certain
target out of this variable more readable.
Backports commit 208ecb3e1acc8d55dab49fdf721a86d513691688 from qemu
move tcg-runtime.c, translate-all.(ch) and translate-common.c into
accel/tcg/ subdirectory and updated related trace-events file.
Backports commit 244f144134d0dd182f1af8654e7f9a79fe770368 and applies
relevant changes made in db432672dc50ed86dda17ac821b7eb07411a90af and
d9bb58e51068dfc48746c6af0179926c8dc05bce from qemu
Move qapi-schema.json to qapi/, so it's next to its modules, and all
files get generated to qapi/, not just the ones generated for modules.
Consistently name the generated files qapi-MODULE.EXT:
qmp-commands.[ch] become qapi-commands.[ch], qapi-event.[ch] become
qapi-events.[ch], and qmp-introspect.[ch] become qapi-introspect.[ch].
This gets rid of the temporary hacks in scripts/qapi/commands.py,
scripts/qapi/events.py, and scripts/qapi/common.py.
Backports commit eb815e248f50cde9ab86eddd57eca5019b71ca78 from qemu
The previous commit improved compile time by including less of the
generated QAPI headers. This is impossible for stuff defined directly
in qapi-schema.json, because that ends up in headers that that pull in
everything.
Move everything but include directives from qapi-schema.json to new
sub-module qapi/misc.json, then include just the "misc" shard where
possible.
It's possible everywhere, except:
* monitor.c needs qmp-command.h to get qmp_init_marshal()
* monitor.c, ui/vnc.c and the generated qapi-event-FOO.c need
qapi-event.h to get enum QAPIEvent
Perhaps we'll get rid of those some other day.
Adding a type to qapi/migration.json now recompiles some 120 instead
of 2300 out of 5100 objects.
Backports commit 112ed241f5d9a411dbca92bdf597151cb853c6a7 from qemu
Our qapi-schema.json is composed of modules connected by include
directives, but the generated code is monolithic all the same: one
qapi-types.h with all the types, one qapi-visit.h with all the
visitors, and so forth. These monolithic headers get included all
over the place. In my "build everything" tree, adding a QAPI type
recompiles about 4800 out of 5100 objects.
We wouldn't write such monolithic headers by hand. It stands to
reason that we shouldn't generate them, either.
Split up generated qapi-types.h to mirror the schema's modular
structure: one header per module. Name the main module's header
qapi-types.h, and sub-module D/B.json's header D/qapi-types-B.h.
Mirror the schema's includes in the headers, so that qapi-types.h gets
you everything exactly as before. If you need less, you can include
one or more of the sub-module headers. To be exploited shortly.
Split up qapi-types.c, qapi-visit.h, qapi-visit.c, qmp-commands.h,
qmp-commands.c, qapi-event.h, qapi-event.c the same way.
qmp-introspect.h, qmp-introspect.c and qapi.texi remain monolithic.
The split of qmp-commands.c duplicates static helper function
qmp_marshal_output_str() in qapi-commands-char.c and
qapi-commands-misc.c. This happens when commands returning the same
type occur in multiple modules. Not worth avoiding.
Since I'm going to rename qapi-event.[ch] to qapi-events.[ch], and
qmp-commands.[ch] to qapi-commands.[ch], name the shards that way
already, to reduce churn. This requires temporary hacks in
commands.py and events.py. Similarly, c_name() must temporarily
be taught to munge '/' in common.py. They'll go away with the rename.
Backports commit 252dc3105fc494182e236e97fe20f2d6b1d652cb from qemu
Linking code from multiple separate QAPI schemata into the same
program is possible, but involves some weirdness around built-in
types:
* We generate code for built-in types into .c only with option
--builtins. The user is responsible for generating code for exactly
one QAPI schema per program with --builtins.
* We generate code for built-in types into .h regardless of
--builtins, but guarded by #ifndef QAPI_VISIT_BUILTIN. Because all
copies of this code are exactly the same, including any combination
of these headers works.
Replace this contraption by something more conventional: generate code
for built-in types into their very own files: qapi-builtin-types.c,
qapi-builtin-visit.c, qapi-builtin-types.h, qapi-builtin-visit.h, but
only with --builtins. Obey --output-dir, but ignore --prefix for
them.
Make qapi-types.h include qapi-builtin-types.h. With multiple
schemata you now have multiple qapi-types.[ch], but only one
qapi-builtin-types.[ch]. Same for qapi-visit.[ch] and
qapi-builtin-visit.[ch].
Bonus: if all you need is built-in stuff, you can include a much
smaller header. To be exploited shortly.
Backports commit cdb6610ae4283720037bae2af1f78bd40eb5fe71 from qemu
Whenever qapi-schema.json changes, we run six programs eleven times to
update eleven files. Similar for qga/qapi-schema.json. This is
silly. Replace the six programs by a single program that spits out
all eleven files.
The programs become modules in new Python package qapi, along with the
helper library. This requires moving them to scripts/qapi/. While
moving them, consistently drop executable mode bits.
Backports commit fb0bc835e56b894cbc7236294921e5393c786ad8 from qemu
Using a local m68k floatx80_mod()
[copied from previous:
Written by Andreas Grabher for Previous, NeXT Computer Emulator.]
The quotient byte of the FPSR is updated with
the result of the operation.
Backports commit 591596b77a1872d0652e666271ca055e57ea1e21 from qemu
The main culprit here is bswap.h which pulled in softfloat.h so it
could use the types in its CPU_Float* and ldfl/stfql functions. As
bswap.h is very widely included this added a compile dependency every
time we touch softfloat.h. Move the typedefs for each float type into
their own file so we don't re-build the world every time we tweak the
main softfloat.h header.
Backports commit cfd88fc6f2722def193f5ef271381d8f6e2a2526 from qemu
qapi/qmp/types.h is a convenience header to include a number of
qapi/qmp/ headers. Since we rarely need all of the headers
qapi/qmp/types.h includes, we bypass it most of the time. Most of the
places that use it don't need all the headers, either.
Include the necessary headers directly, and drop qapi/qmp/types.h.
Backports commit 6b67395762a4c8b6ca94364e0a0f616a6470c46a from qemu
no logical change, only code movement (and fix a comment typo).
Backports commit 26aa3d9aecbb6fe9bce808a1d127191bdf3cc3d2 from qemu
Also backports commit 5502b66fc7d0bebd08b9b7017cb7e8b5261c3a2d
Dispense with TCGBackendData, as it has never been used for more than
holding a single pointer. Use a define in the cpu/tcg-target.h to
signal requirement for TCGLabelQemuLdst, so that we can drop the no-op
tcg-be-null.h stubs. Rename tcg-be-ldst.h to tcg-ldst.inc.c.
Backports commit 659ef5cbb893872d25e9d95191cc23b16546c8a1 from qemu
We would like to use a same QObject type to represent numbers, whether
they are int, uint, or floats. Getters will allow some compatibility
between the various types if the number fits other representations.
Add a few more tests while at it.
Backports commit 01b2ffcedd94ad7b42bc870e4c6936c87ad03429 from qemu
We'll be using the memory ordering definitions to define values for
both the host and guest. To avoid fighting with circular header
dependencies just move these types into their own minimal header.
Backports commit 20937143145b8f5a4194e5c407731ba38797864e from qemu
Split ARM on/off function from PSCI support code.
This will allow to reuse these functions in other code.
Backports commit 825482adde1f971cbddf27e15fb4453ab3fae994 from qemu
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.
Backports commit fcf5ef2ab52c621a4617ebbef36bf43b4003f4c0 from qemu
The QMP visitors have no direct dependency on QMP. It is
valid to use them anywhere that one has a QObject. Rename them
to better reflect their functionality as a generic QObject
to QAPI converter.
This is the first of three parts: rename the files. The next two
parts will rename C identifiers. The split is necessary to make git
rename detection work.
Backports commit b3db211f3c80bb996a704d665fe275619f728bd4 from qemu
We have a couple places in the code base that want to deep-clone
one QAPI object into another, and they were resorting to serializing
the struct out to QObject then reparsing it. A much more efficient
version can be done by adding a new clone visitor.
Since cloning is still relatively uncommon, expose the use of the
new visitor via a QAPI_CLONE() macro that takes care of type-punning
the underlying function pointer, rather than generating lots of
unused functions for types that won't be cloned. And yes, we're
relying on the compiler treating all pointers equally, even though
a strict C program cannot portably do so - but we're not the first
one in the qemu code base to expect it to work (hello, glib!).
The choice of adding a fourth visitor type deserves some explanation.
On the surface, the clone visitor is mostly an input visitor (it
takes arbitrary input - in this case, another QAPI object - and
creates a new QAPI object during the course of the visit). But
ever since commit da72ab0 consolidated enum visits based on the
visitor type, using VISITOR_INPUT would cause us to run
visit_type_str(), even though for cloning there is nothing to do
(we just copy the enum value across, without regards to its mapping
to strings). Also, since our input happens to be a QAPI object,
we can also satisfy the internal checks for VISITOR_OUTPUT. So in
the end, I settled with a new VISITOR_CLONE, and chose its value
such that many internal checks can use 'v->type & mask', sticking
to 'v->type == value' where the difference matters.
Note that we can only clone objects (including alternates) and lists,
not built-ins or enums. The visitor core hides integer width from
the actual visitor (since commit 04e070d), and as long as that's the
case, we can't clone top-level integers. Then again, those can
always be cloned by direct copy, since they are not objects with
deep pointers, so it's no real loss. And restricting cloning to
just objects and lists is cleaner than restricting it to non-integers.
As such, I documented that the clone visitor is for direct use only
by code internal to QAPI, and should not be used on incomplete objects
(other than a hack to work around the fact that we allow NULL in place
of "" in visit_type_str() in other output visitors). Note that as
written, the clone visitor will never fail on a complete object.
Scalars (including enums) not at the root of the clone copy just fine
with no additional effort while visiting the scalar, by virtue of a
g_memdup() each time we push another struct onto the stack. Cloning
a string requires deduplication of a pointer, which means it can also
provide the guarantee of an input visitor of never producing NULL
even when still accepting NULL in place of "" the way the QMP output
visitor does.
Cloning an 'any' type could be possible by incrementing the QObject
refcnt, but it's not obvious whether that is better than implementing
a QObject deep clone. So for now, we document it as unsupported,
and intentionally omit the .type_any() callback to let a developer
know their usage needs implementation.
Add testsuite coverage for several different clone situations, to
ensure that the code is working. I also tested that valgrind was
happy with the test.
Backports commit a15fcc3cf69ee3d408f60d6cc316488d2b0249b4 from qemu
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
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
g_list_insert_sorted_merged() is rather large to be an inline
function; move it to its own file. range_merge() and
ranges_can_merge() can likewise move, as they are only used
internally. Also, it becomes obvious that the condition within
range_merge() is already satisfied by its caller, and that the
return value is not used.
The diffstat is misleading, because of the copyright boilerplate.
Backports commit fec0fc0a13ac7f1a1130433a6740cd850c3db34a from qemu
This will be used by upcoming changes for hashing the tb hash.
Add this into a separate file to include the copyright notice from
xxhash.
Backports commit dc8b295d05ec35a8c032f9abca421772347ba5d4 from qemu
TCG backends do not need most of exec-all.h; extract what they actually
need to a separate file or move it directly to tcg.h. The next patch
will stop including exec-all.h from everywhere.
Backports commit 00f6da6a1a5d1ce085334eccbb50ec899ceed513 from qemu
As described in AArch32.CheckS2Permission an instruction fetch fails if
XN bit is set or there is no read permission for the address.
Backports commit dfda68377e20943f474505e75238cb96bc6874bf from qemu
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
Dan Berrange reported a case where he needs to work with a
QCryptoBlockOptions union type using the OptsVisitor, but only
visit one of the branches of that type (the discriminator is not
visited directly, but learned externally). When things were
boxed, it was easy: just visit the variant directly, which took
care of both allocating the variant and visiting its members, then
store that pointer in the union type. But now that things are
unboxed, we need a way to visit the members without allocation,
done by exposing visit_type_FOO_members() to the user.
Before the patch, we had quite a bit of code associated with
object_members_seen to make sure that a declaration of the helper
was in scope before any use of the function. But now that the
helper is public and declared in the header, the .c file no
longer needs to worry about topological sorting (the helper is
always in scope), which leads to some nice cleanups.
Backports commit 4d91e9115cc6700113e772b19d1f39bbcf345977 from qemu
C types and JSON objects don't have fields, but members. We
shouldn't gratuitously invent terminology. This patch is a
strict renaming of static genarated functions, plus the naming
of the dummy filler member for empty structs, before the next
patch exposes some of that naming to the rest of the code base.
Backports commit c81200b01422783cd29796ef4ccc275d05f9ce67 from qemu
We were passing 'Foo **obj' to the internal helper function, but
all uses within the helper were via reads of '*obj'. Refactor
things to pass one less level of indirection, by having the
callers dereference before calling.
For an example of the generated code change:
|-static void visit_type_BalloonInfo_fields(Visitor *v, BalloonInfo **obj, Error **errp)
|+static void visit_type_BalloonInfo_fields(Visitor *v, BalloonInfo *obj, Error **errp)
| {
| Error *err = NULL;
|
|- visit_type_int(v, "actual", &(*obj)->actual, &err);
|+ visit_type_int(v, "actual", &obj->actual, &err);
| error_propagate(errp, err);
| }
|
|@@ -261,7 +261,7 @@ void visit_type_BalloonInfo(Visitor *v,
| if (!*obj) {
| goto out_obj;
| }
|- visit_type_BalloonInfo_fields(v, obj, &err);
|+ visit_type_BalloonInfo_fields(v, *obj, &err);
| out_obj:
The refactoring will also make it easier to reuse the helpers in
a future patch when implicit structs are stored directly in the
parent struct rather than boxed through a pointer.
Backports commit 655519030b5d20967ae3afa1fe91ef5ad4406065 from qemu
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
Similar to the previous patch, it's nice to have all functions
in the tree that involve a visitor and a name for conversion to
or from QAPI to consistently stick the 'name' parameter next
to the Visitor parameter.
Done by manually changing include/qom/object.h and qom/object.c,
then running this Coccinelle script and touching up the fallout
(Coccinelle insisted on adding some trailing whitespace).
@ rule1 @
identifier fn;
typedef Object, Visitor, Error;
identifier obj, v, opaque, name, errp;
@@
void fn
- (Object *obj, Visitor *v, void *opaque, const char *name,
+ (Object *obj, Visitor *v, const char *name, void *opaque,
Error **errp) { ... }
@@
identifier rule1.fn;
expression obj, v, opaque, name, errp;
@@
fn(obj, v,
- opaque, name,
+ name, opaque,
errp)
Backports commit d7bce9999df85c56c8cb1fcffd944d51bff8ff48 from qemu
C compilers are allowed to represent enums as a smaller type
than int, if all enum values fit in the smaller type. There
are even compiler flags that force the use of this smaller
representation, although using them changes the ABI of a
binary. Therefore, our generated code for visit_type_ENUM()
(for all qapi enums) was wrong for casting Enum* to int* when
calling visit_type_enum().
It appears that no one has been using compiler ABI switches
for qemu, because if they had, we are potentially dereferencing
beyond bounds or even risking a SIGBUS on platforms where
unaligned pointer dereferencing is fatal. But it is still
better to avoid the practice entirely, and just use the correct
types.
This matches the fix for alternate qapi types, done earlier in
commit 0426d53 "qapi: Simplify visiting of alternate types",
with generated code changing as:
| void visit_type_QType(Visitor *v, QType *obj, const char *name, Error **errp)
| {
|- visit_type_enum(v, (int *)obj, QType_lookup, "QType", name, errp);
|+ int value = *obj;
|+ visit_type_enum(v, &value, QType_lookup, "QType", name, errp);
|+ *obj = value;
| }
Backports commit 395a233f7c089f23e3c0d43ce34c709dc5acd7de from qemu
The generated code can call visit_end_union() without having called
visit_start_union(). Example:
if (!*obj) {
goto out_obj;
}
visit_type_CpuInfoBase_fields(v, (CpuInfoBase **)obj, &err);
if (err) {
goto out_obj; // if we go from here...
}
if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) {
goto out_obj;
}
switch ((*obj)->arch) {
[...]
}
out_obj:
// ... then *obj is true, and ...
error_propagate(errp, err);
err = NULL;
if (*obj) {
// we end up here
visit_end_union(v, !!(*obj)->u.data, &err);
}
error_propagate(errp, err);
Harmless only because no visitor implements end_union(). Clean it up
anyway, by deleting the function as useless.
Messed up since we have visit_end_union (commit cee2ded).
Backports commit 7c91aabd8964cfdf637f302c579c95401f21ce92 from qemu
For less code, reflect the determined boolean value of an optional
visit back to the caller instead of making the caller read the
boolean after the fact.
The resulting generated code has the following diff:
|- visit_optional(v, &has_fdset_id, "fdset-id");
|- if (has_fdset_id) {
|+ if (visit_optional(v, &has_fdset_id, "fdset-id")) {
| visit_type_int(v, &fdset_id, "fdset-id", &err);
| if (err) {
| goto out;
| }
| }
Backports commit 29637a6ee913df8fcdf371426ee48956b945b618 from qemu
None of the visitor callbacks would set an error when testing
if an optional field was present; make this part of the interface
contract by eliminating the errp argument.
The resulting generated code has a nice diff:
|- visit_optional(v, &has_fdset_id, "fdset-id", &err);
|- if (err) {
|- goto out;
|- }
|+ visit_optional(v, &has_fdset_id, "fdset-id");
| if (has_fdset_id) {
| visit_type_int(v, &fdset_id, "fdset-id", &err);
| if (err) {
| goto out;
| }
| }
Backports commit 5cdc8831a795fb8452d7e34f644202fd724e122a from qemu
The QMP input visitor allows integral values to be assigned by
promotion to a QTYPE_QFLOAT. However, when parsing an alternate,
we did not take this into account, such that an alternate that
accepts 'number' and some other type, but not 'int', would reject
integral values.
With this patch, we now have the following desirable table:
alternate has case selected for
'int' 'number' QTYPE_QINT QTYPE_QFLOAT
no no error error
no yes 'number' 'number'
yes no 'int' error
yes yes 'int' 'number'
While it is unlikely that we will ever use 'number' in an
alternate other than in the testsuite, it never hurts to be
more precise in what we allow.
Backports commit d00341af384665d259af475b14c96bb8414df415 from qemu
Previously, working with alternates required two lookup arrays
and some indirection: for type Foo, we created Foo_qtypes[]
which maps each qtype to a value of the generated FooKind enum,
then look up that value in FooKind_lookup[] like we do for other
union types.
This has a couple of subtle bugs. First, the generator was
creating a call with a parameter '(int *) &(*obj)->type' where
type is an enum type; this is unsafe if the compiler chooses
to store the enum type in a different size than int, where
assigning through the wrong size pointer can corrupt data or
cause a SIGBUS.
Related bug, not not fixed in this patch: qapi-visit.py's
gen_visit_enum() generates a cast of its enum * argument to
int *. Marked FIXME.
Second, since the values of the FooKind enum start at zero, all
entries of the Foo_qtypes[] array that were not explicitly
initialized will map to the same branch of the union as the
first member of the alternate, rather than triggering a desired
failure in visit_get_next_type(). Fortunately, the bug seldom
bites; the very next thing the input visitor does is try to
parse the incoming JSON with the wrong parser, which normally
fails; the output visitor is not used with a C struct in that
state, and the dealloc visitor has nothing to clean up (so
there is no leak).
However, the second bug IS observable in one case: parsing an
integer causes unusual behavior in an alternate that contains
at least a 'number' member but no 'int' member, because the
'number' parser accepts QTYPE_QINT in addition to the expected
QTYPE_QFLOAT (that is, since 'int' is not a member, the type
QTYPE_QINT accidentally maps to FooKind 0; if this enum value
is the 'number' branch the integer parses successfully, but if
the 'number' branch is not first, some other branch tries to
parse the integer and rejects it). A later patch will worry
about fixing alternates to always parse all inputs that a
non-alternate 'number' would accept, for now this is still
marked FIXME in the updated test-qmp-input-visitor.c, to
merely point out that new undesired behavior of 'ans' matches
the existing undesired behavior of 'asn'.
This patch fixes the default-initialization bug by deleting the
indirection, and modifying get_next_type() to directly assign a
QTypeCode parameter. This in turn fixes the type-casting bug,
as we are no longer casting a pointer to enum to a questionable
size. There is no longer a need to generate an implicit FooKind
enum associated with the alternate type (since the QMP wire
format never uses the stringized counterparts of the C union
member names). Since the updated visit_get_next_type() does not
know which qtypes are expected, the generated visitor is
modified to generate an error statement if an unexpected type is
encountered.
Callers now have to know the QTYPE_* mapping when looking at the
discriminator; but so far, only the testsuite was even using the
C struct of an alternate types. I considered the possibility of
keeping the internal enum FooKind, but initialized differently
than most generated arrays, as in:
typedef enum FooKind {
FOO_KIND_A = QTYPE_QDICT,
FOO_KIND_B = QTYPE_QINT,
} FooKind;
to create nicer aliases for knowing when to use foo->a or foo->b
when inspecting foo->type; but it turned out to add too much
complexity, especially without a client.
There is a user-visible side effect to this change, but I
consider it to be an improvement. Previously,
the invalid QMP command:
{"execute":"blockdev-add", "arguments":{"options":
{"driver":"raw", "id":"a", "file":true}}}
failed with:
{"error": {"class": "GenericError",
"desc": "Invalid parameter type for 'file', expected: QDict"}}
(visit_get_next_type() succeeded, and the error comes from the
visit_type_BlockdevOptions() expecting {}; there is no mention of
the fact that a string would also work). Now it fails with:
{"error": {"class": "GenericError",
"desc": "Invalid parameter type for 'file', expected: BlockdevRef"}}
(the error when the next type doesn't match any expected types for
the overall alternate).
Backports commit 0426d53c6530606bf7641b83f2b755fe61c280ee from qemu
