qapi: Prefer explicit relative imports

All of the QAPI include statements are changed to be package-aware, as
explicit relative imports.

A quirk of Python packages is that the name of the package e

qapi: Prefer explicit relative imports

All of the QAPI include statements are changed to be package-aware, as
explicit relative imports.

A quirk of Python packages is that the name of the package exists only
*outside* of the package. This means that to a module inside of the qapi
folder, there is inherently no such thing as the "qapi" package. The
reason these imports work is because the "qapi" package exists in the
context of the caller -- the execution shim, where sys.path includes a
directory that has a 'qapi' folder in it.

When we write "from qapi import sibling", we are NOT referencing the folder
'qapi', but rather "any package named qapi in sys.path". If you should
so happen to have a 'qapi' package in your path, it will use *that*
package.

When we write "from .sibling import foo", we always reference explicitly
our sibling module; guaranteeing consistency in *where* we are importing
these modules from.

This can be useful when working with virtual environments and packages
in development mode. In development mode, a package is installed as a
series of symlinks that forwards to your same source files. The problem
arises because code quality checkers will follow "import qapi.x" to the
"installed" version instead of the sibling file and -- even though they
are the same file -- they have different module paths, and this causes
cyclic import problems, false positive type mismatch errors, and more.

It can also be useful when dealing with hierarchical packages, e.g. if
we allow qemu.core.qmp, qemu.qapi.parser, etc.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20201009161558.107041-6-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: Fix visit_type_STRUCT() not to fail for null object

To make deallocating partially constructed objects work, the
visit_type_STRUCT() need to succeed without doing anything when passed
a null o

qapi: Fix visit_type_STRUCT() not to fail for null object

To make deallocating partially constructed objects work, the
visit_type_STRUCT() need to succeed without doing anything when passed
a null object.

Commit cdd2b228b9 "qapi: Smooth visitor error checking in generated
code" broke that. To reproduce, run tests/test-qobject-input-visitor
with AddressSanitizer:

==4353==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 16 byte(s) in 1 object(s) allocated from:
#0 0x7f192d0c5d28 in __interceptor_calloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xded28)
#1 0x7f192cd21b10 in g_malloc0 (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x51b10)
#2 0x556725f6bbee in visit_next_list qapi/qapi-visit-core.c:86
#3 0x556725f49e15 in visit_type_UserDefOneList tests/test-qapi-visit.c:474
#4 0x556725f4489b in test_visitor_in_fail_struct_in_list tests/test-qobject-input-visitor.c:1086
#5 0x7f192cd42f29 (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72f29)

SUMMARY: AddressSanitizer: 16 byte(s) leaked in 1 allocation(s).

Test case /visitor/input/fail/struct-in-list feeds a list with a bad
element to the QObject input visitor. Visiting that element duly
fails, and aborts the visit with the list only partially constructed:
the faulty object is null. Cleaning up the partially constructed list
visits that null object, fails, and aborts the visit before the list
node gets freed.

Fix the the generated visit_type_STRUCT() to succeed for null objects.

Fixes: cdd2b228b973d2a29edf7696ef6e8b08ec329019
Reported-by: Li Qiang <liq3ea@163.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200716150617.4027356-1-armbru@redhat.com>
Tested-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>

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qapi: Smooth visitor error checking in generated code

Use visitor functions' return values to check for failure. Eliminate
error_propagate() that are now unnecessary. Delete @err that are now
unus

qapi: Smooth visitor error checking in generated code

Use visitor functions' return values to check for failure. Eliminate
error_propagate() that are now unnecessary. Delete @err that are now
unused.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-41-armbru@redhat.com>

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qapi: Make visitor functions taking Error ** return bool, not void

See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Revi

qapi: Make visitor functions taking Error ** return bool, not void

See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-18-armbru@redhat.com>

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qapi: Assert non-input visitors see only valid alternate tags

An alternate type's visit_type_FOO() fails when it runs into an
invalid ->type.

This is appropriate with an input visitor: visit_start_

qapi: Assert non-input visitors see only valid alternate tags

An alternate type's visit_type_FOO() fails when it runs into an
invalid ->type.

This is appropriate with an input visitor: visit_start_alternate()
sets ->type according to the input, and bad input can lead to bad
->type.

It should never happen with an output, clone or dealloc visitor: if it
did, the alternate being output, cloned or deallocated would be messed
up beyond repair. Assert that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-12-armbru@redhat.com>

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qapi: Clean up visitor's recovery from input with invalid type

An alternate type's visit_type_FOO() fails when it runs into an
invalid ->type. If it's an input visit, we then need to free the the
o

qapi: Clean up visitor's recovery from input with invalid type

An alternate type's visit_type_FOO() fails when it runs into an
invalid ->type. If it's an input visit, we then need to free the the
object we got from visit_start_alternate(). We do that with
qapi_free_FOO(), which uses the dealloc visitor.

Trouble is that object is in a bad state: its ->type is invalid. So
the dealloc visitor will run into the same error again, and the error
recovery skips deallocating the alternate's (invalid) alternative.
Works, because qapi_free_FOO() ignores the error.

Avoid it instead: free the messed up object with by g_free().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200424084338.26803-11-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

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qapi: Assert incomplete object occurs only in dealloc visitor

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-7-arm

qapi: Assert incomplete object occurs only in dealloc visitor

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200424084338.26803-7-armbru@redhat.com>

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qapi: Consistently put @features parameter right after @ifcond

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Bla

qapi: Consistently put @features parameter right after @ifcond

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200317115459.31821-14-armbru@redhat.com>

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qapi: Add feature flags to remaining definitions

In v4.1.0, we added feature flags just to struct types (commit
6a8c0b5102^..f3ed93d545), to satisfy an immediate need (commit
c9d4070991 "file-posix:

qapi: Add feature flags to remaining definitions

In v4.1.0, we added feature flags just to struct types (commit
6a8c0b5102^..f3ed93d545), to satisfy an immediate need (commit
c9d4070991 "file-posix: Add dynamic-auto-read-only QAPI feature"). In
v4.2.0, we added them to commands (commit 23394b4c39 "qapi: Add
feature flags to commands") to satisfy another immediate need (commit
d76744e65e "qapi: Allow introspecting fix for savevm's cooperation
with blockdev").

Add them to the remaining definitions: enumeration types, union types,
alternate types, and events.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200317115459.31821-13-armbru@redhat.com>

show more ...

qapi: Use super() now we have Python 3

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200304155932.20452-4-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>

qapi: Simplify QAPISchemaModularCVisitor

Since the previous commit, QAPISchemaVisitor.visit_module() is called
just once. Simplify QAPISchemaModularCVisitor accordingly.

Signed-off-by: Markus Armb

qapi: Simplify QAPISchemaModularCVisitor

Since the previous commit, QAPISchemaVisitor.visit_module() is called
just once. Simplify QAPISchemaModularCVisitor accordingly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191120182551.23795-7-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

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qapi: Split up scripts/qapi/common.py

The QAPI code generator clocks in at some 3100 SLOC in 8 source files.
Almost 60% of the code is in qapi/common.py. Split it into more
focused modules:

* Move

qapi: Split up scripts/qapi/common.py

The QAPI code generator clocks in at some 3100 SLOC in 8 source files.
Almost 60% of the code is in qapi/common.py. Split it into more
focused modules:

* Move QAPISchemaPragma and QAPISourceInfo to qapi/source.py.

* Move QAPIError and its sub-classes to qapi/error.py.

* Move QAPISchemaParser and QAPIDoc to parser.py. Use the opportunity
to put QAPISchemaParser first.

* Move check_expr() & friends to qapi/expr.py. Use the opportunity to
put the code into a more sensible order.

* Move QAPISchema & friends to qapi/schema.py

* Move QAPIGen and its sub-classes, ifcontext,
QAPISchemaModularCVisitor, and QAPISchemaModularCVisitor to qapi/gen.py

* Delete camel_case(), it's unused since commit e98859a9b9 "qapi:
Clean up after recent conversions to QAPISchemaVisitor"

A number of helper functions remain in qapi/common.py. I considered
moving the code generator helpers to qapi/gen.py, but decided not to.
Perhaps we should rewrite them as methods of QAPIGen some day.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20191018074345.24034-7-armbru@redhat.com>
[Add "# -*- coding: utf-8 -*-" lines]

show more ...

qapi: Add feature flags to struct types

Sometimes, the behaviour of QEMU changes without a change in the QMP
syntax (usually by allowing values or operations that previously
resulted in an error). Q

qapi: Add feature flags to struct types

Sometimes, the behaviour of QEMU changes without a change in the QMP
syntax (usually by allowing values or operations that previously
resulted in an error). QMP clients may still need to know whether
they can rely on the changed behavior.

Let's add feature flags to the QAPI schema language, so that we can make
such changes visible with schema introspection.

An example for a schema definition using feature flags looks like this:

{ 'struct': 'TestType',
'data': { 'number': 'int' },
'features': [ 'allow-negative-numbers' ] }

Introspection information then looks like this:

{ "name": "TestType", "meta-type": "object",
"members": [
{ "name": "number", "type": "int" } ],
"features": [ "allow-negative-numbers" ] }

This patch implements feature flags only for struct types. We'll
implement them more widely as needed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190606153803.5278-2-armbru@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

Include qemu-common.h exactly where needed

No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Me

Include qemu-common.h exactly where needed

No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]

show more ...

qapi: Prepare for system modules other than 'builtin'

The next commit wants to generate qapi-emit-events.{c.h}. To enable
that, extend QAPISchemaModularCVisitor to support additional "system
module

qapi: Prepare for system modules other than 'builtin'

The next commit wants to generate qapi-emit-events.{c.h}. To enable
that, extend QAPISchemaModularCVisitor to support additional "system
modules", i.e. modules that don't correspond to a (user-defined) QAPI
schema module.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190214152251.2073-5-armbru@redhat.com>

show more ...

qapi: Clean up modular built-in code generation a bit

We neglect to call .visit_module() for the special module we use for
built-ins. Harmless, but clean it up anyway. The
tests/qapi-schema/*.out

qapi: Clean up modular built-in code generation a bit

We neglect to call .visit_module() for the special module we use for
built-ins. Harmless, but clean it up anyway. The
tests/qapi-schema/*.out now show the built-in module as 'module None'.

Subclasses of QAPISchemaModularCVisitor need to ._add_module() this
special module to enable code generation for built-ins. When this
hasn't been done, QAPISchemaModularCVisitor.visit_module() does
nothing for the special module. That looks like built-ins could
accidentally be generated into the wrong module when a subclass
neglects to call ._add_module(). Can't happen, because built-ins are
all visited before any other module. But that's non-obvious. Switch
off code generation explicitly.

Rename QAPISchemaModularCVisitor._begin_module() to
._begin_user_module().

New QAPISchemaModularCVisitor._is_builtin_module(), for clarity.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190214152251.2073-4-armbru@redhat.com>

show more ...

qapi: Add #if conditions to generated code members

Wrap generated enum and struct members and their supporting code with
#if/#endif, using the .ifcond members added in the previous patches.

We do e

qapi: Add #if conditions to generated code members

Wrap generated enum and struct members and their supporting code with
#if/#endif, using the .ifcond members added in the previous patches.

We do enum and struct in a single patch because union tag enum and the
associated variants tie them together, and dealing with that to split
the patch doesn't seem worthwhile.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20181213123724.4866-18-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi: change enum visitor and gen_enum* to take QAPISchemaMember

This will allow to add and access more properties associated with enum
values/members, like the associated 'if' condition. We may wan

qapi: change enum visitor and gen_enum* to take QAPISchemaMember

This will allow to add and access more properties associated with enum
values/members, like the associated 'if' condition. We may want to
have a specialized type QAPISchemaEnumMember, for now this will do.

Modify gen_enum() and gen_enum_lookup() for the same reason.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20181213123724.4866-3-marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

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qapi: Fix some pycodestyle-3 complaints

Fix the following issues:

common.py:873:13: E129 visually indented line with same indent as next logical line
common.py:1766:5: E741 ambiguous variab

qapi: Fix some pycodestyle-3 complaints

Fix the following issues:

common.py:873:13: E129 visually indented line with same indent as next logical line
common.py:1766:5: E741 ambiguous variable name 'l'
common.py:1784:1: E305 expected 2 blank lines after class or function definition, found 1
common.py:1833:1: E305 expected 2 blank lines after class or function definition, found 1
common.py:1843:1: E305 expected 2 blank lines after class or function definition, found 1
visit.py:181:18: E127 continuation line over-indented for visual indent

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20180621083551.775-1-armbru@redhat.com>
[Fixup squashed in:]
Message-ID: <871sd0nzw9.fsf@dusky.pond.sub.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

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qapi-types: add #if conditions to types & visitors

Types & visitors are coupled and must be handled together to avoid
temporary build regression.

Wrap generated types/visitor code with #if/#endif u

qapi-types: add #if conditions to types & visitors

Types & visitors are coupled and must be handled together to avoid
temporary build regression.

Wrap generated types/visitor code with #if/#endif using the context
helpers. Derived from a patch by Marc-André.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180703155648.11933-12-marcandre.lureau@redhat.com>

show more ...

qapi: add 'ifcond' to visitor methods

Modify the test visitor to check correct passing of values.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armb

qapi: add 'ifcond' to visitor methods

Modify the test visitor to check correct passing of values.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180703155648.11933-5-marcandre.lureau@redhat.com>
[Accidental change to roms/seabios dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

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qapi: allow empty branches in flat unions

It often happens that just a few discriminator values imply extra data in
a flat union. Existing checks did not make possible to leave other values
uncovere

qapi: allow empty branches in flat unions

It often happens that just a few discriminator values imply extra data in
a flat union. Existing checks did not make possible to leave other values
uncovered. Such cases had to be worked around by either stating a dummy
(empty) type or introducing another (subset) discriminator enumeration.

Both options create redundant entities in qapi files for little profit.

With this patch it is not necessary anymore to add designated union
fields for every possible value of a discriminator enumeration.

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Message-Id: <1529311206-76847-2-git-send-email-anton.nefedov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

qapi/visit: remove useless prefix argument

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180321115211.17937-2-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbrus

qapi/visit: remove useless prefix argument

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20180321115211.17937-2-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

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qapi: Move qapi-schema.json to qapi/, rename generated files

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 module

qapi: Move qapi-schema.json to qapi/, rename generated files

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.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180211093607.27351-28-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
[eblake: Fix trailing dot in tpm.c, undo temporary hack for OSX toolchain]
Signed-off-by: Eric Blake <eblake@redhat.com>

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Include less of the generated modular QAPI headers

In my "build everything" tree, a change to the types in
qapi-schema.json triggers a recompile of about 4800 out of 5100
objects.

The previous comm

Include less of the generated modular QAPI headers

In my "build everything" tree, a change to the types in
qapi-schema.json triggers a recompile of about 4800 out of 5100
objects.

The previous commit split up qmp-commands.h, qmp-event.h, qmp-visit.h,
qapi-types.h. Each of these headers still includes all its shards.
Reduce compile time by including just the shards we actually need.

To illustrate the benefits: adding a type to qapi/migration.json now
recompiles some 2300 instead of 4800 objects. The next commit will
improve it further.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180211093607.27351-24-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[eblake: rebase to master]
Signed-off-by: Eric Blake <eblake@redhat.com>

show more ...