Commit graph

64 commits

Author SHA1 Message Date
Markus Armbruster 64e9fceab9
qapi: Replace dirty is_c_ptr() by method c_null()
is_c_ptr() looks whether the end of the C text for the type looks like
a pointer. Works, but is fragile.

We now have a better tool: use QAPISchemaType method c_null(). The
initializers for non-pointers become prettier: 0, false or the
enumeration constant with the value 0 instead of {0}.

Backports commit 5710153e7310995b5d4127af267e36d8529b3b30 from qemu
2018-02-19 17:17:40 -05:00
Markus Armbruster 533bf08ff1
qapi-event: Eliminate global variable event_enum_value
Backports commit 7b24626cd019ed5084c8e3370999176a1ebd44be from qemu
2018-02-19 17:13:37 -05:00
Markus Armbruster 782a549898
qapi: De-duplicate enum code generation
Duplicated in commit 21cd70d. Yes, we can't import qapi-types, but
that's no excuse. Move the helpers from qapi-types.py to qapi.py, and
replace the duplicates in qapi-event.py.

The generated event enumeration type's lookup table becomes
const-correct (see commit 2e4450f), and uses explicit indexes instead
of relying on order (see commit 912ae9c).

Backports commit efd2eaa6c2992c214a13f102b6ddd4dca4697fb3 from qemu
2018-02-19 17:11:05 -05:00
Markus Armbruster 03634275b1
qapi-types: Convert to QAPISchemaVisitor, fixing flat unions
Fixes flat unions to get the base's base members. Test case is from
commit 2fc0043, in qapi-schema-test.json:

{ 'union': 'UserDefFlatUnion',
'base': 'UserDefUnionBase',
'discriminator': 'enum1',
'data': { 'value1' : 'UserDefA',
'value2' : 'UserDefB',
'value3' : 'UserDefB' } }

{ 'struct': 'UserDefUnionBase',
'base': 'UserDefZero',
'data': { 'string': 'str', 'enum1': 'EnumOne' } }

{ 'struct': 'UserDefZero',
'data': { 'integer': 'int' } }

Patch's effect on UserDefFlatUnion:

struct UserDefFlatUnion {
/* Members inherited from UserDefUnionBase: */
+ int64_t integer;
char *string;
EnumOne enum1;
/* Own members: */
union { /* union tag is @enum1 */
void *data;
UserDefA *value1;
UserDefB *value2;
UserDefB *value3;
};
};

Flat union visitors remain broken. They'll be fixed next.

Code is generated in a different order now, but that doesn't matter.

The two guards QAPI_TYPES_BUILTIN_STRUCT_DECL and
QAPI_TYPES_BUILTIN_CLEANUP_DECL are replaced by just
QAPI_TYPES_BUILTIN.

Two ugly special cases for simple unions now stand out like sore
thumbs:

1. The type tag is named 'type' everywhere, except in generated C,
where it's 'kind'.

2. QAPISchema lowers simple unions to semantically equivalent flat
unions. However, the C generated for a simple unions differs from
the C generated for its equivalent flat union, and we therefore
need special code to preserve that pointless difference for now.

Mark both TODO.

Backports commit 2b162ccbe875e5323fc04c1009addbdea4d35220 from qemu
2018-02-19 16:58:34 -05:00
Lioncash 72f6d68002
qapi: New QAPISchemaVisitor
The visitor will help keeping the code generation code simple and
reasonably separated from QAPISchema details.

Backports commit 3f7dc21bee1e930d5cccf607b8f83831c3bbdb09 from qemu
2018-02-19 16:50:02 -05:00
Markus Armbruster 8ce395e073
qapi: QAPISchema code generation helper methods
New methods c_name(), c_type(), c_null(), json_type(),
alternate_qtype().

Backports commit f51d8c3db11b0f3052b3bb4b8b0c7f0bc76f7136 from qemu
2018-02-19 16:47:35 -05:00
Markus Armbruster a3660e451d
qapi: New QAPISchema intermediate reperesentation
The QAPI code generators work with a syntax tree (nested dictionaries)
plus a few symbol tables (also dictionaries) on the side.

They have clearly outgrown these simple data structures. There's lots
of rummaging around in dictionaries, and information is recomputed on
the fly. For the work I'm going to do, I want more clearly defined
and more convenient interfaces.

Going forward, I also want less coupling between the back-ends and the
syntax tree, to make messing with the syntax easier.

Create a bunch of classes to represent QAPI schemata.

Have the QAPISchema initializer call the parser, then walk the syntax
tree to create the new internal representation, and finally perform
semantic analysis.

Shortcut: the semantic analysis still relies on existing check_exprs()
to do the actual semantic checking. All this code needs to move into
the classes. Mark as TODO.

Simple unions are lowered to flat unions. Flat unions and structs are
represented as a more general object type.

Catching name collisions in generated code would be nice. Mark as
TODO.

We generate array types eagerly, even though most of them aren't used.
Mark as TODO.

Nothing uses the new intermediate representation just yet, thus no
change to generated files.

Backports commit ac88219a6c78302c693fb60fe6cf04358540fbce from qemu
2018-02-19 16:43:30 -05:00
Markus Armbruster 448a2e95ac
qapi: Rename class QAPISchema to QAPISchemaParser
I want to name a new class QAPISchema.

While there, make it a new-style class.

Backports commit a4bcb2080d5c1d08bab512d76fb260296e2cae74 from qemu
2018-02-19 16:41:00 -05:00
Daniel P. Berrange fe90a5c914
qapi: allow override of default enum prefix naming
The camel_to_upper() method applies some heuristics to turn
a mixed case type name into an all-uppercase name. This is
used for example, to generate enum constant name prefixes.

The heuristics don't also generate a satisfactory name
though. eg

{ 'enum': 'QCryptoTLSCredsEndpoint',
'data': ['client', 'server']}

Results in Q_CRYPTOTLS_CREDS_ENDPOINT_CLIENT. This has
an undesirable _ after the initial Q and is missing an
_ between the CRYPTO & TLS strings.

Rather than try to add more and more heuristics to try
to cope with this, simply allow the QAPI schema to
specify the desired enum constant prefix explicitly.

eg

{ 'enum': 'QCryptoTLSCredsEndpoint',
'prefix': 'QCRYPTO_TLS_CREDS_ENDPOINT',
'data': ['client', 'server']}

Now gives the QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT name.

Backports commit 351d36e454cddc67a1675740916636a7ccbf1c4b from qemu
2018-02-19 16:38:48 -05:00
Markus Armbruster d59948f245
qapi: Fix cgen() for Python older than 2.7
A feature new in Python 2.7 crept into commit 77e703b: re.subn()'s
fifth argument.  Avoid that, use re.compile().

Backports commit 2752e5bedb26fa0c7291f810f9f534b688b2f1d2 from qemu
2018-02-19 16:34:17 -05:00
Markus Armbruster 809b439562
qapi: Generators crash when --output-dir isn't given, fix
Backports commit c4f498fe8532cdacc609262b104322911108df54 from qemu
2018-02-19 16:32:50 -05:00
Markus Armbruster 741783073f
qapi: Simplify error reporting for array types
check_type() first checks and peels off the array type, then checks
the element type. For two out of four error messages, it takes pains
to report errors for "array of T" instead of just T. Odd. Let's
examine the errors.

* Unknown element type, e.g.
tests/qapi-schema/args-array-unknown.json:

Member 'array' of 'data' for command 'oops' uses unknown type
'array of NoSuchType'

To make sense of this, you need to know that 'array of NoSuchType'
refers to '[NoSuchType]'. Easy enough. However, simply reporting

Member 'array' of 'data' for command 'oops' uses unknown type
'NoSuchType'

is at least as easy to understand.

* Element type's meta-type is inadmissible, e.g.
tests/qapi-schema/returns-whitelist.json:

'returns' for command 'no-way-this-will-get-whitelisted' cannot
use built-in type 'array of int'

'array of int' is technically not a built-in type, but that's
pedantry. However, simply reporting

'returns' for command 'no-way-this-will-get-whitelisted' cannot
use built-in type 'int'

avoids the issue, and is at least as easy to understand.

* The remaining two errors are unreachable, because the array checking
ensures that value is a string.

Thus, reporting some errors for "array of T" instead of just T works,
but doesn't really improve things. Drop it.

Backports commit eddf817bd823a90df209dfbdc2a0b2ec33b7cb77 from qemu
2018-02-19 16:31:44 -05:00
Markus Armbruster 630b56b4a2
qapi: Fix errors for non-string, non-dictionary members
Backports commit c6b71e5ae73802057d700e2419b80aef1651f213 from qemu
2018-02-19 16:30:50 -05:00
Markus Armbruster 16619a738e
qapi: Drop one of two "simple union must not have base" checks
The first check ensures the second one can't trigger. Drop the first
one, because the second one is in a more logical place, and emits a
nicer error message.

Backports commit 65fbe125451da9421070ab03944c9600a264eefc from qemu
2018-02-19 16:29:58 -05:00
Markus Armbruster c5e8b70b5a
qapi: Command returning anonymous type doesn't work, outlaw
Reproducer: with

{ 'command': 'user_def_cmd4', 'returns': { 'a': 'int' } }

added to qapi-schema-test.json, qapi-commands.py dies when it tries to
generate the command handler function

Traceback (most recent call last):
File "/work/armbru/qemu/scripts/qapi-commands.py", line 359, in <module>
ret = generate_command_decl(cmd['command'], arglist, ret_type) + "\n"
File "/work/armbru/qemu/scripts/qapi-commands.py", line 29, in generate_command_decl
ret_type=c_type(ret_type), name=c_name(name),
File "/work/armbru/qemu/scripts/qapi.py", line 927, in c_type
assert isinstance(value, str) and value != ""
AssertionError

because the return type doesn't exist.

Simply outlaw this usage, and drop or dumb down test cases accordingly.

Backports commit 9b090d42aea9a0abbf39a1d75561a186057b5fe6 from qemu
2018-02-19 16:24:14 -05:00
Markus Armbruster 8d992dfa48
qapi: Fix to reject union command and event arguments
A command's or event's 'data' must be a struct type, given either as a
dictionary, or as struct type name.

Commit dd883c6 tightened the checking there, but not enough: we still
accept 'union'. Fix to reject it.

We may want to support union types there, but we'll have to extend
qapi-commands.py and qapi-events.py for it.

Backports commit 315932b5edb86597adafbd1faa2d29c46499d8c3 from qemu
2018-02-19 16:23:24 -05:00
Markus Armbruster eed32a1c57
qapi: Document flaws in checking of names
We don't actually enforce our "other than downstream extensions [...],
all names should begin with a letter" rule. Add a FIXME.

We should reject names that differ only in '_' vs. '.' vs. '-',
because they're liable to clash in generated C. Add a FIXME.

Backports commit d90675fa4bc256238b3dd3a7fdd5f9029eca00b8 from qemu
2018-02-19 16:22:35 -05:00
Markus Armbruster b190e4887e
qapi: Drop unused and useless parameters and variables
gen_sync_call()'s parameter indent is useless: gen_sync_call() uses it
only as optional argument for push_indent() and pop_indent(), their
default is four, and gen_sync_call()'s only caller passes four. Drop
the parameter.

gen_visitor_input_containers_decl()'s parameter obj is always
"QOBJECT(args)". Use that, and drop the parameter.

Drop unused parameters of gen_marshal_output(),
gen_marshal_input_decl(), generate_visit_struct_body(),
generate_visit_list(), generate_visit_enum(), generate_declaration(),
generate_enum_declaration(), generate_decl_enum().

Drop unused variables in generate_event_enum_lookup(),
generate_enum_lookup(), generate_visit_struct_fields(), check_event().

Backports commit 5aa05d3f72e556752167f7005d6a3dea0f4432c5 from qemu
2018-02-19 16:11:35 -05:00
Markus Armbruster cf9d457200
qapi: Reject -p arguments that break qapi-event.py
qapi-event.py breaks when you ask for a funny prefix like '@'.
Protect it.

Backports commit 1cf47a15f18312436c7fa2d97be5fbe6df0292f5 from qemu
2018-02-19 16:07:40 -05:00
Markus Armbruster 6dcb71a788
qapi: Simplify guardname()
The guards around built-in declarations lose their _H. It never made
much sense anyway.

Backports commit 00dfc3b2c272d98556ec6095d56bdd8b036babf9 from qemu
2018-02-19 16:05:52 -05:00
Markus Armbruster e100831af9
qapi: Clean up cgen() and mcgen()
Commit 05dfb26 added eatspace stripping to mcgen(). Move it to
cgen(), just in case somebody gets tempted to use cgen() directly
instead of via mcgen().

cgen() indents blank lines. No such lines get generated right now,
but fix it anyway.

We use triple-quoted strings for program text, like this:

'''
Program text
any number of lines
'''

Keeps the program text relatively readable, but puts an extra newline
at either end. mcgen() "fixes" that by dropping the first and last
line outright. Drop only the newlines.

This unmasks a bug in qapi-commands.py: four quotes instead of three.
Fix it up.

Output doesn't change

Backports commit 77e703b861d34bb2879f3e845482d5cf0a3a0ad1 from qemu
2018-02-19 16:04:37 -05:00
Markus Armbruster ed3da56d26
qapi: Catch and reject flat union branch of array type
Backports commit f9a1427361fe06ac67480d580412dc4ed6f5d03b from qemu
2018-02-19 15:48:12 -05:00
Markus Armbruster 52e7d76d23
qapi: Better separate the different kinds of helpers
Insert comments to separate sections dealing with parsing, semantic
analysis, code generation, and so forth.

Move helpers to their proper section.

Backports commit 00e4b285a31d19dcd88bd46729c9e09bfc9cc7fd from qemu
2018-02-19 15:47:21 -05:00
Markus Armbruster 0a8ab4fc40
qapi: Move exprs checking from parse_schema() to check_exprs()
To have expression semantic analysis in one place rather than two.

Backports commit 4d076d67c2c74662db092ecf4f99600b18209b2e from qemu
2018-02-19 15:45:24 -05:00
Markus Armbruster 72e6966bba
qapi: Fix to reject stray 't', 'f' and 'n'
Screwed up in commit e53188a.

Backports commit e565d934d21e3544b820cd03b88061e71ab644a0 from qemu
2018-02-19 15:41:38 -05:00
Markus Armbruster de88f40dfd
qapi: Simplify inclusion cycle detection
We maintain a stack of filenames in include_hist for convenient cycle
detection.

As error_path() demonstrates, the same information is readily
available in the expr_info, so just use that, and drop include_hist.

Backports commit a1366087270b312d94ff8c4031395a4218f160d4 from qemu
2018-02-19 15:40:44 -05:00
Markus Armbruster b387a62f73
qapi: Fix file name in error messages for included files
We print the name as it appears in the include expression. Tools
processing error messages want it relative to the working directory.
Make it so.

Backports commit 8608d2525186062099a38971c276752e7a38903a from qemu
2018-02-19 15:39:08 -05:00
Markus Armbruster a48f709cd8
qapi: Eliminate superfluous QAPISchema attribute input_dir
qapi: Improve a couple of confusing variable names

Backports commits 12c707944927b8aa42752198dcf419a0bafe5d33 and
54414047eca5bee7d5ba6e7af5fb251f8635896c from qemu
2018-02-19 15:37:52 -05:00
Markus Armbruster faffdb784a
qapi: Drop pointless flush() before close()
Backports commit 09896d3f48078a93e3d2dbd8ef86436b85ebda7c from qemu
2018-02-19 15:33:00 -05:00
Markus Armbruster 2c9ed3c379
qapi: Factor open_output(), close_output() out of generators
Backports commit 12f8e1b9ff57e99dafbb13f89cd5a99ad5c28527 from qemu
2018-02-19 15:32:28 -05:00
Markus Armbruster d77e0dd040
qapi: Turn generators' mandatory option -i into an argument
Mandatory option is silly, and the error handling is missing: the
programs crash when -i isn't supplied. Make it an argument, and check
it properly.

Backports commit 16d80f61814745bd3f5bb9f47ae3b00edf9e1e45 from qemu
2018-02-19 15:22:27 -05:00
Markus Armbruster dd67bbeb3b
qapi: Fix generators to report command line errors decently
Report to stderr, prefix with the program name. Also reject
extra arguments.

Backports commit b45409683e829770000a4560ed21e704f87df74c from qemu
2018-02-19 15:20:07 -05:00
Markus Armbruster 9415f6e863
qapi: Factor parse_command_line() out of the generators
Backports commit 2114f5a98d0d80774306279e1694de074ca86aa0 from qemu
2018-02-19 15:19:13 -05:00
Eric Blake 2dcd6722fa
qapi: Support downstream alternates
Enhance the testsuite to cover downstream alternates, including
whether the branch name or type is downstream. Update the
generator to mangle alternate names in the appropriate places.

Backports commit d1f07c86c05706facf950b0b0dba370f71fd5ef6 from qemu
2018-02-19 15:10:14 -05:00
Eric Blake 2045cd0ada
qapi: Make c_type() consistently convert qapi names
Continuing the string of cleanups for supporting downstream names
containing '.', this patch focuses on ensuring c_type() can
handle a downstream name. This patch alone does not fix the
places where generator output should be calling this function
but was open-coding things instead, but it gets us a step closer.

In particular, the changes to c_list_type() and type_name() mean
that type_name(FOO) now handles the case when FOO contains '.',
'-', or is a ticklish identifier other than a builtin (builtins
are exempted because ['int'] must remain mapped to 'intList' and
not 'q_intList'). Meanwhile, ['unix'] now maps to 'q_unixList'
rather than 'unixList', to match the fact that 'unix' is ticklish;
however, our naming conventions state that complex types should
start with a capital, so no type name following conventions will
ever have the 'q_' prepended.

Likewise, changes to c_type() mean that c_type(FOO) properly
handles an enum or complex type FOO with '.' or '-' in the
name, or is a ticklish identifier (again, a ticklish identifier
as a type name violates conventions).

Backports commit c6405b54b7b09a876f2f2fba2aa6f8ac87189cb9 from qemu
2018-02-19 14:56:49 -05:00
Eric Blake 7ec0edc6c6
qapi: Tidy c_type() logic
c_type() is designed to be called on both string names and on
array designations, so 'name' is a bit misleading because it
operates on more than strings. Also, no caller ever passes
an empty string. Finally, + notation is a bit nicer to read
than '%s' % value for string concatenation.

Backports commit d557344628e32771f07e5b6a2a818ee3d8e7a65f from qemu
2018-02-19 14:53:56 -05:00
Markus Armbruster 5bc3d84705
qapi: Move camel_to_upper(), c_enum_const() to closely related code
Backports commit 849bc5382e42b3b9590c6a50ba30c2fd2450308c from qemu
2018-02-19 14:51:03 -05:00
Markus Armbruster e339979717
qapi: Simplify c_enum_const()
Backports commit 02e20c7e593363c564aae96e3c5bdc58630ce584 from qemu
2018-02-19 14:50:04 -05:00
Markus Armbruster b0adaeb172
qapi: Rename generate_enum_full_value() to c_enum_const()
Backports commit 7c81c61f9c2274f66ba947eafd9618d60da838a6 from qemu
2018-02-19 14:49:20 -05:00
Markus Armbruster 8c7bbc2dce
qapi: Rename _generate_enum_string() to camel_to_upper()
Backports commit fa6068a1e8ef3c878ac9ee2399bb01eeaf61c366 from qemu
2018-02-19 14:46:49 -05:00
Eric Blake f114c7b027
qapi: Rename identical c_fun()/c_var() into c_name()
Now that the two functions are identical, we only need one of them,
and we might as well give it a more descriptive name. Basically,
the function serves as the translation from a QAPI name into a
(portion of a) C identifier, without regards to whether it is a
variable or function name.

Backports commit 18df515ebbefa9f13474b128b8050d5fa346ea1e from qemu
2018-02-19 14:45:04 -05:00
Markus Armbruster baab1986a3
qapi: Fix C identifiers generated for names containing '.'
c_fun() maps '.' to '_', c_var() doesn't. Nothing prevents '.' in
QAPI names that get passed to c_var().

Which QAPI names get passed to c_fun(), to c_var(), or to both is not
obvious. Names of command parameters and struct type members get
passed to c_var().

c_var() strips a leading '*', but this cannot happen. c_fun()
doesn't.

Fix c_var() to work exactly like c_fun().

Perhaps they should be replaced by a single mapping function.

Backports commit 47299262de424af0cb69965d082e5e70b2314183 from qemu
2018-02-19 14:41:06 -05:00
Eric Blake 7a82e7ff73
qapi: Check for member name conflicts with a base class
Our type inheritance for both 'struct' and for flat 'union' merges
key/value pairs from the base class with those from the type in
question. Although the C code currently boxes things so that there
is a distinction between which member is referred to, the QMP wire
format does not allow passing a key more than once in a single
object. Besides, if we ever change the generated C code to not be
quite so boxy, we'd want to avoid duplicate member names there,
too.

Fix a testsuite entry added in an earlier patch, as well as adding
a couple more tests to ensure we have appropriate coverage. Ensure
that collisions are detected, regardless of whether there is a
difference in opinion on whether the member name is optional.

Backports commit ff55d72eaf9628e7d58e7b067b361cdbf789c9f4 from qemu
2018-02-19 14:38:46 -05:00
Eric Blake 90dfdc5278
qapi: Support (subset of) \u escapes in strings
The handling of \ inside QAPI strings was less than ideal, and
really only worked JSON's \/, \\, \", and our extension of \'
(an obvious extension, when you realize we use '' instead of ""
for strings). For other things, like '\n', it resulted in a
literal 'n' instead of a newline.

Of course, at the moment, we really have no use for escaped
characters, as QAPI has to map to C identifiers, and we currently
support ASCII only for that. But down the road, we may add
support for default values for string parameters to a command
or struct; if that happens, it would be nice to correctly support
all JSON escape sequences, such as \n or \uXXXX. This gets us
closer, by supporting Unicode escapes in the ASCII range.

Since JSON does not require \OCTAL or \xXX escapes, and our QMP
implementation does not understand them either, I intentionally
reject it here, but it would be an easy addition if we desired it.
Likewise, intentionally refusing the NUL byte means we don't have
to worry about C strings being shorter than the qapi input.

Backports commit a7f5966b297330f6492020019544ae87c45d699b from qemu
2018-02-19 14:36:54 -05:00
Eric Blake 8d2f349447
qapi: Drop support for inline nested types
A future patch will be using a 'name':{dictionary} entry in the
QAPI schema to specify a default value for an optional argument
(see previous commit messages for more details why); but existing
use of inline nested structs conflicts with that goal. Now that
all commands have been changed to avoid inline nested structs,
nuke support for them, and turn it into a hard error. Update the
testsuite to reflect tighter parsing rules.

Backports commit 6b5abc7df7ef9aadb3ff0eba6ccf4f1f0181e2e1 from qemu
2018-02-19 14:30:36 -05:00
Eric Blake 2d6d612c61
qapi: Forbid 'type' in schema
Referring to "type" as both a meta-type (built-in, enum, union,
alternate, or struct) and a specific type (the name that the
schema uses for declaring structs) is confusing. Finish up the
conversion to using "struct" in qapi schema by removing the hack
in the generator that allowed 'type'.

Backports commit 3e391d355644b2bff7c9f187759aadb46c6e051f from qemu
2018-02-19 14:23:21 -05:00
Eric Blake b18ac34baa
qapi: Require ASCII in schema
Python 2 and Python 3 have a wild history of whether strings
default to ascii or unicode, where Python 3 requires checking
isinstance(foo, basestr) to cover all strings, but where that
code is not portable to Python 2. It's simpler to just state
that we don't care about Unicode strings, and to just always
use the simpler isinstance(foo, str) everywhere.

I'm no python expert, so I'm basing it on this conversation:
https://lists.gnu.org/archive/html/qemu-devel/2014-09/msg05278.html

Backports commit fe2a9303c9e511462f662a415c2e9d2defe9b7ca from qemu
2018-02-19 14:18:52 -05:00
Eric Blake 0fc76ffc1f
qapi: Prefer 'struct' over 'type' in generator
Referring to "type" as both a meta-type (built-in, enum, union,
alternate, or struct) and a specific type (the name that the
schema uses for declaring structs) is confusing. The confusion
is only made worse by the fact that the generator mostly already
refers to struct even when dealing with expr['type']. This
commit changes the generator to consistently refer to it as
struct everywhere, plus a single back-compat tweak that allows
accepting the existing .json files as-is, so that the meat of
this change is separate from the mindless churn of that change.

Fix the testsuite fallout for error messages that change, and
in some cases, become more legible. Improve comments to better
match our intentions where a struct (rather than any complex
type) is required. Note that in some cases, an error message
now refers to 'struct' while the schema still refers to 'type';
that will be cleaned up in the later commit to the schema.

Backports commit fd41dd4eae5f7ea92f10c04cb3f217727fcee91f from qemu
2018-02-19 14:13:32 -05:00
Eric Blake 06faf280f1
qapi: More rigorous checking for type safety bypass
Now that we have a way to validate every type, we can also be
stricter about enforcing that callers that want to bypass
type safety in generated code. Prior to this patch, it didn't
matter what value was associated with the key 'gen', but it
looked odd that 'gen':'yes' could result in bypassing the
generated code. These changes also enforce the changes made
earlier in the series for documentation and consolidation of
using '**' as the wildcard type, as well as 'gen':false as the
canonical spelling for requesting type bypass.

Note that 'gen':false is a one-way switch away from the default;
we do not support 'gen':true (similar for 'success-response').
In practice, this doesn't matter.

Backports commit 2cbf09925ad45401673a79ab77f67de2f04a826c from qemu
2018-02-19 14:09:03 -05:00
Eric Blake 0b9d15dd52
qapi: Whitelist commands that don't return dictionary
...or an array of dictionaries. Although we have to cater to
existing commands, returning a non-dictionary means the command
is not extensible (no new name/value pairs can be added if more
information must be returned in parallel). By making the
whitelist explicit, any new command that falls foul of this
practice will have to be self-documenting, which will encourage
developers to either justify the action or rework the design to
use a dictionary after all.

It's a little bit sloppy that we share a single whitelist among
three clients (it's too permissive for each). If this is a
problem, a future patch could tighten things by having the
generator take the whitelist as an argument (as in
scripts/qapi-commands.py --legacy-returns=...), or by having
the generator output C code that requires explicit use of the
whitelist (as in:
then having the callers define appropriate macros). But until
we need such fine-grained separation (if ever), this patch does
the job just fine.

Backports commit 10d4d997f86cf2a4ce89145df5658952d5722e56 from qemu
2018-02-19 14:06:23 -05:00