ParserStatus is now more lightweight, and doesn't know about "result"
and "from cache". Instead, it has an isValid() method which is merely a
shorthand for checking whether getException() is null.
Introduce a child class, RuleCheckerStatus, which knows about result and
cache and can be (un)serialized.
This removes the ambiguity of the $result field, and helps the
transition to a new RuleChecker class.
Change-Id: I0dac7ab4febbfdabe72596631db630411d967ab5
Something somewhere is leaving error_reporting in a dirty state
causing AbuseFilter's ConsequencesExecutorTest case to fail for
the core change Ic9fee6cdd88001025.
Per T253461, we're meant to eventually remove this anyway, so might
as well remove it in areas that are known to get it wrong somehow.
Change-Id: I2a665f09a357f2f2cc258d8c4011d49a7ab9c13b
The old parser now has the correct name "Evaluator", so the
ParserFactory name was outdated. Additionally, the plan is to create a
new RuleChecker class, acting as a facade for the different
parsing-related stages (lexer, parser, evaluator, etc.), which is what
most if not all callers should use. The RuleCheckerFactory still returns
a FilterEvaluator for now.
Also, "Parser" is a specific term defining *how* things happen
internally, whereas "RuleChecker" describes *what* callers should expect
from the new class.
Change-Id: I25b47a162d933c1e385175aae715ca38872b1442
Remove unnecessary setters, injecting everything in the constructor.
These were leftovers from before the introduction of ParserFactory.
Remove public access to the conds used, include the information inside
the returned ParserStatus instead, and consequently simplify callers.
Change-Id: I0a30e044877c6c858af3ff73f819d5ec7c4cc769
This commit adds a class AFPSyntaxChecker which can statically analyze
a filter code to detect the following errors:
- unbound variables (which comes in two modes: conservative and liberal,
default to conservative)
- unused variables (disabled by default for compatibilty)
- assignment on built-in identifiers
- function application's arity mismatch
- function application's invalid function name
- non-string literal in the first argument of set / set_var
The existing parser and evaluator are modified as follows:
- The new (caching) evaluator no longer needs to perform variable
hoisting at runtime.
- Note that for array assignment, this changes the semantics.
- The new parser is more lenient, reducing parsing errors.
The static analyzer will catch these errors instead, allowing us
to give a much better error message and reduces the complexity of
the parser.
* The parser now allows function name to be any identifier.
* The parser now allows arity mismatch to occur.
* The parser now allows the first argument of set to be any expression.
Concretely, obvious changes that users will see are:
1. a := [1]; false & (a[] := 2); a[0] === 1
would evaluate to true, while it used to evaluate to the undefined value
due to hoisting
2. f(1)
will now error with 'f is not a valid function' as opposed to
'Unexpected "T_BRACE"'
3. length
will now error with 'Illegal use of built-in identifier "length"'
as opposed to 'Expected a ('
Appendix: conservative and liberal mode
The conservative mode is completely compatible with the current evaluator.
That is,
false & (a := 1); a
will not deem `a` as unbound, though this is actually undesirable because
`a` would then be bound to the troublesome undefined value.
The liberal mode rejects the above pattern by deeming `a` as unbound.
However, it also rejects
true & (a := 1); a
even though (a := 1) is always executed. Since there are several filters
in Wikimedia projects that rely on this behavior, we default the mode
to conservative for now.
Note that even the liberal mode doesn't really respect lexical scope
appeared in some other programming languages (see also T234690).
For instance:
(if true then (a := 1) else (a := 2) end); a
would be accepted by the liberal checker, even though under lexical scope,
`a` would be unbound. However, it is unlikely that lexical scope
will be suitable for the filter language, as most filters in
Wikimedia projects that have user-defined variable do violate lexical scope.
Bug: T260903
Bug: T238709
Bug: T237610
Bug: T234690
Bug: T231536
Change-Id: Ic6d030503e554933f8d220c6f87b680505918ae2
Create a dedicated "Exception" sub-namespace and remove the "AFP"
prefix, a leftover from the pre-namespace era.
Change-Id: I7e5fded9316d8b7d1628bc1a6ba8b1879ac901e1
All methods were moved to the new parser. Tests and other pieces were
adjusted to expect just a single parser. There are still some TODOs
(remove AFPTransitionBase, remove $this->mCur), but these are left for
another commit.
Note that the new parser was not renamed: this is because the names are
wrong anyway (CachingParser is more of an Evaluator than a Parser, and
AFPTreeParser is the real parser, and should be renamed as well).
NOTE to reviewers: this patch looks quite big, but if you diff the old
parser with the new version of the CachingParser, you'll notice that the
diff is actually small, since everything was basically copied verbatim.
Bug: T239990
Change-Id: Ie914ef64c70503a201b4d2dec698ca2fa8e69b10
1 - Change the structure of if/elseif for readability
2 - In the old parser, if there's an empty argument, never add it (the
new parser was already doing that).
Bug: T156095
Bug: T156096
Change-Id: I4237b1a0ba01e7ce04dcc945f7daf34612fcf07d
Introduce a clear distinction between internal exceptions and
user-visible exceptions, leaving AFPException as base abstract class.
Later, it should be possible to narrow some types around, e.g. in
ParserStatus (that might work with user-visible exceptions only).
Also a future TODO is putting all the exceptions in their own namespace
(probably ...\Parser\Exception).
Change-Id: I4e33a45117f0a3e73af03cc1e3f2734beaf2b5e1
Thanks to this, we will be able to provide more information
to consequences and watchers, which will open door for new
features and possibly cleaner code.
Change-Id: I7135509823ea84b2a2923d2c1831ce293b98a9f9
It was changed to use AFPData::toNative, so it no longer returns a
string. Instead, it can return any PHP native type.
Change-Id: I92eba03a5fa1149860634a97318b5b15807eb5a5
Also add a bunch of tests for this function.
REMINDER: Change the docs on mw.org when this will be merged.
Bug: T218074
Depends-On: I155024341e8e6b13240e37b30c31b95dc83a47e0
Change-Id: I979e45110bc0e76b499679184993085062ffcac5
This makes VariableHolder a true value object, and introduces a
stateless service, VariableManager, to operate on it.
Note, in theory, this new service is still cyclically coupled with
LazyVariableComputed. However, it's now two stateless service being
coupled, not two smart/god value objects, so we've still earned
something. For now, the dependency is hidden by using a callback. Some
alternatives for that are mentioned in a code comment.
Bug: T261069
Change-Id: I2f2c84c8e91472ba36084a8bbb4a923f6e04354b
This commit introduces some boilerplate for emitting warnings from the
AbuseFilter parser, and also code for showing these warnings in the ace
editor. Adding new warnings should be as simple as appending to
AbuseFilterParser::warnings (and adding the relevant i18n).
Bug: T264768
Bug: T269770
Change-Id: Ic11021b379f997a89f59c8c0572338d957e089a6
This is achieved by creating a new ParserStatus class. Aside from the
result of parse(), it contains whether the cache was warm. This can be
used to differentiate profiling data as part of T231112.
Another use case is returning non-fatal warnings (T269770).
Change-Id: Ifcbda861ce1a44bbe9bffba5b83cd9ef338a8dba
