Commit Graph

4 Commits

Author SHA1 Message Date
Copilot
aa8402d1b7 Python: wire match-pattern bindings into the shared CFG (green)
Adds concrete `Pattern` subclasses in `AstNodeImpl.qll` for every
`MatchPattern` AST kind, with `getChild` overrides that expose
sub-patterns and bound Names. Specifically:

- MatchCapturePattern (`case x:`) -> getVariable()
- MatchAsPattern (`case … as v:`) -> getPattern(), getAlias()
- MatchStarPattern (`case [*rest]:`) -> getTarget()
- MatchSequencePattern (`case [a, b]:`) -> getPattern(i)
- MatchClassPattern (`case Cls(p, q, k=v)`) -> getClass(), positional, keyword
- MatchMappingPattern (`case {k: v}:`) -> getMapping(i)
- MatchKeyValuePattern, MatchKeywordPattern, MatchDoubleStarPattern
- MatchOrPattern, MatchLiteralPattern, MatchValuePattern

Without these, every Name bound by a match pattern lacked a CFG node.
Removes the corresponding MISSING: annotations from match_pattern.py
(all 11 cases).

Verified: all 24 ControlFlow/evaluation-order tests still pass.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-05-12 13:11:18 +00:00
Copilot
0742e1e901 Python: wire parameters into the shared CFG (C# pattern)
Implements `AstSig::Parameter` and `callableGetParameter(c, i)` in
`AstNodeImpl.qll`, following the C# template
(`csharp/.../ControlFlowGraph.qll:147-156`) rather than Java's
`Parameter() { none() }`.

Each Python parameter (positional, *args, keyword-only, **kwargs) now
becomes a CFG node at a stable position in the enclosing callable's
entry sequence. Defaults still evaluate at function-definition time
via `FunctionDefExpr.getDefault` / `LambdaExpr.getDefault`, so
`Parameter::getDefaultValue()` returns `none()` (the shared CFG
library calls this to model the missing-argument fallback, which
Python does not surface at the CFG level).

The bindings test now exercises parameters (the `py_expr_contexts(_, 4, ...)`
exclusion has been removed). A new `parameters.py` test case covers
positional, defaulted, vararg, kwarg, keyword-only, kitchen-sink,
method (self/cls), lambda, and PEP 570 positional-only parameters.
Several other test files were updated to annotate parameters that the
test had previously hidden (synthetic `.0` comprehension parameter,
method `self`, decorator `f`, etc.).

Verified:
- All 24 ControlFlow/evaluation-order tests still pass.
- CFG consistency query (`python/ql/consistency-queries/CfgConsistency.ql`)
  shows zero violations on CPython.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-05-12 12:29:28 +00:00
Copilot
a20af3cf41 Python: wire AnnAssign into the shared CFG (green)
Adds an `AnnAssignStmt` wrapper in `AstNodeImpl.qll` so that PEP 526
annotated assignments (`x: int = 1`, `x: int`) participate in the
control flow graph. Evaluation order follows CPython: annotation,
optional value, target binding.

Without this, `x: int = 1` had no CFG node for `x` even though
`Name.defines(v)` returns true for it on the AST side. SSA built on
the new CFG would therefore miss every annotated-assignment write.

Removes the corresponding MISSING: annotations from the CFG-binding
gap test:
- annassign.py — all four cases now green.
- match_pattern.py — class-body annotated fields (`x: int`, `y: int`).
- type_params.py — `item: T` inside class.

Verified: all 24 ControlFlow/evaluation-order tests still pass.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-05-12 12:22:57 +00:00
Copilot
f077e7c27c Python: add CFG-binding gap tests (red)
Adds inline-expectation tests for the new shared CFG implementation in
python/ql/lib/semmle/python/controlflow/internal/AstNodeImpl.qll,
covering every Python binding construct that introduces a variable.

The test files use MISSING: annotations to record bindings whose
defining Name AST node is *not* currently reachable from the new CFG.
These are the 'red' half of red-green commit pairs: subsequent commits
will extend AstNodeImpl to cover each construct and remove the
corresponding MISSING: marker.

Confirmed-broken categories:
- Import aliases (from x import a)
- Annotated assignment (x: int = 1)
- Exception handler (except E as e)
- Match patterns (case x, case [a,b], case ... as v)
- PEP 695 type params (def f[T], class C[T])

Confirmed-working (no MISSING:):
- Compound targets, with-as, comprehensions, decorated def/class,
  walrus, starred.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-05-12 12:19:34 +00:00