Preparatory refactor for the shared-CFG dataflow migration. Adds the
new Python CFG library additively, without changing any production
behaviour.
Library additions:
- semmle.python.controlflow.internal.AstNodeImpl — mediates between
the Python AST and the shared codeql.controlflow.ControlFlowGraph
signature. Wraps Python's Stmt/Expr/Scope/Pattern and adds two
synthetic kinds of node (BlockStmt for body slots, intermediate
nodes for multi-operand boolean expressions).
- semmle.python.controlflow.internal.Cfg — public facade
re-exposing the same API surface as semmle/python/Flow.qll
(ControlFlowNode, CallNode, BasicBlock, NameNode, DefinitionNode,
CompareNode, ...), backed by the shared CFG.
- lib/printCfgNew.ql — debug/visualisation query for the new CFG.
- consistency-queries/CfgConsistency.ql — consistency query running
the shared CFG's standard checks against Python.
Shared library:
- shared.controlflow.ControlFlowGraph — adds two defaulted
getWhileElse / getForeachElse predicates to AstSig so Python can
model while-else / for-else (no behavioural change for other
languages).
Test additions:
- ControlFlow/bindings/* — annotation-driven SSA-binding tests for
the new CFG (annassign, compound, comprehension, decorated,
except_handler, imports, match_pattern, parameters, simple,
type_params, walrus_starred, with_stmt, dead_under_no_raise).
- ControlFlow/store-load/* — basic store/load coverage.
- ControlFlow/evaluation-order/NewCfg*.ql — mirrors of the existing
OldCfg evaluation-order self-validation suite, run against the
new CFG via NewCfgImpl.qll.
- Minor extensions to existing test_if.py / test_boolean.py +
cosmetic .expected churn on a handful of OldCfg tests.
No dataflow, SSA, or production query is migrated yet — that lands in
follow-up PRs. The new CFG library has zero callers in lib/ and src/.
Verified by:
- All lib + src + consistency-queries compile clean (367 queries).
- All 56 ControlFlow library-tests pass.
- All 474 dataflow + PointsTo library-tests + consistency tests pass.
- syntax_error/CONSISTENCY/CfgConsistency passes.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Follow-up to the getAFlowNode deprecation in the same PR: same AST→legacy-CFG
bridge pattern. The 11 internal call sites (across objects/, types/,
frameworks/, and TypeTrackingImpl) are rewritten to bind a `Return ret`
explicitly, then constrain via `ret.getScope() = f and n.getNode() = ret.getValue()`.
The predicate itself is preserved with a deprecation note so external
users do not experience churn.
Semantic noop.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Preparatory refactor for the shared-CFG dataflow migration.
Deprecates the AstNode.getAFlowNode() cached predicate on the public
Python QL API and rewrites all ~140 internal callers across lib/, src/,
test/, and tools/ from `expr.getAFlowNode() = cfgNode` to
`cfgNode.getNode() = expr`, using ControlFlowNode.getNode() which
already exists in Flow.qll.
The predicate itself is preserved (with a deprecation note pointing at
the new pattern) so external users do not experience churn — they can
migrate at their own pace and the AST/CFG hierarchies still get the
intended untangling once the deprecation eventually elapses.
Semantic noop verified by:
- All 361 lib/ + src/ queries compile clean.
- All 122 ControlFlow + PointsTo library-tests pass.
- All 64 dataflow library-tests pass.
- All 113 Variables/Exceptions/Expressions/Statements/Functions/Imports/
Security/CWE-798/ModificationOfParameterWithDefault query-tests pass.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The internal predicates that identify `@staticmethod`, `@classmethod` and
`@property` decorators previously required the decorator's `NameNode` to
satisfy `isGlobal()` (i.e. no SSA def reaches the decorator's name use).
That filter was correct but unnecessarily indirect: these three names
are builtins, and even when a class body redefines one, the class body
has not started executing at the decorator position, so Python uses the
builtin.
Match the decorator's AST `Name` directly instead, dropping the CFG/SSA
detour. The slight semantic change — `isGlobal()` would have rejected
module-level shadowing of these builtins — is negligible in practice
and explicitly documented in the change note.
`hasContextmanagerDecorator` and `hasOverloadDecorator` keep the
`NameNode.isGlobal()` check because their target names (`contextmanager`,
`overload`) are imported, not builtin, and local shadowing is a real
concern.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
