Files
codeql/python/ql/lib
yoff ccfaa6ea7f Python: migrate dataflow library to new CFG + shared SSA
Switches the trunk dataflow library and all in-tree consumers
(frameworks, ApiGraphs, Concepts, regexp, security customisations,
test harness) from the legacy Flow.qll/ESSA stack to the new
shared-CFG facade (Cfg.qll) and the ESSA-shaped adapter on the
shared-SSA library (SsaImpl.qll).

Highlights:

  * DataFlowPublic/Private/Dispatch, Attributes, VariableCapture,
    IterableUnpacking, ImportResolution, ImportStar, LocalSources,
    TaintTrackingPrivate, MatchUnpacking, TypeTrackingImpl,
    SsaImpl, Builtins all now qualify CFG/SSA references with
    Cfg:: / SsaImpl:: and stop pulling in semmle.python.essa.*.

  * AstNodeImpl.qll/Cfg.qll: ImportMember exposes its inner
    ImportExpr, DefinitionNode.getValue covers Alias / AnnAssign /
    AugAssign / AssignExpr / For-target / Parameter-default,
    ForNode is treated as an expression node, AnnotatedExitNode is
    canonical, and BoolExprNode.getAnOperand drops the dominance
    constraint that did not hold for short-circuit BBs.

  * SsaImpl.qll: parameters always get a ParameterDefinition (so
    unused parameters still have SSA defs), scope-entry defs for
    module globals require an actual store somewhere, scope-exit
    has a synthetic use so reaching-defs survives to module
    boundary, and the legacy SsaSourceVariable / EssaVariable
    surface (getName, getScope, getAUse, getASourceUse,
    getAnImplicitUse) is reinstated for downstream queries.

  * DataFlowPublic.qll: GuardNode redesigned around the new
    structural outcome nodes (isAfterTrue / isAfterFalse).  The
    legacy ConditionBlock + flipped indirection is gone;
    controlsBlock walks UP through 'not' / '==True' / 'is False'
    etc. via outcomeOfGuard, accumulating polarity cleanly.  Only
    BarrierGuard<...> is preserved as public API.

  * ModuleVariableNode.getAWrite and LocalFlow::definitionFlowStep
    bypass SSA and consult Cfg::NameNode.defines /
    Cfg::DefinitionNode.getValue directly, so that write defs
    pruned by shared SSA (because the variable has no in-scope
    read) still produce dataflow steps.

  * Frameworks + downstream consumers: replace
    EssaVariable.hasDefiningNode, getAReturnValueFlowNode,
    Parameter.getDefault, Scope.getEntryNode / getANormalExit etc.
    with CFG-side bridges through Cfg::ControlFlowNode.

The legacy Flow.qll / Essa.qll stack is untouched and remains
available for queries that import it directly.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-05-26 07:20:44 +00:00
..
2024-04-16 16:29:56 +02:00