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
2022-10-20 08:21:02 -04:00
2026-03-16 08:51:51 +01:00
2026-04-24 13:24:31 +02:00
2026-02-10 13:44:04 +01:00
2018-09-23 16:24:31 -07:00
2025-09-25 14:03:39 +01:00
2025-09-30 10:21:17 +02:00
2025-10-23 10:49:51 +02:00
2022-04-12 12:40:59 +02:00
2024-05-07 13:09:08 +01:00

CodeQL

This open source repository contains the standard CodeQL libraries and queries that power GitHub Advanced Security and the other application security products that GitHub makes available to its customers worldwide.

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CodeQL: the libraries and queries that power security researchers around the world, as well as code scanning in GitHub Advanced Security
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