Sweep the last few uses of legacy AstNode.getAFlowNode() in tests over to
explicit ControlFlowNode joins after the shared-CFG migration. importflow.ql
needs the new Cfg::ControlFlowNode/CompareNode types because DataFlow::Node.
asCfgNode() now returns the shared-CFG node.
Also extend ImportResolution::allowedEssaImportStep to walk back through
uncertain-write SSA inputs, so that a later 'from X import *' does not hide
the preceding explicit (re)assignment from module-export resolution. Without
this, a reassigned name that survives a wildcard import was no longer
recognised as the module export. Rebless ModuleExport.expected to drop the
legacy 'ControlFlowNode for' toString prefix and pick up the two correct rows
exposed by the fix.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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>
