Second batch of test reblessings, capturing changes in result content
(not just toString labels):
- Framework taint/concept tests (fastapi, sqlalchemy, aiohttp, lxml,
stdlib, django-orm): mostly gained MISSING-tainted annotations where
the new dataflow no longer reaches sinks. Some are real taint
regressions; left as documented failures for follow-up.
- Exception-handler tests (CWE-209-StackTraceExposure, EmptyExcept,
CatchingBaseException, IncorrectExceptOrder, FileNotAlwaysClosed,
FindSubclass/Find, Statements/exit/UseOfExit): the no-raise shared CFG
abstraction does not emit ExceptionSuccessor abrupt-completion edges
from arbitrary expressions, so except-handler bodies (and their
exception target Names) are statically dead. Tracked separately under
cfg-modelling-exceptions.
- Dataflow-path / control-flow node toString polish across the security
query suite (PathInjection, CodeInjection, UnsafeUnpacking,
UnsafeUsageOfClientSideEncryptionVersion, RequestWithoutValidation,
ReflectedXss, CallGraph): simple-leaf nodes now stringify as their
AST text instead of 'After X'.
- SSA / call-graph improvements (CmpTest, CallGraph/InlineCallGraphTest):
fewer SSA mismatches between new and old; two previously-MISSING tt=
annotations resolved.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The new SSA's implicit entry-def predicate previously placed entries in
the variable's defining scope. For closure variables that's the outer
function, so inner functions had no entry def for the captured
variable — reads in the inner scope failed to resolve to any
definition.
Mirrors legacy ESSA's 'NonLocalVariable.getScopeEntryDefinition()':
place an implicit entry def at every reading scope's entry block,
independently of where the variable is *defined*. A closure variable
accessed in two nested functions and the outer one gets three entry
defs (one per reading scope).
Also makes 'ScopeEntryDefinition' extend 'EssaNodeDefinition' (matching
legacy ESSA), with 'getDefiningNode()' returning the scope's entry CFG
node. This requires extending the private 'writeDefNode' helper to
project i=-1 entries to bb.getNode(0).
Updates the new-vs-legacy comparison snapshot: closure-variable reads
('x:32:5'), nested global reads ('GLOBAL:52:1') now resolve. New
'def-only-new' entries appear for unbound names ('sum', 'open',
'compute') — the new SSA uniformly creates scope-entry defs for all
non-local reads, including those that legacy ESSA classifies as
builtin and excludes. This is a more uniform semantic and arguably
cleaner.
Updates the SsaTest 'some_undefined' annotation: previously documented
as a known limitation, now correctly resolves to a scope-entry def.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Adds 'python/ql/lib/semmle/python/dataflow/new/internal/SsaImpl.qll', a
minimal Python SSA implementation built on the shared SSA library
('codeql.ssa.Ssa::Make<Location, Cfg, Input>'). The structure mirrors
Java's adapter at 'java/ql/lib/semmle/code/java/dataflow/internal/SsaImpl.qll'.
Key design choices:
* 'SourceVariable' wraps 'Py::Variable'. Only variables that are read
or deleted somewhere are tracked - write-only variables don't
benefit from SSA construction.
* Variable references are positional ('BasicBlock', 'int') pairs
looked up via 'Cfg::NameNode.defines'/'.uses'/'.deletes' (which
themselves are one-line bridges to AST-level 'Name.defines' etc.).
* Parameter writes are not synthesised: parameter Name nodes are
already wired into the CFG (per the earlier C#-style parameter
extension in 'AstNodeImpl.qll'), so the regular 'variableWrite'
path handles them at their natural CFG index.
* Non-local / captured / global / builtin variables read in a scope
but not written in it receive a synthetic entry definition at
index '-1' of the scope's entry basic block. This matches Java's
'hasEntryDef'.
* 'del x' is modelled as a certain write at the deletion site.
Includes an inline-expectations test under
'python/ql/test/library-tests/dataflow-new-ssa/' covering:
plain parameter pass-through, simple assignment + read, reassignment
with dead-write pruning, if/else with phi insertion at the join, and
an undefined-name read (currently a known limitation - no SSA flow
without an enclosing definition).
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
