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Author SHA1 Message Date
azizur100389
3dd553b345
feat(taint): expand TS/JS sink model (#2490)
* feat(taint): expand TS/JS sink model

Co-authored-by: Cursor <cursoragent@cursor.com>

* test(taint): cover TS sink disambiguation end-to-end

Add a real-pipeline integration test proving the expanded TS/JS taint sinks only emit findings for intended imported and receiver-conventional symbols.

Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Gergő Magyar <gergomagyar@icloud.com>
2026-07-16 13:11:57 +01:00
Gergő Magyar
7c3d4e6862
feat(pdg): control dependence — post-dominators + CDG (Ferrante) [M5 #2085] (#2188)
* feat(pdg): add CDG + POST_DOMINATE edge types (M5 #2085)

* feat(pdg): post-dominator tree on reverse CFG (M5 #2085)

* feat(pdg): Ferrante control-dependence over the post-dom tree (M5 #2085)

* feat(pdg): emitFileCdg + optional POST_DOMINATE debug edges (M5 #2085)

* feat(pdg): wire CDG emission in-phase + pdgModeMismatch CDG-cap stamp (M5 #2085)

* test(pdg): CDG snapshot + end-to-end pipeline answerability (M5 #2085)

* fix(review): apply autofix feedback (M5 #2085)

* fix(pdg): label CDG edges by controller arm sense, not edge kind (#2188 F1/F2/F4)

Tri-review (with Codex as the independent engine) found the CDG 'T'/'F' label
was wrong for the commonest control flow: the M1 TS visitor wires a condition's
fall-through FALSE arm as `seq`/`loop-back`, but `branchSense` mapped both to
'T', so guard clauses, if-no-else, and loop `break` got 'T' instead of 'F' (F1,
P1). The structural CDG edges were correct; only the label — the AC3 "under what
condition does X run?" answer — was wrong.

- F1: replace edge-kind `branchSense` with controller-arm-sense `labelFor`. An
  ambiguous fall-through edge (seq/loop-back) takes the COMPLEMENT of its source
  block's explicit cond-true/cond-false sibling arm. This correctly handles
  do/while (loop-back = TRUE arm) and inner-if-in-loop (loop-back = FALSE arm) —
  the ambiguity a kind→label table cannot resolve. Adds real-parser regression
  tests (the hand-built tests used a fictional cond-false edge and missed it).
- F2: correct the false "sound over-approximation that never drops a real
  dependence" claim in post-dominators.ts — exit-unreachable regions both drop
  and invent control dependences (latent for the current TS visitor, which keeps
  EXIT reverse-reachable). Reframe the exit-less-loop test to characterize, not
  bless, the degenerate behavior.
- F4: make the AC2 property-test reference compute post-dominance INDEPENDENTLY
  (node-removal reachability, no shared code with post-dominators.ts), so a
  post-dom direction bug can no longer pass both the impl and the reference.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(ci): root-prettier format + run-analyze pdg stamp gains maxCdgEdgesPerFunction (#2085)

Two deterministic CI failures from the M5 CDG work:
- quality/format: basicblock-roundtrip.test.ts failed CI's root `prettier --check .`
  (the pre-commit hook uses the gitnexus-local prettier config, which differs);
  reformatted with the root config.
- tests/ubuntu/coverage: run-analyze.test.ts pinned the resolved RepoMeta.pdg
  shape (DEFAULTS) and the all-zero cap override without the new
  maxCdgEdgesPerFunction key (default 5000); added it so resolvePdgConfig
  toEqual and pdgModeMismatch(DEFAULTS) pass. (The stale-test sweep missed this
  file in PR #2188 — same trap M2 hit.)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* feat(mcp): add pdg_query tool definition (controls/flows modes) [M6 #2086]

* feat(mcp): pdg_query backend — controls (CDG) + flows (REACHING_DEF) + e2e test [M6 #2086]

* feat(mcp): document PDG edges + pdg_query (schema, cypher, skill, --pdg-gated ai-context) [M6 #2086]

* fix(mcp): correct pdg_query symbol-anchor lower bound + harden inputs [PR #2188 review]

Tri-review (Codex + adversarial + correctness lanes) of the M6 pdg_query
surface found the symbol-anchor window over-includes a neighbor function's
block. The upper bound was widened to the 1-based BasicBlock basis (symEnd+1)
but the lower bound was left 0-based, so a block on the line directly above the
target function leaked into the result. Shift both bounds +1 ([symStart+1,
symEnd+1]) so the window is the function's true block span.

Also from the same review:
- pdg_query no longer throws on a no-arguments MCP call: the dispatch passes
  raw `params`, so default it to {} → a clean mode-validation error instead of
  a TypeError. (`explain` shares this latent pattern — pre-existing follow-up.)
- tools.ts: the controls-mode description no longer hard-codes the 'F' branch
  sense for guards — `if (!ok) return;` rides the predicate's 'T' arm; the
  guard:true flag is label-agnostic (regex on the dependent block text).

Tests: a hand-seeded adjacency regression (verified failing without the
lower-bound +1) + a no-arguments validation test. Skill doc updated to document
the two-sided [symStart+1, symEnd+1] window.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(mcp): drop always-true anchor conditional in pdg_query [CodeQL #2188]

CodeQL alert 756 flagged `...(anchor ? { anchor } : {})` in _pdgQueryImpl as a
useless conditional: `anchor` is unconditionally assigned in both the file-path
and symbol branches before the return (the not-found/ambiguous/no-layer paths
return earlier), so it is always truthy. Drop `| undefined` from the declaration
(TypeScript definite-assignment holds across both branches) and emit `anchor`
directly.

No runtime change — the `anchor` field was already present on every result.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* test(cli): add hasPdg to the noStats bridge expectation [#2188]

The M6 work threaded `hasPdg: options.pdg === true` into the AIContextOptions
passed to generateAIContextFiles on the --skills regeneration path, but this
test's strict .toEqual expectation predated it (4 keys vs 3 → CI failure). Add
`hasPdg: false` (the value on this non---pdg path). The assertion stays strict;
the #1477 noStats bridging it guards is unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* refactor(cli): collapse generateGitNexusContent params to an options bag [#2188]

The function had grown to 9 positional params; reaching `hasPdg` meant passing
six `undefined`s (the M6 review's maintainability flag). Collapse params 3-9
(generatedSkills, groupNames, noStats, skipSkills, runnerPath, defaultBranch,
hasPdg) into a `GitNexusContentOptions` object with the defaults moved to
destructuring. The body is unchanged (same local names); the single production
caller and the test calls become self-documenting named fields.

Pure refactor — generated AGENTS.md/CLAUDE.md content is byte-identical.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(cfg): skip CDG for exit-unreachable CFGs (unsound post-dominance) [#2188]

M5 review P2: computePostDominators roots only at cfg.exitIndex and nothing
enforced that EXIT is reachable from every block. For an entry-reachable region
that cannot reach EXIT (a non-terminating loop, or a multi-terminal CFG a future
visitor might emit) the EXIT-rooted reverse walk degenerates — it both drops
real control dependences and invents spurious ones.

Add a pure precondition predicate `isExitReachableFromAllBlocks` (co-located with
the algorithm it guards) and gate it in emitFileCdg: a CFG that violates it is
skipped for CDG (counted as skippedUnsoundFunctions + one onWarn), while its CFG
and REACHING_DEF projections — which do not depend on post-dominance — are kept.
A CDG-specific gate, not a widening of isEmitSafeCfg, so the blast radius is
exactly the unsound CDG. The current TS visitor always satisfies the
precondition (every loop gets a structural header→loopExit edge), so CDG output
for real fixtures is unchanged.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(cfg): bound computeControlDependence materialization (heap parity) [#2188]

M5 review P2: unlike computeReachingDefs (maxFacts) and the emit-side edge cap,
computeControlDependence materialized the full deduped seen/out before
emitFileCdg's per-function cap could trim it — O(edges × post-dom depth) heap
for a deeply nested function.

Add a `maxEdges` ceiling (default 0 = unbounded) returning {edges, truncated},
mirroring computeReachingDefs's {facts, truncated}. The ceiling is checked
before pushing a new unique edge, so `truncated` means a genuine overflow (not
merely "reached cap"). emitFileCdg passes a FIXED materialization ceiling (8× the
default edge cap) — deliberately NOT derived from the runtime edge cap, because
CDG's materialization IS the deduped-edge quantity the cap reports on (deriving
it would pre-truncate that set and lose the exact dropped count). A ceiling hit
is surfaced via onWarn + the truncated flag — never silent.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* refactor(mcp): share resolveBlockAnchor; fix explain's anchor off-by-one [#2188]

M6 review P2 (duplication) + the flagged pre-existing _explainImpl correctness
follow-up. _pdgQueryImpl and _explainImpl each carried a near-identical
symbol↔block anchor resolver that had DRIFTED: pdg_query used the corrected
[symStart+1, symEnd+1] window (BasicBlock startLine is 1-based, the symbol span
0-based) while _explainImpl still used [symStart, symEnd] — dropping a taint
source on the function's final line AND leaking a neighbor's block on the line
directly above.

Extract one `resolveBlockAnchor` helper, used by both, that applies the correct
window and a single (bare) clause convention (callers compose their own WHERE).
This removes ~50 duplicated lines and fixes explain's anchor in one place.

A hand-seeded characterization test (taint-explain Block 4) pins both bounds —
verified to FAIL on the pre-fix window (it returned the line-10 neighbor instead
of the line-15 final-line source). Existing taint-explain + pdg-query suites are
unchanged (their fixtures have interior sources/sinks).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* fix(mcp): pdg_query reports "status unknown" when the layer can't be confirmed [#2188]

M6 review P3 (Codex): when meta is UNREADABLE and the bounded global existence
probe returns zero rows of the edge type, _pdgQueryImpl asserted "no PDG layer"
— but a genuinely edge-free layer (all-linear functions) is indistinguishable
from a missing one via that probe. Soften only that fallback path to an
inconclusive "PDG layer status unknown — was this repo indexed with --pdg?"
note. The meta-stamped path (stamp present, cap absent ⇒ layer truly missing)
keeps the definitive "no PDG layer" wording.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* test(mcp): cover pdg_query ambiguous / pagination / Windows-path gaps [#2188]

M6 review test-gap follow-ups, all hand-seeded with controlled data:
- ambiguous symbol name → status:'ambiguous' + ranked candidates shape
  (uid/name/filePath/score), never a silent guess;
- total/truncated page boundary in both directions (limit below the match count
  sets truncated with the full total; limit above it omits truncated);
- a Windows-style filePath containing ':' resolves and fnLineOf decodes the
  function-line segment correctly (split-from-right past the drive letter).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* docs(skills): ship gitnexus-pdg-query skill mirrors + add pdg_query to the guide [#2086]

M6 bundled pdg_query into this PR, but the skill shipped only in the canonical
gitnexus/skills/ root. Mirror it (byte-identical) to the two hand-maintained
roots the sibling taint skill uses — .claude/skills/gitnexus/ and the plugin —
so Claude Code + plugin users get it too.

Also extend the gitnexus-guide tool reference (all 3 copies, now byte-identical):
add a `pdg_query` row + a "Control & data dependence" section mirroring the
taint/`explain` section, and reconcile the pre-existing drift where only the
.claude copy carried the `check` tool row (a real registered tool) — all three
now list it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* docs(architecture): refresh CFG/PDG section for the full M1–M6 stack [#2086]

The PR body had deferred the "ARCHITECTURE docs refresh" to #2086; now that M6
ships here, do it:
- MCP tools table gains `explain` and `pdg_query` (were absent).
- "Optional CFG/PDG emission" was M1-only; rewrite to cover the whole opt-in
  stack — M1 CFG, M2 REACHING_DEF, M3/M4 taint, M5 CDG (Ferrante over CHK
  post-dominators, with the exit-unreachable skip), M6 read surface (pdg_query +
  explain, anchored + LIMIT-bounded, shared resolveBlockAnchor) — and note the
  no-Function→BasicBlock-edge join.
- LadybugDB schema notes the `--pdg` additions: the `BasicBlock` node table and
  the CFG/REACHING_DEF/CDG/TAINTED/SANITIZES/TAINT_PATH relation types, kept out
  of the default VALID_RELATION_TYPES / web schema.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-13 18:49:03 +01:00
Gergő Magyar
129bc84c0d
feat(taint): interprocedural taint via function summaries over resolved CALLS (#2084) (#2179) 2026-06-13 07:04:14 +01:00
Gergő Magyar
14397dd4aa
feat(taint): intra-procedural taint analysis (#2083) (#2164)
* feat(taint): harvest occurrence-tagged call/member sites on StatementFacts (#2083 U1)

Worker-side site harvest in TsHarvester: call/new/member-read records with
dotted callee paths, receiver slots, per-argument occurrence tagging with
nested-site links, per-declarator resultDefs, spread/template/require-literal
markers. hasTaintSafeSites validation seam. The pdg parse-cache chunk-key
namespace is versioned (pdg:1 -> pdg:2) instead of a global SCHEMA_BUMP so
flag-off users keep warm caches; bench fingerprints re-baselined for the
three call-bearing scenarios (straight-line/dense-bindings byte-unchanged).

* feat(taint): built-in TS/JS source/sink/sanitizer model + site matcher (#2083 U2)

Typed spec (kind taxonomy; sanitizers carry neutralizes-kinds), the canonical
Express/Node model, and matchFunctionSites: ESM alias/namespace + require-
literal callee resolution, bare-name fallback restricted to true globals,
sanitizers module-or-global only (never user-shadowable by name), spread/
template arg-position rules, deterministic taintModelVersion.

* feat(taint): pure intra-procedural taint propagation engine (#2083 U3)

Two-rule model (statement-local + du-fact worklist) with per-taint
neutralized-kind exclusion sets: sanitizers exclude only the sink kinds
they neutralize (escape(req.body) suppresses res.send but still fires
db.query; exec(path.basename(t)) fires), intersection-over-paths so a
bypass occurrence keeps the taint live, kill locality on resultDefs,
propagate-through args+receiver with viaCall hops, one path per finding,
deterministic caps, coverage-gap statuses. Test-first: 38 scenarios on
real harvested CFGs.

* feat(taint): thread taint caps + model version through pdg config/meta (#2083 U5)

resolvePdgConfig gains maxTaintFindingsPerFunction (200), maxTaintHops (32),
and the taintModelVersion digest; RepoMeta.pdg + RunScopeResolutionInput
surfaces added. The key-union comparator trips full writeback on M2->M3
upgrade and on model-version change without --force (mode-flip tested).
No CLI flags or rc keys (programmatic parity with the other caps).

* feat(taint): in-phase taint emit with sparse TAINTED/SANITIZES edges (#2083 U4)

run.ts pdg window: match-first fast path (solver only when a function has
both a matched source and sink) -> computeReachingDefs with the shared RD
fact derivation -> computeTaintFlows -> per-finding TAINTED (versioned
hop-encoded reason via the shared path codec, statement-level occurrence
identity) + per-kill SANITIZES, dedup-before-budget, truncate-and-warn.
All emit counters surfaced (aggregate warn for gaps/drops, debug for
volume); PROF gains taint=. Flag-off golden untouched.

* feat(mcp): explain tool for persisted taint findings (#2083 U6)

Anchorless calls enumerate the sparse TAINTED table (bounded, deterministic,
limit-clamped); anchored calls (file or symbol via resolveSymbolCandidates)
return full decoded hop detail. sinkKind rides a version-1 codec header
(1;<kind>|hops — no other persisted channel exists; U4/U6 ship together).
RepoMeta.pdg probe yields a no-taint-layer note instead of an error.
TAINTED/SANITIZES pinned OUT of VALID_RELATION_TYPES (KTD9a negative-
membership tests); generators + canonical skill docs + mirrors updated.

* test(taint): acceptance fixture battery, snapshots, and bench gates (#2083 U7)

pdg-repo taint-cases fixtures complete the six plan shapes; committed
findings/kills snapshot via a shared pure-path harness that also feeds the
AE2 exact-equality assertion (stored TAINTED == pure-path findings, the
no-explosion gate). New taint-dense bench scenario with four --check gates:
per-function findings pinned AT the cap, absolute reason-byte + site-bytes
disk ceilings (the load-bearing R10 gate), zero-match pass < 0.5x match-
dense, N-linearity. Pre-existing scenario baselines untouched.

* refactor(taint): share one pointKey helper across propagate + emit (#2083 review)

Extract pointKey(ProgramPoint) to cfg/reaching-defs.ts (colon-separated,
matching the codebase block:stmt id convention) and import it in both
propagate.ts and emit.ts, replacing the two divergent locals (':' vs '.').
Edge-id material now uses the colon form; ids are in-memory only and no
test asserts the pointKey segment shape.

* fix(taint): discriminate taint state by source occurrence (#2083 review)

Two distinct sources flowing into one variable at one def point no longer
collapse to a single TAINTED edge: the taint-state key gains a root
source-occurrence discriminator ({point, siteIndex} — the same fields
recordFinding's identity uses, excluding kind). Def->use fact lookup keys
on the source-independent (binding, def-point) portion. Same-source
multi-path flows still share one state so their exclusion sets intersect
(the raw arm soundly wins); termination holds (finite keys, monotone
shrink, no cross-source ping-pong). Restores the KTD6 identity contract.

* fix(mcp): route dotted symbol names in explain to symbol resolution (#2083 review)

The fileish classifier matched any dotted name (UserController.create)
as a file via its extension-like suffix, so symbol resolution never ran
and the tool returned a silent empty file-anchored result. Tighten the
classifier to require a path separator or a real source extension (derived
from the resolver's EXTENSIONS list, multi-language), so dotted/bare names
route to resolveSymbolCandidates (found / ambiguous / not-found).

* fix(mcp): gate explain no-taint-layer note on taintModelVersion (#2083 review)

An M1/M2-era --pdg index has meta.pdg defined (BasicBlock/REACHING_DEF
recorded) but no taintModelVersion and zero TAINTED rows. The probe keyed
on generic meta.pdg presence, so explain returned the generic empty note
instead of the actionable 'no taint layer — run analyze' hint. Gate on
meta.pdg?.taintModelVersion (the field M3 stamps) so an M2-era index gets
the layer hint; a taint-stamped index with no findings still gets the
generic note.

* fix(taint): sequence-expression value flows only the final operand (#2083 review)

A comma expression in value position (exec((log(x), 'safe'))) default-
descended, fanning every operand's occurrences into the enclosing sink
argument — over-tainting exec's arg 0 with x. Add an explicit walkValue
case that records earlier operands' uses with occurrence fan-out suppressed
(new FactAccumulator.suppressOccurrences) and routes only the last operand
through the value path. Sites-layer only; defs/uses/mayDefs byte-identical
(cfg + reaching-defs snapshots unchanged).

* perf(taint): FIFO head-cursor worklist + dedup before chainHops (#2083 review)

Replace queue.shift() (O(N) dequeue) with a strict-FIFO head cursor plus
order-preserving prefix reclamation; FIFO is load-bearing because chainHops
reads the live taints map whose parent/source/viaCall are rewritten
order-sensitively on monotone shrink, so hop determinism is dequeue-order
contingent. Extract findingKey() and dedup-check before chainHops in the
justify branch — already-recorded identities discard their hop chain
(first write wins), so the ancestry walk was pure waste. The else kill
branch is untouched. Findings + hops byte-identical (snapshot unchanged).

* perf(taint): O(1) member-read dedup via composite-key set (#2083 review)

addMemberRead rescanned the whole per-statement sites array per call to
dedup by (object, property, parent) — O(n^2) on member-read-dense
statements. Track a composite-key Set alongside sites for O(1) dedup.
(The require-literal join is already O(sites) with a no-op body on
non-require sites, so no early-exit is needed there.) Behavior identical:
harvest + model-match + taint snapshots unchanged.

* refactor(taint): drop test-only export; source taint caps via emit.ts (#2083 review)

Remove the sanitizerNeutralizes export (its only consumers were two test
assertions — inlined to entry.neutralizes membership). Re-export the
DEFAULT_PDG_MAX_TAINT_* caps from emit.ts and point run.ts at emit.ts, so
the pipeline's taint dependency surface is the single orchestration module
rather than reaching into propagate.ts.

* test(taint): extract the shared TS CFG/taint test harness (#2083 review)

The parse/collectFunctions/cfgOf/cfgsOf/importsFor harness was copied
byte-for-byte across four suites (harvest, model-match, propagate,
taint-emit). Promote it to test/helpers/ts-cfg-harness.ts and import it.
site-safety/reaching-defs carry a structurally different inlined builder
and are left as-is. Pure extraction, no assertion changes.

* test(mcp): harden explain limit-rejection battery (#2083 review)

Add NaN, Infinity, -Infinity, and a numeric string to the out-of-bounds
limit cases — a regression fence over the interpolated LIMIT, confirming
the Number.isInteger guard rejects every non-integer/non-finite/string
input before it reaches the query.
2026-06-12 07:35:09 +01:00