taint.request_params emits guards/fixedOrigin/originAnchors/quotedSanitizers/
fieldParameterSources, which taint.sc reads from per-request JSON in its BATCH
branch but does NOT declare on `@main def exec` and does NOT consume in its
single-request branch (it defaults them). The single-query path passed them as
`--param guards=...` (disposable) or named args (session), so joern errored
`Unknown arguments` and every cpg.run("taint", ...) failed -- a silent zero of
the shape AGENTS.md warns about. scan_region->taint_verdict->_usable_flows and
the pair-path verdict()/verdicts() were dead; the push/scan batch route was
unaffected (it carries the extras as JSON the script parses itself).
Fix: parse the script's `@main def exec(...)` signature once (_declared_exec_params
+ memoised _declared_params) and, in query(), filter params to the declared set
before building either route. Faithful, not lossy -- the single-request branch
could never use those 5 fields. No-op for config/dominance (their request_params
emit only declared params; verified). Only taint sheds the 5 extras.
Verified end-to-end on banks (patched backend in the replay image): single-query
path now runs; baseline 0 findings, annotated search 2 path/model_entailed
findings (prompt->write_text). Regression test asserts no undeclared param
reaches the command line and the query parses, with a fake runner (no Joern).
Co-Authored-By: Claude Opus 4.8 <[email protected]>
Same CPG, only the search changes. Baseline (shipped path spec) resolves 0
prompt->write_text flows on banks; injecting the two annotations an LLM steer
would supply (parameter_sources=True + write_text/read_text path sinks) makes the
engine resolve prompt -> path-join -> prompt_file.write_text(prompt.raw). First
measured instance of "#2 guided by #1" closing on an unseen target; fix needed
exactly the param-source + file-write-sink annotations.
Files the instrument bug the first MVP hit: single-query cpg.run("taint",
request_params(...)) is dead -- request_params emits 5 keys (guards/fixedOrigin/
originAnchors/quotedSanitizers/fieldParameterSources) absent from taint.sc's exec
signature; both single-query sub-routes reject them (silent None). Batch path
(run_batch->requestsFile JSON) unaffected; push/scan route uses batch.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
