7.2 KiB
Private carried-baseline phase-check implementation
2026-09-25. Based on 18073a6f2eabce83fc83997f094e331eec835a16; implements the limited prerequisite selected in harness/analysis-carried-phase-contract-20260925.md (parent evidence commit a2c781773454ee932a9e292e6dc93f551f9f86c5). Source and tests are authored; compilation/runtime acceptance belong to parent gates and are not claimed here.
mixed/carried.rs introduces an opaque non-Clone input backed by either a fixed borrowed bundle with captured policy or a borrowed allocation-owning RetainedSnapshot. Every new constructor is cfg(test). The retained fixture owns the actual complete SourceBundle and computes exactly F map slots, zero lower occurrence slots and all source/key/entry UTF-8 bytes. The parser cannot substitute a different bundle at invocation. There is no production emitter/old-owner transition, accepted-output result, public source8 activation or editing authority.
The shared parser implementation has explicit legacy versus carried mode. Existing entry functions choose legacy and preserve their separate metadata checkpoints. Carried mode checks C initially, C+file metadata before traversal, C+U+M before every position projection and at complete syntax return, even when C is zero. Checks use existing logical Slots arithmetic and inherited ceilings; they are not additional retained reservations. A narrow read-only Budget policy getter preserves all Limits values. Every snapshot still has one fresh Budget and normal independent Usage/Exact work, with exact caller ProjectLimits.
ParsedMixedSyntax retains the guard. Consumed resolution seeds its Ledger from that guard once, then runs the existing syntax accounting and subsequent reservation/release sequence unchanged. Successful ownership naturally retains the guard through syntax inside resolved/indexed owners. A cfg(test) immutable phase_state observer exposes syntax/Slots for sibling tests; it exposes no mutation or production constructor.
Temporal scope is deliberately limited: current-unit parsing and syntax string decoding/copying can precede aggregate phase refusal, and retained syntax text is counted during resolution. Existing grammar event checks remain before their declared allocations; this prerequisite does not add universal parser allocation admission. Model/serde/raw validator heap, allocator capacity/RSS and stack frames keep their established exclusions. Stronger before-growth obligations, output creation, whole actual-output equality and accepted edited-output ownership remain future requirements. This work neither closes nor waives them.
Twelve authored tests cover independent E/H bundle counts and whole Project oracles, real retained guard identity, exact new Usage, once-only resolver +C retention, parser 13/12 and 25/24 boundaries, resolver 17/16 and 29/28 entry peaks, 112/111 and 214/213 text peaks, canonical original diagnostic paths/spans, initial C/file checks, postdecode syntax text and ordinary position-key copy accounting, unchanged legacy versus explicit carried-zero timing, all captured Limits/ProjectLimits fields, real byte/token/reference/frame/Exact/model/file/depth/include policies, and OA/SA Unicode/CRLF compatibility through both index families. Nonzero occurrence and impossible arithmetic cases are explicitly labeled fault injection; the actual retained bundle owner has no occurrence storage.
E is 78 source bytes with C=(1,0,102), U 1 / M 11 and final (13,0,110). H is 132 source bytes with C=(3,0,180), U 3 / M 19 and final (25,0,212); its final comment contains actual é and is 6 UTF-8 bytes. These expectations come from the independent parent oracle, not application outputs. Syntax-only exact caps are not reported as full-resolve successes. Parser default resource spans remain 0..1; resolver restores 0..0 or the original header/include extent.
Zero carried mode intentionally refuses E cap 11 at preprojection, while legacy cap 11 still produces syntax and then refuses resolution at U+M 12. This distinction preserves the old API timing without numerically bypassing the new carried contract. Borrowed policy capture from a still-live fixture witness is test-only propagation evidence, not proof old auxiliary B was consumed or dropped.
No Cargo/build/test execution was performed by the implementation agent. Targeted rustfmt on owned files and raw-LF normalization are authoring checks only. Parent owns source review integration, exact-source commits, compiler/focused/full-suite gates and publication. Inherited full-suite failures and formatting issues are not addressed by this patch; parent gates will compare actual outcomes. The documented environment-sensitive upstream stack observation remains a limitation. Existing small-stack controls were not edited or waived.
Independent test-source review corrected two pre-execution fixture mistakes: use the accepted oa_property/sa_property keywords, and distinguish the parser include-edge error span 0..1 from the traversal include-depth span 0..23. These are source-review corrections, not recorded runtime failures.
Recorded regression and slim-guard candidate
Parent's d11b99bb focused run passed all 12 carried tests, but its full run aborted at the unchanged ordinary_index::tests::small_stack_success_and_late_header_failure_leave_no_partial_owner with STATUS_STACK_OVERFLOW. The predecessor 18073a6f full run had completed with 230 passing tests and 16 inherited failures, including that control. This is a failed current full gate, not an inherited-failure waiver or an accepted repair.
The exact-artifact LLDB trace reproduces the overflow during Windows heap allocation under formatting/Exact::parse_decimal, then exact_literal, syntax::binding, declarations::parse, State::parse_typed, Parser::unit, new parse_impl, parse_with_profile, parse, accepted/indexed helpers and the existing worker. The diagnostic child's killed exit is not a test pass. Parent measured individual prologues of parse_impl 11,144 bytes, parse_with_profile 312, accepted 1,752, indexed 1,704 and worker 7,752; these are not the complete active stack. Raw evidence remains in the parent gate records, including carried-debugger-d11b99b-1.log and carried-full-d11b99b-1.stack-frames.json.
The selected narrow candidate consumes CarriedInput before entering the shared parser. Exact captured policy transfers into Budget and syntax.limits; the retained CarriedGuard holds only Borrowed or Retained(&RetainedSnapshot). This removes the duplicate inline SnapshotPolicy payload from parsed/resolved/indexed/result carriers, while retained backing still borrows the actual allocation-owning bundle. Borrowed source identity remains bound through ParsedMixedSyntax.bundle. Explicit Some mode still distinguishes carried zero from legacy None, and all checks/reservations/Usage remain unchanged. No heap allocation or new logical storage was introduced. The parser wrapper remains uninlined and unchanged.
Only carried tests' guard-shape inspection and direct injected-arithmetic access follow the new internal guard type; all expected counts, limits, spans, outcomes and existing stack tests remain unchanged. The candidate is not claimed to establish a sole overflow cause or a successful repair before parent exact-source gates. All original failure evidence remains retained.