`genProcBody` is handed `BNode(bodyBuf.rootCursor)` under `-d:newIcBackend`, so
`expr` and the ~160 procs under it read the routine body through a cursor rather
than a tree. This had to land as one change: `expr` dispatches to all of them, so
they move together or the dispatch converts at every node.
The evidence that it works is not that it compiles. Cursor-driven and
`PNode`-driven builds emit BYTE-IDENTICAL `.c` (50/50 on an 89k-line target,
12/12 on the grind target), the built program runs and prints the right thing,
and — the part that makes the first number mean something — sabotaging
`bnode.intVal` changes all 12 files. The generator is genuinely reading through
the cursor, not quietly falling back.
Four kinds of site could not simply take `AnyNode`, and each is marked where it
sits rather than left for the next person to rediscover:
* THE GENERATOR REWRITES. `mAppendSeqElem`, `mNewSeq`, `genSetLengthSeq`,
`genWasMoved` and `genArrToSeq` replace a child or a type IN PLACE, and
`genEnumToStr`/`mAsgn`/`spawn` build fresh trees. Those run on `origin(n)` —
the very node the buffer was encoded from — so the mutation lands exactly
where it always did. Where the mutation is then READ (`genArrToSeq` retypes a
bracket, `genArg` replaces a `var` param's type), generation continues on the
origin too, because the buffer does not see the write and a cursor would keep
reading the slot as encoded.
* NILABLE NODES stay `PNode`: a cursor has no standalone nil. That is the
assignment DESTINATION throughout the call family (`genCall` passes nil), the
`check` of an object-constructor field, `exvar`, `stepNode`, the `fin` of a
try statement.
* `PNode`-KEYED TABLES AND ANALYSES take `origin`: `dataCache`, `isPartOf`,
`lhsDoesAlias`, `potentialAlias`, the type-record walkers.
* SHARED PREDICATES in `ast.nim` cannot see `BNode`, so `skipHiddenAddr`,
`isInfixAs` and `getStr` join `canRaise`/`getInt` as templates instantiated
for both. `skipPragmaExpr` is a deliberate exception: it sits above the point
in `ast.nim` where `firstSon` for a `PNode` exists, so `bnode` carries a
one-line spelling with a pointer back.
Two Nim details worth recording. Repeated occurrences of a type class in one
signature share ONE implicit generic, so any proc whose two node parameters can
differ in representation needs explicit params — `genSingleVar`,
`genFieldObjConstr`, `callGlobalVarCppCtor`. And a `{.dirty.}` template inside a
generic resolves its identifiers at instantiation, so `genClosureCall`'s local
`rawProc` had to be bound before the template that uses it or it lost to the
module-level proc of the same name.
Verified: grind clean (1431 bodies, 260_431 nodes, 0 disagreements, origins
exact); the default path is byte-identical to HEAD; all four build
configurations compile.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XEF7FJvUkGKvG9LSGuEaNR
709fd00861