M2compiler-V3/docs/summary_step1.2.md

V3 step 1.2 — dynamic symbol storage (done 2026-09-19)

Follow-up to step 1.1 (scope tree + per-scope BST): the fixed-size pools are gone, replaced by Storage-allocated linked structures. SymTab.def unchanged apart from dropping the now-meaningless MaxSyms; M2.atg untouched; suite stays 6/6.

What changed (compiler/src/SymTab.mod only)

• Symbols: heap nodes (SymPtr, ALLOCATE + TSIZE) linked as a BST per scope instead of nodes[0..255]. No capacity limit; Enter fails only on duplicates.
• Scopes: heap nodes (ScopePtr) forming the scope tree, plus a creation-order link chain so PrintTable still dumps every scope (in-order per scope, alphabetical).
• Record fields: heap list (FieldPtr, filtered by owner) instead of fields[0..511].
• Kept bounded on purpose: pend[]/pendF[] (transient, per single declaration, max 64) and type descriptors (tform[]/tref[] — TypeIndex is an INTEGER woven through the grammar, so descriptors stay indexed for now).
• Nothing is ever freed: one compilation per process, the whole table is discarded at the next Init. DEALLOCATE intentionally unused (single-pass compiler, no steady-state growth).

Verification

Rebuilt clean (LL(1)-clean, no gm2 warnings introduced), 6/6 green: insert/find/dup-detection all exercised (t_bad_dup → 200, t_bad_undecl → 201, 3 run tests byte-identical .ssa — the backend is untouched).

Note for step 7 (syslib port)

FROM Storage IMPORT ALLOCATE is now the only gm2-hosted import in SymTab (plus SYSTEM.TSIZE, directly lowered later). The port swaps it for the self-hosted Storage without touching the tree logic — one reason the pool removal happened before the port.