The legacy tagged-Value Interpreter is gone. Relocate the Value result-DTO
+ decodeVariantElements into a new comptime_value.zig (the VM<->host
materialization boundary); repoint comptime_vm/emit_llvm/ir-barrel Value to
it and BuildConfig to compiler_hooks; delete the dead valueToReg bridge;
slim compiler_lib.zig to just the name registry (BoundFn{sx_name} + bound_fns
+ findFn — weldedCompilerFn only validates names); simplify printInterpBailDiag
to comptime_vm.last_bail_reason; drop the unused interp_mod import in lower.zig.
rm src/ir/interp.zig + interp.test.zig.
Value is relocated (not eliminated): it survives only as the slim result DTO
at the VM->valueToLLVMConst boundary; the execution-time marshaling the VM
pivot targeted is gone. Drop dead Value.asString/reflectTypeId.
706/0 corpus + 476/476 unit.
The compiler_call op + #compiler hook mechanism was fully superseded by
abi(.compiler) VM-native dispatch (P5.5) — no sx code emits it anymore.
Remove: the compiler_call op variant + CompilerCall struct (inst.zig); the
Builder.compilerCall emitter (module.zig); the two dead producer blocks in
lower/call.zig (compiler_expr-bodied free fns + methods); every consumer
switch arm (emit_llvm, ops.emitCompilerCall, print, interp dispatch); the
interp.hooks field + init/deinit. Strip compiler_hooks.zig down to the still-
live BuildConfig / BuildHooks / AssetDir (delete HookError/HookFn/Registry/
registerDefaults + all hookXxx, and the now-unused interp/Value imports).
Test refs that used compiler_call as a sample unported op now use vec_splat.
501/501 unit + 706/0 corpus.
`BuildOptions :: struct #compiler { ...35 methods... }` becomes
`BuildOptions :: struct { }` (an opaque null-sentinel handle) plus 35 free
`ufcs (self: BuildOptions, …) abi(.compiler)` decls in build.sx, each serviced
by a new `comptime_vm.callBuildOptionFn` arm (off `callCompilerFn`). No legacy
`compiler_lib` handler: the names are registered in `bound_fns` with a single
bailing stub only so `weldedCompilerFn` accepts them.
- String lifetime: setters dupe the arg into the persistent `Vm.gpa` (the
Compilation allocator, threaded into both `tryEval` and `runBuildCallback` —
not the per-eval VM arena) and write/append to the threaded `BuildConfig`.
Getters read the field/slice or compute the target predicate from the triple.
- Dispatch routing (Option B): a `#run`/const-init entry that directly calls a
compiler-domain/welded fn (`emit_llvm.entryNeedsVm`) runs on the VM with no
legacy fallback regardless of the `-Dcomptime-flat` gate, so gate-OFF stays
green without a legacy BuildOptions handler (P5.7 retires the legacy interp).
- Mark the 5 `platform/bundle.sx` getter-calling helpers `abi(.compiler)` (they
are comptime-only bundler code; otherwise their now-welded getter calls trip
the runtime-call gate).
- 37 `.ir` snapshots regenerated (std transitively imports build.sx → string-
pool/type-table indices shift); verified `.ir`-only, zero behavior-stream diffs.
BuildOptions `compiler_call` strict bails gone (1609/1614/1615 strict-clean);
1616 now bails on a separate, pre-existing unported bitwise/shift VM gap (`shr`),
to port first in P5.6. 703/0 both gates.
Also sweep the outdated "flat memory" terminology to "comptime/byte-addressable"
across comptime_vm + the plan/checkpoint/CLAUDE docs: the comptime VM is
arena-backed, byte-addressable memory where `Addr` is a real host pointer, not a
flat contiguous address space (flag names `-Dcomptime-flat`/`SX_COMPTIME_FLAT` kept).
Lands the full VM/compiler-API arc on branch reify (701/0 both gates):
- abi(.compiler) ABI replaces abi(.zig) extern compiler + the fake
#library "compiler"; bodiless decl = compiler-API surface, bodied =
user compiler-domain fn (lowered for VM eval, emit-skipped).
- out is a plain sx fn (libc write) — the out builtin deleted; the VM
handles it via host-FFI. trace_resolve + interp_print_frames ported.
- 4B VM-native diagnostics: 1179/1180 render proper comptime type
construction failed: under strict.
- S5a: build_options/set_post_link_callback on abi(.compiler) with
BuildConfig threaded into the VM (green intermediate).
- 0522 fixed (describe(args: []Type)); regression 0638.
Strict deletion-gate down to 4 compiler_call bails (1609/1614/1615/1616)
+ 1654 (legitimate unresolvable-symbol diagnostic).
Replace the growable ArrayList(u8) flat buffer (reallocs/MOVES on growth) with a
std.heap.ArenaAllocator. Each allocBytes is a separate arena allocation that never
moves and is freed wholesale on deinit -- no per-object free, no cap, no fixed
buffer. Addr is now the allocation's ABSOLUTE host pointer (@intFromPtr), not an
offset, so a flat-memory pointer and an FFI-returned host pointer are the same kind
of value -- the FFI bridge (4D.1) passes them to/from libc with zero translation and
no per-call pinning (the moving-buffer hazard is gone by construction).
readWord/writeWord/bytes deref the absolute pointer with a null-check bail (the
malformed-IR / null-deref safety contract). Dropped the offset-based upper-bounds
check (can't bound an absolute pointer; Frame.bad_ref still catches the dominant
malformed-IR vector) and the test-only mark/reset (arena has no reset-to-mark; the
VM never used them outside tests).
697/0 both gates + all unit tests (rewrote the two Machine tests). Pure refactor, no
comptime behavior change.
Ported the Any-boxing conversion pair:
- box_any: alloc the 16-byte { type_tag@0, value@8 } box, tag = source TypeId
index (matches the legacy comptime interp; runtime anyTag also normalizes
arbitrary-width ints). Value slot holds a word source's scalar bytes (via
writeField(source_type) so f32 round-trips) or an aggregate source's
flat-memory ADDR (the runtime pointer-in-value-slot shape).
- unbox_any: read the value slot back (word -> readField; aggregate -> the
stored ADDR).
Required promoting .any to a first-class flat-memory aggregate (was
kindOf -> .unsupported): kindOf(.any) = .aggregate (16B, by-address) and
fieldOffset special-cases .any to the {@0, @8} layout (shared with
string/slice). Without the latter a struct_get on an Any panicked
(union field 'struct' while 'any' is active) -- caught + fixed, no crash.
Updated two unit tests that used unbox_any as the "unported op" example ->
compiler_call; added a box->unbox round-trip test. 697/0 both gates + all
unit tests. The 6 box_any examples no longer bail at box_any (output matches
legacy) but fall back further at switch_br/type_name/out (later 4A steps).
The metatype type-construction builtins now run natively on the flat-memory
VM, so the construction examples run HANDLED end-to-end (no call_builtin
fallback to the legacy interp).
- Tagged-union enum_init WITH payload: allocate zeroed, write the tag at
offset 0, copy the payload at tag_size ({ header, [N x i8] } layout).
- New .call_builtin exec arm -> callBuiltinVm (VM-native mirror of the legacy
execBuiltinInner): declare(name) mints an empty forward nominal slot (shared
declareNominal, also used by declare_type); define(handle, info) reads the
TypeInfo tagged-union VALUE from flat memory and mints via defineFromInfo,
a faithful port of legacy defineEnum/defineStruct/defineTuple (all-void enum
-> real .enum per issue 0142, dup-name rejection, updatePreservingKey vs
replaceKeyedInfo). Unmodeled builtins bail -> legacy fallback (dual-path).
- Refactored the []{name,ty} decode out of registerTypeVm into a shared
decodeMemberSlice (+ decodeTypeSlice for bare-Type tuple elements).
- Correctness guard: enum_init/define assume a tag-headed layout, wrong for a
backing_type tagged union (laid out as the backing struct) — both now bail
loudly on backing_type != null rather than silent-clobber.
Examples 0614/0620/0621/0624/0632 run fully HANDLED on the VM; 0622/0623 run
define HANDLED then fall back at the still-unported type_info. VM output
byte-matches legacy for all 7. 697/0 both gates + all unit tests (added:
tagged-union enum_init payload layout).
The VM can now evaluate a comptime type-fn that allocates at lowering time (the
0141 family) — the legacy interp cannot. Four changes:
- runComptimeTypeFunc (lower/comptime.zig): force the CAllocator->Allocator thunks
to exist (getOrCreateThunks, idempotent, guarded) BEFORE eval. A type-fn const
runs at scanDecls (Pass 1), before Pass 1c builds the default-context global +
thunks, so the comptime allocator was otherwise null.
- materializeDefaultContext: build a REAL context at lowering time when the global
is absent — find the two thunks by name and lay their func-refs into the inline
Allocator value at the head of Context, so context.allocator.alloc_bytes
dispatches call_indirect -> thunk -> native VM malloc.
- aggType: deref a pointer base_type (the List write path emits struct_gep with
base_type = *Struct; fieldOffset panicked on the pointer — now derefs, no panic).
- subslice: handle a [*]T many-pointer / *T base (a List's items field — the base
IS the data pointer).
Verified end-to-end (manual probe): a compiler-API type-fn building its []Member in
a List(Member) runs HANDLED on the VM and mints (green=7) — the 0141 List-growth
pattern. Can't be a corpus test yet (gate-OFF/legacy can't allocate at lowering
time — the dual-path bind), so locked in via VM unit tests (many-pointer subslice;
struct_gep with a pointer base_type). 697/0 both gates + all unit tests.
kindOf(.type_value) -> .word; new const_type exec arm -> word = TypeId.index();
regToValue maps a .type_value word back to a .type_tag Value at the legacy
boundary. The VM now runs comptime evals involving Type values instead of
bailing.
This reached a latent VM panic: struct_init assumed a .@"struct" result type and
union-access-panicked on an array literal (EnumVariant.[...]). It is the generic
aggregate-literal op, so it now dispatches on the result kind (struct/array/
tuple) and bails loudly on anything else — never panics (CLAUDE.md no-panic).
697/0 both gates (make_enum type-fns run further on the VM, then bail cleanly at
the define call_builtin -> legacy mints; no mutation before bail). VM unit test
added (const_type -> word -> regToValue -> .type_tag).
Prerequisite for wiring the VM at the lowering-time comptime site
(runComptimeTypeFunc), where IR can be malformed (an unresolved name lowers to a
dangling / Ref.none operand — the 0737 crash). Close the remaining panic vectors
so the VM bails (-> legacy fallback) instead of aborting:
- Vm.refTy(ref_types, r): a bounds-checked accessor replacing every raw
ref_types[ref.index()] in exec — the type-side companion to Frame.get's
bad_ref value-side guard.
- aggType is now a bailing method (Error!TypeId) routed through refTy.
- the block-dispatch loop bounds-checks the branch target before indexing
func.blocks.items (a malformed br target). global_get was already guarded.
No behavior change: gate OFF and -Dcomptime-flat both 697/0. Unit test added
(a cmp_lt with a Ref.none operand bails, not panics).
The last two read-only readers the metatype's type_info(T) needs, each backed by
a TypeTable query both the legacy handler and the VM call (no drift):
type_kind(t: TypeId) -> i64 (kindCode; stable discriminant, total — never bails)
type_field_value(t: TypeId, idx) -> i64 (memberValue; enum explicit value or ordinal)
kindCode codes (compiler-owned, stable): 0 other / 1 struct / 2 enum /
3 tagged_union / 4 tuple / 5 union / 6 array / 7 vector / 8 error_set.
With these, the READ side is complete: find_type + type_kind + type_field_count +
type_field_{name,type} + type_nominal_name + type_field_value cover everything
reflectTypeInfo reads — a comptime sx fn can fully reflect a struct/enum/tuple
into data with no #builtin.
Example 0630 reflects Color / WindowFlags(flags) / Point. VM unit test added.
Revised forward direction: the write side will be ONE register_type(info) fn that
branches on the kind in the compiler (subsuming define's per-kind dispatch), not a
per-kind register_struct.
Parity 691/691 (gate OFF and -Dcomptime-flat).
Three more read-only compiler-API readers on the TypeId-handle shape, each backed
by a new TypeTable query that both the legacy handler and the VM call (no drift):
type_nominal_name(t: TypeId) -> StringId (nominalName; loud-bail for unnamed types)
type_field_name(t: TypeId, idx: i64) -> StringId (memberName)
type_field_type(t: TypeId, idx: i64) -> TypeId (memberType)
All loud-bail on out-of-range idx / no-member — no silent default. First multi-arg
compiler fns (callCompilerFn now reads arg 1 = idx); added Vm.argHandle/argTypeId
range-checked arg readers and moved find_type/type_field_count onto them. Names use
the type_* family to avoid colliding with the std metatype builtins (field_name /
type_name in core.sx); the new TypeTable.nominalName is distinct from the existing
typeName(id) display-string renderer.
Example 0629 reflects Pair { lo: Point; hi: Point } — each field name + the nominal
name of a field's type, #run-folded, VM-HANDLED natively. VM unit test added.
Parity 690/690 (gate OFF and -Dcomptime-flat).
First read-only compiler-API reflection readers, bound the same way as the
intern/text_of seed (compiler_lib.bound_fns + Vm.callCompilerFn, native on flat
memory, no marshaling). A type handle is a plain u32 TypeId (like StringId), so
both stay clean scalar host-calls:
find_type(name: StringId) -> TypeId (TypeTable.findByName; unresolved/0 if absent)
type_field_count(t: TypeId) -> i64 (new TypeTable.memberCount; loud-bail, no silent 0)
memberCount is the single source both the legacy handler and the VM read, so the
two paths can't drift. find_type returns a non-optional TypeId using the
unresolved(0) sentinel for not-found rather than ?Type — a Type value is
.any-typed (which the flat-memory VM does not represent) and an optional can't
cross the legacy<->VM eval boundary; unresolved is the project-blessed "no type"
marker.
Example 0628 chains intern -> find_type -> type_field_count (+ a not-found
lookup), folded at #run, VM-HANDLED natively. VM unit test added.
Parity 689/689 (gate OFF and -Dcomptime-flat).
Phase 1.final of the flat-memory comptime VM — wire the host through it,
reach corpus parity, and gate it behind a build flag — plus the first
Phase 3 (compiler-API) step. Default OFF; legacy interpreter unchanged.
Host wiring + hardening:
- Machine accessors return error.OutOfBounds (no debug panic) on bad
addresses; Frame.get/set bounds-check and bail (no panic) on a malformed
operand ref (e.g. a ret Ref.none from an unresolved name).
- tryEval routed at both comptime call sites in emit_llvm — the const-init
fold and the #run side-effect path — with per-eval legacy fallback;
yields .void_val for void/noreturn entries. Both sites sx_trace_clear()
before the legacy fallback so a partial VM run that pushed trace frames
doesn't double-push on re-run.
VM coverage (all corpus const-inits except the inline-asm global):
- Implicit context materialized from the __sx_default_context global; the
full allocator protocol runs on the VM (context.allocator.alloc ->
call_indirect -> CAllocator thunk -> libc_malloc -> native flat malloc).
- Native libc memory builtins (malloc/calloc/free/memcpy/memmove/memset)
on flat memory; f32 stored/loaded as the 4-byte single; signed sub-64-bit
loads sign-extended; global_get (lazy + memoized); func_ref/call_indirect
(func-ref encoded fid+1, 0 reserved for null); string/slice fat-pointer
field access; is_comptime; the failable/error cluster (error_set tuples,
trace_frame + native sx_trace_push/clear -> raise/catch/or + return traces).
Build flag + Phase 3 seed:
- -Dcomptime-flat (build_opts module) OR SX_COMPTIME_FLAT env enables the VM;
zig build test -Dcomptime-flat runs the full corpus on the VM (688/0).
- intern/text_of serviced natively on flat memory via Vm.callCompilerFn
(compiler_welded boundary) — the seed the rest of the compiler-API grows on.
Parity 688/688 gate ON and OFF. Unit tests added throughout. The
lowering-time #insert wiring was explored and reverted (lowering-time IR can
be malformed; full malformed-IR hardening is a prerequisite, deferred).
Phase 1 of the flat-memory comptime VM (current/PLAN-COMPILER-VM.md),
built standalone + unit-tested with the legacy interpreter still live and
the corpus untouched (688 green).
src/ir/comptime_vm.zig:
- Machine: one linear byte memory (comptime stack+heap) with a bump/stack
allocator (mark/reset), scalar readWord/writeWord (1/2/4/8 LE) + byte
views; addr 0 reserved as null_addr. Frame: a Ref-indexed register file
(Reg = raw u64: immediate scalar bits OR an Addr). Target-aware layout
comes from the type table, so cross-compilation stays correct.
- Vm executor over the SAME SSA IR, mirroring the legacy interp's scalar
semantics (i64 wrapping/signed, f64). Ported: constants, arithmetic,
comparison, logical, conversions, control flow (br/cond_br/ret + block
params); structs (alloca/load/store/struct_init/get/gep at target
offsets); tuples; arrays (index_get/gep, length); slices+strings as
{ptr,len} fat pointers (const_string, data_ptr, subslice,
array_to_slice, str_eq/ne, index-through-slice); optionals (pointer and
{T,i1} shapes); payloadless enums; deref/addr_of; direct + recursive
call over the shared flat memory (depth-guarded). The value model: a
word for scalars/pointers, by-address for aggregates (a struct's value
IS its Addr). Any unported op bails loudly (error.Unsupported + detail).
- Reg<->Value boundary bridge (valueToReg / regToValue) + tryEval, the
hybrid-wiring entry point: run a comptime fn on the VM, return a legacy
Value or null to fall back. Transitional, for the legacy interop edge.
Registered in the ir.zig barrel.
