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.
`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Also sweep the outdated "flat memory" terminology to "comptime/byte-addressable"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).
on_build is now the sole post-build callback mechanism. Migrated the 9 callers
(0602/0603/1611/1614/1615/1616 + the platform bundle_main) from
opts.set_post_link_callback(cb) to on_build(cb), giving each callback the
(opt: BuildOptions) param. Deleted set_post_link_callback from build.sx,
compiler_lib (bound_fns + handleSetPostLinkCallback), and the VM arm.
Reworked the P5 smoke tests for the new semantics: an on_build override REPLACES
the build (must emit+link or delegate), unlike the old post-link callback which
ran after the auto-link. 1662 (queries) + 1664 (override+List-grow) now delegate
to default_pipeline for the real build; deleted 1661/1663 (the primitives are now
exercised by every AOT build). bundle_main invoked with pass_options=true.
Benign 37-.ir churn (build.sx shrank). 703/0 both gates.
The compiler's post-IR role shrinks to: codegen -> invoke the build callback.
There is NO Zig auto-emit / auto-link anymore; emit + link are sx-called actions.
- emit_object() is now an ACTION (verify + emit via a host BuildHooks vtable),
returning the object path. New query primitives build_output/build_target/
build_frameworks/build_flags (data reads from the merged BuildConfig).
- library/modules/build.sx imports compiler.sx and defines default_pipeline:
emit_object -> gather c_object_paths -> link(objs, output, libs, fws, flags,
target). The std<->build import cycle is handled by the resolver.
- The compiler FORCE-LOWERS default_pipeline (well-known name) and AUTO-INVOKES
it post-codegen when no on_build/set_post_link_callback override was
registered (driver's final fallback: invokeByName default_pipeline).
- Prelude-less programs (e.g. asm tests) don't import build.sx, so the BUILD
path auto-imports modules/build.sx (idempotent if already transitive) so
default_pipeline is always available. JIT sx run is untouched (emits in-process).
- Removed the build cache short-circuits (incompatible with the always-run sx
driver; a future cache can live in default_pipeline).
Benign 37-.ir churn (build.sx grew); zero behavior changes (verified diff is
.ir-only). 705/0 both gates.
Per user design: on_build(build) is the build-callback registrar (a free fn),
generalizing set_post_link_callback — the callback is (opt: BuildOptions) ->
bool and the compiler invokes it post-codegen WITH the BuildOptions handle.
- VM: callCompilerFn 'on_build' arm + legacy handleOnBuild, both set
post_link_callback_fn + a new BuildConfig.post_link_takes_options flag.
- comptime_vm: runEntry refactored to runEntryArgs(extra) (implicit ctx +
explicit args); new public runBuildCallback(..., pass_options) passes the
opaque BuildOptions handle (one word) after the ctx. The fat-config
marshaling fear is moot — the handle is a single null-sentinel word.
- core.invokeByFuncId/invokeByName take pass_options (was an unused args
slice); main.zig passes comp.getPostLinkTakesOptions().
- build.sx: on_build decl (set_post_link_callback kept for now).
Smoke test examples/1664-platform-on-build-callback (AOT): #run on_build(build)
with build :: (opt: BuildOptions) -> bool; the callback is invoked with the
handle arg (runEntryArgs param-count match) and runs the primitives.
Benign .ir churn (37 snapshots: type table +1 for the on_build fn type +
global renumber; behavior identical). 705/0 both gates.
The one genuine action primitive: link(objects, output, libraries, frameworks,
flags, target) in library/modules/std/build.sx. Per the user decision to drop
fallibility from the build callback, link is plain VOID — a link failure bails
on the VM (hard build error), no -> ! / failable-tuple needed.
comptime_vm.zig can't depend on the driver (core/main/target), so link
dispatches through a new compiler_hooks.BuildHooks { ctx, link } vtable that
main.zig installs into BuildConfig.build_hooks before the post-link callback.
The driver side is main.LinkHooksCtx (unions explicit + CLI link flags, calls
target.link). New VM readers readStringList / readStringArg (inverse of
makeStringList) decode the List(string)/string args from flat memory.
Smoke test examples/1663-platform-build-pipeline-link (AOT): a post-link
callback re-links the build's own objects (c_object_paths + emit_object) into a
temp output via sx link — the relinked binary is a functional executable that
runs. Negative-probe verified (bad path -> ld fails -> ComptimeVmBail -> build
exit 1). The Zig driver still auto-links; removing that is P5.4.
704/0 both gates.
The compiler emits the sx object eagerly (the Zig driver, before the post-link
callback), so emit_object is a QUERY (not an action): it returns the path from
a new BuildConfig.object_path field main.zig forwards — no driver vtable. This
completes the build-pipeline QUERY primitives (emit_object / c_object_paths /
link_libraries); only link (the genuine action) remains for the vtable step.
Extended examples/1662 to also assert emit_object().len > 0. 703/0 both gates.
Two abi(.compiler) build-pipeline primitives the sx driver will pass to link:
- c_object_paths() -> List(string) (#import c companion objects)
- link_libraries() -> List(string) (#library names)
They live in a new stdlib home library/modules/std/build.sx and are serviced
by comptime_vm.callCompilerFn reading two new BuildConfig fields that main.zig
forwards before the post-link callback. New reusable VM helper makeStringList
builds a List(string) in flat memory from the call's result type offsets
(target-aware); invoke/callCompilerFn now thread ins.ty for that. Legacy
handlers bail loudly (VM-only by nature — post-link; List(string) isn't
faithfully buildable in the legacy Value model, 0141).
Smoke test examples/1662-platform-build-pipeline-queries (AOT + a 1-line C
#source → one object): a post-link callback verifies the VM-built list is
well-formed; build exit 0 only if so (negative-probe confirmed a real guard).
emit_object + link (the actions) deferred to P5.2b — they replace the Zig
driver's auto-emit/auto-link and need a host-installed callback vtable.
703/0 both gates.
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).
The mutating compiler-API, minting types LAZILY at lowering time (single pass,
the existing runComptimeTypeFunc path — so the write side is legacy-only; the
VM isn't wired at lowering time, and the read-side readers stay dual-path):
declare_type(name) -> Type forward nominal handle (≈ declare)
pointer_to(t) -> Type build *T references
register_type(handle, kind, members) ONE kind-branching fill (≈ unified define)
register_type branches on kind IN THE COMPILER (subsuming define's per-kind
dispatch); codes match type_kind: 1 struct, 2 actual .@"enum", 3 tagged_union,
4 tuple. Members are {name: string, ty: Type}. A non-generic `-> Type` builder is
now flagged is_comptime (decl.zig) so its dead body permits the welded calls.
Graph support: forward declare_type handles + pointer_to express a mutually-
recursive A<->B graph (*A, *B, B-by-value) before bodies are filled. register_type
is idempotent — re-filling a nominal slot (a minting module reached via two import
edges) re-mints identically rather than erroring (nominalIdent reads identity from
any nominal kind).
Fixes (issue 0142):
- A fully payloadless comptime-minted enum was minted as an all-void tagged_union,
whose IR size disagrees with its LLVM size -> verifySizes panic. Now mints a real
.@"enum" (register_type kind 2 AND the metatype defineEnum).
- Bare `EnumType.variant` qualified construction of a payloadless variant wasn't
supported (failed for hand-written enums too — the type name lowered to a Type
value). Added in lowerFieldAccess via isPayloadlessVariant; payload-carrying
variants keep their call form.
Examples: 0631 (graph + actual enum + reflection), 0632 (make_enum all-void),
0633/0634/0635 (namespaced / bare / multi-edge import of a minted type), 0187
(qualified variant construction). Unit tests added.
Parity 697/697 (gate OFF and -Dcomptime-flat).
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).
The byte-weld (sx structs whose layout was validated to mirror the
compiler's Zig records) plus the serialization/marshaling bridge was the
wrong direction: it bolted a parallel layout regime and hand-built
byte-copies onto a comptime value model that fundamentally isn't bytes.
Strip the struct-weld machinery:
- compiler_lib.zig loses the type registry (weldStruct / bound_types /
BoundType / FieldLayout / findType / SxField / LayoutMismatch /
validateStructLayout); it is now just the intern/text_of function
host-call bridge (kept as the Phase-3 compiler-call seed).
- nominal.zig loses validateWeldedStruct / weldedFieldOrderStr + the
sd.abi == .zig validation call.
- Remove the struct-weld unit tests and examples 0625/0627 (welded
structs) + 1183/1186 (weld-layout diagnostics).
- The #library / abi / extern syntax stays.
Record the new direction: a bytecode VM over flat, byte-addressable
memory so comptime values are native bytes (no weld/validation/marshal),
target-aware (preserves cross-compilation) and sandboxed. See
current/PLAN-COMPILER-VM.md (Phase 0 strip -> Phase 1 flat-memory value
model -> Phase 2 bytecode -> Phase 3 compiler-API on flat memory).
design/comptime-compiler-api.md gets a SUPERSEDED banner. Also drop the
"~500 lines / split the step" rule from CLAUDE.md.
Replace the explored byte-layout-override engine (offset-ordered LLVM structs /
weld plans / byte-blobs — all unnecessary) with a much simpler design: a welded
`struct abi(.zig) extern compiler { … }` is a bodied header declaring its fields
in the bound compiler type's MEMORY order. The compiler reflects the real Zig
type (field names via @typeInfo, offsets via @offsetOf, size via @sizeOf —
nothing hand-maintained) and validates the header matches, with loud diagnostics.
On pass it is an ordinary struct whose natural layout already equals the Zig
layout — no reorder, no padding, no index/remap tables, no special LLVM path — so
@ptrCast'ing it to the compiler's own type and dereferencing is byte-identical.
When types.zig shifts, the header stops matching and the developer gets a specific
message to fix it.
- compiler_lib.zig: weldStruct reflects field names and bakes bound_types fields
in ascending-offset (memory) order; deleted computeWeldPlan/WeldPlan/WeldElement.
- nominal.zig validateWeldedStruct: precise diagnostics — field-not-found,
wrong-field-order (+ expected memory order), type-layout (size) mismatch,
total-size mismatch.
- Examples: 0627 (StructInfo in memory order, byte-identical, usable),
1186 (source-order StructInfo -> wrong-field-order diagnostic); 1183 refreshed.
- Design doc + checkpoint updated.
Introduce the welded comptime `compiler` library (`#library "compiler"` +
`abi(.zig) extern compiler`), per design/comptime-compiler-api.md, and unify
`callconv(...)` into the new `abi(...)` annotation.
abi(...) replaces callconv(...):
- New ABI enum { default, c, zig, pure }; `abi(.c|.zig|.pure)` parses in the
postfix slot before extern/export (and standalone). `kw_callconv` -> `kw_abi`.
- Migrated 52 sx files, the call-convention-mismatch diagnostic, and docs
(readme/specs) from `callconv(.c)` to `abi(.c)`.
Phase 1 — welded compiler library (parse -> registry -> validation -> bridge):
- `abi(.zig) extern compiler` parses on fn decls (carries abi/extern_lib) and
struct decls (StructDecl.abi/extern_lib).
- `#library "compiler"` is the comptime-only internal surface — never dlopen'd.
- src/ir/compiler_lib.zig: the binding registry (the safety boundary). `Field`
welded to StructInfo.Field with layout baked from the real Zig type
(@offsetOf/@sizeOf); `findType`/`findFn`. Welded structs are layout-validated
at registration (field set + total size) as a header checked against the impl.
- Host-call bridge: a `fn abi(.zig) extern compiler` dispatches under the
comptime interp to its registered Zig handler (intern/text_of round-trip),
never dlsym. IR Function.compiler_welded; validated in declareFunction.
- Comptime-only enforcement: a runtime call to a welded fn is a clean
build-gating error (emitCall), not an undefined-symbol link failure.
Phase 2.1 — byte-layout weld foundation:
- Decision: full byte-layout weld (sx struct laid out byte-identically to the
bound Zig type). Registered StructInfo (first non-natural / Zig-reordered
layout). `computeWeldPlan` — pure offset-ordered element plan + padding +
sx-field->LLVM-element remap; unit-tested. Emit/interp wiring is the next
sub-step (2.2+, see current/CHECKPOINT-COMPILER-API.md).
Examples: 0625/0626 (welded struct + fn round-trip), 1183/1184/1185
(layout-mismatch, unexported-fn, runtime-call diagnostics).
