# self-hosting

- [ ] milestone: Honey compiles its production compiler, then that compiler compiles itself again and builds/runs the example programs.

## current boundary

directory packages support file-local import namespaces and postfix declaration
selection through the interpreter and native backend. the richer types/control
flow used by the compiler remain unsupported. the driver retains frontend storage
and source provenance through `@source/compilation`, with compilation-wide AST node identities.
file commands retain single-file behavior; directory commands compile the
package's production files and load its dependencies in separate scopes.

## next milestone: scalar-function packages

compile and run a small multi-file directory package importing a second package
of scalar functions, through both the interpreter and native backend.
using the existing standard library is a later acceptance gate: even `std/mem`
needs records, pointers, generics and C calls.

- [x] retain source/package identity and source ownership across the compilation; keep one identifier pool and unambiguous declaration IDs.
- [x] load directory packages once per canonical path, with deterministic file discovery, package scopes and root-only entry selection. follow Bro's existing relative and project-root `@` import rules; diagnose cycles rather than recurse indefinitely.
- [x] finish postfix namespace selection and resolve file-local import aliases without injecting dependency names into the importing package; bare and aliased import declarations are already parsed for dependency discovery.
- [x] reuse ordinary scalar signature checking, function values and IR calls for selected declarations; namespaces have no runtime representation.
- [x] preserve originating filenames and spans in dependency diagnostics and native runtime traps; retain demand-driven diagnostic recovery.
- [ ] verify sibling source files, transitive/shared imports, same-spelled declarations in different packages, alias conflicts, missing packages/members, argument errors and dependency-file diagnostics. preserve existing single-file commands.

visibility follows Bro's public-by-default contract; unsupported visibility
attributes must be diagnosed, never ignored. this milestone does not include
general record fields, imported types, test discovery or FFI.

## subsequent dependency gates

- [ ] concrete data models: required integer widths/conversions, records/tuples and construction, fields, enums, distinct/alias types, unions and matching. examples: `source/lexer/token.hon`, `source/sema/resolve.hon`, `std/mem/mem.hon`.
- [ ] memory representation: source pointers/references, mutable and sentinel slices, optionals, layout/cast builtins and allocator-required libc calls. internal IR array addresses are not source pointers. examples: `std/mem/mem.hon`, `std/arraylist/arraylist.hon`.
- [ ] fallible results and cleanup: error-set composition, `try`/`catch`, `defer`/`errdefer`; infrastructure errors remain distinct from diagnostic traps. examples: `source/main.hon:41`, `source/sema/check/check.hon:117`.
- [ ] generic specialization and compile-time execution/reflection sufficient for existing `ArrayList`, hash maps, `enummap`, `meta` and `io.print`; include type/value parameters and compile-time generated storage.
- [ ] remaining source constructs: collection/index iteration, expression-valued control flow and `yield`, compound updates and multiline strings. examples: `source/parser/parse.hon`, `source/llvm/runtime.hon`.
- [ ] standard-library milestone: compile/run a multi-package program exercising existing allocation and IO, including error cleanup; no replacement miniature standard library.
- [ ] native driver integration: required C ABI declarations, `process.Init` startup arguments/IO, actual CLI exit statuses, file loading, temporary files and spawning Clang. Honey-generated programs currently accept only parameterless `main` and print its result; Bro's bootstrap startup support is not Honey backend support.
- [ ] self-hosting proof: bootstrap-built Honey builds the production compiler (excluding test-only imports); that executable rebuilds the compiler; the rebuilt compiler passes representative interpreter/native examples and CLI/error scenarios without Bro at runtime.

the gates may require interleaving (notably allocation, errors and generics).
extend checking, IR and native emission together; accepting syntax alone does
not complete a gate. additional targets, a package registry, a replacement
linker and interpreter execution of arbitrary FFI are not prerequisites.