Selfhosting

Definition

For this project, true selfhosting means the compiler is capable of compiling its own Semantic source into the next compiler executable.

The intended proof is:

Stage 1 compiler
    ↓ compiles
msplc-selfhost.se
    ↓
Stage 2 compiler
    ↓ compiles the same source
msplc-selfhost.se
    ↓
Stage 3 compiler

A strong bootstrap check compares Stage 2 and Stage 3 behavior/artifacts under a deterministic build contract.

What does not count

The following may be useful during bootstrap engineering, but they are not the final selfhosting proof:

embedding a previously compiled EXE into .se comments or data;
extracting/replaying a seed executable;
invoking Go/C/C++ as the hidden implementation of the Semantic compiler;
replacing unsupported semantics with silent stubs.

Bootstrap stages

flowchart TD S0[Bootstrap implementation] --> S1[Stage 1 MSPLC] SRC[Semantic compiler source] --> S1 S1 -->|compile SRC| S2[Stage 2 MSPLC] SRC --> S2 S2 -->|compile SRC| S3[Stage 3 MSPLC] S2 --> V{Behavior / deterministic artifact check} S3 --> V

Why object-first debugging helps

The compiler is too large to treat every failure as a monolithic “EXE build failed”. COFF staging gives a finer-grained milestone:

parse/index Semantic compiler modules;
lower individual compiler units;
emit valid object artifacts;
resolve cross-unit symbols;
link the compiler executable;
use that executable for the next bootstrap stage.

Current status

The project has moved beyond a seed-only demonstration: real compiler .se units are being lowered into native objects. Full Stage 2 → Stage 3 selfhosting is still a work in progress and should not be claimed until the same Semantic compiler source can produce the next compiler end-to-end.