ADR-0003 — Reach the compiler as a bounded subprocess

type: adr status: Accepted tags: [adr]

Context

Checking, formatting, linting, running, testing, and language-server answers all belong to the installed pudu. Re-implementing any of them would drift from the compiler the user runs.

Decision

Every compiler answer comes from running the installed pudu (PUDU_BIN, else the first pudu on PATH) with a deadline and an output cap. Language-server questions are one complete conversation per question — initialize, open, ask, shutdown, exit — written to pudu lsp at once, and the transcript is parsed afterwards. The standard library is the installed one: PUDU_LIB, else <prefix>/lib/pudu beside the executable, else a checkout's packages/pudu/v0.1/lib.

Consequences

• Answers match the compiler version the user has.
• A slow or hung compiler costs at most the deadline; its partial output is still reported.
• All of this sits behind [[seams/Toolchain]] so the protocol core is tested without processes.

Rejected

• A long-lived pudu lsp child: keeps per-document state across unrelated requests, which the stateless protocol forbids relying on, and needs restart logic.

Referenced by

[[decisions/_MOC]] · [[seams/Toolchain]] · [[decisions/ADR-0002-compiled-documentation]]