Checking the markers for the first time found five disagreements in areas that
are implemented. Four were the marker's fault:
- own/badarg pinned "self", but the rule being broken is that a returned
reference must derive from a parameter -- `self` has nothing to do with it.
- own/badbrmov pinned line 9, which is the closing brace; the second destroy is
on line 8.
- own/badloop pinned line 8, the destroy after the loop. The diagnostic is on
line 6, inside it, and line 6 is right: the second iteration moves the same
value again, so the loop body is where it is caught. Whoever wrote the marker
expected the error after the loop.
- optional/badcatch pinned line 14, the body of the catch block. The catch
expression on line 13 is what cannot fall through.
The fifth was the compiler's. own/badweak assigns a `&mut i32` to a `&i32` and
got "initializer type mismatch", which says nothing about why. Weakening an
exclusive borrow to a shared one is a specific rule and now says so, for
references and slices alike.
own/ is fully green: 50/50. Overall 133 -> 138 of 188. The six remaining marker
disagreements are all under units/ and generic/, where nothing is implemented
yet, so there is no diagnostic to compare against and no way to tell whether
the marker is right.
The milestone structure had stopped describing the compiler and started
shaping it: m7.c, check_m7.c, tests/m2..m9, and a checker and emitter that had
each grown past 2,500 lines because there was nowhere else to put anything.
Restart from the pipeline instead.
What is left is the front end -- lexer, parser, types, ownership, semantic
analysis -- and the fixtures that describe it. The C backend, the DOSBox-X
runner, the milestone registry and the batch build are removed. The driver now
stops after semantic analysis; a code generator attaches where emit_c did.
Fixtures move from milestone directories to what they check:
parse/ grammar own/ ownership and borrowing
types/ type rules optional/ optionals and error unions
format/ formatting, try units/ units and visibility
generic/ generics pending-backend/
pending-backend/ holds the three fixtures that can only be checked by running
a program -- that the bounds check traps, that --no-checks removes it, and that
drops and defers actually fire, verified through a fake allocator. Those are
not front-end tests and are not pretending to be; they come back first when
there is a code generator.
tests/run.py replaces the DOSBox-X harness. It builds the front end with the
pinned Watcom's Windows-hosted driver and runs every fixture in about two
seconds, and it does something the old runner structurally could not: it reads
the `// ERROR:line:text` marker each fixture carries and checks the diagnostic
against it. Those markers have been in the tree all along, unverified, because
DOS could not redirect the compiler's stderr and only the exit code was ever
compared.
133/188 pass. The 55 failures are not regressions -- they are what was already
true and invisible:
- units (27) and generic (23): `import`, `comptime` and generic declarations
parse and are then dropped on the floor. No pass looks at them. The old
registry did not list these fixtures at all, so nothing said so.
- five in own/, optional/ and generic/: a marker disagrees with the diagnostic
about the line or the wording. Each is either a wrong marker or a wrong
diagnostic and has to be read individually.
Everything removed is in git history.