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+# Session save — 2026-09-28: V3 self-hosting FIXPOINT reached
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+
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+`master` — suite **111/111**, tree clean except the user's uncommitted
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+`compiler/toto.mod` edit.
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+
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+## Headline: the fixpoint
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+
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+`bootstrap/fixpoint.sh`:
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+
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+```
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+Stage 1: gm2 builds V3 (CR -m) -> m2s1
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+Stage 2: m2s1 compiles the whole compiler -> stage2.ssa (assembled -> m2s2)
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+Stage 3: m2s2 compiles the whole compiler -> stage3.ssa
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+cmp stage2.ssa stage3.ssa *** FIXPOINT OK (1,991,439 bytes) ***
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+```
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+
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+The V3 compiler now rebuilds itself to a **byte-identical image**.
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+Tags: `v3-fixpoint`, `v3-bootstrap`.
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+
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+## The last fix (`b6ae57b`)
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+
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+`QbeGen.InitHeap` allocated each nested element sub-array (`ARRAY … OF
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+ARRAY …` on the heap/stack) but never initialised its descriptor
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+header, so a local `ARRAY [0..15] OF Name` handed garbage to
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+`GetName` (scanner) when `names[i]` was passed as an `ARRAY OF CHAR`.
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+Now `InitHeap(eb, elem)` is called on each sub-array.
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+
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+## Arc completed
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+
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+From "sources compile and link" to the fixpoint — every step a real V3
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+runtime/ABI bug with a minimal repro: nested modules; inline record
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+array fields; the NUL-terminated string model; `p^` as a `VAR` actual;
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+de-eagered NIL guards; off-by-one string scans; short-circuit `AND`/`OR`;
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+nested-array heap initialisation.
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+
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+## Codebases / tags of interest
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+
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+- `v3-fixpoint` — `b6ae57b` (the fix + `docs/summary_fixpoint.md`).
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+- `v3-bootstrap` — `42cbe36` (`bootstrap/fixpoint.sh`).
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+- Earlier: `v3-short-circuit`, `v3-selfcompiles`, `v3-inline-array-fields`,
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+ `v3-nul-strings`, `v3-deref-var-actual`, `v3-selfcompile-image`, …
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+
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+## Remaining polish
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+
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+- Cross-stage `FileIO` selection is implicit (stage 1 uses the host
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+ `FileIO`; the compiled image embeds the self-hosted one). Make it
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+ explicit if desired.
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+- Optionally `M2make`-driven build; more stdlib; unicode (step 6 plan).
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+- The toolchain still needs gm2 only for Stage 1 (bootstrapping the
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+ seed binary); `fixpoint.sh` documents the stage-aware CR flag.
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+
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+## Resume
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+
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+```sh
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+cd .../m2compiler-V3
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+./bootstrap/fixpoint.sh # FIXPOINT OK: stage2.ssa == stage3.ssa
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+cd compiler && ./build.sh && ./run_tests.sh # 111/111
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+```
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