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summary_selfcompile-image.md

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História Raw

Nested modules + full compiler source set compiles; self image links

Tag v3-selfcompile-image. Main suite 111/111.

Landed

  • Nested modules (Wirth-style local MODULE … EXPORT …) — the driver's ListHandler now lowers: declarations use the enclosing QBE module prefix, a BEGIN body becomes an init function that main calls, and the EXPORT list is hoisted into the enclosing scope via SymTab.ExportUp (called before PopScope). Test t_nested (exit 42) exercises export + init + exported var/proc use.
  • HALT builtin (QbeGen.HaltQ, HaltStat): call $exit(w 1) + hlt.
  • Strings.Delete / Strings.Append added (the driver needs them for file names). Delete is correct; Append works only while the descriptor count has not been shrunk (see string-model note).
  • 1-char string literal to a VAR ARRAY OF CHAR formal (Strings.Append(".", …)): synthesizes a 1-char descriptor and passes its address.

Bugs found and fixed on the way

  1. Nested anonymous arrays clobbered the shared bound buffer. ARRAY [0..3] OF ARRAY [0..7] OF CHAR emitted the inner count for the outer level (8 instead of 4): the inner ArrayType reset the shared blo/bhi/nBounds before the outer NestArray ran. Fixed by snapshotting the bounds (new BoundCount/BoundLo/BoundHi) after ], before parsing the element type, then nesting from the snapshot. This also fixed QbeGen's own nestBufs (was 65536 entries).
  2. sessBuf too small / FileIO.WriteString misbehaves >~2 MB. The compiler's own image text exceeds 1 MB. Enlarged sessBuf to 4 MiB and flush exactly sessUsed bytes with a manual byte loop (host FileIO.WriteString segfaults on multi-MB buffers).
  3. strNams/strTexts capacity — the compiler image has >256 string literals; raised to 4096 (dropped literals previously left undefined $str256 references).

Milestone

The entire compiler source set now compiles under V3 (generated without -m, so M2P has real FORWARDs):

SymTab QbeGen M2S M2P M2 (driver)  →  gen_ssa/M2.ssa   (1.31 MB, complete image)
qbe  gen_ssa/M2.ssa                →  ok
cc   …shim.c -lm                   →  /tmp/M2self      (7.9 MB)

M2.ssa is self-contained (461 exported functions: all modules inlined, as V3's model does for a program module).

Next: self-compiled compiler crashes at startup

/tmp/M2self tests/t_constfold.mod → SIGSEGV in SymTab.Init:

Assign_189  <-  RawEnter  <-  Enter  <-  Predef  <-  Init  <-  SymTab_init

i.e. an early ALLOCATE/field-copy in symbol entry. Likely a V3 codegen/layout issue exposed by the compiler's own code (or the string model). This plus the Strings.Append model are the next tasks, then cross-stage FileIO + bootstrap/fixpoint.sh.

Files

compiler/src/{M2.atg,SymTab.def,SymTab.mod,QbeGen.def,QbeGen.mod}, compiler/tests/t_nested.mod, compiler/run_tests.sh, stdlib/strings.def, stdlib/strings.mod.