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diff --git a/docs/chapter-backports.md b/docs/chapter-backports.md index a7d3cfca..6e6d1d5c 100644 --- a/docs/chapter-backports.md +++ b/docs/chapter-backports.md @@ -4,32 +4,14 @@ This file tracks pending backports and deferred work. Completed work and old validation results belong in Git history. Reusable implementation constraints live in the [AI notes](../skills/chapter25-codex-notes.md). -The [approved chapter split](chapter-split.md) owns the teaching sequence for -the current Chapters 24 and 25. Use descriptive chapter names while the count -changes. Cliff approved starting with the proposed SCCP and construction/escape -boundaries; revisit construction/escape after he can run both snapshots. -Library construction and optimizer tuning move to appendices. - -The first named snapshots are `chapter-sccp`, `chapter-interprocedural-sccp`, -`chapter-incomplete-types`, `chapter-construction`, `chapter-escape`, and -`chapter-modules`. -Local SCCP keeps unknown callers and the call result summaries from pessimistic -analysis; the next chapter discovers calls -and widens recursive arguments and returns. Numbered Chapters 24 and 25 remain -comparison baselines during extraction. - -The incomplete-type snapshot groups numeric modes, conversions, guards, -symbolic fields, and unbounded Load/Phi nodes. Construction now has hidden -initializer/allocator calls, local field values and Phis, exit Stores, and -explicit publication. Private memory carries fields between helpers. Escape -now discovers exposed aliases/functions through the Start/Stop cycle. Review -the construction/escape border as needed. Modules/lazy initialization now has a -runnable snapshot; separate compilation is next. Chained comparisons still need -their move to Chapter 23; allocator tuning and native library material still -need their appendices. -Root Make includes named snapshots in checks. Linear-history publication keeps -the numbered sequence until the complete replacement sequence is ready; switch -its ordering and index links when retiring the comparison baselines. +The [completed split](chapter-split.md) places local/interprocedural SCCP in +24a/24b, incomplete types in 25, construction in 26, escape in 27, and +modules/separate compilation in 28a/28b. The combined old 24/25 snapshots are +retired. Do not backport fixes into those retired copies; their replacements +already retain the constructor, alias, native-exposure and import fixes. + +Native library construction and tuning material live in [appendices](appendices/README.md). +Future incremental builds are specified in [incremental-builds.md](incremental-builds.md). ## Four README intentions to review @@ -60,7 +42,7 @@ may change the construction/escape boundary or later chapter splits. ### Privacy proposal for review Introduce enforced underscore privacy in **Modules and Lazy Class -Initialization** (`chapter-modules`). This is a visible language change: +Initialization** (`chapter28a`). This is a visible language change: earlier snapshots allow underscore field access; from Modules onward, access must obey the declaring class's boundary. The teaching outline already places privacy here, alongside class names, ownership, and the public interface. @@ -121,46 +103,41 @@ After approval, implement and test in Modules, update its English/Japanese READMEs with the explicit language boundary, and run the full module suite including bundled `sys` and native execution. Cover allowed same-class access, rejected cross-class access, private class lookup, and forward receiver types. -Port the rule and library adaptations to the numbered Chapter 25 comparison -snapshot, with import tests preserving the original source owner. Carry it -into the forthcoming separate-compilation chapter. Do not backport the new +Carry the rule and library adaptations into Chapter 28b, with import tests +preserving the original source owner. Do not backport the new language restriction into Chapters 10-24 or the named pre-module snapshots. -## Proven Chapter 25 follow-ups from the module extraction - -Three failures reproduce in the numbered Chapter 25 baseline. The fixes are in -`chapter-modules`, but have not been copied back into that comparison snapshot: - -- A private recursive callback passed to native code retains `base == 2` from - known calls instead of restoring its declared `i64` bound. See - `BoundaryTest.testNativeExposure`. Carry direct Call exposure to StopCU even - on nonreturning paths, and restore Start when a function already has known - callers. `Opto.linkStart` must test unknown callers, not `nIns() < 2`. -- The lazy-table example crashes in `StoreNode.useAlias` when a symbolic class - Store has an EscapeNode user from a later allocation. Like - `BulkMemPhiNode.outputAlias`, use the publication field's alias when the Store - is that Escape's public-memory input. See `BoundaryTest.testLazyTables` and - `chapter-modules/src/test/smp/lazy`. The numbered baseline throws `Untested`. -- Final constructor fields lose writes when their declaration value is constant: - `val x=1; new C={->x=1; x=2;};` still reads back 1. Keep constructor field - declarations broad enough for later values, build loop Phis for final fields, - and preserve the distinction from final local bindings. See - `FinalConstructionTest` in the named snapshots. Recheck serialized declarations - and imported constructors when carrying this to the numbered baseline. - -Disposable reproducer: `build/SplitProbe.java`, compiled against Chapter 25; -arguments `native` and `array` exercise these failures. Port with the baseline's -import tests enabled, since the module snapshot intentionally lacks imports. - -Constructor local SSA, deferred constructor parsing and converted private -summaries also need to survive the final separate-compilation extraction. -These carry the already-reviewed construction design forward; they are not -independent changes for pre-construction chapters. - ## Investigate next Establish an earlier-chapter failure before changing compiler behavior. +### Prefix update of an enclosing class field + +The following returns 11 instead of 21 in numbered Chapter 25, Modules, and +Separate Compilation: + +```simple +int calls=0; +val next_noInline={ -> ++calls; }; +return next_noInline()+10*next_noInline(); +``` + +The prefix path updates an enclosing parser slot instead of class memory. +Postfix `calls++; return calls;` works and is used in the new chapter example. +This is independent of importing IR. The stage audit also reproduced the +instance-method form in Chapter 23, where methods first appear: + +```simple +struct C { int x=0; val inc={ -> ++x; }; }; +var c=new C; +return c.inc()+10*c.inc(); +``` + +It returns 11 instead of 21 in Chapters 23 and 26. Prefix lookup bypasses the +ordinary field-access path. A fix should share name resolution with other +reads/updates while preserving constructor locals, and propagate from 23 +through 28b. No fix is included in the numbering change. + ### Constructor loop with break/continue: worklist assertion This fails in construction and in the unchanged escape compiler before the @@ -214,7 +191,7 @@ and a null type. Thus the observed temporary lack of callers does not trigger `link()` cleanup. Keep this candidate unconfirmed rather than backporting the Chapter 25 lookup change on textual differences alone. -## Deferred until the Chapter 25 split +## Future compiler work ### Deterministic inlining @@ -257,13 +234,31 @@ Serialization, global identity remapping, and imported escape summaries belong with separate compilation. Escape analysis now has its own earlier snapshot after construction; keep its boundary open to review. -## Work that stays in Chapter 25 +### Selective loading of library IR + +Reliable incremental rebuilding is separate future work; see the +[incremental build design](incremental-builds.md) for the stale-dependency +example, required input tracking, rebuild propagation, and validation plan. + +The Separate Compilation README review found that importing only `sys.io.p` +still loads all ten units in the bundled `sys.o`, including `aryu8`, `aryi64`, +`scan`, and `adt.bitset`. All remain loaded through TypeCheck. Loading only +needed library members is a desired improvement, not current behavior. + +Selection works between independent objects: a client of `Counters.o` leaves +an unrelated `Unused.o` unloaded. Once selected, an object's entire saved IR +is reconstructed, and `ParseAll.loadDeps` follows its recorded dependencies. +Splitting the object alone is insufficient while the root's reexports and +unused function bodies still pull in those dependencies. Design member-level +IR loading and dependency discovery together; preserve type identity, +initialization rules, and imported escape summaries. This is separate from +whether imported code is initialized or emitted in the client's object. + +## Modules and separate compilation -Class-cycle checking and CLInit runtime lowering also appear in the new -modules snapshot; they do not belong in the pre-module chapters. The baseline -[chapter README](../chapter25/README.md#lazy-class-initialization) explains the -implementation; future work lives in the -[roadmap](../chapter25/ROADMAP.md#class-initialization-and-compiler-follow-ups). +Class-cycle checking and CLInit runtime lowering belong in 28a/28b. The +[module README](../chapter28a/README.md) explains their semantics; remaining +argument, initialization and pointer plans live in the [roadmap](roadmap.md). Native code cannot receive classes; a native-startup/class-handoff policy is not planned. Current data pointers remain eight bytes. |