Fixes #20010 Avoid crash on missing TASTy class references#25908
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soronpo wants to merge 2 commits intoscala:mainfrom
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Fixes #20010 Avoid crash on missing TASTy class references#25908soronpo wants to merge 2 commits intoscala:mainfrom
soronpo wants to merge 2 commits intoscala:mainfrom
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When a transitive dependency is missing from the classpath, the TASTy reader for a TYPEREF can produce a TypeRef whose symbol cannot be resolved. Downstream code in `computeBaseData` then hits an internal `non-class parent` assertion and crashes the compiler. Replace such unresolvable `TypeRef`s with a stub class symbol (similar to what Scala2Unpickler does), so the user sees a `BadSymbolicReference` error on first use instead of a compiler crash. The substitution is limited to references whose prefix is a package or a module, where member lookup is deterministic, to avoid converting transient lookup failures into spurious stubs during incremental completion. Adds an sbt scripted regression test (`sbt-test/tasty-compat/i20010`) that mirrors the original minimisation: three modules, `a`/`b`/`c`, where compiling `c` must not crash when `a` is absent from its classpath. https://claude.ai/code/session_01MmjynkrPu387FLVh175djG
The previous TreeUnpickler-based fix substituted a stub class symbol for any unresolvable cross-file `TypeRef` whose prefix is a package or module. That regressed `sbt-test/source-dependencies/missing-annot`: when a class on the classpath references annotation classes that are no longer reachable, the stub now eagerly throws a `BadSymbolicReference` error - even though the original behaviour was to silently tolerate missing annotations. Move the fix to its narrowest possible scope: the `non-class parent` assertion in `ClassDenotation.computeBaseData`. When the assertion would fire because a parent's `TypeRef` could not be resolved (`p.typeSymbol == NoSymbol`), report a `BadSymbolicReference`-style error with the position of the class that failed to resolve and continue. Annotation processing and other paths that legitimately tolerate missing references are unaffected. `computeBaseData` can be invoked multiple times for the same class (e.g. once via `derivesFrom` from `Namer.checkedParentType`, then again via `isValueClass` from `Checking.checkWellFormed`), so a per-denotation `reportedMissingParents` set deduplicates the diagnostic. Also handle the `MatchError` that fires when `computeMemberNames` encounters the same non-class parent: silently skip after the missing reference has already been reported. https://claude.ai/code/session_01MmjynkrPu387FLVh175djG
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I'm just curious about the CI, but I will close this PR. It's gotten too large to be vibe-coded. |
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When a transitive dependency is missing from the classpath, the TASTy reader for a TYPEREF can produce a TypeRef whose symbol cannot be resolved. Downstream code in
computeBaseDatathen hits an internalnon-class parentassertion and crashes the compiler.Replace such unresolvable
TypeRefs with a stub class symbol (similar to what Scala2Unpickler does), so the user sees aBadSymbolicReferenceerror on first use instead of a compiler crash. The substitution is limited to references whose prefix is a package or a module, where member lookup is deterministic, to avoid converting transient lookup failures into spurious stubs during incremental completion.Adds an sbt scripted regression test (
sbt-test/tasty-compat/i20010) that mirrors the original minimisation: three modules,a/b/c, where compilingcmust not crash whenais absent from its classpath.Fixes #20010
How much have you relied on LLM-based tools in this contribution?
Extensively, but its a small fix.
How was the solution tested?
New automated tests (including the issue's reproducer, if applicable)