Do not narrow a typed value to Opaque on typeof "function" - #328
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`typeof f === "function"` (also "class", "interface", "object") narrows to Opaque. For a value whose type is already known - not `any`, not a union - that cast only lost the type: - `if (typeof f === "function") f()` failed with "not a function to call", for a plain function as well; - for a generic function nobody instantiated, the cast referenced the never emitted generic and lowering failed with "'llvm.mlir.addressof' op must reference a global". addSafeCastStatement now leaves such a value as it is. `any` is still unboxed and unions are unchanged. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
…c-function-ref # Conflicts: # tslang/test/tester/CMakeLists.txt
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Problem
typeof f === "function"(also"class","interface","object") narrowsftoOpaque. For a value whose type is already known (notany, not a union) that cast only throws the type away:if (typeof f === "function") f()failed with "not a function to call", for a plain function too.llvm.mlir.addressofop must reference a global".Fix
addSafeCastStatementleaves a value of known type as it is when the narrowed type isOpaque.anyis still unboxed at run time and unions are unchanged.Tests
New
00typeof_function_narrowing.ts(compile, JIT and corpus variants): calling a plain function and a generic function inside atypeof ... === "function"branch, an uninstantiated generic function, an arrow function in?:, andanystill narrowed at run time.Full Windows debug suite (
ctest -R "^test-"): 2739/2739 passed.Independent of #327; both touch
MLIRGenImpl.hin different functions.🤖 Generated with Claude Code