TypeChecker: reject zero-length static array element types#16718
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genisis0x wants to merge 1 commit into
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TypeChecker: reject zero-length static array element types#16718genisis0x wants to merge 1 commit into
genisis0x wants to merge 1 commit into
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DeclarationTypeChecker::endVisit(ArrayTypeName) rejects `uint256[0]` (and similar) with TypeError 1406 "Array with zero length specified.", but that visitor only runs for ArrayTypeName declarations. Static array types written as expressions — e.g. inside `abi.decode((uint256[0][]))` — are constructed in TypeChecker::visit(IndexAccess) through the TypeType branch, which never validated the literal length. The zero-length type then propagated to codegen and triggered an ICE in ABIFunctions::abiDecodingFunctionArrayAvailableLength (and other callers that assume `calldataStride() > 0`). Apply the same rejection here as a fatal type error so the existing 1406 diagnostic is the only message users see and codegen is never reached with a zero-length element type. Fixes argotorg#16627
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Summary
`DeclarationTypeChecker::endVisit(ArrayTypeName)` rejects `uint256[0]` (and similar) with TypeError 1406 "Array with zero length specified.", but that visitor only runs for ArrayTypeName declarations. Static array types written as expressions — e.g. inside `abi.decode((uint256[0][]))` — are constructed in `TypeChecker::visit(IndexAccess)` through the TypeType branch, which never validated the literal length. The zero-length type then propagated to codegen and triggered an ICE in `ABIFunctions::abiDecodingFunctionArrayAvailableLength` (and other callers that assume `calldataStride() > 0`).
Apply the same rejection here as a fatal type error so the existing 1406 diagnostic is the only message users see and codegen is never reached with a zero-length element type.
Fixes #16627
Test plan