hyperledger-solang/solang

Compiling any contract containing an assembly { } block with --target soroban crashes the compiler: thread 'main' panicked at src/sema/yul/builtin.rs:25:32: not implemented Yul/inline assembly is (correctly) unsupported on Soroban — Yul builtins are EVM opcodes with no Soroban equivalent — but the compiler should reject it with a user-facing error, not panic. The panic comes from YulBuiltinPrototype::is_available, whose Target::Soroban arm is unimplemented!() (src/sema/yul/builtin.rs:25). This fires before the existing "not available for target" diagnostic path at src/sema/yul/expression.rs:391. Repro: pragma solidity ^0.8.20; contract C { function add(uint64 a, uint64 b) public pure returns (uint64 r) { assembly { r := add(a, b) } } } solang compile --target soroban c.sol → panic (EVM target compiles fine). Expected: a clean compile error stating inline assembly is not supported on Soroban.

Current coverage (minimal — 2 tests): i128_u128.rs: uint128_high_limb_not_dropped_on_encode, i128_u128_encode_decode_coverage (a solid edge-value round-trip sweep). math.rs: i128_ops, u128_ops. abi_encode.rs: abi_encode_uint128_roundtrip, abi_encode_int128_roundtrip. Gaps: the existing file is ABI-round-trip only. No casts, storage, comparison, bitwise, unchecked overflow, or type(T).min/max. Task Expand tests/soroban_testcases/i128_u128.rs to the full shared integer test matrix below (keep the existing two tests — the round-trip sweep already satisfies row A well). Match the file's existing style. Test matrix (apply to both int128 and uint128): A. ABI round-trip — already covered by i128_u128_encode_decode_coverage; additionally pass an object-form value host-side and assert clean decode (guards decode_i128 tag handling for the negative small form). B. Arithmetic — + - * / %, unary -; verify ** support. C. Overflow — checked default reverts on max+1, min-1, unsigned 0-1 (

This is part of a per-width-class push to give every Soroban-native integer type the same exhaustive coverage that strings.rs / bytes_pass.rs gave the byte types (23 and 47 focused #[test]s respectively). Soroban has no distinct type per Solidity width — every intN/uintN rounds up to the nearest native container (integer_width_rounding.rs), and the encoder only has arms for 32 / 64 / 128 / 256 (src/codegen/targets/soroban/encoding.rs). So the four container widths are the real test units, each pairing the signed and unsigned form. int32/uint32 map to the Soroban I32Val/U32Val small (inline) form — the 32-bit value always fits in the 56-bit ScVal body (tags::I32 = 5, tags::U32 = 4), so there is no object/host form and no small↔object boundary to test. That makes this the simplest of the four and a good starter. Current coverage (scattered, not exhaustive): math.rs: u32_roundtrip, u32_ops, i32_roundtrip, i32_ops. abi_encode.rs: abi_encode_uint32_roundtrip, abi_encode_int32_roundtr