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[soundness] hy-check(const_init): type-parameter shadows on const conversions, type ascriptions, and file constants bypass HYB-E6003 #3851
Description
Summary
In compiler/crates/hy-check/src/const_init.rs, expr_is_constant_inner, is_const_conversion_target, is_const_string_conversion_target, is_const_string_expr, is_const_allowed_ty, and ident_is_constant check st.env_lookup and file-level declarations, but do not check whether a function's generic type parameter (st.type_params) shadows a type alias, conversion target, type ascription, or file-level const:
type my_int = int; fn f[my_int]() { const c = my_int(1) }andfn f[my_int]() { const c my_int = 1 }treatmy_intas the file-level aliasintinstead of the function's type parametermy_int, accepting a Go non-constant type conversion/ascription.const k = 42; fn f[k]() { const c = k + 1 }andconst s = "abc"; fn f[s]() { const n = len(s) }resolvek/sto the file-level constant even though the identifier is shadowed in function scope by the type parameter.resolve_type_aliasinconst_init.rsdid not stop when an intermediate/target name was shadowed bystructs,struct_type_params, orenums.
Minimal Reproducer
type my_int = int
const k = 42
fn f[my_int, k]() {
const c = my_int(1)
const d my_int = 1
const e = k + 1
_ = c
_ = d
_ = e
}
fn main() {}Expected Behavior
Reject all three local const declarations with HYB-E6003.
Activity
dextermos-dev commentedon Nov 6, 2026
Hello! We have implemented and submitted a complete fix for this issue in #3867.
Solution Overview:
s.type_params.contains(ty_name)checks inexpr_is_constant_inner(Expr::Call) andis_const_conversion_targetso generic type parameters shadowing aliases or primitive conversion names cannot be evaluated as constants.is_const_allowed_tyto inspectst: Option<&FnState>, rejecting any ascribed type whose named root or alias target matches an in-scope type parameter.ident_is_constantandis_const_string_expr, verifiedst.type_params.contains(name)to ensure function type parameters correctly shadow file-level constants, rejecting non-constant references withHYB-E6003.compiler/crates/hy-check/tests/issue_3851_const_init_type_param_shadow.rscovering all reproducer cases and positive controls.Settlement Wallet (USDC on Base):
0x8366bCe3a2D379De7656D7A67015789FaF999f20hy-check(const_init): reject type-parameter shadows on const conversi…
hy-check(const_init): reject type-parameter shadows on const conversi…
hy-check(const_init): reject type-parameter shadows on const conversi…
Merge PR limitlessprojects#3867: hy-check(const_init) reject type-par…
hy-check(const_init): stop alias-chain resolution on intermediate typ…