ICE: unexpected type in foreign function: {type error}' #121451
Description
auto-reduced (treereduce-rust):
use std::mem; macro_rules! define_reify_functions { ($( fn $name:ident $(<$($param:ident),*>)? for $(extern $abi:tt)? fn($($arg:ident: $arg_ty:ty),*) -> $ret_ty:ty; )+) => { $(pub const fn $name< $($($param,)*)? F: Fn($($arg_ty),*) -> $ret_ty + Copy >(f: F) -> $(extern $abi)? fn($($arg_ty),*) -> $ret_ty { assert!(mem::size_of::<F>() == 0, ); $(extern $abi)? fn wrapper< $($($param,)*)? F: Fn($($arg_ty),*) -> $ret_ty + Copy >($($arg: $arg_ty),*) -> $ret_ty { let f = unsafe { mem::MaybeUninit::<F>::uninit().assume_init() }; f($($arg),*) } let _f_proof = f; wrapper::< $($($param,)*)? F > })+ } } define_reify_functions! { fn _reify_to_extern_c_fn_unary<A, R> for extern "C" fn(arg: A) -> R; fn reify_to_extern_c_fn_hrt_bridge<R> for extern "C" fn(bridge: super::BridgeConfig<'_>) -> R; }original code
original:
//! Abstraction for creating `fn` pointers from any callable that *effectively* //! has the equivalent of implementing `Default`, even if the compiler neither //! provides `Default` nor allows reifying closures (i.e. creating `fn` pointers) //! other than those with absolutely no captures. //! //! More specifically, for a closure-like type to be "effectively `Default`": //! * it must be a ZST (zero-sized type): no information contained within, so //! that `Default`'s return value (if it were implemented) is unambiguous //! * it must be `Copy`: no captured "unique ZST tokens" or any other similar //! types that would make duplicating values at will unsound //! * combined with the ZST requirement, this confers a kind of "telecopy" //! ability: similar to `Copy`, but without keeping the value around, and //! instead "reconstructing" it (a noop given it's a ZST) when needed //! * it must be *provably* inhabited: no captured uninhabited types or any //! other types that cannot be constructed by the user of this abstraction //! * the proof is a value of the closure-like type itself, in a sense the //! "seed" for the "telecopy" process made possible by ZST + `Copy` //! * this requirement is the only reason an abstraction limited to a specific //! usecase is required: ZST + `Copy` can be checked with *at worst* a panic //! at the "attempted `::default()` call" time, but that doesn't guarantee //! that the value can be soundly created, and attempting to use the typical //! "proof ZST token" approach leads yet again to having a ZST + `Copy` type //! that is not proof of anything without a value (i.e. isomorphic to a //! newtype of the type it's trying to prove the inhabitation of) //! //! A more flexible (and safer) solution to the general problem could exist once //! `const`-generic parameters can have type parameters in their types: //! //! ```rust,ignore (needs future const-generics) //! extern "C" fn ffi_wrapper< //! A, R, //! F: Fn(A) -> R, //! const f: F, // <-- this `const`-generic is not yet allowed //! >(arg: A) -> R { //! f(arg) //! } //! ``` use std::mem; // FIXME(eddyb) this could be `trait` impls except for the `const fn` requirement. macro_rules! define_reify_functions { ($( fn $name:ident $(<$($param:ident),*>)? for $(extern $abi:tt)? fn($($arg:ident: $arg_ty:ty),*) -> $ret_ty:ty; )+) => { $(pub const fn $name< $($($param,)*)? F: Fn($($arg_ty),*) -> $ret_ty + Copy >(f: F) -> $(extern $abi)? fn($($arg_ty),*) -> $ret_ty { // FIXME(eddyb) describe the `F` type (e.g. via `type_name::<F>`) once panic // formatting becomes possible in `const fn`. assert!(mem::size_of::<F>() == 0, "selfless_reify: closure must be zero-sized"); $(extern $abi)? fn wrapper< $($($param,)*)? F: Fn($($arg_ty),*) -> $ret_ty + Copy >($($arg: $arg_ty),*) -> $ret_ty { let f = unsafe { // SAFETY: `F` satisfies all criteria for "out of thin air" // reconstructability (see module-level doc comment). mem::MaybeUninit::<F>::uninit().assume_init() }; f($($arg),*) } let _f_proof = f; wrapper::< $($($param,)*)? F > })+ } } define_reify_functions! { fn _reify_to_extern_c_fn_unary<A, R> for extern "C" fn(arg: A) -> R; // HACK(eddyb) this abstraction is used with `for<'a> fn(BridgeConfig<'a>) // -> T` but that doesn't work with just `reify_to_extern_c_fn_unary` // because of the `fn` pointer type being "higher-ranked" (i.e. the // `for<'a>` binder). // FIXME(eddyb) try to remove the lifetime from `BridgeConfig`, that'd help. fn reify_to_extern_c_fn_hrt_bridge<R> for extern "C" fn(bridge: super::BridgeConfig<'_>) -> R; }Version information
rustc 1.78.0-nightly (f70f19fef 2024-02-22) binary: rustc commit-hash: f70f19fef41cfdda75c92f163434c29ad046cf09 commit-date: 2024-02-22 host: x86_64-unknown-linux-gnu release: 1.78.0-nightly LLVM version: 18.1.0 Command:
/home/gh-matthiaskrgr/.rustup/toolchains/master/bin/rustc --crate-type=lib
Program output
error: internal compiler error: compiler/rustc_lint/src/types.rs:1439:32: unexpected type in foreign function: {type error} thread 'rustc' panicked at compiler/rustc_middle/src/util/bug.rs:35:44: Box<dyn Any> stack backtrace: 0: 0x7f9ec8d8caf6 - std::backtrace_rs::backtrace::libunwind::trace::hef019eae7250a090 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5 1: 0x7f9ec8d8caf6 - std::backtrace_rs::backtrace::trace_unsynchronized::h163c9c558e7f1e4e at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5 2: 0x7f9ec8d8caf6 - std::sys_common::backtrace::_print_fmt::h84a7f2dbeae8e017 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/std/src/sys_common/backtrace.rs:68:5 3: 0x7f9ec8d8caf6 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hf7737af35c1403cd at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/std/src/sys_common/backtrace.rs:44:22 4: 0x7f9ec8ddda7c - core::fmt::rt::Argument::fmt::h027f33016919ab54 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/core/src/fmt/rt.rs:142:9 5: 0x7f9ec8ddda7c - core::fmt::write::hed9b631feef55974 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/core/src/fmt/mod.rs:1120:17 6: 0x7f9ec8d814bf - std::io::Write::write_fmt::h3b1c8483aebfcef8 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/std/src/io/mod.rs:1846:15 7: 0x7f9ec8d8c8a4 - std::sys_common::backtrace::_print::h526b95c0b60f4650 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/std/src/sys_common/backtrace.rs:47:5 8: 0x7f9ec8d8c8a4 - std::sys_common::backtrace::print::h3322d8b0a1d6207a at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/std/src/sys_common/backtrace.rs:34:9 9: 0x7f9ec8d8f5eb - std::panicking::default_hook::{{closure}}::h9f07e6147b1c8a2e 10: 0x7f9ec8d8f339 - std::panicking::default_hook::h395b386ace4fbcb6 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/std/src/panicking.rs:292:9 11: 0x7f9ecbc7073c - std[d26ecb90c771e100]::panicking::update_hook::<alloc[100d4e65626f4394]::boxed::Box<rustc_driver_impl[ab901dc85bea4c82]::install_ice_hook::{closure#0}>>::{closure#0} 12: 0x7f9ec8d8fd50 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h1a188bbe7a6bf646 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/alloc/src/boxed.rs:2030:9 13: 0x7f9ec8d8fd50 - std::panicking::rust_panic_with_hook::h1eec7c1097026ee4 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/std/src/panicking.rs:786:13 14: 0x7f9ecbc9ce14 - std[d26ecb90c771e100]::panicking::begin_panic::<rustc_errors[e9339b16b54c0bc0]::ExplicitBug>::{closure#0} 15: 0x7f9ecbc99d36 - std[d26ecb90c771e100]::sys_common::backtrace::__rust_end_short_backtrace::<std[d26ecb90c771e100]::panicking::begin_panic<rustc_errors[e9339b16b54c0bc0]::ExplicitBug>::{closure#0}, !> 16: 0x7f9ecbc99a16 - std[d26ecb90c771e100]::panicking::begin_panic::<rustc_errors[e9339b16b54c0bc0]::ExplicitBug> 17: 0x7f9eca618a41 - <rustc_errors[e9339b16b54c0bc0]::diagnostic::BugAbort as rustc_errors[e9339b16b54c0bc0]::diagnostic::EmissionGuarantee>::emit_producing_guarantee 18: 0x7f9ecc07ae3c - <rustc_errors[e9339b16b54c0bc0]::DiagCtxt>::bug::<alloc[100d4e65626f4394]::string::String> 19: 0x7f9ecc11faab - rustc_middle[771c523b66a87e77]::util::bug::opt_span_bug_fmt::<rustc_span[4d20b27f335b5d92]::span_encoding::Span>::{closure#0} 20: 0x7f9ecc1033aa - rustc_middle[771c523b66a87e77]::ty::context::tls::with_opt::<rustc_middle[771c523b66a87e77]::util::bug::opt_span_bug_fmt<rustc_span[4d20b27f335b5d92]::span_encoding::Span>::{closure#0}, !>::{closure#0} 21: 0x7f9ecc103248 - rustc_middle[771c523b66a87e77]::ty::context::tls::with_context_opt::<rustc_middle[771c523b66a87e77]::ty::context::tls::with_opt<rustc_middle[771c523b66a87e77]::util::bug::opt_span_bug_fmt<rustc_span[4d20b27f335b5d92]::span_encoding::Span>::{closure#0}, !>::{closure#0}, !> 22: 0x7f9eca590ee0 - rustc_middle[771c523b66a87e77]::util::bug::bug_fmt 23: 0x7f9ece1cc3af - <rustc_lint[ee0ae86ad0d71ee5]::types::ImproperCTypesVisitor>::check_type_for_ffi.cold.0 24: 0x7f9ecd1421ca - <rustc_lint[ee0ae86ad0d71ee5]::types::ImproperCTypesVisitor>::check_type_for_ffi 25: 0x7f9ecd14161e - <rustc_lint[ee0ae86ad0d71ee5]::types::ImproperCTypesVisitor>::check_type_for_ffi_and_report_errors 26: 0x7f9ecd75d352 - <rustc_lint[ee0ae86ad0d71ee5]::types::ImproperCTypesVisitor>::check_fn 27: 0x7f9ecd75c0be - <rustc_lint[ee0ae86ad0d71ee5]::BuiltinCombinedModuleLateLintPass as rustc_lint[ee0ae86ad0d71ee5]::passes::LateLintPass>::check_fn 28: 0x7f9ecd3a8cbe - <rustc_lint[ee0ae86ad0d71ee5]::late::LateContextAndPass<rustc_lint[ee0ae86ad0d71ee5]::BuiltinCombinedModuleLateLintPass> as rustc_hir[c73f1de04e7d2c16]::intravisit::Visitor>::visit_nested_item 29: 0x7f9ecd3a70bf - rustc_lint[ee0ae86ad0d71ee5]::lint_mod 30: 0x7f9ecd3a6eb9 - rustc_query_impl[9d2321c4f9b7ef6e]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9d2321c4f9b7ef6e]::query_impl::lint_mod::dynamic_query::{closure#2}::{closure#0}, rustc_middle[771c523b66a87e77]::query::erase::Erased<[u8; 0usize]>> 31: 0x7f9ecdba4cad - rustc_query_system[1927276894a91dd8]::query::plumbing::try_execute_query::<rustc_query_impl[9d2321c4f9b7ef6e]::DynamicConfig<rustc_query_system[1927276894a91dd8]::query::caches::DefaultCache<rustc_span[4d20b27f335b5d92]::def_id::LocalModDefId, rustc_middle[771c523b66a87e77]::query::erase::Erased<[u8; 0usize]>>, false, false, false>, rustc_query_impl[9d2321c4f9b7ef6e]::plumbing::QueryCtxt, false> 32: 0x7f9ecdba35bf - rustc_query_impl[9d2321c4f9b7ef6e]::query_impl::lint_mod::get_query_non_incr::__rust_end_short_backtrace 33: 0x7f9ecdba315f - rustc_lint[ee0ae86ad0d71ee5]::late::check_crate::{closure#1} 34: 0x7f9ecdba2b5e - rustc_lint[ee0ae86ad0d71ee5]::late::check_crate 35: 0x7f9ecdb9ca65 - rustc_interface[863afa250f767019]::passes::analysis 36: 0x7f9ecdb9b759 - rustc_query_impl[9d2321c4f9b7ef6e]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[9d2321c4f9b7ef6e]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[771c523b66a87e77]::query::erase::Erased<[u8; 1usize]>> 37: 0x7f9ecdd45303 - rustc_query_system[1927276894a91dd8]::query::plumbing::try_execute_query::<rustc_query_impl[9d2321c4f9b7ef6e]::DynamicConfig<rustc_query_system[1927276894a91dd8]::query::caches::SingleCache<rustc_middle[771c523b66a87e77]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[9d2321c4f9b7ef6e]::plumbing::QueryCtxt, false> 38: 0x7f9ecdd4507f - rustc_query_impl[9d2321c4f9b7ef6e]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace 39: 0x7f9ecdd54556 - rustc_interface[863afa250f767019]::interface::run_compiler::<core[17d6b7ce805ba05e]::result::Result<(), rustc_span[4d20b27f335b5d92]::ErrorGuaranteed>, rustc_driver_impl[ab901dc85bea4c82]::run_compiler::{closure#0}>::{closure#0} 40: 0x7f9ecdfbe305 - std[d26ecb90c771e100]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[863afa250f767019]::util::run_in_thread_with_globals<rustc_interface[863afa250f767019]::util::run_in_thread_pool_with_globals<rustc_interface[863afa250f767019]::interface::run_compiler<core[17d6b7ce805ba05e]::result::Result<(), rustc_span[4d20b27f335b5d92]::ErrorGuaranteed>, rustc_driver_impl[ab901dc85bea4c82]::run_compiler::{closure#0}>::{closure#0}, core[17d6b7ce805ba05e]::result::Result<(), rustc_span[4d20b27f335b5d92]::ErrorGuaranteed>>::{closure#0}, core[17d6b7ce805ba05e]::result::Result<(), rustc_span[4d20b27f335b5d92]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[17d6b7ce805ba05e]::result::Result<(), rustc_span[4d20b27f335b5d92]::ErrorGuaranteed>> 41: 0x7f9ecdfbe132 - <<std[d26ecb90c771e100]::thread::Builder>::spawn_unchecked_<rustc_interface[863afa250f767019]::util::run_in_thread_with_globals<rustc_interface[863afa250f767019]::util::run_in_thread_pool_with_globals<rustc_interface[863afa250f767019]::interface::run_compiler<core[17d6b7ce805ba05e]::result::Result<(), rustc_span[4d20b27f335b5d92]::ErrorGuaranteed>, rustc_driver_impl[ab901dc85bea4c82]::run_compiler::{closure#0}>::{closure#0}, core[17d6b7ce805ba05e]::result::Result<(), rustc_span[4d20b27f335b5d92]::ErrorGuaranteed>>::{closure#0}, core[17d6b7ce805ba05e]::result::Result<(), rustc_span[4d20b27f335b5d92]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[17d6b7ce805ba05e]::result::Result<(), rustc_span[4d20b27f335b5d92]::ErrorGuaranteed>>::{closure#1} as core[17d6b7ce805ba05e]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0} 42: 0x7f9ec8d99725 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h1e27cc9781dd2875 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/alloc/src/boxed.rs:2016:9 43: 0x7f9ec8d99725 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h4e0d9eddec111fd1 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/alloc/src/boxed.rs:2016:9 44: 0x7f9ec8d99725 - std::sys::pal::unix::thread::Thread::new::thread_start::h8ca0c4b428df1792 at /rustc/f70f19fef41cfdda75c92f163434c29ad046cf09/library/std/src/sys/pal/unix/thread.rs:108:17 45: 0x7f9ec8a94ac3 - start_thread at ./nptl/pthread_create.c:442:8 46: 0x7f9ec8b26850 - __GI___clone3 at ./misc/../sysdeps/unix/sysv/linux/x86_64/clone3.S:81 47: 0x0 - <unknown> note: we would appreciate a bug report: https://github.com/rust-lang/rust/issues/new?labels=C-bug%2C+I-ICE%2C+T-compiler&template=ice.md note: rustc 1.78.0-nightly (f70f19fef 2024-02-22) running on x86_64-unknown-linux-gnu note: compiler flags: --crate-type lib -Z dump-mir-dir=dir query stack during panic: #0 [lint_mod] linting top-level module #1 [analysis] running analysis passes on this crate end of query stack error[E0433]: failed to resolve: there are too many leading `super` keywords --> /tmp/icemaker_global_tempdir.lTYtezpoweDB/rustc_testrunner_tmpdir_reporting.5A2nqZBfiMNU/mvce.rs:53:69 | 53 | fn reify_to_extern_c_fn_hrt_bridge<R> for extern "C" fn(bridge: super::BridgeConfig<'_>) -> R; | ^^^^^ there are too many leading `super` keywords error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0433`.