`expr.rs` index out of bounds: `the len is 0 but the index is 0` #123442

Naserume · 2024-04-04T01:23:07Z

Code

(reduced)

extern crate issue_15562;

fn main() {
    {
        transmute();
    }
}
extern "rust-intrinsic" fn transmute() {}

(original)

//@ run-pass
//@ aux-build:issue-15562.rs

//@ pretty-expanded FIXME #23616

extern crate issue_15562 as i;

pub fn main() {
    unsafe {
        transmute();
        i::transmute();
    }
}

// We declare this so we don't run into unresolved symbol errors
// The above extern is NOT `extern "rust-intrinsic"` and thus
// means it'll try to find a corresponding symbol to link to.
#[no_mangle]
pub unsafe extern "rust-intrinsic" fn transmute() {}

Error output

error[E0463]: can't find crate for `issue_15562`
 --> ./CF20DE9D60924DCBAD5950D10D572176B7F7ED570B099E173A86F64C0AAB2C6A.rs:1:1
  |
1 | extern crate issue_15562;
  | ^^^^^^^^^^^^^^^^^^^^^^^^^ can't find crate

error[E0658]: intrinsics are subject to change
 --> ./CF20DE9D60924DCBAD5950D10D572176B7F7ED570B099E173A86F64C0AAB2C6A.rs:8:8
  |
8 | extern "rust-intrinsic" fn transmute() {}
  |        ^^^^^^^^^^^^^^^^
  |
  = help: add `#![feature(intrinsics)]` to the crate attributes to enable
  = note: this compiler was built on 2024-04-03; consider upgrading it if it is out of date

error[E0094]: intrinsic has wrong number of type parameters: found 0, expected 2
 --> ./CF20DE9D60924DCBAD5950D10D572176B7F7ED570B099E173A86F64C0AAB2C6A.rs:8:37
  |
8 | extern "rust-intrinsic" fn transmute() {}
  |                                     ^ expected 2 type parameters

Backtrace

thread 'rustc' panicked at compiler/rustc_hir_typeck/src/expr.rs:550:28:
index out of bounds: the len is 0 but the index is 0
stack backtrace:
   0:        0x10e092797 - std::backtrace::Backtrace::create::hde801799bfcf1a18
   1:        0x10e0926e5 - std::backtrace::Backtrace::force_capture::h19ae693dac8964df
   2:        0x116c3dcfb - std[38e870d6de0dab70]::panicking::update_hook::<alloc[43ccfcebb6346d8b]::boxed::Box<rustc_driver_impl[b21b79e6d003739c]::install_ice_hook::{closure#0}>>::{closure#0}
   3:        0x10e0ac564 - std::panicking::rust_panic_with_hook::h980ef0202c45a742
   4:        0x10e0abea4 - std::panicking::begin_panic_handler::{{closure}}::h6974c7b825f3e848
   5:        0x10e0a9379 - std::sys_common::backtrace::__rust_end_short_backtrace::h8e1c545181895940
   6:        0x10e0abbd6 - _rust_begin_unwind
   7:        0x10e111355 - core::panicking::panic_fmt::h47e8c306b2b8d99c
   8:        0x10e111556 - core::panicking::panic_bounds_check::h7de25c62010f13eb
   9:        0x1170bb209 - <rustc_hir_typeck[b79567a4313f5def]::fn_ctxt::FnCtxt>::check_expr_path
  10:        0x1170b951f - <rustc_hir_typeck[b79567a4313f5def]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  11:        0x117098eb6 - <rustc_hir_typeck[b79567a4313f5def]::fn_ctxt::FnCtxt>::check_call
  12:        0x117196e29 - <rustc_hir_typeck[b79567a4313f5def]::fn_ctxt::FnCtxt>::check_expr_kind
  13:        0x1170b95db - <rustc_hir_typeck[b79567a4313f5def]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  14:        0x1170f05c6 - <rustc_hir_typeck[b79567a4313f5def]::fn_ctxt::FnCtxt>::check_stmt
  15:        0x1170f0dac - <rustc_hir_typeck[b79567a4313f5def]::fn_ctxt::FnCtxt>::check_block_with_expected
  16:        0x1170b95db - <rustc_hir_typeck[b79567a4313f5def]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  17:        0x1170f0dea - <rustc_hir_typeck[b79567a4313f5def]::fn_ctxt::FnCtxt>::check_block_with_expected
  18:        0x1170b95db - <rustc_hir_typeck[b79567a4313f5def]::fn_ctxt::FnCtxt>::check_expr_with_expectation_and_args
  19:        0x1170bb595 - <rustc_hir_typeck[b79567a4313f5def]::fn_ctxt::FnCtxt>::check_return_expr
  20:        0x11718103e - rustc_hir_typeck[b79567a4313f5def]::check::check_fn
  21:        0x1171777e9 - rustc_hir_typeck[b79567a4313f5def]::typeck
  22:        0x11806c11a - rustc_query_impl[3605ca4bc1475aca]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[3605ca4bc1475aca]::query_impl::typeck::dynamic_query::{closure#2}::{closure#0}, rustc_middle[292fdd7a6f274851]::query::erase::Erased<[u8; 8usize]>>
  23:        0x117eef00c - rustc_query_system[854611ef8e5fc0a7]::query::plumbing::try_execute_query::<rustc_query_impl[3605ca4bc1475aca]::DynamicConfig<rustc_query_system[854611ef8e5fc0a7]::query::caches::VecCache<rustc_hir[9efa7d06bb4f22]::hir_id::OwnerId, rustc_middle[292fdd7a6f274851]::query::erase::Erased<[u8; 8usize]>>, false, false, false>, rustc_query_impl[3605ca4bc1475aca]::plumbing::QueryCtxt, false>
  24:        0x11808ef1b - rustc_query_impl[3605ca4bc1475aca]::query_impl::typeck::get_query_non_incr::__rust_end_short_backtrace
  25:        0x116e7a3e7 - <rustc_middle[292fdd7a6f274851]::hir::map::Map>::par_body_owners::<rustc_hir_analysis[76877c2d5917afe]::check_crate::{closure#4}>::{closure#0}
  26:        0x116f8200c - rustc_hir_analysis[76877c2d5917afe]::check_crate
  27:        0x1173e8470 - rustc_interface[9070b66c4f6dc5ef]::passes::analysis
  28:        0x11806c16a - rustc_query_impl[3605ca4bc1475aca]::plumbing::__rust_begin_short_backtrace::<rustc_query_impl[3605ca4bc1475aca]::query_impl::analysis::dynamic_query::{closure#2}::{closure#0}, rustc_middle[292fdd7a6f274851]::query::erase::Erased<[u8; 1usize]>>
  29:        0x117e56b6e - rustc_query_system[854611ef8e5fc0a7]::query::plumbing::try_execute_query::<rustc_query_impl[3605ca4bc1475aca]::DynamicConfig<rustc_query_system[854611ef8e5fc0a7]::query::caches::SingleCache<rustc_middle[292fdd7a6f274851]::query::erase::Erased<[u8; 1usize]>>, false, false, false>, rustc_query_impl[3605ca4bc1475aca]::plumbing::QueryCtxt, false>
  30:        0x118076537 - rustc_query_impl[3605ca4bc1475aca]::query_impl::analysis::get_query_non_incr::__rust_end_short_backtrace
  31:        0x116bee547 - <rustc_interface[9070b66c4f6dc5ef]::queries::QueryResult<&rustc_middle[292fdd7a6f274851]::ty::context::GlobalCtxt>>::enter::<core[14fbfc68cf988ae3]::result::Result<(), rustc_span[c77fbea70134c538]::ErrorGuaranteed>, rustc_driver_impl[b21b79e6d003739c]::run_compiler::{closure#0}::{closure#1}::{closure#3}>
  32:        0x116c44d1f - rustc_interface[9070b66c4f6dc5ef]::interface::run_compiler::<core[14fbfc68cf988ae3]::result::Result<(), rustc_span[c77fbea70134c538]::ErrorGuaranteed>, rustc_driver_impl[b21b79e6d003739c]::run_compiler::{closure#0}>::{closure#0}
  33:        0x116c37cad - std[38e870d6de0dab70]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[9070b66c4f6dc5ef]::util::run_in_thread_with_globals<rustc_interface[9070b66c4f6dc5ef]::util::run_in_thread_pool_with_globals<rustc_interface[9070b66c4f6dc5ef]::interface::run_compiler<core[14fbfc68cf988ae3]::result::Result<(), rustc_span[c77fbea70134c538]::ErrorGuaranteed>, rustc_driver_impl[b21b79e6d003739c]::run_compiler::{closure#0}>::{closure#0}, core[14fbfc68cf988ae3]::result::Result<(), rustc_span[c77fbea70134c538]::ErrorGuaranteed>>::{closure#0}, core[14fbfc68cf988ae3]::result::Result<(), rustc_span[c77fbea70134c538]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[14fbfc68cf988ae3]::result::Result<(), rustc_span[c77fbea70134c538]::ErrorGuaranteed>>
  34:        0x116c4ab7f - <<std[38e870d6de0dab70]::thread::Builder>::spawn_unchecked_<rustc_interface[9070b66c4f6dc5ef]::util::run_in_thread_with_globals<rustc_interface[9070b66c4f6dc5ef]::util::run_in_thread_pool_with_globals<rustc_interface[9070b66c4f6dc5ef]::interface::run_compiler<core[14fbfc68cf988ae3]::result::Result<(), rustc_span[c77fbea70134c538]::ErrorGuaranteed>, rustc_driver_impl[b21b79e6d003739c]::run_compiler::{closure#0}>::{closure#0}, core[14fbfc68cf988ae3]::result::Result<(), rustc_span[c77fbea70134c538]::ErrorGuaranteed>>::{closure#0}, core[14fbfc68cf988ae3]::result::Result<(), rustc_span[c77fbea70134c538]::ErrorGuaranteed>>::{closure#0}::{closure#0}, core[14fbfc68cf988ae3]::result::Result<(), rustc_span[c77fbea70134c538]::ErrorGuaranteed>>::{closure#1} as core[14fbfc68cf988ae3]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  35:        0x10e0b574b - std::sys::pal::unix::thread::Thread::new::thread_start::hb7c71ee179e441c0
  36:     0x7ff818270202 - __pthread_start


rustc version: 1.79.0-nightly (4fd4797c2 2024-04-03)
platform: x86_64-apple-darwin

query stack during panic:
#0 [typeck] type-checking `main`
#1 [analysis] running analysis passes on this crate
end of query stack

The text was updated successfully, but these errors were encountered:

compiler-errors · 2024-04-04T03:29:42Z

Please try to minimize the example as much as possible:

fn main() {
    transmute();
}

extern "rust-intrinsic" fn transmute() {}

gurry · 2024-04-05T11:08:11Z

@rustbot claim

compiler-errors · 2024-04-06T02:08:41Z

@gurry: heads up that @estebank already put up a fix

gurry · 2024-04-06T04:38:36Z

Thanks @compiler-errors. Just want to add that some other intrinsics also ICE.

For example:

fn main() {
    read_via_copy();
}

extern "rust-intrinsic" fn read_via_copy() {}

ICEs as well.

compiler-errors · 2024-04-06T05:30:45Z

Interesting @gurry -- I wonder if we should perhaps fix this in a less specific way than #123526. I wonder if we should instead detect that the extern "rust-intrinsic" declaration is not valid b/c feature(intrinsics) has not been enabled in the crate...

If not, then I'd be glad to review a PR that fixes whatever other intrinsics you find to make too many assumptions in the compiler.

…errors Do not ICE when calling incorrectly defined `transmute` intrinsic Fix rust-lang#123442

Rollup merge of rust-lang#123526 - estebank:issue-123442, r=compiler-errors Do not ICE when calling incorrectly defined `transmute` intrinsic Fix rust-lang#123442

gurry · 2024-04-07T07:39:15Z

I wonder if we should instead detect that the extern "rust-intrinsic" declaration is not valid b/c feature(intrinsics) has not been enabled in the crate...

Even adding feature(intrinsics) does not prevent the ICE unfortunately.

It happens in lower_intrinsics.rs due to the wrong number of arguments e.g. here for read_via_copy:

rust/compiler/rustc_mir_transform/src/lower_intrinsics.rs

Lines 176 to 178 in af25253

    
           let [arg] = args.as_slice() else { 
        
               span_bug!(terminator.source_info.span, "Wrong number of arguments"); 
        
           };

span_bug!(..., "Wrong number of arguments...") occurs for a lot of intrinsics in this file. I'm guessing all of them will ICE under the conditions in this issue.

To fix it, we could extend what's done for transmute in #123526 to all intrinsics, maybe leveraging this code to know how many args are expected for any given intrinsic:

rust/compiler/rustc_hir_analysis/src/check/intrinsic.rs

Line 223 in af25253

let (n_tps, n_cts, inputs, output) = match intrinsic_name {

gurry · 2024-04-07T07:54:03Z

I have opened #123587

gurry · 2024-04-08T01:42:35Z

Looks like intrinsics are expected to ICE if used wrongly (see comment: #123587 (comment)) so #123587 I opened has been rightly closed.

But that mean that transmute should also ICE in these conditions. However, in the present issue it was ICEing for the wrong reason i.e. out of bound access . So #123526 does the right thing by stopping that. However, IMHO it should not taint the context and let it go to MIR lowering and then let it ICE there. That keeps transmute consistent with other intrinsics' behaviour as noted above.

Thoughts @estebank & @compiler-errors? If you guys agree I can open a PR to remove the tainting.

compiler-errors · 2024-04-08T01:44:21Z

See #123603 which takes a different approach

gurry · 2024-04-08T03:52:17Z

Nice!

Naserume added C-bug Category: This is a bug. I-ICE Issue: The compiler panicked, giving an Internal Compilation Error (ICE) ❄️ T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Apr 4, 2024

rustbot added the needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. label Apr 4, 2024

jieyouxu added A-intrinsics Area: Intrinsics S-has-mcve Status: A Minimal Complete and Verifiable Example has been found for this issue and removed needs-triage This issue may need triage. Remove it if it has been sufficiently triaged. labels Apr 4, 2024

rustbot assigned gurry Apr 5, 2024

estebank mentioned this issue Apr 6, 2024

Do not ICE when calling incorrectly defined transmute intrinsic #123526

Merged

matthiaskrgr added a commit to matthiaskrgr/rust that referenced this issue Apr 6, 2024

Rollup merge of rust-lang#123526 - estebank:issue-123442, r=compiler-…

fc2dbbb

…errors Do not ICE when calling incorrectly defined `transmute` intrinsic Fix rust-lang#123442

bors closed this as completed in aa53bc0 Apr 6, 2024

rust-timer added a commit to rust-lang-ci/rust that referenced this issue Apr 6, 2024

Unrolled build for rust-lang#123526

5efc43b

Rollup merge of rust-lang#123526 - estebank:issue-123442, r=compiler-errors Do not ICE when calling incorrectly defined `transmute` intrinsic Fix rust-lang#123442

gurry mentioned this issue Apr 7, 2024

Intrinsics declared with wrong arg count ICE #123587

Closed

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`expr.rs` index out of bounds: `the len is 0 but the index is 0` #123442

`expr.rs` index out of bounds: `the len is 0 but the index is 0` #123442

Naserume commented Apr 4, 2024 •

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compiler-errors commented Apr 4, 2024 •

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gurry commented Apr 8, 2024

expr.rs index out of bounds: the len is 0 but the index is 0 #123442

expr.rs index out of bounds: the len is 0 but the index is 0 #123442

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gurry commented Apr 8, 2024

`expr.rs` index out of bounds: `the len is 0 but the index is 0` #123442

`expr.rs` index out of bounds: `the len is 0 but the index is 0` #123442

Naserume commented Apr 4, 2024 •

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compiler-errors commented Apr 4, 2024 •

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