ICE when using `#[lang = "start"]` in a `#[no_std]` static library

[jeremydavis519]

Code

Reproducing the bug seems to require two crates.

Crate ice-test, file main.rs:

#![no_std]
#![feature(lang_items)]

extern crate ice_test_lib;

use core::panic::PanicInfo;

fn main() {}

#[panic_handler]
fn panic_handler(_: &PanicInfo) -> ! {
    loop {}
}

#[lang = "eh_personality"] fn eh_personality() {}

Crate ice-test-lib, file lib.rs:

#![no_std]
#![feature(lang_items)]

#[lang = "start"] fn start(_: *const u8, _: isize, _: *const *const u8) -> isize {
    0
}

I compiled using cargo build, and ice-test's Cargo.toml listed ice-test-lib as a dependency.

Meta

rustc --version --verbose:

rustc 1.52.0-nightly (acca81892 2021-03-13)
binary: rustc
commit-hash: acca818928654807ed3bc1ce0e97df118f8716c8
commit-date: 2021-03-13
host: x86_64-unknown-linux-gnu
release: 1.52.0-nightly
LLVM version: 12.0.0

Error output

error: internal compiler error: compiler/rustc_metadata/src/rmeta/decoder.rs:1157:17: get_optimized_mir: missing MIR for `DefId(4:4 ~ ice_test_lib[6871]::start)`

thread 'rustc' panicked at 'Box<Any>', /rustc/acca818928654807ed3bc1ce0e97df118f8716c8/library/std/src/panic.rs:59:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

note: the compiler unexpectedly panicked. this is a bug.

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 1.52.0-nightly (acca81892 2021-03-13) running on x86_64-unknown-linux-gnu

note: compiler flags: -C embed-bitcode=no -C debuginfo=2 -C incremental --crate-type bin

note: some of the compiler flags provided by cargo are hidden

query stack during panic:
#0 [optimized_mir] optimizing MIR for `ice_test_lib::start`
#1 [collect_and_partition_mono_items] collect_and_partition_mono_items
end of query stack

Backtrace

thread 'rustc' panicked at 'Box<Any>', /rustc/acca818928654807ed3bc1ce0e97df118f8716c8/library/std/src/panic.rs:59:5
stack backtrace:
   0: std::panicking::begin_panic
   1: std::panic::panic_any
   2: rustc_errors::HandlerInner::bug
   3: rustc_errors::Handler::bug
   4: rustc_middle::ty::context::tls::with_opt
   5: rustc_middle::util::bug::opt_span_bug_fmt
   6: rustc_middle::util::bug::bug_fmt
   7: rustc_metadata::rmeta::decoder::<impl rustc_metadata::creader::CrateMetadataRef>::get_optimized_mir
   8: rustc_metadata::rmeta::decoder::cstore_impl::provide_extern::optimized_mir
   9: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  10: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  11: rustc_data_structures::stack::ensure_sufficient_stack
  12: rustc_query_system::query::plumbing::force_query_with_job
  13: rustc_query_system::query::plumbing::get_query_impl
  14: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::optimized_mir
  15: rustc_middle::ty::<impl rustc_middle::ty::context::TyCtxt>::instance_mir
  16: rustc_mir::monomorphize::collector::collect_neighbours
  17: rustc_mir::monomorphize::collector::collect_items_rec
  18: rustc_session::utils::<impl rustc_session::session::Session>::time
  19: rustc_mir::monomorphize::collector::collect_crate_mono_items
  20: rustc_mir::monomorphize::partitioning::collect_and_partition_mono_items
  21: rustc_query_impl::<impl rustc_query_system::query::config::QueryAccessors<rustc_query_impl::plumbing::QueryCtxt> for rustc_query_impl::queries::collect_and_partition_mono_items>::compute
  22: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  23: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  24: rustc_data_structures::stack::ensure_sufficient_stack
  25: rustc_query_system::query::plumbing::force_query_with_job
  26: rustc_query_system::query::plumbing::get_query_impl
  27: <rustc_query_impl::Queries as rustc_middle::ty::query::QueryEngine>::collect_and_partition_mono_items
  28: <rustc_codegen_llvm::LlvmCodegenBackend as rustc_codegen_ssa::traits::backend::CodegenBackend>::codegen_crate
  29: rustc_interface::passes::QueryContext::enter
  30: rustc_interface::queries::Queries::ongoing_codegen
  31: rustc_interface::queries::<impl rustc_interface::interface::Compiler>::enter
  32: rustc_span::with_source_map
  33: scoped_tls::ScopedKey<T>::set

[asquared31415]

Duplicate of #79559