ICE with cross-crate inlined `asm!`

[thepowersgang]

Code

EDIT: Minimised

ice_asm/src/lib.rs

#![feature(asm)]
#[inline]   
pub unsafe fn inw() {
    asm!("");
}

ice_asm/src/main.rs

fn main() {
    unsafe { ice_asm::inw() }
}

Meta

rustc --version --verbose:

rustc 1.45.0-nightly (215f2d329 2020-05-22)
binary: rustc
commit-hash: 215f2d3294b08dbdcf8f7d40de21ef1e7eae0a2d
commit-date: 2020-05-22
host: x86_64-unknown-linux-gnu
release: 1.45.0-nightly
LLVM version: 10.0

Error output

   Compiling ice_asm v0.1.0 (/home/tpg/Projects/rust_os/temp/ice_asm)
thread 'rustc' panicked at 'missing specialization: `<rustc_metadata::rmeta::decoder::DecodeContext as SpecializedDecoder<&[rustc_ast::ast::InlineAsmTemplatePiece]>>::specialized_decode` not overridden', /rustc/215f2d3294b08dbdcf8f7d40de21ef1e7eae0a2d/src/libstd/macros.rs:16:9
stack backtrace:
   0: backtrace::backtrace::libunwind::trace
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/libunwind.rs:86
   1: backtrace::backtrace::trace_unsynchronized
             at /cargo/registry/src/github.com-1ecc6299db9ec823/backtrace-0.3.46/src/backtrace/mod.rs:66
   2: std::sys_common::backtrace::_print_fmt
             at src/libstd/sys_common/backtrace.rs:78
   3: <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt
             at src/libstd/sys_common/backtrace.rs:59
   4: core::fmt::write
             at src/libcore/fmt/mod.rs:1069
   5: std::io::Write::write_fmt
             at src/libstd/io/mod.rs:1537
   6: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:62
   7: std::sys_common::backtrace::print
             at src/libstd/sys_common/backtrace.rs:49
   8: std::panicking::default_hook::{{closure}}
             at src/libstd/panicking.rs:198
   9: std::panicking::default_hook
             at src/libstd/panicking.rs:218
  10: rustc_driver::report_ice
  11: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:490
  12: rust_begin_unwind
             at src/libstd/panicking.rs:388
  13: std::panicking::begin_panic_fmt
             at src/libstd/panicking.rs:342
  14: <E as serialize::serialize::SpecializationError>::not_found
  15: <rustc_middle::mir::Terminator as serialize::serialize::Decodable>::decode
  16: serialize::serialize::Decoder::read_option
  17: <rustc_middle::mir::BasicBlockData as serialize::serialize::Decodable>::decode
  18: serialize::serialize::Decoder::read_seq
  19: <rustc_middle::mir::Body as serialize::serialize::Decodable>::decode
  20: rustc_metadata::rmeta::decoder::<impl rustc_metadata::creader::CrateMetadataRef>::get_optimized_mir
  21: rustc_metadata::rmeta::decoder::cstore_impl::provide_extern::optimized_mir
  22: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::optimized_mir>::compute
  23: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  24: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  25: rustc_data_structures::stack::ensure_sufficient_stack
  26: rustc_query_system::query::plumbing::get_query_impl
  27: rustc_middle::ty::<impl rustc_middle::ty::context::TyCtxt>::instance_mir
  28: rustc_mir::monomorphize::collector::collect_neighbours
  29: rustc_data_structures::stack::ensure_sufficient_stack
  30: rustc_mir::monomorphize::collector::collect_items_rec
  31: rustc_mir::monomorphize::collector::collect_items_rec
  32: rustc_mir::monomorphize::collector::collect_crate_mono_items
  33: rustc_mir::monomorphize::partitioning::collect_and_partition_mono_items
  34: rustc_middle::ty::query::<impl rustc_query_system::query::config::QueryAccessors<rustc_middle::ty::context::TyCtxt> for rustc_middle::ty::query::queries::collect_and_partition_mono_items>::compute
  35: rustc_middle::dep_graph::<impl rustc_query_system::dep_graph::DepKind for rustc_middle::dep_graph::dep_node::DepKind>::with_deps
  36: rustc_query_system::dep_graph::graph::DepGraph<K>::with_task_impl
  37: rustc_data_structures::stack::ensure_sufficient_stack
  38: rustc_query_system::query::plumbing::get_query_impl
  39: rustc_codegen_ssa::base::codegen_crate
  40: <rustc_codegen_llvm::LlvmCodegenBackend as rustc_codegen_ssa::traits::backend::CodegenBackend>::codegen_crate
  41: rustc_interface::passes::start_codegen
  42: rustc_middle::ty::context::tls::enter_global
  43: rustc_interface::queries::Queries::ongoing_codegen
  44: rustc_interface::interface::run_compiler_in_existing_thread_pool
  45: scoped_tls::ScopedKey<T>::set
  46: rustc_ast::attr::with_globals
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

error: internal compiler error: unexpected panic

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

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

note: rustc 1.45.0-nightly (215f2d329 2020-05-22) 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] processing `ice_asm::inw`
#1 [collect_and_partition_mono_items] collect_and_partition_mono_items
end of query stack
error: could not compile `ice_asm`.

[JohnTitor]

I think it's related to #72386.

[Aaron1011]

It looks like a duplicate.

[JohnTitor]

Yeah, confirmed #72400 fixes this, closing in favor of the above issue.

[thepowersgang]

(I did see that other ticket, but since the panic location was different - I opened a second ticket)