Allow MIR-inlining Drop terminators too

[scottmcm]

We've already been able to do this if drop(_1) was spelled _2 = &raw mut _1; drop_in_place(move _2), so this just needs to do the necessary updates to the query-cycle-avoidance check and to look for Drops in the normal (non-force) inliner.

This tries to avoid turning drops into drop_in_place calls if they're likely not going to be inlined, since the Call needs an extra local and an extra statement.

r? cjgillot

[scottmcm]

note to self: fix

[bors]

☔ The latest upstream changes (presumably #144543) made this pull request unmergeable. Please resolve the merge conflicts.

[cjgillot]

You'll probably need to change the mir shim pass. The current implementation only reliably supports monomorphic types.

[scottmcm]

Hmm, looks like you're right. Just trying to guard requesting the mir doesn't work since it's a concrete outer type, just with field issues. Tricky; I'll have to spend some time grokking the shim pass.

[rust-log-analyzer]

The job aarch64-gnu-llvm-19-1 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

---- [ui] tests/ui/mir/issue-107691.rs stdout ----

error: test compilation failed although it shouldn't!
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/mir/issue-107691.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/mir/issue-107691" "-A" "unused" "-A" "internal_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers" "-C" "opt-level=3"
stdout: none
--- stderr -------------------------------
##[error]error: internal compiler error: compiler/rustc_mir_transform/src/validate.rs:80:25: broken MIR in DropGlue(DefId(2:2933 ~ core[1fb6]::ptr::drop_in_place), Some(RecordResolver<'{erased}>)) (after phase change to runtime-optimized) at bb0[0]:
                                Field projection `(*_1).0` specified type `{type error}`, but actual type is `<&[u8] as Archive>::Resolver`
  --> /rustc/FAKE_PREFIX/library/core/src/ptr/mod.rs:804:1


thread 'rustc' panicked at compiler/rustc_mir_transform/src/validate.rs:80:25:
Box<dyn Any>
stack backtrace:
   0: std::panicking::begin_panic::<rustc_errors::ExplicitBug>
   1: <rustc_errors::diagnostic::BugAbort as rustc_errors::diagnostic::EmissionGuarantee>::emit_producing_guarantee
   2: <rustc_errors::diagnostic::Diag<rustc_errors::diagnostic::BugAbort>>::emit
   3: <rustc_errors::DiagCtxtHandle>::span_bug::<rustc_span::span_encoding::Span, alloc::string::String>
   4: rustc_middle::util::bug::opt_span_bug_fmt::<rustc_span::span_encoding::Span>::{closure#0}
   5: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   6: rustc_middle::ty::context::tls::with_context_opt::<rustc_middle::ty::context::tls::with_opt<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}, !>
   7: rustc_middle::util::bug::span_bug_fmt::<rustc_span::span_encoding::Span>
   8: <rustc_mir_transform::validate::CfgChecker>::fail::<alloc::string::String>
   9: <rustc_mir_transform::validate::Validator as rustc_mir_transform::pass_manager::MirPass>::run_pass
  10: rustc_mir_transform::pass_manager::run_passes_inner
  11: rustc_mir_transform::shim::make_shim
      [... omitted 3 frames ...]
  12: <rustc_middle::ty::context::TyCtxt>::instance_mir
  13: rustc_mir_transform::inline::try_instance_mir
  14: rustc_mir_transform::inline::process_blocks::<rustc_mir_transform::inline::NormalInliner>
  15: <rustc_mir_transform::inline::Inline as rustc_mir_transform::pass_manager::MirPass>::run_pass
  16: rustc_mir_transform::pass_manager::run_passes_inner
  17: rustc_mir_transform::run_optimization_passes
  18: rustc_mir_transform::optimized_mir
      [... omitted 3 frames ...]
  19: rustc_mir_transform::cross_crate_inline::cross_crate_inlinable
      [... omitted 3 frames ...]
  20: rustc_passes::reachable::recursively_reachable
  21: rustc_passes::reachable::reachable_set
      [... omitted 3 frames ...]
  22: <rustc_metadata::rmeta::encoder::EncodeContext>::encode_crate_root
  23: <rustc_metadata::rmeta::encoder::encode_metadata::{closure#3} as core::ops::function::FnOnce<(rustc_middle::ty::context::TyCtxt, &std::path::Path)>>::call_once
  24: rustc_metadata::rmeta::encoder::encode_metadata
  25: rustc_metadata::fs::encode_and_write_metadata
  26: rustc_interface::passes::start_codegen
  27: <rustc_interface::queries::Linker>::codegen_and_build_linker
  28: <std::thread::local::LocalKey<core::cell::Cell<*const ()>>>::with::<rustc_middle::ty::context::tls::enter_context<<rustc_middle::ty::context::GlobalCtxt>::enter<rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}, core::option::Option<rustc_interface::queries::Linker>>::{closure#1}, core::option::Option<rustc_interface::queries::Linker>>::{closure#0}, core::option::Option<rustc_interface::queries::Linker>>
  29: <rustc_middle::ty::context::TyCtxt>::create_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>::{closure#2}::{closure#0}>
  30: <rustc_interface::passes::create_and_enter_global_ctxt<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>::{closure#2} as core::ops::function::FnOnce<(&rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy>, &std::sync::once_lock::OnceLock<rustc_middle::ty::context::GlobalCtxt>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_middle::arena::Arena>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_hir::Arena>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2})>>::call_once::{shim:vtable#0}
  31: <alloc::boxed::Box<dyn for<'a> core::ops::function::FnOnce<(&'a rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy>, &'a std::sync::once_lock::OnceLock<rustc_middle::ty::context::GlobalCtxt<'a>>, &'a rustc_data_structures::sync::worker_local::WorkerLocal<rustc_middle::arena::Arena<'a>>, &'a rustc_data_structures::sync::worker_local::WorkerLocal<rustc_hir::Arena<'a>>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}), Output = core::option::Option<rustc_interface::queries::Linker>>> as core::ops::function::FnOnce<(&rustc_session::session::Session, rustc_middle::ty::context::CurrentGcx, alloc::sync::Arc<rustc_data_structures::jobserver::Proxy>, &std::sync::once_lock::OnceLock<rustc_middle::ty::context::GlobalCtxt>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_middle::arena::Arena>, &rustc_data_structures::sync::worker_local::WorkerLocal<rustc_hir::Arena>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2})>>::call_once
  32: rustc_interface::passes::create_and_enter_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>
  33: <scoped_tls::ScopedKey<rustc_span::SessionGlobals>>::set::<rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}::{closure#0}, ()>
  34: rustc_span::create_session_globals_then::<(), rustc_interface::util::run_in_thread_with_globals<rustc_interface::util::run_in_thread_pool_with_globals<rustc_interface::interface::run_compiler<(), rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, ()>::{closure#0}, ()>::{closure#0}::{closure#0}::{closure#0}>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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: please make sure that you have updated to the latest nightly

note: rustc 1.90.0-nightly (ed304d325 2025-08-01) running on aarch64-unknown-linux-gnu

note: compiler flags: -Z threads=1 -Z simulate-remapped-rust-src-base=/rustc/FAKE_PREFIX -Z translate-remapped-path-to-local-path=no -Z ignore-directory-in-diagnostics-source-blocks=/cargo -Z ignore-directory-in-diagnostics-source-blocks=/checkout/vendor -C codegen-units=1 -Z ui-testing -Z deduplicate-diagnostics=no -Z write-long-types-to-disk=no -C strip=debuginfo -C prefer-dynamic -C rpath -C debuginfo=0 -C opt-level=3

query stack during panic:
#0 [mir_shims] generating MIR shim for `core::ptr::drop_in_place`, instance=DropGlue(DefId(2:2933 ~ core[1fb6]::ptr::drop_in_place), Some(RecordResolver<'{erased}>))
#1 [optimized_mir] optimizing MIR for `<impl at /checkout/tests/ui/mir/issue-107691.rs:34:1: 36:23>::resolve`
#2 [cross_crate_inlinable] whether the item should be made inlinable across crates
#3 [reachable_set] reachability
end of query stack
error: aborting due to 1 previous error
------------------------------------------