Compiler panic on programs using to_string()

[jberthold]

When extracting smir json for a program that contains a call to `to_string()`, the `printer.rs` code crashes with

thread 'rustc' panicked at compiler/rustc_middle/src/ty/predicate.rs:533:9:
`<[core::fmt::rt::Argument<'_>] as std::marker::Sized>` has escaping bound vars, so it cannot be wrapped in a dummy binder.

Programs that exhibit this are tests/integration/failing/{defined-trait,std-to-string}.rs

The backtrace is here:

$ RUST_BACKTRACE=1 deps/smir_pretty/run.sh -Z no-codegen kmir/src/tests/integration/data/run-rs/strings-chars/std-to-string.rs 

thread 'rustc' panicked at compiler/rustc_middle/src/ty/predicate.rs:533:9:
`<[core::fmt::rt::Argument<'_>] as std::marker::Sized>` has escaping bound vars, so it cannot be wrapped in a dummy binder.
stack backtrace:
   0: rust_begin_unwind
   1: core::panicking::panic_fmt
   2: <rustc_middle::ty::predicate::Predicate as rustc_type_ir::upcast::UpcastFrom<rustc_middle::ty::context::TyCtxt, rustc_type_ir::predicate::TraitRef<rustc_middle::ty::context::TyCtxt>>>::upcast_from
   3: rustc_trait_selection::traits::type_known_to_meet_bound_modulo_regions
   4: rustc_ty_utils::common_traits::is_item_raw
      [... omitted 2 frames ...]
   5: rustc_middle::query::plumbing::query_get_at::<rustc_query_system::query::caches::DefaultCache<rustc_middle::ty::PseudoCanonicalInput<rustc_middle::ty::Ty>, rustc_middle::query::erase::Erased<[u8; 1]>>>
   6: <rustc_middle::ty::Ty>::is_sized
   7: rustc_ty_utils::layout::layout_of
      [... omitted 2 frames ...]
   8: <rustc_middle::ty::layout::LayoutCx as rustc_middle::ty::layout::LayoutOf>::spanned_layout_of
   9: core::iter::adapters::try_process::<core::iter::adapters::by_ref_sized::ByRefSized<core::iter::adapters::map::Map<core::slice::iter::Iter<rustc_middle::ty::FieldDef>, rustc_ty_utils::layout::layout_of_uncached::{closure#13}::{closure#0}>>, rustc_abi::layout::ty::TyAndLayout<rustc_middle::ty::Ty>, core::result::Result<core::convert::Infallible, &rustc_middle::ty::layout::LayoutError>, <core::iter::adapters::map::Map<core::slice::iter::Iter<rustc_middle::ty::FieldDef>, rustc_ty_utils::layout::layout_of_uncached::{closure#13}::{closure#0}> as core::iter::traits::iterator::Iterator>::try_collect<rustc_index::vec::IndexVec<rustc_abi::layout::ty::FieldIdx, rustc_abi::layout::ty::TyAndLayout<rustc_middle::ty::Ty>>>::{closure#0}, rustc_index::vec::IndexVec<rustc_abi::layout::ty::FieldIdx, rustc_abi::layout::ty::TyAndLayout<rustc_middle::ty::Ty>>>
  10: core::iter::adapters::try_process::<core::iter::adapters::by_ref_sized::ByRefSized<core::iter::adapters::map::Map<core::slice::iter::Iter<rustc_middle::ty::VariantDef>, rustc_ty_utils::layout::layout_of_uncached::{closure#13}>>, rustc_index::vec::IndexVec<rustc_abi::layout::ty::FieldIdx, rustc_abi::layout::ty::TyAndLayout<rustc_middle::ty::Ty>>, core::result::Result<core::convert::Infallible, &rustc_middle::ty::layout::LayoutError>, <core::iter::adapters::map::Map<core::slice::iter::Iter<rustc_middle::ty::VariantDef>, rustc_ty_utils::layout::layout_of_uncached::{closure#13}> as core::iter::traits::iterator::Iterator>::try_collect<rustc_index::vec::IndexVec<rustc_abi::layout::ty::VariantIdx, rustc_index::vec::IndexVec<rustc_abi::layout::ty::FieldIdx, rustc_abi::layout::ty::TyAndLayout<rustc_middle::ty::Ty>>>>::{closure#0}, rustc_index::vec::IndexVec<rustc_abi::layout::ty::VariantIdx, rustc_index::vec::IndexVec<rustc_abi::layout::ty::FieldIdx, rustc_abi::layout::ty::TyAndLayout<rustc_middle::ty::Ty>>>>
  11: rustc_ty_utils::layout::layout_of
      [... omitted 2 frames ...]
  12: rustc_middle::query::plumbing::query_get_at::<rustc_query_system::query::caches::DefaultCache<rustc_middle::ty::PseudoCanonicalInput<rustc_middle::ty::Ty>, rustc_middle::query::erase::Erased<[u8; 16]>>>
  13: <rustc_smir::rustc_smir::context::TablesWrapper as stable_mir::compiler_interface::Context>::ty_layout
  14: <stable_mir::ty::Ty>::layout
  15: smir_pretty::printer::collect_ty
             at ./deps/smir_pretty/src/printer.rs:477:65
  16: smir_pretty::printer::collect_vec_tys::{{closure}}
             at ./deps/smir_pretty/src/printer.rs:458:35
  17: core::iter::traits::iterator::Iterator::for_each::call::{{closure}}
             at ./deps/smir_pretty/deps/rust/src/library/core/src/iter/traits/iterator.rs:797:29
  18: <alloc::vec::into_iter::IntoIter<T,A> as core::iter::traits::iterator::Iterator>::fold
             at ./deps/smir_pretty/deps/rust/src/library/alloc/src/vec/into_iter.rs:318:25
  19: core::iter::traits::iterator::Iterator::for_each
             at ./deps/smir_pretty/deps/rust/src/library/core/src/iter/traits/iterator.rs:800:9
  20: smir_pretty::printer::collect_vec_tys
             at ./deps/smir_pretty/src/printer.rs:458:5
  21: smir_pretty::printer::collect_ty
             at ./deps/smir_pretty/src/printer.rs:494:17
  22: <smir_pretty::printer::InternedValueCollector as stable_mir::mir::visit::MirVisitor>::visit_ty
             at ./deps/smir_pretty/src/printer.rs:559:6
  23: stable_mir::mir::visit::MirVisitor::super_mir_const
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/mir/visit.rs:381:9
  24: <smir_pretty::printer::InternedValueCollector as stable_mir::mir::visit::MirVisitor>::visit_mir_const
             at ./deps/smir_pretty/src/printer.rs:555:5
  25: stable_mir::mir::visit::MirVisitor::super_const_operand
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/mir/visit.rs:376:9
  26: stable_mir::mir::visit::MirVisitor::visit_const_operand
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/mir/visit.rs:112:9
  27: stable_mir::mir::visit::MirVisitor::super_operand
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/mir/visit.rs:359:17
  28: stable_mir::mir::visit::MirVisitor::visit_operand
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/mir/visit.rs:99:9
  29: stable_mir::mir::visit::MirVisitor::super_terminator
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/mir/visit.rs:247:17
  30: <smir_pretty::printer::InternedValueCollector as stable_mir::mir::visit::MirVisitor>::visit_terminator
             at ./deps/smir_pretty/src/printer.rs:525:5
  31: stable_mir::mir::visit::MirVisitor::super_basic_block
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/mir/visit.rs:172:9
  32: stable_mir::mir::visit::MirVisitor::visit_basic_block
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/mir/visit.rs:48:9
  33: stable_mir::mir::visit::MirVisitor::super_body
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/mir/visit.rs:146:13
  34: stable_mir::mir::visit::MirVisitor::visit_body
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/mir/visit.rs:44:9
  35: smir_pretty::printer::collect_interned_values
             at ./deps/smir_pretty/src/printer.rs:578:12
  36: smir_pretty::printer::emit_smir_internal
             at ./deps/smir_pretty/src/printer.rs:702:50
  37: smir_pretty::printer::emit_smir
             at ./deps/smir_pretty/src/printer.rs:748:9
  38: <smir_pretty::driver::StableMirCallbacks as rustc_driver_impl::Callbacks>::after_analysis::{{closure}}
             at ./deps/smir_pretty/src/driver.rs:41:45
  39: rustc_smir::rustc_internal::init::{{closure}}
             at ./deps/smir_pretty/deps/rust/src/compiler/rustc_smir/src/rustc_internal/mod.rs:196:33
  40: scoped_tls::ScopedKey<T>::set
             at /home/jost/.cargo/registry/src/index.crates.io-6f17d22bba15001f/scoped-tls-1.0.1/src/lib.rs:137:9
  41: rustc_smir::rustc_internal::init
             at ./deps/smir_pretty/deps/rust/src/compiler/rustc_smir/src/rustc_internal/mod.rs:196:5
  42: rustc_smir::rustc_internal::run::{{closure}}
             at ./deps/smir_pretty/deps/rust/src/compiler/rustc_smir/src/rustc_internal/mod.rs:227:53
  43: stable_mir::compiler_interface::run::{{closure}}
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/compiler_interface.rs:265:40
  44: scoped_tls::ScopedKey<T>::set
             at /home/jost/.cargo/registry/src/index.crates.io-6f17d22bba15001f/scoped-tls-1.0.1/src/lib.rs:137:9
  45: stable_mir::compiler_interface::run
             at ./deps/smir_pretty/deps/rust/src/compiler/stable_mir/src/compiler_interface.rs:265:9
  46: rustc_smir::rustc_internal::run
             at ./deps/smir_pretty/deps/rust/src/compiler/rustc_smir/src/rustc_internal/mod.rs:227:5
  47: <smir_pretty::driver::StableMirCallbacks as rustc_driver_impl::Callbacks>::after_analysis
             at ./deps/smir_pretty/src/driver.rs:41:17
  48: <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}>
  49: <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, &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}
  50: rustc_interface::passes::create_and_enter_global_ctxt::<core::option::Option<rustc_interface::queries::Linker>, rustc_driver_impl::run_compiler::{closure#0}::{closure#2}>
  51: <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}, ()>
  52: 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}>

[jberthold]

Also see Stephen's comment about this: #19 (comment)