reject deref'ing Box deeper in const-eval interpreter #98510

RalfJung · 2022-06-25T23:27:04Z

#95576 added this assertion in deref_operand, but I think it should be in ref_to_mplace (which is the lower-level primitive, i.e., this means it gets checked strictly more often).

r? @oli-obk

rust-highfive · 2022-06-25T23:27:07Z

Some changes occured to the CTFE / Miri engine

cc @rust-lang/miri

RalfJung · 2022-06-25T23:50:59Z

Ah well, I guess not. I just give up on supporting non-ZST allocators in Miri for now. If we want to avoid an endless pile of hacks, this feature needs to go back to the drawing board.

rust-log-analyzer · 2022-06-25T23:54:17Z

The job x86_64-gnu-llvm-12 failed! Check out the build log: (web) (plain)

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

failures:

---- [ui] src/test/ui/consts/const-eval/ub-ref-ptr.rs stdout ----

error: Error: expected failure status (Some(1)) but received status Some(101).
status: exit status: 101
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/consts/const-eval/ub-ref-ptr.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/consts/const-eval/ub-ref-ptr" "-A" "unused" "-Crpath" "-O" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/consts/const-eval/ub-ref-ptr/auxiliary"
stdout: none
--- stderr -------------------------------
error[E0080]: it is undefined behavior to use this value
   |
   |
LL | const UNALIGNED: &u16 = unsafe { mem::transmute(&[0u8; 4]) };
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered an unaligned reference (required 2 byte alignment but found 1)
   |
   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
   = note: the raw bytes of the constant (size: 8, align: 8) {
Some tests failed in compiletest suite=ui mode=ui host=x86_64-unknown-linux-gnu target=x86_64-unknown-linux-gnu
           }

error: internal compiler error: compiler/rustc_const_eval/src/interpret/place.rs:290:13: dereferencing std::boxed::Box<u16>
error: internal compiler error: compiler/rustc_const_eval/src/interpret/place.rs:290:13: dereferencing std::boxed::Box<u16>

thread 'rustc' panicked at 'Box<dyn Any>', /checkout/compiler/rustc_errors/src/lib.rs:1391:9
stack backtrace:
   0:     0x7f58de590a6c - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h8174aee7cbf2a759
   1:     0x7f58de5f7928 - core::fmt::write::h809849e5b526d26f
   2:     0x7f58de5807d1 - std::io::Write::write_fmt::h46e0d972eb5e1408
   3:     0x7f58de593a5e - std::panicking::default_hook::{{closure}}::h587c234b85cc1553
   4:     0x7f58de593749 - std::panicking::default_hook::h64e01dcad16aab76
   5:     0x7f58df0b1134 - rustc_driver[4bf3dc5bca8a0474]::DEFAULT_HOOK::{closure#0}::{closure#0}
   6:     0x7f58de5941c2 - std::panicking::rust_panic_with_hook::h023635d05d31e773
   7:     0x7f58e19b3383 - std[8977bdadcc1f8408]::panicking::begin_panic::<rustc_errors[84accd696cbac90]::ExplicitBug>::{closure#0}
   8:     0x7f58e19b1896 - std[8977bdadcc1f8408]::sys_common::backtrace::__rust_end_short_backtrace::<std[8977bdadcc1f8408]::panicking::begin_panic<rustc_errors[84accd696cbac90]::ExplicitBug>::{closure#0}, !>
   9:     0x7f58df031316 - std[8977bdadcc1f8408]::panicking::begin_panic::<rustc_errors[84accd696cbac90]::ExplicitBug>
  10:     0x7f58e1a47bd6 - std[8977bdadcc1f8408]::panic::panic_any::<rustc_errors[84accd696cbac90]::ExplicitBug>
  11:     0x7f58e1a45516 - <rustc_errors[84accd696cbac90]::HandlerInner>::bug::<&alloc[2024e476fb4ac14a]::string::String>
  12:     0x7f58e1a451d0 - <rustc_errors[84accd696cbac90]::Handler>::bug::<&alloc[2024e476fb4ac14a]::string::String>
  13:     0x7f58e1b21e45 - rustc_middle[e9f05be9410ca4eb]::util::bug::opt_span_bug_fmt::<rustc_span[643b28f7be113f92]::span_encoding::Span>::{closure#0}
  14:     0x7f58e1b2147b - rustc_middle[e9f05be9410ca4eb]::ty::context::tls::with_opt::<rustc_middle[e9f05be9410ca4eb]::util::bug::opt_span_bug_fmt<rustc_span[643b28f7be113f92]::span_encoding::Span>::{closure#0}, ()>::{closure#0}
  15:     0x7f58e1b2142c - rustc_middle[e9f05be9410ca4eb]::ty::context::tls::with_opt::<rustc_middle[e9f05be9410ca4eb]::util::bug::opt_span_bug_fmt<rustc_span[643b28f7be113f92]::span_encoding::Span>::{closure#0}, ()>
  16:     0x7f58e1b21d89 - rustc_middle[e9f05be9410ca4eb]::util::bug::opt_span_bug_fmt::<rustc_span[643b28f7be113f92]::span_encoding::Span>
  17:     0x7f58df034425 - rustc_middle[e9f05be9410ca4eb]::util::bug::bug_fmt
  18:     0x7f58e05cb92d - <rustc_const_eval[c4585237aaf12952]::interpret::eval_context::InterpCx<rustc_const_eval[c4585237aaf12952]::const_eval::machine::CompileTimeInterpreter>>::ref_to_mplace
  19:     0x7f58e0688a66 - <rustc_const_eval[c4585237aaf12952]::interpret::validity::ValidityVisitor<rustc_const_eval[c4585237aaf12952]::const_eval::machine::CompileTimeInterpreter>>::check_safe_pointer
  20:     0x7f58e068b24b - <rustc_const_eval[c4585237aaf12952]::interpret::validity::ValidityVisitor<rustc_const_eval[c4585237aaf12952]::const_eval::machine::CompileTimeInterpreter>>::try_visit_primitive
  21:     0x7f58e05dbd36 - <rustc_const_eval[c4585237aaf12952]::interpret::eval_context::InterpCx<rustc_const_eval[c4585237aaf12952]::const_eval::machine::CompileTimeInterpreter>>::validate_operand_internal
  22:     0x7f58e05fc36b - rustc_const_eval[c4585237aaf12952]::const_eval::eval_queries::eval_to_allocation_raw_provider
  23:     0x7f58e0c6d3c7 - rustc_query_system[b071d76e80e8a73a]::query::plumbing::get_query::<rustc_query_impl[416187f9fb93b47]::queries::eval_to_allocation_raw, rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt>
  24:     0x7f58e07d8f91 - <rustc_query_impl[416187f9fb93b47]::Queries as rustc_middle[e9f05be9410ca4eb]::ty::query::QueryEngine>::eval_to_allocation_raw
  25:     0x7f58e05f915e - rustc_const_eval[c4585237aaf12952]::const_eval::eval_queries::eval_to_const_value_raw_provider
  26:     0x7f58e0c74ada - rustc_query_system[b071d76e80e8a73a]::query::plumbing::get_query::<rustc_query_impl[416187f9fb93b47]::queries::eval_to_const_value_raw, rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt>
  27:     0x7f58e07d9561 - <rustc_query_impl[416187f9fb93b47]::Queries as rustc_middle[e9f05be9410ca4eb]::ty::query::QueryEngine>::eval_to_const_value_raw
  28:     0x7f58e05f8ba3 - rustc_const_eval[c4585237aaf12952]::const_eval::eval_queries::eval_to_const_value_raw_provider
  29:     0x7f58e0c74ada - rustc_query_system[b071d76e80e8a73a]::query::plumbing::get_query::<rustc_query_impl[416187f9fb93b47]::queries::eval_to_const_value_raw, rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt>
  30:     0x7f58e07d9561 - <rustc_query_impl[416187f9fb93b47]::Queries as rustc_middle[e9f05be9410ca4eb]::ty::query::QueryEngine>::eval_to_const_value_raw
  31:     0x7f58e1ad3186 - <rustc_middle[e9f05be9410ca4eb]::ty::query::TyCtxtEnsure>::const_eval_poly
  32:     0x7f58e14f0a78 - <rustc_lint[87a5528bae393346]::BuiltinCombinedModuleLateLintPass as rustc_lint[87a5528bae393346]::passes::LateLintPass>::check_item
  33:     0x7f58e1573b8c - <rustc_lint[87a5528bae393346]::late::LateContextAndPass<rustc_lint[87a5528bae393346]::BuiltinCombinedModuleLateLintPass> as rustc_hir[1c3d27f7e3423356]::intravisit::Visitor>::visit_nested_item
  34:     0x7f58e15a220c - rustc_hir[1c3d27f7e3423356]::intravisit::walk_mod::<rustc_lint[87a5528bae393346]::late::LateContextAndPass<rustc_lint[87a5528bae393346]::BuiltinCombinedModuleLateLintPass>>
  35:     0x7f58e157a12b - rustc_lint[87a5528bae393346]::late::late_lint_mod::<rustc_lint[87a5528bae393346]::BuiltinCombinedModuleLateLintPass>
  36:     0x7f58e14ec60d - rustc_lint[87a5528bae393346]::lint_mod
  37:     0x7f58e0b8319c - rustc_query_system[b071d76e80e8a73a]::query::plumbing::try_execute_query::<rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt, rustc_query_system[b071d76e80e8a73a]::query::caches::DefaultCache<rustc_span[643b28f7be113f92]::def_id::LocalDefId, ()>>
  38:     0x7f58e0c9a024 - rustc_query_system[b071d76e80e8a73a]::query::plumbing::get_query::<rustc_query_impl[416187f9fb93b47]::queries::lint_mod, rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt>
  39:     0x7f58e07cf904 - <rustc_query_impl[416187f9fb93b47]::Queries as rustc_middle[e9f05be9410ca4eb]::ty::query::QueryEngine>::lint_mod
  40:     0x7f58df2672a6 - <rustc_middle[e9f05be9410ca4eb]::hir::map::Map>::for_each_module::<rustc_lint[87a5528bae393346]::late::check_crate<rustc_lint[87a5528bae393346]::BuiltinCombinedLateLintPass, rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}::{closure#2}::{closure#0}::{closure#0}>::{closure#1}::{closure#0}::{closure#0}>
  41:     0x7f58df1f09e2 - <rustc_session[4bf863f84f086a92]::session::Session>::time::<(), rustc_lint[87a5528bae393346]::late::check_crate<rustc_lint[87a5528bae393346]::BuiltinCombinedLateLintPass, rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}::{closure#2}::{closure#0}::{closure#0}>::{closure#1}::{closure#0}>
  42:     0x7f58df1f0a90 - <rustc_session[4bf863f84f086a92]::session::Session>::time::<(), rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}::{closure#2}::{closure#0}>
  43:     0x7f58df1e1c95 - std[8977bdadcc1f8408]::panicking::try::<(), core[6ca84b1c24a80733]::panic::unwind_safe::AssertUnwindSafe<rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}::{closure#2}>>
  44:     0x7f58df26f8ac - <core[6ca84b1c24a80733]::panic::unwind_safe::AssertUnwindSafe<rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}> as core[6ca84b1c24a80733]::ops::function::FnOnce<()>>::call_once
  45:     0x7f58df1e1db6 - std[8977bdadcc1f8408]::panicking::try::<(), core[6ca84b1c24a80733]::panic::unwind_safe::AssertUnwindSafe<rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}>>
  46:     0x7f58df1f254f - <rustc_session[4bf863f84f086a92]::session::Session>::time::<(), rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}>
  47:     0x7f58df1dfbdc - rustc_interface[ab64b9070d359980]::passes::analysis
  48:     0x7f58e0bbb614 - rustc_query_system[b071d76e80e8a73a]::query::plumbing::try_execute_query::<rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt, rustc_query_system[b071d76e80e8a73a]::query::caches::DefaultCache<(), core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>>
  49:     0x7f58e0c99ad2 - rustc_query_system[b071d76e80e8a73a]::query::plumbing::get_query::<rustc_query_impl[416187f9fb93b47]::queries::analysis, rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt>
  50:     0x7f58e07b88ae - <rustc_query_impl[416187f9fb93b47]::Queries as rustc_middle[e9f05be9410ca4eb]::ty::query::QueryEngine>::analysis
  51:     0x7f58df118894 - <rustc_interface[ab64b9070d359980]::passes::QueryContext>::enter::<rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}::{closure#2}::{closure#3}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>
  52:     0x7f58df0ceb85 - <rustc_interface[ab64b9070d359980]::interface::Compiler>::enter::<rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}::{closure#2}, core[6ca84b1c24a80733]::result::Result<core[6ca84b1c24a80733]::option::Option<rustc_interface[ab64b9070d359980]::queries::Linker>, rustc_errors[84accd696cbac90]::ErrorGuaranteed>>
  53:     0x7f58df12613b - rustc_span[643b28f7be113f92]::with_source_map::<core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>, rustc_interface[ab64b9070d359980]::interface::create_compiler_and_run<core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>, rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}>::{closure#1}>
  54:     0x7f58df0cfd21 - <scoped_tls[2eb65e05ba874bad]::ScopedKey<rustc_span[643b28f7be113f92]::SessionGlobals>>::set::<rustc_interface[ab64b9070d359980]::interface::run_compiler<core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>, rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}>::{closure#0}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>
  55:     0x7f58df11b9d9 - std[8977bdadcc1f8408]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[ab64b9070d359980]::util::run_in_thread_pool_with_globals<rustc_interface[ab64b9070d359980]::interface::run_compiler<core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>, rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}>::{closure#0}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>::{closure#0}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>
  56:     0x7f58df11c579 - <<std[8977bdadcc1f8408]::thread::Builder>::spawn_unchecked_<rustc_interface[ab64b9070d359980]::util::run_in_thread_pool_with_globals<rustc_interface[ab64b9070d359980]::interface::run_compiler<core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>, rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}>::{closure#0}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>::{closure#0}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>::{closure#1} as core[6ca84b1c24a80733]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  57:     0x7f58de59f5a3 - std::sys::unix::thread::Thread::new::thread_start::h4ee95bea9fcf8a9f
  58:     0x7f58d8af2609 - start_thread
  59:     0x7f58de405133 - clone
  60:                0x0 - <unknown>
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 1.64.0-nightly (2ab373988 2022-06-25) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z threads=1 -C codegen-units=1 -Z ui-testing -Z deduplicate-diagnostics=no -C prefer-dynamic -C rpath -C debuginfo=0
query stack during panic:
query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `UNALIGNED_BOX`
#1 [eval_to_const_value_raw] simplifying constant for the type system `UNALIGNED_BOX`
#2 [eval_to_const_value_raw] simplifying constant for the type system `UNALIGNED_BOX`
#3 [lint_mod] linting top-level module
#4 [analysis] running analysis passes on this crate
error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0080`.
------------------------------------------
------------------------------------------


---- [ui] src/test/ui/consts/const-eval/ub-wide-ptr.rs stdout ----

error: Error: expected failure status (Some(1)) but received status Some(101).
status: exit status: 101
command: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs" "-Zthreads=1" "--target=x86_64-unknown-linux-gnu" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/consts/const-eval/ub-wide-ptr" "-A" "unused" "-Crpath" "-O" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/consts/const-eval/ub-wide-ptr/auxiliary"
stdout: none
--- stderr -------------------------------
error[E0080]: it is undefined behavior to use this value
   |
   |
LL | const STR_TOO_LONG: &str = unsafe { mem::transmute((&42u8, 999usize)) };
   |
   |
   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
   = note: the raw bytes of the constant (size: 16, align: 8) {
               ╾───────alloc8────────╼ e7 03 00 00 00 00 00 00 │ ╾──────╼........

error[E0080]: it is undefined behavior to use this value
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:39:1
   |
   |
LL | const NESTED_STR_MUCH_TOO_LONG: (&str,) = (unsafe { mem::transmute((&42, usize::MAX)) },);
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .0: encountered invalid reference metadata: slice is bigger than largest supported object
   |
   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
   = note: the raw bytes of the constant (size: 16, align: 8) {
               ╾───────alloc14───────╼ ff ff ff ff ff ff ff ff │ ╾──────╼........

error: any use of this value will cause an error
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:42:1
   |
   |
LL | const STR_LENGTH_PTR: &str = unsafe { mem::transmute((&42u8, &3)) };
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unable to turn pointer into raw bytes
   |
   = note: `#[deny(const_err)]` on by default
   = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800>

error: any use of this value will cause an error
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:46:1
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:46:1
   |
LL | const MY_STR_LENGTH_PTR: &MyStr = unsafe { mem::transmute((&42u8, &3)) };
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unable to turn pointer into raw bytes
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800>

error[E0080]: it is undefined behavior to use this value
error[E0080]: it is undefined behavior to use this value
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:49:1
   |
LL | const MY_STR_MUCH_TOO_LONG: &MyStr = unsafe { mem::transmute((&42u8, usize::MAX)) };
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered invalid reference metadata: slice is bigger than largest supported object
   |
   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
   = note: the raw bytes of the constant (size: 16, align: 8) {
               ╾───────alloc34───────╼ ff ff ff ff ff ff ff ff │ ╾──────╼........

error[E0080]: it is undefined behavior to use this value
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:53:1
   |
   |
LL | const STR_NO_INIT: &str = unsafe { mem::transmute::<&[_], _>(&[MaybeUninit::<u8> { uninit: () }]) };
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .<deref>: encountered uninitialized data in `str`
   |
   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
   = note: the raw bytes of the constant (size: 16, align: 8) {
           }

error[E0080]: it is undefined behavior to use this value
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:56:1
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:56:1
   |
LL | const MYSTR_NO_INIT: &MyStr = unsafe { mem::transmute::<&[_], _>(&[MaybeUninit::<u8> { uninit: () }]) };
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed at .<deref>.0: encountered uninitialized data in `str`
   |
   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
   = note: the raw bytes of the constant (size: 16, align: 8) {
           }

error[E0080]: it is undefined behavior to use this value
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:63:1
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:63:1
   |
LL | / const SLICE_LENGTH_UNINIT: &[u8] = unsafe {
LL | | //~^ ERROR it is undefined behavior to use this value
LL | |     let uninit_len = MaybeUninit::<usize> { uninit: () };
LL | |     mem::transmute((42, uninit_len))
LL | | };
   | |__^ type validation failed: encountered uninitialized reference
   |
   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
   = note: the raw bytes of the constant (size: 16, align: 8) {
               __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ │ ░░░░░░░░░░░░░░░░

error[E0080]: it is undefined behavior to use this value
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:69:1
   |
   |
LL | const SLICE_TOO_LONG: &[u8] = unsafe { mem::transmute((&42u8, 999usize)) };
   |
   |
   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
   = note: the raw bytes of the constant (size: 16, align: 8) {
               ╾───────alloc62───────╼ e7 03 00 00 00 00 00 00 │ ╾──────╼........

error[E0080]: it is undefined behavior to use this value
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:72:1
   |
   |
LL | const SLICE_TOO_LONG_OVERFLOW: &[u32] = unsafe { mem::transmute((&42u32, isize::MAX)) };
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type validation failed: encountered invalid reference metadata: slice is bigger than largest supported object
   |
   = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
   = note: the raw bytes of the constant (size: 16, align: 8) {
               ╾───────alloc70───────╼ ff ff ff ff ff ff ff 7f │ ╾──────╼........

error: any use of this value will cause an error
  --> /checkout/src/test/ui/consts/const-eval/ub-wide-ptr.rs:75:1
   |
   |
LL | const SLICE_LENGTH_PTR: &[u8] = unsafe { mem::transmute((&42u8, &3)) };
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unable to turn pointer into raw bytes
   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
   = note: for more information, see issue #71800 <https://github.com/rust-lang/rust/issues/71800>

error: internal compiler error: compiler/rustc_const_eval/src/interpret/place.rs:290:13: dereferencing std::boxed::Box<[u8]>
error: internal compiler error: compiler/rustc_const_eval/src/interpret/place.rs:290:13: dereferencing std::boxed::Box<[u8]>

thread 'rustc' panicked at 'Box<dyn Any>', /checkout/compiler/rustc_errors/src/lib.rs:1391:9
stack backtrace:
   0:     0x7ff3cd2c1a6c - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h8174aee7cbf2a759
   1:     0x7ff3cd328928 - core::fmt::write::h809849e5b526d26f
   2:     0x7ff3cd2b17d1 - std::io::Write::write_fmt::h46e0d972eb5e1408
   3:     0x7ff3cd2c4a5e - std::panicking::default_hook::{{closure}}::h587c234b85cc1553
   4:     0x7ff3cd2c4749 - std::panicking::default_hook::h64e01dcad16aab76
   5:     0x7ff3cdde2134 - rustc_driver[4bf3dc5bca8a0474]::DEFAULT_HOOK::{closure#0}::{closure#0}
   6:     0x7ff3cd2c51c2 - std::panicking::rust_panic_with_hook::h023635d05d31e773
   7:     0x7ff3d06e4383 - std[8977bdadcc1f8408]::panicking::begin_panic::<rustc_errors[84accd696cbac90]::ExplicitBug>::{closure#0}
   8:     0x7ff3d06e2896 - std[8977bdadcc1f8408]::sys_common::backtrace::__rust_end_short_backtrace::<std[8977bdadcc1f8408]::panicking::begin_panic<rustc_errors[84accd696cbac90]::ExplicitBug>::{closure#0}, !>
   9:     0x7ff3cdd62316 - std[8977bdadcc1f8408]::panicking::begin_panic::<rustc_errors[84accd696cbac90]::ExplicitBug>
  10:     0x7ff3d0778bd6 - std[8977bdadcc1f8408]::panic::panic_any::<rustc_errors[84accd696cbac90]::ExplicitBug>
  11:     0x7ff3d0776516 - <rustc_errors[84accd696cbac90]::HandlerInner>::bug::<&alloc[2024e476fb4ac14a]::string::String>
  12:     0x7ff3d07761d0 - <rustc_errors[84accd696cbac90]::Handler>::bug::<&alloc[2024e476fb4ac14a]::string::String>
  13:     0x7ff3d0852e45 - rustc_middle[e9f05be9410ca4eb]::util::bug::opt_span_bug_fmt::<rustc_span[643b28f7be113f92]::span_encoding::Span>::{closure#0}
  14:     0x7ff3d085247b - rustc_middle[e9f05be9410ca4eb]::ty::context::tls::with_opt::<rustc_middle[e9f05be9410ca4eb]::util::bug::opt_span_bug_fmt<rustc_span[643b28f7be113f92]::span_encoding::Span>::{closure#0}, ()>::{closure#0}
  15:     0x7ff3d085242c - rustc_middle[e9f05be9410ca4eb]::ty::context::tls::with_opt::<rustc_middle[e9f05be9410ca4eb]::util::bug::opt_span_bug_fmt<rustc_span[643b28f7be113f92]::span_encoding::Span>::{closure#0}, ()>
  16:     0x7ff3d0852d89 - rustc_middle[e9f05be9410ca4eb]::util::bug::opt_span_bug_fmt::<rustc_span[643b28f7be113f92]::span_encoding::Span>
  17:     0x7ff3cdd65425 - rustc_middle[e9f05be9410ca4eb]::util::bug::bug_fmt
  18:     0x7ff3cf2fc92d - <rustc_const_eval[c4585237aaf12952]::interpret::eval_context::InterpCx<rustc_const_eval[c4585237aaf12952]::const_eval::machine::CompileTimeInterpreter>>::ref_to_mplace
  19:     0x7ff3cf3b9a66 - <rustc_const_eval[c4585237aaf12952]::interpret::validity::ValidityVisitor<rustc_const_eval[c4585237aaf12952]::const_eval::machine::CompileTimeInterpreter>>::check_safe_pointer
  20:     0x7ff3cf3bc24b - <rustc_const_eval[c4585237aaf12952]::interpret::validity::ValidityVisitor<rustc_const_eval[c4585237aaf12952]::const_eval::machine::CompileTimeInterpreter>>::try_visit_primitive
  21:     0x7ff3cf30cd36 - <rustc_const_eval[c4585237aaf12952]::interpret::eval_context::InterpCx<rustc_const_eval[c4585237aaf12952]::const_eval::machine::CompileTimeInterpreter>>::validate_operand_internal
  22:     0x7ff3cf32d36b - rustc_const_eval[c4585237aaf12952]::const_eval::eval_queries::eval_to_allocation_raw_provider
  23:     0x7ff3cf99e3c7 - rustc_query_system[b071d76e80e8a73a]::query::plumbing::get_query::<rustc_query_impl[416187f9fb93b47]::queries::eval_to_allocation_raw, rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt>
  24:     0x7ff3cf509f91 - <rustc_query_impl[416187f9fb93b47]::Queries as rustc_middle[e9f05be9410ca4eb]::ty::query::QueryEngine>::eval_to_allocation_raw
  25:     0x7ff3cf32a15e - rustc_const_eval[c4585237aaf12952]::const_eval::eval_queries::eval_to_const_value_raw_provider
  26:     0x7ff3cf9a5ada - rustc_query_system[b071d76e80e8a73a]::query::plumbing::get_query::<rustc_query_impl[416187f9fb93b47]::queries::eval_to_const_value_raw, rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt>
  27:     0x7ff3cf50a561 - <rustc_query_impl[416187f9fb93b47]::Queries as rustc_middle[e9f05be9410ca4eb]::ty::query::QueryEngine>::eval_to_const_value_raw
  28:     0x7ff3cf329ba3 - rustc_const_eval[c4585237aaf12952]::const_eval::eval_queries::eval_to_const_value_raw_provider
  29:     0x7ff3cf9a5ada - rustc_query_system[b071d76e80e8a73a]::query::plumbing::get_query::<rustc_query_impl[416187f9fb93b47]::queries::eval_to_const_value_raw, rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt>
  30:     0x7ff3cf50a561 - <rustc_query_impl[416187f9fb93b47]::Queries as rustc_middle[e9f05be9410ca4eb]::ty::query::QueryEngine>::eval_to_const_value_raw
  31:     0x7ff3d0804186 - <rustc_middle[e9f05be9410ca4eb]::ty::query::TyCtxtEnsure>::const_eval_poly
  32:     0x7ff3d0221a78 - <rustc_lint[87a5528bae393346]::BuiltinCombinedModuleLateLintPass as rustc_lint[87a5528bae393346]::passes::LateLintPass>::check_item
  33:     0x7ff3d02a4b8c - <rustc_lint[87a5528bae393346]::late::LateContextAndPass<rustc_lint[87a5528bae393346]::BuiltinCombinedModuleLateLintPass> as rustc_hir[1c3d27f7e3423356]::intravisit::Visitor>::visit_nested_item
  34:     0x7ff3d02d320c - rustc_hir[1c3d27f7e3423356]::intravisit::walk_mod::<rustc_lint[87a5528bae393346]::late::LateContextAndPass<rustc_lint[87a5528bae393346]::BuiltinCombinedModuleLateLintPass>>
  35:     0x7ff3d02ab12b - rustc_lint[87a5528bae393346]::late::late_lint_mod::<rustc_lint[87a5528bae393346]::BuiltinCombinedModuleLateLintPass>
  36:     0x7ff3d021d60d - rustc_lint[87a5528bae393346]::lint_mod
  37:     0x7ff3cf8b419c - rustc_query_system[b071d76e80e8a73a]::query::plumbing::try_execute_query::<rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt, rustc_query_system[b071d76e80e8a73a]::query::caches::DefaultCache<rustc_span[643b28f7be113f92]::def_id::LocalDefId, ()>>
  38:     0x7ff3cf9cb024 - rustc_query_system[b071d76e80e8a73a]::query::plumbing::get_query::<rustc_query_impl[416187f9fb93b47]::queries::lint_mod, rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt>
  39:     0x7ff3cf500904 - <rustc_query_impl[416187f9fb93b47]::Queries as rustc_middle[e9f05be9410ca4eb]::ty::query::QueryEngine>::lint_mod
  40:     0x7ff3cdf982a6 - <rustc_middle[e9f05be9410ca4eb]::hir::map::Map>::for_each_module::<rustc_lint[87a5528bae393346]::late::check_crate<rustc_lint[87a5528bae393346]::BuiltinCombinedLateLintPass, rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}::{closure#2}::{closure#0}::{closure#0}>::{closure#1}::{closure#0}::{closure#0}>
  41:     0x7ff3cdf219e2 - <rustc_session[4bf863f84f086a92]::session::Session>::time::<(), rustc_lint[87a5528bae393346]::late::check_crate<rustc_lint[87a5528bae393346]::BuiltinCombinedLateLintPass, rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}::{closure#2}::{closure#0}::{closure#0}>::{closure#1}::{closure#0}>
  42:     0x7ff3cdf21a90 - <rustc_session[4bf863f84f086a92]::session::Session>::time::<(), rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}::{closure#2}::{closure#0}>
  43:     0x7ff3cdf12c95 - std[8977bdadcc1f8408]::panicking::try::<(), core[6ca84b1c24a80733]::panic::unwind_safe::AssertUnwindSafe<rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}::{closure#2}>>
  44:     0x7ff3cdfa08ac - <core[6ca84b1c24a80733]::panic::unwind_safe::AssertUnwindSafe<rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}> as core[6ca84b1c24a80733]::ops::function::FnOnce<()>>::call_once
  45:     0x7ff3cdf12db6 - std[8977bdadcc1f8408]::panicking::try::<(), core[6ca84b1c24a80733]::panic::unwind_safe::AssertUnwindSafe<rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}::{closure#1}>>
  46:     0x7ff3cdf2354f - <rustc_session[4bf863f84f086a92]::session::Session>::time::<(), rustc_interface[ab64b9070d359980]::passes::analysis::{closure#5}>
  47:     0x7ff3cdf10bdc - rustc_interface[ab64b9070d359980]::passes::analysis
  48:     0x7ff3cf8ec614 - rustc_query_system[b071d76e80e8a73a]::query::plumbing::try_execute_query::<rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt, rustc_query_system[b071d76e80e8a73a]::query::caches::DefaultCache<(), core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>>
  49:     0x7ff3cf9caad2 - rustc_query_system[b071d76e80e8a73a]::query::plumbing::get_query::<rustc_query_impl[416187f9fb93b47]::queries::analysis, rustc_query_impl[416187f9fb93b47]::plumbing::QueryCtxt>
  50:     0x7ff3cf4e98ae - <rustc_query_impl[416187f9fb93b47]::Queries as rustc_middle[e9f05be9410ca4eb]::ty::query::QueryEngine>::analysis
  51:     0x7ff3cde49894 - <rustc_interface[ab64b9070d359980]::passes::QueryContext>::enter::<rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}::{closure#2}::{closure#3}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>
  52:     0x7ff3cddffb85 - <rustc_interface[ab64b9070d359980]::interface::Compiler>::enter::<rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}::{closure#2}, core[6ca84b1c24a80733]::result::Result<core[6ca84b1c24a80733]::option::Option<rustc_interface[ab64b9070d359980]::queries::Linker>, rustc_errors[84accd696cbac90]::ErrorGuaranteed>>
  53:     0x7ff3cde5713b - rustc_span[643b28f7be113f92]::with_source_map::<core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>, rustc_interface[ab64b9070d359980]::interface::create_compiler_and_run<core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>, rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}>::{closure#1}>
  54:     0x7ff3cde00d21 - <scoped_tls[2eb65e05ba874bad]::ScopedKey<rustc_span[643b28f7be113f92]::SessionGlobals>>::set::<rustc_interface[ab64b9070d359980]::interface::run_compiler<core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>, rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}>::{closure#0}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>
  55:     0x7ff3cde4c9d9 - std[8977bdadcc1f8408]::sys_common::backtrace::__rust_begin_short_backtrace::<rustc_interface[ab64b9070d359980]::util::run_in_thread_pool_with_globals<rustc_interface[ab64b9070d359980]::interface::run_compiler<core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>, rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}>::{closure#0}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>::{closure#0}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>
  56:     0x7ff3cde4d579 - <<std[8977bdadcc1f8408]::thread::Builder>::spawn_unchecked_<rustc_interface[ab64b9070d359980]::util::run_in_thread_pool_with_globals<rustc_interface[ab64b9070d359980]::interface::run_compiler<core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>, rustc_driver[4bf3dc5bca8a0474]::run_compiler::{closure#1}>::{closure#0}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>::{closure#0}, core[6ca84b1c24a80733]::result::Result<(), rustc_errors[84accd696cbac90]::ErrorGuaranteed>>::{closure#1} as core[6ca84b1c24a80733]::ops::function::FnOnce<()>>::call_once::{shim:vtable#0}
  57:     0x7ff3cd2d05a3 - std::sys::unix::thread::Thread::new::thread_start::h4ee95bea9fcf8a9f
  58:     0x7ff3c7823609 - start_thread
  59:     0x7ff3cd136133 - clone
  60:                0x0 - <unknown>
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 1.64.0-nightly (2ab373988 2022-06-25) running on x86_64-unknown-linux-gnu

note: compiler flags: -Z threads=1 -C codegen-units=1 -Z ui-testing -Z deduplicate-diagnostics=no -C prefer-dynamic -C rpath -C debuginfo=0
query stack during panic:
query stack during panic:
#0 [eval_to_allocation_raw] const-evaluating + checking `SLICE_TOO_LONG_BOX`
#1 [eval_to_const_value_raw] simplifying constant for the type system `SLICE_TOO_LONG_BOX`
#2 [eval_to_const_value_raw] simplifying constant for the type system `SLICE_TOO_LONG_BOX`
#3 [lint_mod] linting top-level module
#4 [analysis] running analysis passes on this crate
error: aborting due to 12 previous errors

For more information about this error, try `rustc --explain E0080`.
------------------------------------------

…ial, r=RalfJung Fix box with custom allocator in miri This should fix the failures in rust-lang/miri#2072 and rust-lang#98510. cc `@RalfJung`

…ial, r=RalfJung Fix box with custom allocator in miri This should fix the failures in rust-lang/miri#2072 and rust-lang#98510. cc ``@RalfJung``

…ial, r=RalfJung Fix box with custom allocator in miri This should fix the failures in rust-lang/miri#2072 and rust-lang#98510. cc ```@RalfJung```

reject deref'ing Box deeper in const-eval interpreter

4aecee5

rust-highfive assigned oli-obk Jun 25, 2022

rustbot added the T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. label Jun 25, 2022

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jun 25, 2022

RalfJung mentioned this pull request Jun 25, 2022

Boxes with custom allocators break several underlying assumptions in Miri (and MIR more broadly) #95453

Open

RalfJung closed this Jun 25, 2022

RalfJung deleted the no-deref-box branch June 25, 2022 23:51

beepster4096 mentioned this pull request Jun 26, 2022

Fix box with custom allocator in miri #98554

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reject deref'ing Box deeper in const-eval interpreter #98510

reject deref'ing Box deeper in const-eval interpreter #98510

RalfJung commented Jun 25, 2022

rust-highfive commented Jun 25, 2022

RalfJung commented Jun 25, 2022 •

edited

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rust-log-analyzer commented Jun 25, 2022

reject deref'ing Box deeper in const-eval interpreter #98510

reject deref'ing Box deeper in const-eval interpreter #98510

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RalfJung commented Jun 25, 2022

rust-highfive commented Jun 25, 2022

RalfJung commented Jun 25, 2022 • edited Loading

rust-log-analyzer commented Jun 25, 2022

RalfJung commented Jun 25, 2022 •

edited

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