error on alignments greater than `isize::MAX`

[asquared31415]

trafficstars

Fixes #131122

On zulip someone had a concern that it was legal to create a type with alignment isize::MAX + 1, but I do not believe this should be allowed for repr(align), as repr(align) also increases the size of the type, and that would be larger than the maximum allowed size of objects.

(cc @workingjubilee #131276)

[rustbot]

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[rust-log-analyzer]

The job x86_64-gnu-llvm-18 failed! Check out the build log: (web) (plain)

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

------
 > importing cache manifest from ghcr.io/rust-lang/rust-ci-cache:c32c805632780b5c1de330e3f44561b336c2efe163bc0990acb392390157a8e1d9f855d75914a239aa40c49d77f4a837247d05d2f8d46f554b98e1f46712a3e3:
------
##[endgroup]
Setting extra environment values for docker:  --env ENABLE_GCC_CODEGEN=1 --env GCC_EXEC_PREFIX=/usr/lib/gcc/
[CI_JOB_NAME=x86_64-gnu-llvm-18]
debug: `DISABLE_CI_RUSTC_IF_INCOMPATIBLE` configured.
---
sccache: Starting the server...
##[group]Configure the build
configure: processing command line
configure: 
configure: build.configure-args := ['--build=x86_64-unknown-linux-gnu', '--llvm-root=/usr/lib/llvm-18', '--enable-llvm-link-shared', '--set', 'rust.randomize-layout=true', '--set', 'rust.thin-lto-import-instr-limit=10', '--set', 'change-id=99999999', '--enable-verbose-configure', '--enable-sccache', '--disable-manage-submodules', '--enable-locked-deps', '--enable-cargo-native-static', '--set', 'rust.codegen-units-std=1', '--set', 'dist.compression-profile=balanced', '--dist-compression-formats=xz', '--set', 'rust.lld=false', '--disable-dist-src', '--release-channel=nightly', '--enable-debug-assertions', '--enable-overflow-checks', '--enable-llvm-assertions', '--set', 'rust.verify-llvm-ir', '--set', 'rust.codegen-backends=llvm,cranelift,gcc', '--set', 'llvm.static-libstdcpp', '--enable-new-symbol-mangling']
configure: target.x86_64-unknown-linux-gnu.llvm-config := /usr/lib/llvm-18/bin/llvm-config
configure: llvm.link-shared     := True
configure: rust.randomize-layout := True
configure: rust.thin-lto-import-instr-limit := 10
---
failures:

---- [ui] tests/ui/attributes/arg-error-issue-121425.rs stdout ----

error: Error: expected failure status (Some(1)) but received status Some(101).
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/attributes/arg-error-issue-121425.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/x86_64-unknown-linux-gnu/stage2" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/attributes/arg-error-issue-121425" "-A" "unused" "-A" "internal_features" "-Crpath" "-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/attributes/arg-error-issue-121425/auxiliary" "-Zdeduplicate-diagnostics=yes"
--- stderr -------------------------------
--- stderr -------------------------------
error[E0693]: incorrect `repr(align)` attribute format: `align` expects a literal integer as argument
   |
   |
LL | #[repr(align(N))]


error[E0589]: invalid `repr(align)` attribute: not an unsuffixed integer
   |
   |
LL | #[repr(align('a'))]


error[E0589]: invalid `repr(align)` attribute: not an unsuffixed integer
   |
   |
LL | #[repr(align("str"))]


error[E0693]: incorrect `repr(align)` attribute format: `align` takes exactly one argument in parentheses
   |
   |
LL | #[repr(align())]


error[E0552]: incorrect `repr(packed)` attribute format: `packed` expects a literal integer as argument
   |
   |
LL | #[repr(packed(P))]


error[E0552]: incorrect `repr(packed)` attribute format: `packed` takes exactly one parenthesized argument, or no parentheses at all
   |
LL | #[repr(packed())]
   |        ^^^^^^^^

---
   1: core::panicking::panic_fmt
   2: core::panicking::panic
   3: core::option::unwrap_failed
   4: <rustc_passes::check_attr::CheckAttrVisitor>::check_attributes
   5: <rustc_passes::check_attr::CheckAttrVisitor as rustc_hir::intravisit::Visitor>::visit_item
   6: <rustc_middle::hir::map::Map>::visit_item_likes_in_module::<rustc_passes::check_attr::CheckAttrVisitor>
   7: rustc_passes::check_attr::check_mod_attrs
      [... omitted 2 frames ...]
   8: <rustc_middle::hir::map::Map>::par_for_each_module::<rustc_interface::passes::run_required_analyses::{closure#0}::{closure#1}::{closure#0}::{closure#4}::{closure#0}>::{closure#0}
   9: <rustc_data_structures::sync::parallel::ParallelGuard>::run::<(), rustc_interface::passes::run_required_analyses::{closure#0}::{closure#0}::{closure#1}>
  10: <rustc_session::session::Session>::time::<(), rustc_interface::passes::run_required_analyses::{closure#0}>
  11: rustc_interface::passes::analysis
      [... omitted 2 frames ...]
  13: <rustc_interface::interface::Compiler>::enter::<rustc_driver_impl::run_compiler::{closure#0}::{closure#1}, core::result::Result<core::option::Option<rustc_interface::queries::Linker>, rustc_span::ErrorGuaranteed>>
  14: <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<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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

note: rustc 1.83.0-nightly (0faf11d8f 2024-10-12) running on x86_64-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 -Z deduplicate-diagnostics=yes
query stack during panic:
#0 [check_mod_attrs] checking attributes in top-level module
#1 [analysis] running analysis passes on this crate
end of query stack
---


---- [ui] tests/ui/attributes/nonterminal-expansion.rs stdout ----

error: Error: expected failure status (Some(1)) but received status Some(101).
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/attributes/nonterminal-expansion.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/x86_64-unknown-linux-gnu/stage2" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/attributes/nonterminal-expansion" "-A" "unused" "-A" "internal_features" "-Crpath" "-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/attributes/nonterminal-expansion/auxiliary" "-Zdeduplicate-diagnostics=yes"
--- stderr -------------------------------
--- stderr -------------------------------
error: expected unsuffixed literal, found `n!()`
   |
   |
LL |         #[repr(align($n))]
...
...
LL | pass_nonterminal!(n!());
   |
   = note: this error originates in the macro `pass_nonterminal` (in Nightly builds, run with -Z macro-backtrace for more info)

thread 'rustc' panicked at compiler/rustc_passes/src/check_attr.rs:1800:64:
thread 'rustc' panicked at compiler/rustc_passes/src/check_attr.rs:1800:64:
called `Option::unwrap()` on a `None` value
stack backtrace:
   0: rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::panicking::panic
   3: core::option::unwrap_failed
   4: <rustc_passes::check_attr::CheckAttrVisitor>::check_attributes
   5: <rustc_passes::check_attr::CheckAttrVisitor as rustc_hir::intravisit::Visitor>::visit_item
   6: <rustc_middle::hir::map::Map>::visit_item_likes_in_module::<rustc_passes::check_attr::CheckAttrVisitor>
   7: rustc_passes::check_attr::check_mod_attrs
      [... omitted 2 frames ...]
   8: <rustc_middle::hir::map::Map>::par_for_each_module::<rustc_interface::passes::run_required_analyses::{closure#0}::{closure#1}::{closure#0}::{closure#4}::{closure#0}>::{closure#0}
   9: <rustc_data_structures::sync::parallel::ParallelGuard>::run::<(), rustc_interface::passes::run_required_analyses::{closure#0}::{closure#0}::{closure#1}>
  10: <rustc_session::session::Session>::time::<(), rustc_interface::passes::run_required_analyses::{closure#0}>
  11: rustc_interface::passes::analysis
      [... omitted 2 frames ...]
  13: <rustc_interface::interface::Compiler>::enter::<rustc_driver_impl::run_compiler::{closure#0}::{closure#1}, core::result::Result<core::option::Option<rustc_interface::queries::Linker>, rustc_span::ErrorGuaranteed>>
  14: <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<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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

note: rustc 1.83.0-nightly (0faf11d8f 2024-10-12) running on x86_64-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 -Z deduplicate-diagnostics=yes
query stack during panic:
#0 [check_mod_attrs] checking attributes in top-level module
#1 [analysis] running analysis passes on this crate
end of query stack
end of query stack
error: aborting due to 1 previous error
------------------------------------------


---- [ui] tests/ui/repr/malformed-repr-hints.rs stdout ----

error: Error: expected failure status (Some(1)) but received status Some(101).
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/repr/malformed-repr-hints.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/x86_64-unknown-linux-gnu/stage2" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/repr/malformed-repr-hints" "-A" "unused" "-A" "internal_features" "-Crpath" "-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/repr/malformed-repr-hints/auxiliary" "-Zdeduplicate-diagnostics=yes"
--- stderr -------------------------------
--- stderr -------------------------------
error[E0552]: incorrect `repr(packed)` attribute format: `packed` takes exactly one parenthesized argument, or no parentheses at all
   |
LL | #[repr(packed())]
   |        ^^^^^^^^


error[E0589]: invalid `repr(align)` attribute: `align` needs an argument
   |
   |
LL | #[repr(align)]
   |        ^^^^^ help: supply an argument here: `align(...)`

error[E0693]: incorrect `repr(align)` attribute format: `align` takes exactly one argument in parentheses
   |
   |
LL | #[repr(align(2, 4))]


error[E0693]: incorrect `repr(align)` attribute format: `align` takes exactly one argument in parentheses
   |
   |
LL | #[repr(align())]

error[E0552]: invalid representation hint: `Rust` does not take a parenthesized argument list
##[error]  --> /checkout/tests/ui/repr/malformed-repr-hints.rs:23:8
   |
   |
LL | #[repr(Rust(u8))]

error[E0552]: invalid representation hint: `Rust` does not take a parenthesized argument list
##[error]  --> /checkout/tests/ui/repr/malformed-repr-hints.rs:25:8
   |
   |
LL | #[repr(Rust(0))]

error[E0552]: invalid representation hint: `Rust` does not take a value
##[error]  --> /checkout/tests/ui/repr/malformed-repr-hints.rs:27:8
   |
   |
LL | #[repr(Rust = 0)]

error[E0552]: invalid representation hint: `i8` does not take a parenthesized argument list
##[error]  --> /checkout/tests/ui/repr/malformed-repr-hints.rs:31:8
   |
   |
LL | #[repr(i8())]


error[E0552]: invalid representation hint: `u32` does not take a parenthesized argument list
   |
   |
LL | #[repr(u32(42))]

error[E0552]: invalid representation hint: `i64` does not take a value
##[error]  --> /checkout/tests/ui/repr/malformed-repr-hints.rs:39:8
   |
   |
LL | #[repr(i64 = 2)]

thread 'rustc' panicked at compiler/rustc_passes/src/check_attr.rs:1800:64:
called `Option::unwrap()` on a `None` value
stack backtrace:
stack backtrace:
   0: rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::panicking::panic
   3: core::option::unwrap_failed
   4: <rustc_passes::check_attr::CheckAttrVisitor>::check_attributes
   5: <rustc_passes::check_attr::CheckAttrVisitor as rustc_hir::intravisit::Visitor>::visit_item
   6: <rustc_middle::hir::map::Map>::visit_item_likes_in_module::<rustc_passes::check_attr::CheckAttrVisitor>
   7: rustc_passes::check_attr::check_mod_attrs
      [... omitted 2 frames ...]
   8: <rustc_middle::hir::map::Map>::par_for_each_module::<rustc_interface::passes::run_required_analyses::{closure#0}::{closure#1}::{closure#0}::{closure#4}::{closure#0}>::{closure#0}
   9: <rustc_data_structures::sync::parallel::ParallelGuard>::run::<(), rustc_interface::passes::run_required_analyses::{closure#0}::{closure#0}::{closure#1}>
  10: <rustc_session::session::Session>::time::<(), rustc_interface::passes::run_required_analyses::{closure#0}>
  11: rustc_interface::passes::analysis
      [... omitted 2 frames ...]
  13: <rustc_interface::interface::Compiler>::enter::<rustc_driver_impl::run_compiler::{closure#0}::{closure#1}, core::result::Result<core::option::Option<rustc_interface::queries::Linker>, rustc_span::ErrorGuaranteed>>
  14: <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<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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

note: rustc 1.83.0-nightly (0faf11d8f 2024-10-12) running on x86_64-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 -Z deduplicate-diagnostics=yes
query stack during panic:
#0 [check_mod_attrs] checking attributes in top-level module
#1 [analysis] running analysis passes on this crate
end of query stack
---


---- [ui] tests/ui/repr/repr-align-assign.rs stdout ----

error: Error: expected failure status (Some(1)) but received status Some(101).
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/repr/repr-align-assign.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/x86_64-unknown-linux-gnu/stage2" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/repr/repr-align-assign" "-A" "unused" "-A" "internal_features" "-Crpath" "-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/repr/repr-align-assign/auxiliary"
--- stderr -------------------------------
--- stderr -------------------------------
error[E0693]: incorrect `repr(align)` attribute format
   |
   |
LL | #[repr(align=8)] //~ ERROR incorrect `repr(align)` attribute format
   |        ^^^^^^^ help: use parentheses instead: `align(8)`

error[E0693]: incorrect `repr(align)` attribute format
   |
   |
LL | #[repr(align="8")] //~ ERROR incorrect `repr(align)` attribute format
   |        ^^^^^^^^^ help: use parentheses instead: `align(8)`
thread 'rustc' panicked at compiler/rustc_passes/src/check_attr.rs:1800:64:
called `Option::unwrap()` on a `None` value
stack backtrace:
   0: rust_begin_unwind
   0: rust_begin_unwind
   1: core::panicking::panic_fmt
   2: core::panicking::panic
   3: core::option::unwrap_failed
   4: <rustc_passes::check_attr::CheckAttrVisitor>::check_attributes
   5: <rustc_passes::check_attr::CheckAttrVisitor as rustc_hir::intravisit::Visitor>::visit_item
   6: <rustc_middle::hir::map::Map>::visit_item_likes_in_module::<rustc_passes::check_attr::CheckAttrVisitor>
   7: rustc_passes::check_attr::check_mod_attrs
      [... omitted 2 frames ...]
   8: <rustc_middle::hir::map::Map>::par_for_each_module::<rustc_interface::passes::run_required_analyses::{closure#0}::{closure#1}::{closure#0}::{closure#4}::{closure#0}>::{closure#0}
   9: <rustc_data_structures::sync::parallel::ParallelGuard>::run::<(), rustc_interface::passes::run_required_analyses::{closure#0}::{closure#0}::{closure#1}>
  10: <rustc_session::session::Session>::time::<(), rustc_interface::passes::run_required_analyses::{closure#0}>
  11: rustc_interface::passes::analysis
      [... omitted 2 frames ...]
  13: <rustc_interface::interface::Compiler>::enter::<rustc_driver_impl::run_compiler::{closure#0}::{closure#1}, core::result::Result<core::option::Option<rustc_interface::queries::Linker>, rustc_span::ErrorGuaranteed>>
  14: <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<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

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

note: rustc 1.83.0-nightly (0faf11d8f 2024-10-12) running on x86_64-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
query stack during panic:
#0 [check_mod_attrs] checking attributes in top-level module
#1 [analysis] running analysis passes on this crate
end of query stack
---


---- [ui] tests/ui/repr/repr-align.rs stdout ----

error: Error: expected failure status (Some(1)) but received status Some(101).
status: exit status: 101
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/repr/repr-align.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/x86_64-unknown-linux-gnu/stage2" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/repr/repr-align" "-A" "unused" "-A" "internal_features" "-Crpath" "-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/repr/repr-align/auxiliary"
--- stderr -------------------------------
--- stderr -------------------------------
error[E0589]: invalid `repr(align)` attribute: not an unsuffixed integer
   |
   |
LL | #[repr(align(16.0))] //~ ERROR: invalid `repr(align)` attribute: not an unsuffixed integer


error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(15))] //~ ERROR: invalid `repr(align)` attribute: not a power of two


error[E0589]: invalid `repr(align)` attribute: larger than 2^29
   |
   |
LL | #[repr(align(4294967296))] //~ ERROR: invalid `repr(align)` attribute: larger than 2^29


error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(0))] //~ ERROR: invalid `repr(align)` attribute: not a power of two


error[E0589]: invalid `repr(align)` attribute: not an unsuffixed integer
   |
   |
LL | #[repr(align(16.0))] //~ ERROR: invalid `repr(align)` attribute: not an unsuffixed integer


error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(15))] //~ ERROR: invalid `repr(align)` attribute: not a power of two


error[E0589]: invalid `repr(align)` attribute: larger than 2^29
   |
   |
LL | #[repr(align(4294967296))] //~ ERROR: invalid `repr(align)` attribute: larger than 2^29


error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(0))] //~ ERROR: invalid `repr(align)` attribute: not a power of two

##[error]error: internal compiler error: compiler/rustc_passes/src/check_attr.rs:1802:25: impossible case reached

thread 'rustc' panicked at compiler/rustc_passes/src/check_attr.rs:1802:25:
thread 'rustc' panicked at compiler/rustc_passes/src/check_attr.rs:1802:25:
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
   3: rustc_middle::ty::context::tls::with_opt::<rustc_middle::util::bug::opt_span_bug_fmt<rustc_span::span_encoding::Span>::{closure#0}, !>::{closure#0}
   4: 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}, !>
   5: rustc_middle::util::bug::bug_fmt
   6: <rustc_passes::check_attr::CheckAttrVisitor>::check_attributes
   6: <rustc_passes::check_attr::CheckAttrVisitor>::check_attributes
   7: <rustc_passes::check_attr::CheckAttrVisitor as rustc_hir::intravisit::Visitor>::visit_item
   8: <rustc_middle::hir::map::Map>::visit_item_likes_in_module::<rustc_passes::check_attr::CheckAttrVisitor>
   9: rustc_passes::check_attr::check_mod_attrs
      [... omitted 2 frames ...]
  10: <rustc_middle::hir::map::Map>::par_for_each_module::<rustc_interface::passes::run_required_analyses::{closure#0}::{closure#1}::{closure#0}::{closure#4}::{closure#0}>::{closure#0}
  11: <rustc_data_structures::sync::parallel::ParallelGuard>::run::<(), rustc_interface::passes::run_required_analyses::{closure#0}::{closure#0}::{closure#1}>
  12: <rustc_session::session::Session>::time::<(), rustc_interface::passes::run_required_analyses::{closure#0}>
  13: rustc_interface::passes::analysis
      [... omitted 2 frames ...]
  15: <rustc_interface::interface::Compiler>::enter::<rustc_driver_impl::run_compiler::{closure#0}::{closure#1}, core::result::Result<core::option::Option<rustc_interface::queries::Linker>, rustc_span::ErrorGuaranteed>>
  16: <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<core::result::Result<(), rustc_span::ErrorGuaranteed>, rustc_driver_impl::run_compiler::{closure#0}>::{closure#1}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>::{closure#0}::{closure#0}::{closure#0}, core::result::Result<(), rustc_span::ErrorGuaranteed>>
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 1.83.0-nightly (0faf11d8f 2024-10-12) running on x86_64-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
query stack during panic:
#0 [check_mod_attrs] checking attributes in top-level module
#1 [analysis] running analysis passes on this crate
end of query stack
---


---- [ui] tests/ui/repr/repr_align_greater_usize.rs#msp430 stdout ----

error in revision `msp430`: test compilation failed although it shouldn't!
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/repr/repr_align_greater_usize.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/x86_64-unknown-linux-gnu/stage2" "--cfg" "msp430" "--check-cfg" "cfg(FALSE,msp430,aarch32)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/repr/repr_align_greater_usize.msp430" "-A" "unused" "-A" "internal_features" "-Crpath" "-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/repr/repr_align_greater_usize.msp430/auxiliary" "--target=msp430-none-elf"
--- stderr -------------------------------
--- stderr -------------------------------
error[E0589]: alignment must not be greater than `isize::MAX` bytes
##[error]  --> /checkout/tests/ui/repr/repr_align_greater_usize.rs:22:8
   |
LL | #[repr(align(32768))]
   |
   = note: `isize::MAX` is 32767 for the current target


error[E0589]: alignment must not be greater than `isize::MAX` bytes
##[error]  --> /checkout/tests/ui/repr/repr_align_greater_usize.rs:25:8
   |
LL | #[repr(align(65536))]
   |
   = note: `isize::MAX` is 32767 for the current target

error: aborting due to 2 previous errors

[rust-log-analyzer]

The job x86_64-gnu-llvm-18 failed! Check out the build log: (web) (plain)

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

------
 > importing cache manifest from ghcr.io/rust-lang/rust-ci-cache:c32c805632780b5c1de330e3f44561b336c2efe163bc0990acb392390157a8e1d9f855d75914a239aa40c49d77f4a837247d05d2f8d46f554b98e1f46712a3e3:
------
##[endgroup]
Setting extra environment values for docker:  --env ENABLE_GCC_CODEGEN=1 --env GCC_EXEC_PREFIX=/usr/lib/gcc/
[CI_JOB_NAME=x86_64-gnu-llvm-18]
debug: `DISABLE_CI_RUSTC_IF_INCOMPATIBLE` configured.
---
sccache: Starting the server...
##[group]Configure the build
configure: processing command line
configure: 
configure: build.configure-args := ['--build=x86_64-unknown-linux-gnu', '--llvm-root=/usr/lib/llvm-18', '--enable-llvm-link-shared', '--set', 'rust.randomize-layout=true', '--set', 'rust.thin-lto-import-instr-limit=10', '--set', 'change-id=99999999', '--enable-verbose-configure', '--enable-sccache', '--disable-manage-submodules', '--enable-locked-deps', '--enable-cargo-native-static', '--set', 'rust.codegen-units-std=1', '--set', 'dist.compression-profile=balanced', '--dist-compression-formats=xz', '--set', 'rust.lld=false', '--disable-dist-src', '--release-channel=nightly', '--enable-debug-assertions', '--enable-overflow-checks', '--enable-llvm-assertions', '--set', 'rust.verify-llvm-ir', '--set', 'rust.codegen-backends=llvm,cranelift,gcc', '--set', 'llvm.static-libstdcpp', '--enable-new-symbol-mangling']
configure: target.x86_64-unknown-linux-gnu.llvm-config := /usr/lib/llvm-18/bin/llvm-config
configure: llvm.link-shared     := True
configure: rust.randomize-layout := True
configure: rust.thin-lto-import-instr-limit := 10
---
failures:

---- [ui] tests/ui/repr/repr_align_greater_usize.rs#msp430 stdout ----

error in revision `msp430`: test compilation failed although it shouldn't!
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/repr/repr_align_greater_usize.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/x86_64-unknown-linux-gnu/stage2" "--cfg" "msp430" "--check-cfg" "cfg(FALSE,msp430,aarch32)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/repr/repr_align_greater_usize.msp430" "-A" "unused" "-A" "internal_features" "-Crpath" "-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/repr/repr_align_greater_usize.msp430/auxiliary" "--target=msp430-none-elf"
--- stderr -------------------------------
--- stderr -------------------------------
error[E0589]: alignment must not be greater than `isize::MAX` bytes
##[error]  --> /checkout/tests/ui/repr/repr_align_greater_usize.rs:22:8
   |
LL | #[repr(align(32768))]
   |
   = note: `isize::MAX` is 32767 for the current target


error[E0589]: alignment must not be greater than `isize::MAX` bytes
##[error]  --> /checkout/tests/ui/repr/repr_align_greater_usize.rs:25:8
   |
LL | #[repr(align(65536))]
   |
   = note: `isize::MAX` is 32767 for the current target

error: aborting due to 2 previous errors

[asquared31415]

"test compilation failed even though it shouldn't"... but it's a build-fail test???

[jieyouxu]

"test compilation failed even though it shouldn't"... but it's a build-fail test???

https://github.com/rust-lang/rust/issues/130894

[rust-log-analyzer]

The job x86_64-gnu-llvm-18 failed! Check out the build log: (web) (plain)

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

------
 > importing cache manifest from ghcr.io/rust-lang/rust-ci-cache:c32c805632780b5c1de330e3f44561b336c2efe163bc0990acb392390157a8e1d9f855d75914a239aa40c49d77f4a837247d05d2f8d46f554b98e1f46712a3e3:
------
##[endgroup]
Setting extra environment values for docker:  --env ENABLE_GCC_CODEGEN=1 --env GCC_EXEC_PREFIX=/usr/lib/gcc/
[CI_JOB_NAME=x86_64-gnu-llvm-18]
debug: `DISABLE_CI_RUSTC_IF_INCOMPATIBLE` configured.
---
sccache: Starting the server...
##[group]Configure the build
configure: processing command line
configure: 
configure: build.configure-args := ['--build=x86_64-unknown-linux-gnu', '--llvm-root=/usr/lib/llvm-18', '--enable-llvm-link-shared', '--set', 'rust.randomize-layout=true', '--set', 'rust.thin-lto-import-instr-limit=10', '--set', 'change-id=99999999', '--enable-verbose-configure', '--enable-sccache', '--disable-manage-submodules', '--enable-locked-deps', '--enable-cargo-native-static', '--set', 'rust.codegen-units-std=1', '--set', 'dist.compression-profile=balanced', '--dist-compression-formats=xz', '--set', 'rust.lld=false', '--disable-dist-src', '--release-channel=nightly', '--enable-debug-assertions', '--enable-overflow-checks', '--enable-llvm-assertions', '--set', 'rust.verify-llvm-ir', '--set', 'rust.codegen-backends=llvm,cranelift,gcc', '--set', 'llvm.static-libstdcpp', '--enable-new-symbol-mangling']
configure: target.x86_64-unknown-linux-gnu.llvm-config := /usr/lib/llvm-18/bin/llvm-config
configure: llvm.link-shared     := True
configure: rust.randomize-layout := True
configure: rust.thin-lto-import-instr-limit := 10
---
  Downloaded boml v0.3.1
   Compiling boml v0.3.1
   Compiling y v0.1.0 (/checkout/compiler/rustc_codegen_gcc/build_system)
    Finished `release` profile [optimized] target(s) in 3.57s
     Running `/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-codegen/x86_64-unknown-linux-gnu/release/y test --use-system-gcc --use-backend gcc --out-dir /checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools/cg_gcc --release --mini-tests --std-tests`
Using system GCC
[BUILD] example
[AOT] mini_core_hello_world
/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools/cg_gcc/mini_core_hello_world
abc
---

---- [ui] tests/ui/repr/repr-align.rs stdout ----
diff of stderr:

46 LL | #[repr(align(0))]
48 
48 
+ error[E0589]: alignment must not be greater than `isize::MAX` bytes
+    |
+    |
+ LL | #[repr(align(4294967296))]
+    |
+    = note: `isize::MAX` is 2147483647 for the current target
+ 
+ 
+ error[E0589]: alignment must not be greater than `isize::MAX` bytes
+    |
+    |
+ LL | #[repr(align(4294967296))]
+    |
+    = note: `isize::MAX` is 2147483647 for the current target
+ 
+ 
49 error[E0589]: invalid `repr(align)` attribute: not an unsuffixed integer
51    |

110    |
110    |
111    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
- error: aborting due to 16 previous errors
+ error: aborting due to 18 previous errors
114 
115 For more information about this error, try `rustc --explain E0589`.
---
To only update this specific test, also pass `--test-args repr/repr-align.rs`

error: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/repr/repr-align.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/x86_64-unknown-linux-gnu/stage2" "--target=i686-unknown-linux-gnu" "--check-cfg" "cfg(FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/repr/repr-align" "-A" "unused" "-A" "internal_features" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/i686-unknown-linux-gnu/native/rust-test-helpers" "-Clinker=x86_64-linux-gnu-gcc" "-L" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/repr/repr-align/auxiliary"
--- stderr -------------------------------
--- stderr -------------------------------
error[E0589]: invalid `repr(align)` attribute: not an unsuffixed integer
   |
   |
LL | #[repr(align(16.0))] //~ ERROR: invalid `repr(align)` attribute: not an unsuffixed integer


error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(15))] //~ ERROR: invalid `repr(align)` attribute: not a power of two


error[E0589]: invalid `repr(align)` attribute: larger than 2^29
   |
   |
LL | #[repr(align(4294967296))] //~ ERROR: invalid `repr(align)` attribute: larger than 2^29


error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(0))] //~ ERROR: invalid `repr(align)` attribute: not a power of two


error[E0589]: invalid `repr(align)` attribute: not an unsuffixed integer
   |
   |
LL | #[repr(align(16.0))] //~ ERROR: invalid `repr(align)` attribute: not an unsuffixed integer


error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(15))] //~ ERROR: invalid `repr(align)` attribute: not a power of two


error[E0589]: invalid `repr(align)` attribute: larger than 2^29
   |
   |
LL | #[repr(align(4294967296))] //~ ERROR: invalid `repr(align)` attribute: larger than 2^29


error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(0))] //~ ERROR: invalid `repr(align)` attribute: not a power of two


error[E0589]: alignment must not be greater than `isize::MAX` bytes
   |
   |
LL | #[repr(align(4294967296))] //~ ERROR: invalid `repr(align)` attribute: larger than 2^29
   |
   = note: `isize::MAX` is 2147483647 for the current target


error[E0589]: alignment must not be greater than `isize::MAX` bytes
   |
   |
LL | #[repr(align(4294967296))] //~ ERROR: invalid `repr(align)` attribute: larger than 2^29
   |
   = note: `isize::MAX` is 2147483647 for the current target


error[E0589]: invalid `repr(align)` attribute: not an unsuffixed integer
   |
   |
LL | #[repr(align(16.0))] //~ ERROR: invalid `repr(align)` attribute: not an unsuffixed integer
   |
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(15))] //~ ERROR: invalid `repr(align)` attribute: not a power of two
   |
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0589]: invalid `repr(align)` attribute: larger than 2^29
   |
   |
LL | #[repr(align(4294967296))] //~ ERROR: invalid `repr(align)` attribute: larger than 2^29
   |
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(0))] //~ ERROR: invalid `repr(align)` attribute: not a power of two
   |
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0589]: invalid `repr(align)` attribute: not an unsuffixed integer
   |
   |
LL | #[repr(align(16.0))] //~ ERROR: invalid `repr(align)` attribute: not an unsuffixed integer
   |
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(15))] //~ ERROR: invalid `repr(align)` attribute: not a power of two
   |
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0589]: invalid `repr(align)` attribute: larger than 2^29
   |
   |
LL | #[repr(align(4294967296))] //~ ERROR: invalid `repr(align)` attribute: larger than 2^29
   |
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0589]: invalid `repr(align)` attribute: not a power of two
   |
   |
LL | #[repr(align(0))] //~ ERROR: invalid `repr(align)` attribute: not a power of two
   |
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
error: aborting due to 18 previous errors

For more information about this error, try `rustc --explain E0589`.
------------------------------------------

[nnethercote]

r? @workingjubilee

[zachs18]

as repr(align) also increases the size of the type, and that would be larger than the maximum allowed size of objects.

repr(align) can be applied to unit/ZST structs without increasing their size, so #[repr(align(32768))] struct ZST; is possible on 16-bit targets and currently does not error. (though it might be enough of an edge case to disallow anyway).

#![no_std]

#[repr(align(32768))]
struct Hello;

pub fn foo() -> usize { core::mem::align_of::<Hello>() }

This currently compiles fine with cargo +nightly build -Z build-std=core --target avr-unknown-gnu-atmega328 --release, but fails on this branch with

error[E0589]: alignment must not be greater than `isize::MAX` bytes
 --> src/lib.rs:4:8
  |
4 | #[repr(align(32768))]
  |        ^^^^^^^^^^^^
  |
  = note: `isize::MAX` is 32767 for the current target

For more information about this error, try `rustc --explain E0589`.

[workingjubilee]

cc @Patryk27 as prospective maintainer for AVR cc @cr1901 because you're the one who comes to mind re: MSP430

You are the only targets affected by this, as all other targets have a bound on repr(align(N)) that is already below isize::MAX, functionally imposed by our codegen backends.

Do you think this #[repr(align(32768))] struct Hello16BitAlign; has any real use-case on AVR? Even a somewhat silly one?

Note that #[repr(align(16384))] struct Hello16BitSize(u8); is the limit for actually-sized types.

[asquared31415]

ah i see, i was under the impression repr(align) increased the size for structs that would otherwise be 1-ZSTs, i can probably add an exception if it's needed then? i do think this is a slightly weird use case, but i'm mostly neutral on this, and dont work with any 16 bit targets for rust to know what they might need.

[cr1901]

I've never used Rust on an MSP430 with more than 10kB (8+2kB) of RAM. MSP430's max out at 512kB ROM and 66kB RAM.

However, from what I can gather, actual existing MSP430s top out at 18kB (16+2kB) of RAM without relying on stuff unsupported by LLVM. Given such constraints, #[repr(align(32768))]- or even #[repr(align(16384))], or #[repr(align(8192))], etc- isn't usable in practice.

If LLVM gets these features to access 20-bit addresses, I don't see how I'd use such functionality for RAM; you only have 64kB continguous RAM anyway- the other 2kB is a ~~marketing gimmick~~ "bonus" if you're not using the USB peripheral, at a much lower address than the rest of RAM. And having 20 ZSTs 32kB apart in ROM doesn't seem that useful either.

[Patryk27]

Do you think this #[repr(align(32768))] struct Hello16BitAlign; has any real use-case on AVR? Even a somewhat silly one?

I don't think so - I mean, I think ideally we'd throw this error on instantiating the struct, so that a mere fact of such type existing wasn't a failure (as in @zachs18's example), but I think there's no point in doing more complex analysis considering it's already quite an edge case.

[workingjubilee]

Okay!

Then if people using the targets cannot think of a good reason for us to support an alignment greater than isize::MAX, zero-sized type or no: let us not, and keep the rule consistent.

[workingjubilee]

Unfortunately I don't know that this is the right place to emit this check, so having determined that, its implementation seems correct, but it would be good if someone with experience with rustc_passes could actually weigh in.

[workingjubilee]

hmm, recent history (and a coinflip) says...

r? @jieyouxu

[asquared31415]

Unfortunately I don't know that this is the right place to emit this check [...]

I explored an alternative approach doing the error in the same location that the 2^64 check was emitted in rustc_attr::builtin::parse_alignment, but was unsatisfied with how the &'static str error type was being used and changing the call sites seemed non-trivial because it is used for repr(packed) as well.

... on further thought, should this isize::MAX check be done for repr(packed(N))? Since repr(packed) can only lower alignment, it's probably not necessary?

[jieyouxu]

@rustbot author

[asquared31415]

@rustbot ready

will open a zulip thread about the potential follow up PR for repr(align), though personally i don't think it's necessary

[jieyouxu]

Dropped the redundant check-fail, no other changes. @bors r+ rollup=iffy

[bors]

:pushpin: Commit 6fc7ce43d2f2cd2fef1b75c9c59f13f312e0d9d8 has been approved by jieyouxu

It is now in the queue for this repository.

[bors]

:hourglass: Testing commit 6fc7ce43d2f2cd2fef1b75c9c59f13f312e0d9d8 with merge 66701c42263042f7120385725606edeb987ad4f1...