rust/tests/ui/consts/const-eval/unwind-abort.rs

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rustc: Fill out remaining parts of C-unwind ABI This commit intends to fill out some of the remaining pieces of the C-unwind ABI. This has a number of other changes with it though to move this design space forward a bit. Notably contained within here is: * On `panic=unwind`, the `extern "C"` ABI is now considered as "may unwind". This fixes a longstanding soundness issue where if you `panic!()` in an `extern "C"` function defined in Rust that's actually UB because the LLVM representation for the function has the `nounwind` attribute, but then you unwind. * Whether or not a function unwinds now mainly considers the ABI of the function instead of first checking the panic strategy. This fixes a miscompile of `extern "C-unwind"` with `panic=abort` because that ABI can still unwind. * The aborting stub for non-unwinding ABIs with `panic=unwind` has been reimplemented. Previously this was done as a small tweak during MIR generation, but this has been moved to a separate and dedicated MIR pass. This new pass will, for appropriate functions and function calls, insert a `cleanup` landing pad for any function call that may unwind within a function that is itself not allowed to unwind. Note that this subtly changes some behavior from before where previously on an unwind which was caught-to-abort it would run active destructors in the function, and now it simply immediately aborts the process. * The `#[unwind]` attribute has been removed and all users in tests and such are now using `C-unwind` and `#![feature(c_unwind)]`. I think this is largely the last piece of the RFC to implement. Unfortunately I believe this is still not stabilizable as-is because activating the feature gate changes the behavior of the existing `extern "C"` ABI in a way that has no replacement. My thinking for how to enable this is that we add support for the `C-unwind` ABI on stable Rust first, and then after it hits stable we change the behavior of the `C` ABI. That way anyone straddling stable/beta/nightly can switch to `C-unwind` safely.
2021-06-08 18:23:58 +00:00
const extern "C" fn foo() {
Shorten span of panic failures in const context Previously, we included a redundant prefix on the panic message and a postfix of the location of the panic. The prefix didn't carry any additional information beyond "something failed", and the location of the panic is redundant with the diagnostic's span, which gets printed out even if its code is not shown. ``` error[E0080]: evaluation of constant value failed --> $DIR/assert-type-intrinsics.rs:11:9 | LL | MaybeUninit::<!>::uninit().assume_init(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation panicked: aborted execution: attempted to instantiate uninhabited type `!` ``` ``` error[E0080]: evaluation of `Fail::<i32>::C` failed --> $DIR/collect-in-dead-closure.rs:9:19 | LL | const C: () = panic!(); | ^^^^^^^^ evaluation panicked: explicit panic | = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` ``` error[E0080]: evaluation of constant value failed --> $DIR/uninhabited.rs:41:9 | LL | assert!(false); | ^^^^^^^^^^^^^^ evaluation panicked: assertion failed: false | = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info) ``` --- When the primary span for a const error is the same as the first frame in the const error report, skip it. ``` error[E0080]: evaluation of constant value failed --> $DIR/issue-88434-removal-index-should-be-less.rs:3:24 | LL | const _CONST: &[u8] = &f(&[], |_| {}); | ^^^^^^^^^^^^^^ evaluation panicked: explicit panic | note: inside `f::<{closure@$DIR/issue-88434-removal-index-should-be-less.rs:3:31: 3:34}>` --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ the failure occurred here = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` instead of ``` error[E0080]: evaluation of constant value failed --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ explicit panic | note: inside `f::<{closure@$DIR/issue-88434-removal-index-should-be-less.rs:3:31: 3:34}>` --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ note: inside `_CONST` --> $DIR/issue-88434-removal-index-should-be-less.rs:3:24 | LL | const _CONST: &[u8] = &f(&[], |_| {}); | ^^^^^^^^^^^^^^ = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` --- Revert order of constant evaluation errors Point at the code the user wrote first and std functions last. ``` error[E0080]: evaluation of constant value failed --> $DIR/const-errs-dont-conflict-103369.rs:5:25 | LL | impl ConstGenericTrait<{my_fn(1)}> for () {} | ^^^^^^^^ evaluation panicked: Some error occurred | note: called from `my_fn` --> $DIR/const-errs-dont-conflict-103369.rs:10:5 | LL | panic!("Some error occurred"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` instead of ``` error[E0080]: evaluation of constant value failed --> $DIR/const-errs-dont-conflict-103369.rs:10:5 | LL | panic!("Some error occurred"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Some error occurred | note: called from `<() as ConstGenericTrait<{my_fn(1)}>>::{constant#0}` --> $DIR/const-errs-dont-conflict-103369.rs:5:25 | LL | impl ConstGenericTrait<{my_fn(1)}> for () {} | ^^^^^^^^ = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ```
2025-02-03 18:43:55 +00:00
panic!() //~ inside `foo`
}
Shorten span of panic failures in const context Previously, we included a redundant prefix on the panic message and a postfix of the location of the panic. The prefix didn't carry any additional information beyond "something failed", and the location of the panic is redundant with the diagnostic's span, which gets printed out even if its code is not shown. ``` error[E0080]: evaluation of constant value failed --> $DIR/assert-type-intrinsics.rs:11:9 | LL | MaybeUninit::<!>::uninit().assume_init(); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation panicked: aborted execution: attempted to instantiate uninhabited type `!` ``` ``` error[E0080]: evaluation of `Fail::<i32>::C` failed --> $DIR/collect-in-dead-closure.rs:9:19 | LL | const C: () = panic!(); | ^^^^^^^^ evaluation panicked: explicit panic | = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` ``` error[E0080]: evaluation of constant value failed --> $DIR/uninhabited.rs:41:9 | LL | assert!(false); | ^^^^^^^^^^^^^^ evaluation panicked: assertion failed: false | = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info) ``` --- When the primary span for a const error is the same as the first frame in the const error report, skip it. ``` error[E0080]: evaluation of constant value failed --> $DIR/issue-88434-removal-index-should-be-less.rs:3:24 | LL | const _CONST: &[u8] = &f(&[], |_| {}); | ^^^^^^^^^^^^^^ evaluation panicked: explicit panic | note: inside `f::<{closure@$DIR/issue-88434-removal-index-should-be-less.rs:3:31: 3:34}>` --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ the failure occurred here = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` instead of ``` error[E0080]: evaluation of constant value failed --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ explicit panic | note: inside `f::<{closure@$DIR/issue-88434-removal-index-should-be-less.rs:3:31: 3:34}>` --> $DIR/issue-88434-removal-index-should-be-less.rs:10:5 | LL | panic!() | ^^^^^^^^ note: inside `_CONST` --> $DIR/issue-88434-removal-index-should-be-less.rs:3:24 | LL | const _CONST: &[u8] = &f(&[], |_| {}); | ^^^^^^^^^^^^^^ = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` --- Revert order of constant evaluation errors Point at the code the user wrote first and std functions last. ``` error[E0080]: evaluation of constant value failed --> $DIR/const-errs-dont-conflict-103369.rs:5:25 | LL | impl ConstGenericTrait<{my_fn(1)}> for () {} | ^^^^^^^^ evaluation panicked: Some error occurred | note: called from `my_fn` --> $DIR/const-errs-dont-conflict-103369.rs:10:5 | LL | panic!("Some error occurred"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ``` instead of ``` error[E0080]: evaluation of constant value failed --> $DIR/const-errs-dont-conflict-103369.rs:10:5 | LL | panic!("Some error occurred"); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Some error occurred | note: called from `<() as ConstGenericTrait<{my_fn(1)}>>::{constant#0}` --> $DIR/const-errs-dont-conflict-103369.rs:5:25 | LL | impl ConstGenericTrait<{my_fn(1)}> for () {} | ^^^^^^^^ = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info) ```
2025-02-03 18:43:55 +00:00
const _: () = foo(); //~ ERROR evaluation of constant value failed
rustc: Fill out remaining parts of C-unwind ABI This commit intends to fill out some of the remaining pieces of the C-unwind ABI. This has a number of other changes with it though to move this design space forward a bit. Notably contained within here is: * On `panic=unwind`, the `extern "C"` ABI is now considered as "may unwind". This fixes a longstanding soundness issue where if you `panic!()` in an `extern "C"` function defined in Rust that's actually UB because the LLVM representation for the function has the `nounwind` attribute, but then you unwind. * Whether or not a function unwinds now mainly considers the ABI of the function instead of first checking the panic strategy. This fixes a miscompile of `extern "C-unwind"` with `panic=abort` because that ABI can still unwind. * The aborting stub for non-unwinding ABIs with `panic=unwind` has been reimplemented. Previously this was done as a small tweak during MIR generation, but this has been moved to a separate and dedicated MIR pass. This new pass will, for appropriate functions and function calls, insert a `cleanup` landing pad for any function call that may unwind within a function that is itself not allowed to unwind. Note that this subtly changes some behavior from before where previously on an unwind which was caught-to-abort it would run active destructors in the function, and now it simply immediately aborts the process. * The `#[unwind]` attribute has been removed and all users in tests and such are now using `C-unwind` and `#![feature(c_unwind)]`. I think this is largely the last piece of the RFC to implement. Unfortunately I believe this is still not stabilizable as-is because activating the feature gate changes the behavior of the existing `extern "C"` ABI in a way that has no replacement. My thinking for how to enable this is that we add support for the `C-unwind` ABI on stable Rust first, and then after it hits stable we change the behavior of the `C` ABI. That way anyone straddling stable/beta/nightly can switch to `C-unwind` safely.
2021-06-08 18:23:58 +00:00
// Ensure that the CTFE engine handles calls to `extern "C"` aborting gracefully
fn main() {
foo();
}