rust/tests/run-make/c-unwind-abi-catch-panic/main.rs

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add integration tests, unwind across FFI boundary ### Integration Tests This commit introduces some new fixtures to the `run-make-fulldeps` test suite. * c-unwind-abi-catch-panic: Exercise unwinding a panic. This catches a panic across an FFI boundary and downcasts it into an integer. * c-unwind-abi-catch-lib-panic: This is similar to the previous `*catch-panic` test, however in this case the Rust code that panics resides in a separate crate. ### Add `rust_eh_personality` to `#[no_std]` alloc tests This commit addresses some test failures that now occur in the following two tests: * no_std-alloc-error-handler-custom.rs * no_std-alloc-error-handler-default.rs Each test now defines a `rust_eh_personality` extern function, in the same manner as shown in the "Writing an executable without stdlib" section of the `lang_items` documentation here: https://doc.rust-lang.org/unstable-book/language-features/lang-items.html#writing-an-executable-without-stdlib Without this change, these tests would fail to compile due to a linking error explaining that there was an "undefined reference to `rust_eh_personality'." ### Updated hash * update 32-bit hash in `impl1` test ### Panics This commit uses `panic!` macro invocations that return a string, rather than using an integer as a panic payload. Doing so avoids the following warnings that were observed during rollup for the `*-msvc-1` targets: ``` warning: panic message is not a string literal --> panic.rs:10:16 | 10 | panic!(x); // That is too big! | ^ | = note: `#[warn(non_fmt_panic)]` on by default = note: this is no longer accepted in Rust 2021 help: add a "{}" format string to Display the message | 10 | panic!("{}", x); // That is too big! | ^^^^^ help: or use std::panic::panic_any instead | 10 | std::panic::panic_any(x); // That is too big! | ^^^^^^^^^^^^^^^^^^^^^ warning: 1 warning emitted ``` See: https://github.com/rust-lang-ci/rust/runs/1992118428 As these errors imply, panicking without a format string will be disallowed in Rust 2021, per #78500.
2020-12-11 19:54:47 -06:00
//! A test for calling `C-unwind` functions across foreign function boundaries.
//!
//! This test triggers a panic when calling a foreign function that calls *back* into Rust.
#![feature(c_unwind)]
use std::panic::{catch_unwind, AssertUnwindSafe};
fn main() {
// Call `add_small_numbers`, passing arguments that will NOT trigger a panic.
let (a, b) = (9, 1);
let c = unsafe { add_small_numbers(a, b) };
assert_eq!(c, 10);
// Call `add_small_numbers`, passing arguments that will trigger a panic, and catch it.
let caught_unwind = catch_unwind(AssertUnwindSafe(|| {
let (a, b) = (10, 1);
let _c = unsafe { add_small_numbers(a, b) };
unreachable!("should have unwound instead of returned");
}));
// Assert that we did indeed panic, then unwrap and downcast the panic into the sum.
assert!(caught_unwind.is_err());
let panic_obj = caught_unwind.unwrap_err();
let msg = panic_obj.downcast_ref::<String>().unwrap();
assert_eq!(msg, "11");
}
#[link(name = "add", kind = "static")]
extern "C-unwind" {
/// An external function, defined in C.
///
/// Returns the sum of two numbers, or panics if the sum is greater than 10.
fn add_small_numbers(a: u32, b: u32) -> u32;
}
/// This function will panic if `x` is greater than 10.
///
/// This function is called by `add_small_numbers`.
#[no_mangle]
pub extern "C-unwind" fn panic_if_greater_than_10(x: u32) {
if x > 10 {
panic!("{}", x); // That is too big!
}
}