rust/tests/codegen/error-provide.rs

51 lines
1.3 KiB
Rust

// Codegen test for #126242
//@ compile-flags: -O
#![crate_type = "lib"]
#![feature(error_generic_member_access)]
use std::error::Request;
use std::fmt;
#[derive(Debug)]
struct MyBacktrace1 {}
#[derive(Debug)]
struct MyBacktrace2 {}
#[derive(Debug)]
struct MyBacktrace3 {}
#[derive(Debug)]
struct MyError {
backtrace1: MyBacktrace1,
backtrace2: MyBacktrace2,
backtrace3: MyBacktrace3,
other: MyBacktrace3,
}
impl fmt::Display for MyError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "Example Error")
}
}
impl std::error::Error for MyError {
// CHECK-LABEL: @provide
#[no_mangle]
fn provide<'a>(&'a self, request: &mut Request<'a>) {
// LLVM should be able to optimize multiple .provide_* calls into a switch table
// and eliminate redundant ones, rather than compare one-by-one.
// CHECK-NEXT: start:
// CHECK-NEXT: %[[SCRUTINEE:[^ ]+]] = load i64, ptr
// CHECK-NEXT: switch i64 %[[SCRUTINEE]], label %{{.*}} [
// CHECK-COUNT-3: i64 {{.*}}, label %{{.*}}
// CHECK-NEXT: ]
request
.provide_ref::<MyBacktrace1>(&self.backtrace1)
.provide_ref::<MyBacktrace3>(&self.other)
.provide_ref::<MyBacktrace2>(&self.backtrace2)
.provide_ref::<MyBacktrace3>(&self.backtrace3);
}
}