rust/src/test/codegen-units/item-collection/trait-method-default-impl.rs

// compile-flags:-Zprint-mono-items=eager

#![deny(dead_code)]
#![feature(start)]

trait SomeTrait {
    fn foo(&self) { }
    fn bar<T>(&self, x: T) -> T { x }
}

impl SomeTrait for i8 {
    // take the default implementations

    // For the non-generic foo(), we should generate a codegen-item even if it
    // is not called anywhere
    //~ MONO_ITEM fn trait_method_default_impl::SomeTrait[0]::foo[0]<i8>
}

trait SomeGenericTrait<T1> {
    fn foo(&self) { }
    fn bar<T2>(&self, x: T1, y: T2) {}
}

// Non-generic impl of generic trait
impl SomeGenericTrait<u64> for i32 {
    // take the default implementations

    // For the non-generic foo(), we should generate a codegen-item even if it
    // is not called anywhere
    //~ MONO_ITEM fn trait_method_default_impl::SomeGenericTrait[0]::foo[0]<i32, T1>
}

// Non-generic impl of generic trait
impl<T1> SomeGenericTrait<T1> for u32 {
    // take the default implementations
    // since nothing is monomorphic here, nothing should be generated unless used somewhere.
}

//~ MONO_ITEM fn trait_method_default_impl::start[0]
#[start]
fn start(_: isize, _: *const *const u8) -> isize {
    //~ MONO_ITEM fn trait_method_default_impl::SomeTrait[0]::bar[0]<i8, char>
    let _ = 1i8.bar('c');

    //~ MONO_ITEM fn trait_method_default_impl::SomeTrait[0]::bar[0]<i8, &str>
    let _ = 2i8.bar("&str");

    //~ MONO_ITEM fn trait_method_default_impl::SomeGenericTrait[0]::bar[0]<i32, u64, char>
    0i32.bar(0u64, 'c');

    //~ MONO_ITEM fn trait_method_default_impl::SomeGenericTrait[0]::bar[0]<i32, u64, &str>
    0i32.bar(0u64, "&str");

    //~ MONO_ITEM fn trait_method_default_impl::SomeGenericTrait[0]::bar[0]<u32, i8, &[char; 1]>
    0u32.bar(0i8, &['c']);

    //~ MONO_ITEM fn trait_method_default_impl::SomeGenericTrait[0]::bar[0]<u32, i16, ()>
    0u32.bar(0i16, ());

    0
}