rust/src/test/codegen-units/partitioning/vtable-through-const.rs

// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

// ignore-tidy-linelength

// We specify -Z incremental here because we want to test the partitioning for
// incremental compilation
// compile-flags:-Zprint-trans-items=lazy -Zincremental=tmp/partitioning-tests/vtable-through-const

// This test case makes sure, that references made through constants are
// recorded properly in the InliningMap.

mod mod1 {
    pub trait Trait1 {
        fn do_something(&self) {}
        fn do_something_else(&self) {}
    }

    impl Trait1 for u32 {}

    pub trait Trait1Gen<T> {
        fn do_something(&self, x: T) -> T;
        fn do_something_else(&self, x: T) -> T;
    }

    impl<T> Trait1Gen<T> for u32 {
        fn do_something(&self, x: T) -> T { x }
        fn do_something_else(&self, x: T) -> T { x }
    }

    fn id<T>(x: T) -> T { x }

    // These are referenced, so they produce trans-items (see main())
    pub const TRAIT1_REF: &'static Trait1 = &0u32 as &Trait1;
    pub const TRAIT1_GEN_REF: &'static Trait1Gen<u8> = &0u32 as &Trait1Gen<u8>;
    pub const ID_CHAR: fn(char) -> char = id::<char>;



    pub trait Trait2 {
        fn do_something(&self) {}
        fn do_something_else(&self) {}
    }

    impl Trait2 for u32 {}

    pub trait Trait2Gen<T> {
        fn do_something(&self, x: T) -> T;
        fn do_something_else(&self, x: T) -> T;
    }

    impl<T> Trait2Gen<T> for u32 {
        fn do_something(&self, x: T) -> T { x }
        fn do_something_else(&self, x: T) -> T { x }
    }

    // These are not referenced, so they do not produce trans-items
    pub const TRAIT2_REF: &'static Trait2 = &0u32 as &Trait2;
    pub const TRAIT2_GEN_REF: &'static Trait2Gen<u8> = &0u32 as &Trait2Gen<u8>;
    pub const ID_I64: fn(i64) -> i64 = id::<i64>;
}

//~ TRANS_ITEM fn vtable_through_const::main[0] @@ vtable_through_const[External]
fn main() {
    //~ TRANS_ITEM fn core::ptr[0]::drop_in_place[0]<u32> @@ vtable_through_const[Internal]

    // Since Trait1::do_something() is instantiated via its default implementation,
    // it is considered a generic and is instantiated here only because it is
    // referenced in this module.
    //~ TRANS_ITEM fn vtable_through_const::mod1[0]::Trait1[0]::do_something_else[0]<u32> @@ vtable_through_const-mod1.volatile[External]

    // Although it is never used, Trait1::do_something_else() has to be
    // instantiated locally here too, otherwise the <&u32 as &Trait1> vtable
    // could not be fully constructed.
    //~ TRANS_ITEM fn vtable_through_const::mod1[0]::Trait1[0]::do_something[0]<u32> @@ vtable_through_const-mod1.volatile[External]
    mod1::TRAIT1_REF.do_something();

    // Same as above
    //~ TRANS_ITEM fn vtable_through_const::mod1[0]::{{impl}}[1]::do_something[0]<u8> @@ vtable_through_const-mod1.volatile[External]
    //~ TRANS_ITEM fn vtable_through_const::mod1[0]::{{impl}}[1]::do_something_else[0]<u8> @@ vtable_through_const-mod1.volatile[External]
    mod1::TRAIT1_GEN_REF.do_something(0u8);

    //~ TRANS_ITEM fn vtable_through_const::mod1[0]::id[0]<char> @@ vtable_through_const-mod1.volatile[External]
    mod1::ID_CHAR('x');
}