rust-analyzer - Unnamed repository; edit this file 'description' to name the repository.


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148

use base_db::fixture::WithFixture;
use hir_def::{db::DefDatabase, expr::Literal};

use crate::{consteval::ComputedExpr, db::HirDatabase, test_db::TestDB};

use super::ConstEvalError;

fn check_fail(ra_fixture: &str, error: ConstEvalError) {
    assert_eq!(eval_goal(ra_fixture), Err(error));
}

fn check_number(ra_fixture: &str, answer: i128) {
    let r = eval_goal(ra_fixture).unwrap();
    match r {
        ComputedExpr::Literal(Literal::Int(r, _)) => assert_eq!(r, answer),
        ComputedExpr::Literal(Literal::Uint(r, _)) => assert_eq!(r, answer as u128),
        x => panic!("Expected number but found {:?}", x),
    }
}

fn eval_goal(ra_fixture: &str) -> Result<ComputedExpr, ConstEvalError> {
    let (db, file_id) = TestDB::with_single_file(ra_fixture);
    let module_id = db.module_for_file(file_id);
    let def_map = module_id.def_map(&db);
    let scope = &def_map[module_id.local_id].scope;
    let const_id = scope
        .declarations()
        .into_iter()
        .find_map(|x| match x {
            hir_def::ModuleDefId::ConstId(x) => {
                if db.const_data(x).name.as_ref()?.to_string() == "GOAL" {
                    Some(x)
                } else {
                    None
                }
            }
            _ => None,
        })
        .unwrap();
    db.const_eval(const_id)
}

#[test]
fn add() {
    check_number(r#"const GOAL: usize = 2 + 2;"#, 4);
}

#[test]
fn bit_op() {
    check_number(r#"const GOAL: u8 = !0 & !(!0 >> 1)"#, 128);
    check_number(r#"const GOAL: i8 = !0 & !(!0 >> 1)"#, 0);
    // FIXME: rustc evaluate this to -128
    check_fail(
        r#"const GOAL: i8 = 1 << 7"#,
        ConstEvalError::Panic("attempt to run invalid arithmetic operation".to_string()),
    );
    check_fail(
        r#"const GOAL: i8 = 1 << 8"#,
        ConstEvalError::Panic("attempt to run invalid arithmetic operation".to_string()),
    );
}

#[test]
fn locals() {
    check_number(
        r#"
    const GOAL: usize = {
        let a = 3 + 2;
        let b = a * a;
        b
    };
    "#,
        25,
    );
}

#[test]
fn consts() {
    check_number(
        r#"
    const F1: i32 = 1;
    const F3: i32 = 3 * F2;
    const F2: i32 = 2 * F1;
    const GOAL: i32 = F3;
    "#,
        6,
    );
}

#[test]
fn const_loop() {
    check_fail(
        r#"
    const F1: i32 = 1 * F3;
    const F3: i32 = 3 * F2;
    const F2: i32 = 2 * F1;
    const GOAL: i32 = F3;
    "#,
        ConstEvalError::Loop,
    );
}

#[test]
fn const_impl_assoc() {
    check_number(
        r#"
    struct U5;
    impl U5 {
        const VAL: usize = 5;
    }
    const GOAL: usize = U5::VAL;
    "#,
        5,
    );
}

#[test]
fn const_generic_subst() {
    // FIXME: this should evaluate to 5
    check_fail(
        r#"
    struct Adder<const N: usize, const M: usize>;
    impl<const N: usize, const M: usize> Adder<N, M> {
        const VAL: usize = N + M;
    }
    const GOAL: usize = Adder::<2, 3>::VAL;
    "#,
        ConstEvalError::NotSupported("const generic without substitution"),
    );
}

#[test]
fn const_trait_assoc() {
    // FIXME: this should evaluate to 0
    check_fail(
        r#"
    struct U0;
    trait ToConst {
        const VAL: usize;
    }
    impl ToConst for U0 {
        const VAL: usize = 0;
    }
    const GOAL: usize = U0::VAL;
    "#,
        ConstEvalError::IncompleteExpr,
    );
}