aboutsummaryrefslogtreecommitdiff
path: root/crates/ra_hir/src/expr.rs
blob: 8bfdda45e12604f101a96a6d81c00bec63911ac4 (plain)
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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
//! FIXME: write short doc here

use std::sync::Arc;

use hir_def::path::known;
use hir_expand::diagnostics::DiagnosticSink;
use ra_syntax::ast;
use ra_syntax::AstPtr;
use rustc_hash::FxHashSet;

use crate::{
    db::HirDatabase,
    diagnostics::{MissingFields, MissingOkInTailExpr},
    ty::{ApplicationTy, InferenceResult, Ty, TypeCtor},
    Adt, DefWithBody, Function, HasBody, Name, Path, Resolver,
};

pub use hir_def::{
    body::{
        scope::{ExprScopes, ScopeEntry, ScopeId},
        Body, BodySourceMap, ExprPtr, ExprSource, PatPtr, PatSource,
    },
    expr::{
        ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Literal, LogicOp,
        MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField, Statement, UnaryOp,
    },
};

// needs arbitrary_self_types to be a method... or maybe move to the def?
pub(crate) fn resolver_for_expr(
    db: &impl HirDatabase,
    owner: DefWithBody,
    expr_id: ExprId,
) -> Resolver {
    let scopes = owner.expr_scopes(db);
    resolver_for_scope(db, owner, scopes.scope_for(expr_id))
}

pub(crate) fn resolver_for_scope(
    db: &impl HirDatabase,
    owner: DefWithBody,
    scope_id: Option<ScopeId>,
) -> Resolver {
    let mut r = owner.resolver(db);
    let scopes = owner.expr_scopes(db);
    let scope_chain = scopes.scope_chain(scope_id).collect::<Vec<_>>();
    for scope in scope_chain.into_iter().rev() {
        r = r.push_expr_scope(owner, Arc::clone(&scopes), scope);
    }
    r
}

pub(crate) struct ExprValidator<'a, 'b: 'a> {
    func: Function,
    infer: Arc<InferenceResult>,
    sink: &'a mut DiagnosticSink<'b>,
}

impl<'a, 'b> ExprValidator<'a, 'b> {
    pub(crate) fn new(
        func: Function,
        infer: Arc<InferenceResult>,
        sink: &'a mut DiagnosticSink<'b>,
    ) -> ExprValidator<'a, 'b> {
        ExprValidator { func, infer, sink }
    }

    pub(crate) fn validate_body(&mut self, db: &impl HirDatabase) {
        let body = self.func.body(db);

        for e in body.exprs() {
            if let (id, Expr::RecordLit { path, fields, spread }) = e {
                self.validate_record_literal(id, path, fields, *spread, db);
            }
        }

        let body_expr = &body[body.body_expr()];
        if let Expr::Block { statements: _, tail: Some(t) } = body_expr {
            self.validate_results_in_tail_expr(body.body_expr(), *t, db);
        }
    }

    fn validate_record_literal(
        &mut self,
        id: ExprId,
        _path: &Option<Path>,
        fields: &[RecordLitField],
        spread: Option<ExprId>,
        db: &impl HirDatabase,
    ) {
        if spread.is_some() {
            return;
        }

        let struct_def = match self.infer[id].as_adt() {
            Some((Adt::Struct(s), _)) => s,
            _ => return,
        };

        let lit_fields: FxHashSet<_> = fields.iter().map(|f| &f.name).collect();
        let missed_fields: Vec<Name> = struct_def
            .fields(db)
            .iter()
            .filter_map(|f| {
                let name = f.name(db);
                if lit_fields.contains(&name) {
                    None
                } else {
                    Some(name)
                }
            })
            .collect();
        if missed_fields.is_empty() {
            return;
        }
        let source_map = self.func.body_source_map(db);

        if let Some(source_ptr) = source_map.expr_syntax(id) {
            if let Some(expr) = source_ptr.value.a() {
                let root = source_ptr.file_syntax(db);
                if let ast::Expr::RecordLit(record_lit) = expr.to_node(&root) {
                    if let Some(field_list) = record_lit.record_field_list() {
                        self.sink.push(MissingFields {
                            file: source_ptr.file_id,
                            field_list: AstPtr::new(&field_list),
                            missed_fields,
                        })
                    }
                }
            }
        }
    }

    fn validate_results_in_tail_expr(
        &mut self,
        body_id: ExprId,
        id: ExprId,
        db: &impl HirDatabase,
    ) {
        // the mismatch will be on the whole block currently
        let mismatch = match self.infer.type_mismatch_for_expr(body_id) {
            Some(m) => m,
            None => return,
        };

        let std_result_path = known::std_result_result();

        let resolver = self.func.resolver(db);
        let std_result_enum = match resolver.resolve_known_enum(db, &std_result_path) {
            Some(it) => it,
            _ => return,
        };

        let std_result_ctor = TypeCtor::Adt(Adt::Enum(std_result_enum));
        let params = match &mismatch.expected {
            Ty::Apply(ApplicationTy { ctor, parameters }) if ctor == &std_result_ctor => parameters,
            _ => return,
        };

        if params.len() == 2 && &params[0] == &mismatch.actual {
            let source_map = self.func.body_source_map(db);

            if let Some(source_ptr) = source_map.expr_syntax(id) {
                if let Some(expr) = source_ptr.value.a() {
                    self.sink.push(MissingOkInTailExpr { file: source_ptr.file_id, expr });
                }
            }
        }
    }
}