rust-analyzer/crates/ra_hir/src/expr/validation.rs
2019-09-02 21:23:19 +03:00

146 lines
4.6 KiB
Rust

use std::sync::Arc;
use ra_syntax::ast::{self, AstNode};
use rustc_hash::FxHashSet;
use super::{Expr, ExprId, RecordLitField};
use crate::{
adt::AdtDef,
diagnostics::{DiagnosticSink, MissingFields, MissingOkInTailExpr},
expr::AstPtr,
name,
path::{PathKind, PathSegment},
ty::{ApplicationTy, InferenceResult, Ty, TypeCtor},
Function, HasSource, HirDatabase, ModuleDef, Name, Path, PerNs, Resolution,
};
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((AdtDef::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);
let file_id = self.func.source(db).file_id;
let parse = db.parse(file_id.original_file(db));
let source_file = parse.tree();
if let Some(field_list_node) = source_map
.expr_syntax(id)
.and_then(|ptr| ptr.a())
.map(|ptr| ptr.to_node(source_file.syntax()))
.and_then(|expr| match expr {
ast::Expr::RecordLit(it) => Some(it),
_ => None,
})
.and_then(|lit| lit.record_field_list())
{
let field_list_ptr = AstPtr::new(&field_list_node);
self.sink.push(MissingFields {
file: file_id,
field_list: field_list_ptr,
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 = Path {
kind: PathKind::Abs,
segments: vec![
PathSegment { name: name::STD, args_and_bindings: None },
PathSegment { name: name::RESULT_MOD, args_and_bindings: None },
PathSegment { name: name::RESULT_TYPE, args_and_bindings: None },
],
};
let resolver = self.func.resolver(db);
let std_result_enum =
match resolver.resolve_path_segments(db, &std_result_path).into_fully_resolved() {
PerNs { types: Some(Resolution::Def(ModuleDef::Enum(e))), .. } => e,
_ => return,
};
let std_result_ctor = TypeCtor::Adt(AdtDef::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);
let file_id = self.func.source(db).file_id;
if let Some(expr) = source_map.expr_syntax(id).and_then(|n| n.a()) {
self.sink.push(MissingOkInTailExpr { file: file_id, expr });
}
}
}
}