mirror of
https://github.com/rust-lang/rust-analyzer
synced 2025-01-08 19:28:54 +00:00
619 lines
18 KiB
Rust
619 lines
18 KiB
Rust
//! FIXME: write short doc here
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use std::sync::Arc;
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use hir_def::{expr::Statement, path::path, resolver::HasResolver, AdtId, DefWithBodyId};
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use hir_expand::diagnostics::DiagnosticSink;
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use rustc_hash::FxHashSet;
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use syntax::{ast, AstPtr};
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use crate::{
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db::HirDatabase,
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diagnostics::{
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match_check::{is_useful, MatchCheckCtx, Matrix, PatStack, Usefulness},
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MismatchedArgCount, MissingFields, MissingMatchArms, MissingOkInTailExpr, MissingPatFields,
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RemoveThisSemicolon,
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},
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utils::variant_data,
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ApplicationTy, InferenceResult, Ty, TypeCtor,
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};
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pub(crate) use hir_def::{
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body::{Body, BodySourceMap},
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expr::{Expr, ExprId, MatchArm, Pat, PatId},
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LocalFieldId, VariantId,
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};
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pub(super) struct ExprValidator<'a, 'b: 'a> {
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owner: DefWithBodyId,
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infer: Arc<InferenceResult>,
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sink: &'a mut DiagnosticSink<'b>,
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}
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impl<'a, 'b> ExprValidator<'a, 'b> {
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pub(super) fn new(
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owner: DefWithBodyId,
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infer: Arc<InferenceResult>,
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sink: &'a mut DiagnosticSink<'b>,
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) -> ExprValidator<'a, 'b> {
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ExprValidator { owner, infer, sink }
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}
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pub(super) fn validate_body(&mut self, db: &dyn HirDatabase) {
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let body = db.body(self.owner.into());
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for (id, expr) in body.exprs.iter() {
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if let Some((variant_def, missed_fields, true)) =
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record_literal_missing_fields(db, &self.infer, id, expr)
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{
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self.create_record_literal_missing_fields_diagnostic(
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id,
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db,
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variant_def,
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missed_fields,
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);
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}
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match expr {
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Expr::Match { expr, arms } => {
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self.validate_match(id, *expr, arms, db, self.infer.clone());
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}
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Expr::Call { .. } | Expr::MethodCall { .. } => {
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self.validate_call(db, id, expr);
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}
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_ => {}
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}
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}
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for (id, pat) in body.pats.iter() {
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if let Some((variant_def, missed_fields, true)) =
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record_pattern_missing_fields(db, &self.infer, id, pat)
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{
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self.create_record_pattern_missing_fields_diagnostic(
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id,
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db,
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variant_def,
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missed_fields,
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);
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}
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}
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let body_expr = &body[body.body_expr];
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if let Expr::Block { statements, tail, .. } = body_expr {
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if let Some(t) = tail {
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self.validate_results_in_tail_expr(body.body_expr, *t, db);
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} else if let Some(Statement::Expr(id)) = statements.last() {
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self.validate_missing_tail_expr(body.body_expr, *id, db);
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}
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}
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}
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fn create_record_literal_missing_fields_diagnostic(
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&mut self,
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id: ExprId,
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db: &dyn HirDatabase,
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variant_def: VariantId,
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missed_fields: Vec<LocalFieldId>,
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) {
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// XXX: only look at source_map if we do have missing fields
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let (_, source_map) = db.body_with_source_map(self.owner.into());
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if let Ok(source_ptr) = source_map.expr_syntax(id) {
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let root = source_ptr.file_syntax(db.upcast());
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if let ast::Expr::RecordExpr(record_expr) = &source_ptr.value.to_node(&root) {
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if let Some(_) = record_expr.record_expr_field_list() {
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let variant_data = variant_data(db.upcast(), variant_def);
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let missed_fields = missed_fields
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.into_iter()
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.map(|idx| variant_data.fields()[idx].name.clone())
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.collect();
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self.sink.push(MissingFields {
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file: source_ptr.file_id,
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field_list_parent: AstPtr::new(&record_expr),
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field_list_parent_path: record_expr.path().map(|path| AstPtr::new(&path)),
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missed_fields,
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})
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}
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}
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}
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}
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fn create_record_pattern_missing_fields_diagnostic(
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&mut self,
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id: PatId,
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db: &dyn HirDatabase,
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variant_def: VariantId,
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missed_fields: Vec<LocalFieldId>,
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) {
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// XXX: only look at source_map if we do have missing fields
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let (_, source_map) = db.body_with_source_map(self.owner.into());
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if let Ok(source_ptr) = source_map.pat_syntax(id) {
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if let Some(expr) = source_ptr.value.as_ref().left() {
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let root = source_ptr.file_syntax(db.upcast());
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if let ast::Pat::RecordPat(record_pat) = expr.to_node(&root) {
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if let Some(_) = record_pat.record_pat_field_list() {
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let variant_data = variant_data(db.upcast(), variant_def);
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let missed_fields = missed_fields
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.into_iter()
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.map(|idx| variant_data.fields()[idx].name.clone())
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.collect();
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self.sink.push(MissingPatFields {
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file: source_ptr.file_id,
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field_list_parent: AstPtr::new(&record_pat),
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field_list_parent_path: record_pat
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.path()
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.map(|path| AstPtr::new(&path)),
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missed_fields,
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})
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}
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}
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}
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}
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}
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fn validate_call(&mut self, db: &dyn HirDatabase, call_id: ExprId, expr: &Expr) -> Option<()> {
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// Check that the number of arguments matches the number of parameters.
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// FIXME: Due to shortcomings in the current type system implementation, only emit this
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// diagnostic if there are no type mismatches in the containing function.
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if self.infer.type_mismatches.iter().next().is_some() {
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return None;
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}
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let is_method_call = matches!(expr, Expr::MethodCall { .. });
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let (sig, args) = match expr {
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Expr::Call { callee, args } => {
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let callee = &self.infer.type_of_expr[*callee];
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let sig = callee.callable_sig(db)?;
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(sig, args.clone())
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}
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Expr::MethodCall { receiver, args, .. } => {
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let mut args = args.clone();
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args.insert(0, *receiver);
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let receiver = &self.infer.type_of_expr[*receiver];
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if receiver.strip_references().is_unknown() {
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// if the receiver is of unknown type, it's very likely we
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// don't know enough to correctly resolve the method call.
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// This is kind of a band-aid for #6975.
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return None;
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}
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// FIXME: note that we erase information about substs here. This
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// is not right, but, luckily, doesn't matter as we care only
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// about the number of params
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let callee = self.infer.method_resolution(call_id)?;
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let sig = db.callable_item_signature(callee.into()).value;
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(sig, args)
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}
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_ => return None,
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};
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if sig.is_varargs {
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return None;
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}
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let params = sig.params();
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let mut param_count = params.len();
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let mut arg_count = args.len();
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if arg_count != param_count {
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let (_, source_map) = db.body_with_source_map(self.owner.into());
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if let Ok(source_ptr) = source_map.expr_syntax(call_id) {
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if is_method_call {
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param_count -= 1;
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arg_count -= 1;
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}
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self.sink.push(MismatchedArgCount {
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file: source_ptr.file_id,
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call_expr: source_ptr.value,
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expected: param_count,
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found: arg_count,
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});
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}
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}
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None
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}
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fn validate_match(
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&mut self,
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id: ExprId,
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match_expr: ExprId,
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arms: &[MatchArm],
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db: &dyn HirDatabase,
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infer: Arc<InferenceResult>,
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) {
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let (body, source_map): (Arc<Body>, Arc<BodySourceMap>) =
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db.body_with_source_map(self.owner.into());
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let match_expr_ty = match infer.type_of_expr.get(match_expr) {
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// If we can't resolve the type of the match expression
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// we cannot perform exhaustiveness checks.
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None | Some(Ty::Unknown) => return,
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Some(ty) => ty,
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};
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let cx = MatchCheckCtx { match_expr, body, infer: infer.clone(), db };
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let pats = arms.iter().map(|arm| arm.pat);
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let mut seen = Matrix::empty();
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for pat in pats {
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if let Some(pat_ty) = infer.type_of_pat.get(pat) {
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// We only include patterns whose type matches the type
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// of the match expression. If we had a InvalidMatchArmPattern
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// diagnostic or similar we could raise that in an else
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// block here.
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//
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// When comparing the types, we also have to consider that rustc
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// will automatically de-reference the match expression type if
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// necessary.
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//
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// FIXME we should use the type checker for this.
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if pat_ty == match_expr_ty
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|| match_expr_ty
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.as_reference()
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.map(|(match_expr_ty, _)| match_expr_ty == pat_ty)
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.unwrap_or(false)
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{
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// If we had a NotUsefulMatchArm diagnostic, we could
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// check the usefulness of each pattern as we added it
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// to the matrix here.
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let v = PatStack::from_pattern(pat);
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seen.push(&cx, v);
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continue;
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}
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}
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// If we can't resolve the type of a pattern, or the pattern type doesn't
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// fit the match expression, we skip this diagnostic. Skipping the entire
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// diagnostic rather than just not including this match arm is preferred
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// to avoid the chance of false positives.
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return;
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}
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match is_useful(&cx, &seen, &PatStack::from_wild()) {
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Ok(Usefulness::Useful) => (),
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// if a wildcard pattern is not useful, then all patterns are covered
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Ok(Usefulness::NotUseful) => return,
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// this path is for unimplemented checks, so we err on the side of not
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// reporting any errors
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_ => return,
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}
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if let Ok(source_ptr) = source_map.expr_syntax(id) {
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let root = source_ptr.file_syntax(db.upcast());
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if let ast::Expr::MatchExpr(match_expr) = &source_ptr.value.to_node(&root) {
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if let (Some(match_expr), Some(arms)) =
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(match_expr.expr(), match_expr.match_arm_list())
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{
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self.sink.push(MissingMatchArms {
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file: source_ptr.file_id,
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match_expr: AstPtr::new(&match_expr),
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arms: AstPtr::new(&arms),
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})
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}
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}
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}
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}
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fn validate_results_in_tail_expr(&mut self, body_id: ExprId, id: ExprId, db: &dyn HirDatabase) {
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// the mismatch will be on the whole block currently
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let mismatch = match self.infer.type_mismatch_for_expr(body_id) {
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Some(m) => m,
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None => return,
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};
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let core_result_path = path![core::result::Result];
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let resolver = self.owner.resolver(db.upcast());
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let core_result_enum = match resolver.resolve_known_enum(db.upcast(), &core_result_path) {
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Some(it) => it,
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_ => return,
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};
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let core_result_ctor = TypeCtor::Adt(AdtId::EnumId(core_result_enum));
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let params = match &mismatch.expected {
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Ty::Apply(ApplicationTy { ctor, parameters }) if ctor == &core_result_ctor => {
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parameters
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}
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_ => return,
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};
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if params.len() == 2 && params[0] == mismatch.actual {
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let (_, source_map) = db.body_with_source_map(self.owner.into());
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if let Ok(source_ptr) = source_map.expr_syntax(id) {
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self.sink
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.push(MissingOkInTailExpr { file: source_ptr.file_id, expr: source_ptr.value });
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}
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}
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}
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fn validate_missing_tail_expr(
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&mut self,
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body_id: ExprId,
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possible_tail_id: ExprId,
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db: &dyn HirDatabase,
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) {
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let mismatch = match self.infer.type_mismatch_for_expr(body_id) {
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Some(m) => m,
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None => return,
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};
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let possible_tail_ty = match self.infer.type_of_expr.get(possible_tail_id) {
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Some(ty) => ty,
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None => return,
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};
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if mismatch.actual != Ty::unit() || mismatch.expected != *possible_tail_ty {
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return;
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}
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let (_, source_map) = db.body_with_source_map(self.owner.into());
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if let Ok(source_ptr) = source_map.expr_syntax(possible_tail_id) {
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self.sink
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.push(RemoveThisSemicolon { file: source_ptr.file_id, expr: source_ptr.value });
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}
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}
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}
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pub fn record_literal_missing_fields(
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db: &dyn HirDatabase,
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infer: &InferenceResult,
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id: ExprId,
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expr: &Expr,
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) -> Option<(VariantId, Vec<LocalFieldId>, /*exhaustive*/ bool)> {
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let (fields, exhausitve) = match expr {
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Expr::RecordLit { path: _, fields, spread } => (fields, spread.is_none()),
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_ => return None,
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};
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let variant_def = infer.variant_resolution_for_expr(id)?;
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if let VariantId::UnionId(_) = variant_def {
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return None;
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}
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let variant_data = variant_data(db.upcast(), variant_def);
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let specified_fields: FxHashSet<_> = fields.iter().map(|f| &f.name).collect();
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let missed_fields: Vec<LocalFieldId> = variant_data
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.fields()
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.iter()
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.filter_map(|(f, d)| if specified_fields.contains(&d.name) { None } else { Some(f) })
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.collect();
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if missed_fields.is_empty() {
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return None;
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}
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Some((variant_def, missed_fields, exhausitve))
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}
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pub fn record_pattern_missing_fields(
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db: &dyn HirDatabase,
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infer: &InferenceResult,
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id: PatId,
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pat: &Pat,
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) -> Option<(VariantId, Vec<LocalFieldId>, /*exhaustive*/ bool)> {
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let (fields, exhaustive) = match pat {
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Pat::Record { path: _, args, ellipsis } => (args, !ellipsis),
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_ => return None,
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};
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let variant_def = infer.variant_resolution_for_pat(id)?;
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if let VariantId::UnionId(_) = variant_def {
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return None;
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}
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let variant_data = variant_data(db.upcast(), variant_def);
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let specified_fields: FxHashSet<_> = fields.iter().map(|f| &f.name).collect();
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let missed_fields: Vec<LocalFieldId> = variant_data
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.fields()
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.iter()
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.filter_map(|(f, d)| if specified_fields.contains(&d.name) { None } else { Some(f) })
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.collect();
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if missed_fields.is_empty() {
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return None;
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}
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Some((variant_def, missed_fields, exhaustive))
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}
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#[cfg(test)]
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mod tests {
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use crate::diagnostics::tests::check_diagnostics;
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#[test]
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fn simple_free_fn_zero() {
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check_diagnostics(
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r#"
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fn zero() {}
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fn f() { zero(1); }
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//^^^^^^^ Expected 0 arguments, found 1
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"#,
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);
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check_diagnostics(
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r#"
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fn zero() {}
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fn f() { zero(); }
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"#,
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);
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}
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#[test]
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fn simple_free_fn_one() {
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check_diagnostics(
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r#"
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fn one(arg: u8) {}
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fn f() { one(); }
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//^^^^^ Expected 1 argument, found 0
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"#,
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);
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check_diagnostics(
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r#"
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fn one(arg: u8) {}
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fn f() { one(1); }
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"#,
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);
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}
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#[test]
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fn method_as_fn() {
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check_diagnostics(
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r#"
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struct S;
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impl S { fn method(&self) {} }
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fn f() {
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S::method();
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} //^^^^^^^^^^^ Expected 1 argument, found 0
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"#,
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);
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check_diagnostics(
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r#"
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struct S;
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impl S { fn method(&self) {} }
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fn f() {
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S::method(&S);
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S.method();
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}
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"#,
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);
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}
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#[test]
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fn method_with_arg() {
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check_diagnostics(
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r#"
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struct S;
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impl S { fn method(&self, arg: u8) {} }
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fn f() {
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S.method();
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} //^^^^^^^^^^ Expected 1 argument, found 0
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"#,
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);
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check_diagnostics(
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r#"
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struct S;
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impl S { fn method(&self, arg: u8) {} }
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fn f() {
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S::method(&S, 0);
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S.method(1);
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}
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"#,
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);
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}
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#[test]
|
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fn method_unknown_receiver() {
|
|
// note: this is incorrect code, so there might be errors on this in the
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|
// future, but we shouldn't emit an argument count diagnostic here
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|
check_diagnostics(
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r#"
|
|
trait Foo { fn method(&self, arg: usize) {} }
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|
|
fn f() {
|
|
let x;
|
|
x.method();
|
|
}
|
|
"#,
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn tuple_struct() {
|
|
check_diagnostics(
|
|
r#"
|
|
struct Tup(u8, u16);
|
|
fn f() {
|
|
Tup(0);
|
|
} //^^^^^^ Expected 2 arguments, found 1
|
|
"#,
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn enum_variant() {
|
|
check_diagnostics(
|
|
r#"
|
|
enum En { Variant(u8, u16), }
|
|
fn f() {
|
|
En::Variant(0);
|
|
} //^^^^^^^^^^^^^^ Expected 2 arguments, found 1
|
|
"#,
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn enum_variant_type_macro() {
|
|
check_diagnostics(
|
|
r#"
|
|
macro_rules! Type {
|
|
() => { u32 };
|
|
}
|
|
enum Foo {
|
|
Bar(Type![])
|
|
}
|
|
impl Foo {
|
|
fn new() {
|
|
Foo::Bar(0);
|
|
Foo::Bar(0, 1);
|
|
//^^^^^^^^^^^^^^ Expected 1 argument, found 2
|
|
Foo::Bar();
|
|
//^^^^^^^^^^ Expected 1 argument, found 0
|
|
}
|
|
}
|
|
"#,
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn varargs() {
|
|
check_diagnostics(
|
|
r#"
|
|
extern "C" {
|
|
fn fixed(fixed: u8);
|
|
fn varargs(fixed: u8, ...);
|
|
fn varargs2(...);
|
|
}
|
|
|
|
fn f() {
|
|
unsafe {
|
|
fixed(0);
|
|
fixed(0, 1);
|
|
//^^^^^^^^^^^ Expected 1 argument, found 2
|
|
varargs(0);
|
|
varargs(0, 1);
|
|
varargs2();
|
|
varargs2(0);
|
|
varargs2(0, 1);
|
|
}
|
|
}
|
|
"#,
|
|
)
|
|
}
|
|
|
|
#[test]
|
|
fn arg_count_lambda() {
|
|
check_diagnostics(
|
|
r#"
|
|
fn main() {
|
|
let f = |()| ();
|
|
f();
|
|
//^^^ Expected 1 argument, found 0
|
|
f(());
|
|
f((), ());
|
|
//^^^^^^^^^ Expected 1 argument, found 2
|
|
}
|
|
"#,
|
|
)
|
|
}
|
|
}
|