use crate::{map_unit_fn::OPTION_MAP_UNIT_FN, matches::MATCH_AS_REF};
use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::higher;
use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
use clippy_utils::ty::{is_type_diagnostic_item, peel_mid_ty_refs_is_mutable};
use clippy_utils::{
use rustc_ast::util::parser::PREC_POSTFIX;
use rustc_errors::Applicability;
use rustc_hir::LangItem::{OptionNone, OptionSome};
-use rustc_hir::{Arm, BindingAnnotation, Block, Expr, ExprKind, HirId, MatchSource, Mutability, Pat, PatKind};
+use rustc_hir::{Arm, BindingAnnotation, Block, Expr, ExprKind, HirId, Mutability, Pat, PatKind};
use rustc_lint::{LateContext, LateLintPass, LintContext};
use rustc_middle::lint::in_external_macro;
use rustc_session::{declare_lint_pass, declare_tool_lint};
impl LateLintPass<'_> for ManualMap {
#[allow(clippy::too_many_lines)]
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
- if let ExprKind::Match(
- scrutinee,
- [arm1 @ Arm { guard: None, .. }, arm2 @ Arm { guard: None, .. }],
- match_kind,
- ) = expr.kind
+ if let Some(higher::IfLet {
+ let_pat,
+ let_expr,
+ if_then,
+ if_else: Some(if_else),
+ }) = higher::IfLet::hir(cx, expr)
{
- if in_external_macro(cx.sess(), expr.span) || in_constant(cx, expr.hir_id) {
- return;
- }
+ manage_lint(cx, expr, (&let_pat.kind, if_then), (&PatKind::Wild, if_else), let_expr);
+ }
- let (scrutinee_ty, ty_ref_count, ty_mutability) =
- peel_mid_ty_refs_is_mutable(cx.typeck_results().expr_ty(scrutinee));
- if !(is_type_diagnostic_item(cx, scrutinee_ty, sym::option_type)
- && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::option_type))
- {
- return;
- }
+ if let ExprKind::Match(scrutinee, [then @ Arm { guard: None, .. }, r#else @ Arm { guard: None, .. }], _) =
+ expr.kind
+ {
+ manage_lint(
+ cx,
+ expr,
+ (&then.pat.kind, then.body),
+ (&r#else.pat.kind, r#else.body),
+ scrutinee,
+ );
+ }
+ }
+}
- let expr_ctxt = expr.span.ctxt();
- let (some_expr, some_pat, pat_ref_count, is_wild_none) = match (
- try_parse_pattern(cx, arm1.pat, expr_ctxt),
- try_parse_pattern(cx, arm2.pat, expr_ctxt),
- ) {
- (Some(OptionPat::Wild), Some(OptionPat::Some { pattern, ref_count }))
- if is_none_expr(cx, arm1.body) =>
- {
- (arm2.body, pattern, ref_count, true)
- },
- (Some(OptionPat::None), Some(OptionPat::Some { pattern, ref_count }))
- if is_none_expr(cx, arm1.body) =>
- {
- (arm2.body, pattern, ref_count, false)
- },
- (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::Wild))
- if is_none_expr(cx, arm2.body) =>
- {
- (arm1.body, pattern, ref_count, true)
- },
- (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::None))
- if is_none_expr(cx, arm2.body) =>
- {
- (arm1.body, pattern, ref_count, false)
- },
- _ => return,
- };
+fn manage_lint<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx Expr<'_>,
+ then: (&'tcx PatKind<'_>, &'tcx Expr<'_>),
+ r#else: (&'tcx PatKind<'_>, &'tcx Expr<'_>),
+ scrut: &'tcx Expr<'_>,
+) {
+ if in_external_macro(cx.sess(), expr.span) || in_constant(cx, expr.hir_id) {
+ return;
+ }
- // Top level or patterns aren't allowed in closures.
- if matches!(some_pat.kind, PatKind::Or(_)) {
- return;
- }
+ let (scrutinee_ty, ty_ref_count, ty_mutability) = peel_mid_ty_refs_is_mutable(cx.typeck_results().expr_ty(scrut));
+ if !(is_type_diagnostic_item(cx, scrutinee_ty, sym::option_type)
+ && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::option_type))
+ {
+ return;
+ }
- let some_expr = match get_some_expr(cx, some_expr, expr_ctxt) {
- Some(expr) => expr,
- None => return,
- };
+ let (then_pat, then_expr) = then;
+ let (else_pat, else_expr) = r#else;
- // These two lints will go back and forth with each other.
- if cx.typeck_results().expr_ty(some_expr) == cx.tcx.types.unit
- && !is_lint_allowed(cx, OPTION_MAP_UNIT_FN, expr.hir_id)
- {
- return;
- }
+ let expr_ctxt = expr.span.ctxt();
+ let (some_expr, some_pat, pat_ref_count, is_wild_none) = match (
+ try_parse_pattern(cx, then_pat, expr_ctxt),
+ try_parse_pattern(cx, else_pat, expr_ctxt),
+ ) {
+ (Some(OptionPat::Wild), Some(OptionPat::Some { pattern, ref_count })) if is_none_expr(cx, then_expr) => {
+ (else_expr, pattern, ref_count, true)
+ },
+ (Some(OptionPat::None), Some(OptionPat::Some { pattern, ref_count })) if is_none_expr(cx, then_expr) => {
+ (else_expr, pattern, ref_count, false)
+ },
+ (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::Wild)) if is_none_expr(cx, else_expr) => {
+ (then_expr, pattern, ref_count, true)
+ },
+ (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::None)) if is_none_expr(cx, else_expr) => {
+ (then_expr, pattern, ref_count, false)
+ },
+ _ => return,
+ };
- // `map` won't perform any adjustments.
- if !cx.typeck_results().expr_adjustments(some_expr).is_empty() {
- return;
- }
+ // Top level or patterns aren't allowed in closures.
+ if matches!(some_pat.kind, PatKind::Or(_)) {
+ return;
+ }
- if !can_move_expr_to_closure(cx, some_expr) {
- return;
- }
+ let some_expr = match get_some_expr(cx, some_expr, expr_ctxt) {
+ Some(expr) => expr,
+ None => return,
+ };
- // Determine which binding mode to use.
- let explicit_ref = some_pat.contains_explicit_ref_binding();
- let binding_ref = explicit_ref.or_else(|| (ty_ref_count != pat_ref_count).then(|| ty_mutability));
+ if cx.typeck_results().expr_ty(some_expr) == cx.tcx.types.unit && !is_lint_allowed(cx, OPTION_MAP_UNIT_FN, expr.hir_id) {
+ return;
+ }
- let as_ref_str = match binding_ref {
- Some(Mutability::Mut) => ".as_mut()",
- Some(Mutability::Not) => ".as_ref()",
- None => "",
- };
+ // `map` won't perform any adjustments.
+ if !cx.typeck_results().expr_adjustments(some_expr).is_empty() {
+ return;
+ }
- let mut app = Applicability::MachineApplicable;
+ if !can_move_expr_to_closure(cx, some_expr) {
+ return;
+ }
- // Remove address-of expressions from the scrutinee. Either `as_ref` will be called, or
- // it's being passed by value.
- let scrutinee = peel_hir_expr_refs(scrutinee).0;
- let (scrutinee_str, _) = snippet_with_context(cx, scrutinee.span, expr_ctxt, "..", &mut app);
- let scrutinee_str =
- if scrutinee.span.ctxt() == expr.span.ctxt() && scrutinee.precedence().order() < PREC_POSTFIX {
- format!("({})", scrutinee_str)
- } else {
- scrutinee_str.into()
- };
+ // Determine which binding mode to use.
+ let explicit_ref = some_pat.contains_explicit_ref_binding();
+ let binding_ref = explicit_ref.or_else(|| (ty_ref_count != pat_ref_count).then(|| ty_mutability));
+
+ let as_ref_str = match binding_ref {
+ Some(Mutability::Mut) => ".as_mut()",
+ Some(Mutability::Not) => ".as_ref()",
+ None => "",
+ };
+
+ let mut app = Applicability::MachineApplicable;
- let body_str = if let PatKind::Binding(annotation, id, some_binding, None) = some_pat.kind {
- match can_pass_as_func(cx, id, some_expr) {
- Some(func) if func.span.ctxt() == some_expr.span.ctxt() => {
- snippet_with_applicability(cx, func.span, "..", &mut app).into_owned()
- },
- _ => {
- if path_to_local_id(some_expr, id)
- && !is_lint_allowed(cx, MATCH_AS_REF, expr.hir_id)
- && binding_ref.is_some()
- {
- return;
- }
+ // Remove address-of expressions from the scrutinee. Either `as_ref` will be called, or
+ // it's being passed by value.
+ let scrutinee = peel_hir_expr_refs(scrut).0;
+ let (scrutinee_str, _) = snippet_with_context(cx, scrutinee.span, expr_ctxt, "..", &mut app);
+ let scrutinee_str = if scrutinee.span.ctxt() == expr.span.ctxt() && scrutinee.precedence().order() < PREC_POSTFIX {
+ format!("({})", scrutinee_str)
+ } else {
+ scrutinee_str.into()
+ };
- // `ref` and `ref mut` annotations were handled earlier.
- let annotation = if matches!(annotation, BindingAnnotation::Mutable) {
- "mut "
- } else {
- ""
- };
- format!(
- "|{}{}| {}",
- annotation,
- some_binding,
- snippet_with_context(cx, some_expr.span, expr_ctxt, "..", &mut app).0
- )
- },
+ let body_str = if let PatKind::Binding(annotation, id, some_binding, None) = some_pat.kind {
+ match can_pass_as_func(cx, id, some_expr) {
+ Some(func) if func.span.ctxt() == some_expr.span.ctxt() => {
+ snippet_with_applicability(cx, func.span, "..", &mut app).into_owned()
+ },
+ _ => {
+ if path_to_local_id(some_expr, id)
+ && !is_lint_allowed(cx, MATCH_AS_REF, expr.hir_id)
+ && binding_ref.is_some()
+ {
+ return;
}
- } else if !is_wild_none && explicit_ref.is_none() {
- // TODO: handle explicit reference annotations.
+
+ // `ref` and `ref mut` annotations were handled earlier.
+ let annotation = if matches!(annotation, BindingAnnotation::Mutable) {
+ "mut "
+ } else {
+ ""
+ };
format!(
- "|{}| {}",
- snippet_with_context(cx, some_pat.span, expr_ctxt, "..", &mut app).0,
+ "|{}{}| {}",
+ annotation,
+ some_binding,
snippet_with_context(cx, some_expr.span, expr_ctxt, "..", &mut app).0
)
- } else {
- // Refutable bindings and mixed reference annotations can't be handled by `map`.
- return;
- };
-
- span_lint_and_sugg(
- cx,
- MANUAL_MAP,
- expr.span,
- "manual implementation of `Option::map`",
- "try this",
- if matches!(match_kind, MatchSource::IfLetDesugar { .. }) && is_else_clause(cx.tcx, expr) {
- format!("{{ {}{}.map({}) }}", scrutinee_str, as_ref_str, body_str)
- } else {
- format!("{}{}.map({})", scrutinee_str, as_ref_str, body_str)
- },
- app,
- );
+ },
}
- }
+ } else if !is_wild_none && explicit_ref.is_none() {
+ // TODO: handle explicit reference annotations.
+ format!(
+ "|{}| {}",
+ snippet_with_context(cx, some_pat.span, expr_ctxt, "..", &mut app).0,
+ snippet_with_context(cx, some_expr.span, expr_ctxt, "..", &mut app).0
+ )
+ } else {
+ // Refutable bindings and mixed reference annotations can't be handled by `map`.
+ return;
+ };
+
+ span_lint_and_sugg(
+ cx,
+ MANUAL_MAP,
+ expr.span,
+ "manual implementation of `Option::map`",
+ "try this",
+ if is_else_clause(cx.tcx, expr) {
+ format!("{{ {}{}.map({}) }}", scrutinee_str, as_ref_str, body_str)
+ } else {
+ format!("{}{}.map({})", scrutinee_str, as_ref_str, body_str)
+ },
+ app,
+ );
}
// Checks whether the expression could be passed as a function, or whether a closure is needed.
fn can_pass_as_func(cx: &LateContext<'tcx>, binding: HirId, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
match expr.kind {
ExprKind::Call(func, [arg])
- if path_to_local_id(arg, binding) && cx.typeck_results().expr_adjustments(arg).is_empty() =>
+ if path_to_local_id (arg, binding) && cx.typeck_results().expr_adjustments(arg).is_empty() =>
{
Some(func)
},
// Try to parse into a recognized `Option` pattern.
// i.e. `_`, `None`, `Some(..)`, or a reference to any of those.
-fn try_parse_pattern(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, ctxt: SyntaxContext) -> Option<OptionPat<'tcx>> {
- fn f(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, ref_count: usize, ctxt: SyntaxContext) -> Option<OptionPat<'tcx>> {
- match pat.kind {
+fn try_parse_pattern(
+ cx: &LateContext<'tcx>,
+ pat_kind: &'tcx PatKind<'_>,
+ ctxt: SyntaxContext,
+) -> Option<OptionPat<'tcx>> {
+ fn f(
+ cx: &LateContext<'tcx>,
+ pat_kind: &'tcx PatKind<'_>,
+ ref_count: usize,
+ ctxt: SyntaxContext,
+ ) -> Option<OptionPat<'tcx>> {
+ match pat_kind {
PatKind::Wild => Some(OptionPat::Wild),
- PatKind::Ref(pat, _) => f(cx, pat, ref_count + 1, ctxt),
+ PatKind::Ref(ref_pat, _) => f(cx, &ref_pat.kind, ref_count + 1, ctxt),
PatKind::Path(ref qpath) if is_lang_ctor(cx, qpath, OptionNone) => Some(OptionPat::None),
- PatKind::TupleStruct(ref qpath, [pattern], _)
- if is_lang_ctor(cx, qpath, OptionSome) && pat.span.ctxt() == ctxt =>
- {
+ PatKind::TupleStruct(ref qpath, [pattern], _) if is_lang_ctor(cx, qpath, OptionSome) => {
Some(OptionPat::Some { pattern, ref_count })
},
_ => None,
}
}
- f(cx, pat, 0, ctxt)
+ f(cx, pat_kind, 0, ctxt)
}
// Checks for an expression wrapped by the `Some` constructor. Returns the contained expression.
projects / rust.git / blobdiff