summaryrefslogtreecommitdiffstats
path: root/src/tools/clippy/clippy_lints/src/matches/manual_map.rs
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--src/tools/clippy/clippy_lints/src/matches/manual_map.rs318
1 files changed, 64 insertions, 254 deletions
diff --git a/src/tools/clippy/clippy_lints/src/matches/manual_map.rs b/src/tools/clippy/clippy_lints/src/matches/manual_map.rs
index b0198e856..aaba23967 100644
--- a/src/tools/clippy/clippy_lints/src/matches/manual_map.rs
+++ b/src/tools/clippy/clippy_lints/src/matches/manual_map.rs
@@ -1,22 +1,13 @@
-use crate::{map_unit_fn::OPTION_MAP_UNIT_FN, matches::MATCH_AS_REF};
+use super::manual_utils::{check_with, SomeExpr};
+use super::MANUAL_MAP;
use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::source::{snippet_with_applicability, snippet_with_context};
-use clippy_utils::ty::{is_type_diagnostic_item, peel_mid_ty_refs_is_mutable, type_is_unsafe_function};
-use clippy_utils::{
- can_move_expr_to_closure, is_else_clause, is_lang_ctor, is_lint_allowed, path_to_local_id, peel_blocks,
- peel_hir_expr_refs, peel_hir_expr_while, CaptureKind,
-};
-use rustc_ast::util::parser::PREC_POSTFIX;
-use rustc_errors::Applicability;
-use rustc_hir::LangItem::{OptionNone, OptionSome};
-use rustc_hir::{
- def::Res, Arm, BindingAnnotation, Block, BlockCheckMode, Expr, ExprKind, HirId, Mutability, Pat, PatKind, Path,
- QPath, UnsafeSource,
-};
-use rustc_lint::LateContext;
-use rustc_span::{sym, SyntaxContext};
-use super::MANUAL_MAP;
+use clippy_utils::{is_res_lang_ctor, path_res};
+
+use rustc_hir::LangItem::OptionSome;
+use rustc_hir::{Arm, Block, BlockCheckMode, Expr, ExprKind, Pat, UnsafeSource};
+use rustc_lint::LateContext;
+use rustc_span::SyntaxContext;
pub(super) fn check_match<'tcx>(
cx: &LateContext<'tcx>,
@@ -43,7 +34,6 @@ pub(super) fn check_if_let<'tcx>(
check(cx, expr, let_expr, let_pat, then_expr, None, else_expr);
}
-#[expect(clippy::too_many_lines)]
fn check<'tcx>(
cx: &LateContext<'tcx>,
expr: &'tcx Expr<'_>,
@@ -53,254 +43,74 @@ fn check<'tcx>(
else_pat: Option<&'tcx Pat<'_>>,
else_body: &'tcx 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)
- && is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::Option))
- {
- 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),
- else_pat.map_or(Some(OptionPat::Wild), |p| try_parse_pattern(cx, p, expr_ctxt)),
+ if let Some(sugg_info) = check_with(
+ cx,
+ expr,
+ scrutinee,
+ then_pat,
+ then_body,
+ else_pat,
+ else_body,
+ get_some_expr,
) {
- (Some(OptionPat::Wild), Some(OptionPat::Some { pattern, ref_count })) if is_none_expr(cx, then_body) => {
- (else_body, pattern, ref_count, true)
- },
- (Some(OptionPat::None), Some(OptionPat::Some { pattern, ref_count })) if is_none_expr(cx, then_body) => {
- (else_body, pattern, ref_count, false)
- },
- (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::Wild)) if is_none_expr(cx, else_body) => {
- (then_body, pattern, ref_count, true)
- },
- (Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::None)) if is_none_expr(cx, else_body) => {
- (then_body, pattern, ref_count, false)
- },
- _ => return,
- };
-
- // Top level or patterns aren't allowed in closures.
- if matches!(some_pat.kind, PatKind::Or(_)) {
- return;
- }
-
- let some_expr = match get_some_expr(cx, some_expr, false, expr_ctxt) {
- Some(expr) => expr,
- None => return,
- };
-
- // These two lints will go back and forth with each other.
- if cx.typeck_results().expr_ty(some_expr.expr) == cx.tcx.types.unit
- && !is_lint_allowed(cx, OPTION_MAP_UNIT_FN, expr.hir_id)
- {
- return;
- }
-
- // `map` won't perform any adjustments.
- if !cx.typeck_results().expr_adjustments(some_expr.expr).is_empty() {
- 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_some(ty_mutability));
-
- let as_ref_str = match binding_ref {
- Some(Mutability::Mut) => ".as_mut()",
- Some(Mutability::Not) => ".as_ref()",
- None => "",
- };
-
- match can_move_expr_to_closure(cx, some_expr.expr) {
- Some(captures) => {
- // Check if captures the closure will need conflict with borrows made in the scrutinee.
- // TODO: check all the references made in the scrutinee expression. This will require interacting
- // with the borrow checker. Currently only `<local>[.<field>]*` is checked for.
- if let Some(binding_ref_mutability) = binding_ref {
- let e = peel_hir_expr_while(scrutinee, |e| match e.kind {
- ExprKind::Field(e, _) | ExprKind::AddrOf(_, _, e) => Some(e),
- _ => None,
- });
- if let ExprKind::Path(QPath::Resolved(None, Path { res: Res::Local(l), .. })) = e.kind {
- match captures.get(l) {
- Some(CaptureKind::Value | CaptureKind::Ref(Mutability::Mut)) => return,
- Some(CaptureKind::Ref(Mutability::Not)) if binding_ref_mutability == Mutability::Mut => {
- return;
- },
- Some(CaptureKind::Ref(Mutability::Not)) | None => (),
- }
- }
- }
- },
- None => return,
- };
-
- let mut app = Applicability::MachineApplicable;
-
- // 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()
- };
-
- let body_str = if let PatKind::Binding(annotation, id, some_binding, None) = some_pat.kind {
- if_chain! {
- if !some_expr.needs_unsafe_block;
- if let Some(func) = can_pass_as_func(cx, id, some_expr.expr);
- if func.span.ctxt() == some_expr.expr.span.ctxt();
- then {
- snippet_with_applicability(cx, func.span, "..", &mut app).into_owned()
+ span_lint_and_sugg(
+ cx,
+ MANUAL_MAP,
+ expr.span,
+ "manual implementation of `Option::map`",
+ "try this",
+ if sugg_info.needs_brackets {
+ format!(
+ "{{ {}{}.map({}) }}",
+ sugg_info.scrutinee_str, sugg_info.as_ref_str, sugg_info.body_str
+ )
} else {
- if path_to_local_id(some_expr.expr, id)
- && !is_lint_allowed(cx, MATCH_AS_REF, expr.hir_id)
- && binding_ref.is_some()
- {
- return;
- }
-
- // `ref` and `ref mut` annotations were handled earlier.
- let annotation = if matches!(annotation, BindingAnnotation::MUT) {
- "mut "
- } else {
- ""
- };
- let expr_snip = snippet_with_context(cx, some_expr.expr.span, expr_ctxt, "..", &mut app).0;
- if some_expr.needs_unsafe_block {
- format!("|{}{}| unsafe {{ {} }}", annotation, some_binding, expr_snip)
- } else {
- format!("|{}{}| {}", annotation, some_binding, expr_snip)
- }
- }
- }
- } else if !is_wild_none && explicit_ref.is_none() {
- // TODO: handle explicit reference annotations.
- let pat_snip = snippet_with_context(cx, some_pat.span, expr_ctxt, "..", &mut app).0;
- let expr_snip = snippet_with_context(cx, some_expr.expr.span, expr_ctxt, "..", &mut app).0;
- if some_expr.needs_unsafe_block {
- format!("|{}| unsafe {{ {} }}", pat_snip, expr_snip)
- } else {
- format!("|{}| {}", pat_snip, expr_snip)
- }
- } 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 else_pat.is_none() && 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.
-// Returns the function to be passed to `map` if it exists.
-fn can_pass_as_func<'tcx>(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()
- && !type_is_unsafe_function(cx, cx.typeck_results().expr_ty(func).peel_refs()) =>
- {
- Some(func)
- },
- _ => None,
- }
-}
-
-enum OptionPat<'a> {
- Wild,
- None,
- Some {
- // The pattern contained in the `Some` tuple.
- pattern: &'a Pat<'a>,
- // The number of references before the `Some` tuple.
- // e.g. `&&Some(_)` has a ref count of 2.
- ref_count: usize,
- },
-}
-
-struct SomeExpr<'tcx> {
- expr: &'tcx Expr<'tcx>,
- needs_unsafe_block: bool,
-}
-
-// Try to parse into a recognized `Option` pattern.
-// i.e. `_`, `None`, `Some(..)`, or a reference to any of those.
-fn try_parse_pattern<'tcx>(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, ctxt: SyntaxContext) -> Option<OptionPat<'tcx>> {
- fn f<'tcx>(
- cx: &LateContext<'tcx>,
- pat: &'tcx Pat<'_>,
- 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::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 =>
- {
- Some(OptionPat::Some { pattern, ref_count })
+ format!(
+ "{}{}.map({})",
+ sugg_info.scrutinee_str, sugg_info.as_ref_str, sugg_info.body_str
+ )
},
- _ => None,
- }
+ sugg_info.app,
+ );
}
- f(cx, pat, 0, ctxt)
}
// Checks for an expression wrapped by the `Some` constructor. Returns the contained expression.
fn get_some_expr<'tcx>(
cx: &LateContext<'tcx>,
+ _: &'tcx Pat<'_>,
expr: &'tcx Expr<'_>,
- needs_unsafe_block: bool,
ctxt: SyntaxContext,
) -> Option<SomeExpr<'tcx>> {
- // TODO: Allow more complex expressions.
- match expr.kind {
- ExprKind::Call(
- Expr {
- kind: ExprKind::Path(ref qpath),
- ..
- },
- [arg],
- ) if ctxt == expr.span.ctxt() && is_lang_ctor(cx, qpath, OptionSome) => Some(SomeExpr {
- expr: arg,
- needs_unsafe_block,
- }),
- ExprKind::Block(
- Block {
- stmts: [],
- expr: Some(expr),
- rules,
- ..
+ fn get_some_expr_internal<'tcx>(
+ cx: &LateContext<'tcx>,
+ expr: &'tcx Expr<'_>,
+ needs_unsafe_block: bool,
+ ctxt: SyntaxContext,
+ ) -> Option<SomeExpr<'tcx>> {
+ // TODO: Allow more complex expressions.
+ match expr.kind {
+ ExprKind::Call(callee, [arg])
+ if ctxt == expr.span.ctxt() && is_res_lang_ctor(cx, path_res(cx, callee), OptionSome) =>
+ {
+ Some(SomeExpr::new_no_negated(arg, needs_unsafe_block))
},
- _,
- ) => get_some_expr(
- cx,
- expr,
- needs_unsafe_block || *rules == BlockCheckMode::UnsafeBlock(UnsafeSource::UserProvided),
- ctxt,
- ),
- _ => None,
+ ExprKind::Block(
+ Block {
+ stmts: [],
+ expr: Some(expr),
+ rules,
+ ..
+ },
+ _,
+ ) => get_some_expr_internal(
+ cx,
+ expr,
+ needs_unsafe_block || *rules == BlockCheckMode::UnsafeBlock(UnsafeSource::UserProvided),
+ ctxt,
+ ),
+ _ => None,
+ }
}
-}
-
-// Checks for the `None` value.
-fn is_none_expr(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
- matches!(peel_blocks(expr).kind, ExprKind::Path(ref qpath) if is_lang_ctor(cx, qpath, OptionNone))
+ get_some_expr_internal(cx, expr, false, ctxt)
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-26 21:26:16 +0000