-use crate::consts::{constant, Constant};
+use crate::consts::constant;
use crate::reexport::Name;
use crate::utils::paths;
use crate::utils::usage::{is_unused, mutated_variables};
multispan_sugg, snippet, snippet_opt, snippet_with_applicability, span_lint, span_lint_and_help,
span_lint_and_sugg, span_lint_and_then, SpanlessEq,
};
-use crate::utils::{is_type_diagnostic_item, qpath_res, same_tys, sext, sugg};
+use crate::utils::{is_type_diagnostic_item, qpath_res, same_tys, sugg};
use if_chain::if_chain;
-use itertools::Itertools;
use rustc_ast::ast;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_errors::Applicability;
use rustc_hir::def::{DefKind, Res};
use rustc_hir::intravisit::{walk_block, walk_expr, walk_pat, walk_stmt, NestedVisitorMap, Visitor};
use rustc_hir::{
- def_id, BinOpKind, BindingAnnotation, Block, BorrowKind, Expr, ExprKind, GenericArg, HirId, LoopSource,
- MatchSource, Mutability, Node, Pat, PatKind, QPath, Stmt, StmtKind,
+ def_id, BinOpKind, BindingAnnotation, Block, BorrowKind, Expr, ExprKind, GenericArg, HirId, InlineAsmOperand,
+ LoopSource, MatchSource, Mutability, Node, Pat, PatKind, QPath, Stmt, StmtKind,
};
use rustc_infer::infer::TyCtxtInferExt;
use rustc_lint::{LateContext, LateLintPass, LintContext};
}
declare_clippy_lint! {
- /// **What it does:** Checks for `for` loops over `Option` values.
+ /// **What it does:** Checks for `for` loops over `Option` or `Result` values.
///
/// **Why is this bad?** Readability. This is more clearly expressed as an `if
/// let`.
/// **Known problems:** None.
///
/// **Example:**
- /// ```ignore
- /// for x in option {
- /// ..
+ /// ```rust
+ /// # let opt = Some(1);
+ ///
+ /// // Bad
+ /// for x in opt {
+ /// // ..
/// }
- /// ```
///
- /// This should be
- /// ```ignore
- /// if let Some(x) = option {
- /// ..
+ /// // Good
+ /// if let Some(x) = opt {
+ /// // ..
/// }
/// ```
- pub FOR_LOOP_OVER_OPTION,
- correctness,
- "for-looping over an `Option`, which is more clearly expressed as an `if let`"
-}
-
-declare_clippy_lint! {
- /// **What it does:** Checks for `for` loops over `Result` values.
///
- /// **Why is this bad?** Readability. This is more clearly expressed as an `if
- /// let`.
+ /// // or
///
- /// **Known problems:** None.
+ /// ```rust
+ /// # let res: Result<i32, std::io::Error> = Ok(1);
///
- /// **Example:**
- /// ```ignore
- /// for x in result {
- /// ..
+ /// // Bad
+ /// for x in &res {
+ /// // ..
/// }
- /// ```
///
- /// This should be
- /// ```ignore
- /// if let Ok(x) = result {
- /// ..
+ /// // Good
+ /// if let Ok(x) = res {
+ /// // ..
/// }
/// ```
- pub FOR_LOOP_OVER_RESULT,
+ pub FOR_LOOPS_OVER_FALLIBLES,
correctness,
- "for-looping over a `Result`, which is more clearly expressed as an `if let`"
+ "for-looping over an `Option` or a `Result`, which is more clearly expressed as an `if let`"
}
declare_clippy_lint! {
"collecting an iterator when collect is not needed"
}
-declare_clippy_lint! {
- /// **What it does:** Checks for loops over ranges `x..y` where both `x` and `y`
- /// are constant and `x` is greater or equal to `y`, unless the range is
- /// reversed or has a negative `.step_by(_)`.
- ///
- /// **Why is it bad?** Such loops will either be skipped or loop until
- /// wrap-around (in debug code, this may `panic!()`). Both options are probably
- /// not intended.
- ///
- /// **Known problems:** The lint cannot catch loops over dynamically defined
- /// ranges. Doing this would require simulating all possible inputs and code
- /// paths through the program, which would be complex and error-prone.
- ///
- /// **Example:**
- /// ```ignore
- /// for x in 5..10 - 5 {
- /// ..
- /// } // oops, stray `-`
- /// ```
- pub REVERSE_RANGE_LOOP,
- correctness,
- "iteration over an empty range, such as `10..0` or `5..5`"
-}
-
declare_clippy_lint! {
/// **What it does:** Checks `for` loops over slices with an explicit counter
/// and suggests the use of `.enumerate()`.
EXPLICIT_ITER_LOOP,
EXPLICIT_INTO_ITER_LOOP,
ITER_NEXT_LOOP,
- FOR_LOOP_OVER_RESULT,
- FOR_LOOP_OVER_OPTION,
+ FOR_LOOPS_OVER_FALLIBLES,
WHILE_LET_LOOP,
NEEDLESS_COLLECT,
- REVERSE_RANGE_LOOP,
EXPLICIT_COUNTER_LOOP,
EMPTY_LOOP,
WHILE_LET_ON_ITERATOR,
NeverLoopResult::AlwaysBreak
}
},
+ ExprKind::InlineAsm(ref asm) => asm
+ .operands
+ .iter()
+ .map(|o| match o {
+ InlineAsmOperand::In { expr, .. }
+ | InlineAsmOperand::InOut { expr, .. }
+ | InlineAsmOperand::Const { expr }
+ | InlineAsmOperand::Sym { expr } => never_loop_expr(expr, main_loop_id),
+ InlineAsmOperand::Out { expr, .. } => never_loop_expr_all(&mut expr.iter(), main_loop_id),
+ InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => {
+ never_loop_expr_all(&mut once(in_expr).chain(out_expr.iter()), main_loop_id)
+ },
+ })
+ .fold(NeverLoopResult::Otherwise, combine_both),
ExprKind::Struct(_, _, None)
| ExprKind::Yield(_, _)
| ExprKind::Closure(_, _, _, _, _)
expr: &'tcx Expr<'_>,
) {
check_for_loop_range(cx, pat, arg, body, expr);
- check_for_loop_reverse_range(cx, arg, expr);
check_for_loop_arg(cx, pat, arg, expr);
check_for_loop_explicit_counter(cx, pat, arg, body, expr);
check_for_loop_over_map_kv(cx, pat, arg, body, expr);
fn same_var<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &Expr<'_>, var: HirId) -> bool {
if_chain! {
- if let ExprKind::Path(ref qpath) = expr.kind;
- if let QPath::Resolved(None, ref path) = *qpath;
+ if let ExprKind::Path(qpath) = &expr.kind;
+ if let QPath::Resolved(None, path) = qpath;
if path.segments.len() == 1;
if let Res::Local(local_id) = qpath_res(cx, qpath, expr.hir_id);
- // our variable!
- if local_id == var;
then {
- return true;
+ // our variable!
+ local_id == var
+ } else {
+ false
}
}
+}
- false
+#[derive(Clone, Copy)]
+enum OffsetSign {
+ Positive,
+ Negative,
}
struct Offset {
value: String,
- negate: bool,
+ sign: OffsetSign,
}
impl Offset {
- fn negative(s: String) -> Self {
- Self { value: s, negate: true }
+ fn negative(value: String) -> Self {
+ Self {
+ value,
+ sign: OffsetSign::Negative,
+ }
}
- fn positive(s: String) -> Self {
+ fn positive(value: String) -> Self {
Self {
- value: s,
- negate: false,
+ value,
+ sign: OffsetSign::Positive,
}
}
}
-struct FixedOffsetVar {
- var_name: String,
+struct FixedOffsetVar<'hir> {
+ var: &'hir Expr<'hir>,
offset: Offset,
}
is_slice || is_type_diagnostic_item(cx, ty, sym!(vec_type)) || is_type_diagnostic_item(cx, ty, sym!(vecdeque_type))
}
-fn get_fixed_offset_var<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &Expr<'_>, var: HirId) -> Option<FixedOffsetVar> {
+fn fetch_cloned_expr<'tcx>(expr: &'tcx Expr<'tcx>) -> &'tcx Expr<'tcx> {
+ if_chain! {
+ if let ExprKind::MethodCall(method, _, args) = expr.kind;
+ if method.ident.name == sym!(clone);
+ if args.len() == 1;
+ if let Some(arg) = args.get(0);
+ then { arg } else { expr }
+ }
+}
+
+fn get_offset<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, idx: &Expr<'_>, var: HirId) -> Option<Offset> {
fn extract_offset<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, e: &Expr<'_>, var: HirId) -> Option<String> {
- match e.kind {
- ExprKind::Lit(ref l) => match l.node {
+ match &e.kind {
+ ExprKind::Lit(l) => match l.node {
ast::LitKind::Int(x, _ty) => Some(x.to_string()),
_ => None,
},
}
}
- if let ExprKind::Index(ref seqexpr, ref idx) = expr.kind {
- let ty = cx.tables.expr_ty(seqexpr);
- if !is_slice_like(cx, ty) {
- return None;
- }
-
- let offset = match idx.kind {
- ExprKind::Binary(op, ref lhs, ref rhs) => match op.node {
- BinOpKind::Add => {
- let offset_opt = if same_var(cx, lhs, var) {
- extract_offset(cx, rhs, var)
- } else if same_var(cx, rhs, var) {
- extract_offset(cx, lhs, var)
- } else {
- None
- };
-
- offset_opt.map(Offset::positive)
- },
- BinOpKind::Sub if same_var(cx, lhs, var) => extract_offset(cx, rhs, var).map(Offset::negative),
- _ => None,
- },
- ExprKind::Path(..) => {
- if same_var(cx, idx, var) {
- Some(Offset::positive("0".into()))
+ match idx.kind {
+ ExprKind::Binary(op, lhs, rhs) => match op.node {
+ BinOpKind::Add => {
+ let offset_opt = if same_var(cx, lhs, var) {
+ extract_offset(cx, rhs, var)
+ } else if same_var(cx, rhs, var) {
+ extract_offset(cx, lhs, var)
} else {
None
- }
+ };
+
+ offset_opt.map(Offset::positive)
},
+ BinOpKind::Sub if same_var(cx, lhs, var) => extract_offset(cx, rhs, var).map(Offset::negative),
_ => None,
- };
-
- offset.map(|o| FixedOffsetVar {
- var_name: snippet_opt(cx, seqexpr.span).unwrap_or_else(|| "???".into()),
- offset: o,
- })
- } else {
- None
- }
-}
-
-fn fetch_cloned_fixed_offset_var<'a, 'tcx>(
- cx: &LateContext<'a, 'tcx>,
- expr: &Expr<'_>,
- var: HirId,
-) -> Option<FixedOffsetVar> {
- if_chain! {
- if let ExprKind::MethodCall(ref method, _, ref args) = expr.kind;
- if method.ident.name == sym!(clone);
- if args.len() == 1;
- if let Some(arg) = args.get(0);
- then {
- return get_fixed_offset_var(cx, arg, var);
- }
+ },
+ ExprKind::Path(..) if same_var(cx, idx, var) => Some(Offset::positive("0".into())),
+ _ => None,
}
-
- get_fixed_offset_var(cx, expr, var)
}
-fn get_indexed_assignments<'a, 'tcx>(
- cx: &LateContext<'a, 'tcx>,
- body: &Expr<'_>,
- var: HirId,
-) -> Vec<(FixedOffsetVar, FixedOffsetVar)> {
- fn get_assignment<'a, 'tcx>(
- cx: &LateContext<'a, 'tcx>,
- e: &Expr<'_>,
- var: HirId,
- ) -> Option<(FixedOffsetVar, FixedOffsetVar)> {
- if let ExprKind::Assign(ref lhs, ref rhs, _) = e.kind {
- match (
- get_fixed_offset_var(cx, lhs, var),
- fetch_cloned_fixed_offset_var(cx, rhs, var),
- ) {
- (Some(offset_left), Some(offset_right)) => {
- // Source and destination must be different
- if offset_left.var_name == offset_right.var_name {
- None
- } else {
- Some((offset_left, offset_right))
- }
- },
- _ => None,
- }
+fn get_assignments<'tcx>(body: &'tcx Expr<'tcx>) -> impl Iterator<Item = Option<(&'tcx Expr<'tcx>, &'tcx Expr<'tcx>)>> {
+ fn get_assignment<'tcx>(e: &'tcx Expr<'tcx>) -> Option<(&'tcx Expr<'tcx>, &'tcx Expr<'tcx>)> {
+ if let ExprKind::Assign(lhs, rhs, _) = e.kind {
+ Some((lhs, rhs))
} else {
None
}
}
- if let ExprKind::Block(ref b, _) = body.kind {
- let Block {
- ref stmts, ref expr, ..
- } = **b;
+ // This is one of few ways to return different iterators
+ // derived from: https://stackoverflow.com/questions/29760668/conditionally-iterate-over-one-of-several-possible-iterators/52064434#52064434
+ let mut iter_a = None;
+ let mut iter_b = None;
- stmts
+ if let ExprKind::Block(b, _) = body.kind {
+ let Block { stmts, expr, .. } = *b;
+
+ iter_a = stmts
.iter()
- .map(|stmt| match stmt.kind {
+ .filter_map(|stmt| match stmt.kind {
StmtKind::Local(..) | StmtKind::Item(..) => None,
- StmtKind::Expr(ref e) | StmtKind::Semi(ref e) => Some(get_assignment(cx, e, var)),
+ StmtKind::Expr(e) | StmtKind::Semi(e) => Some(e),
})
- .chain(expr.as_ref().into_iter().map(|e| Some(get_assignment(cx, &*e, var))))
- .filter_map(|op| op)
- .collect::<Option<Vec<_>>>()
- .unwrap_or_default()
+ .chain(expr.into_iter())
+ .map(get_assignment)
+ .into()
} else {
- get_assignment(cx, body, var).into_iter().collect()
+ iter_b = Some(get_assignment(body))
}
+
+ iter_a.into_iter().flatten().chain(iter_b.into_iter())
}
+fn build_manual_memcpy_suggestion<'a, 'tcx>(
+ cx: &LateContext<'a, 'tcx>,
+ start: &Expr<'_>,
+ end: &Expr<'_>,
+ limits: ast::RangeLimits,
+ dst_var: FixedOffsetVar<'_>,
+ src_var: FixedOffsetVar<'_>,
+) -> String {
+ fn print_sum(arg1: &str, arg2: &Offset) -> String {
+ match (arg1, &arg2.value[..], arg2.sign) {
+ ("0", "0", _) => "0".into(),
+ ("0", x, OffsetSign::Positive) | (x, "0", _) => x.into(),
+ ("0", x, OffsetSign::Negative) => format!("-{}", x),
+ (x, y, OffsetSign::Positive) => format!("({} + {})", x, y),
+ (x, y, OffsetSign::Negative) => {
+ if x == y {
+ "0".into()
+ } else {
+ format!("({} - {})", x, y)
+ }
+ },
+ }
+ }
+
+ fn print_offset(start_str: &str, inline_offset: &Offset) -> String {
+ let offset = print_sum(start_str, inline_offset);
+ if offset.as_str() == "0" {
+ "".into()
+ } else {
+ offset
+ }
+ }
+
+ let print_limit = |end: &Expr<'_>, offset: Offset, var: &Expr<'_>| {
+ if_chain! {
+ if let ExprKind::MethodCall(method, _, len_args) = end.kind;
+ if method.ident.name == sym!(len);
+ if len_args.len() == 1;
+ if let Some(arg) = len_args.get(0);
+ if var_def_id(cx, arg) == var_def_id(cx, var);
+ then {
+ match offset.sign {
+ OffsetSign::Negative => format!("({} - {})", snippet(cx, end.span, "<src>.len()"), offset.value),
+ OffsetSign::Positive => "".into(),
+ }
+ } else {
+ let end_str = match limits {
+ ast::RangeLimits::Closed => {
+ let end = sugg::Sugg::hir(cx, end, "<count>");
+ format!("{}", end + sugg::ONE)
+ },
+ ast::RangeLimits::HalfOpen => format!("{}", snippet(cx, end.span, "..")),
+ };
+
+ print_sum(&end_str, &offset)
+ }
+ }
+ };
+
+ let start_str = snippet(cx, start.span, "").to_string();
+ let dst_offset = print_offset(&start_str, &dst_var.offset);
+ let dst_limit = print_limit(end, dst_var.offset, dst_var.var);
+ let src_offset = print_offset(&start_str, &src_var.offset);
+ let src_limit = print_limit(end, src_var.offset, src_var.var);
+
+ let dst_var_name = snippet_opt(cx, dst_var.var.span).unwrap_or_else(|| "???".into());
+ let src_var_name = snippet_opt(cx, src_var.var.span).unwrap_or_else(|| "???".into());
+
+ let dst = if dst_offset == "" && dst_limit == "" {
+ dst_var_name
+ } else {
+ format!("{}[{}..{}]", dst_var_name, dst_offset, dst_limit)
+ };
+
+ format!(
+ "{}.clone_from_slice(&{}[{}..{}])",
+ dst, src_var_name, src_offset, src_limit
+ )
+}
/// Checks for for loops that sequentially copy items from one slice-like
/// object to another.
fn detect_manual_memcpy<'a, 'tcx>(
) {
if let Some(higher::Range {
start: Some(start),
- ref end,
+ end: Some(end),
limits,
}) = higher::range(cx, arg)
{
// the var must be a single name
if let PatKind::Binding(_, canonical_id, _, _) = pat.kind {
- let print_sum = |arg1: &Offset, arg2: &Offset| -> String {
- match (&arg1.value[..], arg1.negate, &arg2.value[..], arg2.negate) {
- ("0", _, "0", _) => "".into(),
- ("0", _, x, false) | (x, false, "0", false) => x.into(),
- ("0", _, x, true) | (x, false, "0", true) => format!("-{}", x),
- (x, false, y, false) => format!("({} + {})", x, y),
- (x, false, y, true) => {
- if x == y {
- "0".into()
- } else {
- format!("({} - {})", x, y)
- }
- },
- (x, true, y, false) => {
- if x == y {
- "0".into()
- } else {
- format!("({} - {})", y, x)
- }
- },
- (x, true, y, true) => format!("-({} + {})", x, y),
- }
- };
-
- let print_limit = |end: &Option<&Expr<'_>>, offset: Offset, var_name: &str| {
- if let Some(end) = *end {
- if_chain! {
- if let ExprKind::MethodCall(ref method, _, ref len_args) = end.kind;
- if method.ident.name == sym!(len);
- if len_args.len() == 1;
- if let Some(arg) = len_args.get(0);
- if snippet(cx, arg.span, "??") == var_name;
- then {
- return if offset.negate {
- format!("({} - {})", snippet(cx, end.span, "<src>.len()"), offset.value)
- } else {
- String::new()
- };
- }
- }
-
- let end_str = match limits {
- ast::RangeLimits::Closed => {
- let end = sugg::Sugg::hir(cx, end, "<count>");
- format!("{}", end + sugg::ONE)
- },
- ast::RangeLimits::HalfOpen => format!("{}", snippet(cx, end.span, "..")),
- };
-
- print_sum(&Offset::positive(end_str), &offset)
- } else {
- "..".into()
- }
- };
-
// The only statements in the for loops can be indexed assignments from
// indexed retrievals.
- let manual_copies = get_indexed_assignments(cx, body, canonical_id);
-
- let big_sugg = manual_copies
- .into_iter()
- .map(|(dst_var, src_var)| {
- let start_str = Offset::positive(snippet(cx, start.span, "").to_string());
- let dst_offset = print_sum(&start_str, &dst_var.offset);
- let dst_limit = print_limit(end, dst_var.offset, &dst_var.var_name);
- let src_offset = print_sum(&start_str, &src_var.offset);
- let src_limit = print_limit(end, src_var.offset, &src_var.var_name);
- let dst = if dst_offset == "" && dst_limit == "" {
- dst_var.var_name
- } else {
- format!("{}[{}..{}]", dst_var.var_name, dst_offset, dst_limit)
- };
-
- format!(
- "{}.clone_from_slice(&{}[{}..{}])",
- dst, src_var.var_name, src_offset, src_limit
- )
+ let big_sugg = get_assignments(body)
+ .map(|o| {
+ o.and_then(|(lhs, rhs)| {
+ let rhs = fetch_cloned_expr(rhs);
+ if_chain! {
+ if let ExprKind::Index(seqexpr_left, idx_left) = lhs.kind;
+ if let ExprKind::Index(seqexpr_right, idx_right) = rhs.kind;
+ if is_slice_like(cx, cx.tables.expr_ty(seqexpr_left))
+ && is_slice_like(cx, cx.tables.expr_ty(seqexpr_right));
+ if let Some(offset_left) = get_offset(cx, &idx_left, canonical_id);
+ if let Some(offset_right) = get_offset(cx, &idx_right, canonical_id);
+
+ // Source and destination must be different
+ if var_def_id(cx, seqexpr_left) != var_def_id(cx, seqexpr_right);
+ then {
+ Some((FixedOffsetVar { var: seqexpr_left, offset: offset_left },
+ FixedOffsetVar { var: seqexpr_right, offset: offset_right }))
+ } else {
+ None
+ }
+ }
+ })
})
- .join("\n ");
+ .map(|o| o.map(|(dst, src)| build_manual_memcpy_suggestion(cx, start, end, limits, dst, src)))
+ .collect::<Option<Vec<_>>>()
+ .filter(|v| !v.is_empty())
+ .map(|v| v.join("\n "));
- if !big_sugg.is_empty() {
+ if let Some(big_sugg) = big_sugg {
span_lint_and_sugg(
cx,
MANUAL_MEMCPY,
|diag| {
multispan_sugg(
diag,
- "consider using an iterator".to_string(),
+ "consider using an iterator",
vec![
(pat.span, format!("({}, <item>)", ident.name)),
(
|diag| {
multispan_sugg(
diag,
- "consider using an iterator".to_string(),
+ "consider using an iterator",
vec![(pat.span, "<item>".to_string()), (arg.span, repl)],
);
},
false
}
-fn check_for_loop_reverse_range<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, arg: &'tcx Expr<'_>, expr: &'tcx Expr<'_>) {
- // if this for loop is iterating over a two-sided range...
- if let Some(higher::Range {
- start: Some(start),
- end: Some(end),
- limits,
- }) = higher::range(cx, arg)
- {
- // ...and both sides are compile-time constant integers...
- if let Some((start_idx, _)) = constant(cx, cx.tables, start) {
- if let Some((end_idx, _)) = constant(cx, cx.tables, end) {
- // ...and the start index is greater than the end index,
- // this loop will never run. This is often confusing for developers
- // who think that this will iterate from the larger value to the
- // smaller value.
- let ty = cx.tables.expr_ty(start);
- let (sup, eq) = match (start_idx, end_idx) {
- (Constant::Int(start_idx), Constant::Int(end_idx)) => (
- match ty.kind {
- ty::Int(ity) => sext(cx.tcx, start_idx, ity) > sext(cx.tcx, end_idx, ity),
- ty::Uint(_) => start_idx > end_idx,
- _ => false,
- },
- start_idx == end_idx,
- ),
- _ => (false, false),
- };
-
- if sup {
- let start_snippet = snippet(cx, start.span, "_");
- let end_snippet = snippet(cx, end.span, "_");
- let dots = if limits == ast::RangeLimits::Closed {
- "..="
- } else {
- ".."
- };
-
- span_lint_and_then(
- cx,
- REVERSE_RANGE_LOOP,
- expr.span,
- "this range is empty so this for loop will never run",
- |diag| {
- diag.span_suggestion(
- arg.span,
- "consider using the following if you are attempting to iterate over this \
- range in reverse",
- format!(
- "({end}{dots}{start}).rev()",
- end = end_snippet,
- dots = dots,
- start = start_snippet
- ),
- Applicability::MaybeIncorrect,
- );
- },
- );
- } else if eq && limits != ast::RangeLimits::Closed {
- // if they are equal, it's also problematic - this loop
- // will never run.
- span_lint(
- cx,
- REVERSE_RANGE_LOOP,
- expr.span,
- "this range is empty so this for loop will never run",
- );
- }
- }
- }
- }
-}
-
fn lint_iter_method(cx: &LateContext<'_, '_>, args: &[Expr<'_>], arg: &Expr<'_>, method_name: &str) {
let mut applicability = Applicability::MachineApplicable;
let object = snippet_with_applicability(cx, args[0].span, "_", &mut applicability);
ITER_NEXT_LOOP,
expr.span,
"you are iterating over `Iterator::next()` which is an Option; this will compile but is \
- probably not what you want",
+ probably not what you want",
);
next_loop_linted = true;
}
if is_type_diagnostic_item(cx, ty, sym!(option_type)) {
span_lint_and_help(
cx,
- FOR_LOOP_OVER_OPTION,
+ FOR_LOOPS_OVER_FALLIBLES,
arg.span,
&format!(
"for loop over `{0}`, which is an `Option`. This is more readably written as an \
- `if let` statement.",
+ `if let` statement.",
snippet(cx, arg.span, "_")
),
None,
} else if is_type_diagnostic_item(cx, ty, sym!(result_type)) {
span_lint_and_help(
cx,
- FOR_LOOP_OVER_RESULT,
+ FOR_LOOPS_OVER_FALLIBLES,
arg.span,
&format!(
"for loop over `{0}`, which is a `Result`. This is more readably written as an \
- `if let` statement.",
+ `if let` statement.",
snippet(cx, arg.span, "_")
),
None,
let map = sugg::Sugg::hir(cx, arg, "map");
multispan_sugg(
diag,
- "use the corresponding method".into(),
+ "use the corresponding method",
vec
projects / rust.git / blobdiff