Merge pull request #2803 from Nemo157/trivially_copy_pass_by_ref

New Lint: Pass small trivially copyable objects by value
This commit is contained in:
Philipp Krones 2018-06-15 17:44:44 +02:00 committed by GitHub
commit 3d3d3732c0
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GPG Key ID: 4AEE18F83AFDEB23
35 changed files with 431 additions and 102 deletions

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@ -71,14 +71,14 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
fn check_lit(cx: &LateContext, lit: &Lit, e: &Expr) {
match lit.node {
LitKind::Float(ref s, FloatTy::F32) => check_known_consts(cx, e, s, "f32"),
LitKind::Float(ref s, FloatTy::F64) => check_known_consts(cx, e, s, "f64"),
LitKind::FloatUnsuffixed(ref s) => check_known_consts(cx, e, s, "f{32, 64}"),
LitKind::Float(s, FloatTy::F32) => check_known_consts(cx, e, s, "f32"),
LitKind::Float(s, FloatTy::F64) => check_known_consts(cx, e, s, "f64"),
LitKind::FloatUnsuffixed(s) => check_known_consts(cx, e, s, "f{32, 64}"),
_ => (),
}
}
fn check_known_consts(cx: &LateContext, e: &Expr, s: &symbol::Symbol, module: &str) {
fn check_known_consts(cx: &LateContext, e: &Expr, s: symbol::Symbol, module: &str) {
let s = s.as_str();
if s.parse::<f64>().is_ok() {
for &(constant, name, min_digits) in KNOWN_CONSTS {

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@ -151,7 +151,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AttrPass {
fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item) {
if is_relevant_item(cx.tcx, item) {
check_attrs(cx, item.span, &item.name, &item.attrs)
check_attrs(cx, item.span, item.name, &item.attrs)
}
match item.node {
ItemExternCrate(_) | ItemUse(_, _) => {
@ -195,13 +195,13 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AttrPass {
fn check_impl_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx ImplItem) {
if is_relevant_impl(cx.tcx, item) {
check_attrs(cx, item.span, &item.name, &item.attrs)
check_attrs(cx, item.span, item.name, &item.attrs)
}
}
fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx TraitItem) {
if is_relevant_trait(cx.tcx, item) {
check_attrs(cx, item.span, &item.name, &item.attrs)
check_attrs(cx, item.span, item.name, &item.attrs)
}
}
}
@ -260,7 +260,7 @@ fn is_relevant_expr(tcx: TyCtxt, tables: &ty::TypeckTables, expr: &Expr) -> bool
}
}
fn check_attrs(cx: &LateContext, span: Span, name: &Name, attrs: &[Attribute]) {
fn check_attrs(cx: &LateContext, span: Span, name: Name, attrs: &[Attribute]) {
if in_macro(span) {
return;
}

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@ -112,9 +112,9 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BitMask {
if let ExprBinary(ref cmp, ref left, ref right) = e.node {
if cmp.node.is_comparison() {
if let Some(cmp_opt) = fetch_int_literal(cx, right) {
check_compare(cx, left, cmp.node, cmp_opt, &e.span)
check_compare(cx, left, cmp.node, cmp_opt, e.span)
} else if let Some(cmp_val) = fetch_int_literal(cx, left) {
check_compare(cx, right, invert_cmp(cmp.node), cmp_val, &e.span)
check_compare(cx, right, invert_cmp(cmp.node), cmp_val, e.span)
}
}
}
@ -156,7 +156,7 @@ fn invert_cmp(cmp: BinOp_) -> BinOp_ {
}
fn check_compare(cx: &LateContext, bit_op: &Expr, cmp_op: BinOp_, cmp_value: u128, span: &Span) {
fn check_compare(cx: &LateContext, bit_op: &Expr, cmp_op: BinOp_, cmp_value: u128, span: Span) {
if let ExprBinary(ref op, ref left, ref right) = bit_op.node {
if op.node != BiBitAnd && op.node != BiBitOr {
return;
@ -167,7 +167,7 @@ fn check_compare(cx: &LateContext, bit_op: &Expr, cmp_op: BinOp_, cmp_value: u12
}
}
fn check_bit_mask(cx: &LateContext, bit_op: BinOp_, cmp_op: BinOp_, mask_value: u128, cmp_value: u128, span: &Span) {
fn check_bit_mask(cx: &LateContext, bit_op: BinOp_, cmp_op: BinOp_, mask_value: u128, cmp_value: u128, span: Span) {
match cmp_op {
BiEq | BiNe => match bit_op {
BiBitAnd => if mask_value & cmp_value != cmp_value {
@ -175,7 +175,7 @@ fn check_bit_mask(cx: &LateContext, bit_op: BinOp_, cmp_op: BinOp_, mask_value:
span_lint(
cx,
BAD_BIT_MASK,
*span,
span,
&format!(
"incompatible bit mask: `_ & {}` can never be equal to `{}`",
mask_value,
@ -184,13 +184,13 @@ fn check_bit_mask(cx: &LateContext, bit_op: BinOp_, cmp_op: BinOp_, mask_value:
);
}
} else if mask_value == 0 {
span_lint(cx, BAD_BIT_MASK, *span, "&-masking with zero");
span_lint(cx, BAD_BIT_MASK, span, "&-masking with zero");
},
BiBitOr => if mask_value | cmp_value != cmp_value {
span_lint(
cx,
BAD_BIT_MASK,
*span,
span,
&format!(
"incompatible bit mask: `_ | {}` can never be equal to `{}`",
mask_value,
@ -205,7 +205,7 @@ fn check_bit_mask(cx: &LateContext, bit_op: BinOp_, cmp_op: BinOp_, mask_value:
span_lint(
cx,
BAD_BIT_MASK,
*span,
span,
&format!(
"incompatible bit mask: `_ & {}` will always be lower than `{}`",
mask_value,
@ -213,13 +213,13 @@ fn check_bit_mask(cx: &LateContext, bit_op: BinOp_, cmp_op: BinOp_, mask_value:
),
);
} else if mask_value == 0 {
span_lint(cx, BAD_BIT_MASK, *span, "&-masking with zero");
span_lint(cx, BAD_BIT_MASK, span, "&-masking with zero");
},
BiBitOr => if mask_value >= cmp_value {
span_lint(
cx,
BAD_BIT_MASK,
*span,
span,
&format!(
"incompatible bit mask: `_ | {}` will never be lower than `{}`",
mask_value,
@ -227,9 +227,9 @@ fn check_bit_mask(cx: &LateContext, bit_op: BinOp_, cmp_op: BinOp_, mask_value:
),
);
} else {
check_ineffective_lt(cx, *span, mask_value, cmp_value, "|");
check_ineffective_lt(cx, span, mask_value, cmp_value, "|");
},
BiBitXor => check_ineffective_lt(cx, *span, mask_value, cmp_value, "^"),
BiBitXor => check_ineffective_lt(cx, span, mask_value, cmp_value, "^"),
_ => (),
},
BiLe | BiGt => match bit_op {
@ -237,7 +237,7 @@ fn check_bit_mask(cx: &LateContext, bit_op: BinOp_, cmp_op: BinOp_, mask_value:
span_lint(
cx,
BAD_BIT_MASK,
*span,
span,
&format!(
"incompatible bit mask: `_ & {}` will never be higher than `{}`",
mask_value,
@ -245,13 +245,13 @@ fn check_bit_mask(cx: &LateContext, bit_op: BinOp_, cmp_op: BinOp_, mask_value:
),
);
} else if mask_value == 0 {
span_lint(cx, BAD_BIT_MASK, *span, "&-masking with zero");
span_lint(cx, BAD_BIT_MASK, span, "&-masking with zero");
},
BiBitOr => if mask_value > cmp_value {
span_lint(
cx,
BAD_BIT_MASK,
*span,
span,
&format!(
"incompatible bit mask: `_ | {}` will always be higher than `{}`",
mask_value,
@ -259,9 +259,9 @@ fn check_bit_mask(cx: &LateContext, bit_op: BinOp_, cmp_op: BinOp_, mask_value:
),
);
} else {
check_ineffective_gt(cx, *span, mask_value, cmp_value, "|");
check_ineffective_gt(cx, span, mask_value, cmp_value, "|");
},
BiBitXor => check_ineffective_gt(cx, *span, mask_value, cmp_value, "^"),
BiBitXor => check_ineffective_gt(cx, span, mask_value, cmp_value, "^"),
_ => (),
},
_ => (),

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@ -52,7 +52,7 @@ impl LintPass for EqOp {
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for EqOp {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
if let ExprBinary(ref op, ref left, ref right) = e.node {
if let ExprBinary(op, ref left, ref right) = e.node {
if in_macro(e.span) {
return;
}
@ -157,7 +157,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for EqOp {
}
fn is_valid_operator(op: &BinOp) -> bool {
fn is_valid_operator(op: BinOp) -> bool {
match op.node {
BiSub | BiDiv | BiEq | BiLt | BiLe | BiGt | BiGe | BiNe | BiAnd | BiOr | BiBitXor | BiBitAnd | BiBitOr => true,
_ => false,

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@ -46,9 +46,9 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ExcessivePrecision {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
if_chain! {
let ty = cx.tables.expr_ty(expr);
if let TypeVariants::TyFloat(ref fty) = ty.sty;
if let TypeVariants::TyFloat(fty) = ty.sty;
if let hir::ExprLit(ref lit) = expr.node;
if let LitKind::Float(ref sym, _) | LitKind::FloatUnsuffixed(ref sym) = lit.node;
if let LitKind::Float(sym, _) | LitKind::FloatUnsuffixed(sym) = lit.node;
if let Some(sugg) = self.check(sym, fty);
then {
span_lint_and_sugg(
@ -66,7 +66,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ExcessivePrecision {
impl ExcessivePrecision {
// None if nothing to lint, Some(suggestion) if lint neccessary
fn check(&self, sym: &Symbol, fty: &FloatTy) -> Option<String> {
fn check(&self, sym: Symbol, fty: FloatTy) -> Option<String> {
let max = max_digits(fty);
let sym_str = sym.as_str();
if dot_zero_exclusion(&sym_str) {
@ -79,7 +79,7 @@ impl ExcessivePrecision {
let digits = count_digits(&sym_str);
if digits > max as usize {
let formatter = FloatFormat::new(&sym_str);
let sr = match *fty {
let sr = match fty {
FloatTy::F32 => sym_str.parse::<f32>().map(|f| formatter.format(f)),
FloatTy::F64 => sym_str.parse::<f64>().map(|f| formatter.format(f)),
};
@ -115,7 +115,7 @@ fn dot_zero_exclusion(s: &str) -> bool {
}
}
fn max_digits(fty: &FloatTy) -> u32 {
fn max_digits(fty: FloatTy) -> u32 {
match fty {
FloatTy::F32 => f32::DIGITS,
FloatTy::F64 => f64::DIGITS,

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@ -126,7 +126,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Functions {
}
impl<'a, 'tcx> Functions {
fn check_arg_number(&self, cx: &LateContext, decl: &hir::FnDecl, span: Span) {
fn check_arg_number(self, cx: &LateContext, decl: &hir::FnDecl, span: Span) {
let args = decl.inputs.len() as u64;
if args > self.threshold {
span_lint(
@ -139,7 +139,7 @@ impl<'a, 'tcx> Functions {
}
fn check_raw_ptr(
&self,
self,
cx: &LateContext<'a, 'tcx>,
unsafety: hir::Unsafety,
decl: &'tcx hir::FnDecl,

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@ -38,12 +38,12 @@ impl LintPass for Pass {
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
fn check_trait_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx TraitItem) {
if let TraitItemKind::Method(_, TraitMethod::Required(_)) = item.node {
check_attrs(cx, &item.name, &item.attrs);
check_attrs(cx, item.name, &item.attrs);
}
}
}
fn check_attrs(cx: &LateContext, name: &Name, attrs: &[Attribute]) {
fn check_attrs(cx: &LateContext, name: Name, attrs: &[Attribute]) {
for attr in attrs {
if attr.name() != "inline" {
continue;

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@ -196,6 +196,7 @@ pub mod suspicious_trait_impl;
pub mod swap;
pub mod temporary_assignment;
pub mod transmute;
pub mod trivially_copy_pass_by_ref;
pub mod types;
pub mod unicode;
pub mod unsafe_removed_from_name;
@ -399,6 +400,10 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
reg.register_late_lint_pass(box large_enum_variant::LargeEnumVariant::new(conf.enum_variant_size_threshold));
reg.register_late_lint_pass(box explicit_write::Pass);
reg.register_late_lint_pass(box needless_pass_by_value::NeedlessPassByValue);
reg.register_late_lint_pass(box trivially_copy_pass_by_ref::TriviallyCopyPassByRef::new(
conf.trivial_copy_size_limit,
&reg.sess.target,
));
reg.register_early_lint_pass(box literal_representation::LiteralDigitGrouping);
reg.register_early_lint_pass(box literal_representation::LiteralRepresentation::new(
conf.literal_representation_threshold
@ -672,6 +677,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
transmute::TRANSMUTE_PTR_TO_REF,
transmute::USELESS_TRANSMUTE,
transmute::WRONG_TRANSMUTE,
trivially_copy_pass_by_ref::TRIVIALLY_COPY_PASS_BY_REF,
types::ABSURD_EXTREME_COMPARISONS,
types::BORROWED_BOX,
types::BOX_VEC,
@ -916,6 +922,7 @@ pub fn register_plugins(reg: &mut rustc_plugin::Registry) {
methods::SINGLE_CHAR_PATTERN,
misc::CMP_OWNED,
mutex_atomic::MUTEX_ATOMIC,
trivially_copy_pass_by_ref::TRIVIALLY_COPY_PASS_BY_REF,
types::BOX_VEC,
vec::USELESS_VEC,
]);

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@ -227,12 +227,12 @@ enum WarningType {
}
impl WarningType {
pub fn display(&self, grouping_hint: &str, cx: &EarlyContext, span: &syntax_pos::Span) {
match *self {
pub fn display(&self, grouping_hint: &str, cx: &EarlyContext, span: syntax_pos::Span) {
match self {
WarningType::UnreadableLiteral => span_lint_and_sugg(
cx,
UNREADABLE_LITERAL,
*span,
span,
"long literal lacking separators",
"consider",
grouping_hint.to_owned(),
@ -240,7 +240,7 @@ impl WarningType {
WarningType::LargeDigitGroups => span_lint_and_sugg(
cx,
LARGE_DIGIT_GROUPS,
*span,
span,
"digit groups should be smaller",
"consider",
grouping_hint.to_owned(),
@ -248,7 +248,7 @@ impl WarningType {
WarningType::InconsistentDigitGrouping => span_lint_and_sugg(
cx,
INCONSISTENT_DIGIT_GROUPING,
*span,
span,
"digits grouped inconsistently by underscores",
"consider",
grouping_hint.to_owned(),
@ -256,7 +256,7 @@ impl WarningType {
WarningType::DecimalRepresentation => span_lint_and_sugg(
cx,
DECIMAL_LITERAL_REPRESENTATION,
*span,
span,
"integer literal has a better hexadecimal representation",
"consider",
grouping_hint.to_owned(),
@ -291,7 +291,7 @@ impl EarlyLintPass for LiteralDigitGrouping {
}
impl LiteralDigitGrouping {
fn check_lit(&self, cx: &EarlyContext, lit: &Lit) {
fn check_lit(self, cx: &EarlyContext, lit: &Lit) {
match lit.node {
LitKind::Int(..) => {
// Lint integral literals.
@ -302,7 +302,7 @@ impl LiteralDigitGrouping {
then {
let digit_info = DigitInfo::new(&src, false);
let _ = Self::do_lint(digit_info.digits).map_err(|warning_type| {
warning_type.display(&digit_info.grouping_hint(), cx, &lit.span)
warning_type.display(&digit_info.grouping_hint(), cx, lit.span)
});
}
}
@ -337,15 +337,15 @@ impl LiteralDigitGrouping {
if !consistent {
WarningType::InconsistentDigitGrouping.display(&digit_info.grouping_hint(),
cx,
&lit.span);
lit.span);
}
})
.map_err(|warning_type| warning_type.display(&digit_info.grouping_hint(),
cx,
&lit.span));
lit.span));
}
})
.map_err(|warning_type| warning_type.display(&digit_info.grouping_hint(), cx, &lit.span));
.map_err(|warning_type| warning_type.display(&digit_info.grouping_hint(), cx, lit.span));
}
}
},
@ -436,7 +436,7 @@ impl LiteralRepresentation {
threshold,
}
}
fn check_lit(&self, cx: &EarlyContext, lit: &Lit) {
fn check_lit(self, cx: &EarlyContext, lit: &Lit) {
// Lint integral literals.
if_chain! {
if let LitKind::Int(..) = lit.node;
@ -457,7 +457,7 @@ impl LiteralRepresentation {
let hex = format!("{:#X}", val);
let digit_info = DigitInfo::new(&hex[..], false);
let _ = Self::do_lint(digit_info.digits).map_err(|warning_type| {
warning_type.display(&digit_info.grouping_hint(), cx, &lit.span)
warning_type.display(&digit_info.grouping_hint(), cx, lit.span)
});
}
}

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@ -412,7 +412,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
// check for never_loop
match expr.node {
ExprWhile(_, ref block, _) | ExprLoop(ref block, _, _) => {
match never_loop_block(block, &expr.id) {
match never_loop_block(block, expr.id) {
NeverLoopResult::AlwaysBreak =>
span_lint(cx, NEVER_LOOP, expr.span, "this loop never actually loops"),
NeverLoopResult::MayContinueMainLoop | NeverLoopResult::Otherwise => (),
@ -575,7 +575,7 @@ fn combine_branches(b1: NeverLoopResult, b2: NeverLoopResult) -> NeverLoopResult
}
}
fn never_loop_block(block: &Block, main_loop_id: &NodeId) -> NeverLoopResult {
fn never_loop_block(block: &Block, main_loop_id: NodeId) -> NeverLoopResult {
let stmts = block.stmts.iter().map(stmt_to_expr);
let expr = once(block.expr.as_ref().map(|p| &**p));
let mut iter = stmts.chain(expr).filter_map(|e| e);
@ -596,7 +596,7 @@ fn decl_to_expr(decl: &Decl) -> Option<&Expr> {
}
}
fn never_loop_expr(expr: &Expr, main_loop_id: &NodeId) -> NeverLoopResult {
fn never_loop_expr(expr: &Expr, main_loop_id: NodeId) -> NeverLoopResult {
match expr.node {
ExprBox(ref e) |
ExprUnary(_, ref e) |
@ -643,7 +643,7 @@ fn never_loop_expr(expr: &Expr, main_loop_id: &NodeId) -> NeverLoopResult {
ExprAgain(d) => {
let id = d.target_id
.expect("target id can only be missing in the presence of compilation errors");
if id == *main_loop_id {
if id == main_loop_id {
NeverLoopResult::MayContinueMainLoop
} else {
NeverLoopResult::AlwaysBreak
@ -668,17 +668,17 @@ fn never_loop_expr(expr: &Expr, main_loop_id: &NodeId) -> NeverLoopResult {
}
}
fn never_loop_expr_seq<'a, T: Iterator<Item=&'a Expr>>(es: &mut T, main_loop_id: &NodeId) -> NeverLoopResult {
fn never_loop_expr_seq<'a, T: Iterator<Item=&'a Expr>>(es: &mut T, main_loop_id: NodeId) -> NeverLoopResult {
es.map(|e| never_loop_expr(e, main_loop_id))
.fold(NeverLoopResult::Otherwise, combine_seq)
}
fn never_loop_expr_all<'a, T: Iterator<Item=&'a Expr>>(es: &mut T, main_loop_id: &NodeId) -> NeverLoopResult {
fn never_loop_expr_all<'a, T: Iterator<Item=&'a Expr>>(es: &mut T, main_loop_id: NodeId) -> NeverLoopResult {
es.map(|e| never_loop_expr(e, main_loop_id))
.fold(NeverLoopResult::Otherwise, combine_both)
}
fn never_loop_expr_branch<'a, T: Iterator<Item=&'a Expr>>(e: &mut T, main_loop_id: &NodeId) -> NeverLoopResult {
fn never_loop_expr_branch<'a, T: Iterator<Item=&'a Expr>>(e: &mut T, main_loop_id: NodeId) -> NeverLoopResult {
e.map(|e| never_loop_expr(e, main_loop_id))
.fold(NeverLoopResult::AlwaysBreak, combine_branches)
}
@ -1032,7 +1032,7 @@ fn check_for_loop_range<'a, 'tcx>(
};
let take = if let Some(end) = *end {
if is_len_call(end, &indexed) {
if is_len_call(end, indexed) {
"".to_owned()
} else {
match limits {
@ -1096,14 +1096,14 @@ fn check_for_loop_range<'a, 'tcx>(
}
}
fn is_len_call(expr: &Expr, var: &Name) -> bool {
fn is_len_call(expr: &Expr, var: Name) -> bool {
if_chain! {
if let ExprMethodCall(ref method, _, ref len_args) = expr.node;
if len_args.len() == 1;
if method.name == "len";
if let ExprPath(QPath::Resolved(_, ref path)) = len_args[0].node;
if path.segments.len() == 1;
if path.segments[0].name == *var;
if path.segments[0].name == var;
then {
return true;
}

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@ -2079,8 +2079,8 @@ impl SelfKind {
}
}
fn description(&self) -> &'static str {
match *self {
fn description(self) -> &'static str {
match self {
SelfKind::Value => "self by value",
SelfKind::Ref => "self by reference",
SelfKind::RefMut => "self by mutable reference",
@ -2164,13 +2164,13 @@ enum OutType {
}
impl OutType {
fn matches(&self, ty: &hir::FunctionRetTy) -> bool {
fn matches(self, ty: &hir::FunctionRetTy) -> bool {
match (self, ty) {
(&OutType::Unit, &hir::DefaultReturn(_)) => true,
(&OutType::Unit, &hir::Return(ref ty)) if ty.node == hir::TyTup(vec![].into()) => true,
(&OutType::Bool, &hir::Return(ref ty)) if is_bool(ty) => true,
(&OutType::Any, &hir::Return(ref ty)) if ty.node != hir::TyTup(vec![].into()) => true,
(&OutType::Ref, &hir::Return(ref ty)) => matches!(ty.node, hir::TyRptr(_, _)),
(OutType::Unit, &hir::DefaultReturn(_)) => true,
(OutType::Unit, &hir::Return(ref ty)) if ty.node == hir::TyTup(vec![].into()) => true,
(OutType::Bool, &hir::Return(ref ty)) if is_bool(ty) => true,
(OutType::Any, &hir::Return(ref ty)) if ty.node != hir::TyTup(vec![].into()) => true,
(OutType::Ref, &hir::Return(ref ty)) => matches!(ty.node, hir::TyRptr(_, _)),
_ => false,
}
}

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@ -349,7 +349,7 @@ impl EarlyLintPass for MiscEarly {
}
impl MiscEarly {
fn check_lit(&self, cx: &EarlyContext, lit: &Lit) {
fn check_lit(self, cx: &EarlyContext, lit: &Lit) {
if_chain! {
if let LitKind::Int(value, ..) = lit.node;
if let Some(src) = snippet_opt(cx, lit.span);

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@ -92,7 +92,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for SuspiciousImpl {
if let Some(impl_trait) = check_binop(
cx,
expr,
&binop.node,
binop.node,
&["Add", "Sub", "Mul", "Div"],
&[BiAdd, BiSub, BiMul, BiDiv],
) {
@ -110,7 +110,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for SuspiciousImpl {
if let Some(impl_trait) = check_binop(
cx,
expr,
&binop.node,
binop.node,
&[
"AddAssign",
"SubAssign",
@ -144,7 +144,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for SuspiciousImpl {
fn check_binop<'a>(
cx: &LateContext,
expr: &hir::Expr,
binop: &hir::BinOp_,
binop: hir::BinOp_,
traits: &[&'a str],
expected_ops: &[hir::BinOp_],
) -> Option<&'a str> {
@ -169,7 +169,7 @@ fn check_binop<'a>(
if let hir::map::Node::NodeItem(item) = cx.tcx.hir.get(parent_impl);
if let hir::Item_::ItemImpl(_, _, _, _, Some(ref trait_ref), _, _) = item.node;
if let Some(idx) = trait_ids.iter().position(|&tid| tid == trait_ref.path.def.def_id());
if *binop != expected_ops[idx];
if binop != expected_ops[idx];
then{
return Some(traits[idx])
}

View File

@ -0,0 +1,144 @@
use std::cmp;
use rustc::hir::*;
use rustc::hir::map::*;
use rustc::hir::intravisit::FnKind;
use rustc::lint::*;
use rustc::ty::TypeVariants;
use rustc::session::config::Config as SessionConfig;
use rustc_target::spec::abi::Abi;
use rustc_target::abi::LayoutOf;
use syntax::ast::NodeId;
use syntax_pos::Span;
use crate::utils::{in_macro, is_copy, is_self, span_lint_and_sugg, snippet};
/// **What it does:** Checks for functions taking arguments by reference, where
/// the argument type is `Copy` and small enough to be more efficient to always
/// pass by value.
///
/// **Why is this bad?** In many calling conventions instances of structs will
/// be passed through registers if they fit into two or less general purpose
/// registers.
///
/// **Known problems:** This lint is target register size dependent, it is
/// limited to 32-bit to try and reduce portability problems between 32 and
/// 64-bit, but if you are compiling for 8 or 16-bit targets then the limit
/// will be different.
///
/// The configuration option `trivial_copy_size_limit` can be set to override
/// this limit for a project.
///
/// **Example:**
/// ```rust
/// fn foo(v: &u32) {
/// assert_eq!(v, 42);
/// }
/// // should be
/// fn foo(v: u32) {
/// assert_eq!(v, 42);
/// }
/// ```
declare_clippy_lint! {
pub TRIVIALLY_COPY_PASS_BY_REF,
perf,
"functions taking small copyable arguments by reference"
}
pub struct TriviallyCopyPassByRef {
limit: u64,
}
impl TriviallyCopyPassByRef {
pub fn new(limit: Option<u64>, target: &SessionConfig) -> Self {
let limit = limit.unwrap_or_else(|| {
let bit_width = target.usize_ty.bit_width().expect("usize should have a width") as u64;
// Cap the calculated bit width at 32-bits to reduce
// portability problems between 32 and 64-bit targets
let bit_width = cmp::min(bit_width, 32);
let byte_width = bit_width / 8;
// Use a limit of 2 times the register bit width
byte_width * 2
});
Self { limit }
}
}
impl LintPass for TriviallyCopyPassByRef {
fn get_lints(&self) -> LintArray {
lint_array![TRIVIALLY_COPY_PASS_BY_REF]
}
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for TriviallyCopyPassByRef {
fn check_fn(
&mut self,
cx: &LateContext<'a, 'tcx>,
kind: FnKind<'tcx>,
decl: &'tcx FnDecl,
body: &'tcx Body,
span: Span,
node_id: NodeId,
) {
if in_macro(span) {
return;
}
match kind {
FnKind::ItemFn(.., abi, _, attrs) => {
if abi != Abi::Rust {
return;
}
for a in attrs {
if a.meta_item_list().is_some() && a.name() == "proc_macro_derive" {
return;
}
}
},
FnKind::Method(..) => (),
_ => return,
}
// Exclude non-inherent impls
if let Some(NodeItem(item)) = cx.tcx.hir.find(cx.tcx.hir.get_parent_node(node_id)) {
if matches!(item.node, ItemImpl(_, _, _, _, Some(_), _, _) |
ItemTrait(..))
{
return;
}
}
let fn_def_id = cx.tcx.hir.local_def_id(node_id);
let fn_sig = cx.tcx.fn_sig(fn_def_id);
let fn_sig = cx.tcx.erase_late_bound_regions(&fn_sig);
for ((input, &ty), arg) in decl.inputs.iter().zip(fn_sig.inputs()).zip(&body.arguments) {
// All spans generated from a proc-macro invocation are the same...
if span == input.span {
return;
}
if_chain! {
if let TypeVariants::TyRef(_, ty, Mutability::MutImmutable) = ty.sty;
if is_copy(cx, ty);
if let Some(size) = cx.layout_of(ty).ok().map(|l| l.size.bytes());
if size <= self.limit;
if let Ty_::TyRptr(_, MutTy { ty: ref decl_ty, .. }) = input.node;
then {
let value_type = if is_self(arg) {
"self".into()
} else {
snippet(cx, decl_ty.span, "_").into()
};
span_lint_and_sugg(
cx,
TRIVIALLY_COPY_PASS_BY_REF,
input.span,
"this argument is passed by reference, but would be more efficient if passed by value",
"consider passing by value instead",
value_type);
}
}
}
}
}

View File

@ -1606,12 +1606,12 @@ fn node_as_const_fullint<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr)
}
}
fn err_upcast_comparison(cx: &LateContext, span: &Span, expr: &Expr, always: bool) {
fn err_upcast_comparison(cx: &LateContext, span: Span, expr: &Expr, always: bool) {
if let ExprCast(ref cast_val, _) = expr.node {
span_lint(
cx,
INVALID_UPCAST_COMPARISONS,
*span,
span,
&format!(
"because of the numeric bounds on `{}` prior to casting, this expression is always {}",
snippet(cx, cast_val.span, "the expression"),
@ -1623,7 +1623,7 @@ fn err_upcast_comparison(cx: &LateContext, span: &Span, expr: &Expr, always: boo
fn upcast_comparison_bounds_err<'a, 'tcx>(
cx: &LateContext<'a, 'tcx>,
span: &Span,
span: Span,
rel: comparisons::Rel,
lhs_bounds: Option<(FullInt, FullInt)>,
lhs: &'tcx Expr,
@ -1684,8 +1684,8 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for InvalidUpcastComparisons {
let lhs_bounds = numeric_cast_precast_bounds(cx, normalized_lhs);
let rhs_bounds = numeric_cast_precast_bounds(cx, normalized_rhs);
upcast_comparison_bounds_err(cx, &expr.span, rel, lhs_bounds, normalized_lhs, normalized_rhs, false);
upcast_comparison_bounds_err(cx, &expr.span, rel, rhs_bounds, normalized_rhs, normalized_lhs, true);
upcast_comparison_bounds_err(cx, expr.span, rel, lhs_bounds, normalized_lhs, normalized_rhs, false);
upcast_comparison_bounds_err(cx, expr.span, rel, rhs_bounds, normalized_rhs, normalized_lhs, true);
}
}
}

View File

@ -36,12 +36,12 @@ impl LintPass for UnsafeNameRemoval {
impl EarlyLintPass for UnsafeNameRemoval {
fn check_item(&mut self, cx: &EarlyContext, item: &Item) {
if let ItemKind::Use(ref use_tree) = item.node {
check_use_tree(use_tree, cx, &item.span);
check_use_tree(use_tree, cx, item.span);
}
}
}
fn check_use_tree(use_tree: &UseTree, cx: &EarlyContext, span: &Span) {
fn check_use_tree(use_tree: &UseTree, cx: &EarlyContext, span: Span) {
match use_tree.kind {
UseTreeKind::Simple(Some(new_name)) => {
let old_name = use_tree
@ -62,14 +62,14 @@ fn check_use_tree(use_tree: &UseTree, cx: &EarlyContext, span: &Span) {
}
}
fn unsafe_to_safe_check(old_name: Ident, new_name: Ident, cx: &EarlyContext, span: &Span) {
fn unsafe_to_safe_check(old_name: Ident, new_name: Ident, cx: &EarlyContext, span: Span) {
let old_str = old_name.name.as_str();
let new_str = new_name.name.as_str();
if contains_unsafe(&old_str) && !contains_unsafe(&new_str) {
span_lint(
cx,
UNSAFE_REMOVED_FROM_NAME,
*span,
span,
&format!("removed \"unsafe\" from the name of `{}` in use as `{}`", old_str, new_str),
);
}

View File

@ -156,6 +156,8 @@ define_Conf! {
(verbose_bit_mask_threshold, "verbose_bit_mask_threshold", 1 => u64),
/// Lint: DECIMAL_LITERAL_REPRESENTATION. The lower bound for linting decimal literals
(literal_representation_threshold, "literal_representation_threshold", 16384 => u64),
/// Lint: TRIVIALLY_COPY_PASS_BY_REF. The maximum size (in bytes) to consider a `Copy` type for passing by value instead of by reference.
(trivial_copy_size_limit, "trivial_copy_size_limit", None => Option<u64>),
}
/// Search for the configuration file.

View File

@ -349,7 +349,7 @@ impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
let c: fn(_) -> _ = ExprAgain;
c.hash(&mut self.s);
if let Some(i) = i.label {
self.hash_name(&i.name);
self.hash_name(i.name);
}
},
ExprYield(ref e) => {
@ -386,7 +386,7 @@ impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
let c: fn(_, _) -> _ = ExprBreak;
c.hash(&mut self.s);
if let Some(i) = i.label {
self.hash_name(&i.name);
self.hash_name(i.name);
}
if let Some(ref j) = *j {
self.hash_expr(&*j);
@ -419,7 +419,7 @@ impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
let c: fn(_, _) -> _ = ExprField;
c.hash(&mut self.s);
self.hash_expr(e);
self.hash_name(&f.name);
self.hash_name(f.name);
},
ExprIndex(ref a, ref i) => {
let c: fn(_, _) -> _ = ExprIndex;
@ -450,7 +450,7 @@ impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
c.hash(&mut self.s);
self.hash_block(b);
if let Some(i) = *i {
self.hash_name(&i.name);
self.hash_name(i.name);
}
},
ExprMatch(ref e, ref arms, ref s) => {
@ -471,7 +471,7 @@ impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
ExprMethodCall(ref path, ref _tys, ref args) => {
let c: fn(_, _, _) -> _ = ExprMethodCall;
c.hash(&mut self.s);
self.hash_name(&path.name);
self.hash_name(path.name);
self.hash_exprs(args);
},
ExprRepeat(ref e, ref l_id) => {
@ -502,7 +502,7 @@ impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
self.hash_qpath(path);
for f in fields {
self.hash_name(&f.ident.name);
self.hash_name(f.ident.name);
self.hash_expr(&f.expr);
}
@ -541,7 +541,7 @@ impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
self.hash_expr(cond);
self.hash_block(b);
if let Some(l) = l {
self.hash_name(&l.name);
self.hash_name(l.name);
}
},
}
@ -553,7 +553,7 @@ impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
}
}
pub fn hash_name(&mut self, n: &Name) {
pub fn hash_name(&mut self, n: Name) {
n.as_str().hash(&mut self.s);
}
@ -563,7 +563,7 @@ impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
self.hash_path(path);
},
QPath::TypeRelative(_, ref path) => {
self.hash_name(&path.name);
self.hash_name(path.name);
},
}
// self.cx.tables.qpath_def(p, id).hash(&mut self.s);
@ -572,7 +572,7 @@ impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
pub fn hash_path(&mut self, p: &Path) {
p.is_global().hash(&mut self.s);
for p in &p.segments {
self.hash_name(&p.name);
self.hash_name(p.name);
}
}

View File

@ -0,0 +1 @@
trivial-copy-size-limit = 2

View File

@ -0,0 +1,19 @@
#![allow(many_single_char_names)]
#[derive(Copy, Clone)]
struct Foo(u8);
#[derive(Copy, Clone)]
struct Bar(u32);
fn good(a: &mut u32, b: u32, c: &Bar, d: &u32) {
}
fn bad(x: &u16, y: &Foo) {
}
fn main() {
let (mut a, b, c, d, x, y) = (0, 0, Bar(0), 0, 0, Foo(0));
good(&mut a, b, &c, &d);
bad(&x, &y);
}

View File

@ -0,0 +1,16 @@
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/test.rs:12:11
|
12 | fn bad(x: &u16, y: &Foo) {
| ^^^^ help: consider passing by value instead: `u16`
|
= note: `-D trivially-copy-pass-by-ref` implied by `-D warnings`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/test.rs:12:20
|
12 | fn bad(x: &u16, y: &Foo) {
| ^^^^ help: consider passing by value instead: `Foo`
error: aborting due to 2 previous errors

View File

@ -1,4 +1,4 @@
error: error reading Clippy's configuration file `$DIR/clippy.toml`: unknown field `foobar`, expected one of `blacklisted-names`, `cyclomatic-complexity-threshold`, `doc-valid-idents`, `too-many-arguments-threshold`, `type-complexity-threshold`, `single-char-binding-names-threshold`, `too-large-for-stack`, `enum-variant-name-threshold`, `enum-variant-size-threshold`, `verbose-bit-mask-threshold`, `literal-representation-threshold`, `third-party`
error: error reading Clippy's configuration file `$DIR/clippy.toml`: unknown field `foobar`, expected one of `blacklisted-names`, `cyclomatic-complexity-threshold`, `doc-valid-idents`, `too-many-arguments-threshold`, `type-complexity-threshold`, `single-char-binding-names-threshold`, `too-large-for-stack`, `enum-variant-name-threshold`, `enum-variant-size-threshold`, `verbose-bit-mask-threshold`, `literal-representation-threshold`, `trivial-copy-size-limit`, `third-party`
error: aborting due to previous error

View File

@ -5,6 +5,7 @@ pub fn dec_read_dec(i: &mut i32) -> i32 {
ret
}
#[allow(trivially_copy_pass_by_ref)]
pub fn minus_1(i: &i32) -> i32 {
dec_read_dec(&mut i.clone())
}

View File

@ -1,6 +1,6 @@
#![allow(unknown_lints, unused, no_effect, redundant_closure_call, many_single_char_names, needless_pass_by_value, option_map_unit_fn)]
#![allow(unknown_lints, unused, no_effect, redundant_closure_call, many_single_char_names, needless_pass_by_value, option_map_unit_fn, trivially_copy_pass_by_ref)]
#![warn(redundant_closure, needless_borrow)]
fn main() {

View File

@ -1,7 +1,7 @@
#![feature(iterator_for_each)]
use std::iter::repeat;
#[allow(trivially_copy_pass_by_ref)]
fn square_is_lower_64(x: &u32) -> bool { x * x < 64 }
#[allow(maybe_infinite_iter)]

View File

@ -1,4 +1,4 @@
#![allow(trivially_copy_pass_by_ref)]
fn fn_val(i: i32) -> i32 { unimplemented!() }

View File

@ -2,7 +2,7 @@
#![warn(needless_lifetimes, extra_unused_lifetimes)]
#![allow(dead_code, needless_pass_by_value)]
#![allow(dead_code, needless_pass_by_value, trivially_copy_pass_by_ref)]
fn distinct_lifetimes<'a, 'b>(_x: &'a u8, _y: &'b u8, _z: u8) { }

View File

@ -1,6 +1,6 @@
#![allow(unused)]
#![allow(unused, trivially_copy_pass_by_ref)]
#![warn(mut_from_ref)]
struct Foo;

View File

@ -1,7 +1,7 @@
#![allow(unused_variables)]
#![allow(unused_variables, trivially_copy_pass_by_ref)]
fn takes_an_immutable_reference(a: &i32) {}
fn takes_a_mutable_reference(a: &mut i32) {}

View File

@ -1,6 +1,6 @@
use std::borrow::Cow;
#[allow(trivially_copy_pass_by_ref)]
fn x(y: &i32) -> i32 {
*y
}

View File

@ -0,0 +1,57 @@
#![allow(many_single_char_names, blacklisted_name)]
#[derive(Copy, Clone)]
struct Foo(u32);
#[derive(Copy, Clone)]
struct Bar([u8; 24]);
type Baz = u32;
fn good(a: &mut u32, b: u32, c: &Bar) {
}
fn bad(x: &u32, y: &Foo, z: &Baz) {
}
impl Foo {
fn good(self, a: &mut u32, b: u32, c: &Bar) {
}
fn good2(&mut self) {
}
fn bad(&self, x: &u32, y: &Foo, z: &Baz) {
}
fn bad2(x: &u32, y: &Foo, z: &Baz) {
}
}
impl AsRef<u32> for Foo {
fn as_ref(&self) -> &u32 {
&self.0
}
}
impl Bar {
fn good(&self, a: &mut u32, b: u32, c: &Bar) {
}
fn bad2(x: &u32, y: &Foo, z: &Baz) {
}
}
fn main() {
let (mut foo, bar) = (Foo(0), Bar([0; 24]));
let (mut a, b, c, x, y, z) = (0, 0, Bar([0; 24]), 0, Foo(0), 0);
good(&mut a, b, &c);
bad(&x, &y, &z);
foo.good(&mut a, b, &c);
foo.good2();
foo.bad(&x, &y, &z);
Foo::bad2(&x, &y, &z);
bar.good(&mut a, b, &c);
Bar::bad2(&x, &y, &z);
foo.as_ref();
}

View File

@ -0,0 +1,82 @@
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:14:11
|
14 | fn bad(x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `u32`
|
= note: `-D trivially-copy-pass-by-ref` implied by `-D warnings`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:14:20
|
14 | fn bad(x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `Foo`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:14:29
|
14 | fn bad(x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `Baz`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:24:12
|
24 | fn bad(&self, x: &u32, y: &Foo, z: &Baz) {
| ^^^^^ help: consider passing by value instead: `self`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:24:22
|
24 | fn bad(&self, x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `u32`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:24:31
|
24 | fn bad(&self, x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `Foo`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:24:40
|
24 | fn bad(&self, x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `Baz`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:27:16
|
27 | fn bad2(x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `u32`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:27:25
|
27 | fn bad2(x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `Foo`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:27:34
|
27 | fn bad2(x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `Baz`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:41:16
|
41 | fn bad2(x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `u32`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:41:25
|
41 | fn bad2(x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `Foo`
error: this argument is passed by reference, but would be more efficient if passed by value
--> $DIR/trivially_copy_pass_by_ref.rs:41:34
|
41 | fn bad2(x: &u32, y: &Foo, z: &Baz) {
| ^^^^ help: consider passing by value instead: `Baz`
error: aborting due to 13 previous errors

View File

@ -1,6 +1,6 @@
#![allow(unused, dead_code, needless_lifetimes, needless_pass_by_value)]
#![allow(unused, dead_code, needless_lifetimes, needless_pass_by_value, trivially_copy_pass_by_ref)]
#![warn(extra_unused_lifetimes)]
fn empty() {

View File

@ -1,5 +1,5 @@
#![deny(useless_asref)]
#![allow(trivially_copy_pass_by_ref)]
use std::fmt::Debug;
struct FakeAsRef;

View File

@ -3,7 +3,7 @@
#![warn(wrong_self_convention)]
#![warn(wrong_pub_self_convention)]
#![allow(dead_code)]
#![allow(dead_code, trivially_copy_pass_by_ref)]
fn main() {}