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Merge commit '0cb0f7636851f9fcc57085cf80197a2ef6db098f' into clippyup

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This commit is contained in:
Philipp Krones
2022-06-30 10:50:09 +02:00
parent ee37029afa
commit 09f5df5087
243 changed files with 9046 additions and 3487 deletions
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44
clippy_utils/src/hir_utils.rs
View File

@@ -1,4 +1,5 @@
use crate::consts::constant_simple;
use crate::macros::macro_backtrace;
use crate::source::snippet_opt;
use rustc_ast::ast::InlineAsmTemplatePiece;
use rustc_data_structures::fx::FxHasher;
@@ -12,9 +13,13 @@ use rustc_hir::{
use rustc_lexer::{tokenize, TokenKind};
use rustc_lint::LateContext;
use rustc_middle::ty::TypeckResults;
use rustc_span::Symbol;
use rustc_span::{sym, Symbol};
use std::hash::{Hash, Hasher};
/// Callback that is called when two expressions are not equal in the sense of `SpanlessEq`, but
/// other conditions would make them equal.
type SpanlessEqCallback<'a> = dyn FnMut(&Expr<'_>, &Expr<'_>) -> bool + 'a;
/// Type used to check whether two ast are the same. This is different from the
/// operator `==` on ast types as this operator would compare true equality with
/// ID and span.
@@ -25,7 +30,7 @@ pub struct SpanlessEq<'a, 'tcx> {
cx: &'a LateContext<'tcx>,
maybe_typeck_results: Option<(&'tcx TypeckResults<'tcx>, &'tcx TypeckResults<'tcx>)>,
allow_side_effects: bool,
expr_fallback: Option<Box<dyn FnMut(&Expr<'_>, &Expr<'_>) -> bool + 'a>>,
expr_fallback: Option<Box<SpanlessEqCallback<'a>>>,
}
impl<'a, 'tcx> SpanlessEq<'a, 'tcx> {
@@ -121,6 +126,9 @@ impl HirEqInterExpr<'_, '_, '_> {
/// Checks whether two blocks are the same.
fn eq_block(&mut self, left: &Block<'_>, right: &Block<'_>) -> bool {
if self.cannot_be_compared_block(left) || self.cannot_be_compared_block(right) {
return false;
}
match (left.stmts, left.expr, right.stmts, right.expr) {
([], None, [], None) => {
// For empty blocks, check to see if the tokens are equal. This will catch the case where a macro
@@ -171,6 +179,38 @@ impl HirEqInterExpr<'_, '_, '_> {
}
}
fn cannot_be_compared_block(&mut self, block: &Block<'_>) -> bool {
if block.stmts.last().map_or(false, |stmt| {
matches!(
stmt.kind,
StmtKind::Semi(semi_expr) if self.should_ignore(semi_expr)
)
}) {
return true;
}
if let Some(block_expr) = block.expr
&& self.should_ignore(block_expr)
{
return true
}
false
}
fn should_ignore(&mut self, expr: &Expr<'_>) -> bool {
if macro_backtrace(expr.span).last().map_or(false, |macro_call| {
matches!(
&self.inner.cx.tcx.get_diagnostic_name(macro_call.def_id),
Some(sym::todo_macro | sym::unimplemented_macro)
)
}) {
return true;
}
false
}
pub fn eq_array_length(&mut self, left: ArrayLen, right: ArrayLen) -> bool {
match (left, right) {
(ArrayLen::Infer(..), ArrayLen::Infer(..)) => true,

69
clippy_utils/src/lib.rs
View File

@@ -1539,9 +1539,13 @@ pub fn is_try<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'tcx>) -> Option<&'tc
None
}
/// Returns `true` if the lint is allowed in the current context
/// Returns `true` if the lint is allowed in the current context. This is useful for
/// skipping long running code when it's unnecessary
///
/// Useful for skipping long running code when it's unnecessary
/// This function should check the lint level for the same node, that the lint will
/// be emitted at. If the information is buffered to be emitted at a later point, please
/// make sure to use `span_lint_hir` functions to emit the lint. This ensures that
/// expectations at the checked nodes will be fulfilled.
pub fn is_lint_allowed(cx: &LateContext<'_>, lint: &'static Lint, id: HirId) -> bool {
cx.tcx.lint_level_at_node(lint, id).0 == Level::Allow
}
@@ -2058,6 +2062,21 @@ pub fn peel_hir_expr_refs<'a>(expr: &'a Expr<'a>) -> (&'a Expr<'a>, usize) {
(e, count)
}
/// Peels off all references on the type. Returns the underlying type and the number of references
/// removed.
pub fn peel_hir_ty_refs<'a>(mut ty: &'a hir::Ty<'a>) -> (&'a hir::Ty<'a>, usize) {
let mut count = 0;
loop {
match &ty.kind {
TyKind::Rptr(_, ref_ty) => {
ty = ref_ty.ty;
count += 1;
},
_ => break (ty, count),
}
}
}
/// Removes `AddrOf` operators (`&`) or deref operators (`*`), but only if a reference type is
/// dereferenced. An overloaded deref such as `Vec` to slice would not be removed.
pub fn peel_ref_operators<'hir>(cx: &LateContext<'_>, mut expr: &'hir Expr<'hir>) -> &'hir Expr<'hir> {
@@ -2110,7 +2129,7 @@ fn with_test_item_names<'tcx>(tcx: TyCtxt<'tcx>, module: LocalDefId, f: impl Fn(
}
}
names.sort_unstable();
f(&*entry.insert(names))
f(entry.insert(names))
},
}
}
@@ -2168,6 +2187,50 @@ pub fn is_test_module_or_function(tcx: TyCtxt<'_>, item: &Item<'_>) -> bool {
&& item.ident.name.as_str().split('_').any(|a| a == "test" || a == "tests")
}
/// Walks the HIR tree from the given expression, up to the node where the value produced by the
/// expression is consumed. Calls the function for every node encountered this way until it returns
/// `Some`.
///
/// This allows walking through `if`, `match`, `break`, block expressions to find where the value
/// produced by the expression is consumed.
pub fn walk_to_expr_usage<'tcx, T>(
cx: &LateContext<'tcx>,
e: &Expr<'tcx>,
mut f: impl FnMut(Node<'tcx>, HirId) -> Option<T>,
) -> Option<T> {
let map = cx.tcx.hir();
let mut iter = map.parent_iter(e.hir_id);
let mut child_id = e.hir_id;
while let Some((parent_id, parent)) = iter.next() {
if let Some(x) = f(parent, child_id) {
return Some(x);
}
let parent = match parent {
Node::Expr(e) => e,
Node::Block(Block { expr: Some(body), .. }) | Node::Arm(Arm { body, .. }) if body.hir_id == child_id => {
child_id = parent_id;
continue;
},
Node::Arm(a) if a.body.hir_id == child_id => {
child_id = parent_id;
continue;
},
_ => return None,
};
match parent.kind {
ExprKind::If(child, ..) | ExprKind::Match(child, ..) if child.hir_id != child_id => child_id = parent_id,
ExprKind::Break(Destination { target_id: Ok(id), .. }, _) => {
child_id = id;
iter = map.parent_iter(id);
},
ExprKind::Block(..) => child_id = parent_id,
_ => return None,
}
}
None
}
macro_rules! op_utils {
($($name:ident $assign:ident)*) => {
/// Binary operation traits like `LangItem::Add`

9
clippy_utils/src/msrvs.rs
View File

@@ -12,8 +12,8 @@ macro_rules! msrv_aliases {
// names may refer to stabilized feature flags or library items
msrv_aliases! {
1,53,0 { OR_PATTERNS, MANUAL_BITS }
1,52,0 { STR_SPLIT_ONCE }
1,53,0 { OR_PATTERNS, MANUAL_BITS, BTREE_MAP_RETAIN, BTREE_SET_RETAIN }
1,52,0 { STR_SPLIT_ONCE, REM_EUCLID_CONST }
1,51,0 { BORROW_AS_PTR, UNSIGNED_ABS }
1,50,0 { BOOL_THEN }
1,47,0 { TAU }
@@ -23,14 +23,15 @@ msrv_aliases! {
1,42,0 { MATCHES_MACRO, SLICE_PATTERNS, PTR_SLICE_RAW_PARTS }
1,41,0 { RE_REBALANCING_COHERENCE, RESULT_MAP_OR_ELSE }
1,40,0 { MEM_TAKE, NON_EXHAUSTIVE, OPTION_AS_DEREF }
1,38,0 { POINTER_CAST }
1,38,0 { POINTER_CAST, REM_EUCLID }
1,37,0 { TYPE_ALIAS_ENUM_VARIANTS }
1,36,0 { ITERATOR_COPIED }
1,35,0 { OPTION_COPIED, RANGE_CONTAINS }
1,34,0 { TRY_FROM }
1,30,0 { ITERATOR_FIND_MAP, TOOL_ATTRIBUTES }
1,28,0 { FROM_BOOL }
1,26,0 { RANGE_INCLUSIVE }
1,26,0 { RANGE_INCLUSIVE, STRING_RETAIN }
1,18,0 { HASH_MAP_RETAIN, HASH_SET_RETAIN }
1,17,0 { FIELD_INIT_SHORTHAND, STATIC_IN_CONST, EXPECT_ERR }
1,16,0 { STR_REPEAT }
1,24,0 { IS_ASCII_DIGIT }

13
clippy_utils/src/paths.rs
View File

@@ -21,8 +21,14 @@ pub const ASREF_TRAIT: [&str; 3] = ["core", "convert", "AsRef"];
pub const BTREEMAP_CONTAINS_KEY: [&str; 6] = ["alloc", "collections", "btree", "map", "BTreeMap", "contains_key"];
pub const BTREEMAP_ENTRY: [&str; 6] = ["alloc", "collections", "btree", "map", "entry", "Entry"];
pub const BTREEMAP_INSERT: [&str; 6] = ["alloc", "collections", "btree", "map", "BTreeMap", "insert"];
pub const BTREESET_ITER: [&str; 6] = ["alloc", "collections", "btree", "set", "BTreeSet", "iter"];
pub const CLONE_TRAIT_METHOD: [&str; 4] = ["core", "clone", "Clone", "clone"];
pub const COW: [&str; 3] = ["alloc", "borrow", "Cow"];
pub const CORE_ITER_COLLECT: [&str; 6] = ["core", "iter", "traits", "iterator", "Iterator", "collect"];
pub const CORE_ITER_CLONED: [&str; 6] = ["core", "iter", "traits", "iterator", "Iterator", "cloned"];
pub const CORE_ITER_COPIED: [&str; 6] = ["core", "iter", "traits", "iterator", "Iterator", "copied"];
pub const CORE_ITER_FILTER: [&str; 6] = ["core", "iter", "traits", "iterator", "Iterator", "filter"];
pub const CORE_ITER_INTO_ITER: [&str; 6] = ["core", "iter", "traits", "collect", "IntoIterator", "into_iter"];
pub const CSTRING_AS_C_STR: [&str; 5] = ["alloc", "ffi", "c_str", "CString", "as_c_str"];
pub const DEFAULT_TRAIT_METHOD: [&str; 4] = ["core", "default", "Default", "default"];
pub const DEREF_MUT_TRAIT_METHOD: [&str; 5] = ["core", "ops", "deref", "DerefMut", "deref_mut"];
@@ -50,6 +56,7 @@ pub const FUTURES_IO_ASYNCWRITEEXT: [&str; 3] = ["futures_util", "io", "AsyncWri
pub const HASHMAP_CONTAINS_KEY: [&str; 6] = ["std", "collections", "hash", "map", "HashMap", "contains_key"];
pub const HASHMAP_ENTRY: [&str; 5] = ["std", "collections", "hash", "map", "Entry"];
pub const HASHMAP_INSERT: [&str; 6] = ["std", "collections", "hash", "map", "HashMap", "insert"];
pub const HASHSET_ITER: [&str; 6] = ["std", "collections", "hash", "set", "HashSet", "iter"];
#[cfg(feature = "internal")]
pub const IDENT: [&str; 3] = ["rustc_span", "symbol", "Ident"];
#[cfg(feature = "internal")]
@@ -62,6 +69,7 @@ pub const IO_WRITE: [&str; 3] = ["std", "io", "Write"];
pub const IPADDR_V4: [&str; 5] = ["std", "net", "ip", "IpAddr", "V4"];
pub const IPADDR_V6: [&str; 5] = ["std", "net", "ip", "IpAddr", "V6"];
pub const ITER_COUNT: [&str; 6] = ["core", "iter", "traits", "iterator", "Iterator", "count"];
pub const ITER_EMPTY: [&str; 5] = ["core", "iter", "sources", "empty", "Empty"];
pub const ITER_REPEAT: [&str; 5] = ["core", "iter", "sources", "repeat", "repeat"];
#[expect(clippy::invalid_paths)] // internal lints do not know about all external crates
pub const ITERTOOLS_NEXT_TUPLE: [&str; 3] = ["itertools", "Itertools", "next_tuple"];
@@ -83,8 +91,6 @@ pub const OPTION_SOME: [&str; 4] = ["core", "option", "Option", "Some"];
pub const ORD: [&str; 3] = ["core", "cmp", "Ord"];
pub const OS_STRING_AS_OS_STR: [&str; 5] = ["std", "ffi", "os_str", "OsString", "as_os_str"];
pub const OS_STR_TO_OS_STRING: [&str; 5] = ["std", "ffi", "os_str", "OsStr", "to_os_string"];
pub const PARKING_LOT_RAWMUTEX: [&str; 3] = ["parking_lot", "raw_mutex", "RawMutex"];
pub const PARKING_LOT_RAWRWLOCK: [&str; 3] = ["parking_lot", "raw_rwlock", "RawRwLock"];
pub const PARKING_LOT_MUTEX_GUARD: [&str; 3] = ["lock_api", "mutex", "MutexGuard"];
pub const PARKING_LOT_RWLOCK_READ_GUARD: [&str; 3] = ["lock_api", "rwlock", "RwLockReadGuard"];
pub const PARKING_LOT_RWLOCK_WRITE_GUARD: [&str; 3] = ["lock_api", "rwlock", "RwLockWriteGuard"];
@@ -144,6 +150,7 @@ pub const SLICE_FROM_RAW_PARTS: [&str; 4] = ["core", "slice", "raw", "from_raw_p
pub const SLICE_FROM_RAW_PARTS_MUT: [&str; 4] = ["core", "slice", "raw", "from_raw_parts_mut"];
pub const SLICE_GET: [&str; 4] = ["core", "slice", "<impl [T]>", "get"];
pub const SLICE_INTO_VEC: [&str; 4] = ["alloc", "slice", "<impl [T]>", "into_vec"];
pub const SLICE_INTO: [&str; 4] = ["core", "slice", "<impl [T]>", "iter"];
pub const SLICE_ITER: [&str; 4] = ["core", "slice", "iter", "Iter"];
pub const STDERR: [&str; 4] = ["std", "io", "stdio", "stderr"];
pub const STDOUT: [&str; 4] = ["std", "io", "stdio", "stdout"];
@@ -153,6 +160,7 @@ pub const STRING_AS_MUT_STR: [&str; 4] = ["alloc", "string", "String", "as_mut_s
pub const STRING_AS_STR: [&str; 4] = ["alloc", "string", "String", "as_str"];
pub const STRING_NEW: [&str; 4] = ["alloc", "string", "String", "new"];
pub const STR_BYTES: [&str; 4] = ["core", "str", "<impl str>", "bytes"];
pub const STR_CHARS: [&str; 4] = ["core", "str", "<impl str>", "chars"];
pub const STR_ENDS_WITH: [&str; 4] = ["core", "str", "<impl str>", "ends_with"];
pub const STR_FROM_UTF8: [&str; 4] = ["core", "str", "converts", "from_utf8"];
pub const STR_LEN: [&str; 4] = ["core", "str", "<impl str>", "len"];
@@ -178,6 +186,7 @@ pub const TOKIO_IO_ASYNCWRITEEXT: [&str; 5] = ["tokio", "io", "util", "async_wri
pub const TRY_FROM: [&str; 4] = ["core", "convert", "TryFrom", "try_from"];
pub const VEC_AS_MUT_SLICE: [&str; 4] = ["alloc", "vec", "Vec", "as_mut_slice"];
pub const VEC_AS_SLICE: [&str; 4] = ["alloc", "vec", "Vec", "as_slice"];
pub const VEC_DEQUE_ITER: [&str; 5] = ["alloc", "collections", "vec_deque", "VecDeque", "iter"];
pub const VEC_FROM_ELEM: [&str; 3] = ["alloc", "vec", "from_elem"];
pub const VEC_NEW: [&str; 4] = ["alloc", "vec", "Vec", "new"];
pub const VEC_RESIZE: [&str; 4] = ["alloc", "vec", "Vec", "resize"];

270
clippy_utils/src/ty.rs
View File

@@ -2,19 +2,20 @@
#![allow(clippy::module_name_repetitions)]
use core::ops::ControlFlow;
use rustc_ast::ast::Mutability;
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_hir as hir;
use rustc_hir::def::{CtorKind, DefKind, Res};
use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
use rustc_hir::def_id::DefId;
use rustc_hir::{Expr, LangItem, TyKind, Unsafety};
use rustc_hir::{Expr, FnDecl, LangItem, TyKind, Unsafety};
use rustc_infer::infer::TyCtxtInferExt;
use rustc_lint::LateContext;
use rustc_middle::mir::interpret::{ConstValue, Scalar};
use rustc_middle::ty::subst::{GenericArg, GenericArgKind, Subst};
use rustc_middle::ty::{
self, AdtDef, Binder, FnSig, IntTy, ParamEnv, Predicate, PredicateKind, Ty, TyCtxt, TypeFoldable, UintTy,
VariantDiscr,
self, AdtDef, Binder, BoundRegion, DefIdTree, FnSig, IntTy, ParamEnv, Predicate, PredicateKind, ProjectionTy,
Region, RegionKind, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable, TypeVisitor, UintTy, VariantDef, VariantDiscr,
};
use rustc_span::symbol::Ident;
use rustc_span::{sym, Span, Symbol, DUMMY_SP};
@@ -501,16 +502,46 @@ pub fn all_predicates_of(tcx: TyCtxt<'_>, id: DefId) -> impl Iterator<Item = &(P
#[derive(Clone, Copy)]
pub enum ExprFnSig<'tcx> {
Sig(Binder<'tcx, FnSig<'tcx>>),
Closure(Binder<'tcx, FnSig<'tcx>>),
Closure(Option<&'tcx FnDecl<'tcx>>, Binder<'tcx, FnSig<'tcx>>),
Trait(Binder<'tcx, Ty<'tcx>>, Option<Binder<'tcx, Ty<'tcx>>>),
}
impl<'tcx> ExprFnSig<'tcx> {
/// Gets the argument type at the given offset.
pub fn input(self, i: usize) -> Binder<'tcx, Ty<'tcx>> {
/// Gets the argument type at the given offset. This will return `None` when the index is out of
/// bounds only for variadic functions, otherwise this will panic.
pub fn input(self, i: usize) -> Option<Binder<'tcx, Ty<'tcx>>> {
match self {
Self::Sig(sig) => sig.input(i),
Self::Closure(sig) => sig.input(0).map_bound(|ty| ty.tuple_fields()[i]),
Self::Trait(inputs, _) => inputs.map_bound(|ty| ty.tuple_fields()[i]),
Self::Sig(sig) => {
if sig.c_variadic() {
sig.inputs().map_bound(|inputs| inputs.get(i).copied()).transpose()
} else {
Some(sig.input(i))
}
},
Self::Closure(_, sig) => Some(sig.input(0).map_bound(|ty| ty.tuple_fields()[i])),
Self::Trait(inputs, _) => Some(inputs.map_bound(|ty| ty.tuple_fields()[i])),
}
}
/// Gets the argument type at the given offset. For closures this will also get the type as
/// written. This will return `None` when the index is out of bounds only for variadic
/// functions, otherwise this will panic.
pub fn input_with_hir(self, i: usize) -> Option<(Option<&'tcx hir::Ty<'tcx>>, Binder<'tcx, Ty<'tcx>>)> {
match self {
Self::Sig(sig) => {
if sig.c_variadic() {
sig.inputs()
.map_bound(|inputs| inputs.get(i).copied())
.transpose()
.map(|arg| (None, arg))
} else {
Some((None, sig.input(i)))
}
},
Self::Closure(decl, sig) => Some((
decl.and_then(|decl| decl.inputs.get(i)),
sig.input(0).map_bound(|ty| ty.tuple_fields()[i]),
)),
Self::Trait(inputs, _) => Some((None, inputs.map_bound(|ty| ty.tuple_fields()[i]))),
}
}
@@ -518,7 +549,7 @@ impl<'tcx> ExprFnSig<'tcx> {
/// specified.
pub fn output(self) -> Option<Binder<'tcx, Ty<'tcx>>> {
match self {
Self::Sig(sig) | Self::Closure(sig) => Some(sig.output()),
Self::Sig(sig) | Self::Closure(_, sig) => Some(sig.output()),
Self::Trait(_, output) => output,
}
}
@@ -529,74 +560,123 @@ pub fn expr_sig<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'_>) -> Option<ExprFnS
if let Res::Def(DefKind::Fn | DefKind::Ctor(_, CtorKind::Fn) | DefKind::AssocFn, id) = path_res(cx, expr) {
Some(ExprFnSig::Sig(cx.tcx.fn_sig(id)))
} else {
let ty = cx.typeck_results().expr_ty_adjusted(expr).peel_refs();
match *ty.kind() {
ty::Closure(_, subs) => Some(ExprFnSig::Closure(subs.as_closure().sig())),
ty::FnDef(id, subs) => Some(ExprFnSig::Sig(cx.tcx.bound_fn_sig(id).subst(cx.tcx, subs))),
ty::FnPtr(sig) => Some(ExprFnSig::Sig(sig)),
ty::Dynamic(bounds, _) => {
let lang_items = cx.tcx.lang_items();
match bounds.principal() {
Some(bound)
if Some(bound.def_id()) == lang_items.fn_trait()
|| Some(bound.def_id()) == lang_items.fn_once_trait()
|| Some(bound.def_id()) == lang_items.fn_mut_trait() =>
{
let output = bounds
.projection_bounds()
.find(|p| lang_items.fn_once_output().map_or(false, |id| id == p.item_def_id()))
.map(|p| p.map_bound(|p| p.term.ty().expect("return type was a const")));
Some(ExprFnSig::Trait(bound.map_bound(|b| b.substs.type_at(0)), output))
},
_ => None,
}
},
ty::Param(_) | ty::Projection(..) => {
let mut inputs = None;
let mut output = None;
let lang_items = cx.tcx.lang_items();
ty_sig(cx, cx.typeck_results().expr_ty_adjusted(expr).peel_refs())
}
}
for (pred, _) in all_predicates_of(cx.tcx, cx.typeck_results().hir_owner.to_def_id()) {
let mut is_input = false;
if let Some(ty) = pred
.kind()
.map_bound(|pred| match pred {
PredicateKind::Trait(p)
if (lang_items.fn_trait() == Some(p.def_id())
|| lang_items.fn_mut_trait() == Some(p.def_id())
|| lang_items.fn_once_trait() == Some(p.def_id()))
&& p.self_ty() == ty =>
{
is_input = true;
Some(p.trait_ref.substs.type_at(1))
},
PredicateKind::Projection(p)
if Some(p.projection_ty.item_def_id) == lang_items.fn_once_output()
&& p.projection_ty.self_ty() == ty =>
{
is_input = false;
p.term.ty()
},
_ => None,
})
.transpose()
{
if is_input && inputs.is_none() {
inputs = Some(ty);
} else if !is_input && output.is_none() {
output = Some(ty);
} else {
// Multiple different fn trait impls. Is this even allowed?
return None;
}
}
}
fn ty_sig<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'tcx>> {
match *ty.kind() {
ty::Closure(id, subs) => {
let decl = id
.as_local()
.and_then(|id| cx.tcx.hir().fn_decl_by_hir_id(cx.tcx.hir().local_def_id_to_hir_id(id)));
Some(ExprFnSig::Closure(decl, subs.as_closure().sig()))
},
ty::FnDef(id, subs) => Some(ExprFnSig::Sig(cx.tcx.bound_fn_sig(id).subst(cx.tcx, subs))),
ty::FnPtr(sig) => Some(ExprFnSig::Sig(sig)),
ty::Dynamic(bounds, _) => {
let lang_items = cx.tcx.lang_items();
match bounds.principal() {
Some(bound)
if Some(bound.def_id()) == lang_items.fn_trait()
|| Some(bound.def_id()) == lang_items.fn_once_trait()
|| Some(bound.def_id()) == lang_items.fn_mut_trait() =>
{
let output = bounds
.projection_bounds()
.find(|p| lang_items.fn_once_output().map_or(false, |id| id == p.item_def_id()))
.map(|p| p.map_bound(|p| p.term.ty().unwrap()));
Some(ExprFnSig::Trait(bound.map_bound(|b| b.substs.type_at(0)), output))
},
_ => None,
}
},
ty::Projection(proj) => match cx.tcx.try_normalize_erasing_regions(cx.param_env, ty) {
Ok(normalized_ty) if normalized_ty != ty => ty_sig(cx, normalized_ty),
_ => sig_for_projection(cx, proj).or_else(|| sig_from_bounds(cx, ty)),
},
ty::Param(_) => sig_from_bounds(cx, ty),
_ => None,
}
}
inputs.map(|ty| ExprFnSig::Trait(ty, output))
fn sig_from_bounds<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> Option<ExprFnSig<'tcx>> {
let mut inputs = None;
let mut output = None;
let lang_items = cx.tcx.lang_items();
for (pred, _) in all_predicates_of(cx.tcx, cx.typeck_results().hir_owner.to_def_id()) {
match pred.kind().skip_binder() {
PredicateKind::Trait(p)
if (lang_items.fn_trait() == Some(p.def_id())
|| lang_items.fn_mut_trait() == Some(p.def_id())
|| lang_items.fn_once_trait() == Some(p.def_id()))
&& p.self_ty() == ty =>
{
if inputs.is_some() {
// Multiple different fn trait impls. Is this even allowed?
return None;
}
inputs = Some(pred.kind().rebind(p.trait_ref.substs.type_at(1)));
},
_ => None,
PredicateKind::Projection(p)
if Some(p.projection_ty.item_def_id) == lang_items.fn_once_output()
&& p.projection_ty.self_ty() == ty =>
{
if output.is_some() {
// Multiple different fn trait impls. Is this even allowed?
return None;
}
output = Some(pred.kind().rebind(p.term.ty().unwrap()));
},
_ => (),
}
}
inputs.map(|ty| ExprFnSig::Trait(ty, output))
}
fn sig_for_projection<'tcx>(cx: &LateContext<'tcx>, ty: ProjectionTy<'tcx>) -> Option<ExprFnSig<'tcx>> {
let mut inputs = None;
let mut output = None;
let lang_items = cx.tcx.lang_items();
for pred in cx
.tcx
.bound_explicit_item_bounds(ty.item_def_id)
.transpose_iter()
.map(|x| x.map_bound(|(p, _)| p))
{
match pred.0.kind().skip_binder() {
PredicateKind::Trait(p)
if (lang_items.fn_trait() == Some(p.def_id())
|| lang_items.fn_mut_trait() == Some(p.def_id())
|| lang_items.fn_once_trait() == Some(p.def_id())) =>
{
if inputs.is_some() {
// Multiple different fn trait impls. Is this even allowed?
return None;
}
inputs = Some(
pred.map_bound(|pred| pred.kind().rebind(p.trait_ref.substs.type_at(1)))
.subst(cx.tcx, ty.substs),
);
},
PredicateKind::Projection(p) if Some(p.projection_ty.item_def_id) == lang_items.fn_once_output() => {
if output.is_some() {
// Multiple different fn trait impls. Is this even allowed?
return None;
}
output = Some(
pred.map_bound(|pred| pred.kind().rebind(p.term.ty().unwrap()))
.subst(cx.tcx, ty.substs),
);
},
_ => (),
}
}
inputs.map(|ty| ExprFnSig::Trait(ty, output))
}
#[derive(Clone, Copy)]
@@ -667,3 +747,45 @@ pub fn is_c_void(cx: &LateContext<'_>, ty: Ty<'_>) -> bool {
false
}
}
pub fn for_each_top_level_late_bound_region<B>(
ty: Ty<'_>,
f: impl FnMut(BoundRegion) -> ControlFlow<B>,
) -> ControlFlow<B> {
struct V<F> {
index: u32,
f: F,
}
impl<'tcx, B, F: FnMut(BoundRegion) -> ControlFlow<B>> TypeVisitor<'tcx> for V<F> {
type BreakTy = B;
fn visit_region(&mut self, r: Region<'tcx>) -> ControlFlow<Self::BreakTy> {
if let RegionKind::ReLateBound(idx, bound) = r.kind() && idx.as_u32() == self.index {
(self.f)(bound)
} else {
ControlFlow::Continue(())
}
}
fn visit_binder<T: TypeFoldable<'tcx>>(&mut self, t: &Binder<'tcx, T>) -> ControlFlow<Self::BreakTy> {
self.index += 1;
let res = t.super_visit_with(self);
self.index -= 1;
res
}
}
ty.visit_with(&mut V { index: 0, f })
}
/// Gets the struct or enum variant from the given `Res`
pub fn variant_of_res<'tcx>(cx: &LateContext<'tcx>, res: Res) -> Option<&'tcx VariantDef> {
match res {
Res::Def(DefKind::Struct, id) => Some(cx.tcx.adt_def(id).non_enum_variant()),
Res::Def(DefKind::Variant, id) => Some(cx.tcx.adt_def(cx.tcx.parent(id)).variant_with_id(id)),
Res::Def(DefKind::Ctor(CtorOf::Struct, _), id) => Some(cx.tcx.adt_def(cx.tcx.parent(id)).non_enum_variant()),
Res::Def(DefKind::Ctor(CtorOf::Variant, _), id) => {
let var_id = cx.tcx.parent(id);
Some(cx.tcx.adt_def(cx.tcx.parent(var_id)).variant_with_id(var_id))
},
Res::SelfCtor(id) => Some(cx.tcx.type_of(id).ty_adt_def().unwrap().non_enum_variant()),
_ => None,
}
}

131
clippy_utils/src/visitors.rs
View File

@@ -1,16 +1,18 @@
use crate::ty::needs_ordered_drop;
use crate::{get_enclosing_block, path_to_local_id};
use core::ops::ControlFlow;
use rustc_hir as hir;
use rustc_hir::def::{DefKind, Res};
use rustc_hir::def::{CtorKind, DefKind, Res};
use rustc_hir::intravisit::{self, walk_block, walk_expr, Visitor};
use rustc_hir::{
Arm, Block, BlockCheckMode, Body, BodyId, Expr, ExprKind, HirId, ItemId, ItemKind, Stmt, UnOp, UnsafeSource,
Unsafety,
Arm, Block, BlockCheckMode, Body, BodyId, Expr, ExprKind, HirId, ItemId, ItemKind, Let, QPath, Stmt, UnOp,
UnsafeSource, Unsafety,
};
use rustc_lint::LateContext;
use rustc_middle::hir::map::Map;
use rustc_middle::hir::nested_filter;
use rustc_middle::ty;
use rustc_middle::ty::adjustment::Adjust;
use rustc_middle::ty::{self, Ty, TypeckResults};
/// Convenience method for creating a `Visitor` with just `visit_expr` overridden and nested
/// bodies (i.e. closures) are visited.
@@ -494,3 +496,124 @@ pub fn for_each_local_use_after_expr<'tcx, B>(
ControlFlow::Continue(())
}
}
// Calls the given function for every unconsumed temporary created by the expression. Note the
// function is only guaranteed to be called for types which need to be dropped, but it may be called
// for other types.
pub fn for_each_unconsumed_temporary<'tcx, B>(
cx: &LateContext<'tcx>,
e: &'tcx Expr<'tcx>,
mut f: impl FnMut(Ty<'tcx>) -> ControlFlow<B>,
) -> ControlFlow<B> {
// Todo: Handle partially consumed values.
fn helper<'tcx, B>(
typeck: &'tcx TypeckResults<'tcx>,
consume: bool,
e: &'tcx Expr<'tcx>,
f: &mut impl FnMut(Ty<'tcx>) -> ControlFlow<B>,
) -> ControlFlow<B> {
if !consume
|| matches!(
typeck.expr_adjustments(e),
[adjust, ..] if matches!(adjust.kind, Adjust::Borrow(_) | Adjust::Deref(_))
)
{
match e.kind {
ExprKind::Path(QPath::Resolved(None, p))
if matches!(p.res, Res::Def(DefKind::Ctor(_, CtorKind::Const), _)) =>
{
f(typeck.expr_ty(e))?;
},
ExprKind::Path(_)
| ExprKind::Unary(UnOp::Deref, _)
| ExprKind::Index(..)
| ExprKind::Field(..)
| ExprKind::AddrOf(..) => (),
_ => f(typeck.expr_ty(e))?,
}
}
match e.kind {
ExprKind::AddrOf(_, _, e)
| ExprKind::Field(e, _)
| ExprKind::Unary(UnOp::Deref, e)
| ExprKind::Match(e, ..)
| ExprKind::Let(&Let { init: e, .. }) => {
helper(typeck, false, e, f)?;
},
ExprKind::Block(&Block { expr: Some(e), .. }, _)
| ExprKind::Box(e)
| ExprKind::Cast(e, _)
| ExprKind::Unary(_, e) => {
helper(typeck, true, e, f)?;
},
ExprKind::Call(callee, args) => {
helper(typeck, true, callee, f)?;
for arg in args {
helper(typeck, true, arg, f)?;
}
},
ExprKind::MethodCall(_, args, _) | ExprKind::Tup(args) | ExprKind::Array(args) => {
for arg in args {
helper(typeck, true, arg, f)?;
}
},
ExprKind::Index(borrowed, consumed)
| ExprKind::Assign(borrowed, consumed, _)
| ExprKind::AssignOp(_, borrowed, consumed) => {
helper(typeck, false, borrowed, f)?;
helper(typeck, true, consumed, f)?;
},
ExprKind::Binary(_, lhs, rhs) => {
helper(typeck, true, lhs, f)?;
helper(typeck, true, rhs, f)?;
},
ExprKind::Struct(_, fields, default) => {
for field in fields {
helper(typeck, true, field.expr, f)?;
}
if let Some(default) = default {
helper(typeck, false, default, f)?;
}
},
ExprKind::If(cond, then, else_expr) => {
helper(typeck, true, cond, f)?;
helper(typeck, true, then, f)?;
if let Some(else_expr) = else_expr {
helper(typeck, true, else_expr, f)?;
}
},
ExprKind::Type(e, _) => {
helper(typeck, consume, e, f)?;
},
// Either drops temporaries, jumps out of the current expression, or has no sub expression.
ExprKind::DropTemps(_)
| ExprKind::Ret(_)
| ExprKind::Break(..)
| ExprKind::Yield(..)
| ExprKind::Block(..)
| ExprKind::Loop(..)
| ExprKind::Repeat(..)
| ExprKind::Lit(_)
| ExprKind::ConstBlock(_)
| ExprKind::Closure { .. }
| ExprKind::Path(_)
| ExprKind::Continue(_)
| ExprKind::InlineAsm(_)
| ExprKind::Err => (),
}
ControlFlow::Continue(())
}
helper(cx.typeck_results(), true, e, &mut f)
}
pub fn any_temporaries_need_ordered_drop<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> bool {
for_each_unconsumed_temporary(cx, e, |ty| {
if needs_ordered_drop(cx, ty) {
ControlFlow::Break(())
} else {
ControlFlow::Continue(())
}
})
.is_break()
}