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Auto merge of rust-lang#7890 - Alexendoo:ptr-arg-alias, r=camsteffen
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Ignore references to type aliases in ptr_arg

Works using the fact that the hir path will point to a TyAlias, rather than being resolved to the underlying type

Fixes rust-lang#7699

changelog: [`ptr_arg`] No longer lints references to type aliases
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@bors
bors committed Oct 29, 2021
2 parents 00821ca + e2c30f0 commit dbe167d
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Showing 2 changed files with 36 additions and 21 deletions.
53 changes: 32 additions & 21 deletions clippy_lints/src/ptr.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,16 +3,16 @@
use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg, span_lint_and_then};
use clippy_utils::ptr::get_spans;
use clippy_utils::source::snippet_opt;
use clippy_utils::ty::{is_type_diagnostic_item, match_type, walk_ptrs_hir_ty};
use clippy_utils::ty::walk_ptrs_hir_ty;
use clippy_utils::{expr_path_res, is_lint_allowed, match_any_diagnostic_items, paths};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::def::Res;
use rustc_hir::{
BinOpKind, BodyId, Expr, ExprKind, FnDecl, FnRetTy, GenericArg, HirId, Impl, ImplItem, ImplItemKind, Item,
ItemKind, Lifetime, MutTy, Mutability, Node, PathSegment, QPath, TraitFn, TraitItem, TraitItemKind, Ty, TyKind,
BinOpKind, BodyId, Expr, ExprKind, FnDecl, FnRetTy, GenericArg, Impl, ImplItem, ImplItemKind, Item, ItemKind,
Lifetime, MutTy, Mutability, Node, PathSegment, QPath, TraitFn, TraitItem, TraitItemKind, Ty, TyKind,
};
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty;
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::source_map::Span;
use rustc_span::symbol::Symbol;
Expand Down Expand Up @@ -153,7 +153,7 @@ declare_lint_pass!(Ptr => [PTR_ARG, CMP_NULL, MUT_FROM_REF, INVALID_NULL_PTR_USA
impl<'tcx> LateLintPass<'tcx> for Ptr {
fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) {
if let ItemKind::Fn(ref sig, _, body_id) = item.kind {
check_fn(cx, sig.decl, item.hir_id(), Some(body_id));
check_fn(cx, sig.decl, Some(body_id));
}
}

Expand All @@ -165,7 +165,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
return; // ignore trait impls
}
}
check_fn(cx, sig.decl, item.hir_id(), Some(body_id));
check_fn(cx, sig.decl, Some(body_id));
}
}

Expand All @@ -176,7 +176,7 @@ impl<'tcx> LateLintPass<'tcx> for Ptr {
} else {
None
};
check_fn(cx, sig.decl, item.hir_id(), body_id);
check_fn(cx, sig.decl, body_id);
}
}

Expand Down Expand Up @@ -244,22 +244,31 @@ fn check_invalid_ptr_usage<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
}

#[allow(clippy::too_many_lines)]
fn check_fn(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_id: HirId, opt_body_id: Option<BodyId>) {
let fn_def_id = cx.tcx.hir().local_def_id(fn_id);
let sig = cx.tcx.fn_sig(fn_def_id);
let fn_ty = sig.skip_binder();
fn check_fn(cx: &LateContext<'_>, decl: &FnDecl<'_>, opt_body_id: Option<BodyId>) {
let body = opt_body_id.map(|id| cx.tcx.hir().body(id));

for (idx, (arg, ty)) in decl.inputs.iter().zip(fn_ty.inputs()).enumerate() {
for (idx, arg) in decl.inputs.iter().enumerate() {
// Honor the allow attribute on parameters. See issue 5644.
if let Some(body) = &body {
if is_lint_allowed(cx, PTR_ARG, body.params[idx].hir_id) {
continue;
}
}

if let ty::Ref(_, ty, Mutability::Not) = ty.kind() {
if is_type_diagnostic_item(cx, ty, sym::Vec) {
let (item_name, path) = if_chain! {
if let TyKind::Rptr(_, MutTy { ty, mutbl: Mutability::Not }) = arg.kind;
if let TyKind::Path(QPath::Resolved(_, path)) = ty.kind;
if let Res::Def(_, did) = path.res;
if let Some(item_name) = cx.tcx.get_diagnostic_name(did);
then {
(item_name, path)
} else {
continue
}
};

match item_name {
sym::Vec => {
if let Some(spans) = get_spans(cx, opt_body_id, idx, &[("clone", ".to_owned()")]) {
span_lint_and_then(
cx,
Expand Down Expand Up @@ -289,7 +298,8 @@ fn check_fn(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_id: HirId, opt_body_id:
},
);
}
} else if is_type_diagnostic_item(cx, ty, sym::String) {
},
sym::String => {
if let Some(spans) = get_spans(cx, opt_body_id, idx, &[("clone", ".to_string()"), ("as_str", "")]) {
span_lint_and_then(
cx,
Expand All @@ -311,7 +321,8 @@ fn check_fn(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_id: HirId, opt_body_id:
},
);
}
} else if is_type_diagnostic_item(cx, ty, sym::PathBuf) {
},
sym::PathBuf => {
if let Some(spans) = get_spans(cx, opt_body_id, idx, &[("clone", ".to_path_buf()"), ("as_path", "")]) {
span_lint_and_then(
cx,
Expand All @@ -338,11 +349,10 @@ fn check_fn(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_id: HirId, opt_body_id:
},
);
}
} else if match_type(cx, ty, &paths::COW) {
},
sym::Cow => {
if_chain! {
if let TyKind::Rptr(_, MutTy { ty, ..} ) = arg.kind;
if let TyKind::Path(QPath::Resolved(None, pp)) = ty.kind;
if let [ref bx] = *pp.segments;
if let [ref bx] = *path.segments;
if let Some(params) = bx.args;
if !params.parenthesized;
if let Some(inner) = params.args.iter().find_map(|arg| match arg {
Expand All @@ -363,7 +373,8 @@ fn check_fn(cx: &LateContext<'_>, decl: &FnDecl<'_>, fn_id: HirId, opt_body_id:
);
}
}
}
},
_ => {},
}
}

Expand Down
4 changes: 4 additions & 0 deletions tests/ui/ptr_arg.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -155,3 +155,7 @@ mod issue6509 {
let _ = str.clone().clone();
}
}

// No error for types behind an alias (#7699)
type A = Vec<u8>;
fn aliased(a: &A) {}

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