user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Auto merge of #4978 - mikerite:fix-4958, r=phansch

Browse source 
Fix bad `explicit_into_iter_loop` suggestion

Fixes #4958

changelog: Fix bad `explicit_into_iter_loop` suggestion
This commit is contained in:
bors 2020-01-03 05:59:19 +00:00
commit 304edf39c3
4 changed files with 108 additions and 17 deletions
Download patch file Download diff file Expand all files Collapse all files

31
clippy_lints/src/loops.rs
View file

@ -12,8 +12,7 @@ use rustc_session::declare_tool_lint;
// use rustc::middle::region::CodeExtent;
use crate::consts::{constant, Constant};
use crate::utils::usage::mutated_variables;
use crate::utils::{is_type_diagnostic_item, qpath_res, sext, sugg};
use rustc::ty::subst::Subst;
use crate::utils::{is_type_diagnostic_item, qpath_res, same_tys, sext, sugg};
use rustc::ty::{self, Ty};
use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use rustc_errors::Applicability;
@ -1344,20 +1343,9 @@ fn check_for_loop_arg(cx: &LateContext<'_, '_>, pat: &Pat<'_>, arg: &Expr<'_>, e
lint_iter_method(cx, args, arg, method_name);
}
} else if method_name == "into_iter" && match_trait_method(cx, arg, &paths::INTO_ITERATOR) {
let def_id = cx.tables.type_dependent_def_id(arg.hir_id).unwrap();
let substs = cx.tables.node_substs(arg.hir_id);
let method_type = cx.tcx.type_of(def_id).subst(cx.tcx, substs);
let fn_arg_tys = method_type.fn_sig(cx.tcx).inputs();
assert_eq!(fn_arg_tys.skip_binder().len(), 1);
if fn_arg_tys.skip_binder()[0].is_region_ptr() {
match cx.tables.expr_ty(&args[0]).kind {
// If the length is greater than 32 no traits are implemented for array and
// therefore we cannot use `&`.
ty::Array(_, size) if size.eval_usize(cx.tcx, cx.param_env) > 32 => {},
_ => lint_iter_method(cx, args, arg, method_name),
};
} else {
let receiver_ty = cx.tables.expr_ty(&args[0]);
let receiver_ty_adjusted = cx.tables.expr_ty_adjusted(&args[0]);
if same_tys(cx, receiver_ty, receiver_ty_adjusted) {
let mut applicability = Applicability::MachineApplicable;
let object = snippet_with_applicability(cx, args[0].span, "_", &mut applicability);
span_lint_and_sugg(
@ -1370,6 +1358,17 @@ fn check_for_loop_arg(cx: &LateContext<'_, '_>, pat: &Pat<'_>, arg: &Expr<'_>, e
object.to_string(),
applicability,
);
} else {
let ref_receiver_ty = cx.tcx.mk_ref(
cx.tcx.lifetimes.re_erased,
ty::TypeAndMut {
ty: receiver_ty,
mutbl: Mutability::Not,
},
);
if same_tys(cx, receiver_ty_adjusted, ref_receiver_ty) {
lint_iter_method(cx, args, arg, method_name)
}
}
} else if method_name == "next" && match_trait_method(cx, arg, &paths::ITERATOR) {
span_lint(