Fix clippy's missing substs

Author: oli-obk

src/tools/clippy/clippy_lints/src/derive.rs

@@ -466,12 +466,12 @@ fn check_partial_eq_without_eq<'tcx>(cx: &LateContext<'tcx>, span: Span, trait_r
         if let Some(def_id) = trait_ref.trait_def_id();
         if cx.tcx.is_diagnostic_item(sym::PartialEq, def_id);
         let param_env = param_env_for_derived_eq(cx.tcx, adt.did(), eq_trait_def_id);
-        if !implements_trait_with_env(cx.tcx, param_env, ty, eq_trait_def_id, &[]);
+        if !implements_trait_with_env(cx.tcx, param_env, ty, eq_trait_def_id, []);
         // If all of our fields implement `Eq`, we can implement `Eq` too
         if adt
             .all_fields()
             .map(|f| f.ty(cx.tcx, substs))
-            .all(|ty| implements_trait_with_env(cx.tcx, param_env, ty, eq_trait_def_id, &[]));
+            .all(|ty| implements_trait_with_env(cx.tcx, param_env, ty, eq_trait_def_id, []));
         then {
             span_lint_and_sugg(
                 cx,

src/tools/clippy/clippy_lints/src/eta_reduction.rs

@@ -119,11 +119,13 @@ impl<'tcx> LateLintPass<'tcx> for EtaReduction {
             let callee_ty_unadjusted = cx.typeck_results().expr_ty(callee).peel_refs();
             if !is_type_diagnostic_item(cx, callee_ty_unadjusted, sym::Arc);
             if !is_type_diagnostic_item(cx, callee_ty_unadjusted, sym::Rc);
+            if let ty::Closure(_, substs) = *closure_ty.kind();
             then {
                 span_lint_and_then(cx, REDUNDANT_CLOSURE, expr.span, "redundant closure", |diag| {
                     if let Some(mut snippet) = snippet_opt(cx, callee.span) {
                         if let Some(fn_mut_id) = cx.tcx.lang_items().fn_mut_trait()
-                            && implements_trait(cx, callee_ty.peel_refs(), fn_mut_id, &[])
+                            && let args = cx.tcx.erase_late_bound_regions(ty::ClosureSubsts { substs }.sig()).inputs()
+                            && implements_trait(cx, callee_ty.peel_refs(), fn_mut_id, &args.iter().copied().map(Into::into).collect::<Vec<_>>())
                             && path_to_local(callee).map_or(false, |l| local_used_after_expr(cx, l, expr))
                         {
                                 // Mutable closure is used after current expr; we cannot consume it.

src/tools/clippy/clippy_lints/src/methods/unnecessary_to_owned.rs

@@ -474,7 +474,7 @@ fn is_cow_into_owned(cx: &LateContext<'_>, method_name: Symbol, method_def_id: D
 }
 
 /// Returns true if the named method is `ToString::to_string` and it's called on a type that
-/// is string-like i.e. implements `AsRef<str>` or `Deref<str>`.
+/// is string-like i.e. implements `AsRef<str>` or `Deref<Target = str>`.
 fn is_to_string_on_string_like<'a>(
     cx: &LateContext<'_>,
     call_expr: &'a Expr<'a>,
@@ -490,7 +490,7 @@ fn is_to_string_on_string_like<'a>(
         && let GenericArgKind::Type(ty) = generic_arg.unpack()
         && let Some(deref_trait_id) = cx.tcx.get_diagnostic_item(sym::Deref)
         && let Some(as_ref_trait_id) = cx.tcx.get_diagnostic_item(sym::AsRef)
-        && (implements_trait(cx, ty, deref_trait_id, &[cx.tcx.types.str_.into()]) ||
+        && (get_associated_type(cx, ty, deref_trait_id, "Target") == Some(cx.tcx.types.str_) ||
             implements_trait(cx, ty, as_ref_trait_id, &[cx.tcx.types.str_.into()])) {
             true
         } else {

src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs

@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::{multispan_sugg, span_lint_and_then};
 use clippy_utils::ptr::get_spans;
 use clippy_utils::source::{snippet, snippet_opt};
-use clippy_utils::ty::{implements_trait, is_copy, is_type_diagnostic_item, is_type_lang_item};
+use clippy_utils::ty::{implements_trait, implements_trait_with_env, is_copy, is_type_diagnostic_item, is_type_lang_item};
 use clippy_utils::{get_trait_def_id, is_self, paths};
 use if_chain::if_chain;
 use rustc_ast::ast::Attribute;
@@ -185,7 +185,7 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
                 if !ty.is_mutable_ptr();
                 if !is_copy(cx, ty);
                 if ty.is_sized(cx.tcx, cx.param_env);
-                if !allowed_traits.iter().any(|&t| implements_trait(cx, ty, t, &[]));
+                if !allowed_traits.iter().any(|&t| implements_trait_with_env(cx.tcx, cx.param_env, ty, t, [None]));
                 if !implements_borrow_trait;
                 if !all_borrowable_trait;
 

src/tools/clippy/clippy_lints/src/neg_cmp_op_on_partial_ord.rs

@@ -65,7 +65,7 @@ impl<'tcx> LateLintPass<'tcx> for NoNegCompOpForPartialOrd {
 
                 let implements_partial_ord = {
                     if let Some(id) = cx.tcx.lang_items().partial_ord_trait() {
-                        implements_trait(cx, ty, id, &[])
+                        implements_trait(cx, ty, id, &[ty.into()])
                     } else {
                         return;
                     }

src/tools/clippy/clippy_utils/src/ty.rs

@@ -9,7 +9,7 @@ use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
 use rustc_hir::def_id::DefId;
 use rustc_hir::{Expr, FnDecl, LangItem, TyKind, Unsafety};
-use rustc_infer::infer::TyCtxtInferExt;
+use rustc_infer::infer::{TyCtxtInferExt, type_variable::{TypeVariableOrigin, TypeVariableOriginKind}};
 use rustc_lint::LateContext;
 use rustc_middle::mir::interpret::{ConstValue, Scalar};
 use rustc_middle::ty::{
@@ -18,7 +18,7 @@ use rustc_middle::ty::{
 };
 use rustc_middle::ty::{GenericArg, GenericArgKind};
 use rustc_span::symbol::Ident;
-use rustc_span::{sym, Span, Symbol};
+use rustc_span::{sym, Span, Symbol, DUMMY_SP};
 use rustc_target::abi::{Size, VariantIdx};
 use rustc_trait_selection::infer::InferCtxtExt;
 use rustc_trait_selection::traits::query::normalize::AtExt;
@@ -153,7 +153,7 @@ pub fn implements_trait<'tcx>(
     trait_id: DefId,
     ty_params: &[GenericArg<'tcx>],
 ) -> bool {
-    implements_trait_with_env(cx.tcx, cx.param_env, ty, trait_id, ty_params)
+    implements_trait_with_env(cx.tcx, cx.param_env, ty, trait_id, ty_params.iter().map(|&arg| Some(arg)))
 }
 
 /// Same as `implements_trait` but allows using a `ParamEnv` different from the lint context.
@@ -162,7 +162,7 @@ pub fn implements_trait_with_env<'tcx>(
     param_env: ParamEnv<'tcx>,
     ty: Ty<'tcx>,
     trait_id: DefId,
-    ty_params: &[GenericArg<'tcx>],
+    ty_params: impl IntoIterator<Item = Option<GenericArg<'tcx>>>,
 ) -> bool {
     // Clippy shouldn't have infer types
     assert!(!ty.needs_infer());
@@ -171,8 +171,12 @@ pub fn implements_trait_with_env<'tcx>(
     if ty.has_escaping_bound_vars() {
         return false;
     }
-    let ty_params = tcx.mk_substs(ty_params.iter());
     let infcx = tcx.infer_ctxt().build();
+    let orig = TypeVariableOrigin {
+        kind: TypeVariableOriginKind::MiscVariable,
+        span: DUMMY_SP,
+    };
+    let ty_params = tcx.mk_substs(ty_params.into_iter().map(|arg| arg.unwrap_or_else(|| infcx.next_ty_var(orig).into())));
     infcx
         .type_implements_trait(trait_id, ty, ty_params, param_env)
         .must_apply_modulo_regions()