Auto merge of #12942 - Jarcho:ex_proc_macro, r=Manishearth

Add more types to `is_from_proc_macro`

I've been running through going through all the lint implementations to clean them up. I'll be separating out the changes into small PRs to make reviewing easier.

changelog: none

clippy_lints/src/allow_attributes.rs

@@ -57,7 +57,7 @@ fn check_attribute<'cx>(&mut self, cx: &LateContext<'cx>, attr: &'cx Attribute)
             && let AttrStyle::Outer = attr.style
             && let Some(ident) = attr.ident()
             && ident.name == rustc_span::symbol::sym::allow
-            && !is_from_proc_macro(cx, &attr)
+            && !is_from_proc_macro(cx, attr)
         {
             span_lint_and_sugg(
                 cx,

clippy_lints/src/attrs/allow_attributes_without_reason.rs

@@ -22,7 +22,7 @@ pub(super) fn check<'cx>(cx: &LateContext<'cx>, name: Symbol, items: &[NestedMet
     }
 
     // Check if the attribute is in an external macro and therefore out of the developer's control
-    if in_external_macro(cx.sess(), attr.span) || is_from_proc_macro(cx, &attr) {
+    if in_external_macro(cx.sess(), attr.span) || is_from_proc_macro(cx, attr) {
         return;
     }
 

clippy_utils/src/check_proc_macro.rs

@@ -18,8 +18,8 @@
 use rustc_hir::intravisit::FnKind;
 use rustc_hir::{
     Block, BlockCheckMode, Body, Closure, Destination, Expr, ExprKind, FieldDef, FnHeader, FnRetTy, HirId, Impl,
-    ImplItem, ImplItemKind, IsAuto, Item, ItemKind, LoopSource, MatchSource, MutTy, Node, QPath, Safety, TraitItem,
-    TraitItemKind, Ty, TyKind, UnOp, UnsafeSource, Variant, VariantData, YieldSource,
+    ImplItem, ImplItemKind, IsAuto, Item, ItemKind, Lit, LoopSource, MatchSource, MutTy, Node, Path, QPath, Safety,
+    TraitItem, TraitItemKind, Ty, TyKind, UnOp, UnsafeSource, Variant, VariantData, YieldSource,
 };
 use rustc_lint::{LateContext, LintContext};
 use rustc_middle::ty::TyCtxt;
@@ -121,6 +121,26 @@ fn qpath_search_pat(path: &QPath<'_>) -> (Pat, Pat) {
     }
 }
 
+fn path_search_pat(path: &Path<'_>) -> (Pat, Pat) {
+    let (head, tail) = match path.segments {
+        [head, .., tail] => (head, tail),
+        [p] => (p, p),
+        [] => return (Pat::Str(""), Pat::Str("")),
+    };
+    (
+        if head.ident.name == kw::PathRoot {
+            Pat::Str("::")
+        } else {
+            Pat::Sym(head.ident.name)
+        },
+        if tail.args.is_some() {
+            Pat::Str(">")
+        } else {
+            Pat::Sym(tail.ident.name)
+        },
+    )
+}
+
 /// Get the search patterns to use for the given expression
 fn expr_search_pat(tcx: TyCtxt<'_>, e: &Expr<'_>) -> (Pat, Pat) {
     match e.kind {
@@ -355,19 +375,21 @@ fn ty_search_pat(ty: &Ty<'_>) -> (Pat, Pat) {
     }
 }
 
+fn ident_search_pat(ident: Ident) -> (Pat, Pat) {
+    (Pat::Sym(ident.name), Pat::Sym(ident.name))
+}
+
 pub trait WithSearchPat<'cx> {
     type Context: LintContext;
     fn search_pat(&self, cx: &Self::Context) -> (Pat, Pat);
     fn span(&self) -> Span;
 }
 macro_rules! impl_with_search_pat {
-    ($cx:ident: $ty:ident with $fn:ident $(($tcx:ident))?) => {
-        impl<'cx> WithSearchPat<'cx> for $ty<'cx> {
-            type Context = $cx<'cx>;
-            #[allow(unused_variables)]
-            fn search_pat(&self, cx: &Self::Context) -> (Pat, Pat) {
-                $(let $tcx = cx.tcx;)?
-                $fn($($tcx,)? self)
+    (($cx_ident:ident: $cx_ty:ident<$cx_lt:lifetime>, $self:tt: $ty:ty) => $fn:ident($($args:tt)*)) => {
+        impl<$cx_lt> WithSearchPat<$cx_lt> for $ty {
+            type Context = $cx_ty<$cx_lt>;
+            fn search_pat(&$self, $cx_ident: &Self::Context) -> (Pat, Pat) {
+                $fn($($args)*)
             }
             fn span(&self) -> Span {
                 self.span
@@ -375,13 +397,17 @@ fn span(&self) -> Span {
         }
     };
 }
-impl_with_search_pat!(LateContext: Expr with expr_search_pat(tcx));
-impl_with_search_pat!(LateContext: Item with item_search_pat);
-impl_with_search_pat!(LateContext: TraitItem with trait_item_search_pat);
-impl_with_search_pat!(LateContext: ImplItem with impl_item_search_pat);
-impl_with_search_pat!(LateContext: FieldDef with field_def_search_pat);
-impl_with_search_pat!(LateContext: Variant with variant_search_pat);
-impl_with_search_pat!(LateContext: Ty with ty_search_pat);
+impl_with_search_pat!((cx: LateContext<'tcx>, self: Expr<'tcx>) => expr_search_pat(cx.tcx, self));
+impl_with_search_pat!((_cx: LateContext<'tcx>, self: Item<'_>) => item_search_pat(self));
+impl_with_search_pat!((_cx: LateContext<'tcx>, self: TraitItem<'_>) => trait_item_search_pat(self));
+impl_with_search_pat!((_cx: LateContext<'tcx>, self: ImplItem<'_>) => impl_item_search_pat(self));
+impl_with_search_pat!((_cx: LateContext<'tcx>, self: FieldDef<'_>) => field_def_search_pat(self));
+impl_with_search_pat!((_cx: LateContext<'tcx>, self: Variant<'_>) => variant_search_pat(self));
+impl_with_search_pat!((_cx: LateContext<'tcx>, self: Ty<'_>) => ty_search_pat(self));
+impl_with_search_pat!((_cx: LateContext<'tcx>, self: Attribute) => attr_search_pat(self));
+impl_with_search_pat!((_cx: LateContext<'tcx>, self: Ident) => ident_search_pat(*self));
+impl_with_search_pat!((_cx: LateContext<'tcx>, self: Lit) => lit_search_pat(&self.node));
+impl_with_search_pat!((_cx: LateContext<'tcx>, self: Path<'_>) => path_search_pat(self));
 
 impl<'cx> WithSearchPat<'cx> for (&FnKind<'cx>, &Body<'cx>, HirId, Span) {
     type Context = LateContext<'cx>;
@@ -395,32 +421,6 @@ fn span(&self) -> Span {
     }
 }
 
-// `Attribute` does not have the `hir` associated lifetime, so we cannot use the macro
-impl<'cx> WithSearchPat<'cx> for &'cx Attribute {
-    type Context = LateContext<'cx>;
-
-    fn search_pat(&self, _cx: &Self::Context) -> (Pat, Pat) {
-        attr_search_pat(self)
-    }
-
-    fn span(&self) -> Span {
-        self.span
-    }
-}
-
-// `Ident` does not have the `hir` associated lifetime, so we cannot use the macro
-impl<'cx> WithSearchPat<'cx> for Ident {
-    type Context = LateContext<'cx>;
-
-    fn search_pat(&self, _cx: &Self::Context) -> (Pat, Pat) {
-        (Pat::Sym(self.name), Pat::Sym(self.name))
-    }
-
-    fn span(&self) -> Span {
-        self.span
-    }
-}
-
 /// Checks if the item likely came from a proc-macro.
 ///
 /// This should be called after `in_external_macro` and the initial pattern matching of the ast as