fix [empty_docs] trigger in proc-macro

Author: J-ZhengLi

clippy_lints/src/doc/mod.rs

@@ -14,7 +14,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{AnonConst, Expr};
-use rustc_lint::{LateContext, LateLintPass};
+use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty;
@@ -523,7 +523,11 @@ struct DocHeaders {
 /// Others are checked elsewhere, e.g. in `check_doc` if they need access to markdown, or
 /// back in the various late lint pass methods if they need the final doc headers, like "Safety" or
 /// "Panics" sections.
-fn check_attrs(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, attrs: &[Attribute]) -> Option<DocHeaders> {
+fn check_attrs<'cx>(
+    cx: &LateContext<'cx>,
+    valid_idents: &FxHashSet<String>,
+    attrs: &'cx [Attribute],
+) -> Option<DocHeaders> {
     /// We don't want the parser to choke on intra doc links. Since we don't
     /// actually care about rendering them, just pretend that all broken links
     /// point to a fake address.
@@ -538,7 +542,16 @@ fn check_attrs(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, attrs: &[
 
     suspicious_doc_comments::check(cx, attrs);
 
-    let (fragments, _) = attrs_to_doc_fragments(attrs.iter().map(|attr| (attr, None)), true);
+    let (fragments, _) = attrs_to_doc_fragments(
+        attrs.iter().filter_map(|attr| {
+            if in_external_macro(cx.sess(), attr.span) {
+                None
+            } else {
+                Some((attr, None))
+            }
+        }),
+        true,
+    );
     let mut doc = fragments.iter().fold(String::new(), |mut acc, fragment| {
         add_doc_fragment(&mut acc, fragment);
         acc

tests/ui/empty_docs.stderr

@@ -73,23 +73,5 @@ LL |         ///
    |
    = help: consider removing or filling it
 
-error: empty doc comment
-  --> tests/ui/empty_docs.rs:77:5
-   |
-LL |     #[with_empty_docs]
-   |     ^^^^^^^^^^^^^^^^^^
-   |
-   = help: consider removing or filling it
-   = note: this error originates in the attribute macro `with_empty_docs` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-error: empty doc comment
-  --> tests/ui/empty_docs.rs:82:5
-   |
-LL |     #[with_empty_docs]
-   |     ^^^^^^^^^^^^^^^^^^
-   |
-   = help: consider removing or filling it
-   = note: this error originates in the attribute macro `with_empty_docs` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-error: aborting due to 11 previous errors
+error: aborting due to 9 previous errors