From c9a97e1f829a616f7f1be44c40159788fd9dd931 Mon Sep 17 00:00:00 2001
From: donkomura <koiru3822fs@gmail.com>
Date: Wed, 4 Jun 2025 23:15:46 +0900
Subject: [PATCH] Do not lint macro generated codes

`disallowed_names` was used to lint code generated by macros.
This behavior can confuse programmers who did not write the macro
themselves. This change suppresses lints for code originating from
macros, including external ones.

changelog: [`disallowed_names`] do not lint macro generated codes
---
 clippy_lints/src/disallowed_names.rs |  4 +++-
 tests/ui/disallowed_names.rs         | 15 +++++++++++++++
 tests/ui/disallowed_names.stderr     | 28 ++++++++++++++--------------
 3 files changed, 32 insertions(+), 15 deletions(-)

diff --git a/clippy_lints/src/disallowed_names.rs b/clippy_lints/src/disallowed_names.rs
index f55b0cf1c503..566aa12b08f5 100644
--- a/clippy_lints/src/disallowed_names.rs
+++ b/clippy_lints/src/disallowed_names.rs
@@ -1,6 +1,6 @@
 use clippy_config::Conf;
 use clippy_utils::diagnostics::span_lint;
-use clippy_utils::is_in_test;
+use clippy_utils::{is_from_proc_macro, is_in_test};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir::{Pat, PatKind};
 use rustc_lint::{LateContext, LateLintPass};
@@ -43,8 +43,10 @@ impl_lint_pass!(DisallowedNames => [DISALLOWED_NAMES]);
 impl<'tcx> LateLintPass<'tcx> for DisallowedNames {
     fn check_pat(&mut self, cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) {
         if let PatKind::Binding(.., ident, _) = pat.kind
+            && !ident.span.from_expansion()
             && self.disallow.contains(&ident.name)
             && !is_in_test(cx.tcx, pat.hir_id)
+            && !is_from_proc_macro(cx, &ident)
         {
             span_lint(
                 cx,
diff --git a/tests/ui/disallowed_names.rs b/tests/ui/disallowed_names.rs
index 30fbdbc1fdc8..15bb67349976 100644
--- a/tests/ui/disallowed_names.rs
+++ b/tests/ui/disallowed_names.rs
@@ -1,3 +1,4 @@
+//@aux-build:proc_macros.rs
 #![allow(
     dead_code,
     clippy::needless_if,
@@ -9,6 +10,9 @@
 )]
 #![warn(clippy::disallowed_names)]
 
+extern crate proc_macros;
+use proc_macros::{external, with_span};
+
 fn test(foo: ()) {}
 //~^ disallowed_names
 
@@ -66,6 +70,17 @@ fn issue_1647_ref_mut() {
     //~^ disallowed_names
 }
 
+pub fn issue_14958_proc_macro() {
+    // does not lint macro-generated code
+    external! {
+        let foo = 0;
+    }
+    with_span! {
+        span
+        let foo = 0;
+    }
+}
+
 #[cfg(test)]
 mod tests {
     fn issue_7305() {
diff --git a/tests/ui/disallowed_names.stderr b/tests/ui/disallowed_names.stderr
index 09398ebbab77..b43d1b3ebfa3 100644
--- a/tests/ui/disallowed_names.stderr
+++ b/tests/ui/disallowed_names.stderr
@@ -1,5 +1,5 @@
 error: use of a disallowed/placeholder name `foo`
-  --> tests/ui/disallowed_names.rs:12:9
+  --> tests/ui/disallowed_names.rs:16:9
    |
 LL | fn test(foo: ()) {}
    |         ^^^
@@ -8,79 +8,79 @@ LL | fn test(foo: ()) {}
    = help: to override `-D warnings` add `#[allow(clippy::disallowed_names)]`
 
 error: use of a disallowed/placeholder name `foo`
-  --> tests/ui/disallowed_names.rs:16:9
+  --> tests/ui/disallowed_names.rs:20:9
    |
 LL |     let foo = 42;
    |         ^^^
 
 error: use of a disallowed/placeholder name `baz`
-  --> tests/ui/disallowed_names.rs:19:9
+  --> tests/ui/disallowed_names.rs:23:9
    |
 LL |     let baz = 42;
    |         ^^^
 
 error: use of a disallowed/placeholder name `quux`
-  --> tests/ui/disallowed_names.rs:22:9
+  --> tests/ui/disallowed_names.rs:26:9
    |
 LL |     let quux = 42;
    |         ^^^^
 
 error: use of a disallowed/placeholder name `foo`
-  --> tests/ui/disallowed_names.rs:35:10
+  --> tests/ui/disallowed_names.rs:39:10
    |
 LL |         (foo, Some(baz), quux @ Some(_)) => (),
    |          ^^^
 
 error: use of a disallowed/placeholder name `baz`
-  --> tests/ui/disallowed_names.rs:35:20
+  --> tests/ui/disallowed_names.rs:39:20
    |
 LL |         (foo, Some(baz), quux @ Some(_)) => (),
    |                    ^^^
 
 error: use of a disallowed/placeholder name `quux`
-  --> tests/ui/disallowed_names.rs:35:26
+  --> tests/ui/disallowed_names.rs:39:26
    |
 LL |         (foo, Some(baz), quux @ Some(_)) => (),
    |                          ^^^^
 
 error: use of a disallowed/placeholder name `foo`
-  --> tests/ui/disallowed_names.rs:43:19
+  --> tests/ui/disallowed_names.rs:47:19
    |
 LL | fn issue_1647(mut foo: u8) {
    |                   ^^^
 
 error: use of a disallowed/placeholder name `baz`
-  --> tests/ui/disallowed_names.rs:46:13
+  --> tests/ui/disallowed_names.rs:50:13
    |
 LL |     let mut baz = 0;
    |             ^^^
 
 error: use of a disallowed/placeholder name `quux`
-  --> tests/ui/disallowed_names.rs:49:21
+  --> tests/ui/disallowed_names.rs:53:21
    |
 LL |     if let Some(mut quux) = Some(42) {}
    |                     ^^^^
 
 error: use of a disallowed/placeholder name `baz`
-  --> tests/ui/disallowed_names.rs:54:13
+  --> tests/ui/disallowed_names.rs:58:13
    |
 LL |     let ref baz = 0;
    |             ^^^
 
 error: use of a disallowed/placeholder name `quux`
-  --> tests/ui/disallowed_names.rs:57:21
+  --> tests/ui/disallowed_names.rs:61:21
    |
 LL |     if let Some(ref quux) = Some(42) {}
    |                     ^^^^
 
 error: use of a disallowed/placeholder name `baz`
-  --> tests/ui/disallowed_names.rs:62:17
+  --> tests/ui/disallowed_names.rs:66:17
    |
 LL |     let ref mut baz = 0;
    |                 ^^^
 
 error: use of a disallowed/placeholder name `quux`
-  --> tests/ui/disallowed_names.rs:65:25
+  --> tests/ui/disallowed_names.rs:69:25
    |
 LL |     if let Some(ref mut quux) = Some(42) {}
    |                         ^^^^