From 178f5029705b7713829b3435c0d933cfb6c303ed Mon Sep 17 00:00:00 2001
From: "S. van Dijk" <pyhrr0@protonmail.com>
Date: Sun, 11 Sep 2022 20:15:35 +0200
Subject: [PATCH 1/3] Stop lint from checking code expanded from macros.

---
 clippy_lints/src/almost_complete_letter_range.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/clippy_lints/src/almost_complete_letter_range.rs b/clippy_lints/src/almost_complete_letter_range.rs
index 59a7c535400..2036dca0032 100644
--- a/clippy_lints/src/almost_complete_letter_range.rs
+++ b/clippy_lints/src/almost_complete_letter_range.rs
@@ -79,6 +79,7 @@ fn check_range(cx: &EarlyContext<'_>, span: Span, start: &Expr, end: &Expr, sugg
             (LitKind::Byte(b'a') | LitKind::Char('a'), LitKind::Byte(b'z') | LitKind::Char('z'))
             | (LitKind::Byte(b'A') | LitKind::Char('A'), LitKind::Byte(b'Z') | LitKind::Char('Z'))
         )
+        && !span.from_expansion()
     {
         span_lint_and_then(
             cx,

From 4a6f7abeebfa5c462458b788ccd122841408f062 Mon Sep 17 00:00:00 2001
From: "S. van Dijk" <pyhrr0@protonmail.com>
Date: Mon, 12 Sep 2022 10:44:44 +0200
Subject: [PATCH 2/3] Add test.

---
 tests/ui/almost_complete_letter_range.fixed  |  7 ++++++
 tests/ui/almost_complete_letter_range.rs     |  7 ++++++
 tests/ui/almost_complete_letter_range.stderr | 24 ++++++++++----------
 3 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/tests/ui/almost_complete_letter_range.fixed b/tests/ui/almost_complete_letter_range.fixed
index e69b40f35f4..0e3f644ca45 100644
--- a/tests/ui/almost_complete_letter_range.fixed
+++ b/tests/ui/almost_complete_letter_range.fixed
@@ -14,6 +14,12 @@ macro_rules! a {
     };
 }
 
+macro_rules! b {
+    () => {
+        let _ = 'a'..'z';
+    };
+}
+
 fn main() {
     #[rustfmt::skip]
     {
@@ -31,6 +37,7 @@ fn main() {
     let _ = b'B'..b'Z';
 
     let _ = a!()..='z';
+    b!();
 
     let _ = match 0u8 {
         b'a'..=b'z' if true => 1,
diff --git a/tests/ui/almost_complete_letter_range.rs b/tests/ui/almost_complete_letter_range.rs
index f2240981d45..60402bf39ed 100644
--- a/tests/ui/almost_complete_letter_range.rs
+++ b/tests/ui/almost_complete_letter_range.rs
@@ -14,6 +14,12 @@ macro_rules! a {
     };
 }
 
+macro_rules! b {
+    () => {
+        let _ = 'a'..'z';
+    };
+}
+
 fn main() {
     #[rustfmt::skip]
     {
@@ -31,6 +37,7 @@ fn main() {
     let _ = b'B'..b'Z';
 
     let _ = a!()..'z';
+    b!();
 
     let _ = match 0u8 {
         b'a'..b'z' if true => 1,
diff --git a/tests/ui/almost_complete_letter_range.stderr b/tests/ui/almost_complete_letter_range.stderr
index 5b5dc40ee54..71acae690d3 100644
--- a/tests/ui/almost_complete_letter_range.stderr
+++ b/tests/ui/almost_complete_letter_range.stderr
@@ -1,5 +1,5 @@
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:20:17
+  --> $DIR/almost_complete_letter_range.rs:26:17
    |
 LL |         let _ = ('a') ..'z';
    |                 ^^^^^^--^^^
@@ -9,7 +9,7 @@ LL |         let _ = ('a') ..'z';
    = note: `-D clippy::almost-complete-letter-range` implied by `-D warnings`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:21:17
+  --> $DIR/almost_complete_letter_range.rs:27:17
    |
 LL |         let _ = 'A' .. ('Z');
    |                 ^^^^--^^^^^^
@@ -17,7 +17,7 @@ LL |         let _ = 'A' .. ('Z');
    |                     help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:27:13
+  --> $DIR/almost_complete_letter_range.rs:33:13
    |
 LL |     let _ = (b'a')..(b'z');
    |             ^^^^^^--^^^^^^
@@ -25,7 +25,7 @@ LL |     let _ = (b'a')..(b'z');
    |                   help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:28:13
+  --> $DIR/almost_complete_letter_range.rs:34:13
    |
 LL |     let _ = b'A'..b'Z';
    |             ^^^^--^^^^
@@ -33,7 +33,7 @@ LL |     let _ = b'A'..b'Z';
    |                 help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:33:13
+  --> $DIR/almost_complete_letter_range.rs:39:13
    |
 LL |     let _ = a!()..'z';
    |             ^^^^--^^^
@@ -41,7 +41,7 @@ LL |     let _ = a!()..'z';
    |                 help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:36:9
+  --> $DIR/almost_complete_letter_range.rs:43:9
    |
 LL |         b'a'..b'z' if true => 1,
    |         ^^^^--^^^^
@@ -49,7 +49,7 @@ LL |         b'a'..b'z' if true => 1,
    |             help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:37:9
+  --> $DIR/almost_complete_letter_range.rs:44:9
    |
 LL |         b'A'..b'Z' if true => 2,
    |         ^^^^--^^^^
@@ -57,7 +57,7 @@ LL |         b'A'..b'Z' if true => 2,
    |             help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:44:9
+  --> $DIR/almost_complete_letter_range.rs:51:9
    |
 LL |         'a'..'z' if true => 1,
    |         ^^^--^^^
@@ -65,7 +65,7 @@ LL |         'a'..'z' if true => 1,
    |            help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:45:9
+  --> $DIR/almost_complete_letter_range.rs:52:9
    |
 LL |         'A'..'Z' if true => 2,
    |         ^^^--^^^
@@ -73,7 +73,7 @@ LL |         'A'..'Z' if true => 2,
    |            help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:55:9
+  --> $DIR/almost_complete_letter_range.rs:62:9
    |
 LL |         'a'..'z' => 1,
    |         ^^^--^^^
@@ -81,7 +81,7 @@ LL |         'a'..'z' => 1,
    |            help: use an inclusive range: `...`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:62:13
+  --> $DIR/almost_complete_letter_range.rs:69:13
    |
 LL |     let _ = 'a'..'z';
    |             ^^^--^^^
@@ -89,7 +89,7 @@ LL |     let _ = 'a'..'z';
    |                help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:64:9
+  --> $DIR/almost_complete_letter_range.rs:71:9
    |
 LL |         'a'..'z' => 1,
    |         ^^^--^^^

From 69c7d2cca29f6810744714bbd2c15cbe166c0741 Mon Sep 17 00:00:00 2001
From: "S. van Dijk" <pyhrr0@protonmail.com>
Date: Tue, 13 Sep 2022 09:51:32 +0200
Subject: [PATCH 3/3] Only ignore external macros.

---
 .../src/almost_complete_letter_range.rs       |  3 +-
 tests/ui/almost_complete_letter_range.fixed   | 10 ++++-
 tests/ui/almost_complete_letter_range.rs      |  8 +++-
 tests/ui/almost_complete_letter_range.stderr  | 39 ++++++++++++-------
 tests/ui/auxiliary/macro_rules.rs             |  7 ++++
 5 files changed, 50 insertions(+), 17 deletions(-)

diff --git a/clippy_lints/src/almost_complete_letter_range.rs b/clippy_lints/src/almost_complete_letter_range.rs
index 2036dca0032..073e4af1318 100644
--- a/clippy_lints/src/almost_complete_letter_range.rs
+++ b/clippy_lints/src/almost_complete_letter_range.rs
@@ -4,6 +4,7 @@ use clippy_utils::{meets_msrv, msrvs};
 use rustc_ast::ast::{Expr, ExprKind, LitKind, Pat, PatKind, RangeEnd, RangeLimits};
 use rustc_errors::Applicability;
 use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
 use rustc_semver::RustcVersion;
 use rustc_session::{declare_tool_lint, impl_lint_pass};
 use rustc_span::Span;
@@ -79,7 +80,7 @@ fn check_range(cx: &EarlyContext<'_>, span: Span, start: &Expr, end: &Expr, sugg
             (LitKind::Byte(b'a') | LitKind::Char('a'), LitKind::Byte(b'z') | LitKind::Char('z'))
             | (LitKind::Byte(b'A') | LitKind::Char('A'), LitKind::Byte(b'Z') | LitKind::Char('Z'))
         )
-        && !span.from_expansion()
+        && !in_external_macro(cx.sess(), span)
     {
         span_lint_and_then(
             cx,
diff --git a/tests/ui/almost_complete_letter_range.fixed b/tests/ui/almost_complete_letter_range.fixed
index 0e3f644ca45..079b7c000dc 100644
--- a/tests/ui/almost_complete_letter_range.fixed
+++ b/tests/ui/almost_complete_letter_range.fixed
@@ -1,5 +1,6 @@
 // run-rustfix
 // edition:2018
+// aux-build:macro_rules.rs
 
 #![feature(custom_inner_attributes)]
 #![feature(exclusive_range_pattern)]
@@ -8,6 +9,9 @@
 #![allow(ellipsis_inclusive_range_patterns)]
 #![allow(clippy::needless_parens_on_range_literals)]
 
+#[macro_use]
+extern crate macro_rules;
+
 macro_rules! a {
     () => {
         'a'
@@ -16,7 +20,7 @@ macro_rules! a {
 
 macro_rules! b {
     () => {
-        let _ = 'a'..'z';
+        let _ = 'a'..='z';
     };
 }
 
@@ -37,7 +41,6 @@ fn main() {
     let _ = b'B'..b'Z';
 
     let _ = a!()..='z';
-    b!();
 
     let _ = match 0u8 {
         b'a'..=b'z' if true => 1,
@@ -54,6 +57,9 @@ fn main() {
         'B'..'Z' => 4,
         _ => 5,
     };
+
+    almost_complete_letter_range!();
+    b!();
 }
 
 fn _under_msrv() {
diff --git a/tests/ui/almost_complete_letter_range.rs b/tests/ui/almost_complete_letter_range.rs
index 60402bf39ed..a66900a976e 100644
--- a/tests/ui/almost_complete_letter_range.rs
+++ b/tests/ui/almost_complete_letter_range.rs
@@ -1,5 +1,6 @@
 // run-rustfix
 // edition:2018
+// aux-build:macro_rules.rs
 
 #![feature(custom_inner_attributes)]
 #![feature(exclusive_range_pattern)]
@@ -8,6 +9,9 @@
 #![allow(ellipsis_inclusive_range_patterns)]
 #![allow(clippy::needless_parens_on_range_literals)]
 
+#[macro_use]
+extern crate macro_rules;
+
 macro_rules! a {
     () => {
         'a'
@@ -37,7 +41,6 @@ fn main() {
     let _ = b'B'..b'Z';
 
     let _ = a!()..'z';
-    b!();
 
     let _ = match 0u8 {
         b'a'..b'z' if true => 1,
@@ -54,6 +57,9 @@ fn main() {
         'B'..'Z' => 4,
         _ => 5,
     };
+
+    almost_complete_letter_range!();
+    b!();
 }
 
 fn _under_msrv() {
diff --git a/tests/ui/almost_complete_letter_range.stderr b/tests/ui/almost_complete_letter_range.stderr
index 71acae690d3..3de44c72c1b 100644
--- a/tests/ui/almost_complete_letter_range.stderr
+++ b/tests/ui/almost_complete_letter_range.stderr
@@ -1,5 +1,5 @@
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:26:17
+  --> $DIR/almost_complete_letter_range.rs:30:17
    |
 LL |         let _ = ('a') ..'z';
    |                 ^^^^^^--^^^
@@ -9,7 +9,7 @@ LL |         let _ = ('a') ..'z';
    = note: `-D clippy::almost-complete-letter-range` implied by `-D warnings`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:27:17
+  --> $DIR/almost_complete_letter_range.rs:31:17
    |
 LL |         let _ = 'A' .. ('Z');
    |                 ^^^^--^^^^^^
@@ -17,7 +17,7 @@ LL |         let _ = 'A' .. ('Z');
    |                     help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:33:13
+  --> $DIR/almost_complete_letter_range.rs:37:13
    |
 LL |     let _ = (b'a')..(b'z');
    |             ^^^^^^--^^^^^^
@@ -25,7 +25,7 @@ LL |     let _ = (b'a')..(b'z');
    |                   help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:34:13
+  --> $DIR/almost_complete_letter_range.rs:38:13
    |
 LL |     let _ = b'A'..b'Z';
    |             ^^^^--^^^^
@@ -33,7 +33,7 @@ LL |     let _ = b'A'..b'Z';
    |                 help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:39:13
+  --> $DIR/almost_complete_letter_range.rs:43:13
    |
 LL |     let _ = a!()..'z';
    |             ^^^^--^^^
@@ -41,7 +41,7 @@ LL |     let _ = a!()..'z';
    |                 help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:43:9
+  --> $DIR/almost_complete_letter_range.rs:46:9
    |
 LL |         b'a'..b'z' if true => 1,
    |         ^^^^--^^^^
@@ -49,7 +49,7 @@ LL |         b'a'..b'z' if true => 1,
    |             help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:44:9
+  --> $DIR/almost_complete_letter_range.rs:47:9
    |
 LL |         b'A'..b'Z' if true => 2,
    |         ^^^^--^^^^
@@ -57,7 +57,7 @@ LL |         b'A'..b'Z' if true => 2,
    |             help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:51:9
+  --> $DIR/almost_complete_letter_range.rs:54:9
    |
 LL |         'a'..'z' if true => 1,
    |         ^^^--^^^
@@ -65,7 +65,7 @@ LL |         'a'..'z' if true => 1,
    |            help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:52:9
+  --> $DIR/almost_complete_letter_range.rs:55:9
    |
 LL |         'A'..'Z' if true => 2,
    |         ^^^--^^^
@@ -73,7 +73,20 @@ LL |         'A'..'Z' if true => 2,
    |            help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:62:9
+  --> $DIR/almost_complete_letter_range.rs:23:17
+   |
+LL |         let _ = 'a'..'z';
+   |                 ^^^--^^^
+   |                    |
+   |                    help: use an inclusive range: `..=`
+...
+LL |     b!();
+   |     ---- in this macro invocation
+   |
+   = note: this error originates in the macro `b` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: almost complete ascii letter range
+  --> $DIR/almost_complete_letter_range.rs:68:9
    |
 LL |         'a'..'z' => 1,
    |         ^^^--^^^
@@ -81,7 +94,7 @@ LL |         'a'..'z' => 1,
    |            help: use an inclusive range: `...`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:69:13
+  --> $DIR/almost_complete_letter_range.rs:75:13
    |
 LL |     let _ = 'a'..'z';
    |             ^^^--^^^
@@ -89,12 +102,12 @@ LL |     let _ = 'a'..'z';
    |                help: use an inclusive range: `..=`
 
 error: almost complete ascii letter range
-  --> $DIR/almost_complete_letter_range.rs:71:9
+  --> $DIR/almost_complete_letter_range.rs:77:9
    |
 LL |         'a'..'z' => 1,
    |         ^^^--^^^
    |            |
    |            help: use an inclusive range: `..=`
 
-error: aborting due to 12 previous errors
+error: aborting due to 13 previous errors
 
diff --git a/tests/ui/auxiliary/macro_rules.rs b/tests/ui/auxiliary/macro_rules.rs
index 83a0af6b87a..ef3ca9aea38 100644
--- a/tests/ui/auxiliary/macro_rules.rs
+++ b/tests/ui/auxiliary/macro_rules.rs
@@ -140,3 +140,10 @@ macro_rules! manual_rem_euclid {
 macro_rules! equatable_if_let {
     ($a:ident) => {{ if let 2 = $a {} }};
 }
+
+#[macro_export]
+macro_rules! almost_complete_letter_range {
+    () => {
+        let _ = 'a'..'z';
+    };
+}