[clang-tools-extra] [clang-tidy] Fix false positive for cppcoreguidelines-pro-bounds-pointer-arithmetic (PR #127394)

[via cfe-commits]

https://github.com/flovent updated https://github.com/llvm/llvm-project/pull/127394

>From f7439943d138bdfee87f77a1c44b3d7d26618129 Mon Sep 17 00:00:00 2001
From: flovent <flbven at protonmail.com>
Date: Sun, 16 Feb 2025 21:07:55 +0800
Subject: [PATCH 1/4] [clang-tidy] Fix false positive for
 cppcoreguidelines-pro-bounds-pointer-arithmetic

---
 .../ProBoundsPointerArithmeticCheck.cpp       |  3 ++-
 clang-tools-extra/docs/ReleaseNotes.rst       |  4 ++++
 ...-bounds-pointer-arithmetic-issue126424.cpp | 19 +++++++++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic-issue126424.cpp

diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp
index a1494a095f5b6..0d68790349fb5 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp
@@ -42,7 +42,8 @@ void ProBoundsPointerArithmeticCheck::registerMatchers(MatchFinder *Finder) {
       arraySubscriptExpr(
           hasBase(ignoringImpCasts(
               anyOf(AllPointerTypes,
-                    hasType(decayedType(hasDecayedType(pointerType())))))))
+                    hasType(decayedType(hasDecayedType(pointerType())))))),
+          hasIndex(hasType(isInteger())))
           .bind("expr"),
       this);
 }
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 8032f0d23f494..fa644277b5afa 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -234,6 +234,10 @@ Changes in existing checks
   tolerating fix-it breaking compilation when functions is used as pointers
   to avoid matching usage of functions within the current compilation unit.
 
+- Improved :doc:`cppcoreguidelines-pro-bounds-pointer-arithmetic
+  <clang-tidy/checks/cppcoreguidelines/pro-bounds-pointer-arithmetic>` check by
+  fix false positives related to operator overloading and templates.
+
 Removed checks
 ^^^^^^^^^^^^^^
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic-issue126424.cpp b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic-issue126424.cpp
new file mode 100644
index 0000000000000..b6b7a9664f38d
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic-issue126424.cpp
@@ -0,0 +1,19 @@
+// RUN: %check_clang_tidy %s cppcoreguidelines-pro-bounds-pointer-arithmetic %t
+
+namespace std {
+template <typename, typename>
+class pair {};
+
+template <typename Key, typename Value>
+class map {
+  public:
+   using value_type = pair<Key, Value>;
+   value_type& operator[](const Key& key);
+   value_type& operator[](Key&& key);
+ };
+}
+
+template <typename R>
+int f(std::map<R*, int>& map, R* r) {
+  return map[r]; // OK
+}
\ No newline at end of file

>From c93ab7ea93f2356b6089bd4558d8e0bcfc664c18 Mon Sep 17 00:00:00 2001
From: flovent <flbven at protonmail.com>
Date: Sun, 16 Feb 2025 21:18:45 +0800
Subject: [PATCH 2/4] add missing new line for testcase

---
 .../pro-bounds-pointer-arithmetic-issue126424.cpp               | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic-issue126424.cpp b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic-issue126424.cpp
index b6b7a9664f38d..a76798423ee17 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic-issue126424.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines/pro-bounds-pointer-arithmetic-issue126424.cpp
@@ -16,4 +16,4 @@ class map {
 template <typename R>
 int f(std::map<R*, int>& map, R* r) {
   return map[r]; // OK
-}
\ No newline at end of file
+}

>From 8092d8a2c08f07b71ca72a94a5b7a2f8dcfeaa87 Mon Sep 17 00:00:00 2001
From: flovent <flbven at protomail.com>
Date: Mon, 17 Feb 2025 20:11:06 +0800
Subject: [PATCH 3/4] keep alpha order for release note

---
 clang-tools-extra/docs/ReleaseNotes.rst | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index fa644277b5afa..4d7def9b1db16 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -176,6 +176,10 @@ Changes in existing checks
   <clang-tidy/checks/concurrency/mt-unsafe>` check by fixing a false positive
   where ``strerror`` was flagged as MT-unsafe.
 
+- Improved :doc:`cppcoreguidelines-pro-bounds-pointer-arithmetic
+  <clang-tidy/checks/cppcoreguidelines/pro-bounds-pointer-arithmetic>` check by
+  fix false positives related to operator overloading and templates.
+
 - Improved :doc:`misc-const-correctness
   <clang-tidy/checks/misc/const-correctness>` check by adding the option
   `AllowedTypes`, that excludes specified types from const-correctness
@@ -234,10 +238,6 @@ Changes in existing checks
   tolerating fix-it breaking compilation when functions is used as pointers
   to avoid matching usage of functions within the current compilation unit.
 
-- Improved :doc:`cppcoreguidelines-pro-bounds-pointer-arithmetic
-  <clang-tidy/checks/cppcoreguidelines/pro-bounds-pointer-arithmetic>` check by
-  fix false positives related to operator overloading and templates.
-
 Removed checks
 ^^^^^^^^^^^^^^
 

>From 38d3f8226ee77587eacfbcb0f47ae5704a356f94 Mon Sep 17 00:00:00 2001
From: flovent <flbven at protonmail.com>
Date: Sat, 24 May 2025 18:13:09 +0800
Subject: [PATCH 4/4] optimize release notes

---
 clang-tools-extra/docs/ReleaseNotes.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 4d7def9b1db16..919625cfe87a2 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -178,7 +178,8 @@ Changes in existing checks
 
 - Improved :doc:`cppcoreguidelines-pro-bounds-pointer-arithmetic
   <clang-tidy/checks/cppcoreguidelines/pro-bounds-pointer-arithmetic>` check by
-  fix false positives related to operator overloading and templates.
+  fixing false positives when calling indexing operators that do not perform
+  pointer arithmetic in template, for example ``std::map::operator[]``.
 
 - Improved :doc:`misc-const-correctness
   <clang-tidy/checks/misc/const-correctness>` check by adding the option