[clang-tools-extra] [clang-tidy]add new check `bugprone-compare-pointer-to-member-virtual-function` (PR #66055)

[via cfe-commits]

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@@ -0,0 +1,90 @@
+// RUN: %check_clang_tidy %s bugprone-compare-pointer-to-member-virtual-function %t
+
+struct A {
+  virtual ~A();
+  void f1();
+  void f2();
+  virtual void f3();
+  virtual void f4();
+
+  void g1(int);
+};
+
+bool Result;
+
+void base() {
+  Result = (&A::f1 == &A::f2);
+
+  Result = (&A::f1 == &A::f3);
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+
+  Result = (&A::f1 != &A::f3);
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+
+  Result = (&A::f3 == nullptr);
+
+  Result = (&A::f3 == &A::f4);
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+
+  void (A::*V1)() = &A::f3;
+  Result = (V1 == &A::f1);
+  // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+  // CHECK-MESSAGES: :7:3: note: potential member virtual function is declared here.
+  // CHECK-MESSAGES: :8:3: note: potential member virtual function is declared here.
+  Result = (&A::f1 == V1);
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+  // CHECK-MESSAGES: :7:3: note: potential member virtual function is declared here.
+  // CHECK-MESSAGES: :8:3: note: potential member virtual function is declared here.
+
+  auto& V2 = V1;
+  Result = (&A::f1 == V2);
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+  // CHECK-MESSAGES: :7:3: note: potential member virtual function is declared here.
+  // CHECK-MESSAGES: :8:3: note: potential member virtual function is declared here.
+
+  void (A::*V3)(int) = &A::g1;
+  Result = (V3 == &A::g1);
+  Result = (&A::g1 == V3);
+}
+
+using B = A;
+void usingRecordName() {
+  Result = (&B::f1 == &B::f3);
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+
+  void (B::*V1)() = &B::f1;
+  Result = (V1 == &B::f1);
+  // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+  // CHECK-MESSAGES: :7:3: note: potential member virtual function is declared here.
+  // CHECK-MESSAGES: :8:3: note: potential member virtual function is declared here.
+}
+
+
+typedef A C;
+void typedefRecordName() {
+  Result = (&C::f1 == &C::f3);
+  // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+
+  void (C::*V1)() = &C::f1;
+  Result = (V1 == &C::f1);
+  // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+  // CHECK-MESSAGES: :7:3: note: potential member virtual function is declared here.
+  // CHECK-MESSAGES: :8:3: note: potential member virtual function is declared here.
+}
+
+
+struct A1 : public A {
+};
+
+void inheritClass() {
+  Result = (&A1::f1 == &A1::f3);
+  // CHECK-MESSAGES: :[[@LINE-1]]:21: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+
+  void (A1::*V1)() = &A1::f1;
+  Result = (V1 == &A1::f1);
+  // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: comparing a pointer to member virtual function with other pointer is unspecified behavior, only compare it with a null-pointer constant for equality.
+  // CHECK-MESSAGES: :7:3: note: potential member virtual function is declared here.
+  // CHECK-MESSAGES: :8:3: note: potential member virtual function is declared here.
+}
+
----------------
EugeneZelenko wrote:

Ditto and below.

https://github.com/llvm/llvm-project/pull/66055