https://github.com/MainakSil updated
https://github.com/llvm/llvm-project/pull/108324
>From edb6664fbdafb5127d141fde633779865a90dde1 Mon Sep 17 00:00:00 2001
From: Mainak Sil <mainaks...@gmail.com>
Date: Thu, 12 Sep 2024 08:58:15 +0530
Subject: [PATCH 1/4] Improve documentation for
bugprone-pointer-arithmetic-on-polymorphic-object
---
...inter-arithmetic-on-polymorphic-object.rst | 38 ++++++++++++++-----
1 file changed, 28 insertions(+), 10 deletions(-)
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
index 1884acd5f12b3e..4f926808f9e408 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
@@ -19,20 +19,33 @@ Example:
.. code-block:: c++
struct Base {
- virtual void ~Base();
+ virtual ~Base();
+ int i;
};
struct Derived : public Base {};
void foo() {
- Base *b = new Derived[10];
+ Base *b = new Derived[10];
- b += 1;
- // warning: pointer arithmetic on class that declares a virtual function
can
- // result in undefined behavior if the dynamic type differs from the
- // pointer type
+ b += 1;
+ // warning: pointer arithmetic on class that declares a virtual function can
+ // result in undefined behavior if the dynamic type differs from the
+ // pointer type
- delete[] static_cast<Derived*>(b);
+ delete[] static_cast<Derived*>(b);
+ }
+
+ // Another example showing array access with polymorphic objects.
+ int bar(const Derived d[]) {
+ return d[1].i; // warning due to pointer arithmetic on polymorphic object
+ }
+
+ // Making Derived final suppresses the warning
+ struct FinalDerived final : public Base {};
+
+ int baz(const FinalDerived d[]) {
+ return d[1].i; // no warning as FinalDerived is final
}
Options
@@ -50,14 +63,19 @@ Options
void bar() {
Base *b = new Base[10];
b += 1; // warning, as Base declares a virtual destructor
-
+
delete[] b;
-
+
Derived *d = new Derived[10]; // Derived overrides the destructor, and
// declares no other virtual functions
d += 1; // warning only if IgnoreVirtualDeclarationsOnly is set to false
-
+
delete[] d;
+
+ FinalDerived *f = new FinalDerived[10];
+ f += 1; // no warning, FinalDerived is final and cannot be further
derived
+
+ delete[] f;
}
References
>From c6832232a55d39bc98562537b9a357378a007227 Mon Sep 17 00:00:00 2001
From: Mainak Sil <145980094+mainak...@users.noreply.github.com>
Date: Thu, 12 Sep 2024 19:32:25 +0530
Subject: [PATCH 2/4] Update example to remove new/delete and focus on pointer
arithmetic
---
...inter-arithmetic-on-polymorphic-object.rst | 28 ++++++++++---------
1 file changed, 15 insertions(+), 13 deletions(-)
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
index 4f926808f9e408..cff997d5ada2aa 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
@@ -19,21 +19,23 @@ Example:
.. code-block:: c++
struct Base {
- virtual ~Base();
- int i;
+ virtual ~Base();
+ int i;
};
-
+
struct Derived : public Base {};
-
- void foo() {
- Base *b = new Derived[10];
-
- b += 1;
- // warning: pointer arithmetic on class that declares a virtual function can
- // result in undefined behavior if the dynamic type differs from the
- // pointer type
-
- delete[] static_cast<Derived*>(b);
+
+ // Function that takes a pointer and performs pointer arithmetic
+ void foo(Base* b) {
+ b += 1;
+ // warning: pointer arithmetic on class that declares a virtual function
can
+ // result in undefined behavior if the dynamic type differs from the
+ // pointer type
+ }
+
+ void bar() {
+ Derived d[10]; // Array of derived objects
+ foo(d); // Passing Derived pointer to foo(), which performs
arithmetic
}
// Another example showing array access with polymorphic objects.
>From 96fa8165375bf7a5c249c1e7c43a49ce67fd183e Mon Sep 17 00:00:00 2001
From: Mainak Sil <145980094+mainak...@users.noreply.github.com>
Date: Thu, 12 Sep 2024 22:58:11 +0530
Subject: [PATCH 3/4] Address maintainer feedback: remove redundant comments,
new/delete, and final example
---
...inter-arithmetic-on-polymorphic-object.rst | 27 +------------------
1 file changed, 1 insertion(+), 26 deletions(-)
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
index cff997d5ada2aa..81556b4537cb65 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
@@ -22,30 +22,18 @@ Example:
virtual ~Base();
int i;
};
-
struct Derived : public Base {};
-
- // Function that takes a pointer and performs pointer arithmetic
void foo(Base* b) {
b += 1;
// warning: pointer arithmetic on class that declares a virtual function
can
// result in undefined behavior if the dynamic type differs from the
// pointer type
}
-
- void bar() {
- Derived d[10]; // Array of derived objects
- foo(d); // Passing Derived pointer to foo(), which performs
arithmetic
- }
-
- // Another example showing array access with polymorphic objects.
int bar(const Derived d[]) {
return d[1].i; // warning due to pointer arithmetic on polymorphic object
}
-
// Making Derived final suppresses the warning
struct FinalDerived final : public Base {};
-
int baz(const FinalDerived d[]) {
return d[1].i; // no warning as FinalDerived is final
}
@@ -62,22 +50,9 @@ Options
.. code-block:: c++
- void bar() {
- Base *b = new Base[10];
+ void bar(Base b[], Derived d[]) {
b += 1; // warning, as Base declares a virtual destructor
-
- delete[] b;
-
- Derived *d = new Derived[10]; // Derived overrides the destructor, and
- // declares no other virtual functions
d += 1; // warning only if IgnoreVirtualDeclarationsOnly is set to false
-
- delete[] d;
-
- FinalDerived *f = new FinalDerived[10];
- f += 1; // no warning, FinalDerived is final and cannot be further
derived
-
- delete[] f;
}
References
>From 6605d3b12ec52b32cae4a1e94256b5016021bebb Mon Sep 17 00:00:00 2001
From: Mainak Sil <145980094+mainak...@users.noreply.github.com>
Date: Fri, 13 Sep 2024 08:57:33 +0530
Subject: [PATCH 4/4] Address maintainer feedback: whitespace
---
.../bugprone/pointer-arithmetic-on-polymorphic-object.rst | 5 +++++
1 file changed, 5 insertions(+)
diff --git
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
index 81556b4537cb65..95509ef3c724de 100644
---
a/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
+++
b/clang-tools-extra/docs/clang-tidy/checks/bugprone/pointer-arithmetic-on-polymorphic-object.rst
@@ -22,18 +22,23 @@ Example:
virtual ~Base();
int i;
};
+
struct Derived : public Base {};
+
void foo(Base* b) {
b += 1;
// warning: pointer arithmetic on class that declares a virtual function
can
// result in undefined behavior if the dynamic type differs from the
// pointer type
}
+
int bar(const Derived d[]) {
return d[1].i; // warning due to pointer arithmetic on polymorphic object
}
+
// Making Derived final suppresses the warning
struct FinalDerived final : public Base {};
+
int baz(const FinalDerived d[]) {
return d[1].i; // no warning as FinalDerived is final
}
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