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// RUN: %check_clang_tidy %s bugprone-pointer-arithmetic-on-polymorphic-object %t --
class Base {
public:
virtual ~Base() {}
};
class Derived : public Base {};
class FinalDerived final : public Base {};
class AbstractBase {
public:
virtual void f() = 0;
virtual ~AbstractBase() {}
};
class AbstractInherited : public AbstractBase {};
class AbstractOverride : public AbstractInherited {
public:
void f() override {}
};
void operators() {
Base *b = new Derived[10];
b += 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'Base' can result in undefined behavior if the dynamic type differs from the pointer type [bugprone-pointer-arithmetic-on-polymorphic-object]
b = b + 1;
// CHECK-MESSAGES: :[[@LINE-1]]:7: warning: pointer arithmetic on polymorphic object of type 'Base' can result in undefined behavior if the dynamic type differs from the pointer type [bugprone-pointer-arithmetic-on-polymorphic-object]
b++;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'Base' can result in undefined behavior if the dynamic type differs from the pointer type [bugprone-pointer-arithmetic-on-polymorphic-object]
--b;
// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: pointer arithmetic on polymorphic object of type 'Base' can result in undefined behavior if the dynamic type differs from the pointer type [bugprone-pointer-arithmetic-on-polymorphic-object]
b[1];
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'Base' can result in undefined behavior if the dynamic type differs from the pointer type [bugprone-pointer-arithmetic-on-polymorphic-object]
delete[] static_cast<Derived*>(b);
}
void subclassWarnings() {
Base *b = new Base[10];
// False positive that's impossible to distinguish without
// path-sensitive analysis, but the code is bug-prone regardless.
b += 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'Base'
delete[] b;
// Common false positive is a class that overrides all parent functions.
// Is a warning because of the check configuration.
Derived *d = new Derived[10];
d += 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'Derived'
delete[] d;
// Final classes cannot have a dynamic type.
FinalDerived *fd = new FinalDerived[10];
fd += 1;
// no-warning
delete[] fd;
}
void abstractWarnings() {
// Classes with an abstract member funtion are always matched.
AbstractBase *ab = new AbstractOverride[10];
ab += 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'AbstractBase'
delete[] static_cast<AbstractOverride*>(ab);
AbstractInherited *ai = new AbstractOverride[10];
ai += 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'AbstractInherited'
delete[] static_cast<AbstractOverride*>(ai);
// Is a warning because of the check configuration.
AbstractOverride *ao = new AbstractOverride[10];
ao += 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'AbstractOverride'
delete[] ao;
}
template <typename T>
void templateWarning(T *t) {
// FIXME: Tidy doesn't support template instantiation locations properly.
t += 1;
// no-warning
}
void functionArgument(Base *b) {
b += 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'Base'
templateWarning(b);
}
using BaseAlias = Base;
using DerivedAlias = Derived;
using FinalDerivedAlias = FinalDerived;
using BasePtr = Base*;
using DerivedPtr = Derived*;
using FinalDerivedPtr = FinalDerived*;
void typeAliases(BaseAlias *b, DerivedAlias *d, FinalDerivedAlias *fd,
BasePtr bp, DerivedPtr dp, FinalDerivedPtr fdp) {
b += 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'Base'
d += 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'Derived'
fd += 1;
// no-warning
bp += 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'Base'
dp += 1;
// CHECK-MESSAGES: :[[@LINE-1]]:3: warning: pointer arithmetic on polymorphic object of type 'Derived'
fdp += 1;
// no-warning
}
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