Warn about attempts to reinterpret_cast between two types that are
hierarchy-related at a possibly nonzero offset.
Patch by Alexander Zinenko!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177698 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/SemaCXX/warn-reinterpret-base-class.cpp b/test/SemaCXX/warn-reinterpret-base-class.cpp
new file mode 100644
index 0000000..fc7d15c
--- /dev/null
+++ b/test/SemaCXX/warn-reinterpret-base-class.cpp
@@ -0,0 +1,234 @@
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify -Wreinterpret-base-class -Wno-unused-volatile-lvalue %s
+
+// PR 13824
+class A {
+};
+class DA : public A {
+};
+class DDA : public DA {
+};
+class DAo : protected A {
+};
+class DAi : private A {
+};
+
+class DVA : public virtual A {
+};
+class DDVA : public virtual DA {
+};
+class DMA : public virtual A, public virtual DA {
+};
+
+class B;
+
+struct C {
+ // Do not fail on incompletely-defined classes.
+ decltype(reinterpret_cast<C *>(0)) foo;
+ decltype(reinterpret_cast<A *>((C *) 0)) bar;
+ decltype(reinterpret_cast<C *>((A *) 0)) baz;
+};
+
+void reinterpret_not_defined_class(B *b, C *c) {
+ // Should not fail if class has no definition.
+ (void)*reinterpret_cast<C *>(b);
+ (void)*reinterpret_cast<B *>(c);
+
+ (void)reinterpret_cast<C &>(*b);
+ (void)reinterpret_cast<B &>(*c);
+}
+
+void reinterpret_not_updowncast(A *pa, const A *pca, A &a, const A &ca) {
+ (void)*reinterpret_cast<C *>(pa);
+ (void)*reinterpret_cast<const C *>(pa);
+ (void)*reinterpret_cast<volatile C *>(pa);
+ (void)*reinterpret_cast<const volatile C *>(pa);
+
+ (void)*reinterpret_cast<const C *>(pca);
+ (void)*reinterpret_cast<const volatile C *>(pca);
+
+ (void)reinterpret_cast<C &>(a);
+ (void)reinterpret_cast<const C &>(a);
+ (void)reinterpret_cast<volatile C &>(a);
+ (void)reinterpret_cast<const volatile C &>(a);
+
+ (void)reinterpret_cast<const C &>(ca);
+ (void)reinterpret_cast<const volatile C &>(ca);
+}
+
+void reinterpret_pointer_downcast(A *a, const A *ca) {
+ (void)*reinterpret_cast<DA *>(a);
+ (void)*reinterpret_cast<const DA *>(a);
+ (void)*reinterpret_cast<volatile DA *>(a);
+ (void)*reinterpret_cast<const volatile DA *>(a);
+
+ (void)*reinterpret_cast<const DA *>(ca);
+ (void)*reinterpret_cast<const volatile DA *>(ca);
+
+ (void)*reinterpret_cast<DDA *>(a);
+ (void)*reinterpret_cast<DAo *>(a);
+ (void)*reinterpret_cast<DAi *>(a);
+ // expected-warning@+2 {{'reinterpret_cast' to class 'DVA *' from its virtual base 'A *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while downcasting}}
+ (void)*reinterpret_cast<DVA *>(a);
+ // expected-warning@+2 {{'reinterpret_cast' to class 'DDVA *' from its virtual base 'A *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while downcasting}}
+ (void)*reinterpret_cast<DDVA *>(a);
+ // expected-warning@+2 {{'reinterpret_cast' to class 'DMA *' from its virtual base 'A *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while downcasting}}
+ (void)*reinterpret_cast<DMA *>(a);
+}
+
+void reinterpret_reference_downcast(A a, A &ra, const A &cra) {
+ (void)reinterpret_cast<DA &>(a);
+ (void)reinterpret_cast<const DA &>(a);
+ (void)reinterpret_cast<volatile DA &>(a);
+ (void)reinterpret_cast<const volatile DA &>(a);
+
+ (void)reinterpret_cast<DA &>(ra);
+ (void)reinterpret_cast<const DA &>(ra);
+ (void)reinterpret_cast<volatile DA &>(ra);
+ (void)reinterpret_cast<const volatile DA &>(ra);
+
+ (void)reinterpret_cast<const DA &>(cra);
+ (void)reinterpret_cast<const volatile DA &>(cra);
+
+ (void)reinterpret_cast<DDA &>(a);
+ (void)reinterpret_cast<DAo &>(a);
+ (void)reinterpret_cast<DAi &>(a);
+ // expected-warning@+2 {{'reinterpret_cast' to class 'DVA &' from its virtual base 'A' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while downcasting}}
+ (void)reinterpret_cast<DVA &>(a);
+ // expected-warning@+2 {{'reinterpret_cast' to class 'DDVA &' from its virtual base 'A' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while downcasting}}
+ (void)reinterpret_cast<DDVA &>(a);
+ // expected-warning@+2 {{'reinterpret_cast' to class 'DMA &' from its virtual base 'A' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while downcasting}}
+ (void)reinterpret_cast<DMA &>(a);
+}
+
+void reinterpret_pointer_upcast(DA *da, const DA *cda, DDA *dda, DAo *dao,
+ DAi *dai, DVA *dva, DDVA *ddva, DMA *dma) {
+ (void)*reinterpret_cast<A *>(da);
+ (void)*reinterpret_cast<const A *>(da);
+ (void)*reinterpret_cast<volatile A *>(da);
+ (void)*reinterpret_cast<const volatile A *>(da);
+
+ (void)*reinterpret_cast<const A *>(cda);
+ (void)*reinterpret_cast<const volatile A *>(cda);
+
+ (void)*reinterpret_cast<A *>(dda);
+ (void)*reinterpret_cast<DA *>(dda);
+ (void)*reinterpret_cast<A *>(dao);
+ (void)*reinterpret_cast<A *>(dai);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'DVA *' to its virtual base 'A *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)*reinterpret_cast<A *>(dva);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'DDVA *' to its virtual base 'A *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)*reinterpret_cast<A *>(ddva);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'DDVA *' to its virtual base 'DA *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)*reinterpret_cast<DA *>(ddva);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'DMA *' to its virtual base 'A *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)*reinterpret_cast<A *>(dma);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'DMA *' to its virtual base 'DA *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)*reinterpret_cast<DA *>(dma);
+}
+
+void reinterpret_reference_upcast(DA &da, const DA &cda, DDA &dda, DAo &dao,
+ DAi &dai, DVA &dva, DDVA &ddva, DMA &dma) {
+ (void)reinterpret_cast<A &>(da);
+ (void)reinterpret_cast<const A &>(da);
+ (void)reinterpret_cast<volatile A &>(da);
+ (void)reinterpret_cast<const volatile A &>(da);
+
+ (void)reinterpret_cast<const A &>(cda);
+ (void)reinterpret_cast<const volatile A &>(cda);
+
+ (void)reinterpret_cast<A &>(dda);
+ (void)reinterpret_cast<DA &>(dda);
+ (void)reinterpret_cast<A &>(dao);
+ (void)reinterpret_cast<A &>(dai);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'DVA' to its virtual base 'A &' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)reinterpret_cast<A &>(dva);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'DDVA' to its virtual base 'A &' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)reinterpret_cast<A &>(ddva);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'DDVA' to its virtual base 'DA &' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)reinterpret_cast<DA &>(ddva);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'DMA' to its virtual base 'A &' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)reinterpret_cast<A &>(dma);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'DMA' to its virtual base 'DA &' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)reinterpret_cast<DA &>(dma);
+}
+
+struct E {
+ int x;
+};
+
+class F : public E {
+ virtual int foo() { return x; }
+};
+
+class G : public F {
+};
+
+class H : public E, public A {
+};
+
+class I : virtual public F {
+};
+
+typedef const F * K;
+typedef volatile K L;
+
+void different_subobject_downcast(E *e, F *f, A *a) {
+ // expected-warning@+2 {{'reinterpret_cast' to class 'F *' from its base at non-zero offset 'E *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while downcasting}}
+ (void)reinterpret_cast<F *>(e);
+ // expected-warning@+2 {{'reinterpret_cast' to class 'G *' from its base at non-zero offset 'E *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while downcasting}}
+ (void)reinterpret_cast<G *>(e);
+ (void)reinterpret_cast<H *>(e);
+ // expected-warning@+2 {{'reinterpret_cast' to class 'I *' from its virtual base 'E *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while downcasting}}
+ (void)reinterpret_cast<I *>(e);
+
+ (void)reinterpret_cast<G *>(f);
+ // expected-warning@+2 {{'reinterpret_cast' to class 'I *' from its virtual base 'F *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while downcasting}}
+ (void)reinterpret_cast<I *>(f);
+
+ (void)reinterpret_cast<H *>(a);
+
+ // expected-warning@+2 {{'reinterpret_cast' to class 'L' (aka 'const F *volatile') from its base at non-zero offset 'E *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while downcasting}}
+ (void)reinterpret_cast<L>(e);
+}
+
+void different_subobject_upcast(F *f, G *g, H *h, I *i) {
+ // expected-warning@+2 {{'reinterpret_cast' from class 'F *' to its base at non-zero offset 'E *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)reinterpret_cast<E *>(f);
+
+ (void)reinterpret_cast<F *>(g);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'G *' to its base at non-zero offset 'E *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)reinterpret_cast<E *>(g);
+
+ (void)reinterpret_cast<E *>(h);
+ (void)reinterpret_cast<A *>(h);
+
+ // expected-warning@+2 {{'reinterpret_cast' from class 'I *' to its virtual base 'F *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)reinterpret_cast<F *>(i);
+ // expected-warning@+2 {{'reinterpret_cast' from class 'I *' to its virtual base 'E *' behaves differently from 'static_cast'}}
+ // expected-note@+1 {{use 'static_cast' to adjust the pointer correctly while upcasting}}
+ (void)reinterpret_cast<E *>(i);
+}