DR330: when determining whether a cast casts away constness, consider

qualifiers from all levels matching a multidimensional array.

For example, this allows casting from
  pointer to       array of            array of   const volatile int
to
  pointer to const pointer to volatile pointer to                int
because the multidimensional array part of the source type corresponds
to a part of the destination type that contains both 'const' and
'volatile'.

Differential Revision: https://reviews.llvm.org/D49457

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@337422 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 22 insertions, 0 deletions

diff --git a/test/CXX/drs/dr3xx.cpp b/test/CXX/drs/dr3xx.cpp
index 04fd258a7c..d723c5b78c 100644
--- a/test/CXX/drs/dr3xx.cpp
+++ b/test/CXX/drs/dr3xx.cpp
@@ -403,6 +403,28 @@ namespace dr330 { // dr330: 7
     (void) reinterpret_cast<T>(q); // expected-error {{casts away qualifiers}}
     (void) reinterpret_cast<Q>(t);
   }
+
+  namespace swift_17882 {
+    typedef const char P[72];
+    typedef int *Q;
+    void f(P &pr, P *pp) {
+      (void) reinterpret_cast<const Q&>(pr);
+      (void) reinterpret_cast<const Q*>(pp);
+    }
+
+    struct X {};
+    typedef const volatile int A[1][2][3];
+    typedef int *const X::*volatile *B1;
+    typedef int *const X::*         *B2;
+    typedef int *X::*      volatile *B3;
+    typedef volatile int *(*const B4)[4];
+    void f(A *a) {
+      (void) reinterpret_cast<B1*>(a);
+      (void) reinterpret_cast<B2*>(a); // expected-error {{casts away qualifiers}}
+      (void) reinterpret_cast<B3*>(a); // expected-error {{casts away qualifiers}}
+      (void) reinterpret_cast<B4*>(a);
+    }
+  }
 }
 
 namespace dr331 { // dr331: yes