[libcxxabi] Fix multi-level pointer conversions and pointer to member conversion detection.

Summary:
Currently there are bugs in out detection of multi-level pointer conversions and pointer to member conversions. This patch fixes the following issues.

* Allow multi-level pointers with different nested qualifiers.
* Allow multi-level mixed pointers to objects and pointers to members with different nested qualifiers.
* Allow conversions from `int Base::*` to `int Derived::*` but only for non-nested pointers.

There is still some work that needs to be done to clean this patch up but I want to get some input on it.
Open questions:

* Does `__pointer_to_member_type_info::can_catch(...)` need to adjust the pointer if a base to derived conversion is performed?


Reviewers: danalbert, compnerd, mclow.lists

Reviewed By: mclow.lists

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D8758

git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@233984 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 119 insertions, 0 deletions

diff --git a/test/catch_member_data_pointer_01.pass.cpp b/test/catch_member_data_pointer_01.pass.cpp
index 44ff753..298a1c0 100644
--- a/test/catch_member_data_pointer_01.pass.cpp
+++ b/test/catch_member_data_pointer_01.pass.cpp
@@ -18,6 +18,15 @@ struct A
 typedef const int A::*md1;
 typedef       int A::*md2;
 
+struct B : public A
+{
+    const int k;
+    int l;
+};
+
+typedef const int B::*der1;
+typedef       int B::*der2;
+
 void test1()
 {
     try
@@ -34,19 +43,126 @@ void test1()
     }
 }
 
+// Check that cv qualified conversions are allowed.
 void test2()
 {
     try
     {
         throw &A::j;
+    }
+    catch (md2)
+    {
+    }
+    catch (...)
+    {
+        assert(false);
+    }
+
+    try
+    {
+        throw &A::j;
         assert(false);
     }
     catch (md1)
     {
+    }
+    catch (...)
+    {
+        assert(false);
+    }
+}
+
+// Check that Base -> Derived conversions are allowed.
+void test3()
+{
+    try
+    {
+        throw &A::i;
         assert(false);
     }
     catch (md2)
     {
+        assert(false);
+    }
+    catch (der2)
+    {
+        assert(false);
+    }
+    catch (der1)
+    {
+    }
+    catch (md1)
+    {
+        assert(false);
+    }
+}
+
+// Check that Base -> Derived conversions are allowed with different cv
+// qualifiers.
+void test4()
+{
+    try
+    {
+        throw &A::j;
+        assert(false);
+    }
+    catch (der2)
+    {
+    }
+    catch (...)
+    {
+        assert(false);
+    }
+
+    try
+    {
+        throw &A::j;
+        assert(false);
+    }
+    catch (der1)
+    {
+    }
+    catch (...)
+    {
+        assert(false);
+    }
+}
+
+// Check that no Derived -> Base conversions are allowed.
+void test5()
+{
+    try
+    {
+        throw &B::k;
+        assert(false);
+    }
+    catch (md1)
+    {
+        assert(false);
+    }
+    catch (md2)
+    {
+        assert(false);
+    }
+    catch (der1)
+    {
+    }
+
+    try
+    {
+        throw &B::l;
+        assert(false);
+    }
+    catch (md1)
+    {
+        assert(false);
+    }
+    catch (md2)
+    {
+        assert(false);
+    }
+    catch (der2)
+    {
     }
 }
 
@@ -54,4 +170,7 @@ int main()
 {
     test1();
     test2();
+    test3();
+    test4();
+    test5();
 }