[NFC][unwind] Improve error message when a type has more than one RTTIs

The "dynamic_cast error 2" error can apparently happen when the same
type (with RTTI) is defined in more than one translation unit, and
those translation units are linked together. This is technically an
ODR violation, but making the error message more obvious is still
helpful.

llvm-svn: 344052

1 files changed, 3 insertions, 2 deletions

diff --git a/libcxxabi/src/private_typeinfo.cpp b/libcxxabi/src/private_typeinfo.cpp
index 67a5a62dc80..30340a173cf 100644
--- a/libcxxabi/src/private_typeinfo.cpp
+++ b/libcxxabi/src/private_typeinfo.cpp
@@ -651,7 +651,7 @@ __dynamic_cast(const void *static_ptr, const __class_type_info *static_type,
             // We get here only if there is some kind of visibility problem
             //   in client code.
             syslog(LOG_ERR, "dynamic_cast error 1: Both of the following type_info's "
-                    "should have public visibility.  At least one of them is hidden. %s" 
+                    "should have public visibility. At least one of them is hidden. %s"
                     ", %s.\n", static_type->name(), dynamic_type->name());
             // Redo the search comparing type_info's using strcmp
             info = {dst_type, static_ptr, static_type, src2dst_offset, 0};
@@ -674,7 +674,8 @@ __dynamic_cast(const void *static_ptr, const __class_type_info *static_type,
             info.path_dynamic_ptr_to_static_ptr == unknown)
         {
             syslog(LOG_ERR, "dynamic_cast error 2: One or more of the following type_info's "
-                            "has hidden visibility.  They should all have public visibility.  "
+                            "has hidden visibility or is defined in more than one translation "
+                            "unit. They should all have public visibility. "
                             "%s, %s, %s.\n", static_type->name(), dynamic_type->name(),
                     dst_type->name());
             // Redo the search comparing type_info's using strcmp