Index: lldb/packages/Python/lldbsuite/test/lang/cpp/dynamic_cast/ExtBase.h
===================================================================
--- /dev/null
+++ lldb/packages/Python/lldbsuite/test/lang/cpp/dynamic_cast/ExtBase.h
@@ -0,0 +1,3 @@
+class ExtBase {
+  virtual char bar();
+};
Index: lldb/packages/Python/lldbsuite/test/lang/cpp/dynamic_cast/ExtBase.cpp
===================================================================
--- /dev/null
+++ lldb/packages/Python/lldbsuite/test/lang/cpp/dynamic_cast/ExtBase.cpp
@@ -0,0 +1,5 @@
+#include "ExtBase.h"
+
+char ExtBase::bar() {
+  return 'x';
+}
Index: lldb/packages/Python/lldbsuite/test/lang/cpp/dynamic_cast/Makefile
===================================================================
--- /dev/null
+++ lldb/packages/Python/lldbsuite/test/lang/cpp/dynamic_cast/Makefile
@@ -0,0 +1,3 @@
+LEVEL = ../../../make
+CXX_SOURCES := main.cpp ExtBase.cpp
+include $(LEVEL)/Makefile.rules
Index: lldb/packages/Python/lldbsuite/test/lang/cpp/dynamic_cast/TestDynamicCast.py
===================================================================
--- /dev/null
+++ lldb/packages/Python/lldbsuite/test/lang/cpp/dynamic_cast/TestDynamicCast.py
@@ -0,0 +1,3 @@
+from lldbsuite.test import lldbinline
+
+lldbinline.MakeInlineTest(__file__, globals(), [])
Index: lldb/packages/Python/lldbsuite/test/lang/cpp/dynamic_cast/main.cpp
===================================================================
--- /dev/null
+++ lldb/packages/Python/lldbsuite/test/lang/cpp/dynamic_cast/main.cpp
@@ -0,0 +1,51 @@
+class Base {
+public:
+  virtual char foo() {
+    return 'b';
+  }
+};
+
+class Derived : public Base {
+public:
+  char foo() override {
+    return 'd';
+  }
+};
+
+class NonOverrideDerived : public Base {
+};
+
+#include "ExtBase.h"
+
+class ExtDerived : public ExtBase {
+public:
+  char bar() override {
+    return 'y';
+  }
+};
+
+int main() {
+  Derived d;
+  NonOverrideDerived d2;
+  Base *b = &d;
+  Base *real_base = new Base();
+  char c = dynamic_cast<Derived *>(b)->foo();
+
+  ExtDerived ext_d;
+  ExtBase *ext_b = &ext_d;
+  ExtBase *ext_real_base = new ExtBase();
+  c = dynamic_cast<ExtDerived *>(ext_b)->bar();
+
+
+  return 0; //% self.expect("expression dynamic_cast<class Derived *>(b) == (Derived*)b", substrs = ["bool", " = true"])
+            //% self.expect("expression dynamic_cast<class Base *>(b) == (Base*)b", substrs = ["bool", " = true"])
+            //% self.expect("expression dynamic_cast<class Derived *>(real_base) == nullptr", substrs = ["bool", " = true"])
+            //% self.expect("expression dynamic_cast<class NonOverrideDerived *>(&d) == nullptr", substrs = ["bool", " = true"])
+            //% self.expect("expression dynamic_cast<class ExtDerived *>(real_base) == nullptr", substrs = ["bool", " = true"])
+            //% self.expect("expression dynamic_cast<class Derived *>(&d2) == nullptr", substrs = ["bool", " = true"])
+            //% self.expect("expression dynamic_cast<class NonOverrideDerived *>(&d2) == (NonOverrideDerived *)&d2", substrs = ["bool", " = true"])
+            //% self.expect("expression dynamic_cast<class Derived *>(&ext_d) == nullptr", substrs = ["bool", " = true"])
+            //% self.expect("expression dynamic_cast<class ExtDerived *>(ext_b) == (class ExtDerived*)ext_b", substrs = ["bool", " = true"])
+            //% self.expect("expression dynamic_cast<class ExtBase *>(ext_real_base) == (class ExtBase*)ext_real_base", substrs = ["bool", " = true"])
+            //% self.expect("expression dynamic_cast<class ExtDerived *>(ext_real_base) == nullptr", substrs = ["bool", " = true"])
+}
Index: lldb/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp
===================================================================
--- lldb/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp
+++ lldb/source/Plugins/ExpressionParser/Clang/IRForTarget.cpp
@@ -10,6 +10,7 @@
 
 #include "ClangExpressionDeclMap.h"
 
+#include "llvm/Demangle/Demangle.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/InstrTypes.h"
@@ -1335,6 +1336,11 @@
       if (!global_variable->hasExternalLinkage())
         return true;
 
+      // Typeinfo can be external.
+      std::string demangled = llvm::demangle(global_variable->getName());
+      if (llvm::StringRef(demangled).startswith("typeinfo for "))
+        return true;
+
       if (log)
         LLDB_LOGF(log, "Found global variable \"%s\" without metadata",
                   global_variable->getName().str().c_str());