diff --git a/clang/include/clang/Interpreter/Value.h b/clang/include/clang/Interpreter/Value.h
--- a/clang/include/clang/Interpreter/Value.h
+++ b/clang/include/clang/Interpreter/Value.h
@@ -52,18 +52,24 @@
 class Interpreter;
 class QualType;
 
-#if __has_attribute(visibility) &&                                             \
-    (!(defined(_WIN32) || defined(__CYGWIN__)) ||                              \
-     (defined(__MINGW32__) && defined(__clang__)))
+#if defined(_WIN32)
+// REPL_EXTERNAL_VISIBILITY are symbols that we need to be able to locate
+// at runtime. On Windows, this requires them to be exported from any of the
+// modules loaded at runtime. Marking them as dllexport achieves this; both
+// for DLLs (that normally export symbols as part of their interface) and for
+// EXEs (that normally don't export anything).
+// For a build with libclang-cpp.dll, this doesn't make any difference - the
+// functions would have been exported anyway. But for cases when these are
+// statically linked into an EXE, it makes sure that they're exported.
+#define REPL_EXTERNAL_VISIBILITY __declspec(dllexport)
+#elif __has_attribute(visibility)
 #if defined(LLVM_BUILD_LLVM_DYLIB) || defined(LLVM_BUILD_SHARED_LIBS)
 #define REPL_EXTERNAL_VISIBILITY __attribute__((visibility("default")))
 #else
 #define REPL_EXTERNAL_VISIBILITY
 #endif
 #else
-#if defined(_WIN32)
-#define REPL_EXTERNAL_VISIBILITY __declspec(dllexport)
-#endif
+#define REPL_EXTERNAL_VISIBILITY
 #endif
 
 #define REPL_BUILTIN_TYPES                                                     \
diff --git a/clang/tools/clang-shlib/CMakeLists.txt b/clang/tools/clang-shlib/CMakeLists.txt
--- a/clang/tools/clang-shlib/CMakeLists.txt
+++ b/clang/tools/clang-shlib/CMakeLists.txt
@@ -53,3 +53,11 @@
 if (NOT APPLE AND NOT MINGW)
   target_link_options(clang-cpp PRIVATE LINKER:-Bsymbolic-functions)
 endif()
+if (MINGW OR CYGWIN)
+  # The clang-cpp DLL is supposed to export all symbols (except for ones
+  # that are explicitly hidden). Normally, this is what happens anyway, but
+  # if there are symbols that are marked explicitly as dllexport, we'd only
+  # export them and nothing else. Therefore, add --export-all-symbols to
+  # make sure we export all symbols despite potential dllexports.
+  target_link_options(clang-cpp PRIVATE LINKER:--export-all-symbols)
+endif()