simply alias DEMANGLE_ABI to LLVM_ABI when building llvm

Author: andrurogerz

llvm/CMakeLists.txt

@@ -1078,10 +1078,9 @@ if (LLVM_BUILD_LLVM_DYLIB OR LLVM_BUILD_SHARED_LIBS OR LLVM_ENABLE_PLUGINS)
   set(LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS ON)
 endif()
 
-# Because LLVM-C and Demangle libraries are built into the LLVM library, for now
-# we export their symbols if LLVM symbols are exported.
+# Because LLVM-C is built into the LLVM library, for now export its symbols
+# whenever LLVM symbols are exported.
 set(LLVM_ENABLE_LLVM_C_EXPORT_ANNOTATIONS ${LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS})
-set(LLVM_ENABLE_DEMANGLE_EXPORT_ANNOTATIONS ${LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS})
 
 set(LLVM_ENABLE_NEW_PASS_MANAGER TRUE CACHE BOOL
   "Enable the new pass manager by default.")

llvm/include/llvm/Demangle/Visibility.h

@@ -16,28 +16,10 @@
 #ifndef LLVM_DEMANGLE_VISIBILITY_H
 #define LLVM_DEMANGLE_VISIBILITY_H
 
-#include "llvm/Config/llvm-config.h"
-#include "llvm/Demangle/DemangleConfig.h"
+#include "llvm/Support/Compiler.h"
 
 /// DEMANGLE_ABI is the export/visibility macro used to mark symbols delcared in
-/// llvm/Demangle as exported when built as a shared library.
-
-#if !defined(LLVM_ABI_GENERATING_ANNOTATIONS)
-#if defined(LLVM_ENABLE_DEMANGLE_EXPORT_ANNOTATIONS) &&                        \
-    !defined(LLVM_BUILD_STATIC)
-#if defined(_WIN32) && !defined(__MINGW32__)
-#if defined(LLVM_EXPORTS)
-#define DEMANGLE_ABI __declspec(dllexport)
-#else
-#define DEMANGLE_ABI __declspec(dllimport)
-#endif
-#elif __has_attribute(visibility)
-#define DEMANGLE_ABI __attribute__((visibility("default")))
-#endif
-#endif
-#if !defined(DEMANGLE_ABI)
-#define DEMANGLE_ABI
-#endif
-#endif
+/// llvm/Demangle as exported when LLVM is built as a shared library.
+#define DEMANGLE_ABI LLVM_ABI
 
 #endif