[llvm] simplify export annotation control

Author: andrurogerz

llvm/CMakeLists.txt

@@ -935,6 +935,13 @@ if (LLVM_LINK_LLVM_DYLIB AND BUILD_SHARED_LIBS)
   message(FATAL_ERROR "Cannot enable BUILD_SHARED_LIBS with LLVM_LINK_LLVM_DYLIB.  We recommend disabling BUILD_SHARED_LIBS.")
 endif()
 
+set(LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS OFF)
+if (LLVM_BUILD_LLVM_DYLIB OR LLVM_BUILD_SHARED_LIBS OR LLVM_ENABLE_PLUGINS)
+  # Export annotations for LLVM must be enabled if building as a shared lib or
+  # enabling plugins.
+  set(LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS ON)
+endif()
+
 option(LLVM_OPTIMIZED_TABLEGEN "Force TableGen to be built with optimization" OFF)
 if(CMAKE_CROSSCOMPILING OR (LLVM_OPTIMIZED_TABLEGEN AND (LLVM_ENABLE_ASSERTIONS OR CMAKE_CONFIGURATION_TYPES)))
   set(LLVM_USE_HOST_TOOLS ON)

llvm/include/llvm/Config/llvm-config.h.cmake

@@ -110,6 +110,9 @@
 /* Define if building LLVM with BUILD_SHARED_LIBS */
 #cmakedefine LLVM_BUILD_SHARED_LIBS
 
+/* Define if exporting LLVM public interface for shared library */
+#cmakedefine LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS
+
 /* Define if building LLVM with LLVM_FORCE_USE_OLD_TOOLCHAIN_LIBS */
 #cmakedefine LLVM_FORCE_USE_OLD_TOOLCHAIN ${LLVM_FORCE_USE_OLD_TOOLCHAIN}
 

llvm/include/llvm/Support/Compiler.h

@@ -184,19 +184,8 @@
 // Marker to add to classes or functions in public headers that should not have
 // export macros added to them by the clang tool
 #define LLVM_ABI_NOT_EXPORTED
-#if defined(LLVM_BUILD_LLVM_DYLIB) || defined(LLVM_BUILD_SHARED_LIBS) ||       \
-    defined(LLVM_ENABLE_PLUGINS)
-// Some libraries like those for tablegen are linked in to tools that used
-// in the build so can't depend on the llvm shared library. If export macros
-// were left enabled when building these we would get duplicate or
-// missing symbol linker errors on windows.
-#if defined(LLVM_BUILD_STATIC)
-#define LLVM_ABI
-#define LLVM_ABI_FRIEND
-#define LLVM_TEMPLATE_ABI
-#define LLVM_EXPORT_TEMPLATE
-#define LLVM_ABI_EXPORT
-#elif defined(_WIN32) && !defined(__MINGW32__)
+#if defined(LLVM_ENABLE_LLVM_EXPORT_ANNOTATIONS) && !defined(LLVM_BUILD_STATIC)
+#if defined(_WIN32) && !defined(__MINGW32__)
 #if defined(LLVM_EXPORTS)
 #define LLVM_ABI __declspec(dllexport)
 #define LLVM_TEMPLATE_ABI
@@ -222,7 +211,8 @@
 #define LLVM_EXPORT_TEMPLATE
 #define LLVM_ABI_EXPORT LLVM_ATTRIBUTE_VISIBILITY_DEFAULT
 #endif
-#else
+#endif
+#if !defined(LLVM_ABI)
 #define LLVM_ABI
 #define LLVM_ABI_FRIEND
 #define LLVM_TEMPLATE_ABI