From 4a8fd71a2eb5e057766ec7408e2da9d65662bf6e Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.a.alekhin@gmail.com>
Date: Mon, 3 Jun 2019 20:14:52 +0000
Subject: [PATCH 1/2] core: fix visibility handling

---
 modules/core/include/opencv2/core/cvdef.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/modules/core/include/opencv2/core/cvdef.h b/modules/core/include/opencv2/core/cvdef.h
index 9805d96100..c42517f545 100644
--- a/modules/core/include/opencv2/core/cvdef.h
+++ b/modules/core/include/opencv2/core/cvdef.h
@@ -371,10 +371,10 @@ Cv64suf;
 #  define OPENCV_DISABLE_DEPRECATED_COMPATIBILITY
 #endif
 
-#ifdef CVAPI_EXPORTS
-# if (defined _WIN32 || defined WINCE || defined __CYGWIN__)
+#ifndef CV_EXPORTS
+# if (defined _WIN32 || defined WINCE || defined __CYGWIN__) && defined(CVAPI_EXPORTS)
 #   define CV_EXPORTS __declspec(dllexport)
-# elif defined __GNUC__ && __GNUC__ >= 4
+# elif defined __GNUC__ && __GNUC__ >= 4 && (defined(CVAPI_EXPORTS) || defined(__APPLE__))
 #   define CV_EXPORTS __attribute__ ((visibility ("default")))
 # endif
 #endif

From f5ca9d3fe17caffe7324a965b4aeea7f9d940ec2 Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.alekhin@intel.com>
Date: Tue, 4 Jun 2019 17:40:24 +0300
Subject: [PATCH 2/2] python: visibility

---
 modules/python/common.cmake | 1 -
 modules/python/src2/cv2.cpp | 8 ++++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/modules/python/common.cmake b/modules/python/common.cmake
index 830e4cbc45..17503c03f9 100644
--- a/modules/python/common.cmake
+++ b/modules/python/common.cmake
@@ -61,7 +61,6 @@ ocv_update(OPENCV_PYTHON_EXTENSION_BUILD_PATH "${LIBRARY_OUTPUT_PATH}/${MODULE_I
 set_target_properties(${the_module} PROPERTIES
                       LIBRARY_OUTPUT_DIRECTORY  "${OPENCV_PYTHON_EXTENSION_BUILD_PATH}"
                       ARCHIVE_OUTPUT_NAME ${the_module}  # prevent name conflict for python2/3 outputs
-                      DEFINE_SYMBOL CVAPI_EXPORTS
                       PREFIX ""
                       OUTPUT_NAME cv2
                       SUFFIX ${CVPY_SUFFIX})
diff --git a/modules/python/src2/cv2.cpp b/modules/python/src2/cv2.cpp
index fbe2bbca51..4b2801fca9 100644
--- a/modules/python/src2/cv2.cpp
+++ b/modules/python/src2/cv2.cpp
@@ -1769,8 +1769,12 @@ static int to_ok(PyTypeObject *to)
 }
 
 
+#if defined(__GNUC__)
+#pragma GCC visibility push(default)
+#endif
+
 #if PY_MAJOR_VERSION >= 3
-extern "C" CV_EXPORTS PyObject* PyInit_cv2();
+PyMODINIT_FUNC PyInit_cv2();
 static struct PyModuleDef cv2_moduledef =
 {
     PyModuleDef_HEAD_INIT,
@@ -1783,7 +1787,7 @@ static struct PyModuleDef cv2_moduledef =
 
 PyObject* PyInit_cv2()
 #else
-extern "C" CV_EXPORTS void initcv2();
+PyMODINIT_FUNC initcv2();
 
 void initcv2()
 #endif