diff --git a/modules/calib3d/perf/perf_precomp.hpp b/modules/calib3d/perf/perf_precomp.hpp
index b13bd664c8..85058e8eef 100644
--- a/modules/calib3d/perf/perf_precomp.hpp
+++ b/modules/calib3d/perf/perf_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_PERF_PRECOMP_HPP__
diff --git a/modules/calib3d/test/test_precomp.hpp b/modules/calib3d/test/test_precomp.hpp
index a95fc1cdc5..0984fe4b41 100644
--- a/modules/calib3d/test/test_precomp.hpp
+++ b/modules/calib3d/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/contrib/test/test_precomp.hpp b/modules/contrib/test/test_precomp.hpp
index 03e1cfe29d..eca300da49 100644
--- a/modules/contrib/test/test_precomp.hpp
+++ b/modules/contrib/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/core/perf/perf_precomp.hpp b/modules/core/perf/perf_precomp.hpp
index 184e84bc40..213de58b29 100644
--- a/modules/core/perf/perf_precomp.hpp
+++ b/modules/core/perf/perf_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_PERF_PRECOMP_HPP__
diff --git a/modules/core/test/test_precomp.hpp b/modules/core/test/test_precomp.hpp
index 1326195a51..9560b6b234 100644
--- a/modules/core/test/test_precomp.hpp
+++ b/modules/core/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/features2d/perf/perf_precomp.hpp b/modules/features2d/perf/perf_precomp.hpp
index 286852b546..b4e7a6209e 100644
--- a/modules/features2d/perf/perf_precomp.hpp
+++ b/modules/features2d/perf/perf_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_PERF_PRECOMP_HPP__
diff --git a/modules/features2d/test/test_precomp.hpp b/modules/features2d/test/test_precomp.hpp
index e2daba111e..6887a477a0 100644
--- a/modules/features2d/test/test_precomp.hpp
+++ b/modules/features2d/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/gpu/perf/perf_precomp.hpp b/modules/gpu/perf/perf_precomp.hpp
index ab35148f24..3a3cb5eecc 100644
--- a/modules/gpu/perf/perf_precomp.hpp
+++ b/modules/gpu/perf/perf_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_PERF_PRECOMP_HPP__
diff --git a/modules/gpu/test/test_precomp.hpp b/modules/gpu/test/test_precomp.hpp
index 46701f52cf..6ef0b33ae5 100644
--- a/modules/gpu/test/test_precomp.hpp
+++ b/modules/gpu/test/test_precomp.hpp
@@ -41,7 +41,10 @@
 
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/highgui/perf/perf_precomp.hpp b/modules/highgui/perf/perf_precomp.hpp
index f7fb98da1b..ec7eb8ca42 100644
--- a/modules/highgui/perf/perf_precomp.hpp
+++ b/modules/highgui/perf/perf_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_PERF_PRECOMP_HPP__
diff --git a/modules/highgui/test/test_precomp.hpp b/modules/highgui/test/test_precomp.hpp
index 5c2c0f004a..10f88c08cf 100644
--- a/modules/highgui/test/test_precomp.hpp
+++ b/modules/highgui/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/imgproc/perf/perf_precomp.hpp b/modules/imgproc/perf/perf_precomp.hpp
index 57e630051e..a9135b2e0a 100644
--- a/modules/imgproc/perf/perf_precomp.hpp
+++ b/modules/imgproc/perf/perf_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_PERF_PRECOMP_HPP__
diff --git a/modules/imgproc/perf/perf_warp.cpp b/modules/imgproc/perf/perf_warp.cpp
index a79768e762..18e441f6dc 100644
--- a/modules/imgproc/perf/perf_warp.cpp
+++ b/modules/imgproc/perf/perf_warp.cpp
@@ -119,7 +119,7 @@ PERF_TEST_P( TestWarpPerspectiveNear_t, WarpPerspectiveNear,
 
     resize(src, src, size);
 
-    int shift = src.cols*0.04;
+    int shift = static_cast<int>(src.cols*0.04);
     Mat srcVertices = (Mat_<Vec2f>(1, 4) << Vec2f(0, 0),
                                             Vec2f(static_cast<float>(size.width-1), 0),
                                             Vec2f(static_cast<float>(size.width-1), static_cast<float>(size.height-1)),
diff --git a/modules/imgproc/test/test_precomp.hpp b/modules/imgproc/test/test_precomp.hpp
index f83a864550..d412dc9abe 100644
--- a/modules/imgproc/test/test_precomp.hpp
+++ b/modules/imgproc/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/legacy/test/test_precomp.hpp b/modules/legacy/test/test_precomp.hpp
index dd9dd0e7ed..2db92c1e8d 100644
--- a/modules/legacy/test/test_precomp.hpp
+++ b/modules/legacy/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/ml/test/test_precomp.hpp b/modules/ml/test/test_precomp.hpp
index 8cda65f831..4b391b6f6f 100644
--- a/modules/ml/test/test_precomp.hpp
+++ b/modules/ml/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/nonfree/perf/perf_precomp.hpp b/modules/nonfree/perf/perf_precomp.hpp
index 62b601e95f..f4dffe6434 100644
--- a/modules/nonfree/perf/perf_precomp.hpp
+++ b/modules/nonfree/perf/perf_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_PERF_PRECOMP_HPP__
diff --git a/modules/nonfree/test/test_precomp.hpp b/modules/nonfree/test/test_precomp.hpp
index 39ac7ecdeb..ab7ca5abac 100644
--- a/modules/nonfree/test/test_precomp.hpp
+++ b/modules/nonfree/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/objdetect/perf/perf_precomp.hpp b/modules/objdetect/perf/perf_precomp.hpp
index 234cb83a39..1146da042a 100644
--- a/modules/objdetect/perf/perf_precomp.hpp
+++ b/modules/objdetect/perf/perf_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_PERF_PRECOMP_HPP__
diff --git a/modules/objdetect/src/haar.cpp b/modules/objdetect/src/haar.cpp
index 92da4ac25d..96bc7603b6 100644
--- a/modules/objdetect/src/haar.cpp
+++ b/modules/objdetect/src/haar.cpp
@@ -728,8 +728,14 @@ double icvEvalHidHaarClassifierAVX( CvHidHaarClassifier* classifier,
 
         sum = _mm256_add_ps(sum,_mm256_load_ps(tmp));
 
-        __m256 left  = _mm256_set_ps(nodes[7]->left, nodes[6]->left, nodes[5]->left, nodes[4]->left, nodes[3]->left, nodes[2]->left, nodes[1]->left, nodes[0]->left );
-        __m256 right = _mm256_set_ps(nodes[7]->right,nodes[6]->right,nodes[5]->right,nodes[4]->right,nodes[3]->right,nodes[2]->right,nodes[1]->right,nodes[0]->right);
+        __m256 left  = _mm256_set_ps(static_cast<float>(nodes[7]->left), static_cast<float>(nodes[6]->left),
+                                     static_cast<float>(nodes[5]->left), static_cast<float>(nodes[4]->left),
+                                     static_cast<float>(nodes[3]->left), static_cast<float>(nodes[2]->left),
+                                     static_cast<float>(nodes[1]->left), static_cast<float>(nodes[0]->left));
+        __m256 right = _mm256_set_ps(static_cast<float>(nodes[7]->right),static_cast<float>(nodes[6]->right),
+                                     static_cast<float>(nodes[5]->right),static_cast<float>(nodes[4]->right),
+                                     static_cast<float>(nodes[3]->right),static_cast<float>(nodes[2]->right),
+                                     static_cast<float>(nodes[1]->right),static_cast<float>(nodes[0]->right));
 
         _mm256_store_si256((__m256i*)idxV, _mm256_cvttps_epi32(_mm256_blendv_ps(right, left, _mm256_cmp_ps(sum, t, _CMP_LT_OQ))));
 
diff --git a/modules/objdetect/test/test_precomp.hpp b/modules/objdetect/test/test_precomp.hpp
index 041fa24c5f..12d0ba00cf 100644
--- a/modules/objdetect/test/test_precomp.hpp
+++ b/modules/objdetect/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/photo/perf/perf_precomp.hpp b/modules/photo/perf/perf_precomp.hpp
index 49ab24809b..0a172dc8a5 100644
--- a/modules/photo/perf/perf_precomp.hpp
+++ b/modules/photo/perf/perf_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_PERF_PRECOMP_HPP__
diff --git a/modules/photo/test/test_precomp.hpp b/modules/photo/test/test_precomp.hpp
index 4496ac889d..3fbf6fef7f 100644
--- a/modules/photo/test/test_precomp.hpp
+++ b/modules/photo/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/stitching/perf/perf_precomp.hpp b/modules/stitching/perf/perf_precomp.hpp
index dddeb07caa..9e6bd7087b 100644
--- a/modules/stitching/perf/perf_precomp.hpp
+++ b/modules/stitching/perf/perf_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_PERF_PRECOMP_HPP__
diff --git a/modules/stitching/test/test_precomp.hpp b/modules/stitching/test/test_precomp.hpp
index 62dba4037c..8189700c1c 100644
--- a/modules/stitching/test/test_precomp.hpp
+++ b/modules/stitching/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/modules/video/perf/perf_precomp.hpp b/modules/video/perf/perf_precomp.hpp
index 18f4144695..327184946c 100644
--- a/modules/video/perf/perf_precomp.hpp
+++ b/modules/video/perf/perf_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_VIDEO_PRECOMP_HPP__
diff --git a/modules/video/test/test_precomp.hpp b/modules/video/test/test_precomp.hpp
index bef6bf6654..3030767f80 100644
--- a/modules/video/test/test_precomp.hpp
+++ b/modules/video/test/test_precomp.hpp
@@ -1,6 +1,9 @@
 #ifdef __GNUC__
 #  pragma GCC diagnostic ignored "-Wmissing-declarations"
-#  pragma GCC diagnostic ignored "-Wmissing-prototypes" //OSX
+#  ifdef __APPLE__
+#    pragma GCC diagnostic ignored "-Wmissing-prototypes"
+#    pragma GCC diagnostic ignored "-Wextra"
+#  endif
 #endif
 
 #ifndef __OPENCV_TEST_PRECOMP_HPP__
diff --git a/samples/cpp/pca.cpp b/samples/cpp/pca.cpp
index eb891be589..ed23c7622b 100644
--- a/samples/cpp/pca.cpp
+++ b/samples/cpp/pca.cpp
@@ -64,7 +64,7 @@ static void read_imgList(const string& filename, vector<Mat>& images) {
 
 static  Mat formatImagesForPCA(const vector<Mat> &data)
 {
-    Mat dst(data.size(), data[0].rows*data[0].cols, CV_32F);
+    Mat dst(static_cast<int>(data.size()), data[0].rows*data[0].cols, CV_32F);
     for(unsigned int i = 0; i < data.size(); i++)
     {
         Mat image_row = data[i].clone().reshape(1,1);