Fixup auto-get dylib for MacOS

Author: cboulay

build_mex.m

@@ -11,6 +11,12 @@
     else
         error('Neither liblsl64.lib nor lsl.lib found in bin/');
     end
+elseif ismac
+    if exist(fullfile(binarypath, 'liblsl64.dylib'), 'file')
+        libs = {'-llsl64'};
+    elseif exist(fullfile(binarypath, 'liblsl.dylib'), 'file')
+        libs = {'-llsl'};
+    end    
 elseif isunix
 	libs = {'-llsl64','-ldl'};
 else

lsl_get_dll.m

@@ -45,8 +45,9 @@
 
 if ~exist(lsl_fname, 'file')
     if ispc
-        % On Windows, also try simply 'lsl.dll'
         new_sopath = fullfile(binarypath, 'lsl.dll');
+    elseif ismac && exist(fullfile(binarypath, 'liblsl.dylib'), 'file')
+        new_sopath = fullfile(binarypath, 'liblsl.dylib');
     else
         new_sopath = fullfile('/usr/lib/', so_fname);
     end
@@ -83,9 +84,13 @@
         copyfile(fullfile(binarypath, 'liblsl_archive', 'lib', 'lsl.lib'),...
             fullfile(binarypath, 'lsl.lib'));
     elseif ismac
-        untar(fullfile(binarypath, liblsl_url_fname),...
-            fullfile(binarypath, 'liblsl_archive'));
-        error('TODO: copyfile from liblsl_archive to lsl_fname on mac.');
+        % Use system tar because Matlab untar does not preserve symlinks.
+        mkdir(fullfile(binarypath, 'liblsl_archive'));
+        system(['tar -C ' fullfile(binarypath, 'liblsl_archive') ' -xf ' fullfile(binarypath, liblsl_url_fname)]);
+        copyfile(fullfile(binarypath, 'liblsl_archive', 'lib', '*.dylib'), binarypath);
+        dylib_list = dir(fullfile(binarypath, '*.dylib'));
+        [~, lib_ix] = min(cellfun(@length, {dylib_list.name}));
+        lsl_fname = fullfile(dylib_list(lib_ix).folder, dylib_list(lib_ix).name);
     elseif isunix
         error(['Automatic extraction of debian package not yet supported.', ...
             ' Please install manually: ' fullfile(binarypath, liblsl_url_fname)]);

lsl_loadlib.m

@@ -43,10 +43,9 @@
     try
         hlib = lsl_loadlib_(dllpath);
     catch e
-        disp('This error is probably because lsl_loadlib_ mex file is not on the path.');
-        disp('Try running build_mex.m. If that was successful, make sure the liblsl-Matlab/bin folder is added to the path.');
         disp('See https://github.com/labstreaminglayer/liblsl-Matlab/#troubleshooting for further troubleshooting tips');
-        error(['Error loading the liblsl library: ', e.message]);
+        error(['Error loading the liblsl library: ', e.message,...
+            ' Make sure liblsl-Matlab/bin is added to path and try running build_mex.m']);
     end
 
     hlib.on_cleanup = onCleanup(@()lsl_freelib_(hlib));