Added a mechanism to specify a common library path within the configu…

…ration.

Prior to this change you could either put the 3rd party
library into the system 'libraries' directory for the arduino software
(typically at /usr/local/share/arduino/libraries) or copy/symlink it
into the [project]/lib directory.

With this change there is a third option for including 3rd party
libraries.  The build command now allows for another library
directory to be provided.  This library directory will be used just
like the prior two.

The option is "--common-library" and it can be used with the build
command or placed within the standard configuration files.

ino/commands/build.py

@@ -43,6 +43,7 @@ def setup_arg_parser(self, parser):
         super(Build, self).setup_arg_parser(parser)
         self.e.add_board_model_arg(parser)
         self.e.add_arduino_dist_arg(parser)
+        self.e.add_common_libs_arg(parser)
         parser.add_argument('-v', '--verbose', default=False, action='store_true',
                             help='Verbose make output')
 
@@ -60,6 +61,11 @@ def discover(self):
                                     ['hardware', 'arduino', 'variants'],
                                     human_name='Arduino variants directory')
 
+        if self.e.common_lib_dir:
+            print 'Using common library directory: ', self.e.common_lib_dir
+        else:
+            print 'No common library directory specified.'
+
         toolset = [
             ('cc', 'avr-gcc'),
             ('cxx', 'avr-g++'),
@@ -169,6 +175,9 @@ def scan_dependencies(self):
         self.e['deps'] = SpaceList()
 
         lib_dirs = [self.e.arduino_core_dir] + list_subdirs(self.e.lib_dir) + list_subdirs(self.e.arduino_libraries_dir)
+        if self.e['common_lib_dir'] != None:
+            lib_dirs += list_subdirs(self.e['common_lib_dir'])
+
         inc_flags = self.recursive_inc_lib_flags(lib_dirs)
 
         # If lib A depends on lib B it have to appear before B in final

ino/environment.py

@@ -57,6 +57,7 @@ class Environment(dict):
     src_dir = 'src'
     lib_dir = 'lib'
     hex_filename = 'firmware.hex'
+    common_lib_dir = None
 
     arduino_dist_dir = None
     arduino_dist_dir_guesses = [
@@ -211,6 +212,9 @@ def add_arduino_dist_arg(self, parser):
         parser.add_argument('-d', '--arduino-dist', metavar='PATH', 
                             help='Path to Arduino distribution, e.g. ~/Downloads/arduino-0022.\nTry to guess if not specified')
 
+    def add_common_libs_arg(self, parser):
+        parser.add_argument('-l', '--common-library', help='Path to common libraries')
+
     def serial_port_patterns(self):
         system = platform.system()
         if system == 'Linux':
@@ -244,6 +248,12 @@ def process_args(self, args):
         if arduino_dist:
             self['arduino_dist_dir'] = arduino_dist
 
+        common_library_dir = getattr(args, 'common_library', None)
+        if common_library_dir:
+            if not os.path.exists(common_library_dir): 
+                raise Abort( 'Common library path does not exist: %s' % common_library_dir );
+            self['common_lib_dir'] = common_library_dir
+
         board_model = getattr(args, 'board_model', None)
         if board_model:
             all_models = self.board_models()