build: support building a .so

You can now select to build a shared object at configure time:

  $ ./gyp_uv -Dcomponent=shared_library -Dlibrary=shared_library

And build it with:

  $ make -C out BUILDTYPE=Debug # or BUILDTYPE=Release

Or, if you use ninja:

  $ ninja -C out/Debug

gyp_uv

@@ -72,12 +72,13 @@ if __name__ == '__main__':
     args.append('-Dgcc_version=%d' % (10 * major + minor))
     args.append('-Dclang=%d' % int(is_clang))
 
-  if not any(a.startswith('-Dtarget_arch') for a in args):
+  if not any(a.startswith('-Dtarget_arch=') for a in args):
     args.append('-Dtarget_arch=ia32')
 
-  if not any(a.startswith('-Dlibrary') for a in args):
+  if not any(a.startswith('-Dlibrary=') for a in args):
     args.append('-Dlibrary=static_library')
 
+  if not any(a.startswith('-Dcomponent=') for a in args):
     args.append('-Dcomponent=static_library')
 
   gyp_args = list(args)

include/uv.h

@@ -1639,9 +1639,11 @@ struct uv_signal_s {
 };
 
 /* These functions are no-ops on Windows. */
-int uv_signal_init(uv_loop_t* loop, uv_signal_t* handle);
-int uv_signal_start(uv_signal_t* handle, uv_signal_cb signal_cb, int signum);
-int uv_signal_stop(uv_signal_t* handle);
+UV_EXTERN int uv_signal_init(uv_loop_t* loop, uv_signal_t* handle);
+UV_EXTERN int uv_signal_start(uv_signal_t* handle,
+                              uv_signal_cb signal_cb,
+                              int signum);
+UV_EXTERN int uv_signal_stop(uv_signal_t* handle);
 
 
 /*

uv.gyp

@@ -144,7 +144,12 @@
             'src/unix/udp.c',
           ],
           'include_dirs': [ 'src/unix/ev', ],
-          'libraries': [ '-lm' ]
+          'libraries': [ '-lm' ],
+          'conditions': [
+            ['"<(library)" == "shared_library"', {
+              'cflags': [ '-fPIC' ],
+            }],
+          ],
         }],
         [ 'OS=="mac"', {
           'sources': [ 'src/unix/darwin.c', 'src/unix/fsevents.c' ],