added more robust pkg-config handling in setup.py

setup.py

@@ -19,18 +19,33 @@ def readme():
         return ''
 
 
+# http://code.activestate.com/recipes/502261-python-distutils-pkg-config/
+def pkgconfig(libs, optional=''):
+    flag_map = {
+        'include_dirs': ('--cflags-only-I', 2),
+        'library_dirs': ('--libs-only-L', 2),
+        'libraries': ('--libs-only-l', 2),
+        'extra_compile_args': ('--cflags-only-other', 0),
+        'extra_link_args': ('--libs-only-other', 0),
+    }
+    ext_kwargs = {}
+    for lib in libs:
+        for distutils_kwarg, (pkg_option, trim_offset) in flag_map.items():
+            try:
+                options = subprocess.check_output(
+                    ['pkg-config', optional, pkg_option, lib]).decode().split()
+            except subprocess.CalledProcessError:
+                continue
+            ext_kwargs.setdefault(distutils_kwarg, []).extend(
+                [opt[trim_offset:] for opt in options])
+    return ext_kwargs
+
+
 def setup():
     ext = setuptools.extension.Extension(
         'hyperscan',
         ['src/hyperscanmodule.c'],
-        define_macros=[
-
-        ],
-        libraries=['hs'],
-        extra_compile_args=[
-            subprocess.check_output([
-                'pkg-config', '--cflags', 'libhs']).decode('utf-8'),
-        ],
+        **pkgconfig(['libhs'])
     )
     setup_requirements = ['six', 'setuptools>=17.1', 'setuptools_scm']
     setuptools.setup(