Proper compiler options from pkg-config

setup.py

@@ -1,29 +1,50 @@
 from os import environ
-from setuptools import setup, Extension  # type: ignore
+from setuptools import setup, Extension  # type: ignore[import-untyped]
+
+
+def pkgconfig(package, kw):
+    result = subprocess.run(
+        ["pkg-config", "--cflags", "--libs", package],
+        capture_output=True,
+        text=True,
+    )
+    if result.returncode == 0:
+        mapping = {
+            '-I': 'include_dirs',
+            '-L': 'library_dirs',
+            '-l': 'libraries',
+        }
+        for token in result.stdout.strip().split():
+            option = token[:2]
+            if option in mapping:
+                kw.setdefault(mapping[option], []).append(token[2:])
+    return kw
+
 
 extra_compile_args = ["-std=c99"]
 extra_link_args = []
 
 if environ.get("COVERAGE_BUILD"):
     extra_compile_args.extend(["--coverage", "-g", "-O0"])
     extra_link_args.extend(["--coverage"])
-
+
+extra_kwargs = {'include_dirs': ["src/"]}
+extra_kwargs = pkgconfig('gmp', extra_kwargs)
+
 curvemath = Extension(
     "fastecdsa.curvemath",
-    include_dirs=["src/"],
-    libraries=["gmp"],
     sources=["src/curveMath.c", "src/curve.c", "src/point.c"],
     extra_compile_args=extra_compile_args,
     extra_link_args=extra_link_args,
+    **extra_kwargs,
 )
 
 _ecdsa = Extension(
     "fastecdsa._ecdsa",
-    include_dirs=["src/"],
-    libraries=["gmp"],
     sources=["src/_ecdsa.c", "src/curveMath.c", "src/curve.c", "src/point.c"],
     extra_compile_args=extra_compile_args,
     extra_link_args=extra_link_args,
+    **extra_kwargs,
 )
 
 setup(