1 files changed, 121 insertions, 0 deletions
diff --git a/cffi/pkgconfig.py b/cffi/pkgconfig.py
new file mode 100644
index 0000000..5c93f15
--- /dev/null
+++ b/cffi/pkgconfig.py
@@ -0,0 +1,121 @@
+# pkg-config, https://www.freedesktop.org/wiki/Software/pkg-config/ integration for cffi
+import sys, os, subprocess
+
+from .error import PkgConfigError
+
+
+def merge_flags(cfg1, cfg2):
+    """Merge values from cffi config flags cfg2 to cf1
+
+    Example:
+        merge_flags({"libraries": ["one"]}, {"libraries": ["two"]})
+        {"libraries": ["one", "two"]}
+    """
+    for key, value in cfg2.items():
+        if key not in cfg1:
+            cfg1[key] = value
+        else:
+            if not isinstance(cfg1[key], list):
+                raise TypeError("cfg1[%r] should be a list of strings" % (key,))
+            if not isinstance(value, list):
+                raise TypeError("cfg2[%r] should be a list of strings" % (key,))
+            cfg1[key].extend(value)
+    return cfg1
+
+
+def call(libname, flag, encoding=sys.getfilesystemencoding()):
+    """Calls pkg-config and returns the output if found
+    """
+    a = ["pkg-config", "--print-errors"]
+    a.append(flag)
+    a.append(libname)
+    try:
+        pc = subprocess.Popen(a, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    except EnvironmentError as e:
+        raise PkgConfigError("cannot run pkg-config: %s" % (str(e).strip(),))
+
+    bout, berr = pc.communicate()
+    if pc.returncode != 0:
+        try:
+            berr = berr.decode(encoding)
+        except Exception:
+            pass
+        raise PkgConfigError(berr.strip())
+
+    if sys.version_info >= (3,) and not isinstance(bout, str):   # Python 3.x
+        try:
+            bout = bout.decode(encoding)
+        except UnicodeDecodeError:
+            raise PkgConfigError("pkg-config %s %s returned bytes that cannot "
+                                 "be decoded with encoding %r:\n%r" %
+                                 (flag, libname, encoding, bout))
+
+    if os.altsep != '\\' and '\\' in bout:
+        raise PkgConfigError("pkg-config %s %s returned an unsupported "
+                             "backslash-escaped output:\n%r" %
+                             (flag, libname, bout))
+    return bout
+
+
+def flags_from_pkgconfig(libs):
+    r"""Return compiler line flags for FFI.set_source based on pkg-config output
+
+    Usage
+        ...
+        ffibuilder.set_source("_foo", pkgconfig = ["libfoo", "libbar >= 1.8.3"])
+
+    If pkg-config is installed on build machine, then arguments include_dirs,
+    library_dirs, libraries, define_macros, extra_compile_args and
+    extra_link_args are extended with an output of pkg-config for libfoo and
+    libbar.
+
+    Raises PkgConfigError in case the pkg-config call fails.
+    """
+
+    def get_include_dirs(string):
+        return [x[2:] for x in string.split() if x.startswith("-I")]
+
+    def get_library_dirs(string):
+        return [x[2:] for x in string.split() if x.startswith("-L")]
+
+    def get_libraries(string):
+        return [x[2:] for x in string.split() if x.startswith("-l")]
+
+    # convert -Dfoo=bar to list of tuples [("foo", "bar")] expected by distutils
+    def get_macros(string):
+        def _macro(x):
+            x = x[2:]    # drop "-D"
+            if '=' in x:
+                return tuple(x.split("=", 1))  # "-Dfoo=bar" => ("foo", "bar")
+            else:
+                return (x, None)               # "-Dfoo" => ("foo", None)
+        return [_macro(x) for x in string.split() if x.startswith("-D")]
+
+    def get_other_cflags(string):
+        return [x for x in string.split() if not x.startswith("-I") and
+                                             not x.startswith("-D")]
+
+    def get_other_libs(string):
+        return [x for x in string.split() if not x.startswith("-L") and
+                                             not x.startswith("-l")]
+
+    # return kwargs for given libname
+    def kwargs(libname):
+        fse = sys.getfilesystemencoding()
+        all_cflags = call(libname, "--cflags")
+        all_libs = call(libname, "--libs")
+        return {
+            "include_dirs": get_include_dirs(all_cflags),
+            "library_dirs": get_library_dirs(all_libs),
+            "libraries": get_libraries(all_libs),
+            "define_macros": get_macros(all_cflags),
+            "extra_compile_args": get_other_cflags(all_cflags),
+            "extra_link_args": get_other_libs(all_libs),
+            }
+
+    # merge all arguments together
+    ret = {}
+    for libname in libs:
+        lib_flags = kwargs(libname)
+        merge_flags(ret, lib_flags)
+    return ret