Factor out pkg-config functionality to a separate module.

Functional changes:

* Consistently check that return code from pkg-config is zero.
* Use shell word splitting rules to process pkg-config output to match
  behaviour obtained by running `cc program.cc $(pkg-config --cflags ...)`.
  Fixes issue #171 .
* Use user preferred encoding to process output from pkg-config on
  Python 3. Python 2 behaviour defaults to using ascii encoding as before.

edit creiter: still ignore pkg-config errors by default for now as we
depend on it when glib is a subproject.

3 files changed, 120 insertions, 0 deletions

diff --git a/tests/scanner/Makefile.am b/tests/scanner/Makefile.am
index 30651ee1..91c4a3ee 100644
--- a/tests/scanner/Makefile.am
+++ b/tests/scanner/Makefile.am
@@ -230,6 +230,7 @@ endif
 
 PYTESTS = \
 	test_shlibs.py \
+	test_pkgconfig.py \
 	test_sourcescanner.py \
 	test_transformer.py \
 	test_xmlwriter.py
diff --git a/tests/scanner/meson.build b/tests/scanner/meson.build
index a2ca035e..ea7e9e5f 100644
--- a/tests/scanner/meson.build
+++ b/tests/scanner/meson.build
@@ -12,6 +12,7 @@ if cc.get_id() != 'msvc'
     'test_sourcescanner.py',
     'test_transformer.py',
     'test_xmlwriter.py',
+    'test_pkgconfig.py',
     ]
 endif
 
diff --git a/tests/scanner/test_pkgconfig.py b/tests/scanner/test_pkgconfig.py
new file mode 100644
index 00000000..cca0bf87
--- /dev/null
+++ b/tests/scanner/test_pkgconfig.py
@@ -0,0 +1,118 @@
+# -*- coding: UTF-8 -*-
+#
+# GObject-Introspection - a framework for introspecting GObject libraries
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the
+# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+#
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+from __future__ import unicode_literals
+
+import contextlib
+import os
+import sys
+import tempfile
+import tempfile
+import textwrap
+import time
+import unittest
+
+from giscanner import pkgconfig
+
+
+@contextlib.contextmanager
+def pkg_config_script(code):
+    """Points PKG_CONFIG environment variable to an executable file with given python code.
+    Common leading whitespace is removed from code for convenience."""
+
+    with tempfile.NamedTemporaryFile(mode='wb', suffix='.py', delete=False) as file:
+        file.write('#!{}\n'.format(sys.executable).encode("utf-8"))
+        file.write(textwrap.dedent(code).encode("utf-8"))
+        os.chmod(file.name, 0o777)
+
+    try:
+        yield [sys.executable, file.name]
+    finally:
+        os.unlink(file.name)
+
+
+class PkgConfigTest(unittest.TestCase):
+
+    def test_non_zero_exit_code(self):
+        """Checks that non-zero exit code from pkg-config results in exception."""
+        s = """
+        import sys
+        sys.exit(1)
+        """
+        with self.assertRaises(pkgconfig.PkgConfigError):
+            with pkg_config_script(s) as command:
+                pkgconfig.cflags(['foo'], command=command, ignore_errors=False)
+
+    def test_cflags(self):
+        """Checks arguments passed to pkg-config when asking for --cflags."""
+        s = """
+        import sys
+        args = sys.argv[1:]
+        assert len(args) == 4
+        assert args[0] == '--cflags'
+        assert args[1] == 'foo-1.0'
+        assert args[2] == 'bar-2.0'
+        assert args[3] == 'baz'
+        """
+        with pkg_config_script(s) as command:
+            pkgconfig.cflags(['foo-1.0', 'bar-2.0', 'baz'], command=command)
+
+    def test_libs(self):
+        """Checks arguments passed to pkg-config when asking for --libs."""
+        s = """
+        import sys
+        args = sys.argv[1:]
+        assert len(args) == 3
+        assert args[0] == '--libs'
+        assert args[1] == 'a'
+        assert args[2] == 'b-42.0'
+        """
+        with pkg_config_script(s) as command:
+            pkgconfig.libs(['a', 'b-42.0'], command=command)
+
+    @unittest.skipIf(
+        sys.version_info < (3, 0) or os.name == "nt",
+        "Python 2 defaults to ascii encoding in text file I/O and nothing is done to change that")
+    def test_non_ascii_output(self):
+        with pkg_config_script("""print("-L'zażółć gęślą jaźń'")""") as command:
+            flags = pkgconfig.cflags(['test-1.0'], command=command)
+            self.assertEqual(flags, ["-Lzażółć gęślą jaźń"])
+
+        with pkg_config_script("""print('-Lé')""") as command:
+            flags = pkgconfig.cflags(['test-1.0'], command=command)
+            self.assertEqual(flags, ['-Lé'])
+
+    def test_shell_word_splitting_rules(self):
+        # Regression test for issue #171.
+        with pkg_config_script("""print('-L"/usr/lib64" -lgit2')""") as command:
+            flags = pkgconfig.cflags(['foo-2.0'], command=command)
+            self.assertEqual(flags, ['-L/usr/lib64', '-lgit2'])
+
+        # Macro define for a C string literal.
+        with pkg_config_script('''print("""-DLOG='"HELLO"'""")''') as command:
+            flags = pkgconfig.cflags(['bar-3.0'], command=command)
+            self.assertEqual(flags, ['-DLOG="HELLO"'])
+
+
+if __name__ == '__main__':
+    unittest.main()