[gobject-introspection] Salvage the build directory parameter of update-glib-annotations.py

[Mikhail Zabaluev <mzabaluev src gnome org>]

commit 0f912a4cc489ff3e6d9ac5c47b46b618fba7400b
Author: Mikhail Zabaluev <mikhail zabaluev gmail com>
Date:   Thu Oct 15 15:41:52 2015 +0300

    Salvage the build directory parameter of update-glib-annotations.py
    
    It was not possible to use the tool with a custom build directory,
    even when it was given as the second command line parameter.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=756665

 misc/update-glib-annotations.py |   17 ++++++++---------
 1 files changed, 8 insertions(+), 9 deletions(-)
---
diff --git a/misc/update-glib-annotations.py b/misc/update-glib-annotations.py
index e4dc32c..e415ad8 100755
--- a/misc/update-glib-annotations.py
+++ b/misc/update-glib-annotations.py
@@ -20,14 +20,6 @@ for k in ['UNINSTALLED_INTROSPECTION_SRCDIR',
         os.environ[k] = path
 
 possible_builddirs = ['../_build/', '..', '../../build/']
-builddir = None
-for d in possible_builddirs:
-    if os.path.isfile(os.path.join(d, 'g-ir-annotation-tool')):
-        builddir = d
-        break
-assert builddir is not None
-annotation_tool_base_args = [os.path.join(builddir, 'g-ir-annotation-tool'),
-                             '--extract']
 
 
 def directory_includes(dirs, srcdir, builddir):
@@ -55,6 +47,9 @@ def extract_annotations(module, srcdir, builddir, outfile):
         if sourcename.endswith('.c'):
             sources.append(os.path.join(subdir, sourcename))
 
+    annotation_tool_base_args = [
+        os.path.join(builddir, 'g-ir-annotation-tool'), '--extract']
+
     return subprocess.check_call(annotation_tool_base_args +
                                  module['defines'] +
                                  includes +
@@ -67,7 +62,11 @@ if __name__ == '__main__':
     if len(sys.argv) == 3:
         builddir = sys.argv[2]
     else:
-        builddir = srcdir
+        for d in possible_builddirs:
+            if os.path.isfile(os.path.join(d, 'g-ir-annotation-tool')):
+                builddir = d
+                break
+        assert builddir is not None
 
     print("Using source directory: '%s' build directory: '%s'" % (srcdir, builddir))