[gnome-builder] meson: Ensure all build flags are absolute paths

[Patrick Griffis <pgriffis src gnome org>]

commit 182e05c57a3cbf3f3c93505f78c3f6109351772a
Author: Patrick Griffis <tingping tingping se>
Date:   Tue Dec 20 05:05:03 2016 -0500

    meson: Ensure all build flags are absolute paths

 plugins/meson/meson_plugin/__init__.py |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)
---
diff --git a/plugins/meson/meson_plugin/__init__.py b/plugins/meson/meson_plugin/__init__.py
index d9da351..8068ee9 100644
--- a/plugins/meson/meson_plugin/__init__.py
+++ b/plugins/meson/meson_plugin/__init__.py
@@ -167,7 +167,16 @@ class MesonBuilder(Ide.Builder):
 
         def extract_flags(command: str):
             flags = GLib.shell_parse_argv(command)[1] # Raises on failure
-            return [flag for flag in flags if flag.startswith(('-I', '-isystem', '-W', '-D'))]
+            build_dir = self._get_build_dir().get_path()
+            wanted_flags = []
+            for flag in flags:
+                if flag.startswith('-I'):
+                    # All paths are relative to build
+                    abspath = path.normpath(path.join(build_dir, flag[2:]))
+                    wanted_flags.append('-I' + abspath)
+                elif flag.startswith(('-isystem', '-W', '-D')):
+                    wanted_flags.append(flag)
+            return wanted_flags
 
         def build_flags_thread():
             commands_file = path.join(self._get_build_dir().get_path(), 'compile_commands.json')