[gnome-builder] build-system: use project cache dir for builds

[Christian Hergert <chergert src gnome org>]

commit 7b8a943a1138ec205ee99756b80a054cfc50c001
Author: Christian Hergert <chergert redhat com>
Date:   Mon Nov 20 23:47:10 2017 -0800

    build-system: use project cache dir for builds
    
    This ensures that we keep the builds in a per-project private
    directory. This is useful so that we can more easily reap
    the project files.

 src/libide/buildsystem/ide-build-system.c |   12 +-----------
 1 files changed, 1 insertions(+), 11 deletions(-)
---
diff --git a/src/libide/buildsystem/ide-build-system.c b/src/libide/buildsystem/ide-build-system.c
index 839da88..0a4c886 100644
--- a/src/libide/buildsystem/ide-build-system.c
+++ b/src/libide/buildsystem/ide-build-system.c
@@ -513,29 +513,19 @@ ide_build_system_get_builddir (IdeBuildSystem   *self,
   if (ret == NULL)
     {
       g_autofree gchar *name = NULL;
-      const gchar *project_id;
       const gchar *config_id;
       const gchar *device_id;
       const gchar *runtime_id;
       IdeContext *context;
-      IdeProject *project;
 
       context = ide_object_get_context (IDE_OBJECT (self));
-      project = ide_context_get_project (context);
-      project_id = ide_project_get_id (project);
       config_id = ide_configuration_get_id (configuration);
       device_id = ide_configuration_get_device_id (configuration);
       runtime_id = ide_configuration_get_runtime_id (configuration);
 
       name = g_strdelimit (g_strdup_printf ("%s-%s-%s", config_id, device_id, runtime_id),
                            "@:/", '-');
-
-      ret = g_build_filename (g_get_user_cache_dir (),
-                              "gnome-builder",
-                              "builds",
-                              project_id,
-                              name,
-                              NULL);
+      ret = ide_context_cache_filename (context, "builds", name, NULL);
     }
 
   IDE_RETURN (ret);