[gnome-builder] flatpak: discover build system using flatpak manifest

[Christian Hergert <chergert src gnome org>]

commit 32dd4e93eccedae9fab6a54b874fdd5410f3bbec
Author: Christian Hergert <chergert redhat com>
Date:   Mon Mar 13 18:25:08 2017 -0700

    flatpak: discover build system using flatpak manifest
    
    If we discover the build system from the manifest, we can provide a type
    hint to the build system loader. This allows us to get the right build
    system for flatpak (thus ensuring our configure opts are correct).
    
    https://bugzilla.gnome.org/show_bug.cgi?id=780006

 plugins/flatpak/Makefile.am                        |    2 +
 .../flatpak/gbp-flatpak-build-system-discovery.c   |  197 ++++++++++++++++++++
 .../flatpak/gbp-flatpak-build-system-discovery.h   |   32 ++++
 plugins/flatpak/gbp-flatpak-plugin.c               |    4 +
 4 files changed, 235 insertions(+), 0 deletions(-)
---
diff --git a/plugins/flatpak/Makefile.am b/plugins/flatpak/Makefile.am
index fd097fa..f2f217c 100644
--- a/plugins/flatpak/Makefile.am
+++ b/plugins/flatpak/Makefile.am
@@ -12,6 +12,8 @@ dist_plugin_DATA = flatpak.plugin
 libflatpak_plugin_la_SOURCES =               \
        gbp-flatpak-application-addin.c      \
        gbp-flatpak-application-addin.h      \
+       gbp-flatpak-build-system-discovery.c \
+       gbp-flatpak-build-system-discovery.h \
        gbp-flatpak-clone-widget.c           \
        gbp-flatpak-clone-widget.h           \
        gbp-flatpak-configuration.c          \
diff --git a/plugins/flatpak/gbp-flatpak-build-system-discovery.c 
b/plugins/flatpak/gbp-flatpak-build-system-discovery.c
new file mode 100644
index 0000000..25eea95
--- /dev/null
+++ b/plugins/flatpak/gbp-flatpak-build-system-discovery.c
@@ -0,0 +1,197 @@
+/* gbp-flatpak-build-system-discovery.c
+ *
+ * Copyright (C) 2017 Christian Hergert <chergert redhat com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define G_LOG_DOMAIN "gbp-flatpak-build-system-discovery"
+
+#include <json-glib/json-glib.h>
+
+#include "gbp-flatpak-build-system-discovery.h"
+
+#define DISCOVERY_MAX_DEPTH 3
+
+/*
+ * TODO: It would be nice if this could share more code with GbpFlatpakConfigurationProvider.
+ */
+
+struct _GbpFlatpakBuildSystemDiscovery
+{
+  GObject parent_instance;
+};
+
+static GRegex *filename_regex;
+
+static void
+gbp_flatpak_build_system_discovery_find_manifests (GFile        *directory,
+                                                   GPtrArray    *results,
+                                                   gint          depth,
+                                                   GCancellable *cancellable)
+{
+  g_autoptr(GFileEnumerator) enumerator = NULL;
+  gpointer infoptr;
+
+  g_assert (G_IS_FILE (directory));
+  g_assert (results != NULL);
+  g_assert (depth < DISCOVERY_MAX_DEPTH);
+
+  enumerator = g_file_enumerate_children (directory,
+                                          G_FILE_ATTRIBUTE_STANDARD_NAME","
+                                          G_FILE_ATTRIBUTE_STANDARD_TYPE,
+                                          G_FILE_QUERY_INFO_NONE,
+                                          cancellable,
+                                          NULL);
+
+  while (NULL != (infoptr = g_file_enumerator_next_file (enumerator, cancellable, NULL)))
+    {
+      g_autoptr(GFileInfo) info = infoptr;
+      g_autoptr(GMatchInfo) match_info = NULL;
+      g_autoptr(GFile) file = NULL;
+      g_autofree gchar *path = NULL;
+      GFileType file_type;
+      const gchar *name;
+
+      if (NULL == (name = g_file_info_get_name (info)))
+        continue;
+
+      file_type = g_file_info_get_file_type (info);
+      file = g_file_get_child (directory, name);
+
+      if (file_type == G_FILE_TYPE_DIRECTORY)
+        {
+          /* TODO: Use a global ignored-file filter from libide */
+          if (g_strcmp0 (name, ".flatpak-builder") == 0 || g_strcmp0 (name, ".git") == 0)
+            continue;
+
+          if (depth < DISCOVERY_MAX_DEPTH - 1)
+            gbp_flatpak_build_system_discovery_find_manifests (file, results, depth + 1, cancellable);
+        }
+
+      g_regex_match (filename_regex, name, 0, &match_info);
+      if (!g_match_info_matches (match_info))
+        continue;
+
+      g_ptr_array_add (results, g_steal_pointer (&file));
+    }
+}
+
+static gchar *
+gbp_flatpak_build_system_discovery_discover (IdeBuildSystemDiscovery  *discovery,
+                                             GFile                    *project_file,
+                                             GCancellable             *cancellable,
+                                             gint                     *priority,
+                                             GError                  **error)
+{
+  g_autoptr(GPtrArray) manifests = NULL;
+
+  IDE_ENTRY;
+
+  g_assert (GBP_IS_FLATPAK_BUILD_SYSTEM_DISCOVERY (discovery));
+  g_assert (G_IS_FILE (project_file));
+  g_assert (!cancellable || G_IS_CANCELLABLE (cancellable));
+  g_assert (priority != NULL);
+
+  manifests = g_ptr_array_new_with_free_func (g_object_unref);
+  gbp_flatpak_build_system_discovery_find_manifests (project_file, manifests, 0, cancellable);
+
+  IDE_TRACE_MSG ("We found %u potential manifests", manifests->len);
+
+  for (guint i = 0; i < manifests->len; i++)
+    {
+      GFile *file = g_ptr_array_index (manifests, i);
+      g_autofree gchar *path = NULL;
+      g_autofree gchar *base = NULL;
+      const gchar *buildsystem;
+      const gchar *app_id_str;
+      g_autoptr(JsonParser) parser = NULL;
+      JsonObject *root_object;
+      JsonNode *root_node;
+      JsonNode *app_id;
+      JsonNode *modules_node;
+      JsonArray *modules_array;
+      JsonNode *source_node;
+      JsonObject *source_object;
+      JsonNode *buildsystem_node;
+      guint len;
+
+      if (NULL == (path = g_file_get_path (file)))
+        continue;
+
+      IDE_TRACE_MSG ("Checking potential manifest \"%s\"", path);
+
+      base = g_file_get_basename (file);
+      parser = json_parser_new ();
+
+      if (!json_parser_load_from_file (parser, path, NULL))
+        continue;
+
+      root_node = json_parser_get_root (parser);
+
+      if (NULL != (root_object = json_node_get_object (root_node)) &&
+          NULL != (app_id = json_object_get_member (root_object, "app-id")) &&
+          JSON_NODE_HOLDS_VALUE (app_id) &&
+          NULL != (app_id_str = json_node_get_string (app_id)) &&
+          g_str_has_prefix (base, app_id_str) &&
+          NULL != (modules_node = json_object_get_member (root_object, "modules")) &&
+          JSON_NODE_HOLDS_ARRAY (modules_node) &&
+          NULL != (modules_array = json_node_get_array (modules_node)) &&
+          /* TODO: Discovery matching source element */
+          (len = json_array_get_length (modules_array)) > 0 &&
+          NULL != (source_node = json_array_get_element (modules_array, len - 1)) &&
+          JSON_NODE_HOLDS_OBJECT (source_node) &&
+          NULL != (source_object = json_node_get_object (source_node)) &&
+          json_object_has_member (source_object, "buildsystem") &&
+          NULL != (buildsystem_node = json_object_get_member (source_object, "buildsystem")) &&
+          JSON_NODE_HOLDS_VALUE (buildsystem_node) &&
+          NULL != (buildsystem = json_node_get_string (buildsystem_node)) &&
+          *buildsystem != '\0')
+        {
+          gchar *ret = g_strdup (buildsystem);
+
+          IDE_TRACE_MSG ("Discovered buildsystem of type \"%s\"", ret);
+
+          *priority = 0;
+
+          IDE_RETURN (ret);
+        }
+    }
+
+  IDE_RETURN (NULL);
+}
+
+static void
+build_system_discovery_iface_init (IdeBuildSystemDiscoveryInterface *iface)
+{
+  iface->discover = gbp_flatpak_build_system_discovery_discover;
+}
+
+G_DEFINE_TYPE_WITH_CODE (GbpFlatpakBuildSystemDiscovery,
+                         gbp_flatpak_build_system_discovery,
+                         G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (IDE_TYPE_BUILD_SYSTEM_DISCOVERY, 
build_system_discovery_iface_init))
+
+static void
+gbp_flatpak_build_system_discovery_class_init (GbpFlatpakBuildSystemDiscoveryClass *klass)
+{
+  /* This regex is based on https://wiki.gnome.org/HowDoI/ChooseApplicationID */
+  filename_regex = g_regex_new ("^[[:alnum:]-_]+\\.[[:alnum:]-_]+(\\.[[:alnum:]-_]+)*\\.json$",
+                                G_REGEX_OPTIMIZE, 0, NULL);
+}
+
+static void
+gbp_flatpak_build_system_discovery_init (GbpFlatpakBuildSystemDiscovery *self)
+{
+}
diff --git a/plugins/flatpak/gbp-flatpak-build-system-discovery.h 
b/plugins/flatpak/gbp-flatpak-build-system-discovery.h
new file mode 100644
index 0000000..8608884
--- /dev/null
+++ b/plugins/flatpak/gbp-flatpak-build-system-discovery.h
@@ -0,0 +1,32 @@
+/* gbp-flatpak-build-system-discovery.h
+ *
+ * Copyright (C) 2017 Christian Hergert <chergert redhat com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GBP_FLATPAK_BUILD_SYSTEM_DISCOVERY_H
+#define GBP_FLATPAK_BUILD_SYSTEM_DISCOVERY_H
+
+#include <ide.h>
+
+G_BEGIN_DECLS
+
+#define GBP_TYPE_FLATPAK_BUILD_SYSTEM_DISCOVERY (gbp_flatpak_build_system_discovery_get_type())
+
+G_DECLARE_FINAL_TYPE (GbpFlatpakBuildSystemDiscovery, gbp_flatpak_build_system_discovery, GBP, 
FLATPAK_BUILD_SYSTEM_DISCOVERY, GObject)
+
+G_END_DECLS
+
+#endif /* GBP_FLATPAK_BUILD_SYSTEM_DISCOVERY_H */
diff --git a/plugins/flatpak/gbp-flatpak-plugin.c b/plugins/flatpak/gbp-flatpak-plugin.c
index 27db656..7ed481a 100644
--- a/plugins/flatpak/gbp-flatpak-plugin.c
+++ b/plugins/flatpak/gbp-flatpak-plugin.c
@@ -20,6 +20,7 @@
 #include <ide.h>
 
 #include "gbp-flatpak-application-addin.h"
+#include "gbp-flatpak-build-system-discovery.h"
 #include "gbp-flatpak-configuration-provider.h"
 #include "gbp-flatpak-genesis-addin.h"
 #include "gbp-flatpak-pipeline-addin.h"
@@ -33,6 +34,9 @@ peas_register_types (PeasObjectModule *module)
   ide_vcs_register_ignored (".flatpak-builder");
 
   peas_object_module_register_extension_type (module,
+                                              IDE_TYPE_BUILD_SYSTEM_DISCOVERY,
+                                              GBP_TYPE_FLATPAK_BUILD_SYSTEM_DISCOVERY);
+  peas_object_module_register_extension_type (module,
                                               IDE_TYPE_CONFIGURATION_PROVIDER,
                                               GBP_TYPE_FLATPAK_CONFIGURATION_PROVIDER);
   peas_object_module_register_extension_type (module,