[gnome-builder] autotools: track buffer changes for makefile invalidation

[Christian Hergert <chergert src gnome org>]

commit 916fa5d806287d52af9d59b0eb380b48a2395fce
Author: Christian Hergert <christian hergert me>
Date:   Thu May 14 19:06:10 2015 -0700

    autotools: track buffer changes for makefile invalidation
    
    Clearly, the right way to do this is to watch all of the Makefile.am and
    included makefiles (often .mk) for changes using inotify/kqueue/etc.
    
    However, that is a lot more work and requires real plumbing. Something we
    want to do, but after we have time to write real makefile parsers.
    Instead, let's just track buffer changes and invalidate the makecache if
    something that resembled a makefile was edited by the user.
    
    We wont catch external modifications, but at least internal ones will
    work for now.

 libide/autotools/ide-autotools-build-system.c |   90 +++++++++++++++++++++++++
 1 files changed, 90 insertions(+), 0 deletions(-)
---
diff --git a/libide/autotools/ide-autotools-build-system.c b/libide/autotools/ide-autotools-build-system.c
index 2a5438f..2fe0019 100644
--- a/libide/autotools/ide-autotools-build-system.c
+++ b/libide/autotools/ide-autotools-build-system.c
@@ -18,11 +18,13 @@
 
 #include <glib/gi18n.h>
 #include <gio/gio.h>
+#include <gtksourceview/gtksource.h>
 
 #include "egg-counter.h"
 
 #include "ide-autotools-build-system.h"
 #include "ide-autotools-builder.h"
+#include "ide-buffer-manager.h"
 #include "ide-context.h"
 #include "ide-device.h"
 #include "ide-device-manager.h"
@@ -519,6 +521,93 @@ ide_autotools_build_system_get_build_flags_finish (IdeBuildSystem  *build_system
 }
 
 static void
+invalidate_makecache (IdeAutotoolsBuildSystem *self)
+{
+  IdeAutotoolsBuildSystemPrivate *priv = ide_autotools_build_system_get_instance_private (self);
+
+  g_assert (IDE_IS_AUTOTOOLS_BUILD_SYSTEM (self));
+
+  g_clear_object (&priv->makecache);
+}
+
+static gboolean
+looks_like_makefile (IdeBuffer *buffer)
+{
+  GtkSourceLanguage *language;
+  const gchar *path;
+  IdeFile *file;
+
+  g_assert (IDE_IS_BUFFER (buffer));
+
+  file = ide_buffer_get_file (buffer);
+  path = ide_file_get_path (file);
+
+  if (path != NULL)
+    {
+      if (g_str_has_suffix (path, "Makefile.am") || g_str_has_suffix (path, ".mk"))
+        return TRUE;
+    }
+
+  language = gtk_source_buffer_get_language (GTK_SOURCE_BUFFER (buffer));
+
+  if (language != NULL)
+    {
+      const gchar *lang_id;
+
+      lang_id = gtk_source_language_get_id (language);
+
+      if (ide_str_equal0 (lang_id, "automake") || ide_str_equal0 (lang_id, "makefile"))
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
+static void
+ide_autotools_build_system__buffer_saved_cb (IdeAutotoolsBuildSystem *self,
+                                             IdeBuffer               *buffer,
+                                             IdeBufferManager        *buffer_manager)
+{
+  g_assert (IDE_IS_AUTOTOOLS_BUILD_SYSTEM (self));
+  g_assert (IDE_IS_BUFFER (buffer));
+  g_assert (IDE_IS_BUFFER_MANAGER (buffer_manager));
+
+  if (looks_like_makefile (buffer))
+    invalidate_makecache (self);
+}
+
+static void
+ide_autotools_build_system_constructed (GObject *object)
+{
+  IdeAutotoolsBuildSystem *self = (IdeAutotoolsBuildSystem *)object;
+  IdeBufferManager *buffer_manager;
+  IdeContext *context;
+
+
+  G_OBJECT_CLASS (ide_autotools_build_system_parent_class)->constructed (object);
+
+  context = ide_object_get_context (IDE_OBJECT (self));
+  buffer_manager = ide_context_get_buffer_manager (context);
+
+  /*
+   * FIXME:
+   *
+   * We could setup and try to track all of the makefiles in the system
+   * with inotify watches. That would require that 1) we can tell if a file
+   * is an automake file (or a dependent included file), and 2) lots of
+   * inotify watches.
+   *
+   * What is cheap, easy, and can be done right now is to just watch for save
+   * events on files that look like makefiles, and invalidate the makecache.
+   */
+  g_signal_connect_object (buffer_manager,
+                           "buffer-saved",
+                           G_CALLBACK (ide_autotools_build_system__buffer_saved_cb),
+                           self,
+                           G_CONNECT_SWAPPED);
+}
+
+static void
 ide_autotools_build_system_finalize (GObject *object)
 {
   IdeAutotoolsBuildSystemPrivate *priv;
@@ -558,6 +647,7 @@ ide_autotools_build_system_class_init (IdeAutotoolsBuildSystemClass *klass)
   GObjectClass *object_class = G_OBJECT_CLASS (klass);
   IdeBuildSystemClass *build_system_class = IDE_BUILD_SYSTEM_CLASS (klass);
 
+  object_class->constructed = ide_autotools_build_system_constructed;
   object_class->finalize = ide_autotools_build_system_finalize;
   object_class->get_property = ide_autotools_build_system_get_property;