[vala/staging: 2/2] codewriter: Update timestamps of generated c-files if needed

[Rico Tzschichholz <ricotz src gnome org>]

commit 323af9bf138d0bfed58100d9b0d39b17c75f734c
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Fri Feb 24 22:22:21 2017 +0100

    codewriter: Update timestamps of generated c-files if needed
    
    If a changed source-file produces the same ccode we currently leave
    existing files untouched. Although it is better to update the modification
    timestamp of those to at least meet the one of associated source-file.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=683286

 ccode/valaccodewriter.vala |    8 ++++++++
 vapi/glib-2.0.vapi         |    3 +++
 2 files changed, 11 insertions(+), 0 deletions(-)
---
diff --git a/ccode/valaccodewriter.vala b/ccode/valaccodewriter.vala
index 281ff6e..2e58a41 100644
--- a/ccode/valaccodewriter.vala
+++ b/ccode/valaccodewriter.vala
@@ -138,6 +138,14 @@ public class Vala.CCodeWriter {
                                FileUtils.rename (temp_filename, filename);
                        } else {
                                FileUtils.unlink (temp_filename);
+                               if (source_filename != null) {
+                                       var stats = Stat (source_filename);
+                                       var target_stats = Stat (filename);
+                                       if (stats.st_mtime >= target_stats.st_mtime) {
+                                               UTimBuf timebuf = { stats.st_atime + 1, stats.st_mtime + 1 };
+                                               FileUtils.utime (filename, timebuf);
+                                       }
+                               }
                        }
                }
        }
diff --git a/vapi/glib-2.0.vapi b/vapi/glib-2.0.vapi
index 67b0623..65233d9 100644
--- a/vapi/glib-2.0.vapi
+++ b/vapi/glib-2.0.vapi
@@ -3618,6 +3618,9 @@ namespace GLib {
 
        [CCode (cname = "struct stat", cheader_filename = "sys/stat.h,glib/gstdio.h")]
        public struct Stat {
+               public time_t st_atime;
+               public time_t st_mtime;
+               public time_t st_ctime;
                [CCode (cname = "g_stat", instance_pos = -1)]
                public Stat (string filename);
                [Version (since = "2.6")]