From 5f9dcd5364993f32e6841ffdfefce1cc87017b22 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Thu, 22 Nov 2018 12:24:38 +0200
Subject: Make backwards modification time check permanent, add another
 experiment

---
 build2/cc/compile-rule.cxx |  8 ++++++--
 build2/cc/link-rule.cxx    | 25 ++-----------------------
 2 files changed, 8 insertions(+), 25 deletions(-)

(limited to 'build2/cc')

diff --git a/build2/cc/compile-rule.cxx b/build2/cc/compile-rule.cxx
index e361e9d..9326193 100644
--- a/build2/cc/compile-rule.cxx
+++ b/build2/cc/compile-rule.cxx
@@ -4249,7 +4249,8 @@ namespace build2
         return *pr.first;
       }
 
-      // Make sure depdb is no older than any of our prerequisites.
+      // Make sure depdb is no older than any of our prerequisites (see md.mt
+      // logic description above for details).
       //
       touch (md.dd, false, verb_never);
 
@@ -4668,11 +4669,14 @@ namespace build2
         rm.cancel ();
       }
 
+      timestamp now (system_clock::now ());
+      depdb::verify (timestamp_unknown, md.dd, tp, now);
+
       // Should we go to the filesystem and get the new mtime? We know the
       // file has been modified, so instead just use the current clock time.
       // It has the advantage of having the subseconds precision.
       //
-      t.mtime (system_clock::now ());
+      t.mtime (now);
       return target_state::changed;
     }
 
diff --git a/build2/cc/link-rule.cxx b/build2/cc/link-rule.cxx
index 2581d6f..47c058d 100644
--- a/build2/cc/link-rule.cxx
+++ b/build2/cc/link-rule.cxx
@@ -2071,12 +2071,7 @@ namespace build2
       if (dd.writing () || dd.mtime > mt)
         scratch = update = true;
 
-#define BUILD2_MTIME_CHECK
-#ifdef BUILD2_MTIME_CHECK
-      timestamp dd_tt (system_clock::now ());
-#endif
-
-      timestamp dd_cl (dd.close ());
+      dd.close ();
 
       // If nothing changed, then we are done.
       //
@@ -2559,23 +2554,7 @@ namespace build2
       }
 
       rm.cancel ();
-
-#ifdef BUILD2_MTIME_CHECK
-      {
-        timestamp tp_mt (file_mtime (tp));
-        timestamp dd_mt (file_mtime (dd.path));
-        timestamp tp_tt (system_clock::now ());
-
-        if (dd_mt > tp_mt)
-          fail << "backwards modification times:\n"
-               << dd_tt    << " window start\n"
-               << dd_cl    << " write mtime\n"
-               << dd.mtime << " close mtime\n"
-               << dd_mt    << " " << dd.path.string () << '\n'
-               << tp_mt    << " " << tp.string () << '\n'
-               << tp_tt    << " window end";
-      }
-#endif
+      dd.verify (tp);
 
       // Should we go to the filesystem and get the new mtime? We know the
       // file has been modified, so instead just use the current clock time.
-- 
cgit v1.1