Don't wipe the timestamp when a target fails to redo.

It's really a separate condition.  And since we're not removing the target
*file* in case of error - we update it atomically, and keeping it is better
than losing it - there's no reason to wipe the timestamp in that case
either.

However, we do need to know that the build failed, so that anybody else
(especially in a parallel build) who looks at that target knows that it
died.  So add a separate flag just for that.

builder.py

@@ -42,6 +42,12 @@ def _try_stat(filename):
             raise
 
 
+class ImmediateReturn(Exception):
+    def __init__(self, rv):
+        Exception.__init__(self, "immediate return with exit code %d" % rv)
+        self.rv = rv
+
+
 class BuildJob:
     def __init__(self, t, sf, lock, shouldbuildfunc, donefunc):
         self.t = t  # original target name, not relative to vars.BASE
@@ -57,9 +63,12 @@ class BuildJob:
         t = self.t
         sf = self.sf
         tmpname = self.tmpname
-        if not self.shouldbuildfunc(t):
-            # target doesn't need to be built; skip the whole task
-            return self._after2(0)
+        try:
+            if not self.shouldbuildfunc(t):
+                # target doesn't need to be built; skip the whole task
+                return self._after2(0)
+        except ImmediateReturn, e:
+            return self._after2(e.rv)
         if (os.path.exists(t) and not os.path.exists(t + '/.')
              and not sf.is_generated):
             # an existing source file that was not generated by us.
@@ -174,8 +183,7 @@ class BuildJob:
         else:
             unlink(tmpname)
             sf = self.sf
-            sf.stamp = None
-            sf.set_changed()
+            sf.set_failed()
             sf.save()
         f.close()
         if rv != 0:
@@ -259,7 +267,7 @@ def main(targets, shouldbuildfunc):
             assert(lock.owned)
             if vars.DEBUG_LOCKS:
                 log('%s (...unlocked!)\n' % _nice(t))
-            if state.File(name=t).stamp == None:
+            if state.File(name=t).is_failed():
                 err('%s: failed in another thread\n' % _nice(t))
                 retcode[0] = 2
                 lock.unlock()

redo-ifchange.py

@@ -42,6 +42,8 @@ def dirty_deps(f, depth, max_changed):
 
 def should_build(t):
     f = state.File(name=t)
+    if f.is_failed():
+        raise builder.ImmediateReturn(32)
     return dirty_deps(f, depth = '', max_changed = vars.RUNID)
 
 

state.py

@@ -59,6 +59,7 @@ def db():
                     "     is_generated int, "
                     "     checked_runid int, "
                     "     changed_runid int, "
+                    "     failed_runid int, "
                     "     stamp, "
                     "     csum)")
         _db.execute("create table Deps "
@@ -134,18 +135,19 @@ def relpath(t, base):
 class File(object):
     # use this mostly to avoid accidentally assigning to typos
     __slots__ = ['id', 'name', 'is_generated',
-                 'checked_runid', 'changed_runid',
+                 'checked_runid', 'changed_runid', 'failed_runid',
                  'stamp', 'csum']
 
     def _init_from_cols(self, cols):
         (self.id, self.name, self.is_generated,
-         self.checked_runid, self.changed_runid,
+         self.checked_runid, self.changed_runid, self.failed_runid,
          self.stamp, self.csum) = cols
     
     def __init__(self, id=None, name=None, cols=None):
         if cols:
             return self._init_from_cols(cols)
-        q = ('select rowid, name, is_generated, checked_runid, changed_runid, '
+        q = ('select rowid, name, is_generated, '
+             '    checked_runid, changed_runid, failed_runid, '
              '    stamp, csum '
              '  from Files ')
         if id != None:
@@ -175,11 +177,12 @@ class File(object):
 
     def save(self):
         _write('update Files set '
-               '    is_generated=?, checked_runid=?, changed_runid=?, '
+               '    is_generated=?, '
+               '    checked_runid=?, changed_runid=?, failed_runid=?, '
                '    stamp=?, csum=? '
                '    where rowid=?',
                [self.is_generated,
-                self.checked_runid, self.changed_runid,
+                self.checked_runid, self.changed_runid, self.failed_runid,
                 self.stamp, self.csum,
                 self.id])
 
@@ -190,6 +193,10 @@ class File(object):
         debug2('BUILT: %r (%r)\n' % (self.name, self.stamp))
         self.changed_runid = vars.RUNID
 
+    def set_failed(self):
+        debug2('FAILED: %r\n' % self.name)
+        self.failed_runid = vars.RUNID
+
     def set_static(self):
         self.update_stamp()
 
@@ -200,15 +207,19 @@ class File(object):
             self.stamp = newstamp
             self.set_changed()
 
-    def is_changed(self):
-        return self.changed_runid and self.changed_runid >= vars.RUNID
-
     def is_checked(self):
         return self.checked_runid and self.checked_runid >= vars.RUNID
 
+    def is_changed(self):
+        return self.changed_runid and self.changed_runid >= vars.RUNID
+
+    def is_failed(self):
+        return self.failed_runid and self.failed_runid >= vars.RUNID
+
     def deps(self):
         q = ('select Deps.mode, Deps.source, '
-             '    name, is_generated, checked_runid, changed_runid, '
+             '    name, is_generated, '
+             '    checked_runid, changed_runid, failed_runid, '
              '    stamp, csum '
              '  from Files '
              '    join Deps on Files.rowid = Deps.source '

t/flush-cache.sh

@@ -4,5 +4,6 @@
 	echo ".timeout 5000"
 	echo "pragma synchronous = off;"
 	echo "update Files set checked_runid=null, " \
-	     "       changed_runid=changed_runid-1;"
+	     "       changed_runid=changed_runid-1, " \
+	     "       failed_runid=null;"
 ) | sqlite3  "$REDO_BASE/.redo/db.sqlite3"