If a user manually changes a generated file, don't ever overwrite it.

That way the user can modify an auto-generated 'compile' script, for
example, and it'll stay modified.

If they delete the file, we can then generate it for them again.

Also, we have to warn whenever we're doing this, or people might think it's
a bug.

builder.py

@@ -42,6 +42,10 @@ def _try_stat(filename):
             raise
 
 
+def warn_override(name):
+    warn('%s - you modified it; skipping\n' % name)
+
+
 class ImmediateReturn(Exception):
     def __init__(self, rv):
         Exception.__init__(self, "immediate return with exit code %d" % rv)
@@ -69,6 +73,16 @@ class BuildJob:
                 return self._after2(0)
         except ImmediateReturn, e:
             return self._after2(e.rv)
+        newstamp = sf.read_stamp()
+        if (sf.is_generated and
+            not sf.failed_runid and
+            newstamp != state.STAMP_MISSING and 
+            (sf.stamp != newstamp or sf.is_override)):
+                warn_override(_nice(t))
+                sf.set_override()
+                sf.set_checked()
+                sf.save()
+                return self._after2(0)
         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.
@@ -87,7 +101,6 @@ class BuildJob:
         (dofile, basename, ext) = _find_do_file(sf)
         if not dofile:
             if os.path.exists(t):
-                sf.is_generated = False
                 sf.set_static()
                 sf.save()
                 return self._after2(0)

redo-ifchange.py

@@ -7,6 +7,9 @@ from helpers import debug, debug2, err, unlink
 def dirty_deps(f, depth, max_changed):
     if vars.DEBUG >= 1: debug('%s?%s\n' % (depth, f.name))
 
+    if f.failed_runid:
+        debug('%s-- DIRTY (failed last time)\n' % depth)
+        return True
     if f.changed_runid == None:
         debug('%s-- DIRTY (never built)\n' % depth)
         return True
@@ -35,6 +38,8 @@ def dirty_deps(f, depth, max_changed):
                           max_changed = f.changed_runid):
                 debug('%s-- DIRTY (sub)\n' % depth)
                 return True
+    if f.is_override:
+        builder.warn_override(f.name)
     f.set_checked()
     f.save()
     return False

state.py

@@ -6,6 +6,10 @@ import helpers
 SCHEMA_VER=1
 TIMEOUT=60
 
+STAMP_DIR='dir'     # the stamp of a directory; mtime is unhelpful
+STAMP_MISSING='0'   # the stamp of a nonexistent file
+
+
 def _connect(dbfile):
     _db = sqlite3.connect(dbfile, timeout=TIMEOUT)
     _db.execute("pragma synchronous = off")
@@ -57,6 +61,7 @@ def db():
         _db.execute("create table Files "
                     "    (name not null primary key, "
                     "     is_generated int, "
+                    "     is_override int, "
                     "     checked_runid int, "
                     "     changed_runid int, "
                     "     failed_runid int, "
@@ -134,19 +139,19 @@ def relpath(t, base):
 
 class File(object):
     # use this mostly to avoid accidentally assigning to typos
-    __slots__ = ['id', 'name', 'is_generated',
+    __slots__ = ['id', 'name', 'is_generated', 'is_override',
                  'checked_runid', 'changed_runid', 'failed_runid',
                  'stamp', 'csum']
 
     def _init_from_cols(self, cols):
-        (self.id, self.name, self.is_generated,
+        (self.id, self.name, self.is_generated, self.is_override,
          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, '
+        q = ('select rowid, name, is_generated, is_override, '
              '    checked_runid, changed_runid, failed_runid, '
              '    stamp, csum '
              '  from Files ')
@@ -177,11 +182,11 @@ class File(object):
 
     def save(self):
         _write('update Files set '
-               '    is_generated=?, '
+               '    is_generated=?, is_override=?, '
                '    checked_runid=?, changed_runid=?, failed_runid=?, '
                '    stamp=?, csum=? '
                '    where rowid=?',
-               [self.is_generated,
+               [self.is_generated, self.is_override,
                 self.checked_runid, self.changed_runid, self.failed_runid,
                 self.stamp, self.csum,
                 self.id])
@@ -192,13 +197,23 @@ class File(object):
     def set_changed(self):
         debug2('BUILT: %r (%r)\n' % (self.name, self.stamp))
         self.changed_runid = vars.RUNID
+        self.failed_runid = None
+        self.is_override = False
 
     def set_failed(self):
         debug2('FAILED: %r\n' % self.name)
+        self.update_stamp()
         self.failed_runid = vars.RUNID
+        self.is_generated = True
 
     def set_static(self):
         self.update_stamp()
+        self.is_override = False
+        self.is_generated = False
+
+    def set_override(self):
+        self.update_stamp()
+        self.is_override = True
 
     def update_stamp(self):
         newstamp = self.read_stamp()
@@ -218,7 +233,7 @@ class File(object):
 
     def deps(self):
         q = ('select Deps.mode, Deps.source, '
-             '    name, is_generated, '
+             '    name, is_generated, is_override, '
              '    checked_runid, changed_runid, failed_runid, '
              '    stamp, csum '
              '  from Files '
@@ -247,9 +262,9 @@ class File(object):
         try:
             st = os.stat(os.path.join(vars.BASE, self.name))
         except OSError:
-            return '0'  # does not exist
+            return STAMP_MISSING
         if stat.S_ISDIR(st.st_mode):
-            return 'dir'  # the timestamp of a directory is meaningless
+            return STAMP_DIR
         else:
             # a "unique identifier" stamp for a regular file
             return str((st.st_ctime, st.st_mtime, st.st_size, st.st_ino))

t/flush-cache.sh

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