[crash fix] fix crash in fast compile introduced recently.

theano/gof/__init__.py

@@ -57,7 +57,10 @@ from theano.gof.link import \
 from theano.gof.op import \
     Op, OpenMPOp, PureOp, ops_with_inner_function
 
-from theano.gof.opt import (Optimizer, optimizer, SeqOptimizer,
+from theano.gof.opt import (
+    Optimizer,
+    optimizer, inplace_optimizer,
+    SeqOptimizer,
     MergeOptimizer, MergeOptMerge,
     LocalOptimizer, local_optimizer, LocalOptGroup,
     OpSub, OpRemove, PatternSub,

theano/gof/opt.py

@@ -114,13 +114,13 @@ class Optimizer(object):
 
 class FromFunctionOptimizer(Optimizer):
     """WRITEME"""
-    def __init__(self, fn):
+    def __init__(self, fn, requirements=()):
         self.apply = fn
+        self.requirements = requirements
 
     def add_requirements(self, fgraph):
-        # Added by default
-        #fgraph.attach_feature(toolbox.ReplaceValidate())
-        pass
+        for req in self.requirements:
+            req(fgraph)
 
     def print_summary(self, stream=sys.stdout, level=0, depth=-1):
         print >> stream, "%s%s id=%i" % (
@@ -142,6 +142,16 @@ def optimizer(f):
     return rval
 
 
+def inplace_optimizer(f):
+    """decorator for FromFunctionOptimizer"""
+    dh_handler = dh.DestroyHandler
+    requirements = (lambda fgraph:
+                    fgraph.attach_feature(dh_handler()),)
+    rval = FromFunctionOptimizer(f, requirements)
+    rval.__name__ = f.__name__
+    return rval
+
+
 class SeqOptimizer(Optimizer, list):
     #inherit from Optimizer first to get Optimizer.__hash__
     """WRITEME

theano/tensor/opt.py

@@ -174,7 +174,7 @@ def inplace_elemwise_optimizer_op(OP):
     """
     We parametrise it to make it work for Elemwise and GpuElemwise op.
     """
-    @gof.optimizer
+    @gof.inplace_optimizer
     def inplace_elemwise_optimizer(fgraph):
         """
         Usage: inplace_elemwise_optimizer.optimize(fgraph)