Outsource exceptions to reduce dependency on cmodule

theano/link/c/cmodule.py

@@ -28,6 +28,7 @@ from theano.configdefaults import gcc_version_str, local_bitwidth
 # we will abuse the lockfile mechanism when reading and writing the registry
 from theano.gof import compilelock
 from theano.gof.utils import flatten, hash_from_code
+from theano.link.c.exceptions import MissingGXX
 from theano.utils import output_subprocess_Popen, subprocess_Popen
 
 
@@ -45,14 +46,6 @@ METH_NOARGS = "METH_NOARGS"
 import_time = 0
 
 
-class MissingGXX(Exception):
-    """
-    This error is raised when we try to generate c code,
-    but g++ is not available.
-
-    """
-
-
 def debug_counter(name, every=1):
     """
     Debug counter to know how often we go through some piece of code.

theano/link/c/exceptions.py

+class MissingGXX(Exception):
+    """
+    This error is raised when we try to generate c code,
+    but g++ is not available.
+
+    """

theano/link/c/vm.py

@@ -12,8 +12,11 @@ import time
 import warnings
 from collections import defaultdict
 
-import theano.link.c.cmodule
-from theano import config, link
+from theano import config
+from theano.gof import Constant, Variable
+from theano.link.basic import Container, LocalLinker
+from theano.link.c.exceptions import MissingGXX
+from theano.link.utils import gc_helper, map_storage, raise_with_op
 
 
 logger = logging.getLogger(__name__)
@@ -55,7 +58,7 @@ def calculate_reallocate_info(order, fgraph, storage_map, compute_map_re, depend
                 )
                 ins = node.inputs[idx_v[0]]
             if ins is not None:
-                assert isinstance(ins, theano.Variable)
+                assert isinstance(ins, Variable)
                 origin = view_of.get(ins, ins)
                 view_of[out] = origin
                 viewed_by[origin].append(out)
@@ -96,7 +99,7 @@ def calculate_reallocate_info(order, fgraph, storage_map, compute_map_re, depend
                     if (
                         not viewed_by[origin]
                         and origin not in fgraph.inputs
-                        and not isinstance(origin, theano.Constant)
+                        and not isinstance(origin, Constant)
                     ):
                         # where gc
                         for i in range(idx + 1, len(order)):
@@ -255,7 +258,7 @@ class Loop(VM):
                     self.call_counts[i] += 1
                     self.call_times[i] += t1 - t0
             except Exception:
-                link.raise_with_op(self.fgraph, node, thunk)
+                raise_with_op(self.fgraph, node, thunk)
         else:
             for cont in self.pre_call_clear:
                 cont[0] = None
@@ -263,7 +266,7 @@ class Loop(VM):
                 for thunk, node in zip(self.thunks, self.nodes):
                     thunk()
             except Exception:
-                link.raise_with_op(self.fgraph, node, thunk)
+                raise_with_op(self.fgraph, node, thunk)
 
 
 class LoopGC(VM):
@@ -299,7 +302,7 @@ class LoopGC(VM):
                         old_s[0] = None
                     i += 1
             except Exception:
-                link.raise_with_op(self.fgraph, node, thunk)
+                raise_with_op(self.fgraph, node, thunk)
         else:
             for cont in self.pre_call_clear:
                 cont[0] = None
@@ -311,7 +314,7 @@ class LoopGC(VM):
                     for old_s in old_storage:
                         old_s[0] = None
             except Exception:
-                link.raise_with_op(self.fgraph, node, thunk)
+                raise_with_op(self.fgraph, node, thunk)
 
 
 class Stack(VM):
@@ -539,7 +542,7 @@ class Stack(VM):
                                 off = getattr(o[0], "offset", "")
                                 self.variable_offset[var] = off
                     except Exception:
-                        link.raise_with_op(
+                        raise_with_op(
                             self.fgraph,
                             current_apply,
                             self.thunks[self.node_idx[current_apply]],
@@ -611,7 +614,7 @@ class Stack(VM):
                     self.call_times[current_idx] += dt
 
                 except Exception:
-                    link.raise_with_op(
+                    raise_with_op(
                         self.fgraph,
                         current_apply,
                         self.thunks[self.node_idx[current_apply]],
@@ -693,8 +696,8 @@ class Stack(VM):
 try:
     # If cxx is explicitely set to an empty string, we do not want to import neither lazylinker C code
     # nor lazylinker compiled C code from cache.
-    if not theano.config.cxx:
-        raise theano.link.c.cmodule.MissingGXX(
+    if not config.cxx:
+        raise MissingGXX(
             "lazylinker will not be imported if theano.config.cxx is not set."
         )
     from theano.link.c import lazylinker_c
@@ -708,7 +711,7 @@ try:
 
 except ImportError:
     pass
-except (OSError, theano.link.c.cmodule.MissingGXX) as e:
+except (OSError, MissingGXX) as e:
     # OSError happens when g++ is not installed.  In that case, we
     # already changed the default linker to something else then CVM.
     # Currently this is the py linker.
@@ -716,7 +719,7 @@ except (OSError, theano.link.c.cmodule.MissingGXX) as e:
     assert not config._config_var_dict["linker"].default.startswith("cvm"), e
 
 
-class VM_Linker(link.LocalLinker):
+class VM_Linker(LocalLinker):
     """
     Class that satisfies the Linker interface by acting as a VM factory.
 
@@ -774,7 +777,7 @@ class VM_Linker(link.LocalLinker):
         self.callback_input = callback_input
         self.lazy = lazy
         if c_thunks is None:
-            c_thunks = bool(theano.config.cxx)
+            c_thunks = bool(config.cxx)
         self.c_thunks = c_thunks
         self.allow_partial_eval = allow_partial_eval
         self.updated_vars = {}
@@ -1111,7 +1114,7 @@ class VM_Linker(link.LocalLinker):
         fgraph = self.fgraph
         order = self.schedule(fgraph)
 
-        input_storage, output_storage, storage_map = link.map_storage(
+        input_storage, output_storage, storage_map = map_storage(
             fgraph, order, input_storage, output_storage, storage_map
         )
         compute_map = {}
@@ -1185,7 +1188,7 @@ class VM_Linker(link.LocalLinker):
             for pair in reallocated_info.values():
                 storage_map[pair[1]] = storage_map[pair[0]]
 
-        computed, last_user = link.gc_helper(order)
+        computed, last_user = gc_helper(order)
         if self.allow_gc:
             post_thunk_clear = []
             for node in order:
@@ -1220,11 +1223,11 @@ class VM_Linker(link.LocalLinker):
         return (
             vm,
             [
-                link.Container(input, storage)
+                Container(input, storage)
                 for input, storage in zip(fgraph.inputs, input_storage)
             ],
             [
-                link.Container(output, storage, readonly=True)
+                Container(output, storage, readonly=True)
                 for output, storage in zip(fgraph.outputs, output_storage)
             ],
             thunks,

theano/scan/op.py

@@ -64,6 +64,7 @@ from theano.gof.graph import equal_computations, io_connection_pattern
 from theano.gof.toolbox import NoOutputFromInplace
 from theano.gradient import DisconnectedType, NullType, grad_undefined
 from theano.link.c.cc import CLinker
+from theano.link.c.exceptions import MissingGXX
 from theano.link.utils import raise_with_op
 from theano.scan.utils import Validator, forced_replace, hash_listsDictsTuples, safe_new
 from theano.tensor import TensorType, as_tensor_variable
@@ -974,7 +975,7 @@ class Scan(PureOp):
 
         try:
             if impl == "py":
-                raise theano.link.c.cmodule.MissingGXX
+                raise MissingGXX
             cython_mintaps = np.asarray(self.mintaps, dtype="int32")
             cython_tap_array_len = np.asarray(
                 [len(x) for x in self.tap_array], dtype="int32"
@@ -1051,7 +1052,7 @@ class Scan(PureOp):
                     node,
                 )
 
-        except (ImportError, theano.link.c.cmodule.MissingGXX):
+        except (ImportError, MissingGXX):
             p = self.execute
         # default arguments are stored in the closure of `rval`