compiler: Draft operator error handling

devito/exceptions.py

@@ -14,5 +14,9 @@ class InvalidOperator(DevitoError):
     pass
 
 
+class ExecutionError(DevitoError):
+    pass
+
+
 class VisitorException(DevitoError):
     pass

devito/ir/iet/nodes.py

@@ -794,17 +794,19 @@ class CallableBody(MultiTraversable):
         Data unbundling for `body`.
     frees : list of Calls, optional
         Data deallocations for `body`.
+    errors : list of Nodes, optional
+        Error handling for `body`.
     """
 
     is_CallableBody = True
 
     _traversable = ['unpacks', 'init', 'standalones', 'allocs', 'stacks',
                     'casts', 'bundles', 'maps', 'strides', 'objs', 'body',
-                    'unmaps', 'unbundles', 'frees']
+                    'unmaps', 'unbundles', 'frees', 'errors']
 
     def __init__(self, body, init=(), standalones=(), unpacks=(), strides=(),
                  allocs=(), stacks=(), casts=(), bundles=(), objs=(), maps=(),
-                 unmaps=(), unbundles=(), frees=()):
+                 unmaps=(), unbundles=(), frees=(), errors=()):
         # Sanity check
         assert not isinstance(body, CallableBody), "CallableBody's cannot be nested"
 
@@ -823,6 +825,7 @@ def __init__(self, body, init=(), standalones=(), unpacks=(), strides=(),
         self.unmaps = as_tuple(unmaps)
         self.unbundles = as_tuple(unbundles)
         self.frees = as_tuple(frees)
+        self.errors = as_tuple(errors)
 
     def __repr__(self):
         return ("<CallableBody <unpacks=%d, allocs=%d, casts=%d, maps=%d, "

devito/operator/operator.py

@@ -8,7 +8,7 @@
 
 from devito.arch import compiler_registry, platform_registry
 from devito.data import default_allocator
-from devito.exceptions import InvalidOperator
+from devito.exceptions import InvalidOperator, ExecutionError
 from devito.logger import debug, info, perf, warning, is_log_enabled_for
 from devito.ir.equations import LoweredEq, lower_exprs
 from devito.ir.clusters import ClusterGroup, clusterize
@@ -21,7 +21,8 @@
 from devito.mpi import MPI
 from devito.parameters import configuration
 from devito.passes import (Graph, lower_index_derivatives, generate_implicit,
-                           generate_macros, minimize_symbols, unevaluate)
+                           generate_macros, minimize_symbols, unevaluate,
+                           error_mapper)
 from devito.symbolics import estimate_cost
 from devito.tools import (DAG, OrderedSet, Signer, ReducerMap, as_tuple, flatten,
                           filter_sorted, frozendict, is_integer, split, timed_pass,
@@ -647,7 +648,14 @@ def _prepare_arguments(self, autotune=None, **kwargs):
         return args
 
     def _postprocess_errors(self, retval):
-        return
+        if retval == 0:
+            return
+        elif retval == error_mapper['Stability']:
+            raise ExecutionError("Detected nan/inf in some output Functions")
+        elif retval == error_mapper['KernelLaunch']:
+            raise ExecutionError("Kernel launch failed")
+        else:
+            raise ExecutionError("An error occurred during execution")
 
     def _postprocess_arguments(self, args, **kwargs):
         """Process runtime arguments upon returning from ``.apply()``."""

devito/passes/iet/__init__.py

@@ -7,3 +7,4 @@
 from .asynchrony import *  # noqa
 from .instrument import *  # noqa
 from .languages import *  # noqa
+from .errors import *  # noqa

devito/passes/iet/errors.py

@@ -0,0 +1,19 @@
+from devito.passes.iet.engine import iet_pass
+
+__all__ = ['check_stability', 'error_mapper']
+
+
+@iet_pass
+def check_stability(iet, **kwargs):
+    """
+    Check if the simulation is stable. If not, return to Python as quickly as
+    possible with an error code.
+    """
+    # TODO
+    return iet, {}
+
+
+error_mapper = {
+    'Stability': 100,
+    'KernelLaunch': 200,
+}