compiler: allow RPCing builtin functions.

Fixes #366.

artiq/compiler/embedding.py

@@ -5,7 +5,7 @@ the references to the host objects and translates the functions
 annotated as ``@kernel`` when they are referenced.
 """
 
-import sys, os, re, linecache, inspect, textwrap
+import sys, os, re, linecache, inspect, textwrap, types as pytypes
 from collections import OrderedDict, defaultdict
 
 from pythonparser import ast, algorithm, source, diagnostic, parse_buffer
@@ -102,7 +102,8 @@ class ASTSynthesizer:
             return asttyped.ListT(elts=elts, ctx=None, type=builtins.TList(),
                                   begin_loc=begin_loc, end_loc=end_loc,
                                   loc=begin_loc.join(end_loc))
-        elif inspect.isfunction(value) or inspect.ismethod(value):
+        elif inspect.isfunction(value) or inspect.ismethod(value) or \
+                isinstance(value, pytypes.BuiltinFunctionType):
             quote_loc   = self._add('`')
             repr_loc    = self._add(repr(value))
             unquote_loc = self._add('`')
@@ -734,17 +735,21 @@ class Stitcher:
         self.functions[function] = function_type
         return function_type
 
-    def _quote_rpc(self, function, loc):
-        signature = inspect.signature(function)
-
-        if signature.return_annotation is not inspect.Signature.empty:
-            ret_type = self._extract_annot(function, signature.return_annotation,
-                                           "return type", loc, is_syscall=False)
-        else:
+    def _quote_rpc(self, callee, loc):
         ret_type = builtins.TNone()
 
-        function_type = types.TRPC(ret_type, service=self.object_map.store(function))
-        self.functions[function] = function_type
+        if isinstance(callee, pytypes.BuiltinFunctionType):
+            pass
+        elif isinstance(callee, pytypes.FunctionType):
+            signature = inspect.signature(callee)
+            if signature.return_annotation is not inspect.Signature.empty:
+                ret_type = self._extract_annot(callee, signature.return_annotation,
+                                               "return type", loc, is_syscall=False)
+        else:
+            assert False
+
+        function_type = types.TRPC(ret_type, service=self.object_map.store(callee))
+        self.functions[callee] = function_type
         return function_type
 
     def _quote_function(self, function, loc):

artiq/compiler/transforms/llvm_ir_generator.py

@@ -412,7 +412,8 @@ class LLVMIRGenerator:
 
         for obj_id in self.object_map:
             obj_ref = self.object_map.retrieve(obj_id)
-            if isinstance(obj_ref, (pytypes.FunctionType, pytypes.MethodType)):
+            if isinstance(obj_ref, (pytypes.FunctionType, pytypes.MethodType,
+                                    pytypes.BuiltinFunctionType)):
                 continue
             elif isinstance(obj_ref, type):
                 _, typ = self.type_map[obj_ref]

artiq/coredevice/comm_generic.py

@@ -345,7 +345,7 @@ class CommGeneric:
         else:
             raise IOError("Unknown RPC value tag: {}".format(repr(tag)))
 
-    def _receive_rpc_args(self, object_map, defaults):
+    def _receive_rpc_args(self, object_map):
         args, kwargs = [], {}
         while True:
             value = self._receive_rpc_value(object_map)
@@ -443,7 +443,7 @@ class CommGeneric:
         else:
             service = object_map.retrieve(service_id)
 
-        args, kwargs = self._receive_rpc_args(object_map, service.__defaults__)
+        args, kwargs = self._receive_rpc_args(object_map)
         return_tags  = self._read_bytes()
         logger.debug("rpc service: [%d]%r %r %r -> %s", service_id, service, args, kwargs, return_tags)
 

artiq/test/coredevice/test_embedding.py

@@ -1,3 +1,5 @@
+from time import sleep
+
 from artiq.experiment import *
 from artiq.test.hardware_testbench import ExperimentCase
 
@@ -97,6 +99,10 @@ class _RPC(EnvExperiment):
     def args1kwargs2(self):
         return self.kwargs("X", a="A", b=1)
 
+    @kernel
+    def builtin(self):
+        sleep(1.0)
+
 class RPCTest(ExperimentCase):
     def test_args(self):
         exp = self.create(_RPC)
@@ -107,6 +113,7 @@ class RPCTest(ExperimentCase):
         self.assertEqual(exp.kwargs1(), 1)
         self.assertEqual(exp.kwargs2(), 2)
         self.assertEqual(exp.args1kwargs2(), 2)
+        exp.builtin()
 
 
 class _Payload1MB(EnvExperiment):