Add support for referring to host values in embedded functions.

whitequark · whitequark · commit 50448ef554a5 · 2015-08-07T13:24:01.000+03:00
diff --git a/artiq/compiler/embedding.py b/artiq/compiler/embedding.py
@@ -5,7 +5,7 @@
 annotated as ``@kernel`` when they are referenced.
 """
 
-import inspect
+import inspect, os
 from pythonparser import ast, source, diagnostic, parse_buffer
 from . import types, builtins, asttyped, prelude
 from .transforms import ASTTypedRewriter, Inferencer
@@ -28,11 +28,12 @@ def _add(self, fragment):
 
     def quote(self, value):
         """Construct an AST fragment equal to `value`."""
-        if value in (None, True, False):
-            if node.value is True or node.value is False:
-                typ = builtins.TBool()
-            elif node.value is None:
-                typ = builtins.TNone()
+        if value is None:
+            typ = builtins.TNone()
+            return asttyped.NameConstantT(value=value, type=typ,
+                                          loc=self._add(repr(value)))
+        elif value is True or value is False:
+            typ = builtins.TBool()
             return asttyped.NameConstantT(value=value, type=typ,
                                           loc=self._add(repr(value)))
         elif isinstance(value, (int, float)):
@@ -45,12 +46,12 @@ def quote(self, value):
         elif isinstance(value, list):
             begin_loc = self._add("[")
             elts = []
-            for index, elt in value:
+            for index, elt in enumerate(value):
                 elts.append(self.quote(elt))
                 if index < len(value) - 1:
                     self._add(", ")
             end_loc   = self._add("]")
-            return asttyped.ListT(elts=elts, ctx=None, type=types.TVar(),
+            return asttyped.ListT(elts=elts, ctx=None, type=builtins.TList(),
                                   begin_loc=begin_loc, end_loc=end_loc,
                                   loc=begin_loc.join(end_loc))
         else:
@@ -99,7 +100,43 @@ def call(self, function_node, args, kwargs):
             loc=name_loc.join(end_loc))
 
 class StitchingASTTypedRewriter(ASTTypedRewriter):
-    pass
+    def __init__(self, engine, prelude, globals, host_environment, quote_function):
+        super().__init__(engine, prelude)
+        self.globals = globals
+        self.env_stack.append(self.globals)
+
+        self.host_environment = host_environment
+        self.quote_function = quote_function
+
+    def visit_Name(self, node):
+        typ = super()._try_find_name(node.id)
+        if typ is not None:
+            # Value from device environment.
+            return asttyped.NameT(type=typ, id=node.id, ctx=node.ctx,
+                                  loc=node.loc)
+        else:
+            # Try to find this value in the host environment and quote it.
+            if node.id in self.host_environment:
+                value = self.host_environment[node.id]
+                if inspect.isfunction(value):
+                    # It's a function. We need to translate the function and insert
+                    # a reference to it.
+                    function_name = self.quote_function(value)
+                    return asttyped.NameT(id=function_name, ctx=None,
+                                          type=self.globals[function_name],
+                                          loc=node.loc)
+
+                else:
+                    # It's just a value. Quote it.
+                    synthesizer = ASTSynthesizer()
+                    node = synthesizer.quote(value)
+                    synthesizer.finalize()
+                    return node
+            else:
+                diag = diagnostic.Diagnostic("fatal",
+                    "name '{name}' is not bound to anything", {"name":node.id},
+                    node.loc)
+                self.engine.process(diag)
 
 class Stitcher:
     def __init__(self, engine=None):
@@ -108,50 +145,93 @@ def __init__(self, engine=None):
         else:
             self.engine = engine
 
-        self.asttyped_rewriter = StitchingASTTypedRewriter(
-            engine=self.engine, globals=prelude.globals())
-        self.inferencer = Inferencer(engine=self.engine)
+        self.name = ""
+        self.typedtree = []
+        self.prelude = prelude.globals()
+        self.globals = {}
 
-        self.name = "stitched"
-        self.typedtree = None
-        self.globals = self.asttyped_rewriter.globals
+        self.functions = {}
 
         self.rpc_map = {}
 
     def _iterate(self):
+        inferencer = Inferencer(engine=self.engine)
+
         # Iterate inference to fixed point.
         self.inference_finished = False
         while not self.inference_finished:
             self.inference_finished = True
-            self.inferencer.visit(self.typedtree)
+            inferencer.visit(self.typedtree)
+
+        # After we have found all functions, synthesize a module to hold them.
+        self.typedtree = asttyped.ModuleT(
+            typing_env=self.globals, globals_in_scope=set(),
+            body=self.typedtree, loc=None)
 
-    def _parse_embedded_function(self, function):
+    def _quote_embedded_function(self, function):
         if not hasattr(function, "artiq_embedded"):
             raise ValueError("{} is not an embedded function".format(repr(function)))
 
         # Extract function source.
         embedded_function = function.artiq_embedded.function
         source_code = inspect.getsource(embedded_function)
         filename = embedded_function.__code__.co_filename
+        module_name, _ = os.path.splitext(os.path.basename(filename))
         first_line = embedded_function.__code__.co_firstlineno
 
+        # Extract function environment.
+        host_environment = dict()
+        host_environment.update(embedded_function.__globals__)
+        cells = embedded_function.__closure__
+        cell_names = embedded_function.__code__.co_freevars
+        host_environment.update({var: cells[index] for index, var in enumerate(cell_names)})
+
         # Parse.
         source_buffer = source.Buffer(source_code, filename, first_line)
         parsetree, comments = parse_buffer(source_buffer, engine=self.engine)
+        function_node = parsetree.body[0]
 
-        # Rewrite into typed form.
-        typedtree = self.asttyped_rewriter.visit(parsetree)
+        # Mangle the name, since we put everything into a single module.
+        function_node.name = "{}.{}".format(module_name, function_node.name)
+
+        # Normally, LocalExtractor would populate the typing environment
+        # of the module with the function name. However, since we run
+        # ASTTypedRewriter on the function node directly, we need to do it
+        # explicitly.
+        self.globals[function_node.name] = types.TVar()
+
+        # Memoize the function before typing it to handle recursive
+        # invocations.
+        self.functions[function] = function_node.name
 
-        return typedtree, typedtree.body[0]
+        # Rewrite into typed form.
+        asttyped_rewriter = StitchingASTTypedRewriter(
+            engine=self.engine, prelude=self.prelude,
+            globals=self.globals, host_environment=host_environment,
+            quote_function=self._quote_function)
+        return asttyped_rewriter.visit(function_node)
+
+    def _quote_function(self, function):
+        if function in self.functions:
+            return self.functions[function]
+
+        # Insert the typed AST for the new function and restart inference.
+        # It doesn't really matter where we insert as long as it is before
+        # the final call.
+        function_node = self._quote_embedded_function(function)
+        self.typedtree.insert(0, function_node)
+        self.inference_finished = False
+        return function_node.name
 
     def stitch_call(self, function, args, kwargs):
-        self.typedtree, function_node = self._parse_embedded_function(function)
+        function_node = self._quote_embedded_function(function)
+        self.typedtree.append(function_node)
 
-        # We synthesize fake source code for the initial call so that
+        # We synthesize source code for the initial call so that
         # diagnostics would have something meaningful to display to the user.
         synthesizer = ASTSynthesizer()
         call_node = synthesizer.call(function_node, args, kwargs)
         synthesizer.finalize()
-        self.typedtree.body.append(call_node)
+        self.typedtree.append(call_node)
 
         self._iterate()
diff --git a/artiq/compiler/module.py b/artiq/compiler/module.py
@@ -67,7 +67,10 @@ def build_llvm_ir(self, target):
 
     def entry_point(self):
         """Return the name of the function that is the entry point of this module."""
-        return self.name + ".__modinit__"
+        if self.name != "":
+            return self.name + ".__modinit__"
+        else:
+            return "__modinit__"
 
     def __repr__(self):
         printer = types.TypePrinter()
diff --git a/artiq/compiler/transforms/artiq_ir_generator.py b/artiq/compiler/transforms/artiq_ir_generator.py
@@ -70,7 +70,7 @@ class ARTIQIRGenerator(algorithm.Visitor):
     def __init__(self, module_name, engine):
         self.engine = engine
         self.functions = []
-        self.name = [module_name]
+        self.name = [module_name] if module_name != "" else []
         self.current_loc = None
         self.current_function = None
         self.current_globals = set()
diff --git a/artiq/compiler/transforms/asttyped_rewriter.py b/artiq/compiler/transforms/asttyped_rewriter.py
@@ -185,10 +185,10 @@ class ASTTypedRewriter(algorithm.Transformer):
     via :class:`LocalExtractor`.
     """
 
-    def __init__(self, engine, globals):
+    def __init__(self, engine, prelude):
         self.engine = engine
         self.globals = None
-        self.env_stack = [globals]
+        self.env_stack = [prelude]
 
     def _try_find_name(self, name):
         for typing_env in reversed(self.env_stack):
