add an empty call target for an empty codestring, similar to cpython

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/code/PCode.java

@@ -48,6 +48,7 @@
 
 import com.oracle.graal.python.PythonLanguage;
 import com.oracle.graal.python.builtins.PythonBuiltinClassType;
+import com.oracle.graal.python.builtins.objects.PNone;
 import com.oracle.graal.python.builtins.objects.cell.PCell;
 import com.oracle.graal.python.builtins.objects.common.HashingStorage;
 import com.oracle.graal.python.builtins.objects.dict.PDict;
@@ -75,6 +76,7 @@
 import com.oracle.truffle.api.frame.FrameSlot;
 import com.oracle.truffle.api.frame.FrameSlotKind;
 import com.oracle.truffle.api.frame.MaterializedFrame;
+import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.api.nodes.Node;
 import com.oracle.truffle.api.nodes.NodeUtil;
 import com.oracle.truffle.api.nodes.RootNode;
@@ -158,60 +160,69 @@ public PCode(LazyPythonClass cls, int argcount, int kwonlyargcount,
 
         // Derive a new call target from the code string, if we can
         RootNode rootNode = null;
-        if ((flags & FLAG_MODULE) == 0) {
-            // we're looking for the function, not the module
-            String funcdef;
-            if (freevars.length > 0) {
-                // we build an outer function to provide the initial scoping
-                String outernme = "_____" + System.nanoTime();
-                StringBuilder sb = new StringBuilder();
-                sb.append("def ").append(outernme).append("():\n");
-                for (Object freevar : freevars) {
-                    String v;
-                    if (freevar instanceof PString) {
-                        v = ((PString) freevar).getValue();
-                    } else if (freevar instanceof String) {
-                        v = (String) freevar;
-                    } else {
-                        continue;
+        if (codestring.length > 0) {
+            if ((flags & FLAG_MODULE) == 0) {
+                // we're looking for the function, not the module
+                String funcdef;
+                if (freevars.length > 0) {
+                    // we build an outer function to provide the initial scoping
+                    String outernme = "_____" + System.nanoTime();
+                    StringBuilder sb = new StringBuilder();
+                    sb.append("def ").append(outernme).append("():\n");
+                    for (Object freevar : freevars) {
+                        String v;
+                        if (freevar instanceof PString) {
+                            v = ((PString) freevar).getValue();
+                        } else if (freevar instanceof String) {
+                            v = (String) freevar;
+                        } else {
+                            continue;
+                        }
+                        sb.append(" ").append(v).append(" = None\n");
                     }
-                    sb.append(" ").append(v).append(" = None\n");
+                    sb.append(" global ").append(name).append("\n");
+                    sb.append(" ").append(new String(codestring));
+                    sb.append("\n\n").append(outernme).append("()");
+                    funcdef = sb.toString();
+                } else {
+                    funcdef = new String(codestring);
                 }
-                sb.append(" global ").append(name).append("\n");
-                sb.append(" ").append(new String(codestring));
-                sb.append("\n\n").append(outernme).append("()");
-                funcdef = sb.toString();
-            } else {
-                funcdef = new String(codestring);
-            }
 
-            rootNode = (RootNode) PythonLanguage.getCore().getParser().parse(ParserMode.File, PythonLanguage.getCore(), Source.newBuilder("python", funcdef, name).build(), null);
-            Object[] args = PArguments.create();
-            PDict globals = PythonLanguage.getCore().factory().createDict();
-            PArguments.setGlobals(args, globals);
-            Truffle.getRuntime().createCallTarget(rootNode).call(args);
-            Object function = globals.getDictStorage().getItem(name, HashingStorage.getSlowPathEquivalence(name));
-            if (function instanceof PFunction) {
-                rootNode = ((PFunction) function).getFunctionRootNode();
+                rootNode = (RootNode) PythonLanguage.getCore().getParser().parse(ParserMode.File, PythonLanguage.getCore(), Source.newBuilder("python", funcdef, name).build(), null);
+                Object[] args = PArguments.create();
+                PDict globals = PythonLanguage.getCore().factory().createDict();
+                PArguments.setGlobals(args, globals);
+                Truffle.getRuntime().createCallTarget(rootNode).call(args);
+                Object function = globals.getDictStorage().getItem(name, HashingStorage.getSlowPathEquivalence(name));
+                if (function instanceof PFunction) {
+                    rootNode = ((PFunction) function).getFunctionRootNode();
+                } else {
+                    throw PythonLanguage.getCore().raise(PythonBuiltinClassType.ValueError, "got an invalid codestring trying to create a function code object");
+                }
             } else {
-                throw PythonLanguage.getCore().raise(PythonBuiltinClassType.ValueError, "got an invalid codestring trying to create a function code object");
+                MaterializedFrame frame = null;
+                if (freevars.length > 0) {
+                    FrameDescriptor frameDescriptor = new FrameDescriptor();
+                    frame = Truffle.getRuntime().createMaterializedFrame(new Object[0], frameDescriptor);
+                    for (int i = 0; i < freevars.length; i++) {
+                        Object ident = freevars[i];
+                        FrameSlot slot = frameDescriptor.addFrameSlot(ident);
+                        frameDescriptor.setFrameSlotKind(slot, FrameSlotKind.Object);
+                        frame.setObject(slot, new PCell());
+                    }
+                }
+                rootNode = (RootNode) PythonLanguage.getCore().getParser().parse(ParserMode.File, PythonLanguage.getCore(), Source.newBuilder("python", new String(codestring), name).build(), frame);
+                assert rootNode instanceof ModuleRootNode;
             }
+            this.callTarget = Truffle.getRuntime().createCallTarget(rootNode);
         } else {
-            MaterializedFrame frame = null;
-            if (freevars.length > 0) {
-                FrameDescriptor frameDescriptor = new FrameDescriptor();
-                frame = Truffle.getRuntime().createMaterializedFrame(new Object[0], frameDescriptor);
-                for (int i = 0; i < freevars.length; i++) {
-                    Object ident = freevars[i];
-                    FrameSlot slot = frameDescriptor.addFrameSlot(ident);
-                    frameDescriptor.setFrameSlotKind(slot, FrameSlotKind.Object);
-                    frame.setObject(slot, new PCell());
+            this.callTarget = Truffle.getRuntime().createCallTarget(new RootNode(PythonLanguage.getCurrent()) {
+                @Override
+                public Object execute(VirtualFrame frame) {
+                    return PNone.NONE;
                 }
-            }
-            rootNode = (RootNode) PythonLanguage.getCore().getParser().parse(ParserMode.File, PythonLanguage.getCore(), Source.newBuilder("python", new String(codestring), name).build(), frame);
-            assert rootNode instanceof ModuleRootNode;
+            });
         }
-        this.callTarget = Truffle.getRuntime().createCallTarget(rootNode);
 
         char paramNom = 'A';
         String[] paramNames = new String[argcount];