create slots through scope info api

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/parser/ScopeInfo.java

@@ -142,12 +142,14 @@ public FrameSlot findFrameSlot(String identifier) {
         return this.getFrameDescriptor().findFrameSlot(identifier);
     }
 
-    private void createSlotIfNotPresent(String identifier) {
+    FrameSlot createSlotIfNotPresent(String identifier) {
         assert identifier != null : "identifier is null!";
         FrameSlot frameSlot = this.getFrameDescriptor().findFrameSlot(identifier);
         if (frameSlot == null) {
             identifierToIndex.add(identifier);
-            this.getFrameDescriptor().addFrameSlot(identifier);
+            return getFrameDescriptor().addFrameSlot(identifier);
+        } else {
+            return frameSlot;
         }
     }
 

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/parser/TranslationEnvironment.java

@@ -180,7 +180,7 @@ public void createLocal(String name) {
     }
 
     private FrameSlot createAndReturnLocal(String name) {
-        return currentScope.getFrameDescriptor().findOrAddFrameSlot(name);
+        return currentScope.createSlotIfNotPresent(name);
     }
 
     private boolean isCellInCurrentScope(String name) {
@@ -349,7 +349,7 @@ public static FrameSlot makeTempLocalVariable(FrameDescriptor frameDescriptor) {
 
     private void createGlobal(String name) {
         assert name != null : "name is null!";
-        globalScope.getFrameDescriptor().findOrAddFrameSlot(name);
+        globalScope.createSlotIfNotPresent(name);
     }
 
     public void addLocalGlobals(String name) {
@@ -399,7 +399,7 @@ protected ReadDefaultArgumentNode[] getDefaultArgumentReads() {
     }
 
     public FrameSlot getReturnSlot() {
-        return currentScope.getFrameDescriptor().findOrAddFrameSlot(RETURN_SLOT_ID);
+        return currentScope.createSlotIfNotPresent(RETURN_SLOT_ID);
     }
 
     private ScopeInfo findEnclosingClassScope() {