return the passed obj in PyUnicode_FromObject only if getClass == PString

Author: tomasstupka

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/PythonCextBuiltins.java

@@ -2707,12 +2707,12 @@ protected boolean checkBase(int base) {
     public abstract static class PySequenceTupleNode extends PythonUnaryBuiltinNode {
         @Specialization(guards = "isTuple(obj, getClassNode)")
         public PTuple values(PTuple obj,
-                @SuppressWarnings("unused") @Cached GetClassNode getClassNode) {
+                        @SuppressWarnings("unused") @Cached GetClassNode getClassNode) {
             return obj;
         }
 
         @Specialization(guards = "!isTuple(obj, getClassNode)")
-        public Object values(VirtualFrame frame, Object obj, 
+        public Object values(VirtualFrame frame, Object obj,
                         @Cached TupleNode tupleNode,
                         @SuppressWarnings("unused") @Cached GetClassNode getClassNode,
                         @Cached TransformExceptionToNativeNode transformExceptionToNativeNode,
@@ -2724,7 +2724,7 @@ public Object values(VirtualFrame frame, Object obj,
                 return getNativeNullNode.execute();
             }
         }
-        
+
         protected boolean isTuple(Object obj, GetClassNode getClassNode) {
             return getClassNode.execute(obj) == PythonBuiltinClassType.PTuple;
         }
@@ -3010,12 +3010,13 @@ public String fromObject(String s) {
             return s;
         }
 
-        @Specialization
-        public PString fromObject(PString s) {
+        @Specialization(guards = "isPStringType(s, getClassNode)")
+        public PString fromObject(PString s,
+                        @SuppressWarnings("unused") @Cached GetClassNode getClassNode) {
             return s;
         }
 
-        @Specialization(guards = {"!isString(obj)", "isStringSubtype(frame, obj, getClassNode, isSubtypeNode)"})
+        @Specialization(guards = {"!isPStringType(obj, getClassNode)", "isStringSubtype(frame, obj, getClassNode, isSubtypeNode)"})
         public Object fromObject(VirtualFrame frame, Object obj,
                         @Cached StrNode strNode,
                         @SuppressWarnings("unused") @Cached GetClassNode getClassNode,
@@ -3030,7 +3031,7 @@ public Object fromObject(VirtualFrame frame, Object obj,
             }
         }
 
-        @Specialization(guards = {"!isString(obj)", "!isStringSubtype(frame, obj, getClassNode, isSubtypeNode)"})
+        @Specialization(guards = {"!isStringSubtype(frame, obj, getClassNode, isSubtypeNode)"})
         public Object fromObject(VirtualFrame frame, Object obj,
                         @SuppressWarnings("unused") @Cached GetClassNode getClassNode,
                         @SuppressWarnings("unused") @Cached IsSubtypeNode isSubtypeNode,
@@ -3042,6 +3043,10 @@ public Object fromObject(VirtualFrame frame, Object obj,
         protected boolean isStringSubtype(VirtualFrame frame, Object obj, GetClassNode getClassNode, IsSubtypeNode isSubtypeNode) {
             return isSubtypeNode.execute(frame, getClassNode.execute(obj), PythonBuiltinClassType.PString);
         }
+
+        protected boolean isPStringType(Object obj, GetClassNode getClassNode) {
+            return getClassNode.execute(obj) == PythonBuiltinClassType.PString;
+        }
     }
 
     @Builtin(name = "PyUnicode_GetLength", minNumOfPositionalArgs = 1)