add an option to not call repr in PythonLanguage#toString

Author: timfel

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/PythonLanguage.java

@@ -408,30 +408,32 @@ protected SourceSection findSourceLocation(PythonContext context, Object value)
 
     @Override
     protected String toString(PythonContext context, Object value) {
-        final PythonModule builtins = context.getBuiltins();
-        if (builtins != null) {
-            // may be null during initialization
-            Object reprAttribute = builtins.getAttribute(BuiltinNames.REPR);
-            if (reprAttribute instanceof PBuiltinMethod) {
-                // may be false if e.g. someone accessed our builtins reflectively
-                Object reprFunction = ((PBuiltinMethod) reprAttribute).getFunction();
-                if (reprFunction instanceof PBuiltinFunction) {
-                    // may be false if our builtins were tampered with
-                    Object[] userArgs = PArguments.create(2);
-                    PArguments.setArgument(userArgs, 0, PNone.NONE);
-                    PArguments.setArgument(userArgs, 1, value);
-                    try {
-                        Object result = InvokeNode.invokeUncached((PBuiltinFunction) reprFunction, userArgs);
-                        if (result instanceof String) {
-                            return (String) result;
-                        } else if (result instanceof PString) {
-                            return ((PString) result).getValue();
-                        } else {
-                            // This is illegal for a repr implementation, we ignore the result.
-                            // At this point it's probably difficult to report this properly.
+        if (PythonOptions.getFlag(context, PythonOptions.UseReprForPrintString)) {
+            final PythonModule builtins = context.getBuiltins();
+            if (builtins != null) {
+                // may be null during initialization
+                Object reprAttribute = builtins.getAttribute(BuiltinNames.REPR);
+                if (reprAttribute instanceof PBuiltinMethod) {
+                    // may be false if e.g. someone accessed our builtins reflectively
+                    Object reprFunction = ((PBuiltinMethod) reprAttribute).getFunction();
+                    if (reprFunction instanceof PBuiltinFunction) {
+                        // may be false if our builtins were tampered with
+                        Object[] userArgs = PArguments.create(2);
+                        PArguments.setArgument(userArgs, 0, PNone.NONE);
+                        PArguments.setArgument(userArgs, 1, value);
+                        try {
+                            Object result = InvokeNode.invokeUncached((PBuiltinFunction) reprFunction, userArgs);
+                            if (result instanceof String) {
+                                return (String) result;
+                            } else if (result instanceof PString) {
+                                return ((PString) result).getValue();
+                            } else {
+                                // This is illegal for a repr implementation, we ignore the result.
+                                // At this point it's probably difficult to report this properly.
+                            }
+                        } catch (PException e) {
+                            // Fall through to default
                         }
-                    } catch (PException e) {
-                        // Fall through to default
                     }
                 }
             }
@@ -440,8 +442,12 @@ protected String toString(PythonContext context, Object value) {
         // return a String
         if (value instanceof PythonAbstractObject) {
             return ((PythonAbstractObject) value).toString();
+        } else if (value instanceof String) {
+            return (String) value;
+        } else if (value instanceof Number) {
+            return ((Number) value).toString();
         } else {
-            return "illegal object";
+            return "not a Python object";
         }
     }
 

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PythonOptions.java

@@ -151,6 +151,9 @@ private PythonOptions() {
     @Option(category = OptionCategory.EXPERT, help = "Determines wether context startup tries to re-use previously cached sources of the core library.") //
     public static final OptionKey<Boolean> WithCachedSources = new OptionKey<>(true);
 
+    @Option(category = OptionCategory.EXPERT, help = "Embedder option: what to print in response to PythonLanguage#toString.") //
+    public static final OptionKey<Boolean> UseReprForPrintString = new OptionKey<>(true);
+
     public static OptionDescriptors createDescriptors() {
         return new PythonOptionsOptionDescriptors();
     }