Provide better error message when passing wrong number of arguments.

runtime/vm/resolver.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/resolver.h"
 
 #include "vm/flags.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
@@ skipping 44 matching lines @@
   // in the class.
   Function& function =
       Function::Handle(cls.LookupDynamicFunction(function_name));
   while (function.IsNull()) {
     cls = cls.SuperClass();
     if (cls.IsNull()) break;
     function = cls.LookupDynamicFunction(function_name);
   }
   if (function.IsNull() ||
       !function.AreValidArgumentCounts(num_arguments,
-                                       num_named_arguments)) {
+                                       num_named_arguments,
+                                       NULL,
+                                       0)) {
     // Return a null function to signal to the upper levels to dispatch to
     // "noSuchMethod" function.
     if (FLAG_trace_resolving) {
+      const intptr_t kMessageBufferSize = 256;
+      char message_buffer[kMessageBufferSize] = "function not found";
+      if (!function.IsNull()) {
+        // Obtain more detailed error message.
+        function.AreValidArgumentCounts(num_arguments,
+                                        num_named_arguments,
+                                        message_buffer,
+                                        kMessageBufferSize);
+      }
       OS::Print("ResolveDynamic error '%s': %s.\n",
                 function_name.ToCString(),
-                function.IsNull() ?
-                    "function not found" : "argument count mismatch");
+                message_buffer);
     }
     return Function::null();
   }
   return function.raw();
 }
 
 
 RawFunction* Resolver::ResolveStatic(const Library& library,
                                      const String& class_name,
                                      const String& function_name,
                                      int num_arguments,
                                      const Array& argument_names,
                                      StaticResolveType resolve_type) {
   ASSERT(!library.IsNull());
   Function& function = Function::Handle();
   if (class_name.IsNull() || (class_name.Length() == 0)) {
     // Check if we are referring to a top level function.
     const Object& object = Object::Handle(library.LookupObject(function_name));
     if (!object.IsNull() && object.IsFunction()) {
       function ^= object.raw();
-      if (!function.AreValidArguments(num_arguments, argument_names)) {
+      if (!function.AreValidArguments(num_arguments, argument_names, NULL, 0)) {
         if (FLAG_trace_resolving) {
+          const intptr_t kMessageBufferSize = 256;
+          char message_buffer[kMessageBufferSize];
+          // Obtain more detailed error message.
+          function.AreValidArguments(num_arguments,
+                                     argument_names,
+                                     message_buffer,
+                                     kMessageBufferSize);
           OS::Print("ResolveStatic error '%s': %s.\n",
-                    function_name.ToCString(), "arguments mismatch");
+                    function_name.ToCString(),
+                    message_buffer);
         }
         function = Function::null();
       }
     } else {
       if (FLAG_trace_resolving) {
         OS::Print("ResolveStatic error '%s': %s.\n",
                   function_name.ToCString(), "top level function not found");
       }
     }
   } else {
@@ skipping 42 matching lines @@
 
 
 RawFunction* Resolver::ResolveStatic(const Class&  cls,
                                      const String& function_name,
                                      int num_arguments,
                                      const Array& argument_names,
                                      StaticResolveType resolve_type) {
   const Function& function = Function::Handle(
       ResolveStaticByName(cls, function_name, resolve_type));
   if (function.IsNull() ||
-      !function.AreValidArguments(num_arguments, argument_names)) {
+      !function.AreValidArguments(num_arguments, argument_names, NULL, 0)) {
     // Return a null function to signal to the upper levels to throw a
     // resolution error or maybe throw the error right here.
     if (FLAG_trace_resolving) {
+      const intptr_t kMessageBufferSize = 256;
+      char message_buffer[kMessageBufferSize] = "function not found";
+      if (!function.IsNull()) {
+        // Obtain more detailed error message.
+        function.AreValidArguments(num_arguments,
+                                   argument_names,
+                                   message_buffer,
+                                   kMessageBufferSize);
+      }
       OS::Print("ResolveStatic error '%s': %s.\n",
                 function_name.ToCString(),
-                function.IsNull() ?
-                    "function not found" : "arguments mismatch");
+                message_buffer);
     }
     return Function::null();
   }
   return function.raw();
 }
 
 }  // namespace dart