Add more API fuzzing and fix the issues encountered.

runtime/bin/file.cc

 // Copyright (c) 2012, 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 "bin/file.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 #include "bin/thread.h"
 #include "bin/utils.h"
@@ skipping 61 matching lines @@
   // reading. This is to prevent the opening of directories as
   // files. Directories can be opened for reading using the posix
   // 'open' call.
   File* file = NULL;
   file = File::Open(filename, file_mode);
   if (file != NULL) {
     Dart_SetReturnValue(args,
                         Dart_NewInteger(reinterpret_cast<intptr_t>(file)));
   } else {
     Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) {
-      Dart_PropagateError(err);
-    }
+    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_Exists)(Dart_NativeArguments args) {
   Dart_EnterScope();
   const char* filename =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   bool exists = File::Exists(filename);
   Dart_SetReturnValue(args, Dart_NewBoolean(exists));
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_Close)(Dart_NativeArguments args) {
   Dart_EnterScope();
-  intptr_t return_value = -1;
   intptr_t value =
       DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   File* file = reinterpret_cast<File*>(value);
-  if (file != NULL) {
-    delete file;
-    return_value = 0;
-  }
-  Dart_SetReturnValue(args, Dart_NewInteger(return_value));
+  ASSERT(file != NULL);
+  delete file;
+  Dart_SetReturnValue(args, Dart_NewInteger(0));
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_ReadByte)(Dart_NativeArguments args) {
   Dart_EnterScope();
   intptr_t value =
       DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   File* file = reinterpret_cast<File*>(value);
-  if (file != NULL) {
-    uint8_t buffer;
-    int bytes_read = file->Read(reinterpret_cast<void*>(&buffer), 1);
-    if (bytes_read == 1) {
-      Dart_SetReturnValue(args, Dart_NewInteger(buffer));
-    } else if (bytes_read == 0) {
-      Dart_SetReturnValue(args, Dart_NewInteger(-1));
-    } else {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) {
-        Dart_PropagateError(err);
-      }
-      Dart_SetReturnValue(args, err);
-    }
+  ASSERT(file != NULL);
+  uint8_t buffer;
+  int bytes_read = file->Read(reinterpret_cast<void*>(&buffer), 1);
+  if (bytes_read == 1) {
+    Dart_SetReturnValue(args, Dart_NewInteger(buffer));
+  } else if (bytes_read == 0) {
+    Dart_SetReturnValue(args, Dart_NewInteger(-1));
+  } else {
+    Dart_Handle err = DartUtils::NewDartOSError();
+    if (Dart_IsError(err)) Dart_PropagateError(err);
+    Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_WriteByte)(Dart_NativeArguments args) {
   Dart_EnterScope();
-  intptr_t value =
+  intptr_t file_ptr =
       DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
-  File* file = reinterpret_cast<File*>(value);
-  if (file != NULL) {
-    int64_t value = DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 1));
+  File* file = reinterpret_cast<File*>(file_ptr);
+  ASSERT(file != NULL);

[Søren Gjesse, 2012/05/16 11:54:11]

How about adding a function to do this

int64_t value;
bool valid_argument = DartUtils::SetInt64Value(value_handle, &value);
if (valid_argument) {
  ...


or even


int64_t value;
if (DartUtils::SetInt64Value(value_handle, &value)) {
  ...

[Mads Ager (google), 2012/05/16 12:45:19]

Maybe we should just change GetIntegerValue to do this. I have added a
GetInt64Value that checks. I have kept GetIntegerValue for now. I will phase out
its use going forward.

+  Dart_Handle value_handle = Dart_GetNativeArgument(args, 1);
+  bool valid_argument = Dart_IsInteger(value_handle);
+  if (valid_argument) {
+    Dart_IntegerFitsIntoInt64(value_handle, &valid_argument);
+  }
+  if (valid_argument) {
+    int64_t value = DartUtils::GetIntegerValue(value_handle);
     uint8_t buffer = static_cast<uint8_t>(value & 0xff);
     int bytes_written = file->Write(reinterpret_cast<void*>(&buffer), 1);
     if (bytes_written >= 0) {
       Dart_SetReturnValue(args, Dart_NewInteger(bytes_written));
     } else {
       Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) {
-        Dart_PropagateError(err);
-      }
+      if (Dart_IsError(err)) Dart_PropagateError(err);
       Dart_SetReturnValue(args, err);
     }
+  } else {
+    OSError os_error(-1, "Invalid argument", OSError::kUnknown);
+    Dart_Handle err = DartUtils::NewDartOSError(&os_error);
+    if (Dart_IsError(err)) Dart_PropagateError(err);
+    Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_WriteString)(Dart_NativeArguments args) {
   Dart_EnterScope();
   intptr_t value =
       DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   File* file = reinterpret_cast<File*>(value);
-  if (file != NULL) {
-    const char* str =
-        DartUtils::GetStringValue(Dart_GetNativeArgument(args, 1));
-    int bytes_written = file->Write(reinterpret_cast<const void*>(str),
-                                    strlen(str));
-    if (bytes_written >= 0) {
-      Dart_SetReturnValue(args, Dart_NewInteger(bytes_written));
-    } else {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) {
-        Dart_PropagateError(err);
-      }
-      Dart_SetReturnValue(args, err);
-    }
+  ASSERT(file != NULL);
+  const char* str =
+      DartUtils::GetStringValue(Dart_GetNativeArgument(args, 1));
+  int bytes_written = file->Write(reinterpret_cast<const void*>(str),
+                                  strlen(str));
+  if (bytes_written >= 0) {
+    Dart_SetReturnValue(args, Dart_NewInteger(bytes_written));
+  } else {
+    Dart_Handle err = DartUtils::NewDartOSError();
+    if (Dart_IsError(err)) Dart_PropagateError(err);
+    Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_ReadList)(Dart_NativeArguments args) {
   Dart_EnterScope();
   intptr_t value =
       DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   File* file = reinterpret_cast<File*>(value);
-  if (file != NULL) {
-    Dart_Handle buffer_obj = Dart_GetNativeArgument(args, 1);
-    ASSERT(Dart_IsList(buffer_obj));
-    int64_t offset =
-        DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 2));
-    int64_t length =
-        DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 3));
-    intptr_t array_len = 0;
-    Dart_Handle result = Dart_ListLength(buffer_obj, &array_len);
+  ASSERT(file != NULL);
+  Dart_Handle buffer_obj = Dart_GetNativeArgument(args, 1);
+  ASSERT(Dart_IsList(buffer_obj));
+  int64_t offset =
+      DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 2));
+  int64_t length =
+      DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 3));
+  intptr_t array_len = 0;
+  Dart_Handle result = Dart_ListLength(buffer_obj, &array_len);
+  if (Dart_IsError(result)) Dart_PropagateError(result);
+  ASSERT((offset + length) <= array_len);
+  uint8_t* buffer = new uint8_t[length];
+  int bytes_read = file->Read(reinterpret_cast<void*>(buffer), length);
+  if (bytes_read >= 0) {
+    result =

[Søren Gjesse, 2012/05/16 11:54:11]

Fits one line?

[Mads Ager (google), 2012/05/16 12:45:19]

Done.

+        Dart_ListSetAsBytes(buffer_obj, offset, buffer, bytes_read);
     if (Dart_IsError(result)) {
+      delete[] buffer;
       Dart_PropagateError(result);
     }
-    ASSERT((offset + length) <= array_len);
-    uint8_t* buffer = new uint8_t[length];
-    int bytes_read = file->Read(reinterpret_cast<void*>(buffer), length);
-    if (bytes_read >= 0) {
-      result =
-          Dart_ListSetAsBytes(buffer_obj, offset, buffer, bytes_read);
-      if (Dart_IsError(result)) {
-        delete[] buffer;
-        Dart_PropagateError(result);
-      }
-      Dart_SetReturnValue(args, Dart_NewInteger(bytes_read));
-    } else {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) {
-        Dart_PropagateError(err);
-      }
-      Dart_SetReturnValue(args, err);
-    }
-    delete[] buffer;
+    Dart_SetReturnValue(args, Dart_NewInteger(bytes_read));
+  } else {
+    Dart_Handle err = DartUtils::NewDartOSError();
+    if (Dart_IsError(err)) Dart_PropagateError(err);
+    Dart_SetReturnValue(args, err);
   }
+  delete[] buffer;
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_WriteList)(Dart_NativeArguments args) {
   Dart_EnterScope();
   intptr_t value =
       DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   File* file = reinterpret_cast<File*>(value);
-  if (file != NULL) {
-    Dart_Handle buffer_obj = Dart_GetNativeArgument(args, 1);
-    ASSERT(Dart_IsList(buffer_obj));
-    int64_t offset =
-        DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 2));
-    int64_t length =
-        DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 3));
-    intptr_t buffer_len = 0;
-    Dart_Handle result = Dart_ListLength(buffer_obj, &buffer_len);
-    if (Dart_IsError(result)) {
-      Dart_PropagateError(result);
-    }
-    ASSERT((offset + length) <= buffer_len);
-    uint8_t* buffer = new uint8_t[length];
-    result = Dart_ListGetAsBytes(buffer_obj, offset, buffer, length);
-    if (Dart_IsError(result)) {
-      delete[] buffer;
-      Dart_PropagateError(result);
-    }
-    int bytes_written = file->Write(reinterpret_cast<void*>(buffer), length);
-    if (bytes_written >= 0) {
-      Dart_SetReturnValue(args, Dart_NewInteger(bytes_written));
-    } else {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) {
-        Dart_PropagateError(err);
-      }
-      Dart_SetReturnValue(args, err);
-    }
+  ASSERT(file != NULL);
+  Dart_Handle buffer_obj = Dart_GetNativeArgument(args, 1);
+  ASSERT(Dart_IsList(buffer_obj));
+  int64_t offset =
+      DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 2));

[Søren Gjesse, 2012/05/16 11:54:11]

Shouldn't we check more here? DartUtils::GetIntegerValue use a number of asserts
- like for WriteByte above?

[Mads Ager (google), 2012/05/16 12:45:19]

Oh, yes, here and many other places. I just haven't gotten around to this one
yet. I just change the file != NULL case to an assert. Stay tuned for this one.
:)

+  int64_t length =
+      DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 3));
+  intptr_t buffer_len = 0;
+  Dart_Handle result = Dart_ListLength(buffer_obj, &buffer_len);
+  if (Dart_IsError(result)) Dart_PropagateError(result);
+  ASSERT((offset + length) <= buffer_len);
+  uint8_t* buffer = new uint8_t[length];
+  result = Dart_ListGetAsBytes(buffer_obj, offset, buffer, length);
+  if (Dart_IsError(result)) {
     delete[] buffer;
+    Dart_PropagateError(result);
   }
+  int bytes_written = file->Write(reinterpret_cast<void*>(buffer), length);
+  if (bytes_written >= 0) {
+    Dart_SetReturnValue(args, Dart_NewInteger(bytes_written));
+  } else {
+    Dart_Handle err = DartUtils::NewDartOSError();
+    if (Dart_IsError(err)) Dart_PropagateError(err);
+    Dart_SetReturnValue(args, err);
+  }
+  delete[] buffer;
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_Position)(Dart_NativeArguments args) {
   Dart_EnterScope();
   intptr_t value =
       DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   File* file = reinterpret_cast<File*>(value);
-  if (file != NULL) {
-    intptr_t return_value = file->Position();
-    if (return_value >= 0) {
-      Dart_SetReturnValue(args, Dart_NewInteger(return_value));
-    } else {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) {
-        Dart_PropagateError(err);
-      }
-      Dart_SetReturnValue(args, err);
-    }
+  ASSERT(file != NULL);
+  intptr_t return_value = file->Position();
+  if (return_value >= 0) {
+    Dart_SetReturnValue(args, Dart_NewInteger(return_value));
+  } else {
+    Dart_Handle err = DartUtils::NewDartOSError();
+    if (Dart_IsError(err)) Dart_PropagateError(err);
+    Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_SetPosition)(Dart_NativeArguments args) {
   Dart_EnterScope();
   intptr_t value =
       DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   File* file = reinterpret_cast<File*>(value);
-  if (file != NULL) {
-    int64_t position =
-        DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 1));
+  ASSERT(file != NULL);
+  Dart_Handle pos_handle = Dart_GetNativeArgument(args, 1);
+  bool valid_argument = false;
+  if (Dart_IsInteger(pos_handle)) {
+    Dart_IntegerFitsIntoInt64(pos_handle, &valid_argument);
+  }
+  if (valid_argument) {
+    int64_t position = DartUtils::GetIntegerValue(pos_handle);
     if (file->SetPosition(position)) {
       Dart_SetReturnValue(args, Dart_True());
     } else {
       Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) {
-        Dart_PropagateError(err);
-      }
+      if (Dart_IsError(err)) Dart_PropagateError(err);
       Dart_SetReturnValue(args, err);
     }
+  } else {
+    OSError os_error(-1, "Invalid argument", OSError::kUnknown);
+    Dart_Handle err = DartUtils::NewDartOSError(&os_error);
+    if (Dart_IsError(err)) Dart_PropagateError(err);
+    Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_Truncate)(Dart_NativeArguments args) {
   Dart_EnterScope();
   intptr_t value =
       DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   File* file = reinterpret_cast<File*>(value);
-  if (file != NULL) {
-    int64_t length =
-        DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 1));
-    if (file->Truncate(length)) {
-      Dart_SetReturnValue(args, Dart_True());
-    } else {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) {
-        Dart_PropagateError(err);
-      }
-      Dart_SetReturnValue(args, err);
-    }
+  ASSERT(file != NULL);
+  int64_t length =
+      DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 1));
+  if (file->Truncate(length)) {
+    Dart_SetReturnValue(args, Dart_True());
+  } else {
+    Dart_Handle err = DartUtils::NewDartOSError();
+    if (Dart_IsError(err)) Dart_PropagateError(err);
+    Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_Length)(Dart_NativeArguments args) {
   Dart_EnterScope();
   intptr_t value =
       DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   File* file = reinterpret_cast<File*>(value);
-  if (file != NULL) {
-    intptr_t return_value = file->Length();
-    if (return_value >= 0) {
-      Dart_SetReturnValue(args, Dart_NewInteger(return_value));
-    } else {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) {
-        Dart_PropagateError(err);
-      }
-      Dart_SetReturnValue(args, err);
-    }
+  ASSERT(file != NULL);
+  intptr_t return_value = file->Length();
+  if (return_value >= 0) {
+    Dart_SetReturnValue(args, Dart_NewInteger(return_value));
+  } else {
+    Dart_Handle err = DartUtils::NewDartOSError();
+    if (Dart_IsError(err)) Dart_PropagateError(err);
+    Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_LengthFromName)(Dart_NativeArguments args) {
   Dart_EnterScope();
   const char* name =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   intptr_t return_value = File::LengthFromName(name);
   if (return_value >= 0) {
     Dart_SetReturnValue(args, Dart_NewInteger(return_value));
   } else {
     Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) {
-      Dart_PropagateError(err);
-    }
+    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_Flush)(Dart_NativeArguments args) {
   Dart_EnterScope();
   intptr_t value =
       DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   File* file = reinterpret_cast<File*>(value);
-  if (file != NULL) {
-    if (file->Flush()) {
-      Dart_SetReturnValue(args, Dart_True());
-    } else {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) {
-        Dart_PropagateError(err);
-      }
-      Dart_SetReturnValue(args, err);
-    }
+  ASSERT(file != NULL);
+  if (file->Flush()) {
+    Dart_SetReturnValue(args, Dart_True());
+  } else {
+    Dart_Handle err = DartUtils::NewDartOSError();
+    if (Dart_IsError(err)) Dart_PropagateError(err);
+    Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_Create)(Dart_NativeArguments args) {
   Dart_EnterScope();
   const char* str =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   bool result = File::Create(str);
   if (result) {
     Dart_SetReturnValue(args, Dart_NewBoolean(result));
   } else {
     Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) {
-      Dart_PropagateError(err);
-    }
+    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_Delete)(Dart_NativeArguments args) {
   Dart_EnterScope();
   const char* str =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   bool result = File::Delete(str);
   if (result) {
     Dart_SetReturnValue(args, Dart_NewBoolean(result));
   } else {
     Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) {
-      Dart_PropagateError(err);
-    }
+    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_Directory)(Dart_NativeArguments args) {
   Dart_EnterScope();
   const char* str =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   char* str_copy = strdup(str);
   char* path = File::GetContainingDirectory(str_copy);
   free(str_copy);
   if (path != NULL) {
     Dart_SetReturnValue(args, Dart_NewString(path));
     free(path);
   } else {
     Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) {
-      Dart_PropagateError(err);
-    }
+    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_FullPath)(Dart_NativeArguments args) {
   Dart_EnterScope();
   const char* str =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   char* path = File::GetCanonicalPath(str);
   if (path != NULL) {
     Dart_SetReturnValue(args, Dart_NewString(path));
     free(path);
   } else {
     Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) {
-      Dart_PropagateError(err);
-    }
+    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_SetReturnValue(args, err);
   }
   Dart_ExitScope();
 }
 
 
 void FUNCTION_NAME(File_OpenStdio)(Dart_NativeArguments args) {
   Dart_EnterScope();
   int fd = DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   File* file = File::OpenStdio(fd);
@@ skipping 121 matching lines @@
     }
   }
   return CObject::Null();
 }
 
 
 static CObject* FileCloseRequest(const CObjectArray& request) {
   intptr_t return_value = -1;
   if (request.Length() == 2 && request[1]->IsIntptr()) {
     File* file = CObjectToFilePointer(request[1]);
-    if (file != NULL) {
-      delete file;
-      return_value = 0;
-    }
+    ASSERT(file != NULL);
+    delete file;
+    return_value = 0;
   }
   return new CObjectIntptr(CObject::NewIntptr(return_value));
 }
 
 
 static CObject* FilePositionRequest(const CObjectArray& request) {
   if (request.Length() == 2 && request[1]->IsIntptr()) {
     File* file = CObjectToFilePointer(request[1]);
-    if (file != NULL && !file->IsClosed()) {
+    ASSERT(file != NULL);
+    if (!file->IsClosed()) {
       intptr_t return_value = file->Position();
       if (return_value >= 0) {
         return new CObjectIntptr(CObject::NewIntptr(return_value));
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 static CObject* FileSetPositionRequest(const CObjectArray& request) {
   if (request.Length() == 3 &&
       request[1]->IsIntptr() &&
       request[2]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[1]);
-    if (file != NULL && !file->IsClosed()) {
+    ASSERT(file != NULL);
+    if (!file->IsClosed()) {
       int64_t position = CObjectInt32OrInt64ToInt64(request[2]);
       if (file->SetPosition(position)) {
         return CObject::True();
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 static CObject* FileTruncateRequest(const CObjectArray& request) {
   if (request.Length() == 3 &&
       request[1]->IsIntptr() &&
       request[2]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[1]);
-    if (file != NULL && !file->IsClosed()) {
+    ASSERT(file != NULL);
+    if (!file->IsClosed()) {
       int64_t length = CObjectInt32OrInt64ToInt64(request[2]);
       if (file->Truncate(length)) {
         return CObject::True();
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 static CObject* FileLengthRequest(const CObjectArray& request) {
   if (request.Length() == 2 && request[1]->IsIntptr()) {
     File* file = CObjectToFilePointer(request[1]);
-    if (file != NULL && !file->IsClosed()) {
+    ASSERT(file != NULL);
+    if (!file->IsClosed()) {
       intptr_t return_value = file->Length();
       if (return_value >= 0) {
         return new CObjectIntptr(CObject::NewIntptr(return_value));
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 static CObject* FileLengthFromNameRequest(const CObjectArray& request) {
   if (request.Length() == 2 && request[1]->IsString()) {
     CObjectString filename(request[1]);
     intptr_t return_value = File::LengthFromName(filename.CString());
     if (return_value >= 0) {
       return new CObjectIntptr(CObject::NewIntptr(return_value));
     } else {
       return CObject::NewOSError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 static CObject* FileFlushRequest(const CObjectArray& request) {
-  intptr_t return_value = -1;
   if (request.Length() == 2 && request[1]->IsIntptr()) {
     File* file = CObjectToFilePointer(request[1]);
-    if (file != NULL && !file->IsClosed()) {
+    ASSERT(file != NULL);
+    if (!file->IsClosed()) {
       if (file->Flush()) {
         return CObject::True();
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
-  return new CObjectIntptr(CObject::NewIntptr(return_value));
 }
 
 
 static CObject* FileReadByteRequest(const CObjectArray& request) {
   if (request.Length() == 2 && request[1]->IsIntptr()) {
     File* file = CObjectToFilePointer(request[1]);
-    if (file != NULL && !file->IsClosed()) {
+    ASSERT(file != NULL);
+    if (!file->IsClosed()) {
       uint8_t buffer;
       int bytes_read = file->Read(reinterpret_cast<void*>(&buffer), 1);
       if (bytes_read > 0) {
         return new CObjectIntptr(CObject::NewIntptr(buffer));
       } else if (bytes_read == 0) {
         return new CObjectIntptr(CObject::NewIntptr(-1));
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 static CObject* FileWriteByteRequest(const CObjectArray& request) {
   if (request.Length() == 3 &&
       request[1]->IsIntptr() &&
       request[2]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[1]);
-    if (file != NULL && !file->IsClosed()) {
+    ASSERT(file != NULL);
+    if (!file->IsClosed()) {
       int64_t byte = CObjectInt32OrInt64ToInt64(request[2]);
       uint8_t buffer = static_cast<uint8_t>(byte & 0xff);
       int bytes_written = file->Write(reinterpret_cast<void*>(&buffer), 1);
       if (bytes_written > 0) {
         return new CObjectIntptr(CObject::NewIntptr(bytes_written));
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 static CObject* FileReadListRequest(const CObjectArray& request) {
   if (request.Length() == 3 &&
       request[1]->IsIntptr() &&
       request[2]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[1]);
-    if (file != NULL && !file->IsClosed()) {
+    ASSERT(file != NULL);
+    if (!file->IsClosed()) {
       int64_t length = CObjectInt32OrInt64ToInt64(request[2]);
       CObjectUint8Array* byte_array =
           new CObjectUint8Array(CObject::NewUint8Array(length));
       void* buffer = reinterpret_cast<void*>(byte_array->Buffer());
       int bytes_read = file->Read(buffer, byte_array->Length());
       if (bytes_read >= 0) {
         CObjectArray* result = new CObjectArray(CObject::NewArray(3));
         result->SetAt(0, new CObjectIntptr(CObject::NewInt32(0)));
         result->SetAt(1, new CObjectIntptr(CObject::NewIntptr(bytes_read)));
         result->SetAt(2, byte_array);
         return result;
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 static CObject* FileWriteListRequest(const CObjectArray& request) {
   if (request.Length() == 5 &&
       request[1]->IsIntptr() &&
       (request[2]->IsUint8Array() || request[2]->IsArray()) &&
       request[3]->IsInt32OrInt64() &&
       request[4]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[1]);
-    if (file != NULL && !file->IsClosed()) {
+    ASSERT(file != NULL);
+    if (!file->IsClosed()) {
       int64_t offset = CObjectInt32OrInt64ToInt64(request[3]);
       int64_t length = CObjectInt32OrInt64ToInt64(request[4]);
       uint8_t* buffer_start;
       if (request[2]->IsUint8Array()) {
         CObjectUint8Array byte_array(request[2]);
         buffer_start = byte_array.Buffer() + offset;
       } else {
         CObjectArray array(request[2]);
         buffer_start = new uint8_t[length];
         for (int i = 0; i < length; i++) {
@@ skipping 24 matching lines @@
   }
   return CObject::IllegalArgumentError();
 }
 
 
 static CObject* FileWriteStringRequest(const CObjectArray& request) {
   if (request.Length() == 3 &&
       request[1]->IsIntptr() &&
       request[2]->IsString()) {
     File* file = CObjectToFilePointer(request[1]);
-    if (file != NULL && !file->IsClosed()) {
+    ASSERT(file != NULL);
+    if (!file->IsClosed()) {
       CObjectString str(request[2]);
       const void* buffer = reinterpret_cast<const void*>(str.CString());
       int64_t bytes_written = file->Write(buffer, str.Length());
       return new CObjectInt64(CObject::NewInt64(bytes_written));
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
@@ skipping 101 matching lines @@
   Dart_EnterScope();
   Dart_SetReturnValue(args, Dart_Null());
   Dart_Port service_port = File::GetServicePort();
   if (service_port != kIllegalPort) {
     // Return a send port for the service port.
     Dart_Handle send_port = Dart_NewSendPort(service_port);
     Dart_SetReturnValue(args, send_port);
   }
   Dart_ExitScope();
 }