Prefer Dart_SetReturnValue over Dart_PropagateError when it makes sense.

runtime/bin/file.cc

 // Copyright (c) 2013, 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/embedded_dart_io.h"
 #include "bin/io_buffer.h"
@@ skipping 118 matching lines @@
   // Check that the file exists before opening it only for
   // 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);
-    Dart_SetReturnValue(args, err);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_Exists)(Dart_NativeArguments args) {
   const char* filename =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   bool exists = File::Exists(filename);
   Dart_SetReturnValue(args, Dart_NewBoolean(exists));
 }
@@ skipping 17 matching lines @@
 void FUNCTION_NAME(File_ReadByte)(Dart_NativeArguments args) {
   File* file = GetFilePointer(Dart_GetNativeArgument(args, 0));
   ASSERT(file != NULL);
   uint8_t buffer;
   int64_t 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_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_WriteByte)(Dart_NativeArguments args) {
   File* file = GetFilePointer(Dart_GetNativeArgument(args, 0));
   ASSERT(file != NULL);
   int64_t byte = 0;
   if (DartUtils::GetInt64Value(Dart_GetNativeArgument(args, 1), &byte)) {
     uint8_t buffer = static_cast<uint8_t>(byte & 0xff);
     bool success = file->WriteFully(reinterpret_cast<void*>(&buffer), 1);
     if (success) {
       Dart_SetReturnValue(args, Dart_NewInteger(1));
     } else {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) Dart_PropagateError(err);
-      Dart_SetReturnValue(args, err);
+      Dart_SetReturnValue(args, DartUtils::NewDartOSError());
     }
   } 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_SetReturnValue(args, DartUtils::NewDartOSError(&os_error));
   }
 }
 
 
 void FUNCTION_NAME(File_Read)(Dart_NativeArguments args) {
   File* file = GetFilePointer(Dart_GetNativeArgument(args, 0));
   ASSERT(file != NULL);
   Dart_Handle length_object = Dart_GetNativeArgument(args, 1);
   int64_t length = 0;
   if (DartUtils::GetInt64Value(length_object, &length)) {
     uint8_t* buffer = NULL;
     Dart_Handle external_array = IOBuffer::Allocate(length, &buffer);
     int64_t bytes_read = file->Read(reinterpret_cast<void*>(buffer), length);
     if (bytes_read < 0) {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) Dart_PropagateError(err);
-      Dart_SetReturnValue(args, err);
+      Dart_SetReturnValue(args, DartUtils::NewDartOSError());
     } else {
       if (bytes_read < length) {
         const int kNumArgs = 3;
         Dart_Handle dart_args[kNumArgs];
         dart_args[0] = external_array;
         dart_args[1] = Dart_NewInteger(0);
         dart_args[2] = Dart_NewInteger(bytes_read);
         // TODO(sgjesse): Cache the _makeUint8ListView function somewhere.
         Dart_Handle io_lib =
             Dart_LookupLibrary(DartUtils::NewString("dart:io"));
         if (Dart_IsError(io_lib)) Dart_PropagateError(io_lib);
         Dart_Handle array_view =
             Dart_Invoke(io_lib,
                         DartUtils::NewString("_makeUint8ListView"),
                         kNumArgs,
                         dart_args);
-        if (Dart_IsError(array_view)) Dart_PropagateError(array_view);
         Dart_SetReturnValue(args, array_view);
       } else {
         Dart_SetReturnValue(args, external_array);
       }
     }
   } 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_SetReturnValue(args, DartUtils::NewDartOSError(&os_error));
   }
 }
 
 
 void FUNCTION_NAME(File_ReadInto)(Dart_NativeArguments args) {
   File* file = GetFilePointer(Dart_GetNativeArgument(args, 0));
   ASSERT(file != NULL);
   Dart_Handle buffer_obj = Dart_GetNativeArgument(args, 1);
   ASSERT(Dart_IsList(buffer_obj));
   // start and end arguments are checked in Dart code to be
   // integers and have the property that end <=
   // list.length. Therefore, it is safe to extract their value as
   // intptr_t.
   intptr_t start =
       DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 2));
   intptr_t end =
       DartUtils::GetIntptrValue(Dart_GetNativeArgument(args, 3));
   intptr_t length = end - start;
   intptr_t array_len = 0;
   Dart_Handle result = Dart_ListLength(buffer_obj, &array_len);
   if (Dart_IsError(result)) Dart_PropagateError(result);
   ASSERT(end <= array_len);
   uint8_t* buffer = new uint8_t[length];
   int64_t bytes_read = file->Read(reinterpret_cast<void*>(buffer), length);
   if (bytes_read >= 0) {
     result = Dart_ListSetAsBytes(buffer_obj, start, buffer, bytes_read);
     if (Dart_IsError(result)) {
-      delete[] buffer;
-      Dart_PropagateError(result);
+      Dart_SetReturnValue(args, result);
+    } else {
+      Dart_SetReturnValue(args, Dart_NewInteger(bytes_read));
     }
-    Dart_SetReturnValue(args, Dart_NewInteger(bytes_read));
   } else {
-    Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) Dart_PropagateError(err);
-    Dart_SetReturnValue(args, err);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
   delete[] buffer;
 }
 
 
 void FUNCTION_NAME(File_WriteFrom)(Dart_NativeArguments args) {
   File* file = GetFilePointer(Dart_GetNativeArgument(args, 0));
   ASSERT(file != NULL);
 
   Dart_Handle buffer_obj = Dart_GetNativeArgument(args, 1);
@@ skipping 22 matching lines @@
   ASSERT(buffer != NULL);
 
   // Write all the data out into the file.
   bool success = file->WriteFully(buffer, length);
 
   // Release the direct pointer acquired above.
   result = Dart_TypedDataReleaseData(buffer_obj);
   if (Dart_IsError(result)) Dart_PropagateError(result);
 
   if (!success) {
-    Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) Dart_PropagateError(err);
-    Dart_SetReturnValue(args, err);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   } else {
     Dart_SetReturnValue(args, Dart_Null());
   }
 }
 
 
 void FUNCTION_NAME(File_Position)(Dart_NativeArguments args) {
   File* file = GetFilePointer(Dart_GetNativeArgument(args, 0));
   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_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_SetPosition)(Dart_NativeArguments args) {
   File* file = GetFilePointer(Dart_GetNativeArgument(args, 0));
   ASSERT(file != NULL);
   int64_t position = 0;
   if (DartUtils::GetInt64Value(Dart_GetNativeArgument(args, 1), &position)) {
     if (file->SetPosition(position)) {
       Dart_SetReturnValue(args, Dart_True());
     } else {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) Dart_PropagateError(err);
-      Dart_SetReturnValue(args, err);
+      Dart_SetReturnValue(args, DartUtils::NewDartOSError());
     }
   } 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_SetReturnValue(args, DartUtils::NewDartOSError(&os_error));
   }
 }
 
 
 void FUNCTION_NAME(File_Truncate)(Dart_NativeArguments args) {
   File* file = GetFilePointer(Dart_GetNativeArgument(args, 0));
   ASSERT(file != NULL);
   int64_t length = 0;
   if (DartUtils::GetInt64Value(Dart_GetNativeArgument(args, 1), &length)) {
     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_SetReturnValue(args, DartUtils::NewDartOSError());
     }
   } 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_SetReturnValue(args, DartUtils::NewDartOSError(&os_error));
   }
 }
 
 
 void FUNCTION_NAME(File_Length)(Dart_NativeArguments args) {
   File* file = GetFilePointer(Dart_GetNativeArgument(args, 0));
   ASSERT(file != NULL);
   int64_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_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_LengthFromPath)(Dart_NativeArguments args) {
   const char* path =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   int64_t return_value = File::LengthFromPath(path);
   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_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_LastModified)(Dart_NativeArguments args) {
   const char* name =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   int64_t return_value = File::LastModified(name);
   if (return_value >= 0) {
     Dart_SetReturnValue(args, Dart_NewInteger(return_value * kMSPerSecond));
   } else {
-    Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) Dart_PropagateError(err);
-    Dart_SetReturnValue(args, err);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_Flush)(Dart_NativeArguments args) {
   File* file = GetFilePointer(Dart_GetNativeArgument(args, 0));
   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_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_Lock)(Dart_NativeArguments args) {
   File* file = GetFilePointer(Dart_GetNativeArgument(args, 0));
   ASSERT(file != NULL);
   int64_t lock;
   int64_t start;
   int64_t end;
   if (DartUtils::GetInt64Value(Dart_GetNativeArgument(args, 1), &lock) &&
       DartUtils::GetInt64Value(Dart_GetNativeArgument(args, 2), &start) &&
       DartUtils::GetInt64Value(Dart_GetNativeArgument(args, 3), &end)) {
     if ((lock >= File::kLockMin) && (lock <= File::kLockMax) &&
         (start >= 0) && (end == -1 || end > start)) {
       if (file->Lock(static_cast<File::LockType>(lock), start, end)) {
         Dart_SetReturnValue(args, Dart_True());
       } else {
-        Dart_Handle err = DartUtils::NewDartOSError();
-        if (Dart_IsError(err)) Dart_PropagateError(err);
-        Dart_SetReturnValue(args, err);
+        Dart_SetReturnValue(args, DartUtils::NewDartOSError());
       }
       return;
     }
   }
-
   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_SetReturnValue(args, DartUtils::NewDartOSError(&os_error));
 }
 
 
 void FUNCTION_NAME(File_Create)(Dart_NativeArguments args) {
   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);
-    Dart_SetReturnValue(args, err);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_CreateLink)(Dart_NativeArguments args) {
   if (Dart_IsString(Dart_GetNativeArgument(args, 0)) &&
       Dart_IsString(Dart_GetNativeArgument(args, 1))) {
     const char* name =
         DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
     const char* target =
         DartUtils::GetStringValue(Dart_GetNativeArgument(args, 1));
     if (!File::CreateLink(name, target)) {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) Dart_PropagateError(err);
-      Dart_SetReturnValue(args, err);
+      Dart_SetReturnValue(args, DartUtils::NewDartOSError());
     }
   } else  {
     Dart_Handle err = DartUtils::NewDartArgumentError(
         "Non-string argument to Link.create");
-    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_SetReturnValue(args, err);
   }
 }
 
 
 void FUNCTION_NAME(File_LinkTarget)(Dart_NativeArguments args) {
   if (Dart_IsString(Dart_GetNativeArgument(args, 0))) {
     const char* name =
         DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
     char* target = File::LinkTarget(name);
     if (target == NULL) {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) Dart_PropagateError(err);
-      Dart_SetReturnValue(args, err);
+      Dart_SetReturnValue(args, DartUtils::NewDartOSError());
     } else {
       Dart_SetReturnValue(args, DartUtils::NewString(target));
       free(target);
     }
   } else {
     Dart_Handle err = DartUtils::NewDartArgumentError(
         "Non-string argument to Link.target");
-    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_SetReturnValue(args, err);
   }
 }
 
 
 void FUNCTION_NAME(File_Delete)(Dart_NativeArguments args) {
   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);
-    Dart_SetReturnValue(args, err);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_DeleteLink)(Dart_NativeArguments args) {
   const char* str =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   bool result = File::DeleteLink(str);
   if (result) {
     Dart_SetReturnValue(args, Dart_NewBoolean(result));
   } else {
-    Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) Dart_PropagateError(err);
-    Dart_SetReturnValue(args, err);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_Rename)(Dart_NativeArguments args) {
   const char* old_path =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   const char* new_path =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 1));
   bool result = File::Rename(old_path, new_path);
   if (result) {
     Dart_SetReturnValue(args, Dart_NewBoolean(result));
   } else {
-    Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) Dart_PropagateError(err);
-    Dart_SetReturnValue(args, err);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_RenameLink)(Dart_NativeArguments args) {
   const char* old_path =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   const char* new_path =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 1));
   bool result = File::RenameLink(old_path, new_path);
   if (result) {
     Dart_SetReturnValue(args, Dart_NewBoolean(result));
   } else {
-    Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) Dart_PropagateError(err);
-    Dart_SetReturnValue(args, err);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_Copy)(Dart_NativeArguments args) {
   const char* old_path =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   const char* new_path =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 1));
   bool result = File::Copy(old_path, new_path);
   if (result) {
     Dart_SetReturnValue(args, Dart_NewBoolean(result));
   } else {
-    Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) Dart_PropagateError(err);
-    Dart_SetReturnValue(args, err);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_ResolveSymbolicLinks)(Dart_NativeArguments args) {
   const char* str =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   char* path = File::GetCanonicalPath(str);
   if (path != NULL) {
     Dart_SetReturnValue(args, DartUtils::NewString(path));
     free(path);
   } else {
-    Dart_Handle err = DartUtils::NewDartOSError();
-    if (Dart_IsError(err)) Dart_PropagateError(err);
-    Dart_SetReturnValue(args, err);
+    Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_OpenStdio)(Dart_NativeArguments args) {
   int64_t fd = DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 0));
   ASSERT(fd == STDIN_FILENO || fd == STDOUT_FILENO || fd == STDERR_FILENO);
   File* file = File::OpenStdio(static_cast<int>(fd));
   Dart_SetReturnValue(args, Dart_NewInteger(reinterpret_cast<intptr_t>(file)));
 }
@@ skipping 12 matching lines @@
       Dart_IsBoolean(Dart_GetNativeArgument(args, 1))) {
     const char* str =
         DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
     bool follow_links =
         DartUtils::GetBooleanValue(Dart_GetNativeArgument(args, 1));
     File::Type type = File::GetType(str, follow_links);
     Dart_SetReturnValue(args, Dart_NewInteger(static_cast<int>(type)));
   } else  {
     Dart_Handle err = DartUtils::NewDartArgumentError(
         "Non-string argument to FileSystemEntity.type");
-    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_SetReturnValue(args, err);
   }
 }
 
 
 void FUNCTION_NAME(File_Stat)(Dart_NativeArguments args) {
   if (Dart_IsString(Dart_GetNativeArgument(args, 0))) {
     const char* path =
         DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
 
     int64_t stat_data[File::kStatSize];
     File::Stat(path, stat_data);
     if (stat_data[File::kType] == File::kDoesNotExist) {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) Dart_PropagateError(err);
-      Dart_SetReturnValue(args, err);
+      Dart_SetReturnValue(args, DartUtils::NewDartOSError());
     } else {
       Dart_Handle returned_data = Dart_NewTypedData(Dart_TypedData_kInt64,
                                                     File::kStatSize);
       if (Dart_IsError(returned_data)) Dart_PropagateError(returned_data);
       Dart_TypedData_Type data_type_unused;
       void* data_location;
       intptr_t data_length_unused;
       Dart_Handle status = Dart_TypedDataAcquireData(returned_data,
                                                      &data_type_unused,
                                                      &data_location,
                                                      &data_length_unused);
       if (Dart_IsError(status)) Dart_PropagateError(status);
       memmove(data_location, stat_data, File::kStatSize * sizeof(int64_t));
       status = Dart_TypedDataReleaseData(returned_data);
       if (Dart_IsError(status)) Dart_PropagateError(status);
       Dart_SetReturnValue(args, returned_data);
     }
   } else {
     Dart_Handle err = DartUtils::NewDartArgumentError(
         "Non-string argument to FileSystemEntity.stat");
-    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_SetReturnValue(args, err);
   }
 }
 
 
 void FUNCTION_NAME(File_AreIdentical)(Dart_NativeArguments args) {
   if (Dart_IsString(Dart_GetNativeArgument(args, 0)) &&
       Dart_IsString(Dart_GetNativeArgument(args, 1))) {
     const char* path_1 =
         DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
     const char* path_2 =
         DartUtils::GetStringValue(Dart_GetNativeArgument(args, 1));
     File::Identical result = File::AreIdentical(path_1, path_2);
     if (result == File::kError) {
-      Dart_Handle err = DartUtils::NewDartOSError();
-      if (Dart_IsError(err)) Dart_PropagateError(err);
-      Dart_SetReturnValue(args, err);
+      Dart_SetReturnValue(args, DartUtils::NewDartOSError());
     } else {
       Dart_SetReturnValue(args, Dart_NewBoolean(result == File::kIdentical));
     }
   } else  {
     Dart_Handle err = DartUtils::NewDartArgumentError(
         "Non-string argument to FileSystemEntity.identical");
-    if (Dart_IsError(err)) Dart_PropagateError(err);
     Dart_SetReturnValue(args, err);
   }
 }
 
 
 static int64_t CObjectInt32OrInt64ToInt64(CObject* cobject) {
   ASSERT(cobject->IsInt32OrInt64());
   int64_t result;
   if (cobject->IsInt32()) {
     CObjectInt32 value(cobject);
@@ skipping 574 matching lines @@
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 }  // namespace bin
 }  // namespace dart