Fixes some memory leaks in //runtime/bin

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"
 #include "bin/utils.h"
 
 #include "include/dart_api.h"
 #include "include/dart_tools_api.h"
 
 namespace dart {
 namespace bin {
 
 static const int kMSPerSecond = 1000;
 
 // Are we capturing output from stdout for the VM service?
 static bool capture_stdout = false;
 
 // Are we capturing output from stderr for the VM service?
 static bool capture_stderr = false;
 
-
 void SetCaptureStdout(bool value) {
   capture_stdout = value;
 }
 
 
 void SetCaptureStderr(bool value) {
   capture_stderr = value;
 }
 
 
 bool ShouldCaptureStdout() {
   return capture_stdout;
 }
 
 
 bool ShouldCaptureStderr() {
   return capture_stderr;
 }
 
 
-
 // The file pointer has been passed into Dart as an intptr_t and it is safe
 // to pull it out of Dart as a 64-bit integer, cast it to an intptr_t and
 // from there to a File pointer.
 static File* GetFilePointer(Dart_Handle handle) {
   intptr_t value = DartUtils::GetIntptrValue(handle);
   return reinterpret_cast<File*>(value);
 }
 
 
 bool File::ReadFully(void* buffer, int64_t num_bytes) {
@@ skipping 17 matching lines @@
   while (remaining > 0) {
     int64_t bytes_written = Write(current_buffer, remaining);
     if (bytes_written < 0) {
       return false;
     }
     remaining -= bytes_written;  // Reduce the number of remaining bytes.
     current_buffer += bytes_written;  // Move the buffer forward.
   }
   if (capture_stdout || capture_stderr) {
     intptr_t fd = GetFD();
-    if (fd == STDOUT_FILENO && capture_stdout) {
+    if ((fd == STDOUT_FILENO) && capture_stdout) {
       Dart_ServiceSendDataEvent("Stdout", "WriteEvent",
                                 reinterpret_cast<const uint8_t*>(buffer),
                                 num_bytes);
-    } else if (fd == STDERR_FILENO && capture_stderr) {
+    } else if ((fd == STDERR_FILENO) && capture_stderr) {
       Dart_ServiceSendDataEvent("Stderr", "WriteEvent",
                                 reinterpret_cast<const uint8_t*>(buffer),
                                 num_bytes);
     }
   }
   return true;
 }
 
 
 File::FileOpenMode File::DartModeToFileMode(DartFileOpenMode mode) {
-  ASSERT(mode == File::kDartRead ||
-         mode == File::kDartWrite ||
-         mode == File::kDartAppend ||
-         mode == File::kDartWriteOnly ||
-         mode == File::kDartWriteOnlyAppend);
+  ASSERT((mode == File::kDartRead) ||
+         (mode == File::kDartWrite) ||
+         (mode == File::kDartAppend) ||
+         (mode == File::kDartWriteOnly) ||
+         (mode == File::kDartWriteOnlyAppend));
   if (mode == File::kDartWrite) {
     return File::kWriteTruncate;
   }
   if (mode == File::kDartAppend) {
     return File::kWrite;
   }
   if (mode == File::kDartWriteOnly) {
     return File::kWriteOnlyTruncate;
   }
   if (mode == File::kDartWriteOnlyAppend) {
     return File::kWriteOnly;
   }
   return File::kRead;
 }
 
 
 void FUNCTION_NAME(File_Open)(Dart_NativeArguments args) {
   const char* filename =
       DartUtils::GetStringValue(Dart_GetNativeArgument(args, 0));
   int64_t mode = DartUtils::GetIntegerValue(Dart_GetNativeArgument(args, 1));
   File::DartFileOpenMode dart_file_mode =
       static_cast<File::DartFileOpenMode>(mode);
   File::FileOpenMode file_mode = File::DartModeToFileMode(dart_file_mode);
   // 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);
+  file = File::ScopedOpen(filename, file_mode);
   if (file != NULL) {
     Dart_SetReturnValue(args,
                         Dart_NewInteger(reinterpret_cast<intptr_t>(file)));
   } else {
     Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   }
 }
 
 
 void FUNCTION_NAME(File_Exists)(Dart_NativeArguments args) {
@@ skipping 67 matching lines @@
     } 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);
+        if (Dart_IsError(io_lib)) {
+          Dart_PropagateError(io_lib);
+        }
         Dart_Handle array_view =
             Dart_Invoke(io_lib,
                         DartUtils::NewString("_makeUint8ListView"),
                         kNumArgs,
                         dart_args);
         Dart_SetReturnValue(args, array_view);
       } else {
         Dart_SetReturnValue(args, external_array);
       }
     }
@@ skipping 13 matching lines @@
   // 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);
+  if (Dart_IsError(result)) {
+    Dart_PropagateError(result);
+  }
   ASSERT(end <= array_len);
-  uint8_t* buffer = new uint8_t[length];
+  uint8_t* buffer = Dart_ScopeAllocate(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)) {
       Dart_SetReturnValue(args, result);
     } else {
       Dart_SetReturnValue(args, Dart_NewInteger(bytes_read));
     }
   } else {
     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);
 
   // Offset and length arguments are checked in Dart code to be
   // integers and have the property that (offset + length) <=
   // 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));
 
   // The buffer object passed in has to be an Int8List or Uint8List object.
   // Acquire a direct pointer to the data area of the buffer object.
   Dart_TypedData_Type type;
   intptr_t length = end - start;
   intptr_t buffer_len = 0;
   void* buffer = NULL;
   Dart_Handle result =
       Dart_TypedDataAcquireData(buffer_obj, &type, &buffer, &buffer_len);
-  if (Dart_IsError(result)) Dart_PropagateError(result);
+  if (Dart_IsError(result)) {
+    Dart_PropagateError(result);
+  }
 
   ASSERT(type == Dart_TypedData_kUint8 || type == Dart_TypedData_kInt8);
   ASSERT(end <= buffer_len);
   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 (Dart_IsError(result)) {
+    Dart_PropagateError(result);
+  }
 
   if (!success) {
     Dart_SetReturnValue(args, DartUtils::NewDartOSError());
   } else {
     Dart_SetReturnValue(args, Dart_Null());
   }
 }
 
 
 void FUNCTION_NAME(File_Position)(Dart_NativeArguments args) {
@@ skipping 140 matching lines @@
         "Non-string argument to Link.create");
     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);
+    const char* target = File::LinkTarget(name);
     if (target == NULL) {
       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");
     Dart_SetReturnValue(args, err);
   }
 }
 
 
 void FUNCTION_NAME(File_Delete)(Dart_NativeArguments args) {
@@ skipping 58 matching lines @@
     Dart_SetReturnValue(args, Dart_NewBoolean(result));
   } else {
     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);
+  const char* path = File::GetCanonicalPath(str);
   if (path != NULL) {
     Dart_SetReturnValue(args, DartUtils::NewString(path));
-    free(path);
   } else {
     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));
@@ skipping 31 matching lines @@
     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_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);
+      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);
+      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);
+      if (Dart_IsError(status)) {
+        Dart_PropagateError(status);
+      }
       Dart_SetReturnValue(args, returned_data);
     }
   } else {
     Dart_Handle err = DartUtils::NewDartArgumentError(
         "Non-string argument to FileSystemEntity.stat");
     Dart_SetReturnValue(args, err);
   }
 }
 
 
@@ skipping 32 matching lines @@
 }
 
 
 File* CObjectToFilePointer(CObject* cobject) {
   CObjectIntptr value(cobject);
   return reinterpret_cast<File*>(value.Value());
 }
 
 
 CObject* File::ExistsRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsString()) {
+  if ((request.Length() == 1) && request[0]->IsString()) {
     CObjectString filename(request[0]);
     bool result = File::Exists(filename.CString());
     return CObject::Bool(result);
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::CreateRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsString()) {
+  if ((request.Length() == 1) && request[0]->IsString()) {
     CObjectString filename(request[0]);
     bool result = File::Create(filename.CString());
     if (result) {
       return CObject::True();
     } else {
       return CObject::NewOSError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
+
 CObject* File::OpenRequest(const CObjectArray& request) {
   File* file = NULL;
-  if (request.Length() == 2 &&
+  if ((request.Length() == 2) &&
       request[0]->IsString() &&
       request[1]->IsInt32()) {
     CObjectString filename(request[0]);
     CObjectInt32 mode(request[1]);
     File::DartFileOpenMode dart_file_mode =
         static_cast<File::DartFileOpenMode>(mode.Value());
     File::FileOpenMode file_mode = File::DartModeToFileMode(dart_file_mode);
-    file = File::Open(filename.CString(), file_mode);
+    file = File::ScopedOpen(filename.CString(), file_mode);
     if (file != NULL) {
       return new CObjectIntptr(
           CObject::NewIntptr(reinterpret_cast<intptr_t>(file)));
     } else {
       return CObject::NewOSError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::DeleteRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsString()) {
+  if ((request.Length() == 1) && request[0]->IsString()) {
     CObjectString filename(request[0]);
     bool result = File::Delete(filename.CString());
     if (result) {
       return CObject::True();
     } else {
       return CObject::NewOSError();
     }
   }
   return CObject::False();
 }
 
 
 CObject* File::RenameRequest(const CObjectArray& request) {
-  if (request.Length() == 2 &&
+  if ((request.Length() == 2) &&
       request[0]->IsString() &&
       request[1]->IsString()) {
     CObjectString old_path(request[0]);
     CObjectString new_path(request[1]);
     bool completed = File::Rename(old_path.CString(), new_path.CString());
-    if (completed) return CObject::True();
+    if (completed) {
+      return CObject::True();
+    }
     return CObject::NewOSError();
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::CopyRequest(const CObjectArray& request) {
-  if (request.Length() == 2 &&
+  if ((request.Length() == 2) &&
       request[0]->IsString() &&
       request[1]->IsString()) {
     CObjectString old_path(request[0]);
     CObjectString new_path(request[1]);
     bool completed = File::Copy(old_path.CString(), new_path.CString());
-    if (completed) return CObject::True();
+    if (completed) {
+      return CObject::True();
+    }
     return CObject::NewOSError();
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::ResolveSymbolicLinksRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsString()) {
+  if ((request.Length() == 1) && request[0]->IsString()) {
     CObjectString filename(request[0]);
-    char* result = File::GetCanonicalPath(filename.CString());
+    const char* result = File::GetCanonicalPath(filename.CString());
     if (result != NULL) {
       CObject* path = new CObjectString(CObject::NewString(result));
-      free(result);
       return path;
     } else {
       return CObject::NewOSError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::CloseRequest(const CObjectArray& request) {
   intptr_t return_value = -1;
-  if (request.Length() == 1 && request[0]->IsIntptr()) {
+  if ((request.Length() == 1) && request[0]->IsIntptr()) {
     File* file = CObjectToFilePointer(request[0]);
     ASSERT(file != NULL);
     delete file;
     return_value = 0;
   }
   return new CObjectIntptr(CObject::NewIntptr(return_value));
 }
 
 
 CObject* File::PositionRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsIntptr()) {
+  if ((request.Length() == 1) && request[0]->IsIntptr()) {
     File* file = CObjectToFilePointer(request[0]);
     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();
 }
 
 
 CObject* File::SetPositionRequest(const CObjectArray& request) {
-  if (request.Length() == 2 &&
+  if ((request.Length() == 2) &&
       request[0]->IsIntptr() &&
       request[1]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[0]);
     ASSERT(file != NULL);
     if (!file->IsClosed()) {
       int64_t position = CObjectInt32OrInt64ToInt64(request[1]);
       if (file->SetPosition(position)) {
         return CObject::True();
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::TruncateRequest(const CObjectArray& request) {
-  if (request.Length() == 2 &&
+  if ((request.Length() == 2) &&
       request[0]->IsIntptr() &&
       request[1]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[0]);
     ASSERT(file != NULL);
     if (!file->IsClosed()) {
       int64_t length = CObjectInt32OrInt64ToInt64(request[1]);
       if (file->Truncate(length)) {
         return CObject::True();
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::LengthRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsIntptr()) {
+  if ((request.Length() == 1) && request[0]->IsIntptr()) {
     File* file = CObjectToFilePointer(request[0]);
     ASSERT(file != NULL);
     if (!file->IsClosed()) {
       int64_t return_value = file->Length();
       if (return_value >= 0) {
         return new CObjectInt64(CObject::NewInt64(return_value));
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::LengthFromPathRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsString()) {
+  if ((request.Length() == 1) && request[0]->IsString()) {
     CObjectString filepath(request[0]);
     int64_t return_value = File::LengthFromPath(filepath.CString());
     if (return_value >= 0) {
       return new CObjectInt64(CObject::NewInt64(return_value));
     } else {
       return CObject::NewOSError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::LastModifiedRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsString()) {
+  if ((request.Length() == 1) && request[0]->IsString()) {
     CObjectString filepath(request[0]);
     int64_t return_value = File::LastModified(filepath.CString());
     if (return_value >= 0) {
       return new CObjectIntptr(CObject::NewInt64(return_value * kMSPerSecond));
     } else {
       return CObject::NewOSError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::FlushRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsIntptr()) {
+  if ((request.Length() == 1) && request[0]->IsIntptr()) {
     File* file = CObjectToFilePointer(request[0]);
     ASSERT(file != NULL);
     if (!file->IsClosed()) {
       if (file->Flush()) {
         return CObject::True();
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::ReadByteRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsIntptr()) {
+  if ((request.Length() == 1) && request[0]->IsIntptr()) {
     File* file = CObjectToFilePointer(request[0]);
     ASSERT(file != NULL);
     if (!file->IsClosed()) {
       uint8_t buffer;
       int64_t 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();
 }
 
 
 CObject* File::WriteByteRequest(const CObjectArray& request) {
-  if (request.Length() == 2 &&
+  if ((request.Length() == 2) &&
       request[0]->IsIntptr() &&
       request[1]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[0]);
     ASSERT(file != NULL);
     if (!file->IsClosed()) {
       int64_t byte = CObjectInt32OrInt64ToInt64(request[1]);
       uint8_t buffer = static_cast<uint8_t>(byte & 0xff);
       bool success = file->WriteFully(reinterpret_cast<void*>(&buffer), 1);
       if (success) {
         return new CObjectInt64(CObject::NewInt64(1));
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::ReadRequest(const CObjectArray& request) {
-  if (request.Length() == 2 &&
+  if ((request.Length() == 2) &&
       request[0]->IsIntptr() &&
       request[1]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[0]);
     ASSERT(file != NULL);
     if (!file->IsClosed()) {
       int64_t length = CObjectInt32OrInt64ToInt64(request[1]);
       Dart_CObject* io_buffer = CObject::NewIOBuffer(length);
       ASSERT(io_buffer != NULL);
       uint8_t* data = io_buffer->value.as_external_typed_data.data;
       int64_t bytes_read = file->Read(data, length);
@@ skipping 11 matching lines @@
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::ReadIntoRequest(const CObjectArray& request) {
-  if (request.Length() == 2 &&
+  if ((request.Length() == 2) &&
       request[0]->IsIntptr() &&
       request[1]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[0]);
     ASSERT(file != NULL);
     if (!file->IsClosed()) {
       int64_t length = CObjectInt32OrInt64ToInt64(request[1]);
       Dart_CObject* io_buffer = CObject::NewIOBuffer(length);
       ASSERT(io_buffer != NULL);
       uint8_t* data = io_buffer->value.as_external_typed_data.data;
       int64_t bytes_read = file->Read(data, length);
@@ skipping 37 matching lines @@
       return 8;
     default:
       break;
   }
   UNREACHABLE();
   return -1;
 }
 
 
 CObject* File::WriteFromRequest(const CObjectArray& request) {
-  if (request.Length() == 4 &&
+  if ((request.Length() == 4) &&
       request[0]->IsIntptr() &&
       (request[1]->IsTypedData() || request[1]->IsArray()) &&
       request[2]->IsInt32OrInt64() &&
       request[3]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[0]);
     ASSERT(file != NULL);
     if (!file->IsClosed()) {
       int64_t start = CObjectInt32OrInt64ToInt64(request[2]);
       int64_t end = CObjectInt32OrInt64ToInt64(request[3]);
       int64_t length = end - start;
       uint8_t* buffer_start;
       if (request[1]->IsTypedData()) {
         CObjectTypedData typed_data(request[1]);
         start = start * SizeInBytes(typed_data.Type());
         length = length * SizeInBytes(typed_data.Type());
         buffer_start = typed_data.Buffer() + start;
       } else {
         CObjectArray array(request[1]);
-        buffer_start = new uint8_t[length];
+        buffer_start = Dart_ScopeAllocate(length);
         for (int i = 0; i < length; i++) {
           if (array[i + start]->IsInt32OrInt64()) {
             int64_t value = CObjectInt32OrInt64ToInt64(array[i + start]);
             buffer_start[i] = static_cast<uint8_t>(value & 0xFF);
           } else {
             // Unsupported type.
-            delete[] buffer_start;
             return CObject::IllegalArgumentError();
           }
         }
         start = 0;
       }
       bool success =
           file->WriteFully(reinterpret_cast<void*>(buffer_start), length);
-      if (!request[1]->IsTypedData()) {
-        delete[] buffer_start;
-      }
       if (success) {
         return new CObjectInt64(CObject::NewInt64(length));
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::CreateLinkRequest(const CObjectArray& request) {
-  if (request.Length() != 2 ||
+  if ((request.Length() != 2) ||
       !request[0]->IsString() ||
       !request[1]->IsString()) {
     return CObject::IllegalArgumentError();
   }
   CObjectString link_name(request[0]);
   CObjectString target_name(request[1]);
   if (File::CreateLink(link_name.CString(), target_name.CString())) {
     return CObject::True();
   } else {
     return CObject::NewOSError();
   }
 }
 
 
 CObject* File::DeleteLinkRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsString()) {
+  if ((request.Length() == 1) && request[0]->IsString()) {
     CObjectString link_path(request[0]);
     bool result = File::DeleteLink(link_path.CString());
     if (result) {
       return CObject::True();
     } else {
       return CObject::NewOSError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::RenameLinkRequest(const CObjectArray& request) {
-  if (request.Length() == 2 &&
+  if ((request.Length() == 2) &&
       request[0]->IsString() &&
       request[1]->IsString()) {
     CObjectString old_path(request[0]);
     CObjectString new_path(request[1]);
     bool completed = File::RenameLink(old_path.CString(), new_path.CString());
-    if (completed) return CObject::True();
+    if (completed) {
+      return CObject::True();
+    }
     return CObject::NewOSError();
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::LinkTargetRequest(const CObjectArray& request) {
-  if (request.Length() == 1 && request[0]->IsString()) {
+  if ((request.Length() == 1) && request[0]->IsString()) {
     CObjectString link_path(request[0]);
-    char* target = File::LinkTarget(link_path.CString());
+    const char* target = File::LinkTarget(link_path.CString());
     if (target != NULL) {
       CObject* result = new CObjectString(CObject::NewString(target));
-      free(target);
       return result;
     } else {
       return CObject::NewOSError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::TypeRequest(const CObjectArray& request) {
-  if (request.Length() == 2 &&
+  if ((request.Length() == 2) &&
       request[0]->IsString() &&
       request[1]->IsBool()) {
     CObjectString path(request[0]);
     CObjectBool follow_links(request[1]);
     File::Type type = File::GetType(path.CString(), follow_links.Value());
     return new CObjectInt32(CObject::NewInt32(type));
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::IdenticalRequest(const CObjectArray& request) {
-  if (request.Length() == 2 &&
+  if ((request.Length() == 2) &&
       request[0]->IsString() &&
       request[1]->IsString()) {
     CObjectString path1(request[0]);
     CObjectString path2(request[1]);
     File::Identical result = File::AreIdentical(path1.CString(),
                                                 path2.CString());
     if (result == File::kError) {
       return CObject::NewOSError();
     } else if (result == File::kIdentical) {
       return CObject::True();
     } else {
       return CObject::False();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::StatRequest(const CObjectArray& request) {
-  if (request.Length() == 1 &&
-      request[0]->IsString()) {
+  if ((request.Length() == 1) && request[0]->IsString()) {
     int64_t data[File::kStatSize];
     CObjectString path(request[0]);
     File::Stat(path.CString(), data);
     if (data[File::kType] == File::kDoesNotExist) {
       return CObject::NewOSError();
     }
     CObjectArray* result =
         new CObjectArray(CObject::NewArray(File::kStatSize));
     for (int i = 0; i < File::kStatSize; ++i) {
       result->SetAt(i, new CObjectInt64(CObject::NewInt64(data[i])));
     }
     CObjectArray* wrapper = new CObjectArray(CObject::NewArray(2));
     wrapper->SetAt(0, new CObjectInt32(CObject::NewInt32(CObject::kSuccess)));
     wrapper->SetAt(1, result);
     return wrapper;
   }
   return CObject::IllegalArgumentError();
 }
 
 
 CObject* File::LockRequest(const CObjectArray& request) {
-  if (request.Length() == 4 &&
+  if ((request.Length() == 4) &&
       request[0]->IsIntptr() &&
       request[1]->IsInt32OrInt64() &&
       request[2]->IsInt32OrInt64() &&
       request[3]->IsInt32OrInt64()) {
     File* file = CObjectToFilePointer(request[0]);
     ASSERT(file != NULL);
     if (!file->IsClosed()) {
       int64_t lock = CObjectInt32OrInt64ToInt64(request[1]);
       int64_t start = CObjectInt32OrInt64ToInt64(request[2]);
       int64_t end = CObjectInt32OrInt64ToInt64(request[3]);
       if (file->Lock(static_cast<File::LockType>(lock), start, end)) {
         return CObject::True();
       } else {
         return CObject::NewOSError();
       }
     } else {
       return CObject::FileClosedError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 }  // namespace bin
 }  // namespace dart