| // Copyright 2016 The Bazel Authors. All rights reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include <jni.h> |
| #include <windows.h> |
| |
| #include <string> |
| |
| #include "src/main/native/windows_error_handling.h" |
| |
| // Keep in sync with j.c.g.devtools.build.lib.windows.WindowsFileOperations |
| enum { |
| IS_JUNCTION_YES = 0, |
| IS_JUNCTION_NO = 1, |
| IS_JUNCTION_ERROR = 2, |
| }; |
| |
| // Determines whether `path` is a junction point or directory symlink. |
| // |
| // To read about differences between junction points and directory symlinks, |
| // see http://superuser.com/a/343079. |
| // |
| // Returns: |
| // - IS_JUNCTION_YES, if `path` exists and is either a directory junction or a |
| // directory symlink |
| // - IS_JUNCTION_NO, if `path` exists but is neither a directory junction nor a |
| // directory symlink; also when `path` is a symlink to a directory but it was |
| // created using "mklink" instead of "mklink /d", as such symlinks don't |
| // behave the same way as directories (e.g. they can't be listed) |
| // - IS_JUNCTION_ERROR, if `path` doesn't exist or some error occurred |
| int IsJunctionOrDirectorySymlink(const char* path) { |
| DWORD attrs = GetFileAttributesA(path); |
| if (attrs == INVALID_FILE_ATTRIBUTES) { |
| return IS_JUNCTION_ERROR; |
| } else { |
| if ((attrs & FILE_ATTRIBUTE_DIRECTORY) && |
| (attrs & FILE_ATTRIBUTE_REPARSE_POINT)) { |
| return IS_JUNCTION_YES; |
| } else { |
| return IS_JUNCTION_NO; |
| } |
| } |
| } |
| |
| extern "C" JNIEXPORT jint JNICALL |
| Java_com_google_devtools_build_lib_windows_WindowsFileOperations_nativeIsJunction( |
| JNIEnv* env, jclass clazz, jstring path, jobjectArray error_msg_holder) { |
| const char* path_cstr = env->GetStringUTFChars(path, NULL); |
| bool report_error = |
| error_msg_holder != NULL && env->GetArrayLength(error_msg_holder) > 0; |
| int result = IsJunctionOrDirectorySymlink(path_cstr); |
| if (result == IS_JUNCTION_ERROR && report_error) { |
| std::string error_str = |
| GetLastErrorString(std::string("GetFileAttributesA(") + |
| std::string(path_cstr) + std::string(")")); |
| jstring error_msg = env->NewStringUTF(error_str.c_str()); |
| env->SetObjectArrayElement(error_msg_holder, 0, error_msg); |
| } |
| |
| env->ReleaseStringUTFChars(path, path_cstr); |
| return result; |
| } |