Merge pull request #5986 from Sonicadvance1/259

FEXCore: Adds a utility function for deleting a directory

FEXCore/Source/CMakeLists.txt

@@ -4,6 +4,7 @@ set(FEXCORE_BASE_SRCS
   Interface/Config/Config.cpp
   Utils/Allocator.cpp
   Utils/FileLoading.cpp
+  Utils/FileUtils.cpp
   Utils/ForcedAssert.cpp
   Utils/LogManager.cpp
   Utils/SpinWaitLock.cpp

FEXCore/Source/Utils/FileUtils.cpp

@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: MIT
+#include <FEXCore/fextl/fmt.h>
+#include <FEXCore/fextl/string.h>
+#include <FEXCore/Utils/CompilerDefs.h>
+#include <FEXCore/Utils/LogManager.h>
+
+#ifndef _WIN32
+#include <dirent.h>
+#include <fcntl.h>
+#include <unistd.h>
+#endif
+
+namespace FEXCore::FileUtils {
+#ifndef _WIN32
+static inline bool unlinkat(int fd, const char* path, bool dir) {
+  if (::unlinkat(fd, path, dir ? AT_REMOVEDIR : 0) == -1) {
+    return errno == ENOENT;
+  }
+  return true;
+}
+
+static bool RecursiveRemoveDirectory(int parent_fd, const char* Directory) {
+  // Don't follow symlinks and ensure it closes on exec.
+  constexpr int DIR_FLAGS = O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC;
+  int dir_fd = ::openat(parent_fd, Directory, DIR_FLAGS);
+
+  if (dir_fd == -1) {
+    if (errno == ENOENT) {
+      // Probably raced something. Non-error.
+      return true;
+    }
+  }
+
+  // Walk the directory listing.
+  bool Result = true;
+  // Four pages arbitrary chosen to be a balance between NFS wanting to return data in page-size granules and
+  // local filesystems returning arbitrary sizes.
+  size_t dirent_size = 4096 * 4;
+  uint8_t* dirent_buffer = reinterpret_cast<uint8_t*>(FEXCore::Allocator::malloc(dirent_size));
+
+  if (!dirent_buffer) {
+    // Ran out of memory?
+    Result = false;
+    goto end;
+  }
+
+  while (true) {
+    ssize_t read = getdents64(dir_fd, dirent_buffer, dirent_size);
+
+    if (read == -1) {
+      if (errno == EINVAL) {
+        // Buffer too small? Scale and try again.
+        dirent_size *= 2;
+        FEXCore::Allocator::free(dirent_buffer);
+        dirent_buffer = reinterpret_cast<uint8_t*>(FEXCore::Allocator::malloc(dirent_size));
+        if (!dirent_buffer) {
+          // Ran out of memory?
+          Result = false;
+          goto end;
+        }
+
+        continue;
+      }
+
+      // Anything else just exit.
+      Result = false;
+      goto end;
+    }
+
+    if (read == 0) {
+      // Done.
+      break;
+    }
+
+    for (size_t dirent_offset = 0; dirent_offset < read;) {
+      auto path_dirent = reinterpret_cast<const struct dirent*>(dirent_buffer + dirent_offset);
+      std::string_view path_name_view = path_dirent->d_name;
+
+      if (path_name_view == "." || path_name_view == "..") {
+        // Skip these two special files.
+        dirent_offset += path_dirent->d_reclen;
+        continue;
+      }
+
+      if (path_dirent->d_type == DT_DIR) {
+        // Recurse directories as we find them and remove them.
+        if (!RecursiveRemoveDirectory(dir_fd, path_dirent->d_name)) {
+          Result = false;
+          goto end;
+        }
+      }
+
+      // Remove anything possible.
+      if (!unlinkat(dir_fd, path_dirent->d_name, path_dirent->d_type == DT_DIR)) {
+        // Couldn't unlink the file for some reason.
+        LogMan::Msg::IFmt("Failed to remove file: {}", path_name_view);
+        Result = false;
+        goto end;
+      }
+
+      // dirent is a VLA so we need to increment by reported size.
+      dirent_offset += path_dirent->d_reclen;
+    }
+  }
+
+end:
+  if (dirent_buffer) {
+    FEXCore::Allocator::free(dirent_buffer);
+  }
+
+  close(dir_fd);
+  return Result;
+}
+
+FEX_DEFAULT_VISIBILITY bool RecursiveRemoveDirectory(const fextl::string& Directory) {
+  return RecursiveRemoveDirectory(AT_FDCWD, Directory.c_str()) && unlinkat(AT_FDCWD, Directory.c_str(), true);
+}
+#else
+FEX_DEFAULT_VISIBILITY bool RecursiveRemoveDirectory(std::string_view Directory) {
+  std::error_code ec;
+  return std::filesystem::remove_all(Directory, ec) != ~0ULL;
+}
+#endif
+} // namespace FEXCore::FileUtils

FEXCore/include/FEXCore/Utils/FileUtils.h

@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: MIT
+#pragma once
+#include <FEXCore/fextl/string.h>
+#include <FEXCore/Utils/CompilerDefs.h>
+
+namespace FEXCore::FileUtils {
+/**
+ * @brief Removes an entirely directory passed in. Including the path itself.
+ *
+ * @return True if the directory didn't exist or was deleted.
+ */
+FEX_DEFAULT_VISIBILITY bool RecursiveRemoveDirectory(const fextl::string& Directory);
+} // namespace FEXCore::FileUtils