Move posix_fd_file, etc. into their own file

I want to use posix_fd_file outside of file.cpp. Move the posix_fd_file
class (and the related windows_handle_file class) into its own module so
it can be reused.

This commit should not change behavior.

src/CMakeLists.txt

@@ -35,6 +35,7 @@ quick_lint_js_add_library(
   assert.cpp
   char8.cpp
   error.cpp
+  file-handle.cpp
   file.cpp
   integer.cpp
   language.cpp

src/file-handle.cpp

@@ -0,0 +1,138 @@
+// quick-lint-js finds bugs in JavaScript programs.
+// Copyright (C) 2020  Matthew Glazar
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#include <cerrno>
+#include <cstddef>
+#include <cstdio>
+#include <cstring>
+#include <limits>
+#include <optional>
+#include <quick-lint-js/file-handle.h>
+#include <quick-lint-js/have.h>
+#include <quick-lint-js/narrow-cast.h>
+#include <string>
+#include <string_view>
+
+#if QLJS_HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#if QLJS_HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+
+#if QLJS_HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#if QLJS_HAVE_WINDOWS_H
+#include <Windows.h>
+#endif
+
+namespace quick_lint_js {
+#if QLJS_HAVE_WINDOWS_H
+windows_handle_file::windows_handle_file(HANDLE handle) noexcept
+    : handle_(handle) {}
+
+windows_handle_file::~windows_handle_file() {
+  if (!::CloseHandle(this->handle_)) {
+    std::fprintf(stderr, "error: failed to close file\n");
+  }
+}
+
+HANDLE windows_handle_file::get() noexcept { return this->handle_; }
+
+std::optional<int> windows_handle_file::read(void *buffer,
+                                             int buffer_size) noexcept {
+  DWORD read_size;
+  if (!::ReadFile(this->handle_, buffer, narrow_cast<DWORD>(buffer_size),
+                  &read_size,
+                  /*lpOverlapped=*/nullptr)) {
+    return std::nullopt;
+  }
+  return narrow_cast<int>(read_size);
+}
+
+std::string windows_handle_file::get_last_error_message() {
+  return windows_error_message(::GetLastError());
+}
+#endif
+
+#if QLJS_HAVE_UNISTD_H
+posix_fd_file::posix_fd_file(int fd) noexcept : fd_(fd) {}
+
+posix_fd_file::~posix_fd_file() {
+  int rc = ::close(this->fd_);
+  if (rc != 0) {
+    std::fprintf(stderr, "error: failed to close file: %s\n",
+                 std::strerror(errno));
+  }
+}
+
+int posix_fd_file::get() noexcept { return this->fd_; }
+
+std::optional<int> posix_fd_file::read(void *buffer, int buffer_size) noexcept {
+  ::ssize_t read_size =
+      ::read(this->fd_, buffer, narrow_cast<std::size_t>(buffer_size));
+  if (read_size == -1) {
+    return std::nullopt;
+  }
+  return narrow_cast<int>(read_size);
+}
+
+std::string posix_fd_file::get_last_error_message() {
+  return std::strerror(errno);
+}
+#endif
+
+#if QLJS_HAVE_WINDOWS_H
+namespace {
+std::string_view remove_suffix_if_present(std::string_view s,
+                                          std::string_view suffix) noexcept {
+  if (s.ends_with(suffix)) {
+    s.remove_suffix(suffix.size());
+  }
+  return s;
+}
+}
+
+std::string windows_error_message(DWORD error) {
+  // TODO(strager): Use FormatMessageW.
+  LPSTR get_last_error_message;
+  DWORD get_last_error_message_length = ::FormatMessageA(
+      /*dwFlags=*/FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
+          FORMAT_MESSAGE_IGNORE_INSERTS,
+      /*lpSource=*/nullptr,
+      /*dwMessageId=*/::GetLastError(),
+      /*dwLanguageId=*/0,
+      /*lpBuffer=*/reinterpret_cast<LPSTR>(&get_last_error_message),
+      /*nSize=*/(std::numeric_limits<DWORD>::max)(),
+      /*Arguments=*/nullptr);
+  if (get_last_error_message_length == 0) {
+    // FormatMessageA failed.
+    return "unknown error";
+  }
+
+  std::string_view message(
+      get_last_error_message,
+      narrow_cast<std::size_t>(get_last_error_message_length));
+  message = remove_suffix_if_present(message, "\r\n");
+  std::string message_copy(message);
+  static_cast<void>(::LocalFree(get_last_error_message));
+  return message_copy;
+}
+#endif
+}

src/file.cpp

@@ -19,16 +19,14 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
-#include <limits>
 #include <optional>
 #include <quick-lint-js/assert.h>
 #include <quick-lint-js/char8.h>
+#include <quick-lint-js/file-handle.h>
 #include <quick-lint-js/file.h>
 #include <quick-lint-js/have.h>
 #include <quick-lint-js/narrow-cast.h>
-#include <quick-lint-js/warning.h>
 #include <string>
-#include <string_view>
 
 #if QLJS_HAVE_FCNTL_H
 #include <fcntl.h>
@@ -38,10 +36,6 @@
 #include <sys/stat.h>
 #endif
 
-#if QLJS_HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-
 #if QLJS_HAVE_WINDOWS_H
 #include <Windows.h>
 #endif
@@ -70,77 +64,9 @@ read_file_result read_file_result::failure(const std::string &error) {
 
 namespace {
 #if defined(QLJS_FILE_WINDOWS)
-std::string windows_error_message(DWORD error);
-#endif
-
-#if defined(QLJS_FILE_WINDOWS)
-class windows_handle_file {
- public:
-  explicit windows_handle_file(HANDLE handle) noexcept : handle_(handle) {}
-
-  windows_handle_file(const windows_handle_file &) = delete;
-  windows_handle_file &operator=(const windows_handle_file &) = delete;
-
-  ~windows_handle_file() {
-    if (!::CloseHandle(this->handle_)) {
-      std::fprintf(stderr, "error: failed to close file\n");
-    }
-  }
-
-  HANDLE get() noexcept { return this->handle_; }
-
-  std::optional<int> read(void *buffer, int buffer_size) noexcept {
-    DWORD read_size;
-    if (!::ReadFile(this->handle_, buffer, narrow_cast<DWORD>(buffer_size),
-                    &read_size,
-                    /*lpOverlapped=*/nullptr)) {
-      return std::nullopt;
-    }
-    return narrow_cast<int>(read_size);
-  }
-
-  static std::string get_last_error_message() {
-    return windows_error_message(::GetLastError());
-  }
-
- private:
-  HANDLE handle_;
-};
 using platform_file = windows_handle_file;
 #endif
-
 #if defined(QLJS_FILE_POSIX)
-class posix_fd_file {
- public:
-  explicit posix_fd_file(int fd) noexcept : fd_(fd) {}
-
-  posix_fd_file(const posix_fd_file &) = delete;
-  posix_fd_file &operator=(const posix_fd_file &) = delete;
-
-  ~posix_fd_file() {
-    int rc = ::close(this->fd_);
-    if (rc != 0) {
-      std::fprintf(stderr, "error: failed to close file: %s\n",
-                   std::strerror(errno));
-    }
-  }
-
-  int get() noexcept { return this->fd_; }
-
-  std::optional<int> read(void *buffer, int buffer_size) noexcept {
-    ::ssize_t read_size =
-        ::read(this->fd_, buffer, narrow_cast<std::size_t>(buffer_size));
-    if (read_size == -1) {
-      return std::nullopt;
-    }
-    return narrow_cast<int>(read_size);
-  }
-
-  static std::string get_last_error_message() { return std::strerror(errno); }
-
- private:
-  int fd_;
-};
 using platform_file = posix_fd_file;
 #endif
 
@@ -259,42 +185,4 @@ read_file_result read_file(const char *path) {
   return read_file(path, file);
 }
 #endif
-
-namespace {
-#if defined(QLJS_FILE_WINDOWS)
-std::string_view remove_suffix_if_present(std::string_view s,
-                                          std::string_view suffix) noexcept {
-  if (s.ends_with(suffix)) {
-    s.remove_suffix(suffix.size());
-  }
-  return s;
-}
-
-std::string windows_error_message(DWORD error) {
-  // TODO(strager): Use FormatMessageW.
-  LPSTR get_last_error_message;
-  DWORD get_last_error_message_length = ::FormatMessageA(
-      /*dwFlags=*/FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
-          FORMAT_MESSAGE_IGNORE_INSERTS,
-      /*lpSource=*/nullptr,
-      /*dwMessageId=*/::GetLastError(),
-      /*dwLanguageId=*/0,
-      /*lpBuffer=*/reinterpret_cast<LPSTR>(&get_last_error_message),
-      /*nSize=*/(std::numeric_limits<DWORD>::max)(),
-      /*Arguments=*/nullptr);
-  if (get_last_error_message_length == 0) {
-    // FormatMessageA failed.
-    return "unknown error";
-  }
-
-  std::string_view message(
-      get_last_error_message,
-      narrow_cast<std::size_t>(get_last_error_message_length));
-  message = remove_suffix_if_present(message, "\r\n");
-  std::string message_copy(message);
-  static_cast<void>(::LocalFree(get_last_error_message));
-  return message_copy;
-}
-#endif
-}
 }

src/include/quick-lint-js/file-handle.h

@@ -0,0 +1,71 @@
+// quick-lint-js finds bugs in JavaScript programs.
+// Copyright (C) 2020  Matthew Glazar
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#include <optional>
+#include <quick-lint-js/have.h>
+#include <string>
+
+#if QLJS_HAVE_WINDOWS_H
+#include <Windows.h>
+#endif
+
+namespace quick_lint_js {
+#if QLJS_HAVE_WINDOWS_H
+std::string windows_error_message(DWORD error);
+#endif
+
+#if QLJS_HAVE_WINDOWS_H
+class windows_handle_file {
+ public:
+  explicit windows_handle_file(HANDLE) noexcept;
+
+  windows_handle_file(const windows_handle_file &) = delete;
+  windows_handle_file &operator=(const windows_handle_file &) = delete;
+
+  ~windows_handle_file();
+
+  HANDLE get() noexcept;
+
+  std::optional<int> read(void *buffer, int buffer_size) noexcept;
+
+  static std::string get_last_error_message();
+
+ private:
+  HANDLE handle_;
+};
+#endif
+
+#if QLJS_HAVE_UNISTD_H
+class posix_fd_file {
+ public:
+  explicit posix_fd_file(int fd) noexcept;
+
+  posix_fd_file(const posix_fd_file &) = delete;
+  posix_fd_file &operator=(const posix_fd_file &) = delete;
+
+  ~posix_fd_file();
+
+  int get() noexcept;
+
+  std::optional<int> read(void *buffer, int buffer_size) noexcept;
+
+  static std::string get_last_error_message();
+
+ private:
+  int fd_;
+};
+#endif
+}

src/include/quick-lint-js/narrow-cast.h

@@ -30,13 +30,13 @@ constexpr bool can_narrow_cast([[maybe_unused]] In x) noexcept {
   if constexpr (std::is_same_v<In, Out>) {
     return true;
   } else if constexpr (std::is_signed_v<In> && std::is_signed_v<Out>) {
-    return out_limits::lowest() <= x && x <= out_limits::max();
+    return out_limits::lowest() <= x && x <= (out_limits::max)();
   } else if constexpr (std::is_signed_v<In> && !std::is_signed_v<Out>) {
-    return 0 <= x && static_cast<unsigned_in>(x) <= out_limits::max();
+    return 0 <= x && static_cast<unsigned_in>(x) <= (out_limits::max)();
   } else if constexpr (!std::is_signed_v<In> && std::is_signed_v<Out>) {
-    return x <= unsigned_out{out_limits::max()};
+    return x <= unsigned_out{(out_limits::max)()};
   } else if constexpr (!std::is_signed_v<In> && !std::is_signed_v<Out>) {
-    return x <= out_limits::max();
+    return x <= (out_limits::max)();
   }
 }