Use std::error_code instead of llvm::error_code.

The idea of this patch is to turn llvm/Support/system_error.h into a
transitional header that just brings in the erorr_code api to the llvm
namespace. I will remove it shortly afterwards.

The cases where the general idea needed some tweaking:

* std::errc is a namespace in msvc, so we cannot use "using std::errc". I could
add an #ifdef, but there were not that many uses, so I just added std:: to
them in this patch.

* Template specialization had to be moved to the std namespace in this
patch set already.

* The msvc implementation of default_error_condition doesn't seem to
provide the same transformations as we need. Not too surprising since
the standard doesn't actually say what "equivalent" means. I fixed the
problem by keeping our old mapping and using it at error_code
construction time.

Despite these shortcomings I think this is still a good thing. Some reasons:

* The different implementations of system_error might improve over time.
* It removes 925 lines of code from llvm already.
* It removes 6313 bytes from the text segment of the clang binary when
it is built with gcc and 2816 bytes when building with clang and
libstdc++.

llvm-svn: 210687

1 files changed, 115 insertions, 0 deletions

diff --git a/llvm/lib/Support/WindowsError.cpp b/llvm/lib/Support/WindowsError.cpp
new file mode 100644
index 00000000000..59c575ff9e2
--- /dev/null
+++ b/llvm/lib/Support/WindowsError.cpp
@@ -0,0 +1,115 @@
+//===-- WindowsError.cpp - Support for mapping windows errors to posix-----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements a mapping from windows errors to posix ones.
+//  The standard doesn't define what the equivalence is from system
+//  errors to generic ones. The one implemented in msvc is too conservative
+//  for llvm, so we do an extra mapping when constructing an error_code
+//  from an windows error. This allows the rest of llvm to simple checks
+//  like "EC == std::errc::file_exists" and have it work on both posix and
+//  windows.
+//
+//===----------------------------------------------------------------------===//
+
+#ifdef _MSC_VER
+
+#include <winerror.h>
+
+#include "llvm/Support/WindowsError.h"
+
+// I'd rather not double the line count of the following.
+#define MAP_ERR_TO_COND(x, y)                                                  \
+  case x:                                                                      \
+    return std::make_error_code(std::errc::y)
+
+std::error_code llvm::mapWindowsError(unsigned EV) {
+  switch (EV) {
+    MAP_ERR_TO_COND(ERROR_ACCESS_DENIED, permission_denied);
+    MAP_ERR_TO_COND(ERROR_ALREADY_EXISTS, file_exists);
+    MAP_ERR_TO_COND(ERROR_BAD_UNIT, no_such_device);
+    MAP_ERR_TO_COND(ERROR_BUFFER_OVERFLOW, filename_too_long);
+    MAP_ERR_TO_COND(ERROR_BUSY, device_or_resource_busy);
+    MAP_ERR_TO_COND(ERROR_BUSY_DRIVE, device_or_resource_busy);
+    MAP_ERR_TO_COND(ERROR_CANNOT_MAKE, permission_denied);
+    MAP_ERR_TO_COND(ERROR_CANTOPEN, io_error);
+    MAP_ERR_TO_COND(ERROR_CANTREAD, io_error);
+    MAP_ERR_TO_COND(ERROR_CANTWRITE, io_error);
+    MAP_ERR_TO_COND(ERROR_CURRENT_DIRECTORY, permission_denied);
+    MAP_ERR_TO_COND(ERROR_DEV_NOT_EXIST, no_such_device);
+    MAP_ERR_TO_COND(ERROR_DEVICE_IN_USE, device_or_resource_busy);
+    MAP_ERR_TO_COND(ERROR_DIR_NOT_EMPTY, directory_not_empty);
+    MAP_ERR_TO_COND(ERROR_DIRECTORY, invalid_argument);
+    MAP_ERR_TO_COND(ERROR_DISK_FULL, no_space_on_device);
+    MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists);
+    MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory);
+    MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device);
+    MAP_ERR_TO_COND(ERROR_HANDLE_EOF, value_too_large);
+    MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied);
+    MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device);
+    MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported);
+    MAP_ERR_TO_COND(ERROR_INVALID_HANDLE, invalid_argument);
+    MAP_ERR_TO_COND(ERROR_INVALID_NAME, invalid_argument);
+    MAP_ERR_TO_COND(ERROR_LOCK_VIOLATION, no_lock_available);
+    MAP_ERR_TO_COND(ERROR_LOCKED, no_lock_available);
+    MAP_ERR_TO_COND(ERROR_NEGATIVE_SEEK, invalid_argument);
+    MAP_ERR_TO_COND(ERROR_NOACCESS, permission_denied);
+    MAP_ERR_TO_COND(ERROR_NOT_ENOUGH_MEMORY, not_enough_memory);
+    MAP_ERR_TO_COND(ERROR_NOT_READY, resource_unavailable_try_again);
+    MAP_ERR_TO_COND(ERROR_NOT_SAME_DEVICE, cross_device_link);
+    MAP_ERR_TO_COND(ERROR_OPEN_FAILED, io_error);
+    MAP_ERR_TO_COND(ERROR_OPEN_FILES, device_or_resource_busy);
+    MAP_ERR_TO_COND(ERROR_OPERATION_ABORTED, operation_canceled);
+    MAP_ERR_TO_COND(ERROR_OUTOFMEMORY, not_enough_memory);
+    MAP_ERR_TO_COND(ERROR_PATH_NOT_FOUND, no_such_file_or_directory);
+    MAP_ERR_TO_COND(ERROR_BAD_NETPATH, no_such_file_or_directory);
+    MAP_ERR_TO_COND(ERROR_READ_FAULT, io_error);
+    MAP_ERR_TO_COND(ERROR_RETRY, resource_unavailable_try_again);
+    MAP_ERR_TO_COND(ERROR_SEEK, io_error);
+    MAP_ERR_TO_COND(ERROR_SHARING_VIOLATION, permission_denied);
+    MAP_ERR_TO_COND(ERROR_TOO_MANY_OPEN_FILES, too_many_files_open);
+    MAP_ERR_TO_COND(ERROR_WRITE_FAULT, io_error);
+    MAP_ERR_TO_COND(ERROR_WRITE_PROTECT, permission_denied);
+    MAP_ERR_TO_COND(ERROR_SEM_TIMEOUT, timed_out);
+    MAP_ERR_TO_COND(WSAEACCES, permission_denied);
+    MAP_ERR_TO_COND(WSAEADDRINUSE, address_in_use);
+    MAP_ERR_TO_COND(WSAEADDRNOTAVAIL, address_not_available);
+    MAP_ERR_TO_COND(WSAEAFNOSUPPORT, address_family_not_supported);
+    MAP_ERR_TO_COND(WSAEALREADY, connection_already_in_progress);
+    MAP_ERR_TO_COND(WSAEBADF, bad_file_descriptor);
+    MAP_ERR_TO_COND(WSAECONNABORTED, connection_aborted);
+    MAP_ERR_TO_COND(WSAECONNREFUSED, connection_refused);
+    MAP_ERR_TO_COND(WSAECONNRESET, connection_reset);
+    MAP_ERR_TO_COND(WSAEDESTADDRREQ, destination_address_required);
+    MAP_ERR_TO_COND(WSAEFAULT, bad_address);
+    MAP_ERR_TO_COND(WSAEHOSTUNREACH, host_unreachable);
+    MAP_ERR_TO_COND(WSAEINPROGRESS, operation_in_progress);
+    MAP_ERR_TO_COND(WSAEINTR, interrupted);
+    MAP_ERR_TO_COND(WSAEINVAL, invalid_argument);
+    MAP_ERR_TO_COND(WSAEISCONN, already_connected);
+    MAP_ERR_TO_COND(WSAEMFILE, too_many_files_open);
+    MAP_ERR_TO_COND(WSAEMSGSIZE, message_size);
+    MAP_ERR_TO_COND(WSAENAMETOOLONG, filename_too_long);
+    MAP_ERR_TO_COND(WSAENETDOWN, network_down);
+    MAP_ERR_TO_COND(WSAENETRESET, network_reset);
+    MAP_ERR_TO_COND(WSAENETUNREACH, network_unreachable);
+    MAP_ERR_TO_COND(WSAENOBUFS, no_buffer_space);
+    MAP_ERR_TO_COND(WSAENOPROTOOPT, no_protocol_option);
+    MAP_ERR_TO_COND(WSAENOTCONN, not_connected);
+    MAP_ERR_TO_COND(WSAENOTSOCK, not_a_socket);
+    MAP_ERR_TO_COND(WSAEOPNOTSUPP, operation_not_supported);
+    MAP_ERR_TO_COND(WSAEPROTONOSUPPORT, protocol_not_supported);
+    MAP_ERR_TO_COND(WSAEPROTOTYPE, wrong_protocol_type);
+    MAP_ERR_TO_COND(WSAETIMEDOUT, timed_out);
+    MAP_ERR_TO_COND(WSAEWOULDBLOCK, operation_would_block);
+  default:
+    return std::error_code(EV, std::system_category());
+  }
+}
+
+#endif