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++.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210687 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 6 insertions, 40 deletions

diff --git a/lib/Support/Unix/Path.inc b/lib/Support/Unix/Path.inc
index 11ea10e120..ef291db52d 100644
--- a/lib/Support/Unix/Path.inc
+++ b/lib/Support/Unix/Path.inc
@@ -317,7 +317,7 @@ error_code remove(const Twine &path, bool IgnoreNonExisting) {
   // effectively prevents LLVM from erasing things like /dev/null, any block
   // special file, or other things that aren't "regular" files.
   if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode) && !S_ISLNK(buf.st_mode))
-    return make_error_code(errc::operation_not_permitted);
+    return make_error_code(std::errc::operation_not_permitted);
 
   if (::remove(p.begin()) == -1) {
     if (errno != ENOENT || !IgnoreNonExisting)
@@ -402,7 +402,7 @@ static error_code fillStatus(int StatRet, const struct stat &Status,
                              file_status &Result) {
   if (StatRet != 0) {
     error_code ec(errno, generic_category());
-    if (ec == errc::no_such_file_or_directory)
+    if (ec == std::errc::no_such_file_or_directory)
       Result = file_status(file_type::file_not_found);
     else
       Result = file_status(file_type::status_error);
@@ -466,7 +466,7 @@ error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
   return error_code();
 #else
 #warning Missing futimes() and futimens()
-  return make_error_code(errc::not_supported);
+  return make_error_code(std::errc::not_supported);
 #endif
 }
 
@@ -510,7 +510,7 @@ mapped_file_region::mapped_file_region(const Twine &path,
   , Mapping() {
   // Make sure that the requested size fits within SIZE_T.
   if (length > std::numeric_limits<size_t>::max()) {
-    ec = make_error_code(errc::invalid_argument);
+    ec = make_error_code(std::errc::invalid_argument);
     return;
   }
 
@@ -539,7 +539,7 @@ mapped_file_region::mapped_file_region(int fd,
   , Mapping() {
   // Make sure that the requested size fits within SIZE_T.
   if (length > std::numeric_limits<size_t>::max()) {
-    ec = make_error_code(errc::invalid_argument);
+    ec = make_error_code(std::errc::invalid_argument);
     return;
   }
 
@@ -645,7 +645,7 @@ error_code get_magic(const Twine &path, uint32_t len,
     if (std::feof(file) != 0) {
       std::fclose(file);
       result.set_size(size);
-      return make_error_code(errc::value_too_large);
+      return make_error_code(std::errc::value_too_large);
     }
   }
   std::fclose(file);
diff --git a/lib/Support/Unix/system_error.inc b/lib/Support/Unix/system_error.inc
deleted file mode 100644
index 681e919edb..0000000000
--- a/lib/Support/Unix/system_error.inc
+++ /dev/null
@@ -1,34 +0,0 @@
-//===- llvm/Support/Unix/system_error.inc - Unix error_code ------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file provides the Unix specific implementation of the error_code
-// and error_condition classes.
-//
-//===----------------------------------------------------------------------===//
-
-//===----------------------------------------------------------------------===//
-//=== WARNING: Implementation here must contain only generic UNIX code that
-//===          is guaranteed to work on *all* UNIX variants.
-//===----------------------------------------------------------------------===//
-
-using namespace llvm;
-
-std::string
-_system_error_category::message(int ev) const {
-  return _do_message::message(ev);
-}
-
-error_condition
-_system_error_category::default_error_condition(int ev) const {
-#ifdef ELAST
-  if (ev > ELAST)
-    return error_condition(ev, system_category());
-#endif  // ELAST
-  return error_condition(ev, generic_category());
-}