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

1 files changed, 3 insertions, 3 deletions

diff --git a/tools/llvm-ar/llvm-ar.cpp b/tools/llvm-ar/llvm-ar.cpp
index ea85d5d3c9..77914c5792 100644
--- a/tools/llvm-ar/llvm-ar.cpp
+++ b/tools/llvm-ar/llvm-ar.cpp
@@ -453,7 +453,7 @@ int NewArchiveIterator::getFD() const {
   // Linux cannot open directories with open(2), although
   // cygwin and *bsd can.
   if (NewStatus.type() == sys::fs::file_type::directory_file)
-    failIfError(make_error_code(errc::is_a_directory), NewFilename);
+    failIfError(make_error_code(std::errc::is_a_directory), NewFilename);
 
   return NewFD;
 }
@@ -939,7 +939,7 @@ static int performOperation(ArchiveOperation Operation) {
   // Create or open the archive object.
   std::unique_ptr<MemoryBuffer> Buf;
   error_code EC = MemoryBuffer::getFile(ArchiveName, Buf, -1, false);
-  if (EC && EC != llvm::errc::no_such_file_or_directory) {
+  if (EC && EC != std::errc::no_such_file_or_directory) {
     errs() << ToolName << ": error opening '" << ArchiveName
            << "': " << EC.message() << "!\n";
     return 1;
@@ -957,7 +957,7 @@ static int performOperation(ArchiveOperation Operation) {
     return 0;
   }
 
-  assert(EC == llvm::errc::no_such_file_or_directory);
+  assert(EC == std::errc::no_such_file_or_directory);
 
   if (!shouldCreateArchive(Operation)) {
     failIfError(EC, Twine("error loading '") + ArchiveName + "'");