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, 1 insertions, 1 deletions

diff --git a/llvm/unittests/Transforms/DebugIR/DebugIR.cpp b/llvm/unittests/Transforms/DebugIR/DebugIR.cpp
index 49ea09f7c6d..5860e31b9d7 100644
--- a/llvm/unittests/Transforms/DebugIR/DebugIR.cpp
+++ b/llvm/unittests/Transforms/DebugIR/DebugIR.cpp
@@ -58,7 +58,7 @@ bool removeIfExists(StringRef Path) {
   // This is an approximation, on error we don't know in general if the file
   // existed or not.
   llvm::error_code EC = sys::fs::remove(Path, false);
-  return EC != llvm::errc::no_such_file_or_directory;
+  return EC != std::errc::no_such_file_or_directory;
 }
 
 char * current_dir() {