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, 5 insertions, 5 deletions

diff --git a/llvm/lib/Support/Path.cpp b/llvm/lib/Support/Path.cpp
index 76bee479847..a9ac88e5d39 100644
--- a/llvm/lib/Support/Path.cpp
+++ b/llvm/lib/Support/Path.cpp
@@ -204,7 +204,7 @@ retry_random_path:
     if (error_code EC =
             sys::fs::openFileForWrite(Twine(ResultPath.begin()), ResultFD,
                                       sys::fs::F_RW | sys::fs::F_Excl, Mode)) {
-      if (EC == errc::file_exists)
+      if (EC == std::errc::file_exists)
         goto retry_random_path;
       return EC;
     }
@@ -224,7 +224,7 @@ retry_random_path:
 
   case FS_Dir: {
     if (error_code EC = sys::fs::create_directory(ResultPath.begin(), false)) {
-      if (EC == errc::file_exists)
+      if (EC == std::errc::file_exists)
         goto retry_random_path;
       return EC;
     }
@@ -829,7 +829,7 @@ error_code create_directories(const Twine &Path, bool IgnoreExisting) {
   error_code EC = create_directory(P, IgnoreExisting);
   // If we succeeded, or had any error other than the parent not existing, just
   // return it.
-  if (EC != errc::no_such_file_or_directory)
+  if (EC != std::errc::no_such_file_or_directory)
     return EC;
 
   // We failed because of a no_such_file_or_directory, try to create the
@@ -896,7 +896,7 @@ error_code has_magic(const Twine &path, const Twine &magic, bool &result) {
   SmallString<32> Buffer;
 
   if (error_code ec = get_magic(path, Magic.size(), Buffer)) {
-    if (ec == errc::value_too_large) {
+    if (ec == std::errc::value_too_large) {
       // Magic.size() > file_size(Path).
       result = false;
       return error_code();
@@ -1043,7 +1043,7 @@ error_code has_magic(const Twine &path, const Twine &magic, bool &result) {
 error_code identify_magic(const Twine &path, file_magic &result) {
   SmallString<32> Magic;
   error_code ec = get_magic(path, Magic.capacity(), Magic);
-  if (ec && ec != errc::value_too_large)
+  if (ec && ec != std::errc::value_too_large)
     return ec;
 
   result = identify_magic(Magic);