This is the first step in adding sane error handling support to LLVMSystem.

The system API's will be shifted over to returning an error_code, and returning
other return values as out parameters to the function.

Code that needs to check error conditions will use the errc enum values which
are the same as the posix_errno defines (EBADF, E2BIG, etc...), and are
compatable with the error codes in WinError.h due to some magic in system_error.

An example would be:

if (error_code ec = KillEvil("Java")) { // error_code can be converted to bool.
  handle_error(ec);
}

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119360 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 121 insertions, 0 deletions

diff --git a/lib/System/system_error.cpp b/lib/System/system_error.cpp
new file mode 100644
index 0000000000..e7de85255e
--- /dev/null
+++ b/lib/System/system_error.cpp
@@ -0,0 +1,121 @@
+//===---------------------- system_error.cpp ------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This was lifted from libc++ and modified for C++03.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/System/system_error.h"
+#include "llvm/System/Errno.h"
+#include <string>
+#include <cstring>
+
+namespace llvm {
+
+// class error_category
+
+error_category::error_category() {
+}
+
+error_category::~error_category() {
+}
+
+error_condition
+error_category::default_error_condition(int ev) const {
+  return error_condition(ev, *this);
+}
+
+bool
+error_category::equivalent(int code, const error_condition& condition) const {
+  return default_error_condition(code) == condition;
+}
+
+bool
+error_category::equivalent(const error_code& code, int condition) const {
+  return *this == code.category() && code.value() == condition;
+}
+
+std::string
+_do_message::message(int ev) const {
+  return std::string(sys::StrError(ev));
+}
+
+class _generic_error_category : public _do_message {
+public:
+  virtual const char* name() const;
+  virtual std::string message(int ev) const;
+};
+
+const char*
+_generic_error_category::name() const {
+  return "generic";
+}
+
+std::string
+_generic_error_category::message(int ev) const {
+#ifdef ELAST
+  if (ev > ELAST)
+    return std::string("unspecified generic_category error");
+#endif  // ELAST
+  return _do_message::message(ev);
+}
+
+const error_category&
+generic_category() {
+  static _generic_error_category s;
+  return s;
+}
+
+class _system_error_category : public _do_message {
+public:
+  virtual const char* name() const;
+  virtual std::string message(int ev) const;
+  virtual error_condition default_error_condition(int ev) const;
+};
+
+const char*
+_system_error_category::name() const {
+  return "system";
+}
+
+// std::string _system_error_category::message(int ev) const {
+// Is in Platform/system_error.inc
+
+// error_condition _system_error_category::default_error_condition(int ev) const
+// Is in Platform/system_error.inc
+
+const error_category&
+system_category() {
+  static _system_error_category s;
+  return s;
+}
+
+// error_condition
+
+std::string
+error_condition::message() const {
+  return _cat_->message(_val_);
+}
+
+// error_code
+
+std::string
+error_code::message() const {
+  return _cat_->message(_val_);
+}
+
+} // end namespace llvm
+
+// Include the truly platform-specific parts of this class.
+#if defined(LLVM_ON_UNIX)
+#include "Unix/system_error.inc"
+#endif
+#if defined(LLVM_ON_WIN32)
+#include "Win32/system_error.inc"
+#endif