Merge qt_error_string and QSystemError

This removes a lot of duplicated code that existed in both qglobal.cpp
and qsystemerror.cpp, including the hack to get the correct strerror_r
signature.

This removes the incorrect use of EACCES, EMFILE, ENOENT, and ENOSPC
from qt_error_string on Windows. qt_error_string is supposed to be used
only with Win32 error codes from GetLastError(), despite there being a
lot of uses in cross-platform and even Windows-specific code that pass
errno constants.

It may or may not work: that depends on whether the constants happen to
match. ENOENT matches ERROR_FILE_NOT_FOUND and one could argue that
ENOSPC matching ERROR_OUT_OF_PAPER is acceptable, but EMFILE isn't the
same as ERROR_BAD_LENGTH nor is EACCES, ERROR_INVALID_DATA.

Change-Id: I1eba2b016de74620bfc8fffd14cccb7f77f4b510
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/src/corelib/kernel/qsystemerror_p.h b/src/corelib/kernel/qsystemerror_p.h
index 440b763149..1d8c253f53 100644
--- a/src/corelib/kernel/qsystemerror_p.h
+++ b/src/corelib/kernel/qsystemerror_p.h
@@ -69,10 +69,16 @@ public:
     inline QSystemError(int error, ErrorScope scope);
     inline QSystemError();
 
-    QString toString() const;
+    inline QString toString() const;
     inline ErrorScope scope() const;
     inline int error() const;
 
+    static QString string(ErrorScope errorScope, int errorCode);
+    static QString stdString(int errorCode = -1);
+#ifdef Q_OS_WIN
+    static QString windowsString(int errorCode = -1);
+#endif
+
     //data members
     int errorCode;
     ErrorScope errorScope;
@@ -90,6 +96,11 @@ QSystemError::QSystemError()
 
 }
 
+QString QSystemError::toString() const
+{
+    return string(errorScope, errorCode);
+}
+
 QSystemError::ErrorScope QSystemError::scope() const
 {
     return errorScope;
@@ -100,7 +111,6 @@ int QSystemError::error() const
     return errorCode;
 }
 
-
 QT_END_NAMESPACE
 
 #endif // QSYSTEMERROR_P_H