1 files changed, 132 insertions, 0 deletions
diff --git a/lib/pure/includes/oserr.nim b/lib/pure/includes/oserr.nim
new file mode 100644
index 000000000..ef3f82628
--- /dev/null
+++ b/lib/pure/includes/oserr.nim
@@ -0,0 +1,132 @@
+## Include file that implements 'osErrorMsg' and friends. Do not import it!
+
+when not declared(ospaths):
+  {.error: "This is an include file for ospaths.nim!".}
+
+when not defined(nimscript):
+  var errno {.importc, header: "<errno.h>".}: cint
+
+  proc c_strerror(errnum: cint): cstring {.
+    importc: "strerror", header: "<string.h>".}
+
+proc osErrorMsg*(): string {.rtl, extern: "nos$1", deprecated.} =
+  ## Retrieves the operating system's error flag, ``errno``.
+  ## On Windows ``GetLastError`` is checked before ``errno``.
+  ## Returns "" if no error occurred.
+  ##
+  ## **Deprecated since version 0.9.4**: use the other ``osErrorMsg`` proc.
+
+  result = ""
+  when defined(Windows) and not defined(nimscript):
+    var err = getLastError()
+    if err != 0'i32:
+      when useWinUnicode:
+        var msgbuf: WideCString
+        if formatMessageW(0x00000100 or 0x00001000 or 0x00000200 or 0x000000FF,
+                          nil, err, 0, addr(msgbuf), 0, nil) != 0'i32:
+          result = $msgbuf
+          if msgbuf != nil: localFree(cast[pointer](msgbuf))
+      else:
+        var msgbuf: cstring
+        if formatMessageA(0x00000100 or 0x00001000 or 0x00000200 or 0x000000FF,
+                          nil, err, 0, addr(msgbuf), 0, nil) != 0'i32:
+          result = $msgbuf
+          if msgbuf != nil: localFree(msgbuf)
+  when not defined(nimscript):
+    if errno != 0'i32:
+      result = $c_strerror(errno)
+
+{.push warning[deprecated]: off.}
+proc raiseOSError*(msg: string = "") {.noinline, rtl, extern: "nos$1",
+                                       deprecated.} =
+  ## raises an OSError exception with the given message ``msg``.
+  ## If ``msg == ""``, the operating system's error flag
+  ## (``errno``) is converted to a readable error message. On Windows
+  ## ``GetLastError`` is checked before ``errno``.
+  ## If no error flag is set, the message ``unknown OS error`` is used.
+  ##
+  ## **Deprecated since version 0.9.4**: use the other ``raiseOSError`` proc.
+  if len(msg) == 0:
+    var m = osErrorMsg()
+    raise newException(OSError, if m.len > 0: m else: "unknown OS error")
+  else:
+    raise newException(OSError, msg)
+{.pop.}
+
+when not defined(nimfix):
+  {.deprecated: [osError: raiseOSError].}
+
+proc `==`*(err1, err2: OSErrorCode): bool {.borrow.}
+proc `$`*(err: OSErrorCode): string {.borrow.}
+
+proc osErrorMsg*(errorCode: OSErrorCode): string =
+  ## Converts an OS error code into a human readable string.
+  ##
+  ## The error code can be retrieved using the ``osLastError`` proc.
+  ##
+  ## If conversion fails, or ``errorCode`` is ``0`` then ``""`` will be
+  ## returned.
+  ##
+  ## On Windows, the ``-d:useWinAnsi`` compilation flag can be used to
+  ## make this procedure use the non-unicode Win API calls to retrieve the
+  ## message.
+  result = ""
+  when defined(nimscript):
+    discard
+  elif defined(Windows):
+    if errorCode != OSErrorCode(0'i32):
+      when useWinUnicode:
+        var msgbuf: WideCString
+        if formatMessageW(0x00000100 or 0x00001000 or 0x00000200,
+                        nil, errorCode.int32, 0, addr(msgbuf), 0, nil) != 0'i32:
+          result = $msgbuf
+          if msgbuf != nil: localFree(cast[pointer](msgbuf))
+      else:
+        var msgbuf: cstring
+        if formatMessageA(0x00000100 or 0x00001000 or 0x00000200,
+                        nil, errorCode.int32, 0, addr(msgbuf), 0, nil) != 0'i32:
+          result = $msgbuf
+          if msgbuf != nil: localFree(msgbuf)
+  else:
+    if errorCode != OSErrorCode(0'i32):
+      result = $c_strerror(errorCode.int32)
+
+proc raiseOSError*(errorCode: OSErrorCode; additionalInfo = "") {.noinline.} =
+  ## Raises an ``OSError`` exception. The ``errorCode`` will determine the
+  ## message, ``osErrorMsg`` will be used to get this message.
+  ##
+  ## The error code can be retrieved using the ``osLastError`` proc.
+  ##
+  ## If the error code is ``0`` or an error message could not be retrieved,
+  ## the message ``unknown OS error`` will be used.
+  var e: ref OSError; new(e)
+  e.errorCode = errorCode.int32
+  if additionalInfo.len == 0:
+    e.msg = osErrorMsg(errorCode)
+  else:
+    e.msg = osErrorMsg(errorCode) & "\nAdditional info: " & additionalInfo
+  if e.msg == "":
+    e.msg = "unknown OS error"
+  raise e
+
+{.push stackTrace:off.}
+proc osLastError*(): OSErrorCode =
+  ## Retrieves the last operating system error code.
+  ##
+  ## This procedure is useful in the event when an OS call fails. In that case
+  ## this procedure will return the error code describing the reason why the
+  ## OS call failed. The ``OSErrorMsg`` procedure can then be used to convert
+  ## this code into a string.
+  ##
+  ## **Warning**:
+  ## The behaviour of this procedure varies between Windows and POSIX systems.
+  ## On Windows some OS calls can reset the error code to ``0`` causing this
+  ## procedure to return ``0``. It is therefore advised to call this procedure
+  ## immediately after an OS call fails. On POSIX systems this is not a problem.
+  when defined(nimscript):
+    discard
+  elif defined(windows):
+    result = OSErrorCode(getLastError())
+  else:
+    result = OSErrorCode(errno)
+{.pop.}