Fix some mmap errors on POSIX

Author: BCSharp

Src/IronPython.Modules/mmap.cs

@@ -5,7 +5,6 @@
 #if FEATURE_MMAP
 
 using System;
-using System.ComponentModel;
 using System.Diagnostics;
 using System.Globalization;
 using System.IO;
@@ -205,12 +204,12 @@ public static class MmapModule {
 
         public static readonly string __doc__ = null;
 
-        private static string FormatError(int errorCode) {
-            return new Win32Exception(errorCode).Message;
-        }
-
-        private static Exception WindowsError(int code) {
-            return PythonExceptions.CreateThrowable(PythonExceptions.OSError, code, FormatError(code));
+        private static Exception WindowsError(int winerror) {
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows)) {
+                return PythonNT.GetWin32Error(winerror);
+            } else {
+                return PythonNT.GetOsError(PythonExceptions._OSError.WinErrorToErrno(winerror));
+            }
         }
 
         public static PythonType error => PythonExceptions.OSError;
@@ -234,7 +233,7 @@ public MmapUnix(CodeContext/*!*/ context, int fileno, long length, int flags = M
             private static MemoryMappedFileAccess ToMmapFileAccess(int flags, int prot, int access) {
                 if (access == ACCESS_DEFAULT) {
                     if ((flags & (MAP_PRIVATE | MAP_SHARED)) == 0) {
-                        throw PythonOps.OSError(PythonErrno.EINVAL, "Invalid argument");
+                        throw PythonNT.GetOsError(PythonErrno.EINVAL);
                     }
                     if ((prot & PROT_WRITE) != 0) {
                         prot |= PROT_READ;
@@ -356,7 +355,7 @@ public MmapDefault(CodeContext/*!*/ context, int fileno, long length, string tag
                         }
                         // otherwise leaves _file as null and _sourceStream as null
                     } else {
-                        throw PythonOps.OSError(PythonExceptions._OSError.ERROR_INVALID_BLOCK, "Bad file descriptor");
+                        throw PythonNT.GetOsError(PythonErrno.EBADF);
                     }
 
                     if (_file is null) {
@@ -414,7 +413,7 @@ void CheckFileAccessAndSize(Stream stream, bool isWindows) {
 
                     try {
                         if (!isValid) {
-                            throw PythonOps.OSError(PythonExceptions._OSError.ERROR_ACCESS_DENIED, "Invalid access mode");
+                            throw WindowsError(PythonExceptions._OSError.ERROR_ACCESS_DENIED);
                         }
 
                         if (!isWindows) {
@@ -802,13 +801,21 @@ public void resize(long newsize) {
                         throw PythonOps.TypeError("mmap can't resize a readonly or copy-on-write memory map.");
                     }
 
+                    if (newsize < 0) {
+                        throw PythonOps.ValueError("new size out of range");
+                    }
+
                     if (_handle is not null
                         && (RuntimeInformation.IsOSPlatform(OSPlatform.OSX) || RuntimeInformation.IsOSPlatform(OSPlatform.Linux))) {
                         // resize on Posix platforms
                         try {
                             if (_handle.IsInvalid) {
                                 throw PythonNT.GetOsError(PythonErrno.EBADF);
                             }
+                            if (newsize == 0) {
+                                // resizing to an empty mapped region is not allowed
+                                throw PythonNT.GetOsError(PythonErrno.EINVAL);
+                            }
                             _view.Flush();
                             _view.Dispose();
                             _file.Dispose();

Src/IronPython.Modules/nt.cs

@@ -2132,8 +2132,9 @@ private static Exception ToPythonException(Exception e, string? filename = null)
                 message = e.Message;
                 isWindowsError = true;
             } else if (e is UnauthorizedAccessException unauth) {
-                errorCode = PythonExceptions._OSError.ERROR_ACCESS_DENIED;
-                return PythonOps.OSError(errorCode, "Access is denied", filename, errorCode);
+                return RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ?
+                    GetWin32Error(PythonExceptions._OSError.ERROR_ACCESS_DENIED, filename) :
+                    GetOsError(PythonErrno.EACCES, filename);
             } else {
                 var ioe = e as IOException;
                 Exception? pe = IOExceptionToPythonException(ioe, error, filename);
@@ -2155,7 +2156,7 @@ private static Exception ToPythonException(Exception e, string? filename = null)
             }
 
             if (isWindowsError) {
-                return PythonOps.OSError(errorCode, message, filename, errorCode);
+                return PythonOps.OSError(PythonExceptions._OSError.WinErrorToErrno(errorCode), message, filename, errorCode);
             }
 
             return PythonOps.OSError(errorCode, message, filename);
@@ -2313,8 +2314,8 @@ private static Exception DirectoryExistsError(string? filename) {
         }
 
 
-        internal static Exception GetOsError(int error, string? filename = null, string? filename2 = null)
-            => PythonOps.OSError(error, strerror(error), filename, null, filename2);
+        internal static Exception GetOsError(int errno, string? filename = null, string? filename2 = null)
+            => PythonOps.OSError(errno, strerror(errno), filename, null, filename2);
 
 #if FEATURE_NATIVE || FEATURE_CTYPES
 
@@ -2338,9 +2339,9 @@ private static string GetWin32ErrorMessage(int errorCode) {
         }
 
         [SupportedOSPlatform("windows")]
-        private static Exception GetWin32Error(int error, string? filename = null, string? filename2 = null) {
-            var msg = GetWin32ErrorMessage(error);
-            return PythonOps.OSError(0, msg, filename, error, filename2);
+        internal static Exception GetWin32Error(int winerror, string? filename = null, string? filename2 = null) {
+            var msg = GetWin32ErrorMessage(winerror);
+            return PythonOps.OSError(0, msg, filename, winerror, filename2);
         }
 
 #endif

Src/IronPython.Modules/resource.cs

@@ -329,8 +329,7 @@ private static object LimitsArgError()
         => LightExceptions.Throw(PythonOps.ValueError("expected a tuple of 2 integers"));
 
     private static object GetPInvokeError() {
-        int errno = Marshal.GetLastWin32Error(); // despite its name, on Posix it retrieves errno set by the last p/Invoke call
-        return LightExceptions.Throw(PythonOps.OSError(errno, PythonNT.strerror(errno)));
+        return LightExceptions.Throw(PythonNT.GetLastUnixError());
     }
 
     private static object ToPythonInt(this ulong value)

Src/IronPython/Runtime/Exceptions/PythonExceptions.cs

@@ -167,14 +167,14 @@ public override void __init__(params object[] args) {
                     }
                     if (args.Length >= 4) {
                         winerror = args[3] ?? Undefined;
-                        if (winerror is int) {
-                            errno = WinErrorToErrno((int)winerror);
+                        if (winerror is int err) {
+                            errno = WinErrorToErrno(err);
                         }
                     }
                     if (args.Length >= 5) {
                         filename2 = args[4] ?? Undefined;
                     }
-                    args = new object[] { errno, strerror };
+                    args = [errno, strerror];
                 }
                 base.__init__(args);
             }