bpo-37705: Improve the implementation of winerror_to_errno() (GH-15623)

winerror_to_errno() is no longer automatically generated.
Do not rely on the old _dosmapperr() function.
Add ERROR_NO_UNICODE_TRANSLATION (1113) -> EILSEQ.

3 files changed, 138 insertions, 109 deletions

diff --git a/Misc/NEWS.d/next/Windows/2019-08-30-15-15-22.bpo-37705.2o4NWW.rst b/Misc/NEWS.d/next/Windows/2019-08-30-15-15-22.bpo-37705.2o4NWW.rst
new file mode 100644
index 0000000000..a374c3a296
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2019-08-30-15-15-22.bpo-37705.2o4NWW.rst
@@ -0,0 +1 @@
+Improve the implementation of ``winerror_to_errno()``.
diff --git a/PC/errmap.h b/PC/errmap.h
index 985f673a46..a7489ab75c 100644
--- a/PC/errmap.h
+++ b/PC/errmap.h
@@ -1,80 +1,140 @@
-/* Generated file. Do not edit. */
-int winerror_to_errno(int winerror)
+int
+winerror_to_errno(int winerror)
 {
-    switch(winerror) {
-        case 2: return 2;
-        case 3: return 2;
-        case 4: return 24;
-        case 5: return 13;
-        case 6: return 9;
-        case 7: return 12;
-        case 8: return 12;
-        case 9: return 12;
-        case 10: return 7;
-        case 11: return 8;
-        case 15: return 2;
-        case 16: return 13;
-        case 17: return 18;
-        case 18: return 2;
-        case 19: return 13;
-        case 20: return 13;
-        case 21: return 13;
-        case 22: return 13;
-        case 23: return 13;
-        case 24: return 13;
-        case 25: return 13;
-        case 26: return 13;
-        case 27: return 13;
-        case 28: return 13;
-        case 29: return 13;
-        case 30: return 13;
-        case 31: return 13;
-        case 32: return 13;
-        case 33: return 13;
-        case 34: return 13;
-        case 35: return 13;
-        case 36: return 13;
-        case 53: return 2;
-        case 65: return 13;
-        case 67: return 2;
-        case 80: return 17;
-        case 82: return 13;
-        case 83: return 13;
-        case 89: return 11;
-        case 108: return 13;
-        case 109: return 32;
-        case 112: return 28;
-        case 114: return 9;
-        case 128: return 10;
-        case 129: return 10;
-        case 130: return 9;
-        case 132: return 13;
-        case 145: return 41;
-        case 158: return 13;
-        case 161: return 2;
-        case 164: return 11;
-        case 167: return 13;
-        case 183: return 17;
-        case 188: return 8;
-        case 189: return 8;
-        case 190: return 8;
-        case 191: return 8;
-        case 192: return 8;
-        case 193: return 8;
-        case 194: return 8;
-        case 195: return 8;
-        case 196: return 8;
-        case 197: return 8;
-        case 198: return 8;
-        case 199: return 8;
-        case 200: return 8;
-        case 201: return 8;
-        case 202: return 8;
-        case 206: return 2;
-        case 215: return 11;
-        case 232: return 32;
-        case 267: return 20;
-        case 1816: return 12;
-        default: return EINVAL;
+    // Unwrap FACILITY_WIN32 HRESULT errors.
+    if ((winerror & 0xFFFF0000) == 0x80070000) {
+        winerror &= 0x0000FFFF;
+    }
+
+    // Winsock error codes (10000-11999) are errno values.
+    if (winerror >= 10000 && winerror < 12000) {
+        switch (winerror) {
+        case WSAEINTR:
+        case WSAEBADF:
+        case WSAEACCES:
+        case WSAEFAULT:
+        case WSAEINVAL:
+        case WSAEMFILE:
+            // Winsock definitions of errno values. See WinSock2.h
+            return winerror - 10000;
+        default:
+            return winerror;
+        }
+    }
+
+    switch (winerror) {
+    case ERROR_FILE_NOT_FOUND:            //    2
+    case ERROR_PATH_NOT_FOUND:            //    3
+    case ERROR_INVALID_DRIVE:             //   15
+    case ERROR_NO_MORE_FILES:             //   18
+    case ERROR_BAD_NETPATH:               //   53
+    case ERROR_BAD_NET_NAME:              //   67
+    case ERROR_BAD_PATHNAME:              //  161
+    case ERROR_FILENAME_EXCED_RANGE:      //  206
+        return ENOENT;
+
+    case ERROR_BAD_ENVIRONMENT:           //   10
+        return E2BIG;
+
+    case ERROR_BAD_FORMAT:                //   11
+    case ERROR_INVALID_STARTING_CODESEG:  //  188
+    case ERROR_INVALID_STACKSEG:          //  189
+    case ERROR_INVALID_MODULETYPE:        //  190
+    case ERROR_INVALID_EXE_SIGNATURE:     //  191
+    case ERROR_EXE_MARKED_INVALID:        //  192
+    case ERROR_BAD_EXE_FORMAT:            //  193
+    case ERROR_ITERATED_DATA_EXCEEDS_64k: //  194
+    case ERROR_INVALID_MINALLOCSIZE:      //  195
+    case ERROR_DYNLINK_FROM_INVALID_RING: //  196
+    case ERROR_IOPL_NOT_ENABLED:          //  197
+    case ERROR_INVALID_SEGDPL:            //  198
+    case ERROR_AUTODATASEG_EXCEEDS_64k:   //  199
+    case ERROR_RING2SEG_MUST_BE_MOVABLE:  //  200
+    case ERROR_RELOC_CHAIN_XEEDS_SEGLIM:  //  201
+    case ERROR_INFLOOP_IN_RELOC_CHAIN:    //  202
+        return ENOEXEC;
+
+    case ERROR_INVALID_HANDLE:            //    6
+    case ERROR_INVALID_TARGET_HANDLE:     //  114
+    case ERROR_DIRECT_ACCESS_HANDLE:      //  130
+        return EBADF;
+
+    case ERROR_WAIT_NO_CHILDREN:          //  128
+    case ERROR_CHILD_NOT_COMPLETE:        //  129
+        return ECHILD;
+
+    case ERROR_NO_PROC_SLOTS:             //   89
+    case ERROR_MAX_THRDS_REACHED:         //  164
+    case ERROR_NESTING_NOT_ALLOWED:       //  215
+        return EAGAIN;
+
+    case ERROR_ARENA_TRASHED:             //    7
+    case ERROR_NOT_ENOUGH_MEMORY:         //    8
+    case ERROR_INVALID_BLOCK:             //    9
+    case ERROR_NOT_ENOUGH_QUOTA:          // 1816
+        return ENOMEM;
+
+    case ERROR_ACCESS_DENIED:             //    5
+    case ERROR_CURRENT_DIRECTORY:         //   16
+    case ERROR_WRITE_PROTECT:             //   19
+    case ERROR_BAD_UNIT:                  //   20
+    case ERROR_NOT_READY:                 //   21
+    case ERROR_BAD_COMMAND:               //   22
+    case ERROR_CRC:                       //   23
+    case ERROR_BAD_LENGTH:                //   24
+    case ERROR_SEEK:                      //   25
+    case ERROR_NOT_DOS_DISK:              //   26
+    case ERROR_SECTOR_NOT_FOUND:          //   27
+    case ERROR_OUT_OF_PAPER:              //   28
+    case ERROR_WRITE_FAULT:               //   29
+    case ERROR_READ_FAULT:                //   30
+    case ERROR_GEN_FAILURE:               //   31
+    case ERROR_SHARING_VIOLATION:         //   32
+    case ERROR_LOCK_VIOLATION:            //   33
+    case ERROR_WRONG_DISK:                //   34
+    case ERROR_SHARING_BUFFER_EXCEEDED:   //   36
+    case ERROR_NETWORK_ACCESS_DENIED:     //   65
+    case ERROR_CANNOT_MAKE:               //   82
+    case ERROR_FAIL_I24:                  //   83
+    case ERROR_DRIVE_LOCKED:              //  108
+    case ERROR_SEEK_ON_DEVICE:            //  132
+    case ERROR_NOT_LOCKED:                //  158
+    case ERROR_LOCK_FAILED:               //  167
+    case 35:                              //   35 (undefined)
+        return EACCES;
+
+    case ERROR_FILE_EXISTS:               //   80
+    case ERROR_ALREADY_EXISTS:            //  183
+        return EEXIST;
+
+    case ERROR_NOT_SAME_DEVICE:           //   17
+        return EXDEV;
+
+    case ERROR_DIRECTORY:                 //  267 (bpo-12802)
+        return ENOTDIR;
+
+    case ERROR_TOO_MANY_OPEN_FILES:       //    4
+        return EMFILE;
+
+    case ERROR_DISK_FULL:                 //  112
+        return ENOSPC;
+
+    case ERROR_BROKEN_PIPE:               //  109
+    case ERROR_NO_DATA:                   //  232 (bpo-13063)
+        return EPIPE;
+
+    case ERROR_DIR_NOT_EMPTY:             //  145
+        return ENOTEMPTY;
+
+    case ERROR_NO_UNICODE_TRANSLATION:    // 1113
+        return EILSEQ;
+
+    case ERROR_INVALID_FUNCTION:          //    1
+    case ERROR_INVALID_ACCESS:            //   12
+    case ERROR_INVALID_DATA:              //   13
+    case ERROR_INVALID_PARAMETER:         //   87
+    case ERROR_NEGATIVE_SEEK:             //  131
+    default:
+        return EINVAL;
     }
 }
diff --git a/PC/generrmap.c b/PC/generrmap.c
deleted file mode 100644
index 953344c0d7..0000000000
--- a/PC/generrmap.c
+++ /dev/null
@@ -1,32 +0,0 @@
-#include <windows.h>
-#include <fcntl.h>
-#include <io.h>
-#include <stdio.h>
-#include <errno.h>
-
-/* Extract the mapping of Win32 error codes to errno */
-
-int main()
-{
-    int i;
-    _setmode(fileno(stdout), O_BINARY);
-    printf("/* Generated file. Do not edit. */\n");
-    printf("int winerror_to_errno(int winerror)\n");
-    printf("{\n    switch(winerror) {\n");
-    for(i=1; i < 65000; i++) {
-        _dosmaperr(i);
-        if (errno == EINVAL) {
-            /* Issue #12802 */
-            if (i == ERROR_DIRECTORY)
-                errno = ENOTDIR;
-            /* Issue #13063 */
-            else if (i == ERROR_NO_DATA)
-                errno = EPIPE;
-            else
-                continue;
-        }
-        printf("        case %d: return %d;\n", i, errno);
-    }
-    printf("        default: return EINVAL;\n");
-    printf("    }\n}\n");
-}