Fix building of MySQL DBI extension on VS 2015+.

extensions/mysql/AMBuilder

@@ -28,9 +28,6 @@ if SM.mysql_root:
       'wsock32.lib'
     ]
 
-  if binary.compiler.vendor == 'msvc' and binary.compiler.version >= 1900:
-    binary.compiler.linkflags += ['legacy_stdio_definitions.lib', 'legacy_stdio_wide_specifiers.lib']
-
   binary.sources += [
     '../../public/smsdk_ext.cpp',
     'mysql/MyBasicResults.cpp',
@@ -40,5 +37,10 @@ if SM.mysql_root:
     'mysql/MyStatement.cpp',
     'extension.cpp'
   ]
+
+  if binary.compiler.vendor == 'msvc' and binary.compiler.version >= 1900:
+    binary.sources += [ 'msvc15hack.c' ]
+    binary.compiler.linkflags += ['legacy_stdio_definitions.lib', 'legacy_stdio_wide_specifiers.lib']
+
   SM.extensions += [builder.Add(binary)]
 

extensions/mysql/msvc15hack.c

@@ -0,0 +1,97 @@
+// Adapted from dosmap.c in Visual Studio 12.0 CRT sources.
+//
+// The _dosmaperr function is required by the MySQL lib we use,
+// but no longer exists in the VS 14.0+ crt.
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#include <stdlib.h>
+
+static struct errentry
+{
+	DWORD oscode;      // OS return value
+	int   errnocode;   // System V error code
+
+} errtable[] =
+{
+	{ ERROR_INVALID_FUNCTION,       EINVAL    },  /* 1 */
+	{ ERROR_FILE_NOT_FOUND,         ENOENT    },  /* 2 */
+	{ ERROR_PATH_NOT_FOUND,         ENOENT    },  /* 3 */
+	{ ERROR_TOO_MANY_OPEN_FILES,    EMFILE    },  /* 4 */
+	{ ERROR_ACCESS_DENIED,          EACCES    },  /* 5 */
+	{ ERROR_INVALID_HANDLE,         EBADF     },  /* 6 */
+	{ ERROR_ARENA_TRASHED,          ENOMEM    },  /* 7 */
+	{ ERROR_NOT_ENOUGH_MEMORY,      ENOMEM    },  /* 8 */
+	{ ERROR_INVALID_BLOCK,          ENOMEM    },  /* 9 */
+	{ ERROR_BAD_ENVIRONMENT,        E2BIG     },  /* 10 */
+	{ ERROR_BAD_FORMAT,             ENOEXEC   },  /* 11 */
+	{ ERROR_INVALID_ACCESS,         EINVAL    },  /* 12 */
+	{ ERROR_INVALID_DATA,           EINVAL    },  /* 13 */
+	{ ERROR_INVALID_DRIVE,          ENOENT    },  /* 15 */
+	{ ERROR_CURRENT_DIRECTORY,      EACCES    },  /* 16 */
+	{ ERROR_NOT_SAME_DEVICE,        EXDEV     },  /* 17 */
+	{ ERROR_NO_MORE_FILES,          ENOENT    },  /* 18 */
+	{ ERROR_LOCK_VIOLATION,         EACCES    },  /* 33 */
+	{ ERROR_BAD_NETPATH,            ENOENT    },  /* 53 */
+	{ ERROR_NETWORK_ACCESS_DENIED,  EACCES    },  /* 65 */
+	{ ERROR_BAD_NET_NAME,           ENOENT    },  /* 67 */
+	{ ERROR_FILE_EXISTS,            EEXIST    },  /* 80 */
+	{ ERROR_CANNOT_MAKE,            EACCES    },  /* 82 */
+	{ ERROR_FAIL_I24,               EACCES    },  /* 83 */
+	{ ERROR_INVALID_PARAMETER,      EINVAL    },  /* 87 */
+	{ ERROR_NO_PROC_SLOTS,          EAGAIN    },  /* 89 */
+	{ ERROR_DRIVE_LOCKED,           EACCES    },  /* 108 */
+	{ ERROR_BROKEN_PIPE,            EPIPE     },  /* 109 */
+	{ ERROR_DISK_FULL,              ENOSPC    },  /* 112 */
+	{ ERROR_INVALID_TARGET_HANDLE,  EBADF     },  /* 114 */
+	{ ERROR_INVALID_HANDLE,         EINVAL    },  /* 124 */
+	{ ERROR_WAIT_NO_CHILDREN,       ECHILD    },  /* 128 */
+	{ ERROR_CHILD_NOT_COMPLETE,     ECHILD    },  /* 129 */
+	{ ERROR_DIRECT_ACCESS_HANDLE,   EBADF     },  /* 130 */
+	{ ERROR_NEGATIVE_SEEK,          EINVAL    },  /* 131 */
+	{ ERROR_SEEK_ON_DEVICE,         EACCES    },  /* 132 */
+	{ ERROR_DIR_NOT_EMPTY,          ENOTEMPTY },  /* 145 */
+	{ ERROR_NOT_LOCKED,             EACCES    },  /* 158 */
+	{ ERROR_BAD_PATHNAME,           ENOENT    },  /* 161 */
+	{ ERROR_MAX_THRDS_REACHED,      EAGAIN    },  /* 164 */
+	{ ERROR_LOCK_FAILED,            EACCES    },  /* 167 */
+	{ ERROR_ALREADY_EXISTS,         EEXIST    },  /* 183 */
+	{ ERROR_FILENAME_EXCED_RANGE,   ENOENT    },  /* 206 */
+	{ ERROR_NESTING_NOT_ALLOWED,    EAGAIN    },  /* 215 */
+	{ ERROR_NOT_ENOUGH_QUOTA,       ENOMEM    }   /* 1816 */
+};
+
+// The following two constants must be the minimum and maximum
+// values in the (contiguous) range of Exec Failure errors.
+#define MIN_EXEC_ERROR ERROR_INVALID_STARTING_CODESEG
+#define MAX_EXEC_ERROR ERROR_INFLOOP_IN_RELOC_CHAIN
+
+// These are the low and high value in the range of errors that are
+// access violations
+#define MIN_EACCES_RANGE ERROR_WRITE_PROTECT
+#define MAX_EACCES_RANGE ERROR_SHARING_BUFFER_EXCEEDED
+
+void _dosmaperr(DWORD oserrno)
+{
+	_doserrno = oserrno;
+
+	// Check the table for the OS error code
+	for (size_t i = 0; i < _countof(errtable); ++i)
+	{
+		if (oserrno == errtable[i].oscode)
+		{
+			errno = errtable[i].errnocode;
+		}
+	}
+
+	// The error code wasn't in the table.  We check for a range of
+	// EACCES errors or exec failure errors (ENOEXEC).  Otherwise
+	// EINVAL is returned.
+	if (oserrno >= MIN_EACCES_RANGE && oserrno <= MAX_EACCES_RANGE)
+		errno = EACCES;
+	else if (oserrno >= MIN_EXEC_ERROR && oserrno <= MAX_EXEC_ERROR)
+		errno = ENOEXEC;
+	else
+		errno = EINVAL;
+}