crt: Redirect access() to __mingw_access() on UCRT

__mingw_access() was introduced as the msvcrt.dll access() function
reportedly returned errors when passed the X_OK constant on
Vista.

Users who expect to be calling access() with the X_OK constant could
set the __USE_MINGW_ACCESS define to get a mingw specific reimplementation
of the function. GCC has been setting this define to work around this
issue (but there have been cases where the define hasn't applied on all
the source where it's needed).

Current versions of msvcrt.dll no longer seem to have this issue
with X_OK, so the issue has somewhat been forgotten since. But UCRT's
access() function shows the same behaviour of returning errors when
given that constant.

Always defining __USE_MINGW_ACCESS when building targeting UCRT
doesn't work, as the define of access() breaks other valid cases
(e.g. calls to methods named access() in C++ classes).

Instead remove the access() symbol from the import libraries, and
expose an UCRT specific access() that just redirects to __mingw_access().

Signed-off-by: Martin Storsjö <martin@martin.st>

mingw-w64-crt/Makefile.am

@@ -240,6 +240,7 @@ src_ucrtbase=\
   crt/ucrtbase_compat.c \
   math/_huge.c \
   misc/__initenv.c \
+  misc/ucrt-access.c \
   stdio/ucrt_fprintf.c \
   stdio/ucrt_fscanf.c \
   stdio/ucrt_fwprintf.c \

mingw-w64-crt/def-include/msvcrt-common.def.in

@@ -12,7 +12,11 @@ wcscmpi == _wcsicmp
 strcasecmp == _stricmp
 strncasecmp == _strnicmp
 
+#ifdef UCRTBASE
+; access is provided as an alias for __mingw_access
+#else
 ADD_UNDERSCORE(access)
+#endif
 ADD_UNDERSCORE(chdir)
 ADD_UNDERSCORE(chmod)
 ADD_UNDERSCORE(chsize)

mingw-w64-crt/lib-common/api-ms-win-crt-filesystem-l1-1-0.def

@@ -3,7 +3,8 @@ LIBRARY api-ms-win-crt-filesystem-l1-1-0
 EXPORTS
 
 _access
-access == _access
+; access is provided as an alias for __mingw_access
+; access == _access
 _access_s
 _chdir
 chdir == _chdir

mingw-w64-crt/misc/ucrt-access.c

@@ -0,0 +1,19 @@
+/**
+ * This file has no copyright assigned and is placed in the Public Domain.
+ * This file is part of the mingw-w64 runtime package.
+ * No warranty is given; refer to the file DISCLAIMER.PD within this package.
+ */
+
+#include <io.h>
+
+int __cdecl __mingw_access(const char *fname, int mode);
+
+int __cdecl access(const char *fname, int mode)
+{
+  /* On UCRT, unconditionally forward access to __mingw_access. UCRT's
+   * access() function return an error if passed the X_OK constant,
+   * while msvcrt.dll's access() doesn't. (It's reported that msvcrt.dll's
+   * access() also returned errors on X_OK in the version shipped in Vista,
+   * but in recent tests it's no longer the case.) */
+  return __mingw_access(fname, mode);
+}