[newlib-cygwin] Cygwin: Treat PROCESSOR_ARCHITECTURE_INTEL as running under WOW64 on ARM64

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=5ed8f2354fd6476deb68845174f53fa8f13b42b7

commit 5ed8f2354fd6476deb68845174f53fa8f13b42b7
Author: Corinna Vinschen <***@vinschen.de>
Date: Thu Jul 12 15:28:13 2018 +0200

Cygwin: Treat PROCESSOR_ARCHITECTURE_INTEL as running under WOW64 on ARM64

Bug in current ARM64 WOW64: GetNativeSystemInfo returns
PROCESSOR_ARCHITECTURE_INTEL rather than PROCESSOR_ARCHITECTURE_ARM64.
Provide for this.

Make code better readable.

Signed-off-by: Corinna Vinschen <***@vinschen.de>

Diff:
---
winsup/cygwin/path.cc | 33 ++++++++++++++++++++++++---------
1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 3936b10..6d8f76d 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -4306,19 +4306,34 @@ find_fast_cwd ()
fcwd_access_t **f_cwd_ptr = find_fast_cwd_pointer ();
if (!f_cwd_ptr)
{
+ bool warn = 1;
+
#ifndef __x86_64__
-#ifndef PROCESSOR_ARCHITECTURE_ARM64
-#define PROCESSOR_ARCHITECTURE_ARM64 12
-#endif
+ #ifndef PROCESSOR_ARCHITECTURE_ARM64
+ #define PROCESSOR_ARCHITECTURE_ARM64 12
+ #endif
+
SYSTEM_INFO si;

/* Check if we're running in WOW64 on ARM64. Skip the warning as long as
- there's no solution for finding the FAST_CWD pointer on that system. */
- if (wincap.is_wow64 ()
- && (GetNativeSystemInfo (&si),
- si.wProcessorArchitecture != PROCESSOR_ARCHITECTURE_ARM64))
-#endif
- small_printf ("Cygwin WARNING:\n"
+ there's no solution for finding the FAST_CWD pointer on that system.
+
+ 2018-07-12: Apparently current ARM64 WOW64 has a bug:
+ It's GetNativeSystemInfo returns PROCESSOR_ARCHITECTURE_INTEL in
+ wProcessorArchitecture. Since that's an invalid value (a 32 bit
+ host system hosting a 32 bit emulator for itself?) we can use this
+ value as an indicator to skip the message as well. */
+ if (wincap.is_wow64 ())
+ {
+ GetNativeSystemInfo (&si);
+ if (si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_ARM64
+ || si.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_INTEL)
+ warn = 0;
+ }
+#endif /* !__x86_64__ */
+
+ if (warn)
+ small_printf ("Cygwin WARNING:\n"
" Couldn't compute FAST_CWD pointer. This typically occurs if you're using\n"
" an older Cygwin version on a newer Windows. Please update to the latest\n"
" available Cygwin version from https://cygwin.com/. If the problem persists,\n"