[newlib-cygwin] Cygwin: 32 bit: remove old code to 16 bit align stack

[newlib-cygwin] Cygwin: 32 bit: remove old code to 16 bit align stack

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=a834dc1ba923d33a87f0dc3be0e23a9aa81603b8

commit a834dc1ba923d33a87f0dc3be0e23a9aa81603b8
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Fri Feb 28 14:31:56 2020 +0100

    Cygwin: 32 bit: remove old code to 16 bit align stack
    
    Aligning the stack pointer using an asm statement isn't any longer
    supported.  gcc-9.2.0 generates the following warning:
    
      init.cc:33:46: error: listing the stack pointer register '%esp'
      in a clobber list is deprecated [-Werror=deprecated]
      [...]
      init.cc:33:46: note: the value of the stack pointer after an
      'asm' statement must be the same as it was before the statement
    
    Replace the asm expression with the gcc function attribute
    `force_align_arg_pointer'.  This aligns the stack exactly as
    required.
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/crt0.c  | 14 +++-----------
 winsup/cygwin/init.cc | 13 +++----------
 2 files changed, 6 insertions(+), 21 deletions(-)

diff --git a/winsup/cygwin/crt0.c b/winsup/cygwin/crt0.c
index fee4b2e..ec7959a 100644
--- a/winsup/cygwin/crt0.c
+++ b/winsup/cygwin/crt0.c
@@ -16,20 +16,12 @@ extern int main (int argc, char **argv);
 
 void cygwin_crt0 (int (*main) (int, char **));
 
+#ifdef __i386__
+__attribute__ ((force_align_arg_pointer))
+#endif
 void
 mainCRTStartup ()
 {
-#ifdef __i386__
-#if __GNUC_PREREQ(6,0)
-#pragma GCC diagnostic ignored "-Wframe-address"
-#endif
-  (void)__builtin_return_address(1);
-#if __GNUC_PREREQ(6,0)
-#pragma GCC diagnostic pop
-#endif
-  asm volatile ("andl $-16,%%esp" ::: "%esp");
-#endif
-
   cygwin_crt0 (main);
 
   /* These are never actually called.  They are just here to force the inclusion
diff --git a/winsup/cygwin/init.cc b/winsup/cygwin/init.cc
index 851a7ff..7787b16 100644
--- a/winsup/cygwin/init.cc
+++ b/winsup/cygwin/init.cc
@@ -19,19 +19,12 @@ unsigned threadfunc_ix[8];
 static bool dll_finished_loading;
 #define OLDFUNC_OFFSET -1
 
+#ifdef __i386__
+__attribute__ ((force_align_arg_pointer))
+#endif
 static void WINAPI
 threadfunc_fe (VOID *arg)
 {
-#ifdef __i386__
-#if __GNUC_PREREQ(6,0)
-#pragma GCC diagnostic ignored "-Wframe-address"
-#endif
-  (void)__builtin_return_address(1);
-#if __GNUC_PREREQ(6,0)
-#pragma GCC diagnostic pop
-#endif
-  asm volatile ("andl $-16,%%esp" ::: "%esp");
-#endif
   _cygtls::call ((DWORD (*)  (void *, void *)) TlsGetValue (_my_oldfunc), arg);
 }