ABI-Testsuite/test/misc/sg_2.xpp

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// RUN: cxx_compiler -c %s cxx_rtti -o %t1.o
// RUN: linker -o %t%exeext %t1.o
// RUN: runtool %t%exeext | grep "PASSED"




// check that __cxa_guard_acuire, __cxa_gaurd_release and __cxa_guard_abort are doing 
// their jobs
//
//

extern "C" {
  int printf(const char *, ...);
  int __cxa_guard_acquire(long long *);
  void __cxa_guard_release(long long *);
  void __cxa_guard_abort(long long *);
}

#if 0

extern "C" int __cxa_guard_acquire ( __int64_t *guard_object );

    Returns 1 if the initialization is not yet complete; 0 otherwise. This function is called before initialization takes place. If this function returns 1, either __cxa_guard_release or __cxa_guard_abort must be called with the same argument. The first byte of the guard_object is not modified by this function.

    A thread-safe implementation will probably guard access to the first byte of the guard_object with a mutex. If this function returns 1, the mutex will have been acquired by the calling thread.

extern "C" void __cxa_guard_release ( __int64_t *guard_object );

    Sets the first byte of the guard object to a non-zero value. This function is called after initialization is complete.

    A thread-safe implementation will release the mutex acquired by __cxa_guard_acquire after setting the first byte of the guard object.

extern "C" void __cxa_guard_abort ( __int64_t *guard_object );

    This function is called if the initialization terminates by throwing an exception.

    A thread-safe implementation will release the mutex acquired by __cxa_guard_acquire.

<b>NOTE</b>:

#endif

static int nerr;
#define ERR(a) {printf("@%d %s\n", __LINE__, a); nerr++;}

int main()
{
   long long gv = 0, gv2 = 0;
   unsigned char *gp = (unsigned char *) &gv;
   // simple case aquire should succeed and return 1. 

   if (!__cxa_guard_acquire(&gv)) ERR("FAILED TO ACQUIRE");

   if (gp[0]) ERR("Lowest byte of the Guard var set prematurely");
   // other buytes could be set at this point

   // now release
   __cxa_guard_release(&gv);
   if (!gv) ERR("Guard var not set"); 
   if (!gp[0]) ERR("first byte 0");
   if (gp[1]||gp[2]||gp[3]||gp[4]||gp[5]||gp[6]||gp[7]) ERR("Other bytes set");

   long long gs = gv;

   // A second call should fail
   if (__cxa_guard_acquire(&gv)) ERR("Acquired again")
   
   // should not change gv
   if (gs != gv) ERR("gv changed by a failing call");

   // now test abort
   gp = (unsigned char *)&gv2;
   if (!__cxa_guard_acquire(&gv2)) ERR("FAILED TO ACQUIRE gv2");
   if (gp[0]) ERR("Lowest byte of the Guard var set prematurely");

   __cxa_guard_abort(&gv2);
   if (gv2) ERR("Guard var set by abort ");
   if (!__cxa_guard_acquire(&gv2)) ERR("FAILED TO ACQUIRE gv2");
   if (gp[0]) ERR("Lowest byte of the Guard var set prematurely");

   // now release
   __cxa_guard_release(&gv2);
   if (!gv2) ERR("Guard var not set"); 
   if (!gp[0]) ERR("first byte 0");
   if (gp[1]||gp[2]||gp[3]||gp[4]||gp[5]||gp[6]||gp[7]) ERR("Other bytes set");
   printf("%s\n", nerr ? "FAILED" : "PASSED");
   return nerr;
}