[PATCH] eh_personality.cc: unwinding on ARM

[Peter Waechtler]

On 19.03.2012 17:38, Daniel Jacobowitz wrote:
> On Mon, Mar 19, 2012 at 12:12 PM, Andrew Stubbs<ams@codesourcery.com>  wrote:
>> On 16/03/12 13:29, EXTERNAL Waechtler Peter (Fa. TCP, CM-AI/PJ-CF31) wrote:
>>> The CodeSourcery toolchain contains a "fix" like the following,
>>> please consider for adding it.
>>
>> Here's the full original patch with ChangeLog.
>>
>> I don't know why Dan never submitted this one. Perhaps it's not suitable for
>> upstream or not considered the correct fix?
> I think it was just a pain to write a test for.
>

Here's another version using siglongjmp to avoid VERIFY in signal handler:
Can someone (maybe you) put that at the appropriate place?
Please don't let the integration being a pain as well

         Peter

seehttp://gcc.gnu.org/ml/gcc-patches/2012-03/msg01161.html


/*
         author: Peter Waechtler (pwaechtler at mac.com)
         Copyright FSF or whatever is needed

         A simple test case to verify if backtrace(3) goes into
         a loop while unwinding on ARM with cxx_personality routine.
*/
#include<unistd.h>
#include<stdlib.h>
#include<string.h>
#include<signal.h>
#include<execinfo.h>
#include<setjmp.h>

#include<iostream>
#include<vector>
using namespace std;

//#include "testsuite.h"

#define WE_PASSED 42
#define WE_FAILED 0xff

sigjmp_buf env;

static void abort_handler(int n_signal, siginfo_t *siginfo, void *ptr)
{
         void *address[20];
         int depth;

         depth = backtrace(address, sizeof(address)/sizeof(void*));

         backtrace_symbols_fd(address, depth, 0);
         /* this is a dumb check, better look for main */
         if (depth == sizeof(address)/sizeof(void*))
                 siglongjmp(env, WE_FAILED);
         else
                 siglongjmp(env, WE_PASSED);
}

static int tst_eh01(void)
{
         int rc = 0;

         std::vector<int>   v(10);
         rc = v.at(42);

         return rc;
}

int main(int argc, char *argv[])
{
         int c = 1;
         struct sigaction sa;

         memset(&sa, 0 , sizeof(sa));
         sa.sa_sigaction = abort_handler;
         sa.sa_flags = SA_SIGINFO;

         sigaction(SIGABRT,&sa, NULL);

         switch (sigsetjmp(env, 1)) {
                 case 0: /* the context was set */
                         c = tst_eh01();
                         break;
                 case WE_PASSED:
                         // VERIFY( true );
                         cerr<<  "PASSED"<<  endl;
                         break;
                 default:
                         // VERIFY( false );
                         cerr<<  "FAILED"<<  endl;
                         break;
         }

         return c;
}