Re: [Tinycc-devel] Segfault on musl with '-run'

[Arthur Williams]

On Wed, Jul 20, 2022 at 08:20:27PM +0200, grischka wrote:
> On 20.07.2022 06:03, Arthur Williams via Tinycc-devel wrote:
> > Hi,
> >
> > Was writing an application and noticed a bug. The script can be reduced
> > to the following:
> >
> > ```
> > #!/bin/tcc -run
> > #include <time.h>
> > int main() {
> >      struct timespec start, current;
> >      clock_gettime(CLOCK_MONOTONIC, &start); // Segfaults
> > }
> > ```
> >
> > When the file is executed, it crashes at the indicated line. If I
> > explicitly compile the program and run it, it behaves correctly. Also tested
> > the same script on a glibc based machine and it also didn't crash.
> >
> > Not sure exactly what's special about the call to `clock_gettime`, but
> > replacing it with something trivial or a printf avoids the crash.
>
> Maybe tcc and the system disagree about the sizeof (struct timespec) ?
>
> -- gr

When compiling via tcc with '-run' and without it, sizeof(struct timespec) is 
the
same (16).

I did attempt to generate a backtrace to debug. However, I got the
following errors
```
tcc: error: undefined symbol 'strchr'
tcc: error: undefined symbol 'stderr'
tcc: error: undefined symbol 'fprintf'
tcc: error: undefined symbol 'fflush'
```
when I changed the shebang to '#!/bin/tcc -run -g -bt4'.

Probably should have first stated that I was using 1.2.2. Upgrading to
1.2.3 didn't change the behavior though.

Arthur