bug#5847: [Hubert Gosselmeyer] Re: bug#5847: ETAGS: Segmentation fault, because of incorrect scope presumption

[Alex <agrambot@gmail.com>]

[-- Attachment #0: Type: message/rfc822, Size: 927761 bytes --]

[-- Attachment #1.1.1: Type: text/plain, Size: 1043 bytes --]

Hi Alex,

I rechecked the issue with my new hardware (got a new laptop meanwhile).
The issue does not occur for the files attached on the bug report anymore.

As I suspect that it has something to do with large memory allocation, I
produced some larger files
with an python script. I tested it on my machine still with etags (GNU
Emacs 23.1) and gave the files
to a collegue, who tested it with etags (GNU Emacs 24.3). On both etags
crashed for test_seg.c.






On Sun, Aug 14, 2016 at 11:38 PM, Alex <agrambot@gmail.com> wrote:

> Hubert Gosselmeyer <gosselmeyer@googlemail.com> writes:
>
> > Hi,
> >
> > the GNU Emacs TAGS tool 'etags' seems to have problems if source code is
> not
> > probably indented and new scopes are created within procedures. I found
> this
> > out by using etags on generated code where a lot of structures where
> created
> > on the heap, initialized and assigned to an array of pointers.
>
> Hi, do you still encounter this issue? I tried to reproduce with Emacs
> 24.5 but both files did not segfault for me.
>

[-- Attachment #1.1.2: Type: text/html, Size: 1562 bytes --]

[-- Attachment #1.2: test_noseg.c.gz --]
[-- Type: application/x-gzip, Size: 369681 bytes --]

[-- Attachment #1.3: test_seg.c.gz --]
[-- Type: application/x-gzip, Size: 311652 bytes --]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1.4: segf.py --]
[-- Type: text/x-python; name=segf.py, Size: 699 bytes --]

from subprocess import call

with open('test_seg.c', 'w') as f:
    f.write("""
struct test {
  long i;
};

struct test* testArr[32000];

long i;

int main(){

  i = 0;
)
""")    
    for i in range(1, 900000):
        f.write("""
{
  struct test *t = malloc(sizeof(struct test));
  i++;
  t->i = i;

  testArr[i] = t;
  free(t);
}
""")
    f.write("}")




with open('test_noseg.c', 'w') as f:
    f.write("""
struct test {
  long i;
};

struct test* testArr[32000];

long i;

int main(){

  i = 0;
)
""")    
    for i in range(1, 900000):
        f.write("""
  {
    struct test *t = malloc(sizeof(struct test));
    i++;
    t->i = i;

    testArr[i] = t;
    free(t);
  }
""")
    f.write("}")