[Bug fortran/85192] New: Memory leak on every read() from string

[Vasilis.Vlachoudis at cern dot ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85192

            Bug ID: 85192
           Summary: Memory leak on every read() from string
           Product: gcc
           Version: 7.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: Vasilis.Vlachoudis at cern dot ch
  Target Milestone: ---

Every "READ(line,*) vars" statement from a string has a memory leak.

Example
         real*8  x, y, z, u, v, w, erg, tme, wgt
         character*250 line
         line='1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10'
         nstart = meminfo()
         do i=1,10
            read(line,*) x,y,z,u,v,w,erg,tme,wgt,ij
*            print *, x,y,z,u,v,w,erg,tme,wgt,ij
            print *,meminfo()-nstart
         enddo
         end

Compiled together with meminfo.c
#include <malloc.h>
int meminfo_()
{
        struct mallinfo mi;
        mi = mallinfo();
        return mi.uordblks;
} /* meminfo_ */

It will return a constantly increasing heap size

gcc -c meminfo.c
$ gfortran test.f meminfo.o
$ a.out
        3296
        4320
        5344
        6368
        7392
        8416
        9440
       10368
       11296
       12224