[Bug fortran/23248] New: Error using function returning array as subroutine argument

["f dot a dot akeroyd at rl dot ac dot uk" <gcc-bugzilla at gcc dot gnu dot org>]

When nesting a function that returns an array result within a call to 
a subroutine I get either segmentation or "double free" errors with gfortran. 
I am using gfortran 4.0.1 on Fedora Core 4

$ gfortran -v
Using built-in specs.
Target: i386-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --
infodir=/usr/share/info --enable-shared --enable-threads=posix --enable-
checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-
exceptions --enable-libgcj-multifile --enable-
languages=c,c++,objc,java,f95,ada --enable-java-awt=gtk --with-java-
home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --host=i386-redhat-linux Thread 
model: posix gcc version 4.0.1 20050727 (Red Hat 4.0.1-5)

$ uname -a
Linux localhost.localdomain 2.6.12-1.1398_FC4 #1 Fri Jul 15 00:52:32 EDT 2005 
i686 athlon i386 GNU/Linux

$ gfortran  -g -O0 test.f90
$ gdb a.out 
GNU gdb Red Hat Linux (6.3.0.0-1.21rh) Copyright 2004 Free Software 
Foundation, Inc. GDB is free software, covered by the GNU General Public 
License, and you are welcome to change it and/or distribute copies of it under 
certain conditions. Type "show copying" to see the conditions. There is 
absolutely no warranty for GDB.  Type "show warranty" for details. This GDB 
was configured as "i386-redhat-linux-gnu"...Using host libthread_db 
library "/lib/libthread_db.so.1".

(gdb) r
Starting program: a.out
Reading symbols from shared object read from target memory...done. Loaded 
system supplied DSO at 0xc2b000

Program received signal SIGSEGV, Segmentation fault.
0x08048644 in __testmodule__func2 (__result=@0xbff7e770, string=@0x8048888,
    flag=@0x8048890, _string=5) at test.f90:16
16                  array(i) = ichar(string(i:i))
Current language:  auto; currently fortran
(gdb)

$ cat test.f90
MODULE testmodule
   IMPLICIT NONE
   INTEGER, PARAMETER, PUBLIC :: i1 = selected_int_kind(2) 
CONTAINS
   subroutine sub1 (array3)
      INTEGER(kind=i1),intent(in) :: array3(:)
   END subroutine sub1

   FUNCTION func2 (string,flag) RESULT (array)
      CHARACTER(len=*), INTENT(in) :: string
      INTEGER(kind=i1) :: array(255)
      INTEGER :: i
      logical flag
      if (flag) then
         DO i = 1,min(len_trim(string),(size(array)-1))
            array(i) = ichar(string(i:i))
         END DO
         array(len_trim(string)+1) = 0
      endif
   END FUNCTION func2
END MODULE testmodule

program test
use testmodule
implicit none
INTEGER(kind=i1) :: array2(255)
array2 = func2('hello',.false.)   ! OK
array2 = func2('hello',.true.)    ! OK
call sub1(func2('hello',.false.)) ! "Possible double free of temporary" error  
call sub1(func2('hello',.true.))  ! casues "segmentation fault" in func2
end

-- 
           Summary: Error using function returning array as subroutine
                    argument
           Product: gcc
           Version: 4.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: f dot a dot akeroyd at rl dot ac dot uk
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: i386-redhat-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23248