[Bug fortran/52418] New: (unnecessary) automatic reallocation of lhs causes segfault

[therobbot at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52418

             Bug #: 52418
           Summary: (unnecessary) automatic reallocation of lhs causes
                    segfault
    Classification: Unclassified
           Product: gcc
           Version: 4.6.2
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: therobbot@gmail.com


Created attachment 26771
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26771
program to reproduce bug

The following program causes a segfault:

PROGRAM reshape_test
  IMPLICIT NONE
  REAL, DIMENSION(:,:), ALLOCATABLE :: m2
  REAL, DIMENSION(:,:,:), ALLOCATABLE :: m3
  ALLOCATE( m2( 6, 1 ), m3( 2, 3, 1 ) )
  m2 = -1
  m3 = RESHAPE( m2, SHAPE(m3) )
  m3 = 2
  WRITE(*,*) 'm3(1,1,1) = ', m3(1,1,1)
END PROGRAM reshape_test

If compiled with -fno-realloc-lhs, the code runs as expected. There really
shouldn't be any reallocation here, so this shouldn't make a difference. Either
way it should not cause a segfault.

Side note: I love all of the work on f2003/2008! The OO features make fortran
fun again. Thanks!