[Patch, fortran] PR29758 - Runtime segfault in RESHAPE with insufficient elements in SOURCE

[Paul Thomas]

Ping!

I would not do this so soon, were I not on my travels again on Sunday.  
If it goes to trunk this weekend, it can be committed to 4.2/4.1 the 
following weekend.

Cheers

Paul
> :ADDPATCH fortran:
>
> This patch checks to see if there are enough elements in reshape's 
> source to match shape, when shape is a constant array and source has a 
> constant shape.  It is a self explanatory bit of hacking in check.c.  
> The testcase checks two obvious errors and checks that a correct one 
> goes through.
>
> Regtested Suse10.1/amd64.
>
> OK for trunk, 4.2 and 4.1?
>
> Paul
>
> 2006-11-08  Paul Thomas <pault@gcc.gnu.org>
>
>    PR fortran/29758
>    * check.c (gfc_check_reshape): Check that there are enough
>    elements in the source array as to be able to fill an array
>    defined by shape, when pad is absent.
>
> 2006-11-08  Paul Thomas  <pault@gcc.gnu.org>
>
>    PR fortran/29758
>    * gfortran.dg/reshape_source_size_1.f90: New test.
>
>
> ------------------------------------------------------------------------
>
> Index: gcc/fortran/check.c
> ===================================================================
> *** gcc/fortran/check.c	(revision 118597)
> --- gcc/fortran/check.c	(working copy)
> *************** gfc_check_reshape (gfc_expr * source, gf
> *** 2110,2115 ****
> --- 2110,2116 ----
>   		   gfc_expr * pad, gfc_expr * order)
>   {
>     mpz_t size;
> +   mpz_t nelems;
>     int m;
>   
>     if (array_check (source, 0) == FAILURE)
> *************** gfc_check_reshape (gfc_expr * source, gf
> *** 2149,2154 ****
> --- 2150,2187 ----
>     if (order != NULL && array_check (order, 3) == FAILURE)
>       return FAILURE;
>   
> +   if (pad == NULL
> + 	&& shape->expr_type == EXPR_ARRAY
> + 	&& gfc_is_constant_expr (shape)
> + 	&& !(source->expr_type == EXPR_VARIABLE
> + 	       && source->symtree->n.sym->as
> + 	       && source->symtree->n.sym->as->type == AS_ASSUMED_SIZE))
> +     {
> +       /* Check the match in size between source and destination.  */
> +       if (gfc_array_size (source, &nelems) == SUCCESS)
> + 	{
> + 	  gfc_constructor *c;
> + 	  bool test;
> + 
> + 	  c = shape->value.constructor;
> + 	  mpz_init_set_ui (size, 1);
> + 	  for (; c; c = c->next)
> + 	    mpz_mul (size, size, c->expr->value.integer);
> + 
> + 	  test = mpz_cmp (nelems, size) < 0 && mpz_cmp_ui (size, 0) > 0;
> + 	  mpz_clear (nelems);
> + 	  mpz_clear (size);
> + 
> + 	  if (test)
> + 	    {
> + 	      gfc_error ("Without padding, there are not enough elements in the "
> + 			 "intrinsic RESHAPE source at %L to match the shape",
> + 			 &source->where);
> + 	      return FAILURE;
> + 	    }
> + 	}
> +     }
> + 
>     return SUCCESS;
>   }
>   
> Index: gcc/testsuite/gfortran.dg/reshape_source_size_1.f90
> ===================================================================
> *** gcc/testsuite/gfortran.dg/reshape_source_size_1.f90	(revision 0)
> --- gcc/testsuite/gfortran.dg/reshape_source_size_1.f90	(revision 0)
> ***************
> *** 0 ****
> --- 1,11 ----
> + ! { dg-do compile }
> + ! Tests patch for PR29758, which arose from PR29431.  There was no check that there
> + ! were enough elements in the source to match the shape.
> + !
> + ! Contributed by Paul Thomas  <pault@gcc.gnu.org>
> + !
> +    real :: a(2,2), b = 1.0, c(3), d(4)
> +    a = reshape ([b], [2,2]) ! { dg-error "not enough elements" }
> +    a = reshape (c, [2,2])   ! { dg-error "not enough elements" }
> +    a = reshape (d, [2,2])
> + end
>