[PATCH] PR fortran/68053 -- Reduce initialization expression to constant value

[PATCH] PR fortran/68053 -- Reduce initialization expression to constant value

[Steve Kargl]

The attached patch has been built and regression tested
on i386-*-freebsd and x86_64-*-freebsd.  If an array
index in an initialization expression is an array element
from an array named constant, the array index needs to be
reduced.  This patch causes the reduction to occur.
OK to commit?

2015-11-08  Steven g. Kargl  <kargl@gcc.gnu.org>

	PR fortran/68053
	* decl.c (add_init_expr_to_sym):  Try to reduce initialization expression
	before testing for a constant value.

2015-11-08  Steven g. Kargl  <kargl@gcc.gnu.org>

	PR fortran/68053
	* gfortran.dg/pr68053.f90: New test.
-- 
Steve

Re: [PATCH] PR fortran/68053 -- Reduce initialization expression to constant value

[Steve Kargl]

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On Sun, Nov 08, 2015 at 02:35:58PM -0800, Steve Kargl wrote:
> The attached patch has been built and regression tested
> on i386-*-freebsd and x86_64-*-freebsd.  If an array
> index in an initialization expression is an array element
> from an array named constant, the array index needs to be
> reduced.  This patch causes the reduction to occur.
> OK to commit?
> 
> 2015-11-08  Steven g. Kargl  <kargl@gcc.gnu.org>
> 
> 	PR fortran/68053
> 	* decl.c (add_init_expr_to_sym):  Try to reduce initialization expression
> 	before testing for a constant value.
> 
> 2015-11-08  Steven g. Kargl  <kargl@gcc.gnu.org>
> 
> 	PR fortran/68053
> 	* gfortran.dg/pr68053.f90: New test.

Now with the patch attached!

-- 
Steve

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Index: gcc/fortran/decl.c
===================================================================
--- gcc/fortran/decl.c	(revision 229970)
+++ gcc/fortran/decl.c	(working copy)
@@ -1529,26 +1529,34 @@ add_init_expr_to_sym (const char *name, 
 	  for (dim = 0; dim < sym->as->rank; ++dim)
 	    {
 	      int k;
-	      gfc_expr* lower;
-	      gfc_expr* e;
+	      gfc_expr *e, *lower;
 
 	      lower = sym->as->lower[dim];
-	      if (lower->expr_type != EXPR_CONSTANT)
+
+	      /* If the lower bound is an array element from another 
+		 parameterized array, then it is marked with EXPR_VARIABLE and
+		 is an initialization expression.  Try to reduce it.  */
+	      if (lower->expr_type == EXPR_VARIABLE)
+		gfc_reduce_init_expr (lower);
+
+	      if (lower->expr_type == EXPR_CONSTANT)
+		{
+		  /* All dimensions must be without upper bound.  */
+		  gcc_assert (!sym->as->upper[dim]);
+
+		  k = lower->ts.kind;
+		  e = gfc_get_constant_expr (BT_INTEGER, k, &sym->declared_at);
+		  mpz_add (e->value.integer, lower->value.integer,
+			   init->shape[dim]);
+		  mpz_sub_ui (e->value.integer, e->value.integer, 1);
+		  sym->as->upper[dim] = e;
+		}
+	      else
 		{
 		  gfc_error ("Non-constant lower bound in implied-shape"
 			     " declaration at %L", &lower->where);
 		  return false;
 		}
-
-	      /* All dimensions must be without upper bound.  */
-	      gcc_assert (!sym->as->upper[dim]);
-
-	      k = lower->ts.kind;
-	      e = gfc_get_constant_expr (BT_INTEGER, k, &sym->declared_at);
-	      mpz_add (e->value.integer,
-		       lower->value.integer, init->shape[dim]);
-	      mpz_sub_ui (e->value.integer, e->value.integer, 1);
-	      sym->as->upper[dim] = e;
 	    }
 
 	  sym->as->type = AS_EXPLICIT;
Index: gcc/testsuite/gfortran.dg/pr68053.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr68053.f90	(revision 0)
+++ gcc/testsuite/gfortran.dg/pr68053.f90	(working copy)
@@ -0,0 +1,10 @@
+! { dg-do run }
+! PR fortran/68053
+! Original code contributed by Gerhard Steinmetz
+! <gerhard dot steinmetx dot fortran at t-online dot de>
+program p
+   integer, parameter :: n(3) = [1,2,3]
+   integer, parameter :: x(1) = 7
+   integer, parameter :: z(n(2):*) = x
+   if (lbound(z,1) /= 2) call abort
+end

Re: [PATCH] PR fortran/68053 -- Reduce initialization expression to constant value

[Paul Richard Thomas]

Dear Steve,

Thanks for beavering away on these front-end issues.

OK for trunk

Paul

On 8 November 2015 at 23:37, Steve Kargl
<sgk@troutmask.apl.washington.edu> wrote:
> On Sun, Nov 08, 2015 at 02:35:58PM -0800, Steve Kargl wrote:
>> The attached patch has been built and regression tested
>> on i386-*-freebsd and x86_64-*-freebsd.  If an array
>> index in an initialization expression is an array element
>> from an array named constant, the array index needs to be
>> reduced.  This patch causes the reduction to occur.
>> OK to commit?
>>
>> 2015-11-08  Steven g. Kargl  <kargl@gcc.gnu.org>
>>
>>       PR fortran/68053
>>       * decl.c (add_init_expr_to_sym):  Try to reduce initialization expression
>>       before testing for a constant value.
>>
>> 2015-11-08  Steven g. Kargl  <kargl@gcc.gnu.org>
>>
>>       PR fortran/68053
>>       * gfortran.dg/pr68053.f90: New test.
>
> Now with the patch attached!
>
> --
> Steve



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