PR fortran/86045 -- test for P=0 in mod(, 0)

Message ID 20180605010109.GA14193@troutmask.apl.washington.edu
State New
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  • PR fortran/86045 -- test for P=0 in mod(, 0)
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Commit Message

Steve Kargl June 5, 2018, 1:01 a.m.
The attached patch re-arranges the code in gfc_simply_mod().
This allows gfortran to test if the 2nd argument is zero.
Tested on i586-*-freebsd and x86_64-*-freebsd.  OK to commit?

2018-06-04  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/86045
	* simplify.c (gfc_simplify_mod): Re-arrange code to test whether
	'P' is zero and issue an error if it is.

2018-06-04  Steven G. Kargl  <kargl@gcc.gnu.org>

	PR fortran/86045
	* gfortran.dg/pr86045.f90: New test.

-- 
Steve

Comments

Thomas Koenig June 6, 2018, 7:32 p.m. | #1
Hi Steve,

> The attached patch re-arranges the code in gfc_simply_mod().

> This allows gfortran to test if the 2nd argument is zero.

> Tested on i586-*-freebsd and x86_64-*-freebsd.  OK to commit?


OK.

Thanks for the patch!

Regards

	Thomas

Patch

Index: gcc/fortran/simplify.c
===================================================================
--- gcc/fortran/simplify.c	(revision 261171)
+++ gcc/fortran/simplify.c	(working copy)
@@ -5473,41 +5473,46 @@  gfc_simplify_mod (gfc_expr *a, gfc_expr *p)
   gfc_expr *result;
   int kind;
 
-  if (a->expr_type != EXPR_CONSTANT || p->expr_type != EXPR_CONSTANT)
+  /* First check p.  */
+  if (p->expr_type != EXPR_CONSTANT)
     return NULL;
 
-  kind = a->ts.kind > p->ts.kind ? a->ts.kind : p->ts.kind;
-  result = gfc_get_constant_expr (a->ts.type, kind, &a->where);
-
-  switch (a->ts.type)
+  /* p shall not be 0.  */
+  switch (p->ts.type)
     {
       case BT_INTEGER:
 	if (mpz_cmp_ui (p->value.integer, 0) == 0)
 	  {
-	    /* Result is processor-dependent.  */
-	    gfc_error ("Second argument MOD at %L is zero", &a->where);
-	    gfc_free_expr (result);
+	    gfc_error ("Argument %qs of MOD at %L shall not be zero",
+			"P", &p->where);
 	    return &gfc_bad_expr;
 	  }
-	mpz_tdiv_r (result->value.integer, a->value.integer, p->value.integer);
 	break;
-
       case BT_REAL:
 	if (mpfr_cmp_ui (p->value.real, 0) == 0)
 	  {
-	    /* Result is processor-dependent.  */
-	    gfc_error ("Second argument of MOD at %L is zero", &p->where);
-	    gfc_free_expr (result);
+	    gfc_error ("Argument %qs of MOD at %L shall not be zero",
+			"P", &p->where);
 	    return &gfc_bad_expr;
 	  }
-
-	gfc_set_model_kind (kind);
-	mpfr_fmod (result->value.real, a->value.real, p->value.real,
-		   GFC_RND_MODE);
 	break;
-
       default:
 	gfc_internal_error ("gfc_simplify_mod(): Bad arguments");
+    }
+
+  if (a->expr_type != EXPR_CONSTANT)
+    return NULL;
+
+  kind = a->ts.kind > p->ts.kind ? a->ts.kind : p->ts.kind;
+  result = gfc_get_constant_expr (a->ts.type, kind, &a->where);
+
+  if (a->ts.type == BT_INTEGER)
+    mpz_tdiv_r (result->value.integer, a->value.integer, p->value.integer);
+  else
+    {
+      gfc_set_model_kind (kind);
+      mpfr_fmod (result->value.real, a->value.real, p->value.real,
+		 GFC_RND_MODE);
     }
 
   return range_check (result, "MOD");
Index: gcc/testsuite/gfortran.dg/pr86045.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr86045.f90	(nonexistent)
+++ gcc/testsuite/gfortran.dg/pr86045.f90	(working copy)
@@ -0,0 +1,7 @@ 
+! { dg-do compile }
+program p
+   logical :: a(2) = (mod([2,3],0) == 0)     ! { dg-error "shall not be zero" }
+   integer :: b = count(mod([2,3],0) == 0)   ! { dg-error "shall not be zero" }
+   integer :: c = all(mod([2,3],0) == 0)     ! { dg-error "shall not be zero" }
+   integer :: d = any(mod([2,3],0) == 0)     ! { dg-error "shall not be zero" }
+end