[PATCH] fortran/37930 -- Fix clever user trick

[PATCH] fortran/37930 -- Fix clever user trick

[Steve Kargl]

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This patch fixes the conversion of an NaN or Inf value to
an integer by disallowing such a questionable action.


2008-10-27  Steven G. Kargl  <kargls@comcast.net>

	PR fortran/37930
	* gfortran.dg/int_conv_2.f90:  New test.

2008-10-27  Steven G. Kargl  <kargls@comcast.net>

	PR fortran/37930
	* fortran/arith.c (gfc_mpfr_to_mpz):  Test for NaN and Inf values.
	(gfc_real2int): Error on conversion of NaN or Inf.
	(gfc_complex2int): Ditto.
	* fortran/arith.h: Update mpfr_to_mpz prototype.
	* fortran/simplify.c (gfc_simplify_ceiling, gfc_simplify_floor,
	gfc_simplify_ifix, gfc_simplify_idint, simplify_nint): Update function
	calls to include locus

-- 
steve

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Index: gcc/testsuite/gfortran.dg/int_conv_2.f90
===================================================================
--- gcc/testsuite/gfortran.dg/int_conv_2.f90	(revision 0)
+++ gcc/testsuite/gfortran.dg/int_conv_2.f90	(revision 0)
@@ -0,0 +1,7 @@
+! { dg-do compile }
+! PR fortran/37930
+program test
+  implicit none
+  integer i
+  i = transfer(-1,1.0) ! { dg-error "exceptional value" }
+end program test
Index: gcc/fortran/arith.c
===================================================================
--- gcc/fortran/arith.c	(revision 141346)
+++ gcc/fortran/arith.c	(working copy)
@@ -35,10 +35,16 @@ along with GCC; see the file COPYING3.  
    It's easily implemented with a few calls though.  */
 
 void
-gfc_mpfr_to_mpz (mpz_t z, mpfr_t x)
+gfc_mpfr_to_mpz (mpz_t z, mpfr_t x, locus *where)
 {
   mp_exp_t e;
 
+  if (mpfr_inf_p (x) || mpfr_nan_p (x))
+	{
+      gfc_error ("Conversion of exceptional value at %L", where);
+      return;
+    }
+
   e = mpfr_get_z_exp (z, x);
   /* MPFR 2.0.1 (included with GMP 4.1) has a bug whereby mpfr_get_z_exp
      may set the sign of z incorrectly.  Work around that here.  */
@@ -2177,7 +2183,7 @@ gfc_real2int (gfc_expr *src, int kind)
 
   result = gfc_constant_result (BT_INTEGER, kind, &src->where);
 
-  gfc_mpfr_to_mpz (result->value.integer, src->value.real);
+  gfc_mpfr_to_mpz (result->value.integer, src->value.real, &src->where);
 
   if ((rc = gfc_check_integer_range (result->value.integer, kind)) != ARITH_OK)
     {
@@ -2263,7 +2269,7 @@ gfc_complex2int (gfc_expr *src, int kind
 
   result = gfc_constant_result (BT_INTEGER, kind, &src->where);
 
-  gfc_mpfr_to_mpz (result->value.integer, src->value.complex.r);
+  gfc_mpfr_to_mpz (result->value.integer, src->value.complex.r, &src->where);
 
   if ((rc = gfc_check_integer_range (result->value.integer, kind)) != ARITH_OK)
     {
Index: gcc/fortran/arith.h
===================================================================
--- gcc/fortran/arith.h	(revision 141346)
+++ gcc/fortran/arith.h	(working copy)
@@ -27,7 +27,7 @@ along with GCC; see the file COPYING3.  
 /* MPFR also does not have the conversion of a mpfr_t to a mpz_t, so declare
    a function for this as well.  */
 
-void gfc_mpfr_to_mpz (mpz_t, mpfr_t);
+void gfc_mpfr_to_mpz (mpz_t, mpfr_t, locus *);
 void gfc_set_model_kind (int);
 void gfc_set_model (mpfr_t);
 
Index: gcc/fortran/simplify.c
===================================================================
--- gcc/fortran/simplify.c	(revision 141346)
+++ gcc/fortran/simplify.c	(working copy)
@@ -808,7 +808,7 @@ gfc_simplify_ceiling (gfc_expr *e, gfc_e
   ceil = gfc_copy_expr (e);
 
   mpfr_ceil (ceil->value.real, e->value.real);
-  gfc_mpfr_to_mpz (result->value.integer, ceil->value.real);
+  gfc_mpfr_to_mpz (result->value.integer, ceil->value.real, &e->where);
 
   gfc_free_expr (ceil);
 
@@ -1341,7 +1341,7 @@ gfc_simplify_floor (gfc_expr *e, gfc_exp
   mpfr_init (floor);
   mpfr_floor (floor, e->value.real);
 
-  gfc_mpfr_to_mpz (result->value.integer, floor);
+  gfc_mpfr_to_mpz (result->value.integer, floor, &e->where);
 
   mpfr_clear (floor);
 
@@ -1925,7 +1925,7 @@ gfc_simplify_ifix (gfc_expr *e)
   rtrunc = gfc_copy_expr (e);
 
   mpfr_trunc (rtrunc->value.real, e->value.real);
-  gfc_mpfr_to_mpz (result->value.integer, rtrunc->value.real);
+  gfc_mpfr_to_mpz (result->value.integer, rtrunc->value.real, &e->where);
 
   gfc_free_expr (rtrunc);
   return range_check (result, "IFIX");
@@ -1946,7 +1946,7 @@ gfc_simplify_idint (gfc_expr *e)
   rtrunc = gfc_copy_expr (e);
 
   mpfr_trunc (rtrunc->value.real, e->value.real);
-  gfc_mpfr_to_mpz (result->value.integer, rtrunc->value.real);
+  gfc_mpfr_to_mpz (result->value.integer, rtrunc->value.real, &e->where);
 
   gfc_free_expr (rtrunc);
   return range_check (result, "IDINT");
@@ -2969,7 +2969,7 @@ simplify_nint (const char *name, gfc_exp
 
   mpfr_round (itrunc->value.real, e->value.real);
 
-  gfc_mpfr_to_mpz (result->value.integer, itrunc->value.real);
+  gfc_mpfr_to_mpz (result->value.integer, itrunc->value.real, &e->where);
 
   gfc_free_expr (itrunc);
 

Re: [PATCH] fortran/37930 -- Fix clever user trick

[Mikael Morin]

Nothing to say about the patch but a little typo:

+  if (mpfr_inf_p (x) || mpfr_nan_p (x))
+	{
 ^^^^^^^  <TAB> here
+      gfc_error ("Conversion of exceptional value at %L", where);

Re: [PATCH] fortran/37930 -- Fix clever user trick

[Steve Kargl]

On Tue, Oct 28, 2008 at 02:33:32PM +0100, Mikael Morin wrote:
> Nothing to say about the patch but a little typo:
> 
> +  if (mpfr_inf_p (x) || mpfr_nan_p (x))
> +	{
>  ^^^^^^^  <TAB> here
> +      gfc_error ("Conversion of exceptional value at %L", where);

Whoops.  I had tabstop=4 in .exrc, which of course looks like 4 spaces.
 
-- 
Steve