[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505 --- Comment #12 from Elizebeth Punnoose --- (In reply to kargl from comment #11) > Fixed on trunk. Closing. > > Elizebeth, Thanks for the patch. Thank you.
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505 kargl at gcc dot gnu.org changed: What|Removed |Added Status|NEW |RESOLVED Resolution|--- |FIXED Target Milestone|--- |7.0 --- Comment #11 from kargl at gcc dot gnu.org --- Fixed on trunk. Closing. Elizebeth, Thanks for the patch.
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505 --- Comment #10 from kargl at gcc dot gnu.org --- Author: kargl Date: Thu Dec 1 23:11:35 2016 New Revision: 243143 URL: https://gcc.gnu.org/viewcvs?rev=243143&root=gcc&view=rev Log: 2016-12-01 Elizebeth Punnoose PR fortran/77505 * trans-array.c (trans_array_constructor): Treat negative character length as LEN = 0. 2016-12-01 Elizebeth Punnoose PR fortran/77505 * gfortran.dg/char_length_20.f90: New test. * gfortran.dg/char_length_21.f90: Ditto. Added: trunk/gcc/testsuite/gfortran.dg/char_length_20.f90 trunk/gcc/testsuite/gfortran.dg/char_length_21.f90 Modified: trunk/gcc/fortran/ChangeLog trunk/gcc/fortran/trans-array.c trunk/gcc/testsuite/ChangeLog
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505
--- Comment #9 from Elizebeth Punnoose ---
(In reply to Janne Blomqvist from comment #8)
> (In reply to Elizebeth Punnoose from comment #6)
> > Modified code with the warning message moved behind -fcheck=bounds.
> >
> > Index: trans-array.c
> > ===
> > --- trans-array.c (revision 241960)
> > +++ trans-array.c (working copy)
> > @@ -2226,6 +2226,8 @@
> >gfc_ss_info *ss_info;
> >gfc_expr *expr;
> >gfc_ss *s;
> > + tree neg_len;
> > + char *msg;
> >
> >/* Save the old values for nested checking. */
> >old_first_len = first_len;
> > @@ -2271,6 +2273,27 @@
> > gfc_conv_expr_type (&length_se, expr->ts.u.cl->length,
> > gfc_charlen_type_node);
> > ss_info->string_length = length_se.expr;
> > +
> > + /* Check if the character length is negative,
> > +if so consider it as LEN=0. */
> > + neg_len = fold_build2_loc (input_location, LT_EXPR,
> > + boolean_type_node, ss_info->string_length,
> > + build_int_cst (gfc_charlen_type_node, 0));
> > + /* Print a warning if bounds checking is enabled. */
> > + if (gfc_option.rtcheck & GFC_RTCHECK_BOUNDS)
> > + {
> > + msg = xasprintf ("Negative character length will be treated as
> > LEN=0");
> > + gfc_trans_runtime_check (false, true, neg_len,
> > +&length_se.pre, where, msg);
> > + free(msg);
> > + }
> > + ss_info->string_length = fold_build3_loc (input_location,
> > + COND_EXPR, gfc_charlen_type_node,
> > + neg_len, gfc_index_zero_node,
> > + ss_info->string_length);
> > + ss_info->string_length = gfc_evaluate_now (ss_info->string_length,
> > +&length_se.pre);
> > +
> > gfc_add_block_to_block (&outer_loop->pre, &length_se.pre);
> > gfc_add_block_to_block (&outer_loop->post, &length_se.post);
> > }
>
>
> Shouldn't you have build_int_cst (gfc_charlen_type_node, 0) instead of
> gfc_index_zero_node?
Thank you for your comment. I will make the necessary changes and re-post.
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505
Janne Blomqvist changed:
What|Removed |Added
CC||jb at gcc dot gnu.org
--- Comment #8 from Janne Blomqvist ---
(In reply to Elizebeth Punnoose from comment #6)
> Modified code with the warning message moved behind -fcheck=bounds.
>
> Index: trans-array.c
> ===
> --- trans-array.c (revision 241960)
> +++ trans-array.c (working copy)
> @@ -2226,6 +2226,8 @@
>gfc_ss_info *ss_info;
>gfc_expr *expr;
>gfc_ss *s;
> + tree neg_len;
> + char *msg;
>
>/* Save the old values for nested checking. */
>old_first_len = first_len;
> @@ -2271,6 +2273,27 @@
> gfc_conv_expr_type (&length_se, expr->ts.u.cl->length,
> gfc_charlen_type_node);
> ss_info->string_length = length_se.expr;
> +
> + /* Check if the character length is negative,
> + if so consider it as LEN=0. */
> + neg_len = fold_build2_loc (input_location, LT_EXPR,
> + boolean_type_node, ss_info->string_length,
> + build_int_cst (gfc_charlen_type_node, 0));
> + /* Print a warning if bounds checking is enabled. */
> + if (gfc_option.rtcheck & GFC_RTCHECK_BOUNDS)
> + {
> + msg = xasprintf ("Negative character length will be treated as
> LEN=0");
> + gfc_trans_runtime_check (false, true, neg_len,
> + &length_se.pre, where, msg);
> + free(msg);
> + }
> + ss_info->string_length = fold_build3_loc (input_location,
> +COND_EXPR, gfc_charlen_type_node,
> +neg_len, gfc_index_zero_node,
> +ss_info->string_length);
> + ss_info->string_length = gfc_evaluate_now (ss_info->string_length,
> + &length_se.pre);
> +
> gfc_add_block_to_block (&outer_loop->pre, &length_se.pre);
> gfc_add_block_to_block (&outer_loop->post, &length_se.post);
> }
Shouldn't you have build_int_cst (gfc_charlen_type_node, 0) instead of
gfc_index_zero_node?
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505 --- Comment #7 from Elizebeth Punnoose --- I plan to send the patch to gcc-patches from my official mail id, in a couple of days. Please do let me know if there are any suggestions/comments.
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505
--- Comment #6 from Elizebeth Punnoose ---
Modified code with the warning message moved behind -fcheck=bounds.
Index: trans-array.c
===
--- trans-array.c (revision 241960)
+++ trans-array.c (working copy)
@@ -2226,6 +2226,8 @@
gfc_ss_info *ss_info;
gfc_expr *expr;
gfc_ss *s;
+ tree neg_len;
+ char *msg;
/* Save the old values for nested checking. */
old_first_len = first_len;
@@ -2271,6 +2273,27 @@
gfc_conv_expr_type (&length_se, expr->ts.u.cl->length,
gfc_charlen_type_node);
ss_info->string_length = length_se.expr;
+
+ /* Check if the character length is negative,
+if so consider it as LEN=0. */
+ neg_len = fold_build2_loc (input_location, LT_EXPR,
+ boolean_type_node, ss_info->string_length,
+ build_int_cst (gfc_charlen_type_node, 0));
+ /* Print a warning if bounds checking is enabled. */
+ if (gfc_option.rtcheck & GFC_RTCHECK_BOUNDS)
+ {
+ msg = xasprintf ("Negative character length will be treated as
LEN=0");
+ gfc_trans_runtime_check (false, true, neg_len,
+&length_se.pre, where, msg);
+ free(msg);
+ }
+ ss_info->string_length = fold_build3_loc (input_location,
+ COND_EXPR, gfc_charlen_type_node,
+ neg_len, gfc_index_zero_node,
+ ss_info->string_length);
+ ss_info->string_length = gfc_evaluate_now (ss_info->string_length,
+&length_se.pre);
+
gfc_add_block_to_block (&outer_loop->pre, &length_se.pre);
gfc_add_block_to_block (&outer_loop->post, &length_se.post);
}
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505 --- Comment #5 from Elizebeth Punnoose --- Hi Steve, To answer your first question, I am covered by the HPE corporate assignment. When posting the patch, I will be doing so from my corporate email id. The Fortran 2008 standards page at http://www.j3-fortran.org/doc/year/10/10-007.pdf, states the the following. 4.4.3.2 Character type specifier 5 If the character length parameter value evaluates to a negative value, the length of character entities declared is zero. I do agree with you that a negative character length does not indicate a violation of the standard, rather that it has to be considered as len=0, and hence does not warrant issuing a warning. The warning message can be hidden behind the -fcheck=bounds option.
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505 --- Comment #4 from Steve Kargl --- On Fri, Nov 11, 2016 at 04:49:49AM +, elizebethp at gmail dot com wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505 > > Elizebeth Punnoose changed: > Hi Elizebeth, Just an administrative question at the moment. Do you have a copyright assignment for GCC on file with the FSF? I need to review the standards, but if the standard state a negative length should be treated as if it is len=0 then the I think the warning message should be hidden behind a -fcheck= option. Perhaps, we can overload -fcheck=bounds or introduce a new option key -fcheck=charlen. My reason is that it can be annoying for standard conforming code to issue a warning for standard conforming behavior.
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505
Elizebeth Punnoose changed:
What|Removed |Added
CC||elizebethp at gmail dot com
--- Comment #3 from Elizebeth Punnoose ---
The segmentation fault is reproducible on x86 & ARM64, with the top of trunk.
I have now added a check in trans-array.c:trans_array_constructor()
to check for character lengths less than zero, for character arrays.
If the length is found to be negative, a warning message is printed that the
length will be considered as LEN=0, and the length is set to zero.
Index: trans-array.c
===
--- trans-array.c (revision 241960)
+++ trans-array.c (working copy)
@@ -2226,6 +2226,8 @@
gfc_ss_info *ss_info;
gfc_expr *expr;
gfc_ss *s;
+ tree neg_len;
+ char *msg;
/* Save the old values for nested checking. */
old_first_len = first_len;
@@ -2271,6 +2273,19 @@
gfc_conv_expr_type (&length_se, expr->ts.u.cl->length,
gfc_charlen_type_node);
ss_info->string_length = length_se.expr;
+
+ /* Check if the length is negative, if so print a warning
+ and consider the length as zero. */
+ neg_len = fold_build2_loc (input_location, LT_EXPR,
+ boolean_type_node,
+ ss_info->string_length, build_int_cst
(gfc_charlen_type_node, 0));
+ msg = xasprintf ("Negative character length will be treated as
LEN=0");
+ gfc_trans_runtime_check (false, true, neg_len, &length_se.pre,
where, msg);
+ free(msg);
+ ss_info->string_length = fold_build3_loc (input_location, COND_EXPR,
gfc_charlen_type_node,
+ neg_len, gfc_index_zero_node,
ss_info->string_length);
+ ss_info->string_length = gfc_evaluate_now (ss_info->string_length,
&length_se.pre);
+
gfc_add_block_to_block (&outer_loop->pre, &length_se.pre);
gfc_add_block_to_block (&outer_loop->post, &length_se.post);
}
The test suite has run clean with the above changes merged on top of trunk.
Kindly review and provide your suggestions if any.
I will post the patch on the gcc-patches mail list, if there is no objection.
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505 kargl at gcc dot gnu.org changed: What|Removed |Added Priority|P3 |P4 Severity|minor |normal
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505 --- Comment #2 from Steve Kargl --- On Wed, Sep 07, 2016 at 07:01:40PM +, kargl at gcc dot gnu.org wrote: > --- Comment #1 from kargl at gcc dot gnu.org --- > This is going to require someone smarting than I to fix. > The problem lies in trans-array.c (get_array_ctor_strlen). > This function walks the elments of the array constructor > looking for the string length. It nave takes into account > the type spec in [character(len=ii) :: ]. s/nave/never Note, the problem may actually be in some other function that calls get_array_ctor_strlen, because this function never have been called!
[Bug fortran/77505] Negative character length not treated as LEN=0
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77505 kargl at gcc dot gnu.org changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2016-09-07 CC||kargl at gcc dot gnu.org Ever confirmed|0 |1 --- Comment #1 from kargl at gcc dot gnu.org --- This is going to require someone smarting than I to fix. The problem lies in trans-array.c (get_array_ctor_strlen). This function walks the elments of the array constructor looking for the string length. It nave takes into account the type spec in [character(len=ii) :: ].
