[Bug fortran/35732] New: -fbounds-check: LHS/RHS size mismatch: Misleading error message

[Bug fortran/35732] New: -fbounds-check: LHS/RHS size mismatch: Misleading error message

[burnus at gcc dot gnu dot org]

For

integer :: a(2)
integer, volatile :: i
i = 1
 a(1:i) = a(1:2)
end

The message is misleading:

At line 4 of file aa.f90
Fortran runtime error: Array bound mismatch, size mismatch for dimension 1 of
array 'a' (0/1)

ISSUE:
  The size should be "1/2" and not "0/1" (For a zero-sized array the output is
even "-1").


-- 
           Summary: -fbounds-check: LHS/RHS size mismatch: Misleading error
                    message
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org
OtherBugsDependingO 27766
             nThis:


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732

[Bug fortran/35732] -fbounds-check: LHS/RHS size mismatch: Misleading error message

[fxcoudert at gcc dot gnu dot org]

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fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2008-04-06 12:42:30
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732

[Bug fortran/35732] -fbounds-check: LHS/RHS size mismatch: Misleading error message

[dfranke at gcc dot gnu dot org]

------- Comment #1 from dfranke at gcc dot gnu dot org  2009-01-03 23:52 -------
*** Bug 36029 has been marked as a duplicate of this bug. ***


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dfranke at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fxcoudert at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732

[Bug fortran/35732] -fbounds-check: LHS/RHS size mismatch: Misleading error message

[dominiq at lps dot ens dot fr]

------- Comment #2 from dominiq at lps dot ens dot fr  2009-04-26 19:53 -------
PR39872 is probably a duplicate of this PR.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732

[Bug fortran/35732] -fbounds-check: LHS/RHS size mismatch: Misleading error message

[dominiq at lps dot ens dot fr]

------- Comment #3 from dominiq at lps dot ens dot fr  2009-04-26 21:32 -------
The following patch seems to fix the PR (not fully tested yet):

--- ../_gcc_clean/gcc/fortran/trans-array.c     2009-04-20 13:44:15.000000000
+0200
+++ gcc/fortran/trans-array.c   2009-04-26 23:24:12.000000000 +0200
@@ -3249,8 +3249,10 @@ gfc_conv_ss_startstride (gfc_loopinfo * 
                }

              /* Check the section sizes match.  */
-             tmp = fold_build2 (MINUS_EXPR, gfc_array_index_type, end,
-                                info->start[n]);
+              tmp = fold_build2 (MINUS_EXPR, gfc_array_index_type,
+                                gfc_index_one_node, info->start[n]);
+             tmp = fold_build2 (PLUS_EXPR, gfc_array_index_type,
+                                end, tmp);
              tmp = fold_build2 (FLOOR_DIV_EXPR, gfc_array_index_type, tmp,
                                 info->stride[n]);
              tmp = fold_build2 (MAX_EXPR, gfc_array_index_type, tmp,

One thing I don't understand is why "fold_convert (long_integer_type_node,
size[n])" is magically updated. With the patch I get:

[ibook-dhum] f90/bug% gfc -fcheck=all pr35732.f90
[ibook-dhum] f90/bug% a.out 
At line 4 of file pr35732.f90
Fortran runtime error: Array bound mismatch, size mismatch for dimension 1 of
array 'a' (1/2)
[ibook-dhum] f90/bug% gfc -fcheck=all pr39872.f90
[ibook-dhum] f90/bug% a.out
At line 7 of file pr39872.f90
Fortran runtime error: Array bound mismatch, size mismatch for dimension 1 of
array 'a' (4/5)


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732

[Bug fortran/35732] -fbounds-check: LHS/RHS size mismatch: Misleading error message

[burnus at gcc dot gnu dot org]

------- Comment #4 from burnus at gcc dot gnu dot org  2009-04-26 21:51 -------
*** Bug 39872 has been marked as a duplicate of this bug. ***


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732

[Bug fortran/35732] -fbounds-check: LHS/RHS size mismatch: Misleading error message

[dominiq at lps dot ens dot fr]

------- Comment #5 from dominiq at lps dot ens dot fr  2009-04-27 06:32 -------
The patch in comment #3 works only for a stride equal to one -> some failures
in the test suite.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732

[Bug fortran/35732] -fbounds-check: LHS/RHS size mismatch: Misleading error message

[dominiq at lps dot ens dot fr]

------- Comment #6 from dominiq at lps dot ens dot fr  2009-04-27 08:20 -------
I think the right patch is:

--- ../_gcc_clean/gcc/fortran/trans-array.c     2009-04-20 13:44:15.000000000
+0200
+++ gcc/fortran/trans-array.c   2009-04-27 09:38:58.000000000 +0200
@@ -3253,6 +3253,8 @@ gfc_conv_ss_startstride (gfc_loopinfo * 
                                 info->start[n]);
              tmp = fold_build2 (FLOOR_DIV_EXPR, gfc_array_index_type, tmp,
                                 info->stride[n]);
+             tmp = fold_build2 (PLUS_EXPR, gfc_array_index_type,
+                                gfc_index_one_node, tmp);
              tmp = fold_build2 (MAX_EXPR, gfc_array_index_type, tmp,
                                 build_int_cst (gfc_array_index_type, 0));
              /* We remember the size of the first section, and check all the

Is a comment really needed? I have manually tested the failures seen with the
patch in comment #3 and they all pass now except
gfortran.dg/bounds_check_14.f90 which gives

[ibook-dhum] f90/bug% gfc -fbounds-check
/opt/gcc/_gcc_clean/gcc/testsuite/gfortran.dg/bounds_check_14.f90
[ibook-dhum] f90/bug% a.out 
At line 21 of file
/opt/gcc/_gcc_clean/gcc/testsuite/gfortran.dg/bounds_check_14.f90
Fortran runtime error: Array bound mismatch, size mismatch for dimension 1 of
array 'xca' (1/0)

Line 21 is

xca(1:1) = xda(1:2:mf3)

and I think the diagnostic is now correct (mf3==-3 or -1) and I don't
understand how the test is supposed to work:

if size(xda(1:2:mf3)) == 0, as checked by a later test, how can xca take the
value -1?

What ma I missing?

Also I'd be interested by ideas about test cases for this PR.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732

[Bug fortran/35732] -fbounds-check: LHS/RHS size mismatch: Misleading error message

[dominiq at lps dot ens dot fr]

------- Comment #7 from dominiq at lps dot ens dot fr  2009-04-28 12:48 -------
Posted a full patch at http://gcc.gnu.org/ml/fortran/2009-04/msg00283.html.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732

[Bug fortran/35732] -fbounds-check: LHS/RHS size mismatch: Misleading error message

[jvdelisle at gcc dot gnu dot org]

------- Comment #8 from jvdelisle at gcc dot gnu dot org  2009-05-25 03:07 -------
Subject: Bug 35732

Author: jvdelisle
Date: Mon May 25 03:07:00 2009
New Revision: 147842

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=147842
Log:
2009-05-24  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
            Dominique Dhumieres

        PR fortran/35732
        PR fortran/39872
        * trans-array.c (gfc_conv_ss_startstride): Add one to index.
        * gfortran.dg/bounds_check_fail_3.f90: New test.
        * gfortran.dg/bounds_check_fail_4.f90: New test.
        * gfortran.dg/bounds_check_14.f90: Update test.
        * gfortran.dg/bound_4.f90: Update test.

Added:
    trunk/gcc/testsuite/gfortran.dg/bounds_check_fail_3.f90
    trunk/gcc/testsuite/gfortran.dg/bounds_check_fail_4.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/trans-array.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/bound_4.f90
    trunk/gcc/testsuite/gfortran.dg/bounds_check_14.f90


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732

[Bug fortran/35732] -fbounds-check: LHS/RHS size mismatch: Misleading error message

[dominiq at lps dot ens dot fr]

------- Comment #9 from dominiq at lps dot ens dot fr  2009-08-22 22:07 -------
Should not this PR be closed as FIXED?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732

[Bug fortran/35732] -fbounds-check: LHS/RHS size mismatch: Misleading error message

[burnus at gcc dot gnu dot org]

------- Comment #10 from burnus at gcc dot gnu dot org  2009-08-23 08:54 -------
Close as FIXED. Part is fixed in 4.4 (cf. PR 39872), part only on the 4.5
trunk, but for a diagnostic off-by-one bug backporting to 4.4 is not really
worth.


-- 

burnus at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35732