[Bug libfortran/29101] New: memory leak in libgfortran

[Bug libfortran/29101] New: memory leak in libgfortran

[franke dot daniel at gmail dot com]

Please find below a stripped down testcase and a session log from valgrind.

The code reads input from stdin, compares what was read against a couple of
choices (exactly one in this case) and repeats reading until a single 'x' was
entered. The leak is related to the length of the input buffer within the main
program, hitting [enter] N times before giving an 'x' results in N leaked
blocks of strlen(input). Also involved is the SELECT CASE: if it is replaced by
an equivalent IF-statement, no memory is leaked.

Reproducible with gfortran-4.1.1 and gfortran-4.2 20060914 (experimental).

$> cat test.f90
MODULE stringutils
CHARACTER(*), PRIVATE, PARAMETER :: lowercase = 'abcdefghijklmnopqrstuvwxyz' 
CHARACTER(*), PRIVATE, PARAMETER :: uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 
CONTAINS
  FUNCTION tolower(instr) RESULT (outstr)
    CHARACTER(len=*), INTENT(in) :: instr
    CHARACTER(len=len(instr))    :: outstr
    INTEGER :: i, k
    outstr = instr
    DO i = 1, len_trim(outstr)
      k = index(uppercase, outstr(i:i))
      if (k /= 0) outstr(i:i) = lowercase(k:k)
    END DO
  END FUNCTION
END MODULE

MODULE configuration
CONTAINS
  LOGICAL FUNCTION validate_value(input, value)
    USE stringutils
    CHARACTER(len=*), INTENT(in) :: input
    INTEGER, INTENT(out)         :: value
    validate_value = .TRUE.
    SELECT CASE (tolower(input))
      CASE ("x");  value = 1
      CASE DEFAULT
        validate_value = .FALSE.
    END SELECT
  END FUNCTION
END MODULE

PROGRAM test
  USE configuration
  USE stringutils
  INTEGER             :: value
  CHARACTER(len=256)  :: input
  DO 
    WRITE (*, FMT="(A)", ADVANCE = "NO") "$> "
    READ (*, FMT="(A)") input
    IF (validate_value(input, value)) EXIT
  END DO
END PROGRAM

$> gfortran-4.2 -g -Wall test.f90
$> valgrind --tool=memcheck --leak-check=full ./a.out
==9829== Memcheck, a memory error detector.
==9829== Copyright (C) 2002-2006, and GNU GPL'd, by Julian Seward et al.
==9829== Using LibVEX rev 1606, a library for dynamic binary translation.
==9829== Copyright (C) 2004-2006, and GNU GPL'd, by OpenWorks LLP.
==9829== Using valgrind-3.2.0, a dynamic binary instrumentation framework.
==9829== Copyright (C) 2000-2006, and GNU GPL'd, by Julian Seward et al.
==9829== For more details, rerun with: -v
==9829==
%>
%>
%>
%>
%>
%> x
==9829==
==9829== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 3 from 1)
==9829== malloc/free: in use at exit: 1,536 bytes in 6 blocks.
==9829== malloc/free: 24 allocs, 18 frees, 55,080 bytes allocated.
==9829== For counts of detected errors, rerun with: -v
==9829== searching for pointers to 6 not-freed blocks.
==9829== checked 78,156 bytes.
==9829==
==9829== 1,536 bytes in 6 blocks are definitely lost in loss record 1 of 1
==9829==    at 0x4021396: malloc (vg_replace_malloc.c:149)
==9829==    by 0x40304EC: _gfortrani_get_mem (memory.c:53)
==9829==    by 0x80488FA: __configuration__validate_value (dump.f90:29)
==9829==    by 0x8048A9A: MAIN__ (dump.f90:47)
==9829==    by 0x8048AD6: main (fmain.c:18)
==9829==
==9829== LEAK SUMMARY:
==9829==    definitely lost: 1,536 bytes in 6 blocks.
==9829==      possibly lost: 0 bytes in 0 blocks.
==9829==    still reachable: 0 bytes in 0 blocks.
==9829==         suppressed: 0 bytes in 0 blocks.
==9829== Reachable blocks (those to which a pointer was found) are not shown.
==9829== To see them, rerun with: --show-reachable=yes


-- 
           Summary: memory leak in libgfortran
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libfortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: franke dot daniel at gmail dot com
  GCC host triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug libfortran/29101] memory leak in libgfortran

[jvdelisle at gcc dot gnu dot org]

------- Comment #1 from jvdelisle at gcc dot gnu dot org  2006-09-16 01:28 -------
Confirmed: As can be seen here.  We are allocating, but not freeing pstr.6

  {
    char[1:D.960] * pstr.6;
    int4 D.960;
    int4 D.959;
    char[1:_input] & D.958;
    static struct _jump_struct jumptable.5[2] = {{.string1=0B, .string1_len=0,
.string2=0B, .string2_len=0, .target=&L.3}, {.string1="x", .string1_len=1,
.string2="x", .string2_len=1, .target=&L.4}};

    D.958 = input;
    D.959 = _input;
    D.960 = D.959;
    pstr.6 = (char[1:D.960] *) _gfortran_internal_malloc (D.960);
    tolower (pstr.6, D.960, D.958, D.959);
    goto _gfortran_select_string ((void *) &jumptable.5, 2, &L.5, pstr.6,
D.960);
    L.4:;
    *value = 1;
    goto L.5;
    L.3:;
    __result_validate_value = 0;
    goto L.5;
    L.5:;
  }
  return __result_validate_value;


-- 

jvdelisle 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         |2006-09-16 01:28:58
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[jvdelisle at gcc dot gnu dot org]

------- Comment #2 from jvdelisle at gcc dot gnu dot org  2006-09-17 20:14 -------
Problem is not in library side.


-- 

jvdelisle at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|libfortran                  |fortran
            Summary|memory leak in libgfortran  |Memory leak in gfortran


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[pault at gcc dot gnu dot org]

------- Comment #3 from pault at gcc dot gnu dot org  2006-09-18 06:53 -------
(In reply to comment #2)
> Problem is not in library side.
> 
Jerry,

This is an easy one: Somebody forgot to add the post block for the evaluation
of the select expression to the block of code, for the specific case of
character expressions.

This

Index: gcc/fortran/trans-stmt.c
===================================================================
*** gcc/fortran/trans-stmt.c    (revision 117013)
--- gcc/fortran/trans-stmt.c    (working copy)
*************** gfc_trans_character_select (gfc_code *co
*** 1467,1472 ****
--- 1467,1474 ----
    tmp = build1 (GOTO_EXPR, void_type_node, tmp);
    gfc_add_expr_to_block (&block, tmp);

+   gfc_add_block_to_block (&block, &se.post);
+
    tmp = gfc_finish_block (&body);
    gfc_add_expr_to_block (&block, tmp);
    tmp = build1_v (LABEL_EXPR, end_label);

fixes it by producing the code:

    pstr.6 = (char[1:D.960] *) _gfortran_internal_malloc (D.960);
    tolower (pstr.6, D.960, D.958, D.959);
    goto _gfortran_select_string ((void *) &jumptable.5, 2, &L.5, pstr.6,
D.960);
    _gfortran_internal_free ((void *) pstr.6);
    L.4:;
    *value = 1;
    goto L.5;
    L.3:;
    __result_validate_value = 0;
    goto L.5;
    L.5:;

I am not going to be in a position to do anything about this for two weeks -
"I'm on the road again...". I can submit it today; if it is determined to be
essential to get into the 4.2 release, could you do the honors with the commit?

Are there any more such constructs in fortran that take a character expression?
 I could not immediately think of any.

Paul


-- 

pault at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[pault at gcc dot gnu dot org]

-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |pault at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2006-09-16 01:28:58         |2006-09-18 07:49:56
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[patchapp at dberlin dot org]

------- Comment #4 from patchapp at dberlin dot org  2006-09-18 17:15 -------
Subject: Bug number PR29101

A patch for this bug has been added to the patch tracker.
The mailing list url for the patch is
http://gcc.gnu.org/ml/gcc-patches/2006-09/msg00715.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[pault at gcc dot gnu dot org]

------- Comment #5 from pault at gcc dot gnu dot org  2006-09-18 19:29 -------
Thanks Steven, it was just too obvious, wasn't it?

Index: gcc/fortran/trans-stmt.c
===================================================================
--- gcc/fortran/trans-stmt.c    (revision 117030)
+++ gcc/fortran/trans-stmt.c    (working copy)
@@ -1475,6 +1475,8 @@
   if (n != 0)
     gfc_free (labels);

+  gfc_add_block_to_block (&block, &se.post);
+
   return gfc_finish_block (&block);

now gives


    pstr.6 = (char[1:D.960] *) _gfortran_internal_malloc (D.960);
    tolower (pstr.6, D.960, D.958, D.959);
    goto _gfortran_select_string ((void *) &jumptable.5, 2, &L.5, pstr.6,
D.960);
    L.4:;
    *value = 1;
    goto L.5;
    L.3:;
    __result_validate_value = 0;
    goto L.5;
    L.5:;
    _gfortran_internal_free ((void *) pstr.6);


-- 

pault at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |stevenb dot gcc at gmail dot
                   |                            |com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[pault at gcc dot gnu dot org]

------- Comment #6 from pault at gcc dot gnu dot org  2006-09-18 20:20 -------
Subject: Bug 29101

Author: pault
Date: Mon Sep 18 20:19:50 2006
New Revision: 117034

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=117034
Log:
2006-09-18 Paul Thomas <pault@gcc.gnu.org>

        PR fortran/28526
        * primary.c (match_variable): If the compiler is in a module
        specification block, an interface block or a contains section,
        reset host_flag to force the changed symbols mechanism.

        PR fortran/29101
        * trans-stmt.c (gfc_trans_character_select): Add the post block
        for the expression to the main block, after the call to
        select_string and the last label.


2006-09-18 Paul Thomas <pault@gcc.gnu.org>

        PR fortran/28526
        * gfortran.dg/keyword_symbol_1.f90: New test.

        * gfortran.dg/spread_shape_1.f90: Add missing warning with
        pedantic compilation option.

Added:
    trunk/gcc/testsuite/gfortran.dg/keyword_symbol_1.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/primary.c
    trunk/gcc/fortran/trans-stmt.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gfortran.dg/spread_shape_1.f90


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[pault at gcc dot gnu dot org]

------- Comment #7 from pault at gcc dot gnu dot org  2006-09-18 22:24 -------
Fixed on trunk and 4.1

Paul


-- 

pault at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[steven at gcc dot gnu dot org]

------- Comment #8 from steven at gcc dot gnu dot org  2006-09-18 22:35 -------
Not fixed just yet.


-- 

steven at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[pault at gcc dot gnu dot org]

------- Comment #9 from pault at gcc dot gnu dot org  2006-09-19 11:05 -------
Subject: Bug 29101

Author: pault
Date: Tue Sep 19 11:04:55 2006
New Revision: 117053

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=117053
Log:
2006-09-19 Paul Thomas <pault@gcc.gnu.org>
           Steven Bosscher  <steven@gcc.gnu.org>

        PR fortran/29101
        * trans-stmt.c (gfc_trans_character_select): Store the label
        from select_string and then clean up any temporaries from the
        conversion of the select expression, before branching to the
        selected case.


Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/trans-stmt.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[pault at gcc dot gnu dot org]

------- Comment #10 from pault at gcc dot gnu dot org  2006-09-19 11:24 -------
Subject: Bug 29101

Author: pault
Date: Tue Sep 19 11:24:44 2006
New Revision: 117054

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=117054
Log:
2006-09-19 Paul Thomas <pault@gcc.gnu.org>
           Steven Bosscher  <steven@gcc.gnu.org>

        PR fortran/29101
        * trans-stmt.c (gfc_trans_character_select): Store the label
        from select_string and then clean up any temporaries from the
        conversion of the select expression, before branching to the
        selected case.


Modified:
    branches/gcc-4_1-branch/gcc/fortran/ChangeLog
    branches/gcc-4_1-branch/gcc/fortran/trans-stmt.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[pault at gcc dot gnu dot org]

------- Comment #11 from pault at gcc dot gnu dot org  2006-09-19 11:26 -------
Thanks to Steven's intervention, I can declare this bug well and truly closed.

Paul


-- 

pault at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101

[Bug fortran/29101] Memory leak in gfortran

[paulthomas2 at wanadoo dot fr]

------- Comment #12 from paulthomas2 at wanadoo dot fr  2006-09-19 11:56 -------
Subject: Re:  Memory leak in gfortran

steven at gcc dot gnu dot org wrote:

>------- Comment #8 from steven at gcc dot gnu dot org  2006-09-18 22:35 -------
>Not fixed just yet.
>
>
>  
>
Steven, I put it to rights this time.  Thanks for your help.  Can I lean 
on you in future, please?  I have been talking to myself of late.

Paul


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29101