http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56737
Bug #: 56737
Summary: Bizarre Hollerith edit descriptor errors (valgrind
shows uninitialized value in libgfortran)
Classification: Unclassified
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libfortran
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: jonathan.h...@stfc.ac.uk
Created attachment 29728
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29728
Code to reproduce bug
With the code attached I get junk output in a real program. Simplified version
below only shows errors under valgrind. Easy workaround by transforming code to
modern Fortran that doesn't use the h edit descriptor.
Yes, the byzantine subroutine hierarchy and unuser arguments appear to be
required to reproduce the bug.
Expected test-code behaviour: Should produce valgrind-clean code. Shuold
perhaps warn that 'h' edit descriptor is obsolescent/deleted (in F95+).
Expected real-code behaviour: Shouldn't produce garbage to output.
Thanks,
Jonathan.
$gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.7.2-4ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs
--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.7 --enable-shared --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object
--enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686
--with-tune=generic --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-4ubuntu1)
$gfortran -g -o gfort_bug gfort_bug.f90 && valgrind ./gfort_bug
==8437== Memcheck, a memory error detector
==8437== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==8437== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==8437== Command: ./gfort_bug
==8437==
fmt = ( 3(1H ),6h===== ,a 12,i4,6h =====)
title1= end of level
level = 1
===== end of level 1 =====
fmt = ( 3(1H ),6h===== ,a 12,i4,6h =====)
title1= end of level
level = 1
==8437== Conditional jump or move depends on uninitialised value(s)
==8437== at 0x4F0BB41: ??? (in
/usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
==8437== by 0x400B51: __hsl_mc73_single_MOD_level_print (gfort_bug.f90:56)
==8437== by 0x400B93: __hsl_mc73_single_MOD_multilevel_eig
(gfort_bug.f90:40)
==8437== by 0x400BB9: __hsl_mc73_single_MOD_fiedler_graph (gfort_bug.f90:33)
==8437== by 0x400BF9: __hsl_mc73_single_MOD_mc73_fiedler (gfort_bug.f90:17)
==8437== by 0x400C27: MAIN__ (gfort_bug.f90:71)
==8437== by 0x400C5D: main (gfort_bug.f90:62)
==8437==
==8437== Conditional jump or move depends on uninitialised value(s)
==8437== at 0x4F0BB1B: ??? (in
/usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
==8437== by 0x400B51: __hsl_mc73_single_MOD_level_print (gfort_bug.f90:56)
==8437== by 0x400B93: __hsl_mc73_single_MOD_multilevel_eig
(gfort_bug.f90:40)
==8437== by 0x400BB9: __hsl_mc73_single_MOD_fiedler_graph (gfort_bug.f90:33)
==8437== by 0x400BF9: __hsl_mc73_single_MOD_mc73_fiedler (gfort_bug.f90:17)
==8437== by 0x400C27: MAIN__ (gfort_bug.f90:71)
==8437== by 0x400C5D: main (gfort_bug.f90:62)
==8437==
==8437== Syscall param write(buf) points to uninitialised byte(s)
==8437== at 0x522C900: __write_nocancel (syscall-template.S:82)
==8437== by 0x4F0ECEC: ??? (in
/usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
==8437== by 0x4F1540E: ??? (in
/usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
==8437== by 0x4F0A726: ??? (in
/usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
==8437== by 0x4F0B008: _gfortran_st_write_done (in
/usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
==8437== by 0x400B60: __hsl_mc73_single_MOD_level_print (gfort_bug.f90:56)
==8437== by 0x400B93: __hsl_mc73_single_MOD_multilevel_eig
(gfort_bug.f90:40)
==8437== by 0x400BB9: __hsl_mc73_single_MOD_fiedler_graph (gfort_bug.f90:33)
==8437== by 0x400BF9: __hsl_mc73_single_MOD_mc73_fiedler (gfort_bug.f90:17)
==8437== by 0x400C27: MAIN__ (gfort_bug.f90:71)
==8437== by 0x400C5D: main (gfort_bug.f90:62)
==8437== Address 0x5c4fc3a is 26 bytes inside a block of size 512 alloc'd
==8437== at 0x4C2B3F8: malloc (in
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==8437== by 0x4E4D488: ??? (in
/usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
==8437== by 0x4F1529A: ??? (in
/usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
==8437== by 0x4F0E421: ??? (in
/usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
==8437== by 0x4E4AB67: ??? (in
/usr/lib/x86_64-linux-gnu/libgfortran.so.3.0.0)
==8437== by 0x400F315: call_init.part.0 (dl-init.c:85)
==8437== by 0x400F3EE: _dl_init (dl-init.c:52)
==8437== by 0x40016F9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==8437==
end of level 1 ====)
==8437==
==8437== HEAP SUMMARY:
==8437== in use at exit: 0 bytes in 0 blocks
==8437== total heap usage: 29 allocs, 29 frees, 24,709 bytes allocated
==8437==
==8437== All heap blocks were freed -- no leaks are possible
==8437==
==8437== For counts of detected and suppressed errors, rerun with: -v
==8437== Use --track-origins=yes to see where uninitialised values come from
==8437== ERROR SUMMARY: 11 errors from 3 contexts (suppressed: 2 from 2)
