gcc47: _GLIBCXX_DEBUG and empty ostringstream

[akimd (Akim Demaille)]

Hi,

The following program fails on Mac OS X with both 4.7 and 4.8.

$ uname -a
Darwin padam.local 11.4.0 Darwin Kernel Version 11.4.0: Mon Apr  9 19:32:15 PDT 2012; root:xnu-1699.26.8~1/RELEASE_X86_64 x86_64

$ g++-mp-4.7 --version
g++-mp-4.7 (MacPorts gcc47 4.7.1_0) 4.7.1
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ g++-mp-4.8 --version
g++-mp-4.8 (MacPorts gcc48 4.8-20120701_0) 4.8.0 20120701 (experimental)
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ cat simpleaut.cc
# define _GLIBCXX_DEBUG 1
# include <sstream>

int main()
{
  std::ostringstream s;
  s.str();
}

$ g++-mp-4.7 tests/unit/simpleaut.cc
Using built-in specs.
COLLECT_GCC=g++-mp-4.7
COLLECT_LTO_WRAPPER=/opt/local/libexec/gcc/x86_64-apple-darwin11/4.7.1/lto-wrapper
Target: x86_64-apple-darwin11
Configured with: ../gcc-4.7.1/configure --prefix=/opt/local --build=x86_64-apple-darwin11 --enable-languages=c,c++,objc,obj-c++,lto,fortran,java --libdir=/opt/local/lib/gcc47 --includedir=/opt/local/include/gcc47 --infodir=/opt/local/share/info --mandir=/opt/local/share/man --datarootdir=/opt/local/share/gcc-4.7 --with-libiconv-prefix=/opt/local --with-local-prefix=/opt/local --with-system-zlib --disable-nls --program-suffix=-mp-4.7 --with-gxx-include-dir=/opt/local/include/gcc47/c++/ --with-gmp=/opt/local --with-mpfr=/opt/local --with-mpc=/opt/local --with-ppl=/opt/local --with-cloog=/opt/local --enable-cloog-backend=isl --enable-stage1-checking --disable-multilib --enable-lto --with-as=/opt/local/bin/as --with-ld=/opt/local/bin/ld --with-ar=/opt/local/bin/ar --with-bugurl=https://trac.macports.org/newticket --with-pkgversion='MacPorts gcc47 4.7.1_0'
Thread model: posix
gcc version 4.7.1 (MacPorts gcc47 4.7.1_0) 
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.7.4' '-v' '-shared-libgcc' '-mtune=core2'
 /opt/local/libexec/gcc/x86_64-apple-darwin11/4.7.1/cc1plus -quiet -v -D__DYNAMIC__ foo.cc -fPIC -quiet -dumpbase foo.cc -mmacosx-version-min=10.7.4 -mtune=core2 -auxbase foo -version -o /var/folders/vc/vkjp1hhs5dgg8blcpzm6t59c0000gp/T//ccDjHKgh.s
GNU C++ (MacPorts gcc47 4.7.1_0) version 4.7.1 (x86_64-apple-darwin11)
	compiled by GNU C version 4.7.1, GMP version 5.0.4, MPFR version 3.1.0-p3, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/4.7.1/../../../../../x86_64-apple-darwin11/include"
ignoring duplicate directory "/opt/local/include"
  as it is a non-system directory that duplicates a system directory
#include "..." search starts here:
#include <...> search starts here:
 /opt/local/include/gcc47/c++/
 /opt/local/include/gcc47/c++//x86_64-apple-darwin11
 /opt/local/include/gcc47/c++//backward
 /opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/4.7.1/include
 /opt/local/include
 /opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/4.7.1/include-fixed
 /usr/include
 /System/Library/Frameworks
 /Library/Frameworks
End of search list.
GNU C++ (MacPorts gcc47 4.7.1_0) version 4.7.1 (x86_64-apple-darwin11)
	compiled by GNU C version 4.7.1, GMP version 5.0.4, MPFR version 3.1.0-p3, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 09950ee4f031f09244f876c6af55ed8f
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.7.4' '-v' '-shared-libgcc' '-mtune=core2'
 /opt/local/bin/as -v -arch x86_64 -force_cpusubtype_ALL -o /var/folders/vc/vkjp1hhs5dgg8blcpzm6t59c0000gp/T//cc5KozFj.o /var/folders/vc/vkjp1hhs5dgg8blcpzm6t59c0000gp/T//ccDjHKgh.s
Apple Inc version cctools-822, GNU assembler version 1.38
COMPILER_PATH=/opt/local/libexec/gcc/x86_64-apple-darwin11/4.7.1/:/opt/local/libexec/gcc/x86_64-apple-darwin11/4.7.1/:/opt/local/libexec/gcc/x86_64-apple-darwin11/:/opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/4.7.1/:/opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/
LIBRARY_PATH=/opt/local/lib/:/opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/4.7.1/:/opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/4.7.1/../../../:/usr/lib/
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.7.4' '-v' '-shared-libgcc' '-mtune=core2'
 /opt/local/libexec/gcc/x86_64-apple-darwin11/4.7.1/collect2 -dynamic -arch x86_64 -macosx_version_min 10.7.4 -weak_reference_mismatches non-weak -o a.out -lcrt1.10.6.o -L/opt/local/lib -L/opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/4.7.1 -L/opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/4.7.1/../../.. /var/folders/vc/vkjp1hhs5dgg8blcpzm6t59c0000gp/T//cc5KozFj.o -lstdc++ -no_compact_unwind -lSystem -lgcc_ext.10.5 -lgcc -lSystem -v
collect2 version 4.7.1
/opt/local/bin/ld -dynamic -arch x86_64 -macosx_version_min 10.7.4 -weak_reference_mismatches non-weak -o a.out -lcrt1.10.6.o -L/opt/local/lib -L/opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/4.7.1 -L/opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/4.7.1/../../.. /var/folders/vc/vkjp1hhs5dgg8blcpzm6t59c0000gp/T//cc5KozFj.o -lstdc++ -no_compact_unwind -lSystem -lgcc_ext.10.5 -lgcc -lSystem -v
@(#)PROGRAM:ld  PROJECT:ld64-128.2
Library search paths:
	/opt/local/lib
	/opt/local/lib/gcc47/gcc/x86_64-apple-darwin11/4.7.1
	/opt/local/lib/gcc47
	/usr/lib
	/usr/local/lib
Framework search paths:
	/Library/Frameworks/
	/System/Library/Frameworks/


$ ./a.out
a.out(28056) malloc: *** error for object 0x10a5f2340: pointer being freed was
not allocated
*** set a breakpoint in malloc_error_break to debug
zsh: abort      ./a.out


(gdb) bt
#0  0x00007fff89bf582a in __kill ()
#1  0x00007fff89833a9c in abort ()
#2  0x00007fff8989284c in free ()
#3  0x0000000100000b86 in __gnu_cxx::new_allocator<char>::deallocate
(this=0x7fff5fbff847, 
    __p=0x1000d0340 "") at ext/new_allocator.h:102
#4  0x0000000100000b58 in std::string::_Rep::_M_destroy (this=0x1000d0340, 
    __a=@0x7fff5fbff89f) at bits/basic_string.tcc:451
#5  0x0000000100000ae6 in std::string::_Rep::_M_dispose (this=0x1000d0340, 
    __a=@0x7fff5fbff89f) at bits/basic_string.h:251
#6  0x00000001000009fd in std::basic_string<char, std::char_traits<char>,
std::allocator<char> >::~basic_string (this=0x7fff5fbffa20) at
bits/basic_string.h:541
#7  0x0000000100000968 in main () at tests/unit/simpleaut.cc:7

Please, see the (wrong) bug report I made to the GCC team, where they emit ideas about the possible problem:

​http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53838

[mww@…]

compiling gcc 4.7 with --enable-fully-dynamic-string fails on 10.7; also when trying your example the resuling binary is linked to our gcc's C++-lib

[akimd (Akim Demaille)]

Well, what is the best course of action from now on? I suggest putting you in CC of the ticket at gcc.gnu.org, and interacting with them there. WDYT?

[akimd (Akim Demaille)]

I would like a clarification on

compiling gcc 4.7 with --enable-fully-dynamic-string fails on 10.7

you do mean that 4.7 cannot be compiled on 10.7 with --enable-fully-dynamic-string right? Not that my test case fails also with --enable-fully-dynamic-string.

[mww@…]

yes, adding "--enable-fully-dynamic-string" to the configure.args of Portfile of gcc47 makes it FAIL to compile on OS X 10.7. Did you mean that your test also fails or that it does not?

[akimd (Akim Demaille)]

Did you mean that your test also fails or that it does not?

Nope, I just meant to be sure that I could report to the GCC team that there is a problem with building GCC with --enable-fully-dynamic-string.

Do you have logs somewhere? Is there something to report to them about this failure?

[akimd (Akim Demaille)]

Well, it seems that we do have two different issues.

One is that GCC fails to build with --enable-fully-dynamic-string. As far as the GCC team knows, GCC builds fine on this architecture with --enable-fully-dynamic-string, so it must be something specific to the MacPorts. If there is really something about GCC per se, then the GCC team would like a specific ticket (all this is stated here: ​http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53838#c5).

The other problem is the one that I reported. With or without --enable-fully-dynamic-string, the test case I sent is expected to run properly, which is not the case on MacPorts. What would you like to know to get this bug fixed?

Thanks!

[rob.patro@…]

This bug still exists and, among other things, causes boost to fail in a number of cases.

Cc Me!

[barto@…]

Adding that g++-mp-4.8 also has this problem.

And it affects std::string as well.

ui3(2112) malloc: * error for object 0x100084f00: pointer being freed was not allocated * set a breakpoint in malloc_error_break to debug

Breakpoint 2, 0x00007fff97855588 in malloc_error_break ()

(gdb) where
#1  0x00007fff97856942 in free ()
#2  0x00000001063c1f3c in std::string::reserve ()
#3  0x0000010701620000 in ?? ()

Turning off the _GLIBCXX_DEBUG 'fixes' the issue. This is happening in my global constructors. So something in the MacPort version of the libstdc++ library is not working when turning on the debug flag for array bounds checking.