Linux Today: Linux News On Internet Time.

More on LinuxToday

Release Digest: GNU, June 20, 2004

Jun 21, 2004, 05:00 (0 Talkback[s])

GDB 6.1.1

GDB 6.1.1 released!

Version 6.1.1 of GDB, the GNU Debugger, is now available via anonymous FTP. GDB is a source-level debugger for C, C++, Pascal, Objective-C and many other languages. GDB can target (i.e., debug programs running on) more than a dozen different processor architectures, and GDB itself can run on most popular GNU/Linux, Unix and Microsoft Windows variants.

You can download GDB from Project GNU's FTP server in the directory:

The previous version, 6.1, was released roughly 2 months ago; and in that time several new features have been added and many bugs have been fixed. The details are below. In addition, a number of late breaking problems have been identified and they are also mentioned below.

The vital stats:

Size md5sum Name
16704501 64cbef11992238ed154cc13c953491d0 gdb-6.1.1.tar.gz
12586670 dd25473f61a3a2e1b08dee5f67ebae28 gdb-6.1.1.tar.bz2

There is a web page for GDB at:

That page includes information about GDB mailing lists (an announcement mailing list, developers discussion lists, etc.), details on how to access GDB's CVS repository, locations for development snapshots, preformatted documentation, and links to related information around the net. We will put errata notes and host-specific tips for this release on-line as any problems come up. All mailing lists archives are also browsable via the web.

The credit must go to Shrinivas Atre, Jim Blandy, Joel Brobecker, Paul Brook, Kevin Buettner, David Carlton, Stephane Carrez, Michael Elizabeth Chastain, Albert Chin-A-Young, Randolph Chung, Stephen Clarke, Nick Clifton, Brendan Conoboy, Chris Demetriou, Dhananjay Deshpande, Ben Elliston, Christopher Faylor, Adam Fedor, Fred Fish, Orjan Friberg, Anthony Green, Jerome Guitton, Richard Henderson, Paul N. Hilfinger, Jim Ingham, Bernardo Innocenti, Daniel Jacobowitz, Andreas Jaeger, Jeff Johnston, Nick Kelsey, Mark Kettenis, David Lecomber, H.J. Lu, Michal Ludvig, Roland McGrath, Bryce McKinlay, Jason Merrill, Robert Millan, David S. Miller, Mark Mitchell, Alan Modra, Jason Molenda, David Mosberger, Atsushi Nemoto, Mark Newman, Rainer Orth, Pawel Ostrowski, Nick Roberts, Theodore A. Roth, Kei Sakamoto, Richard Sandiford, Peter Schauer, Andreas Schwab, Michael Snyder, Ian Lance Taylor, Corinna Vinschen, Kris Warkentin, Ulrich Weigand, James E Wilson, Jimi Xenidis, Elena Zannoni, and Eli Zaretskii along with all our testers and uses that who all contributed to the 6.1 release series.

Keep those fixes and improvements coming in! (See

Andrew Cagney
on behalf of the GDB Developers.

  • Changes in GDB 6.1.1:
    • TUI (Text-mode User Interface) built-in (also included in GDB 6.1)

      The TUI (Text-mode User Interface) is now built as part of a default GDB configuration. It is enabled by either selecting the TUI with the command line option "-i=tui" or by running the separate "gdbtui" program. For more information on the TUI, see the manual "Debugging with GDB".

    • Pending breakpoint support (also included in GDB 6.1)

      Support has been added to allow you to specify breakpoints in shared libraries that have not yet been loaded. If a breakpoint location cannot be found, and the "breakpoint pending" option is set to auto, GDB queries you if you wish to make the breakpoint pending on a future shared-library load. If and when GDB resolves the breakpoint symbol, the pending breakpoint is removed as one or more regular breakpoints are created.

      Pending breakpoints are very useful for GCJ Java debugging.

    • Fixed ISO-C build problems

      The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained non ISO-C code that stopped them being built using a more strict ISO-C compiler (e.g., IBM's C compiler).

    • Fixed build problem on IRIX 5

      Due to header problems with <sys/proc.h>, the file gdb/proc-api.c wasn't able to compile compile on an IRIX 5 system.

    • Added execute permission to gdb/gdbserver/configure

      The shell script gdb/testsuite/gdb.stabs/configure lacked execute permission. This bug would cause configure to fail on a number of systems (Solaris, IRIX). Ref: server/519.

    • Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler

      Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c has been updated to use constant array sizes.

    • Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7

      GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in its generated DWARF Call Frame Info. This encoding was causing GDB to panic, that panic has been fixed. Ref: gdb/1628.

    • Fixed a problem when examining parameters in shared library code.

      When examining parameters in optimized shared library code generated by a mainline GCC, GDB would incorrectly report ``Variable "..." is not available''. GDB now correctly displays the variable's value.

  • Changes in GDB 6.1:
    • Removed --with-mmalloc

      Support for the mmalloc memory manager has been removed, as it conflicted with the internal gdb byte cache.

    • Changes in AMD64 configurations

      The AMD64 target now includes the %cs and %ss registers. As a result the AMD64 remote protocol has changed; this affects the floating-point and SSE registers. If you rely on those registers for your debugging, you should upgrade gdbserver on the remote side.

    • Revised SPARC target

      The SPARC target has been completely revised, incorporating the FreeBSD/sparc64 support that was added for GDB 6.0. As a result support for LynxOS and SunOS 4 has been dropped. Calling functions from within GDB on operating systems with a non-executable stack (Solaris, OpenBSD) now works.

    • New C++ demangler

      GDB has a new C++ demangler which does a better job on the mangled names generated by current versions of g++. It also runs faster, so with this and other changes gdb should now start faster on large C++ programs.

    • DWARF 2 Location Expressions

      GDB support for location expressions has been extended to support function arguments and frame bases. Older versions of GDB could crash when they encountered these.

    • C++ nested types and namespaces

      GDB's support for nested types and namespaces in C++ has been improved, especially if you use the DWARF 2 debugging format. (This is the default for recent versions of GCC on most platforms.) Specifically, if you have a class "Inner" defined within a class or namespace "Outer", then GDB realizes that the class's name is "Outer::Inner", not simply "Inner". This should greatly reduce the frequency of complaints about not finding RTTI symbols. In addition, if you are stopped at inside of a function defined within a namespace, GDB modifies its name lookup accordingly.

    • New native configurations
      NetBSD/amd64 x86_64-*-netbsd*
      OpenBSD/amd64 x86_64-*-openbsd*
      OpenBSD/alpha alpha*-*-openbsd*
      OpenBSD/sparc sparc-*-openbsd*
      OpenBSD/sparc64 sparc64-*-openbsd*
    • New debugging protocols

      M32R with SDI protocol

      Known problems in GDB 6.1.1

      See also:

      Build problems

      build/1458: comple failed on hpux11

      GDB 6.1 is known to have build problems on HP/UX 11.00 using the vendor supplied compilers (GDB does build on HP/UX 11.11, and using GCC).


      gdb/1560: Control-C does not always interrupt GDB.

      When GDB is busy processing a command which takes a long time to complete, hitting Control-C does not have the expected effect. The command execution is not aborted, and the "QUIT" message confirming the abortion is displayed only after the command has been completed.

      C++ support

      gdb/931: GDB could be more generous when reading types C++ templates on input

      When the user types a template, GDB frequently requires the type to be typed in a certain way (e.g. "const char*" as opposed to "const char *" or "char const *" or "char const*").

      gdb/1512: no canonical way to output names of C++ types

      We currently don't have any canonical way to output names of C++ types. E.g. "const char *" versus "char const *"; more subtleties arise when dealing with templates.

      gdb/1516: [regression] local classes, gcc 2.95.3, dwarf-2

      With gcc 2.95.3 and the dwarf-2 debugging format, classes which are defined locally to a function include the demangled name of the function as part of their name. For example, if a function "foobar" contains a local class definition "Local", gdb will say that the name of the class type is "foobar__Fi.0:Local".

      This applies only to classes where the class type is defined inside a function, not to variables defined with types that are defined somewhere outside any function (which most types are).

      gdb/1588: names of c++ nested types in casts must be enclosed in quotes

      You must type

      (gdb) print ('Foo::Bar') x

      (gdb) print ('Foo::Bar' *) y
      instead of

      (gdb) print (Foo::Bar) x

      (gdb) print (Foo::Bar *) y

      gdb/1091: Constructor breakpoints ignored gdb/1193: g++ 3.3 creates multiple constructors: gdb 5.3 can't set breakpoints

      When gcc 3.x compiles a C++ constructor or C++ destructor, it generates 2 or 3 different versions of the object code. These versions have unique mangled names (they have to, in order for linking to work), but they have identical source code names, which leads to a great deal of confusion. Specifically, if you set a breakpoint in a constructor or a destructor, gdb will put a breakpoint in one of the versions, but your program may execute the other version. This makes it impossible to set breakpoints reliably in constructors or destructors.

      gcc 3.x generates these multiple object code functions in order to implement virtual base classes. gcc 2.x generated just one object code function with a hidden parameter, but gcc 3.x conforms to a multi-vendor ABI for C++ which requires multiple object code functions.

      Stack backtraces

      GDB's core code base has been updated to use a new backtrace mechanism. This mechanism makes it possible to support new features such DWARF 2 Call Frame Information (which in turn makes possible backtraces through optimized code).

      Since this code is new, it is known to still have a few problems:

      gdb/1505: [regression] gdb prints a bad backtrace for a thread

      When backtracing a thread, gdb does not stop when it reaches the outermost frame, instead continuing until it hits garbage. This is sensitive to the operating system and thread library.


      The MIPS and HPPA backtrace code has only very recently been updated to use GDB's new frame mechanism. At present there are still a few problems, in particular backtraces through signal handlers do not work.

      People encountering problems with these architectures should consult GDB's web pages and mailing lists ( to see if there are updates.


      PowerPC architecture support, in 6.1, does not use the new frame code.

      Fortunately, PowerPC architecture support, in GDB's mainline sources, have been updated. People encountering problems should consider downloading a more current snapshot of GDB (

      • "set prompt-escape-char" command deleted.

      The command "set prompt-escape-char" has been deleted. This command, and its very obscure effet on GDB's prompt, was never documented, tested, nor mentioned in the NEWS file.

      • OBSOLETE configurations and files

      Configurations that have been declared obsolete in this release have been commented out. Unless there is activity to revive these configurations, the next release of GDB will have their sources permanently REMOVED.

      Sun 3, running SunOS 3 m68*-*-sunos3*
      Sun 3, running SunOS 4 m68*-*-sunos4*
      Sun 2, running SunOS 3 m68000-*-sunos3*
      Sun 2, running SunOS 4 m68000-*-sunos4*
      Motorola 680x0 running LynxOS m68*-*-lynxos*
      AT&T 3b1/Unix pc m68*-att-*
      Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
      decstation mips-dec-* mips-little-*
      riscos mips-*-riscos* mips-*-sysv*
      sonymips mips-sony-*
      sysv mips*-*-sysv4* (IRIX 5/6 not included)
      • REMOVED configurations and files
      SGI Irix-4.x mips-sgi-irix4 or iris4
      SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
      Z8000 simulator z8k-zilog-none or z8ksim
      Matsushita MN10200 w/simulator mn10200-*-*
      H8/500 simulator h8500-hitachi-hms or h8500hms
      HP/PA running BSD hppa*-*-bsd*
      HP/PA running OSF/1 hppa*-*-osf*
      HP/PA Pro target hppa*-*-pro*
      PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
      386BSD i[3456]86-*-bsd*
      Sequent family i[3456]86-sequent-sysv4*
      SPARC running LynxOS sparc-*-lynxos*
      SPARC running SunOS 4 sparc-*-sunos4*
      Tsqware Sparclet sparclet-*-*
      Fujitsu SPARClite sparclite-fujitsu-none or sparclite