-Release 3.4.0 (???)
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Release 3.4.0 (2 January 2009)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+3.4.0 is a feature release with many significant improvements and the
+usual collection of bug fixes. This release supports X86/Linux,
+AMD64/Linux, PPC32/Linux and PPC64/Linux. Support for recent distros
+(using gcc 4.4, glibc 2.8 and 2.9) has been added.
+
+3.4.0 brings some significant tool improvements. Memcheck can now
+report the origin of uninitialised values, the thread checkers
+Helgrind and DRD are much improved, and we have a new experimental
+tool, exp-Ptrcheck, which is able to detect overruns of stack and
+global arrays. In detail:
+
+* Memcheck is now able to track the origin of uninitialised values.
+ When it reports an uninitialised value error, it will try to show
+ the origin of the value, as either a heap or stack allocation.
+ Origin tracking is expensive and so is not enabled by default. To
+ use it, specify --track-origins=yes. Memcheck's speed will be
+ essentially halved, and memory usage will be significantly
+ increased. Nevertheless it can drastically reduce the effort
+ required to identify the root cause of uninitialised value errors,
+ and so is often a programmer productivity win, despite running more
+ slowly.
+
+* A version (1.4.0) of the Valkyrie GUI, that works with Memcheck in
+ 3.4.0, will be released at the same time as 3.4.0.
+
+* Helgrind's race detection algorithm has been completely redesigned
+ and reimplemented, to address usability and scalability concerns:
+
+ - The new algorithm has a lower false-error rate: it is much less
+ likely to report races that do not really exist.
+
+ - Helgrind will display full call stacks for both accesses involved
+ in a race. This makes it far easier to identify the root causes
+ of races.
+
+ - Limitations on the size of program that can run have been removed.
+
+ - Performance has been modestly improved, although that is very
+ workload-dependent.
+
+ - Direct support for Qt4 threading has been added.
+
+ - pthread_barriers are now directly supported.
+
+ - Helgrind works well on all supported Linux targets.
-Main change points (need to add details for all)
+* The DRD thread debugging tool has seen major improvements:
-- Origin tracking in Memcheck
+ - Greatly improved performance and significantly reduced memory
+ usage.
-- Helgrind completely rewritten, to remove false error and scaling
-problems and to give improved diagnostics
+ - Support for several major threading libraries (Boost.Thread, Qt4,
+ glib, OpenMP) has been added.
-- Drd majorly improved (details ..)
+ - Support for atomic instructions, POSIX semaphores, barriers and
+ reader-writer locks has been added.
-- New tool: exp-ptrcheck, for doing checks on stack and global arrays
+ - Works now on PowerPC CPUs too.
-- gcc-4.4.0 support, including demangler fixes for recent g++'s
+ - Added support for printing thread stack usage at thread exit time.
-- new distro support: OpenSUSE 11.1, Fedora 10, Ubuntu 8.10
+ - Added support for debugging lock contention.
-- Frame level wildcarding in suppressions
+ - Added a manual for Drd.
-- Basic support for IBM Power6 (64-bit processes only)
+* A new experimental tool, exp-Ptrcheck, has been added. Ptrcheck
+ checks for misuses of pointers. In that sense it is a bit like
+ Memcheck. However, Ptrcheck can do things Memcheck can't: it can
+ detect overruns of stack and global arrays, it can detect
+ arbitrarily far out-of-bounds accesses to heap blocks, and it can
+ detect accesses heap blocks that have been freed a very long time
+ ago (millions of blocks in the past).
-- SSSE3 insns now supported. Changed CPUID output to be Core-2, so now it
- claims to be a Core 2 E6600.
+ Ptrcheck currently works only on x86-linux and amd64-linux. To use
+ it, use --tool=exp-ptrcheck. A simple manual is provided, as part
+ of the main Valgrind documentation. As this is an experimental
+ tool, we would be particularly interested in hearing about your
+ experiences with it.
+
+* exp-Omega, an experimental instantaneous leak-detecting tool,
+ has been removed from the distribution.
+
+* As usual, support for the latest Linux distros and toolchain
+ components has been added. It should work well on Fedora Core 10,
+ OpenSUSE 11.1 and Ubuntu 8.10. gcc-4.4 (in its current pre-release
+ state) is supported, as is glibc-2.9. The C++ demangler has been
+ updated so as to work well with C++ compiled by even the most recent
+ g++'s.
+
+* You can now use frame-level wildcards in suppressions. This was a
+ frequently-requested enhancement. A line "..." in a suppression now
+ matches zero or more frames. This makes it easier to write
+ suppressions which are precise yet insensitive to changes in
+ inlining behaviour.
+
+* 3.4.0 adds support on x86/amd64 for the SSSE3 instruction set.
+
+* Very basic support for IBM Power6 has been added (64-bit processes only).
+
+* Valgrind is now cross-compilable. For example, it is possible to
+ cross compile Valgrind on an x86/amd64-linux host, so that it runs
+ on a ppc32/64-linux target.
+
+* The following bugs have been fixed. Note that "n-i-bz" stands for
+ "not in bugzilla" -- that is, a bug that was reported to us but
+ never got a bugzilla entry. We encourage you to file bugs in
+ bugzilla (http://bugs.kde.org/enter_valgrind_bug.cgi) rather than
+ mailing the developers (or mailing lists) directly.
+
+ // fill this bit in
+
+Developer-visible changes:
-- cross-compilation support
+* Valgrind's debug-info reading machinery has been majorly overhauled.
+ It can now correctly establish the addresses for ELF data symbols,
+ which is something that has never worked properly before now.
-- many bugs fixed, as usual
+ Also, Valgrind can now read DWARF3 type and location information for
+ stack and global variables. This makes it possible to use the
+ framework to build tools that rely on knowing the type and locations
+ of stack and global variables, for example exp-Ptrcheck.
-- non-user-visible: able to read Dwarf3 type/variable information,
- so as to understand the location and type of stack and local variables
+ Reading of such information is disabled by default, because most
+ tools don't need it, and because it is expensive in space and time.
+ However, you can force Valgrind to read it, using the
+ --read-var-info=yes flag. Memcheck, Helgrind and DRD are able to
+ make use of such information, if present, to provide source-level
+ descriptions of data addresses in the error messages they create.
-- matching release of Valkyrie, (a GUI for Memcheck), v 1.4.0
+(3.4.0.RC1: 23 Dec 2008, vex rXXXX, valgrind rXXXX).
-- what else?
Release 3.3.1 (4 June 2008)
projects / thirdparty / valgrind.git / commitdiff
