<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>6. README_DEVELOPERS</title> <link rel="stylesheet" type="text/css" href="vg_basic.css"> <meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="index.html" title="Valgrind Documentation"> <link rel="up" href="dist.html" title="Valgrind Distribution Documents"> <link rel="prev" href="dist.readme-missing.html" title="5. README_MISSING_SYSCALL_OR_IOCTL"> <link rel="next" href="dist.readme-packagers.html" title="7. 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README_DEVELOPERS</h1></div></div></div> <div class="literallayout"><p><br> <br> Building and not installing it<br> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br> To run Valgrind without having to install it, run coregrind/valgrind<br> with the VALGRIND_LIB environment variable set, where <dir> is the root<br> of the source tree (and must be an absolute path). Eg:<br> <br> VALGRIND_LIB=~/grind/head4/.in_place ~/grind/head4/coregrind/valgrind <br> <br> This allows you to compile and run with "make" instead of "make install",<br> saving you time.<br> <br> Or, you can use the 'vg-in-place' script which does that for you.<br> <br> I recommend compiling with "make --quiet" to further reduce the amount of<br> output spewed out during compilation, letting you actually see any errors,<br> warnings, etc.<br> <br> <br> Building a distribution tarball<br> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br> To build a distribution tarball from the valgrind sources:<br> <br> make dist<br> <br> In addition to compiling, linking and packaging everything up, the command<br> will also attempt to build the documentation.<br> <br> If you only want to test whether the generated tarball is complete and runs<br> regression tests successfully, building documentation is not needed.<br> <br> make dist BUILD_ALL_DOCS=no<br> <br> If you insist on building documentation some embarrassing instructions<br> can be found in docs/README.<br> <br> <br> Running the regression tests<br> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br> To build and run all the regression tests, run "make [--quiet] regtest".<br> <br> To run a subset of the regression tests, execute:<br> <br> perl tests/vg_regtest <name><br> <br> where <name> is a directory (all tests within will be run) or a single<br> .vgtest test file, or the name of a program which has a like-named .vgtest<br> file. Eg:<br> <br> perl tests/vg_regtest memcheck<br> perl tests/vg_regtest memcheck/tests/badfree.vgtest<br> perl tests/vg_regtest memcheck/tests/badfree<br> <br> <br> Running the performance tests<br> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br> To build and run all the performance tests, run "make [--quiet] perf".<br> <br> To run a subset of the performance suite, execute:<br> <br> perl perf/vg_perf <name><br> <br> where <name> is a directory (all tests within will be run) or a single<br> .vgperf test file, or the name of a program which has a like-named .vgperf<br> file. Eg:<br> <br> perl perf/vg_perf perf/<br> perl perf/vg_perf perf/bz2.vgperf<br> perl perf/vg_perf perf/bz2<br> <br> To compare multiple versions of Valgrind, use the --vg= option multiple<br> times. For example, if you have two Valgrinds next to each other, one in<br> trunk1/ and one in trunk2/, from within either trunk1/ or trunk2/ do this to<br> compare them on all the performance tests:<br> <br> perl perf/vg_perf --vg=../trunk1 --vg=../trunk2 perf/<br> <br> <br> Debugging Valgrind with GDB<br> ~~~~~~~~~~~~~~~~~~~~~~~~~~~<br> To debug the valgrind launcher program (<prefix>/bin/valgrind) just<br> run it under gdb in the normal way.<br> <br> Debugging the main body of the valgrind code (and/or the code for<br> a particular tool) requires a bit more trickery but can be achieved<br> without too much problem by following these steps:<br> <br> (1) Set VALGRIND_LAUNCHER to point to the valgrind executable. Eg:<br> <br> export VALGRIND_LAUNCHER=/usr/local/bin/valgrind<br> <br> or for an uninstalled version in a source directory $DIR:<br> <br> export VALGRIND_LAUNCHER=$DIR/coregrind/valgrind<br> <br> (2) Run gdb on the tool executable. Eg:<br> <br> gdb /usr/local/lib/valgrind/ppc32-linux/lackey<br> <br> or<br> <br> gdb $DIR/.in_place/x86-linux/memcheck<br> <br> (3) Do "handle SIGSEGV SIGILL nostop noprint" in GDB to prevent GDB from<br> stopping on a SIGSEGV or SIGILL:<br> <br> (gdb) handle SIGILL SIGSEGV nostop noprint<br> <br> (4) Set any breakpoints you want and proceed as normal for gdb. The<br> macro VG_(FUNC) is expanded to vgPlain_FUNC, so If you want to set<br> a breakpoint VG_(do_exec), you could do like this in GDB:<br> <br> (gdb) b vgPlain_do_exec<br> <br> (5) Run the tool with required options (the --tool option is required<br> for correct setup), e.g.<br> <br> (gdb) run --tool=lackey pwd<br> <br> Steps (1)--(3) can be put in a .gdbinit file, but any directory names must<br> be fully expanded (ie. not an environment variable).<br> <br> A different and possibly easier way is as follows:<br> <br> (1) Run Valgrind as normal, but add the flag --wait-for-gdb=yes. This<br> puts the tool executable into a wait loop soon after it gains<br> control. This delays startup for a few seconds.<br> <br> (2) In a different shell, do "gdb /proc/<pid>/exe <pid>", where<br> <pid> you read from the output printed by (1). This attaches<br> GDB to the tool executable, which should be in the abovementioned<br> wait loop.<br> <br> (3) Do "cont" to continue. After the loop finishes spinning, startup<br> will continue as normal. Note that comment (3) above re passing<br> signals applies here too.<br> <br> <br> Self-hosting<br> ~~~~~~~~~~~~<br> This section explains :<br> (A) How to configure Valgrind to run under Valgrind.<br> Such a setup is called self hosting, or outer/inner setup.<br> (B) How to run Valgrind regression tests in a 'self-hosting' mode,<br> e.g. to verify Valgrind has no bugs such as memory leaks.<br> (C) How to run Valgrind performance tests in a 'self-hosting' mode,<br> to analyse and optimise the performance of Valgrind and its tools.<br> <br> (A) How to configure Valgrind to run under Valgrind:<br> <br> (1) Check out 2 trees, "Inner" and "Outer". Inner runs the app<br> directly. Outer runs Inner.<br> <br> (2) Configure inner with --enable-inner and build/install as usual.<br> <br> (3) Configure Outer normally and build/install as usual.<br> <br> (4) Choose a very simple program (date) and try<br> <br> outer/.../bin/valgrind --sim-hints=enable-outer --trace-children=yes \<br> --smc-check=all-non-file \<br> --run-libc-freeres=no --tool=cachegrind -v \<br> inner/.../bin/valgrind --vgdb-prefix=./inner --tool=none -v prog<br> <br> Note: You must use a "make install"-ed valgrind.<br> Do *not* use vg-in-place for the outer valgrind.<br> <br> If you omit the --trace-children=yes, you'll only monitor Inner's launcher<br> program, not its stage2. Outer needs --run-libc-freeres=no, as otherwise<br> it will try to find and run __libc_freeres in the inner, while libc is not<br> used by the inner. Inner needs --vgdb-prefix=./inner to avoid inner<br> gdbserver colliding with outer gdbserver.<br> Currently, inner does *not* use the client request <br> VALGRIND_DISCARD_TRANSLATIONS for the JITted code or the code patched for<br> translation chaining. So the outer needs --smc-check=all-non-file to<br> detect the modified code.<br> <br> Debugging the whole thing might imply to use up to 3 GDB:<br> * a GDB attached to the Outer valgrind, allowing<br> to examine the state of Outer.<br> * a GDB using Outer gdbserver, allowing to<br> examine the state of Inner.<br> * a GDB using Inner gdbserver, allowing to<br> examine the state of prog.<br> <br> The whole thing is fragile, confusing and slow, but it does work well enough<br> for you to get some useful performance data. Inner has most of<br> its output (ie. those lines beginning with "==<pid>==") prefixed with a '>',<br> which helps a lot. However, when running regression tests in an Outer/Inner<br> setup, this prefix causes the reg test diff to fail. Give <br> --sim-hints=no-inner-prefix to the Inner to disable the production<br> of the prefix in the stdout/stderr output of Inner.<br> <br> The allocator (coregrind/m_mallocfree.c) is annotated with client requests<br> so Memcheck can be used to find leaks and use after free in an Inner<br> Valgrind.<br> <br> The Valgrind "big lock" is annotated with helgrind client requests<br> so helgrind and drd can be used to find race conditions in an Inner<br> Valgrind.<br> <br> All this has not been tested much, so don't be surprised if you hit problems.<br> <br> When using self-hosting with an outer Callgrind tool, use '--pop-on-jump'<br> (on the outer). Otherwise, Callgrind has much higher memory requirements. <br> <br> (B) Regression tests in an outer/inner setup:<br> <br> To run all the regression tests with an outer memcheck, do :<br> perl tests/vg_regtest --outer-valgrind=../outer/.../bin/valgrind \<br> --all<br> <br> To run a specific regression tests with an outer memcheck, do:<br> perl tests/vg_regtest --outer-valgrind=../outer/.../bin/valgrind \<br> none/tests/args.vgtest<br> <br> To run regression tests with another outer tool:<br> perl tests/vg_regtest --outer-valgrind=../outer/.../bin/valgrind \<br> --outer-tool=helgrind --all<br> <br> --outer-args allows to give specific arguments to the outer tool,<br> replacing the default one provided by vg_regtest.<br> <br> Note: --outer-valgrind must be a "make install"-ed valgrind.<br> Do *not* use vg-in-place.<br> <br> When an outer valgrind runs an inner valgrind, a regression test<br> produces one additional file <testname>.outer.log which contains the<br> errors detected by the outer valgrind. E.g. for an outer memcheck, it<br> contains the leaks found in the inner, for an outer helgrind or drd,<br> it contains the detected race conditions.<br> <br> The file tests/outer_inner.supp contains suppressions for <br> the irrelevant or benign errors found in the inner.<br> <br> (C) Performance tests in an outer/inner setup:<br> <br> To run all the performance tests with an outer cachegrind, do :<br> perl perf/vg_perf --outer-valgrind=../outer/.../bin/valgrind perf<br> <br> To run a specific perf test (e.g. bz2) in this setup, do :<br> perl perf/vg_perf --outer-valgrind=../outer/.../bin/valgrind perf/bz2<br> <br> To run all the performance tests with an outer callgrind, do :<br> perl perf/vg_perf --outer-valgrind=../outer/.../bin/valgrind \<br> --outer-tool=callgrind perf<br> <br> Note: --outer-valgrind must be a "make install"-ed valgrind.<br> Do *not* use vg-in-place.<br> <br> To compare the performance of multiple Valgrind versions, do :<br> perl perf/vg_perf --outer-valgrind=../outer/.../bin/valgrind \<br> --outer-tool=callgrind \<br> --vg=../inner_xxxx --vg=../inner_yyyy perf<br> (where inner_xxxx and inner_yyyy are the toplevel directories of<br> the versions to compare).<br> Cachegrind and cg_diff are particularly handy to obtain a delta<br> between the two versions.<br> <br> When the outer tool is callgrind or cachegrind, the following<br> output files will be created for each test:<br> <outertoolname>.out.<inner_valgrind_dir>.<tt>.<perftestname>.<pid><br> <outertoolname>.outer.log.<inner_valgrind_dir>.<tt>.<perftestname>.<pid><br> (where tt is the two letters abbreviation for the inner tool(s) run).<br> <br> For example, the command<br> perl perf/vg_perf \<br> --outer-valgrind=../outer_trunk/install/bin/valgrind \<br> --outer-tool=callgrind \<br> --vg=../inner_tchain --vg=../inner_trunk perf/many-loss-records<br> <br> produces the files<br> callgrind.out.inner_tchain.no.many-loss-records.18465<br> callgrind.outer.log.inner_tchain.no.many-loss-records.18465<br> callgrind.out.inner_tchain.me.many-loss-records.21899<br> callgrind.outer.log.inner_tchain.me.many-loss-records.21899<br> callgrind.out.inner_trunk.no.many-loss-records.21224<br> callgrind.outer.log.inner_trunk.no.many-loss-records.21224<br> callgrind.out.inner_trunk.me.many-loss-records.22916<br> callgrind.outer.log.inner_trunk.me.many-loss-records.22916<br> <br> <br> Printing out problematic blocks<br> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br> If you want to print out a disassembly of a particular block that<br> causes a crash, do the following.<br> <br> Try running with "--vex-guest-chase-thresh=0 --trace-flags=10000000<br> --trace-notbelow=999999". This should print one line for each block<br> translated, and that includes the address.<br> <br> Then re-run with 999999 changed to the highest bb number shown.<br> This will print the one line per block, and also will print a<br> disassembly of the block in which the fault occurred.<br> <br> </p></div> </div> <div> <br><table class="nav" width="100%" cellspacing="3" cellpadding="2" border="0" summary="Navigation footer"> <tr> <td rowspan="2" width="40%" align="left"> <a accesskey="p" href="dist.readme-missing.html"><< 5. README_MISSING_SYSCALL_OR_IOCTL</a> </td> <td width="20%" align="center"><a accesskey="u" href="dist.html">Up</a></td> <td rowspan="2" width="40%" align="right"> <a accesskey="n" href="dist.readme-packagers.html">7. README_PACKAGERS >></a> </td> </tr> <tr><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td></tr> </table> </div> </body> </html>