usage: valgrind [options] prog-and-args

  tool-selection option, with default in [ ]:
    --tool=<name>             use the Valgrind tool named <name> [memcheck]

  basic user options for all Valgrind tools, with defaults in [ ]:
    -h --help                 show this message
    --help-debug              show this message, plus debugging options
    --version                 show version
    -q --quiet                run silently; only print error msgs
    -v --verbose              be more verbose -- show misc extra info
    --trace-children=no|yes   Valgrind-ise child processes (follow execve)? [no]
    --trace-children-skip=patt1,patt2,...    specifies a list of executables
                              that --trace-children=yes should not trace into
    --trace-children-skip-by-arg=patt1,patt2,...   same as --trace-children-skip=
                              but check the argv[] entries for children, rather
                              than the exe name, to make a follow/no-follow decision
    --child-silent-after-fork=no|yes omit child output between fork & exec? [no]
    --vgdb=no|yes|full        activate gdbserver? [yes]
                              full is slower but provides precise watchpoint/step
    --vgdb-error=<number>     invoke gdbserver after <number> errors [999999999]
                              to get started quickly, use --vgdb-error=0
                              and follow the on-screen directions
    --vgdb-stop-at=event1,event2,... invoke gdbserver for given events [none]
         where event is one of:
           startup exit valgrindabexit all none
    --track-fds=no|yes        track open file descriptors? [no]
    --time-stamp=no|yes       add timestamps to log messages? [no]
    --log-fd=<number>         log messages to file descriptor [2=stderr]
    --log-file=<file>         log messages to <file>
    --log-socket=ipaddr:port  log messages to socket ipaddr:port

  user options for Valgrind tools that report errors:
    --xml=yes                 emit error output in XML (some tools only)
    --xml-fd=<number>         XML output to file descriptor
    --xml-file=<file>         XML output to <file>
    --xml-socket=ipaddr:port  XML output to socket ipaddr:port
    --xml-user-comment=STR    copy STR verbatim into XML output
    --demangle=no|yes         automatically demangle C++ names? [yes]
    --num-callers=<number>    show <number> callers in stack traces [12]
    --error-limit=no|yes      stop showing new errors if too many? [yes]
    --error-exitcode=<number> exit code to return if errors found [0=disable]
    --error-markers=<begin>,<end> add lines with begin/end markers before/after
                              each error output in plain text mode [none]
    --show-below-main=no|yes  continue stack traces below main() [no]
    --default-suppressions=yes|no
                              load default suppressions [yes]
    --suppressions=<filename> suppress errors described in <filename>
    --gen-suppressions=no|yes|all    print suppressions for errors? [no]
    --input-fd=<number>       file descriptor for input [0=stdin]
    --dsymutil=no|yes         run dsymutil on Mac OS X when helpful? [yes]
    --max-stackframe=<number> assume stack switch for SP changes larger
                              than <number> bytes [2000000]
    --main-stacksize=<number> set size of main thread's stack (in bytes)
                              [min(max(current 'ulimit' value,1MB),16MB)]

  user options for Valgrind tools that replace malloc:
    --alignment=<number>      set minimum alignment of heap allocations [not used by this tool]
    --redzone-size=<number>   set minimum size of redzones added before/after
                              heap blocks (in bytes). [not used by this tool]

  uncommon user options for all Valgrind tools:
    --fullpath-after=         (with nothing after the '=')
                              show full source paths in call stacks
    --fullpath-after=string   like --fullpath-after=, but only show the
                              part of the path after 'string'.  Allows removal
                              of path prefixes.  Use this flag multiple times
                              to specify a set of prefixes to remove.
    --extra-debuginfo-path=path    absolute path to search for additional
                              debug symbols, in addition to existing default
                              well known search paths.
    --debuginfo-server=ipaddr:port    also query this server
                              (valgrind-di-server) for debug symbols
    --allow-mismatched-debuginfo=no|yes  [no]
                              for the above two flags only, accept debuginfo
                              objects that don't "match" the main object
    --smc-check=none|stack|all|all-non-file [all-non-file]
                              checks for self-modifying code: none, only for
                              code found in stacks, for all code, or for all
                              code except that from file-backed mappings
    --read-inline-info=yes|no read debug info about inlined function calls
                              and use it to do better stack traces.  [yes]
                              on Linux/Android/Solaris for Memcheck/Helgrind/DRD
                              only.  [no] for all other tools and platforms.
    --read-var-info=yes|no    read debug info on stack and global variables
                              and use it to print better error messages in
                              tools that make use of it (Memcheck, Helgrind,
                              DRD) [no]
    --vgdb-poll=<number>      gdbserver poll max every <number> basic blocks [5000] 
    --vgdb-shadow-registers=no|yes   let gdb see the shadow registers [no]
    --vgdb-prefix=<prefix>    prefix for vgdb FIFOs [.../vgdb-pipe]
    --run-libc-freeres=no|yes free up glibc memory at exit on Linux? [yes]
    --sim-hints=hint1,hint2,...  activate unusual sim behaviours [none] 
         where hint is one of:
           lax-ioctls lax-doors fuse-compatible enable-outer
           no-inner-prefix no-nptl-pthread-stackcache none
    --fair-sched=no|yes|try   schedule threads fairly on multicore systems [no]
    --kernel-variant=variant1,variant2,...
         handle non-standard kernel variants [none]
         where variant is one of:
           bproc android-no-hw-tls
           android-gpu-sgx5xx android-gpu-adreno3xx none
    --merge-recursive-frames=<number>  merge frames between identical
           program counters in max <number> frames) [0]
    --num-transtab-sectors=<number> size of translated code cache [16]
           more sectors may increase performance, but use more memory.
    --avg-transtab-entry-size=<number> avg size in bytes of a translated
           basic block [0, meaning use tool provided default]
    --aspace-minaddr=0xPP     avoid mapping memory below 0xPP [guessed]
    --valgrind-stacksize=<number> size of valgrind (host) thread's stack
                               (in bytes) [1048576]
    --show-emwarns=no|yes     show warnings about emulation limits? [no]
    --require-text-symbol=:sonamepattern:symbolpattern    abort run if the
                              stated shared object doesn't have the stated
                              text symbol.  Patterns can contain ? and *.
    --soname-synonyms=syn1=pattern1,syn2=pattern2,... synonym soname
              specify patterns for function wrapping or replacement.
              To use a non-libc malloc library that is
                  in the main exe:  --soname-synonyms=somalloc=NONE
                  in libxyzzy.so:   --soname-synonyms=somalloc=libxyzzy.so
    --sigill-diagnostics=yes|no  warn about illegal instructions? [yes]
    --unw-stack-scan-thresh=<number>   Enable stack-scan unwind if fewer
                  than <number> good frames found  [0, meaning "disabled"]
                  NOTE: stack scanning is only available on arm-linux.
    --unw-stack-scan-frames=<number>   Max number of frames that can be
                  recovered by stack scanning [5]
    --resync-filter=no|yes|verbose [yes on MacOS, no on other OSes]
              attempt to avoid expensive address-space-resync operations
    --max-threads=<number>    maximum number of threads that valgrind can
                              handle [500]

  user options for Nulgrind:
    (none)

  Extra options read from ~/.valgrindrc, $VALGRIND_OPTS, ./.valgrindrc

  Nulgrind is Copyright (C) 2002-2015, and GNU GPL'd, by Nicholas Nethercote.
  Valgrind is Copyright (C) 2000-2015, and GNU GPL'd, by Julian Seward et al.
  LibVEX is Copyright (C) 2004-2015, and GNU GPL'd, by OpenWorks LLP et al.

  Bug reports, feedback, admiration, abuse, etc, to: www.valgrind.org.