This commit implements in python a set of GDB commands corresponding to the
Valgrind gdbserver monitor commands.
Basically, the idea is that one GDB command is defined for each valgrind
gdbserver subcommand and will generate and send a monitor command to valgrind.
The python code is auto-loaded by GDB as soon as GDB observes that the valgrind
preload core shared lib is loaded (e.g. vgpreload_core-amd64-linux.so).
This automatic loading is done thanks to the .debug_gdb_scripts section
added in vg_preloaded.c file.
Sadly, the auto-load only happens once valgrind has started to execute the code
of ld that loads this vg_preload file.
I have tried 2 approaches to have the python code auto-loaded when attaching at
startup to valgrind:
* have valgrind gdbserver reporting first to GDB that the executable file is
the tool executable (with a .debug_gdb_scripts section) and then reporting
the real (guest) executable file.
The drawback of this approach is that it triggers a warning/question in GDB
according to the GDB setting 'set exec-file-mismatch'.
* have valgrind gdbserver pretending to be multiprocess enabled, and report
a fake process using the tool executable with a .debug_gdb_scripts section.
The drawback of this is that this always creates a second inferior in GDB,
which will be confusing.
Possibly, we might complete the below message :
==2984378== (action at startup) vgdb me ...
==2984378==
==2984378== TO DEBUG THIS PROCESS USING GDB: start GDB like this
==2984378== /path/to/gdb /home/philippe/valgrind/littleprogs/some_mem
==2984378== and then give GDB the following command
==2984378== target remote | /home/philippe/valgrind/git/improve/Inst/libexec/valgrind/../../bin/vgdb --pid=2984378
==2984378== --pid is optional if only one valgrind process is running
with:
==2984378== GDB valgrind python specific commands will be auto-loaded when execution begins.
==2984378== Alternatively, you might load it before with the GDB command:
==2984378== source /abs/path/to/valgrind/install/libexec/valgrind/valgrind-monitor.py
The following GDB setting traces the monitor commands sent by a GDB valgrind
command to the valgrind gdbserver:
set debug valgrind-execute-monitor on
How to use the new GDB valgrind commands?
-----------------------------------------
The usage of the GDB front end commands is compatible with the
monitor command as accepted today by Valgrind.
For example, the memcheck monitor command "xb' has the following usage:
xb <addr> [<len>]
With some piece of code:
'char some_mem [5];'
xb can be used the following way:
(gdb) print &some_mem
(gdb) $2 = (char (*)[5]) 0x1ffefffe8b
(gdb) monitor xb 0x1ffefffe8b 5
ff ff ff ff ff
0x4A43040: 0x00 0x00 0x00 0x00 0x00
(gdb)
The same action can be done with the new GDB 'memcheck xb' command:
(gdb) memcheck xb 0x1ffefffe8b 5
ff ff ff ff ff
0x1FFEFFFE8B: 0x00 0x00 0x00 0x00 0x00
(gdb)
At this point, you might ask yourself: "what is the interest ?".
Using GDB valgrind commands provides several advantages compared to
the valgrind gdbserver monitor commands.
Evaluation of arguments by GDB:
-------------------------------
For relevant arguments, the GDB command will evaluate its arguments using
the usual GDB evaluation logic, for example, instead of printing/copying
the address and size of 'some_mem', the following will work:
(gdb) memcheck xb &some_mem sizeof(some_mem)
ff ff ff ff ff
0x1FFEFFFE8B: 0x00 0x00 0x00 0x00 0x00
(gdb)
or:
(gdb) p some_mem
$4 = "\000\000\000\000"
(gdb) memcheck xb &$4
ff ff ff ff ff
0x1FFEFFFE8B: 0x00 0x00 0x00 0x00 0x00
(gdb)
This is both easier to use interactively and easier to use in GDB scripts,
as you can directly use variable names in the GDB valgrind commands.
Command completion by GDB:
--------------------------
The usual command completion in GDB will work for the GDB valgrind commands.
For example, typing TAB after the letter 'l' in:
(gdb) valgrind v.info l
will show the 2 "valgrind v.info" subcommands:
last_error location
(gdb) valgrind v.info l
Note that as usual, GDB will recognise a command as soon as it is unambiguous.
Usual help and apropos support by GDB:
--------------------------------------
The Valgrind gdbserver provides an online help using:
(gdb) monitor help
However, this gives the help for all monitor commands, and is not searchable.
GDB provides a better help and documentation search.
For example, the following commands can be used to get various help
or search the GDB Valgrind command online documentation:
help valgrind
help memcheck
help helgrind
help callgrind
help massif
to get help about the general valgrind commands or the tool specific commands.
Examples of searching the online documentation:
apropos valgrind.*location
apropos -v validity
apropos -v leak
User can define aliases for the valgrind commands:
--------------------------------------------------
The following aliases are predefined:
v and vg for valgrind
mc for memcheck
hg for helgrind
cg for callgrind
ms for massif
So, the following will be equivalent:
(gdb) valgrind v.info location &some_mem
(gdb) v v.i lo &some_mem
(gdb) alias Vl = valgrind v.info location
(gdb) Vl &some_mem
Thanks to Hassan El Karouni for the help in factorising the python
code common to all valgrind python commands using a decorator.
This makes the rule for xmllint easier since it doesn't need to
override the DTD to validate against. It also helps with other tools
tryinf to process the docbookx xml files.
- The command option --collect-systime has been enhanced to specify
the unit used to record the elapsed time spent during system calls.
The command option now accepts the values no|yes|msec|usec|nsec,
where yes is a synonym of msec. When giving the value nsec, the
system cpu time of system calls is also recorded.
Note that the nsec option is not supported on Darwin.
Because it's very useful. As part of this, the "percentage of events
annotated" numbers at the bottom of the output is changed to "events
annotated" so that --show-percs doesn't compute a percentage of a
percentage.
Example output lines:
```
4,967,137,442 (100.0%) PROGRAM TOTALS
4,543 (25.23%) 17,566 ( 0.43%) 47,993 ( 0.92%) /build/glibc-OTsEL5/glibc-2.27/elf/dl-lookup.c
1 ( 0.01%) 2,000,001 (49.29%) 3,000,004 (57.36%) for (int i = 0; i < 1000000; i++) {
```
The commit also adds some much-needed tests for cg_annotate and
callgrind_annotate.
KCachegrind currently uses a quick format detection before
actually loading a file, and checks for a line starting with
"events:" in the first 2kB for that. This obviously is fragile,
as shown by an internal bug report by Philippe: before the
"events" line, Callgrind puts a "cmd:" line with the command
line. If this is very long, the detection fails and the file
does not get loaded at all.
While KCachegrind would not need to have this quick format
check at all, it is useful if multiple input format filters
get supported at some point, to automatically select the
correct filter.
Further, for the "file" command, for file managers and
desktop environments, having an unique way to detect a
file format is important.
It is not too late to fix this issue for the callgrind format.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@16196
* callgrind_annotate: ignore the lines giving the long names of the
events: such lines are used by kcachegrind for the GUI, so are better
accepted (and ignored) by callgrind_annotate
* Document in callgrind_annotate manual that thresholds can be given
per event kind.
* Avoid a division by zero in callgrind_annotate, for 'special data'
such as produced by (some) xtrees.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@16125
If valgrind is started with --vgdb-prefix arg, then callgrind_control
cannot find and control this valgrind.
So, add an (optional) argument to callgrind_control,
and have callgrind tool report the needed vgdb prefix argument
if the user supplied this arg.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13769
Bug found by, and fix based on a patch by Mark Wielaard
Callgrind format specification was inconsistent with
what Callgrind generates, and what callgrind_annotate
accepted. Now, callgrind_annotate accepts the examples
in the format specification.
* Callgrind writes 'cfi=' lines for when a call target goes
into another source file. According to the spec, 'cfl=' is
used for this. Change the spec to allow both, and change
callgrind_annotate to accept both.
* The spec requires just an "events:" line as minimum header
to render the file as correct according to the specification.
callgrind_annotate also expected a 'cmd=' line. Fixed.
* The 'summary:' line is optional in the spec. Fixed in
callgrind_annotate. If not provided, summary is calculated
from all cost lines.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13310
The vgdb "status" monitor command is still available, but
used for pretty printing of status information now (acutally,
just some place holder for real information up to now: just
number of running threads). The internal interface used by
callgrind_control to provide stack traces and event counts
is using "status internal", and is not documented, as the
format is not for human consumption.
This also adds some documentation.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12014
--cmd-time-out
* changed prefixes of Valgrind core monitor commands from vg. to v.
* removed prefixes of Tool monitor commands
* memcheck leak_check 'leakpossible' arg renamed to 'possibleleak'
* memcheck make_memory 'ifaddressabledefined' arg renamed to
'Definedifaddressable'
(with uppercase D to avoid confusion with 'defined' arg).
* vgdb options
- Some doc updates : more logical option order documentation,
specify 'standalone' for options aimed at standalone usage.
- added option --cmd-time-out for standalone vgdb
(comment of Josef Weindendorfer, needed to interface with a callgrind GUI)
* updated tests according to the above.
* updated documentation according to the above.
* some additional minor doc fixes/clarifications
(Philippe Waroquiers, philippe.waroquiers@skynet.be). Bug 214909
comment 111.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11844
of the L2 cache. This is to accommodate machines with three levels of
cache. We still only simulate two levels, the first and the last.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11404
Callgrind now uses Cachegrind's command line option to switch
on simulation: "--branch-sim=yes/no" for branch prediction,
and "--cache-sim=yes/no" for cache simulation (for more
consistency and to avoid confusion). However, the previously
used "--simulate-cache=yes/no" still is supported but deprecated.
Included: according documentation and tests.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11207
To count global bus lock events, use "--collect-bus=yes".
For x86, this will count the number of executed instructions
with a lock prefix; for architectures with LL/SC, this will
count the number of executed SC instructions.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11167
Get rid of "-v" as short form of "--version".
Also, help text for dumps/instrumentation shows only the long
versions now. However, '-i on' or '-d dump now!' is still possible.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10754
a manpage, and they're so simple I can't be bothered doing ones for them
(they don't even have sections in the manual).
Also fixed a few minor things relating to manpages.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10744
and created man pages for them. Renamed the XML files in the process for
consistency.
- Inlined cg-entities.xml into vg-entities.xml.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10742
- Actually remove the dead docs/images/massif*.png files (this was meant to
happen in r10720).
- Inline $TOOL/docs/Makefile.am into $TOOL/Makefile.am for all 10 tools. 10
fewer Makefile.am files FTW!
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10721
line options. This commit changes them to all <option>.
Also make consistent how options with multiple names (eg. -h --help) are
shown.
Also, remove section describing --help and --version in Callgrind's chapter;
these aren't necessary and are presumably a hangover from when Callgrind was
a separate tool.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10659
- There were detailed descriptions of all the tools in the Quick Start
Guide, the Manual introduction, and the start of each tool chapter. To
avoid duplication/overlap, I removed these altogether from the Quick Start
Guide, and shortened them in the intro.
- Improved the description of what errors Memcheck can find.
- Made all tool chapters start with "Overview" section, for consistency.
- Made the "run with --tool=XXX" bit consistent in each tool chapter.
- Made all tool chapter titles match the description given when running them.
- Added BBV to the User Manual intro.
- Generally clarified, updated, and future-proofed various bits of text in
the Quick Start Guide and User Manual introduction.
Also:
- Changed Nulgrind's start-up description to "the minimal Valgrind tool".
- Fixed some punctuation in the usage message.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10652
This obviously was already wrong in 3.2.x :-(
* Old --fn-recursion=... / --fn-caller=... options are called
--separate-recs=... / --separate-callers=... since quite some
time for consistency with e.g. --separate-threads=yes.
Error noted from bug 153335.
* Function specifications support wildcards since quite some time;
specification of a prefix only does not work, but the full
function has to match. This was needed to allow to specify 'foo'
without also specifying 'foo1'.
* The script 'callgrind' does not exist since merging into
valgrind.
* Rename callgrind from being a 'heavyweight' to a 'call graph'
profiler, similar to the description in the quick start overview.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7272
