man bls-standalone (1): build log scanner, standalone version

SYNOPSIS

bls-standalone --help

bls-standalone [ global options ] check [ --compiledrulesfile rulesfile ] [ --blhc blhc-program ] logfiles

bls-standalone [ global options ] compile [ compile-options ]

bls-standalone [ global options ] checkout

DESCRIPTION

bls-standalone is the command line utility to run the build log scanner on manually specified logfiles, including support to manage the needed compiled rules definitions.

GLOBAL OPTIONS

Global options can be given before the command, available options are:

Options can be specified before the command. Each affects a different subset of commands and is ignored by other commands.

-v --verbose: increase verbosity
--libdir directory: specify the directory where the scan and compile binaries are looked for
--sharedir directory: specify the directory where the copy of the rules files and the packaged precompiled rule data resides.

COMMANDS

bls-standalone has three commands: check, compile and checkout.

check [ --compiledrulesfile rulesfile ] [ --blhc blhc-program ] logfiles

This command runs the bls scanner and the blhc scanner on the given build log files. If no compiled rules file is given with --compiledrulesfile then a previously compiled one is looked for and if there is none than the one shipped together with the package is used. blhc is also called if it is found or specified with the --blhcp option. To silence a warning about it not being found set it to NO.

compile [ -o output-file ] [ --no-defaults] [ --ignorecheckout] additional rule descriptions

Compiles the checks into a compiled form.

Unless -o is given to determine a different place, it is stored in a cache directory (determined by some environment variables) where the future check invocations will use it intsead of the packaged precompiled rules.

Additional rule descriptions can be given as command line arguments.

Rules stored in proper places of your home directory are looked at, too. (To see where they are looked for, use --verbose.)

Unless --no-defaults is given the contents of a previous checkout or the copy of the rules shipped with the package are used, too.

If there are rules of the same name, those given as command line arguments override local and original ones and local ones override original ones.

checkout

Check out the current rules used for the non-standalone build scanner into a directory where the next compile run will use them instead of the shipped rules.

Currently this checks out parts of the QA svn repository. This URL might get outdated in the future. If the bls-standalone version you use and the non-standlone bls version get out of sync, those rules might contain things that your bls-stanalone cannot handle.

WRITING RULES

Some far too short guide to writing new description files:

The non-standalone build log scanner is only run for builds deemed successful. So checks for things that should usually make a build fail makes often not much sense (a test-suite generating false positives is often more likely than catching an error ignored inproperly).

The filename is the tag produced for the test. Finding a good name is often the hardest part about writing new checks.

Most of the description file is actually the html code describing what the finding usually means to be displayed on with the exception of the lines starting with ## at the top of the file.

The description should contain the following information:

What did the check found?

Make it easy for people to find what was matched. Makes it easier to find the issue, less likely to disregard it as false-positive if it is not, and less time wasting if it actually is a false positive.

Why is what is found a problem?

Even the most serious flaws can easily be disregarded as minor issues due to ignorance. And some things are only dangerous in some sitations and don't require the highest priority in other situations. Distingushing both cases is hard and some more words in the description about it can help a lot.

What can be done against it?

Some hints how to avoid the problem both help the one due to fix it some time looking for a solution. This is especially useful to help people fixing it properly instead of only hiding the problem more thoroughly.

The actual ## directives at the start of the file are:

Merge:

This line tells that this check triggers if other checks appear at the same line.

There are currently only two forms supported:

##Merge: same tagname1 tagname2

and

##Merge: same tagname1 tagname2a or tagname2b

Match:

This is a regular expression describing what to match each line of the build log against to find the issue, prefixed with regexp:. As an extension to the regular syntax there is a atom \/ which specifies that once a line matches up to this part, no check that does not have a \/ at this place is supposed to match this line. (This is an optimisation to heavily trim down the compile state machine, but it also can be used to avoid false-positives).

As all regular expressions of all checks are compiled into a single finite state machine, checks that are very specific at the start of the line are quite cheap while checks not specific at the start are often quite expensive. The size of the state machine output by the compile command is a good measurement how expensive the specific check is.

Since:

If there are new rules then the information at might be outdated until all logs are rescanned with the new version. For each log scanned by the non-standalone build log scanner the version number of the used rules is remembered. The number specified with the Since field tells the web report generated where to place warnings that information about this check might be outdated.

Extract:

This tells how to extract information from the matched file to be showed together with the matched line (like a filename something was found in).

There are currently following forms supported here:

##Extract: simple 0 endcount 'endchar'
##Extract: simple 0 'reset' endcount 'endchar'
##Extract: simple startcount 'startchar' endcount 'endchar'
##Extract: simple startcount 'startchar' 'reset' endcount 'endchar'

Where startchar is a character to look for for the start of the extracted area (after the startcountth occurrence). resetchar is a character to abort extraction. endchar is a character to look for for the end of the extracted area (after the endcountth occurrence).

For example:
##Extract: simple 2 '|' '/' 1 '|' means to extract the content between the 2nd and 3rd pipe symbol, unless there is a slash in between.

Action:

describes what to do if a switch is matched. This can be used to set variables referenced in other rules to generate context-sensitive rules.

Condition:

add conditions (on variables set by ##Action). If the condition is not met, the generating of a finding is supressed.

CEVEATS

While compiling all matches into a single finite state machine produces very fast results, it is only feasible while the state machine does not grow too much. So care has to be taken to not use too expensive searches.

Some checks (especially context specific ones) are quite unreliable. The non-standalone build log checks do not include some findings for the summary unless they appear on multiple architectures, which bls-standalone obviously cannot do.

bls is optimized to be fast. Do not run it with rules files you do not trust. (Only the content of log files scanned is supposed to be untrusted data).

blhc is quite slow which is luckily not that noticeable if not scanning the logfiles of the whole archive. If you test new rules on a larger set of logfiles, using --blhc=NO can speed things up quite a bit.

blhc does not report line numbers so bls-standalone cannot report them for those findings.

Note that checking the logs of a dpkg-buildpackage -b run and a dpkg-buildpackage -B run can make a difference (so if you cannot reproduce a E-binary-arch-produces-all make sure you check the correct type of log).

REPORTING BUGS

Report bugs or wishlist requests to the Debian BTS
(e.g. by using reportbug bls-standalone under Debian)
or directly to