Unexpected input can lead ctags to enter an infinite loop. The fuzz target tries to identify these conditions by passing semi-random (semi-broken) input to ctags.

$ make fuzz LANGUAGES=LANG1[,LANG2,...]

With this command line, ctags is run for random variations of all test inputs under Units/*/input.* of languages defined by LANGUAGES macro variable. In this target, the output of ctags is ignored and only the exit status is analyzed. The ctags binary is also run under timeout command, such that if an infinite loop is found it will exit with a non-zero status. The timeout will be reported as following:

[timeout C]                Units/test.vhd.t/input.vhd

This means that if C parser doesn't stop within N seconds when Units/test.vhd.t/input.vhd is given as an input, timeout will interrupt ctags. The default duration can be changed using TIMEOUT=N argument in make command. If there is no timeout but the exit status is non-zero, the target reports it as following:

[unexpected-status(N) C]                Units/test.vhd.t/input.vhd

The list of parsers which can be used as a value for LANGUAGES can be obtained with following command line

$ ./ctags --list-languages

Besides LANGUAGES and TIMEOUT, fuzz target also takes the following parameters:

VG=1

Run ctags under valgrind. If valgrind finds a memory error it is reported as:

[valgrind-error Verilog]                Units/array_spec.f90.t/input.f90

The valgrind report is recorded at Units/\*/VALGRIND-${language}.tmp.

As the same as units target, this semi-fuzz test target also calls misc/units shrink when a test case is failed. See "Units test facility" about the shrunk result.