Testing ctags

Tmain: a facility for testing main part


Masatake YAMATO <yamato@redhat.com>

Tmain is introduced to test the area where Units does not cover well.

Units works fine for testing parsers. However, it assumes something input is given to ctags command, and a tags file is generated from ctags command.

Other aspects cannot be tested. Such areas are files and directories layout after installation, standard error output, exit status, etc.

You can run test cases with following command line:

$ make tmain

Tmain is still under development so I will not write the details here.

To write a test case, see files under Tmain/tmain-example.d. In the example, Tmain does:

  1. runs new subshell and change the working directory to Tmain/tmain-example.d,

  2. runs run.sh with bash,

  3. captures stdout, stderr and exit status, and

  4. compares them with stdout-expected.txt, stderr-expected.txt, and exit-expected.txt.

  5. compares it with tags-expected.txt if run.sh generates tags file.

run.sh is run with following 3 arguments:

  1. the path for the target ctags

  2. the path for builddir directory

  3. the path for the target readtags

The path for readtags is not reliable; readtags command is not available if --disable-readcmd was given in configure time. A case, testing the behavior of readtags, must verify the command existence with test -x $3 before going into the main part of the test.

When comparing tags file with tags-expected.txt, you must specify the path of tags explicitly with -o option in ctags command line like:

${CTAGS} ... -o $BUILDDIR/tags ...

This makes it possible to keep the original source directory clean.

See also tmain_run and tmain_compare functions in misc/units.

If run.sh exits with code 77, the test case is skipped. The output to stdout is captured and printed as the reason of skipping.


  • Run under valgrind

Tinst: installation test


Masatake YAMATO <yamato@redhat.com>

tinst target is for testing the result of make install.

$ make tinst

Fussy syntax checking

If -Wall of gcc is not enough, you may be interested in this.

You can change C compiler warning options with ‘WARNING_CFLAGS’ configure arg-var option.

$ ./configure WARNING_CFLAGS='-Wall -Wextra'

If configure option ‘--with-sparse-cgcc’ is specified, cgcc is used as CC. cgcc is part of Sparse, Semantic Parser for C. It is used in development of Linux kernel for finding programming error. cgcc acts as a c compiler but more fussy. ‘-Wsparse-all’ is used as default option passed to cgcc but you can change with ‘CGCC_CFLAGS’ configure arg-var option.

$ ./configure --with-sparse-cgcc [CGCC_CFLAGS='-Wsparse-all']

Finding performance bottleneck

See Profiling with gperftools and #383.

See also codebase.

Checking coverage

Before starting coverage measuring, you need to specify ‘--enable-coverage-gcov’ configure option.

$ ./configure --enable-coverage-gcov

After doing make clean, you can build coverage measuring ready ctags by make. At this time *.gcno files are generated by the compiler. *.gcno files can be removed with make clean.

After building ctags, you can run run-gcov target. When running *.gcda files. The target runs ctags with all input files under Units/**/input.*; and call gcov. Human readable result is printed. The detail can be shown in *.gcov files. *.gcda files and *.gcov files can be removed with make clean-gcov.

Running cppcheck

cppcheck is a tool for static C/C++ code analysis.

To run it do as following after install cppcheck:

$ make cppcheck