|
6.2.1 Guidelines for Test Programs
The most important rule to follow when writing testing samples is:
Look for realism.
This motto means that testing samples must be written with the same
strictness as real programs are written. In particular, you should
avoid “shortcuts” and simplifications.
Don't just play with the preprocessor if you want to prepare a
compilation. For instance, using cpp to check whether a header is
functional might let your configure accept a header which
causes some compiler error. Do not hesitate to check a header with
other headers included before, especially required headers.
Make sure the symbols you use are properly defined, i.e., refrain for
simply declaring a function yourself instead of including the proper
header.
Test programs should not write to standard output. They
should exit with status 0 if the test succeeds, and with status 1
otherwise, so that success
can be distinguished easily from a core dump or other failure;
segmentation violations and other failures produce a nonzero exit
status. Unless you arrange for exit to be declared, test
programs should return, not exit, from main,
because on many systems exit is not declared by default.
Test programs can use #if or #ifdef to check the values of
preprocessor macros defined by tests that have already run. For
example, if you call AC_HEADER_STDBOOL, then later on in
configure.ac you can have a test program that includes
stdbool.h conditionally:
#if HAVE_STDBOOL_H
# include <stdbool.h>
#endif
If a test program needs to use or create a data file, give it a name
that starts with conftest, such as conftest.data. The
configure script cleans up by running ‘rm -f -r conftest*’
after running test programs and if the script is interrupted.
|
