GNU Go Documentation
4.6.3 Assertions
Related to tracing are assertions. Developers are strongly encouraged
to pepper their code with assertions to ensure that data structures
are as they expect. For example, the helper functions make assertions
about the contents of the board in the vicinity of the move they
are evaluating.
ASSERT() is a wrapper around the standard C assert()
function. In addition to the test, it takes an extra pair of parameters
which are the co-ordinates of a "relevant" board position. If an
assertion fails, the board position is included in the trace output, and
showboard() and popgo() are called to unwind and display
the stack.
