When macros statically diagnose abnormal situations, benign or fatal,
they should report them using these macros. For issuing dynamic issues,
configure is run, see Printing Messages.
Assert that the arithmetic expression evaluates to non-zero.
Otherwise, issue a fatal error, and exit
Similar to the builtin
m4_errprint, except that a newline is
guaranteed after message.
Report a severe error message prefixed with the current location,
Useful as a prefix in a message line. Short for:
Report message as a warning (or as an error if requested by the
user) if warnings of the category are turned on. If the message
is emitted, it is prefixed with the current location, and followed by a
call trace of all macros defined via
AC_DEFUN used to get to the
current expansion. You are encouraged to use standard categories, which
messages that don’t fall into one of the following categories. Use of an empty category is equivalent.
related to cross compilation issues.
use of an obsolete construct.
dubious syntactic constructs, incorrectly ordered macro calls.