Reporting Messages

When macros statically diagnose abnormal situations, benign or fatal, they should report them using these macros. For dynamic issues, i.e., when configure is run, see the section called “Printing Messages”.

function>AC_DIAGNOSE/function> (category, message) Report message as a warning (or as an error if requested by the user) if it falls into the category. You are encouraged to use standard categories, which currently include:

all

messages that don't fall into one of the following category. Use of an empty category is equivalent.

cross

related to cross compilation issues.

obsolete

use of an obsolete construct.

syntax

dubious syntactic constructs, incorrectly ordered macro calls.

function>AC_WARNING/function> (message) Equivalent to AC_DIAGNOSE([syntax], message), but you are strongly encouraged to use a finer grained category.

function>AC_FATAL/function> (message) Report a severe error message, and have autoconf die.

When the user runs autoconf -W error, warnings from AC_DIAGNOSE and AC_WARNING are reported as error, see the section called “Using autoconf to Create configure”.