When macros statically diagnose abnormal situations, benign or fatal, they should report them using these macros. For issuing dynamic issues, i.e., when configure is run, see Printing Messages.
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_DEFUNused to get to the current expansion. You are encouraged to use standard categories, which currently include:
- 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.