In my configure.ac file I have warnings and errors like this one:
AC_MSG_ERROR([Could not find the Boost Math header files, did you specify the --with-boost-include-path option correctly?])
I'm old-fashioned and like to keep the line width less than 80 characters. However, when I split the line like this (I like some proper indentation as well)
AC_MSG_ERROR([Could not find the Boost Math header files, did you
specify the --with-boost-include-path option correctly?])
the error message keeps the line break and indentation when printed on the screen by ./configure.
What is the proper way to break a string in Autoconf?
For doing something like this it might be helpful to define M4 macros:
m4_define([bst_e1], [Could not find the Boost Math header files[,] did you])
m4_define([bst_e2], [specify the --with-boost-include-path option correctly?])
AC_MSG_ERROR(bst_e1 bst_e2)
You could also do this when the configure script is run, since AC_MSG_ERROR will take a variable:
variable=$(cat | tr '\012' ' ' <<ΕΟF
Could not find the Boost Math header files, did you
specify the --with-boost-include-path option correctly?
ΕΟF
)
AC_MSG_ERROR($variable)