[ << ] | [ < ] | [ Up ] | [ > ] | [ >> ] | [Top] | [Contents] | [Index] | [ ? ] |
7.3 Conditionals that Test Flags
You can write a conditional that tests make
command flags such as
‘-t’ by using the variable MAKEFLAGS
together with the
findstring
function
(see section Functions for String Substitution and Analysis).
This is useful when touch
is not enough to make a file appear up
to date.
The findstring
function determines whether one string appears as a
substring of another. If you want to test for the ‘-t’ flag,
use ‘t’ as the first string and the value of MAKEFLAGS
as
the other.
For example, here is how to arrange to use ‘ranlib -t’ to finish marking an archive file up to date:
archive.a: … ifneq (,$(findstring t,$(MAKEFLAGS))) +touch archive.a +ranlib -t archive.a else ranlib archive.a endif
The ‘+’ prefix marks those recipe lines as “recursive” so that
they will be executed despite use of the ‘-t’ flag.
See section Recursive Use of make
.
This document was generated on October 10, 2013 using texi2html 5.0.