z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

Making Libraries
A library is a file containing a collection of object files. To make a library, you specify
it as a target with the .LIBRARY attribute and list its prerequisites. The prerequisites
should be the object members that are to go into the library.
Conditionals
make tries to handle the old library construct format in a sensible way. When it
finds lib(member), it declares the lib portion as a target with the .LIBRARY attribute
and the member portion as a prerequisite of the lib target. To make the library
properly, old makefile scripts using this format must name the lib as a target and
must try to bring it up to date. The same thing happens for any target of the form
lib((entry)). These targets have an additional feature in that the entry target has the
.SYMBOL attribute set automatically.
You specify the conditional expression as follows:
.IF expression
... if text ...
.ELSE
... else text ...
.END
or:
.IF expression
... if text ...
.ELSIF expression2
... elsif text ...
.ELSE
... else text ...
.END
The .ELSE or .ELSIF portion is optional, and you can nest the conditionals (that is,
the text may contain another conditional). The .IF, .ELSE, .ELSIF, and .END
conditionals must start in the first column of the line. expression or expression2 can
have one of three forms:
string
is true if the given string is nonnull,
string == string
is true if the two strings are equal, and:
string != string
make
is true if the two strings are not equal. Typically, one or both strings contain macros,
which make expands before making comparisons. make also discards white space
at the start and end of the text portion before the comparison. This means that a
macro that expands to nothing but white space is considered a null value for the
purpose of the comparison. If a macro expression needs to be compared with a null
string, compare it to the value of the macro $(NULL).
The text enclosed in the conditional construct must have the same format that it
would have outside the conditional. In particular, make assumes that anything that
starts with a tab inside the conditional is a recipe line. This means that you cannot
use tabs to indent text inside the conditional (except, of course, for recipe lines,
which always begin with tabs).
Chapter 2. Shell command descriptions 409