As there were in Make, so there are certain targets that have special meaning to PMake. When you use one on a dependency line, it is the only target that may appear on the left-hand-side of the operator. As for the attributes and variables, all the special targets begin with a period and consist of upper-case letters only. I will not describe them all in detail because some of them are rather complex and I will describe them in more detail than you will want in Chapter 4, PMake for Gods. The targets are as follows:
.BEGIN | Any commands attached to this target are executed before anything else is done. You can use it for any initialization that needs doing. |
.DEFAULT | This is sort of a .USE
rule for any target (that was used only as a source)
that PMake can not figure
out any other way to create. It is only “sort
of” a .USE rule because
only the shell script attached to the
.DEFAULT target is used.
The .IMPSRC variable of a target
that inherits .DEFAULT's
commands is set to the target's own
name. |
.END | This serves a function similar to
.BEGIN, in that commands
attached to it are executed once everything
has been re-created (so long as no errors
occurred). It also serves the extra function of
being a place on which PMake
can hang commands you put off to the end. Thus the script
for this target will be executed before any of the
commands you save with the
“...”. |
.EXPORT | The sources for this target are passed to the exportation system compiled into PMake. Some systems will use these sources to configure themselves. You should ask your system administrator about this. |
.IGNORE | This target marks each of its sources
with the .IGNORE attribute.
If you do not give it any sources, then it is
like giving the -i flag when
you invoke PMake –
errors are ignored for all commands. |
.INCLUDES | The sources for this target are taken to be
suffixes that indicate a file that can be included in
a program source file. The suffix must have
already been declared with .SUFFIXES : .bitmap .PATH.bitmap : /usr/local/X/lib/bitmaps .INCLUDES : .bitmap
PMake will place
cc $(.INCLUDES) -c xprogram.c
(Note: the |
.INTERRUPT | When PMake is interrupted, it will execute the commands in the script for this target, if it exists. |
.LIBS | This does for libraries what
.INCLUDES does for include
files, except the flag used is
-L, as required by those linkers
that allow you to tell them where to find libraries.
The variable used is .LIBS.
Be forewarned that PMake
may not have been compiled to do this if the linker
on your system does not accept the -L
flag, though the .LIBS variable
will always be defined once the makefile has been
read. |
.MAIN | If you did not give a target (or targets) to create when you invoked PMake, it will take the sources of this target as the targets to create. |
.MAKEFLAGS | This target provides a way for you to
always specify flags for PMake
when the makefile is used. The flags are just as they
would be typed to the shell (except you can not use shell
variables unless they are in the environment), though
the -f and -r
flags have no effect. |
.NULL | This allows you to specify what suffix PMake should pretend a file has if, in fact, it has no known suffix. Only one suffix may be so designated. The last source on the dependency line is the suffix that is used (you should, however, only give one suffix...). |
.PATH | If you give sources for this target, PMake will take them as directories in which to search for files it cannot find in the current directory. If you give no sources, it will clear out any directories added to the search path before. Since the effects of this all get very complex, we will leave it till Chapter 4, PMake for Gods to give you a complete explanation. |
.PATH | This does a similar thing to
.PATH, but it does it only
for files with the given suffix. The suffix must
have been defined already. Look at Search Paths
(Section 4.1, “Search Paths”) for more
information. |
.PRECIOUS | Similar to .IGNORE,
this gives the .PRECIOUS attribute to
each source on the dependency line, unless there are
no sources, in which case the .PRECIOUS
attribute is given to every target in the file. |
.RECURSIVE | This target applies the .MAKE
attribute to all its sources. It does nothing if you
do not give it any sources. |
.SHELL | PMake is not constrained to only using the Bourne shell to execute the commands you put in the makefile. You can tell it some other shell to use with this target. Check out “A Shell is a Shell is a Shell” (Section 4.4, “A Shell is a Shell is a Shell”) for more information. |
.SILENT | When you use
.SILENT as a target, it
applies the .SILENT attribute to
each of its sources. If there are no sources on the
dependency line, then it is as if you gave
PMake the
-s flag and no commands will be
echoed. |
.SUFFIXES | This is used to give new file suffixes
for PMake to handle.
Each source is a suffix
PMake should
recognize. If you give a
.SUFFIXES dependency line
with no sources, PMake
will forget about all the suffixes it knew
(this also nukes the null suffix). For those
targets that need to have suffixes defined, this
is how you do it. |
In addition to these targets, a line of the form:
attribute : sources
applies the attribute to all the targets listed as sources.
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