GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages
Makefile::AST::Evaluator(3) User Contributed Perl Documentation Makefile::AST::Evaluator(3)
 

Makefile::AST::Evaluator - Evaluator and runtime for Makefile::AST instances

    use Makefile::AST::Evaluator;
    $Makefile::AST::Evaluator::JustPrint = 0;
    $Makefile::AST::Evaluator::Quiet = 1;
    $Makefile::AST::Evaluator::IgnoreErrors = 1;
    $Makefile::AST::Evaluator::AlwaysMake = 1;
    $Makefile::AST::Evaluator::Question = 1;
    # $ast is a Makefile::AST instance:
    my $eval = Makefile::AST::Evaluator->new($ast);
    Makefile::AST::Evaluator->add_trigger(
        firing_rule => sub {
            my ($self, $rule, $ast_cmds) = @_;
            my $target = $rule->target;
            my $colon = $rule->colon;
            my @normal_prereqs = @{ $rule->normal_prereqs };
            # ...
        }
    );
    $eval->set_required_target($user_makefile)
    $eval->make($goal);

This module implementes an evaluator or a runtime for makefile ASTs represented by Makefile::AST instances.
It "executes" the specified GNU make AST by the GNU makefile semantics. Note that, "execution" not necessarily mean building a project tree by firing makefile rule commands. Actually you can defining your own triggers by calling the add_trigger method. (See the "SYNOPSIS" for examples.) In other words, you can do more interesting things like plotting the call path tree of a Makefile using Graphviz, or translating the original makefile to another form (like what the makesimple script does).
It's worth mentioning that, most of the construction algorithm for topological graph s (including implicit rule application) have already been implemented in Makefile::AST and its child node classes.

This module provides several package variables (i.e. static class variables) for controlling the behavior of the evaluator.
Particularly the user needs to set the $AlwaysMake variable to true and $Question to true, if she wants to use the evaluator to do special tasks like plotting dependency graphs and translating GNU makefiles to other format.
Setting $AlwaysMake to true will force the evaluator to ignore the timestamps of external files appeared in the makefiles while setting $Question to true will prevent the evaluator from executing the shell commands specified in the makefile rules.
Here's the detailed listing for all the config variables:
$Question
This variable corresponds to the command-line option "-q" or <--question> in GNU make. Its purpose is to make the evaluator enter the "questioning mode", i.e., a mode in which "make" will never try executing rule commands unless it has to, "and" echoing is suppressed at the same time.
$AlwaysMake
This variable corresponds to the command-line option "-B" or "--always-make". It forces re-constructing all the rule's targets related to the goal, ignoring the timestamp or existence of targets' dependencies.
$Quiet
It corresponds to GNU make's command-line option "-s", "--silent", or "--quiet". Its effect is to cancel the echoing of shell commands being executed.
$JustPrint
This variable corresponds to GNU make's command line option "-n", "--just-print", "--dry-run", or "--recon". Its effect is to print out the shell commands requiring execution but without actually executing them.
$IgnoreErrors
This variable corresponds to GNU make's command line option "-i" or "--ignore-errors". It's used to ignore the errors of shell commands being executed during the make process. The default behavior is quitting as soon as a shell command without the "-" modifier fails.

The "make_by_rule" method of this class defines a trigger named "firing_rule" via the Class::Trait module. Everytime the "make_by_rule" method reaches the trigger point, it will invoke the user's processing handler with the following three arguments: the self object, the Makefile::AST::Rule object, and the corresponding "Makefile::AST::Command" object in the context.
By registering his own processing handlers for the "firing_rule" trigger, the user's code can reuse the evaluator to do his own cool things without traversing the makefile ASTs himself.
See the "SYNOPSIS" for code examples.

For the very latest version of this script, check out the source from
<http://github.com/agentzh/makefile-parser-pm>.
There is anonymous access to all.

Zhang "agentzh" Yichun "<agentzh@gmail.com>"

Copyright (c) 2007-2008 by Zhang "agentzh" Yichun (agentzh).
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

Makefile::AST, Makefile::Parser::GmakeDB, pgmake-db, makesimple, Makefile::DOM.
2014-11-19 perl v5.28.1

Search for    or go to Top of page |  Section 3 |  Main Index

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with ManDoc.