rscons/lib/rscons/environment.rb

310 lines
10 KiB
Ruby

require 'set'
require 'fileutils'
module Rscons
# The Environment class is the main programmatic interface to RScons. It
# contains a collection of construction variables, options, builders, and
# rules for building targets.
class Environment
# Hash of +{"builder_name" => builder_object}+ pairs.
attr_reader :builders
# :command, :short, or :off
attr_accessor :echo
# String or +nil+
attr_reader :build_root
def build_root=(build_root)
@build_root = build_root.gsub('\\', '/')
end
# Create an Environment object.
# @param options [Hash]
# Possible options keys:
# :echo => :command, :short, or :off (default :short)
# :build_root => String specifying build root directory (default nil)
# :exclude_builders => true to omit adding default builders (default false)
# If a block is given, the Environment object is yielded to the block and
# when the block returns, the {#process} method is automatically called.
def initialize(options = {})
@varset = VarSet.new
@targets = {}
@user_deps = {}
@builders = {}
@build_dirs = []
@build_hooks = []
unless options[:exclude_builders]
DEFAULT_BUILDERS.each do |builder_class|
add_builder(builder_class.new)
end
end
@echo = options[:echo] || :short
@build_root = options[:build_root]
if block_given?
yield self
self.process
end
end
# Make a copy of the Environment object.
# The cloned environment will contain a copy of all environment options,
# construction variables, and builders (unless :exclude_builders => true is
# passed as an option). It will not contain a copy of the targets, build
# hooks, build directories, or the build root. If a block is given, the
# Environment object is yielded to the block and when the block returns,
# the {#process} method is automatically called. The possible options keys
# match those documented in the #initialize method.
def clone(options = {})
env = self.class.new(
echo: options[:echo] || @echo,
build_root: options[:build_root],
exclude_builders: true)
unless options[:exclude_builders]
@builders.each do |builder_name, builder|
env.add_builder(builder)
end
end
env.append(@varset.clone)
if block_given?
yield env
env.process
end
env
end
# Add a {Builder} object to the Environment.
def add_builder(builder)
@builders[builder.class.short_name] = builder
var_defs = builder.default_variables(self)
if var_defs
var_defs.each_pair do |var, val|
@varset[var] ||= val
end
end
end
# Add a build hook to the Environment.
def add_build_hook(&block)
@build_hooks << block
end
# Specify a build directory for this Environment.
# Source files from src_dir will produce object files under obj_dir.
def build_dir(src_dir, obj_dir)
src_dir = src_dir.gsub('\\', '/') if src_dir.is_a?(String)
@build_dirs << [src_dir, obj_dir]
end
# Return the file name to be built from source_fname with suffix suffix.
# This method takes into account the Environment's build directories.
def get_build_fname(source_fname, suffix)
build_fname = source_fname.set_suffix(suffix).gsub('\\', '/')
found_match = @build_dirs.find do |src_dir, obj_dir|
if src_dir.is_a?(Regexp)
build_fname.sub!(src_dir, obj_dir)
else
build_fname.sub!(%r{^#{src_dir}/}, "#{obj_dir}/")
end
end
if @build_root and not found_match
unless source_fname.absolute_path? or build_fname.start_with?("#{@build_root}/")
build_fname = "#{@build_root}/#{build_fname}"
end
end
build_fname.gsub!('\\', '/')
build_fname
end
# Access a construction variable or environment option.
# @see VarSet#[]
def [](*args)
@varset.send(:[], *args)
end
# Set a construction variable or environment option.
# @see VarSet#[]=
def []=(*args)
@varset.send(:[]=, *args)
end
# Add a set of construction variables or environment options.
# @see VarSet#append
def append(*args)
@varset.send(:append, *args)
end
# Build all target specified in the Environment.
# When a block is passed to Environment.new, this method is automatically
# called after the block returns.
def process
cache = Cache.new
targets_processed = {}
process_target = proc do |target|
targets_processed[target] ||= begin
@targets[target][:source].each do |src|
if @targets.include?(src) and not targets_processed.include?(src)
process_target.call(src)
end
end
result = run_builder(@targets[target][:builder],
target,
@targets[target][:source],
@user_deps[target] || [],
cache,
@targets[target][:vars] || {})
unless result
cache.write
raise BuildError.new("Failed to build #{target}")
end
result
end
end
@targets.each do |target, info|
process_target.call(target)
end
cache.write
end
# Clear all targets registered for the Environment.
def clear_targets
@targets = {}
end
# Build a command line from the given template, resolving references to
# variables using the Environment's construction variables and any extra
# variables specified.
# @param command_template [Array] template for the command with variable
# references
# @param extra_vars [Hash, VarSet] extra variables to use in addition to
# (or replace) the Environment's construction variables when building
# the command
def build_command(command_template, extra_vars)
@varset.merge(extra_vars).expand_varref(command_template)
end
# Execute a builder command
# @param short_desc [String] Message to print if the Environment's echo
# mode is set to :short
# @param command [Array] The command to execute.
# @param options [Hash] Optional options to pass to Kernel#system.
def execute(short_desc, command, options = {})
print_command = proc do
puts command.map { |c| c =~ /\s/ ? "'#{c}'" : c }.join(' ')
end
if @echo == :command
print_command.call
elsif @echo == :short
puts short_desc
end
system(*command, options).tap do |result|
unless result or @echo == :command
$stdout.write "Failed command was: "
print_command.call
end
end
end
alias_method :orig_method_missing, :method_missing
def method_missing(method, *args)
if @builders.has_key?(method.to_s)
target, source, vars, *rest = args
unless vars.nil? or vars.is_a?(Hash) or vars.is_a?(VarSet)
raise "Unexpected construction variable set: #{vars.inspect}"
end
source = [source] unless source.is_a?(Array)
@targets[target] = {
builder: @builders[method.to_s],
source: source,
vars: vars,
args: rest,
}
else
orig_method_missing(method, *args)
end
end
# Manually record a given target as depending on the specified
# dependency files.
def depends(target, *user_deps)
@user_deps[target] ||= []
@user_deps[target] = (@user_deps[target] + user_deps).uniq
end
# Build a list of source files into files containing one of the suffixes
# given by suffixes.
# This method is used internally by RScons builders.
# @param sources [Array] List of source files to build.
# @param suffixes [Array] List of suffixes to try to convert source files into.
# @param cache [Cache] The Cache.
# @param vars [Hash] Extra variables to pass to the builder.
# Return a list of the converted file names.
def build_sources(sources, suffixes, cache, vars)
sources.map do |source|
if source.has_suffix?(suffixes)
source
else
converted = nil
suffixes.each do |suffix|
converted_fname = get_build_fname(source, suffix)
builder = @builders.values.find { |b| b.produces?(converted_fname, source, self) }
if builder
converted = run_builder(builder, converted_fname, [source], [], cache, vars)
return nil unless converted
break
end
end
converted or raise "Could not find a builder to handle #{source.inspect}."
end
end
end
# Invoke a builder to build the given target based on the given sources.
# @param builder [Builder] The Builder to use.
# @param target [String] The target output file.
# @param sources [Array] List of source files.
# @param cache [Cache] The Cache.
# @param vars [Hash] Extra variables to pass to the builder.
# Return the result of the builder's run() method.
def run_builder(builder, target, sources, user_deps, cache, vars)
vars = @varset.merge(vars)
@build_hooks.each do |build_hook_block|
build_operation = {
builder: builder,
target: target,
sources: sources,
user_deps: user_deps,
vars: vars,
}
build_hook_block.call(build_operation)
end
builder.run(target, sources, user_deps, cache, self, vars)
end
# Parse dependencies for a given target from a Makefile.
# This method is used internally by RScons builders.
# @param mf_fname [String] File name of the Makefile to read.
# @param target [String] Name of the target to gather dependencies for.
def self.parse_makefile_deps(mf_fname, target)
deps = []
buildup = ''
File.read(mf_fname).each_line do |line|
if line =~ /^(.*)\\\s*$/
buildup += ' ' + $1
else
buildup += ' ' + line
if buildup =~ /^(.*): (.*)$/
mf_target, mf_deps = $1.strip, $2
if mf_target == target
deps += mf_deps.split(' ').map(&:strip)
end
end
buildup = ''
end
end
deps
end
end
end