v1.9.2

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    rscons (1.8.0)
+    rscons (1.9.2)
       json (~> 1.0)
 
 GEM
@@ -9,30 +9,30 @@ GEM
   specs:
     diff-lcs (1.2.5)
     docile (1.1.5)
-    json (1.8.1)
+    json (1.8.3)
-    multi_json (1.10.1)
+    rake (10.4.2)
-    rake (10.3.2)
+    rdoc (4.2.0)
-    rdoc (4.1.2)
       json (~> 1.4)
-    redcarpet (3.1.2)
+    redcarpet (3.3.3)
-    rspec (3.0.0)
+    rspec (3.4.0)
-      rspec-core (~> 3.0.0)
+      rspec-core (~> 3.4.0)
-      rspec-expectations (~> 3.0.0)
+      rspec-expectations (~> 3.4.0)
-      rspec-mocks (~> 3.0.0)
+      rspec-mocks (~> 3.4.0)
-    rspec-core (3.0.1)
+    rspec-core (3.4.1)
-      rspec-support (~> 3.0.0)
+      rspec-support (~> 3.4.0)
-    rspec-expectations (3.0.1)
+    rspec-expectations (3.4.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.0.0)
+      rspec-support (~> 3.4.0)
-    rspec-mocks (3.0.1)
+    rspec-mocks (3.4.0)
-      rspec-support (~> 3.0.0)
+      diff-lcs (>= 1.2.0, < 2.0)
-    rspec-support (3.0.0)
+      rspec-support (~> 3.4.0)
-    simplecov (0.8.2)
+    rspec-support (3.4.1)
+    simplecov (0.11.1)
       docile (~> 1.1.0)
-      multi_json
+      json (~> 1.8)
-      simplecov-html (~> 0.8.0)
+      simplecov-html (~> 0.10.0)
-    simplecov-html (0.8.0)
+    simplecov-html (0.10.0)
-    yard (0.8.7.4)
+    yard (0.8.7.6)
 
 PLATFORMS
   ruby
@@ -46,3 +46,6 @@ DEPENDENCIES
   rspec
   simplecov
   yard
+
+BUNDLED WITH
+   1.10.6

README.md

@@ -1,6 +1,7 @@
 # Rscons
 
-Software construction library inspired by SCons and implemented in Ruby
+Rscons is a software construction framework inspired by SCons and implemented
+in Ruby.
 
 [![Gem Version](https://badge.fury.io/rb/rscons.png)](http://badge.fury.io/rb/rscons)
 
@@ -20,9 +21,10 @@ Or install it yourself as:
 
 ## Usage
 
-Rscons is a Ruby library.
+Rscons is implemented as a Ruby library and distributed as a gem.
-It can be called from a standalone Ruby script or it can be used with rake and
+It also provides a "rscons" executable which can evaluate a build script (by
-called from your Rakefile.
+default named Rsconsfile or Rsconsfile.rb).
+It can also be used from rake or from a standalone Ruby script.
 
 ### Example: Building a C Program
 
@@ -235,13 +237,15 @@ end
 
 Rscons ships with a number of builders:
 
-* Command, which executes a user-defined command to produce the target
+* Command, which executes a user-defined command to produce the target.
-* CFile, which builds a C or C++ source file from a lex or yacc input file
+* Copy, which is identical to Install.
-* Disassemble, which disassembles an object file to a disassembly listing
+* CFile, which builds a C or C++ source file from a lex or yacc input file.
-* Library, which collects object files into a static library archive file
+* Disassemble, which disassembles an object file to a disassembly listing.
-* Object, which compiles source files to produce an object file
+* Install, which installs files or directories to a specified destination.
-* Preprocess, which invokes the C/C++ preprocessor on a source file
+* Library, which collects object files into a static library archive file.
-* Program, which links object files to produce an executable
+* Object, which compiles source files to produce an object file.
+* Preprocess, which invokes the C/C++ preprocessor on a source file.
+* Program, which links object files to produce an executable.
 
 If you want to create an Environment that does not contain any builders,
 you can use the `exclude_builders` key to the Environment constructor.
@@ -249,10 +253,11 @@ you can use the `exclude_builders` key to the Environment constructor.
 #### Command
 
 ```ruby
-env.Command(target, sources, 'CMD' => command)
+env.Command(target, sources, "CMD" => command)
 # Example
 env.Command("docs.html", "docs.md",
-    CMD => ['pandoc', '-fmarkdown', '-thtml', '-o${_TARGET}', '${_SOURCES}'])
+    "CMD" => ["pandoc", "-fmarkdown", "-thtml", "-o${_TARGET}", "${_SOURCES}"],
+    "CMD_DESC" => "PANDOC")
 ```
 
 The command builder executes a user-defined command in order to produce the
@@ -280,6 +285,15 @@ env.Disassemble("module.dis", "module.o")
 The Disassemble builder generates a disassembly listing using objdump from
 and object file.
 
+#### Install
+
+```ruby
+env.Install(destination, sources)
+# Example
+env.Install("dist/bin", "app.exe")
+env.Install("dist/share", "share")
+```
+
 #### Library
 
 ```ruby
@@ -371,6 +385,15 @@ Post-build hooks are only invoked if the build operation was a success.
 Post-build hooks can invoke commands using the newly-built files, or register
 new build targets.
 
+### Phony Targets
+
+A build target name given as a Symbol instead of a String is interpreted as a
+"phony" target.
+Phony targets operate similarly to normal build targets, except that a file is
+not expected to be produced by the builder.
+Phony targets will still be "rebuilt" if any source or the command is out of
+date.
+
 ### Construction Variable Naming
 
 * uppercase strings - the default construction variables that Rscons uses
@@ -383,6 +406,38 @@ http://rubydoc.info/github/holtrop/rscons/frames.
 
 ## Release Notes
 
+### v1.9.2
+
+- allow phony targets in conjunction with build roots
+
+### v1.9.1
+
+- change *SUFFIX defaults to arrays
+- add various C++ file suffixes
+- use ${INCPREFIX} instead of hard-coded "-I" in Preprocess builder
+
+### v1.9.0
+
+#### New Features
+
+- #6 - add Install and Copy builders
+- #22 - allow overriding Command builder short description with CMD_DESC variable
+- #24 - add "rscons" executable
+- #25 - add support for phony targets given as Symbols instead of Strings
+- #26 - support registering multiple build targets with the same target name
+- #27 - add Directory builder
+
+#### Fixes
+
+- #20 - fix variable references that expand to arrays in build target sources
+- #21 - rework Preprocess builder to consider deep dependencies
+- fix Rscons.set_suffix to append the given suffix if the filename has none
+- remove ${CFLAGS} from default CPP_CMD
+
+### v1.8.1
+
+- fix Environment#dump when construction variables are symbols
+
 ### v1.8.0
 
 - new Command builder to execute arbitrary user commands

Rakefile.rb

@@ -13,7 +13,11 @@ require "rake/clean"
 CLEAN.include %w[build_test_run .yardoc doc coverage]
 CLOBBER.include %w[pkg]
 
-RSpec::Core::RakeTask.new(:spec)
+RSpec::Core::RakeTask.new(:spec, :example_string) do |task, args|
+  if args.example_string
+    task.rspec_opts = %W[-e "#{args.example_string}" -f documentation]
+  end
+end
 
 YARD::Rake::YardocTask.new do |yard|
   yard.files = ['lib/**/*.rb']

bin/rscons

@@ -0,0 +1,3 @@
+require "rscons/cli"
+
+Rscons::Cli.run(ARGV)

build_tests/preprocess/bar.h

@@ -0,0 +1 @@
+#define BAR xyz42abc

build_tests/preprocess/foo.h

@@ -0,0 +1,2 @@
+#include "bar.h"
+BAR

lib/rscons.rb

@@ -6,9 +6,11 @@ require_relative "rscons/varset"
 require_relative "rscons/version"
 
 # default builders
-require_relative "rscons/builders/command"
 require_relative "rscons/builders/cfile"
+require_relative "rscons/builders/command"
+require_relative "rscons/builders/directory"
 require_relative "rscons/builders/disassemble"
+require_relative "rscons/builders/install"
 require_relative "rscons/builders/library"
 require_relative "rscons/builders/object"
 require_relative "rscons/builders/preprocess"
@@ -17,12 +19,16 @@ require_relative "rscons/builders/simple_builder"
 
 # Namespace module for rscons classes
 module Rscons
+
   # Names of the default builders which will be added to all newly created
   # {Environment} objects.
   DEFAULT_BUILDERS = [
-    :Command,
     :CFile,
+    :Command,
+    :Copy,
+    :Directory,
     :Disassemble,
+    :Install,
     :Library,
     :Object,
     :Preprocess,
@@ -32,101 +38,114 @@ module Rscons
   # Class to represent a fatal error while building a target.
   class BuildError < RuntimeError; end
 
-  # Remove all generated files.
+  class << self
-  #
+
-  # @return [void]
+    # Remove all generated files.
-  def self.clean
+    #
-    cache = Cache.instance
+    # @return [void]
-    # remove all built files
+    def clean
-    cache.targets.each do |target|
+      cache = Cache.instance
-      FileUtils.rm_f(target)
+      # remove all built files
-    end
+      cache.targets.each do |target|
-    # remove all created directories if they are empty
+        FileUtils.rm_f(target)
-    cache.directories.sort {|a, b| b.size <=> a.size}.each do |directory|
-      next unless File.directory?(directory)
-      if (Dir.entries(directory) - ['.', '..']).empty?
-        Dir.rmdir(directory) rescue nil
       end
-    end
+      # remove all created directories if they are empty
-    cache.clear
+      cache.directories.sort {|a, b| b.size <=> a.size}.each do |directory|
-  end
+        next unless File.directory?(directory)
-
+        if (Dir.entries(directory) - ['.', '..']).empty?
-  # Return whether the given path is an absolute filesystem path.
+          Dir.rmdir(directory) rescue nil
-  #
-  # @param path [String] the path to examine.
-  #
-  # @return [Boolean] Whether the given path is an absolute filesystem path.
-  def self.absolute_path?(path)
-    path =~ %r{^(/|\w:[\\/])}
-  end
-
-  # Return a new path by changing the suffix in path to suffix.
-  #
-  # @param path [String] The path to alter.
-  # @param suffix [String] The new filename suffix, e.g. ".exe".
-  #
-  # @return [String] New path.
-  def self.set_suffix(path, suffix)
-    path.sub(/\.[^.]*$/, suffix)
-  end
-
-  # Return the system shell and arguments for executing a shell command.
-  #
-  # @return [Array<String>] The shell and flag.
-  def self.get_system_shell
-    @@shell ||=
-      begin
-        test_shell = lambda do |*args|
-          begin
-            "success" == IO.popen([*args, "echo success"]) do |io|
-              io.read.strip
-            end
-          rescue
-            false
-          end
         end
-        if ENV["SHELL"] and ENV["SHELL"] != "" and test_shell[ENV["SHELL"], "-c"]
+      end
-          [ENV["SHELL"], "-c"]
+      cache.clear
-        elsif Object.const_get("RUBY_PLATFORM") =~ /mingw/
+    end
-          if test_shell["sh", "-c"]
+
-            # Using Rscons from MSYS should use MSYS's shell.
+    # Return whether the given path is an absolute filesystem path.
-            ["sh", "-c"]
+    #
+    # @param path [String] the path to examine.
+    #
+    # @return [Boolean] Whether the given path is an absolute filesystem path.
+    def absolute_path?(path)
+      path =~ %r{^(/|\w:[\\/])}
+    end
+
+    # Return whether the given target is a phony target.
+    #
+    # @param target [Symbol, String] Target name.
+    #
+    # @return [Boolean] Whether the given target is a phony target.
+    def phony_target?(target)
+      target.is_a?(Symbol)
+    end
+
+    # Return a new path by changing the suffix in path to suffix.
+    #
+    # @param path [String] The path to alter.
+    # @param suffix [String] The new filename suffix, e.g. ".exe".
+    #
+    # @return [String] New path.
+    def set_suffix(path, suffix)
+      path.sub(/\.[^.]*$/, "") + suffix
+    end
+
+    # Return the system shell and arguments for executing a shell command.
+    #
+    # @return [Array<String>] The shell and flag.
+    def get_system_shell
+      @shell ||=
+        begin
+          test_shell = lambda do |*args|
+            begin
+              "success" == IO.popen([*args, "echo success"]) do |io|
+                io.read.strip
+              end
+            rescue
+              false
+            end
+          end
+          if ENV["SHELL"] and ENV["SHELL"] != "" and test_shell[ENV["SHELL"], "-c"]
+            [ENV["SHELL"], "-c"]
+          elsif Object.const_get("RUBY_PLATFORM") =~ /mingw/
+            if test_shell["sh", "-c"]
+              # Using Rscons from MSYS should use MSYS's shell.
+              ["sh", "-c"]
+            else
+              ["cmd", "/c"]
+            end
           else
-            ["cmd", "/c"]
+            ["sh", "-c"]
           end
-        else
-          ["sh", "-c"]
         end
-      end
+    end
-  end
 
-  # Return an Array containing a command used to execute commands.
+    # Return an Array containing a command used to execute commands.
-  #
+    #
-  # This will normally be an empty Array, but on Windows if Rscons detects
+    # This will normally be an empty Array, but on Windows if Rscons detects
-  # that it is running in MSYS then ["env"] will be returned.
+    # that it is running in MSYS then ["env"] will be returned.
-  #
+    #
-  # @return [Array<String>] Command used to execute commands.
+    # @return [Array<String>] Command used to execute commands.
-  def self.command_executer
+    def command_executer
-    @@command_executer ||=
+      @command_executer ||=
-      if Object.const_get("RUBY_PLATFORM") =~ /mingw/
+        if Object.const_get("RUBY_PLATFORM") =~ /mingw/
-        if ENV.keys.find {|key| key =~ /MSYS/}
+          if ENV.keys.find {|key| key =~ /MSYS/}
-          begin
+            begin
-            if IO.popen(["env", "echo", "success"]) {|io| io.read.strip} == "success"
+              if IO.popen(["env", "echo", "success"]) {|io| io.read.strip} == "success"
-              ["env"]
+                ["env"]
+              end
+            rescue
             end
-          rescue
           end
-        end
+        end || []
-      end || []
+    end
-  end
+
+    # Set the command executer array.
+    #
+    # @param val [Array<String>] Command used to execute commands.
+    #
+    # @return [Array<String>] Command used to execute commands.
+    def command_executer=(val)
+      @command_executer = val
+    end
 
-  # Set the command executer array.
-  #
-  # @param val [Array<String>] Command used to execute commands.
-  #
-  # @return [Array<String>] Command used to execute commands.
-  def self.command_executer=(val)
-    @@command_executer = val
   end
 end
 

lib/rscons/builder.rb

@@ -87,8 +87,10 @@ module Rscons
     #   The name of the target on success or false on failure.
     def standard_build(short_cmd_string, target, command, sources, env, cache)
       unless cache.up_to_date?(target, command, sources, env)
-        cache.mkdir_p(File.dirname(target))
+        unless Rscons.phony_target?(target)
-        FileUtils.rm_f(target)
+          cache.mkdir_p(File.dirname(target))
+          FileUtils.rm_f(target)
+        end
         return false unless env.execute(short_cmd_string, command)
         cache.register_build(target, command, sources, env)
       end

lib/rscons/builders/command.rb

@@ -25,7 +25,8 @@ module Rscons
           "_SOURCES" => sources,
         })
         command = env.build_command("${CMD}", vars)
-        standard_build("CMD #{target}", target, command, sources, env, cache)
+        cmd_desc = vars["CMD_DESC"] || "Command"
+        standard_build("#{cmd_desc} #{target}", target, command, sources, env, cache)
       end
     end
   end

lib/rscons/builders/directory.rb

@@ -0,0 +1,31 @@
+module Rscons
+  module Builders
+    # The Directory builder creates a directory.
+    class Directory < Builder
+
+      # Run the builder to produce a build target.
+      #
+      # @param target [String] Target file name.
+      # @param sources [Array<String>] Source file name(s).
+      # @param cache [Cache] The Cache object.
+      # @param env [Environment] The Environment executing the builder.
+      # @param vars [Hash,VarSet] Extra construction variables.
+      #
+      # @return [String,false]
+      #   Name of the target file on success or false on failure.
+      def run(target, sources, cache, env, vars)
+        if File.directory?(target)
+          target
+        elsif File.exists?(target)
+          $stderr.puts "Error: `#{target}' already exists and is not a directory"
+          false
+        else
+          puts "Directory #{target}"
+          cache.mkdir_p(target)
+          target
+        end
+      end
+
+    end
+  end
+end

lib/rscons/builders/install.rb

@@ -0,0 +1,64 @@
+require "pathname"
+
+module Rscons
+  module Builders
+    # The Install builder copies files/directories to new locations.
+    class Install < Builder
+
+      # Run the builder to produce a build target.
+      #
+      # @param target [String] Target file name.
+      # @param sources [Array<String>] Source file name(s).
+      # @param cache [Cache] The Cache object.
+      # @param env [Environment] The Environment executing the builder.
+      # @param vars [Hash,VarSet] Extra construction variables.
+      #
+      # @return [String,false]
+      #   Name of the target file on success or false on failure.
+      def run(target, sources, cache, env, vars)
+        target_is_dir = (sources.length > 1) ||
+                        Dir.exists?(sources.first) ||
+                        Dir.exists?(target)
+        outdir = target_is_dir ? target : File.dirname(target)
+        # Collect the list of files to copy over.
+        file_map = {}
+        if target_is_dir
+          sources.each do |src|
+            if Dir.exists? src
+              Dir.glob("#{src}/**/*", File::FNM_DOTMATCH).select do |f|
+                File.file?(f)
+              end.each do |subfile|
+                subpath = Pathname.new(subfile).relative_path_from(Pathname.new(src)).to_s
+                file_map[subfile] = "#{outdir}/#{subpath}"
+              end
+            else
+              file_map[src] = "#{outdir}/#{File.basename(src)}"
+            end
+          end
+        else
+          file_map[sources.first] = target
+        end
+        printed_message = false
+        file_map.each do |src, dest|
+          # Check the cache and copy if necessary
+          unless cache.up_to_date?(dest, :Copy, [src], env)
+            unless printed_message
+              puts "#{name} #{target}"
+              printed_message = true
+            end
+            cache.mkdir_p(File.dirname(dest))
+            FileUtils.cp(src, dest, :preserve => true)
+          end
+          cache.register_build(dest, :Copy, [src], env)
+        end
+        target if (target_is_dir ? Dir.exists?(target) : File.exists?(target))
+      end
+
+
+    end
+
+    # The Copy builder is identical to the Install builder.
+    class Copy < Install; end
+
+  end
+end

lib/rscons/builders/object.rb

@@ -18,7 +18,7 @@ module Rscons
       # @return [Hash] Default construction variables for the builder.
       def default_variables(env)
         {
-          'OBJSUFFIX' => '.o',
+          'OBJSUFFIX' => ['.o'],
           'DEPFILESUFFIX' => '.mf',
 
           'CPPDEFPREFIX' => '-D',
@@ -26,7 +26,7 @@ module Rscons
 
           'AS' => '${CC}',
           'ASFLAGS' => [],
-          'ASSUFFIX' => '.S',
+          'ASSUFFIX' => ['.S'],
           'ASPPPATH' => '${CPPPATH}',
           'ASPPFLAGS' => '${CPPFLAGS}',
           'ASDEPGEN' => ['-MMD', '-MF', '${_DEPFILE}'],
@@ -40,19 +40,19 @@ module Rscons
 
           'CC' => 'gcc',
           'CFLAGS' => [],
-          'CSUFFIX' => '.c',
+          'CSUFFIX' => ['.c'],
           'CCDEPGEN' => ['-MMD', '-MF', '${_DEPFILE}'],
           'CCCMD' => ['${CC}', '-c', '-o', '${_TARGET}', '${CCDEPGEN}', '${INCPREFIX}${CPPPATH}', '${CPPFLAGS}', '${CFLAGS}', '${CCFLAGS}', '${_SOURCES}'],
 
           'CXX' => 'g++',
           'CXXFLAGS' => [],
-          'CXXSUFFIX' => '.cc',
+          'CXXSUFFIX' => ['.cc', '.cpp', '.cxx', '.C'],
           'CXXDEPGEN' => ['-MMD', '-MF', '${_DEPFILE}'],
           'CXXCMD' =>['${CXX}', '-c', '-o', '${_TARGET}', '${CXXDEPGEN}', '${INCPREFIX}${CPPPATH}', '${CPPFLAGS}', '${CXXFLAGS}', '${CCFLAGS}', '${_SOURCES}'],
 
           'DC' => 'gdc',
           'DFLAGS' => [],
-          'DSUFFIX' => '.d',
+          'DSUFFIX' => ['.d'],
           'D_IMPORT_PATH' => [],
           'DCCMD' => ['${DC}', '-c', '-o', '${_TARGET}', '${INCPREFIX}${D_IMPORT_PATH}', '${DFLAGS}', '${_SOURCES}'],
         }

lib/rscons/builders/preprocess.rb

@@ -1,7 +1,10 @@
+require "fileutils"
+
 module Rscons
   module Builders
     # The Preprocess builder invokes the C preprocessor
     class Preprocess < Builder
+
       # Return default construction variables for the builder.
       #
       # @param env [Environment] The Environment using the builder.
@@ -9,7 +12,9 @@ module Rscons
       # @return [Hash] Default construction variables for the builder.
       def default_variables(env)
         {
-          "CPP_CMD" => ["${_PREPROCESS_CC}", "-E", "-o", "${_TARGET}", "-I${CPPPATH}", "${CPPFLAGS}", "${CFLAGS}", "${_SOURCES}"],
+          "CPP_CMD" => %w[
+            ${_PREPROCESS_CC} -E ${_PREPROCESS_DEPGEN}
+            -o ${_TARGET} ${INCPREFIX}${CPPPATH} ${CPPFLAGS} ${_SOURCES}],
         }
       end
 
@@ -24,17 +29,32 @@ module Rscons
       # @return [String,false]
       #   Name of the target file on success or false on failure.
       def run(target, sources, cache, env, vars)
-        pp_cc = if sources.find {|s| s.end_with?(*env.expand_varref("${CXXSUFFIX}", vars))}
+        if sources.find {|s| s.end_with?(*env.expand_varref("${CXXSUFFIX}", vars))}
-                  "${CXX}"
+          pp_cc = "${CXX}"
-                else
+          depgen = "${CXXDEPGEN}"
-                  "${CC}"
+        else
-                end
+          pp_cc = "${CC}"
+          depgen = "${CCDEPGEN}"
+        end
         vars = vars.merge("_PREPROCESS_CC" => pp_cc,
+                          "_PREPROCESS_DEPGEN" => depgen,
                           "_TARGET" => target,
-                          "_SOURCES" => sources)
+                          "_SOURCES" => sources,
+                          "_DEPFILE" => Rscons.set_suffix(target, env.expand_varref("${DEPFILESUFFIX}", vars)))
         command = env.build_command("${CPP_CMD}", vars)
-        standard_build("Preprocess #{target}", target, command, sources, env, cache)
+        unless cache.up_to_date?(target, command, sources, env)
+          cache.mkdir_p(File.dirname(target))
+          return false unless env.execute("Preprocess #{target}", command)
+          deps = sources
+          if File.exists?(vars["_DEPFILE"])
+            deps += Environment.parse_makefile_deps(vars["_DEPFILE"], nil)
+            FileUtils.rm_f(vars["_DEPFILE"])
+          end
+          cache.register_build(target, command, deps.uniq, env)
+        end
+        target
       end
+
     end
   end
 end

lib/rscons/cache.rb

@@ -56,6 +56,9 @@ module Rscons
     # Name of the file to store cache information in
     CACHE_FILE = ".rsconscache"
 
+    # Prefix for phony cache entries.
+    PHONY_PREFIX = ":PHONY:"
+
     # Create a Cache object and load in the previous contents from the cache
     # file.
     def initialize
@@ -92,7 +95,8 @@ module Rscons
 
     # Check if target(s) are up to date.
     #
-    # @param targets [String, Array<String>] The name(s) of the target file(s).
+    # @param targets [Symbol, String, Array<String>]
+    #   The name(s) of the target file(s).
     # @param command [String, Array, Hash]
     #   The command used to build the target. The command parameter can
     #   actually be a String, Array, or Hash and could contain information
@@ -120,19 +124,25 @@ module Rscons
     #     stored in the cache file
     def up_to_date?(targets, command, deps, env, options = {})
       Array(targets).each do |target|
-        # target file must exist on disk
+        cache_key = get_cache_key(target)
-        return false unless File.exists?(target)
+
+        unless Rscons.phony_target?(target)
+          # target file must exist on disk
+          return false unless File.exists?(target)
+        end
 
         # target must be registered in the cache
-        return false unless @cache["targets"].has_key?(target)
+        return false unless @cache["targets"].has_key?(cache_key)
 
-        # target must have the same checksum as when it was built last
+        unless Rscons.phony_target?(target)
-        return false unless @cache["targets"][target]["checksum"] == lookup_checksum(target)
+          # target must have the same checksum as when it was built last
+          return false unless @cache["targets"][cache_key]["checksum"] == lookup_checksum(target)
+        end
 
         # command used to build target must be identical
-        return false unless @cache["targets"][target]["command"] == Digest::MD5.hexdigest(command.inspect)
+        return false unless @cache["targets"][cache_key]["command"] == Digest::MD5.hexdigest(command.inspect)
 
-        cached_deps = @cache["targets"][target]["deps"] || []
+        cached_deps = @cache["targets"][cache_key]["deps"] || []
         cached_deps_fnames = cached_deps.map { |dc| dc["fname"] }
         if options[:strict_deps]
           # depedencies passed in must exactly equal those in the cache
@@ -144,7 +154,7 @@ module Rscons
 
         # set of user dependencies must match
         user_deps = env.get_user_deps(target) || []
-        cached_user_deps = @cache["targets"][target]["user_deps"] || []
+        cached_user_deps = @cache["targets"][cache_key]["user_deps"] || []
         cached_user_deps_fnames = cached_user_deps.map { |dc| dc["fname"] }
         return false unless user_deps == cached_user_deps_fnames
 
@@ -159,7 +169,8 @@ module Rscons
 
     # Store cache information about target(s) built by a builder.
     #
-    # @param targets [String, Array<String>] The name of the target(s) built.
+    # @param targets [Symbol, String, Array<String>]
+    #   The name of the target(s) built.
     # @param command [String, Array, Hash]
     #   The command used to build the target. The command parameter can
     #   actually be a String, Array, or Hash and could contain information
@@ -172,9 +183,10 @@ module Rscons
     # @return [void]
     def register_build(targets, command, deps, env)
       Array(targets).each do |target|
-        @cache["targets"][target] = {
+        target_checksum = Rscons.phony_target?(target) ? "" : calculate_checksum(target)
+        @cache["targets"][get_cache_key(target)] = {
           "command" => Digest::MD5.hexdigest(command.inspect),
-          "checksum" => calculate_checksum(target),
+          "checksum" => target_checksum,
           "deps" => deps.map do |dep|
             {
               "fname" => dep,
@@ -228,6 +240,21 @@ module Rscons
 
     private
 
+    # Return a String key based on the target name to use in the on-disk cache.
+    #
+    # @param target_name [Symbol, String]
+    #   Target name.
+    #
+    # @return [String]
+    #   Key name.
+    def get_cache_key(target_name)
+      if Rscons.phony_target?(target_name)
+        PHONY_PREFIX + target_name.to_s
+      else
+        target_name
+      end
+    end
+
     # Create a Cache object and load in the previous contents from the cache
     # file.
     def initialize!

lib/rscons/cli.rb

@@ -0,0 +1,78 @@
+require "rscons"
+require "optparse"
+
+module Rscons
+  # Command-Line Interface functionality.
+  module Cli
+
+    # Default files to look for to execute if none specified.
+    DEFAULT_RSCONSFILES = %w[Rsconsfile Rsconsfile.rb]
+
+    class << self
+
+      # Run the Rscons CLI.
+      #
+      # @param argv [Array]
+      #   Command-line parameters.
+      #
+      # @return [void]
+      def run(argv)
+        argv = argv.dup
+        rsconsfile = nil
+
+        OptionParser.new do |opts|
+          opts.banner = "Usage: #{$0} [options]"
+
+          opts.separator ""
+          opts.separator "Options:"
+
+          opts.on("-c", "--clean", "Perform clean operation") do
+            Rscons.clean
+            exit 0
+          end
+
+          opts.on("-f FILE", "Execute FILE (default Rsconsfile)") do |f|
+            rsconsfile = f
+          end
+
+          opts.on_tail("--version", "Show version") do
+            puts "Rscons version #{Rscons::VERSION}"
+            exit 0
+          end
+
+          opts.on_tail("-h", "--help", "Show this help.") do
+            puts opts
+            exit 0
+          end
+
+        end.parse!(argv)
+
+        if rsconsfile
+          unless File.exists?(rsconsfile)
+            $stderr.puts "Cannot read #{rsconsfile}"
+            exit 1
+          end
+        else
+          rsconsfile = DEFAULT_RSCONSFILES.find do |f|
+            File.exists?(f)
+          end
+          unless rsconsfile
+            $stderr.puts "Could not find the Rsconsfile to execute."
+            $stderr.puts "Looked in: [#{DEFAULT_RSCONSFILES.join(", ")}]"
+            exit 1
+          end
+        end
+
+        begin
+          load rsconsfile
+        rescue Rscons::BuildError => e
+          $stderr.puts e.message
+          exit 1
+        end
+
+        exit 0
+      end
+
+    end
+  end
+end

lib/rscons/environment.rb

@@ -280,33 +280,35 @@ module Rscons
     #
     # @return [void]
     def process
-      expand_paths!
       while @targets.size > 0
+        expand_paths!
         targets = @targets
         @targets = {}
         cache = Cache.instance
         cache.clear_checksum_cache!
-        targets_processed = {}
+        targets_processed = Set.new
         process_target = proc do |target|
-          targets_processed[target] ||= begin
+          unless targets_processed.include?(target)
-            targets[target][:sources].each do |src|
+            targets_processed << target
-              if targets.include?(src) and not targets_processed.include?(src)
+            targets[target].each do |target_params|
-                process_target.call(src)
+              target_params[:sources].each do |src|
+                if targets.include?(src) and not targets_processed.include?(src)
+                  process_target.call(src)
+                end
+              end
+              result = run_builder(target_params[:builder],
+                                   target,
+                                   target_params[:sources],
+                                   cache,
+                                   target_params[:vars] || {})
+              unless result
+                raise BuildError.new("Failed to build #{target}")
               end
             end
-            result = run_builder(targets[target][:builder],
-                                 target,
-                                 targets[target][:sources],
-                                 cache,
-                                 targets[target][:vars] || {})
-            unless result
-              raise BuildError.new("Failed to build #{target}")
-            end
-            result
           end
         end
         begin
-          targets.each do |target, target_params|
+          targets.each_key do |target|
             process_target.call(target)
           end
         ensure
@@ -404,7 +406,8 @@ module Rscons
     #
     # @return [void]
     def add_target(target, builder, sources, vars, args)
-      @targets[target] = {
+      @targets[target] ||= []
+      @targets[target] << {
         builder: builder,
         sources: sources,
         vars: vars,
@@ -506,7 +509,11 @@ module Rscons
     #
     # @return [String] The expanded path.
     def expand_path(path)
-      path.sub(%r{^\^(?=[\\/])}, @build_root)
+      if Rscons.phony_target?(path)
+        path
+      else
+        path.sub(%r{^\^(?=[\\/])}, @build_root)
+      end
     end
 
     # Execute a command using the system shell.
@@ -662,8 +669,10 @@ module Rscons
 
     # Print the Environment's construction variables for debugging.
     def dump
-      @varset.to_h.sort.each do |var, val|
+      varset_hash = @varset.to_h
-        puts "#{var} => #{val.inspect}"
+      varset_hash.keys.sort_by(&:to_s).each do |var|
+        var_str = var.is_a?(Symbol) ? var.inspect : var
+        puts "#{var_str} => #{varset_hash[var].inspect}"
       end
     end
 
@@ -677,14 +686,16 @@ module Rscons
     #
     # @return [void]
     def expand_paths!
-      @targets = @targets.reduce({}) do |result, (target, target_params)|
+      @targets = @targets.reduce({}) do |result, (target, target_params_list)|
-        sources = target_params[:sources].map do |source|
-          source = expand_path(source) if @build_root
-          expand_varref(source)
-        end
         target = expand_path(target) if @build_root
         target = expand_varref(target)
-        result[target] = target_params.merge(sources: sources)
+        result[target] = target_params_list.map do |target_params|
+          sources = target_params[:sources].map do |source|
+            source = expand_path(source) if @build_root
+            expand_varref(source)
+          end.flatten
+          target_params.merge(sources: sources)
+        end
         result
       end
     end
@@ -694,7 +705,8 @@ module Rscons
     # 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.
+    # @param target [String, nil]
+    #   Name of the target to gather dependencies for, nil for any/all.
     #
     # @return [Array<String>] Paths of dependency files.
     def self.parse_makefile_deps(mf_fname, target)
@@ -707,7 +719,7 @@ module Rscons
           buildup += ' ' + line
           if buildup =~ /^(.*): (.*)$/
             mf_target, mf_deps = $1.strip, $2
-            if mf_target == target
+            if target.nil? or mf_target == target
               deps += mf_deps.split(' ').map(&:strip)
             end
           end

lib/rscons/varset.rb

@@ -116,6 +116,8 @@ module Rscons
         expand_varref(varref[*lambda_args], lambda_args)
       elsif varref.nil?
         nil
+      elsif varref.is_a?(Symbol)
+        varref
       else
         raise "Unknown varref type: #{varref.class} (#{varref.inspect})"
       end

lib/rscons/version.rb

@@ -1,4 +1,4 @@
 module Rscons
   # gem version
-  VERSION = "1.8.0"
+  VERSION = "1.9.2"
 end

spec/build_tests_spec.rb

@@ -725,11 +725,245 @@ EOF
     test_dir("simple")
     env = Rscons::Environment.new do |env|
       env["CFLAGS"] += %w[-O2 -fomit-frame-pointer]
+      env[:foo] = :bar
     end
     env.dump
     result = lines
+    expect(result.include?(%{:foo => :bar})).to be_truthy
     expect(result.include?(%{CFLAGS => ["-O2", "-fomit-frame-pointer"]})).to be_truthy
     expect(result.include?(%{CPPPATH => []})).to be_truthy
   end
 
+  it "considers deep dependencies when deciding whether to rerun Preprocess builder" do
+    test_dir("preprocess")
+    env = Rscons::Environment.new do |env|
+      env.Preprocess("pp", "foo.h")
+    end
+    expect(File.read("pp")).to match(%r{xyz42abc}m)
+    expect(lines).to eq(["Preprocess pp"])
+    env.Preprocess("pp", "foo.h")
+    env.process
+    expect(lines).to eq([])
+    File.open("bar.h", "w") do |fh|
+      fh.puts "#define BAR abc88xyz"
+    end
+    $ttt = true
+    env.Preprocess("pp", "foo.h")
+    env.process
+    expect(lines).to eq(["Preprocess pp"])
+    expect(File.read("pp")).to match(%r{abc88xyz}m)
+  end
+
+  it "allows construction variable references which expand to arrays in sources of a build target" do
+    test_dir("simple")
+    Rscons::Environment.new do |env|
+      env["sources"] = Dir["*.c"]
+      env.Program("simple", "${sources}")
+    end
+    expect(File.exists?("simple.o")).to be_truthy
+    expect(`./simple`).to eq "This is a simple C program\n"
+  end
+
+  it "supports registering multiple build targets with the same target path" do
+    test_dir("build_dir")
+    Rscons::Environment.new do |env|
+      env["CPPPATH"] << "src/two"
+      env.Object("one.o", "src/one/one.c")
+      env.Object("one.o", "src/two/two.c")
+    end
+    expect(File.exists?("one.o")).to be_truthy
+    expect(lines).to eq([
+      "CC one.o",
+      "CC one.o",
+    ])
+  end
+
+  it "expands target and source paths when builders are registered in build hooks" do
+    test_dir("build_dir")
+    Rscons::Environment.new do |env|
+      env["CPPPATH"] << "src/two"
+      env.Object("one.o", "src/one/one.c")
+      env.add_post_build_hook do |build_op|
+        if build_op[:target] == "one.o"
+          env["MODULE"] = "two"
+          env.Object("${MODULE}.o", "src/${MODULE}/${MODULE}.c")
+        end
+      end
+    end
+    expect(File.exists?("one.o")).to be_truthy
+    expect(File.exists?("two.o")).to be_truthy
+    expect(lines).to eq([
+      "CC one.o",
+      "CC two.o",
+    ])
+  end
+
+  context "Directory builder" do
+    it "creates the requested directory" do
+      test_dir("simple")
+      Rscons::Environment.new do |env|
+        env.Directory("teh_dir")
+      end
+      expect(File.directory?("teh_dir")).to be_truthy
+      expect(lines).to eq(["Directory teh_dir"])
+    end
+
+    it "succeeds when the requested directory already exists" do
+      test_dir("simple")
+      FileUtils.mkdir("teh_dir")
+      Rscons::Environment.new do |env|
+        env.Directory("teh_dir")
+      end
+      expect(File.directory?("teh_dir")).to be_truthy
+      expect(lines).to eq([])
+    end
+
+    it "fails when the target path is a file" do
+      test_dir("simple")
+      FileUtils.touch("teh_dir")
+      expect do
+        Rscons::Environment.new do |env|
+          env.Directory("teh_dir")
+        end
+      end.to raise_error /Failed to build teh_dir/
+      expect(lines).to eq([
+        "Error: `teh_dir' already exists and is not a directory",
+      ])
+    end
+  end
+
+  context "Install buildler" do
+    let(:base_env) do
+      test_dir("build_dir")
+      Rscons::Environment.new do |env|
+        env["CPPPATH"] = Dir["src/**/"]
+        env["sources"] = Dir["src/**/*.c"]
+        env.Program("simple.exe", "${sources}")
+      end
+    end
+
+    it "copies a file to the target file name" do
+      env = base_env.clone do |env|
+        lines
+        env.Install("inst.exe", "simple.exe")
+      end
+      expect(lines).to eq(["Install inst.exe"])
+      env.Install("inst.exe", "simple.exe")
+      env.process
+      expect(lines).to eq([])
+      expect(File.exists?("inst.exe")).to be_truthy
+      expect(File.read("inst.exe", mode: "rb")).to eq(File.read("simple.exe", mode: "rb"))
+      FileUtils.rm("inst.exe")
+      env.Install("inst.exe", "simple.exe")
+      env.process
+      expect(lines).to eq(["Install inst.exe"])
+    end
+
+    it "operates the same as a Copy builder" do
+      env = base_env.clone do |env|
+        lines
+        env.Copy("inst.exe", "simple.exe")
+      end
+      expect(lines).to eq(["Copy inst.exe"])
+      env.Copy("inst.exe", "simple.exe")
+      env.process
+      expect(lines).to eq([])
+      expect(File.exists?("inst.exe")).to be_truthy
+      expect(File.read("inst.exe", mode: "rb")).to eq(File.read("simple.exe", mode: "rb"))
+      FileUtils.rm("inst.exe")
+      env.Copy("inst.exe", "simple.exe")
+      env.process
+      expect(lines).to eq(["Copy inst.exe"])
+    end
+
+    it "copies a file to the target directory name" do
+      env = base_env.clone do |env|
+        lines
+        env.Directory("inst")
+        env.Install("inst", "simple.exe")
+      end
+      expect(lines).to eq([
+        "Directory inst",
+        "Install inst",
+      ])
+      env.Install("inst", "simple.exe")
+      env.process
+      expect(lines).to eq([])
+      expect(File.exists?("inst/simple.exe")).to be_truthy
+      expect(File.read("inst/simple.exe", mode: "rb")).to eq(File.read("simple.exe", mode: "rb"))
+    end
+
+    it "copies a directory to the non-existent target directory name" do
+      env = base_env.clone do |env|
+        lines
+        env.Install("dist/src", "src")
+      end
+      expect(lines).to eq(["Install dist/src"])
+      env.Install("dist/src", "src")
+      env.process
+      expect(lines).to eq([])
+      %w[src/one/one.c src/two/two.c src/two/two.h].each do |f|
+        expect(File.exists?("dist/#{f}")).to be_truthy
+        expect(File.read("dist/#{f}", mode: "rb")).to eq(File.read(f, mode: "rb"))
+      end
+    end
+
+    it "copies a directory to the existent target directory name" do
+      env = base_env.clone do |env|
+        lines
+        env.Directory("dist/src")
+        env.Install("dist/src", "src")
+      end
+      expect(lines).to eq([
+        "Directory dist/src",
+        "Install dist/src",
+      ])
+      env.Install("dist/src", "src")
+      env.process
+      expect(lines).to eq([])
+      %w[src/one/one.c src/two/two.c src/two/two.h].each do |f|
+        expect(File.exists?("dist/#{f}")).to be_truthy
+        expect(File.read("dist/#{f}", mode: "rb")).to eq(File.read(f, mode: "rb"))
+      end
+      FileUtils.rm("dist/src/two/two.c")
+      env.Install("dist/src", "src")
+      env.process
+      expect(lines).to eq(["Install dist/src"])
+    end
+  end
+
+  context "phony targets" do
+    [false, true].each do |with_build_root|
+      it "allows specifying a Symbol as a target name and reruns the builder if the sources or command have changed" do
+        test_dir("simple")
+        env = Rscons::Environment.new do |env|
+          env.build_root = "bld" if with_build_root
+          env.add_builder(:Checker) do |target, sources, cache, env, vars|
+            unless cache.up_to_date?(target, :Checker, sources, env)
+              puts "Checker #{sources.first}" if env.echo != :off
+              cache.register_build(target, :Checker, sources, env)
+            end
+            target
+          end
+          env.Program("simple.exe", "simple.c")
+          env.Checker(:checker, "simple.exe")
+        end
+        expect(lines).to eq(["CC #{with_build_root ? 'bld/' : ''}simple.o", "LD simple.exe", "Checker simple.exe"])
+
+        env.clone do |env|
+          env.Checker(:checker, "simple.exe")
+        end
+        expect(lines).to eq([])
+
+        File.open("simple.exe", "w") do |fh|
+          fh.puts "Changed simple.exe"
+        end
+        env.clone do |env|
+          env.Checker(:checker, "simple.exe")
+        end
+        expect(lines).to eq(["Checker simple.exe"])
+      end
+    end
+  end
+
 end

spec/rscons/builders/command_spec.rb

@@ -1,16 +1,18 @@
 module Rscons
   module Builders
     describe Command do
+
       let(:command) { ['pandoc', '-fmarkdown', '-thtml', '-o${_TARGET}', '${_SOURCES}'] }
       let(:env) {Environment.new}
       subject {Command.new}
 
-
       it "invokes the command to build the target" do
         expected_cmd = ['pandoc', '-fmarkdown', '-thtml', '-ofoo.html', 'foo.md']
-        expect(subject).to receive(:standard_build).with("CMD foo.html", "foo.html", expected_cmd, ["foo.md"], env, :cache)
+        expect(subject).to receive(:standard_build).with("PANDOC foo.html", "foo.html", expected_cmd, ["foo.md"], env, :cache)
-        subject.run("foo.html", ["foo.md"], :cache, env, {'CMD' => command})
+        subject.run("foo.html", ["foo.md"], :cache, env,
+                    "CMD" => command, "CMD_DESC" => "PANDOC")
       end
+
     end
   end
 end

spec/rscons/builders/preprocess_spec.rb

@@ -1,18 +1,48 @@
 module Rscons
   module Builders
     describe Preprocess do
+
       let(:env) {Environment.new}
       subject {Preprocess.new}
 
       it "supports overriding CC construction variable" do
-        expect(subject).to receive(:standard_build).with("Preprocess module.pp", "module.pp", ["my_cpp", "-E", "-o", "module.pp", "module.c"], ["module.c"], env, :cache)
+        cache = double(Cache)
-        subject.run("module.pp", ["module.c"], :cache, env, "CC" => "my_cpp")
+        command = %w[my_cpp -E -MMD -MF module.mf -o module.pp module.c]
+        expect(cache).to receive(:up_to_date?).with("module.pp", command, %w[module.c], env).and_return(false)
+        expect(cache).to receive(:mkdir_p).with(".")
+        expect(env).to receive(:execute).with("Preprocess module.pp", command).and_return(true)
+        expect(File).to receive(:exists?).with("module.mf").and_return(true)
+        expect(Environment).to receive(:parse_makefile_deps).with("module.mf", nil).and_return(%w[module.c one.h two.h])
+        expect(FileUtils).to receive(:rm_f).with("module.mf")
+        expect(cache).to receive(:register_build).with("module.pp", command, %w[module.c one.h two.h], env)
+
+        expect(subject.run("module.pp", ["module.c"], cache, env, "CC" => "my_cpp")).to eq("module.pp")
       end
 
       it "supports overriding CPP_CMD construction variable" do
-        expect(subject).to receive(:standard_build).with("Preprocess module.pp", "module.pp", ["my_cpp", "module.c"], ["module.c"], env, :cache)
+        cache = double(Cache)
-        subject.run("module.pp", ["module.c"], :cache, env, "CPP_CMD" => ["my_cpp", "${_SOURCES}"])
+        command = %w[my_cpp module.c]
+        expect(cache).to receive(:up_to_date?).with("module.pp", command, %w[module.c], env).and_return(false)
+        expect(cache).to receive(:mkdir_p).with(".")
+        expect(env).to receive(:execute).with("Preprocess module.pp", command).and_return(true)
+        expect(File).to receive(:exists?).with("module.mf").and_return(true)
+        expect(Environment).to receive(:parse_makefile_deps).with("module.mf", nil).and_return(%w[module.c one.h two.h])
+        expect(FileUtils).to receive(:rm_f).with("module.mf")
+        expect(cache).to receive(:register_build).with("module.pp", command, %w[module.c one.h two.h], env)
+
+        expect(subject.run("module.pp", ["module.c"], cache, env, "CPP_CMD" => ["my_cpp", "${_SOURCES}"])).to eq("module.pp")
       end
+
+      it "returns false if executing the preprocessor fails" do
+        cache = double(Cache)
+        command = %w[gcc -E -MMD -MF module.mf -o module.pp module.c]
+        expect(cache).to receive(:up_to_date?).with("module.pp", command, %w[module.c], env).and_return(false)
+        expect(cache).to receive(:mkdir_p).with(".")
+        expect(env).to receive(:execute).with("Preprocess module.pp", command).and_return(false)
+
+        expect(subject.run("module.pp", ["module.c"], cache, env, {})).to eq(false)
+      end
+
     end
   end
 end

spec/rscons/environment_spec.rb

@@ -305,10 +305,10 @@ module Rscons
         env.Object("target.o", ["src1.c", "src2.c"], var: "val")
         target = env.instance_variable_get(:@targets)["target.o"]
         expect(target).to_not be_nil
-        expect(target[:builder].is_a?(Builder)).to be_truthy
+        expect(target[0][:builder].is_a?(Builder)).to be_truthy
-        expect(target[:sources]).to eq ["src1.c", "src2.c"]
+        expect(target[0][:sources]).to eq ["src1.c", "src2.c"]
-        expect(target[:vars]).to eq({var: "val"})
+        expect(target[0][:vars]).to eq({var: "val"})
-        expect(target[:args]).to eq []
+        expect(target[0][:args]).to eq []
       end
 
       it "raises an error when vars is not a Hash" do

spec/rscons_spec.rb

@@ -24,13 +24,23 @@ describe Rscons do
     end
   end
 
+  describe ".set_suffix" do
+    it "changes the suffix to the new one" do
+      expect(Rscons.set_suffix("foo.c", ".h")).to eq("foo.h")
+    end
+
+    it "appends a suffix if the given file name does not have one" do
+      expect(Rscons.set_suffix("bazz", ".d")).to eq("bazz.d")
+    end
+  end
+
   describe ".get_system_shell" do
     before(:each) do
-      Rscons.class_variable_set(:@@shell, nil)
+      Rscons.instance_variable_set(:@shell, nil)
     end
 
     after(:each) do
-      Rscons.class_variable_set(:@@shell, nil)
+      Rscons.instance_variable_set(:@shell, nil)
     end
 
     it "uses the SHELL environment variable if it tests successfully" do
@@ -70,11 +80,11 @@ describe Rscons do
   context "command executer" do
     describe ".command_executer" do
       before(:each) do
-        Rscons.class_variable_set(:@@command_executer, nil)
+        Rscons.instance_variable_set(:@command_executer, nil)
       end
 
       after(:each) do
-        Rscons.class_variable_set(:@@command_executer, nil)
+        Rscons.instance_variable_set(:@command_executer, nil)
       end
 
       it "returns ['env'] if mingw platform in MSYS and 'env' works" do
@@ -105,10 +115,10 @@ describe Rscons do
     end
 
     describe ".command_executer=" do
-      it "overrides the value of @@command_executer" do
+      it "overrides the value of @command_executer" do
-        Rscons.class_variable_set(:@@command_executer, ["env"])
+        Rscons.instance_variable_set(:@command_executer, ["env"])
         Rscons.command_executer = []
-        expect(Rscons.class_variable_get(:@@command_executer)).to eq([])
+        expect(Rscons.instance_variable_get(:@command_executer)).to eq([])
       end
     end
   end