add verbose CLI option to set Environment default echo mode - close #70

lib/rscons/application.rb

@@ -11,6 +11,10 @@ module Rscons
     #   The number of threads to use when scheduling subprocesses.
     attr_accessor :n_threads
 
+    # @return [Boolean]
+    #   Whether to run verbosely.
+    attr_accessor :verbose
+
     # @return [VarSet]
     #   Access any variables set on the rscons command-line.
     attr_reader :vars

lib/rscons/cli.rb

@@ -8,6 +8,7 @@ Global options:
   --version                   Show rscons version and exit
   -h, --help                  Show rscons help and exit
   -r COLOR, --color=COLOR     Set color mode (off, auto, force)
+  -v, --verbose               Run verbosely
 
 Operations:
   configure                   Configure the project
@@ -78,6 +79,10 @@ module Rscons
             end
           end
 
+          opts.on("-v", "--verbose") do
+            Rscons.application.verbose = true
+          end
+
           opts.on("--version") do
             puts "Rscons version #{Rscons::VERSION}"
             exit 0

lib/rscons/environment.rb

@@ -81,7 +81,14 @@ module Rscons
           add_builder(builder_class.new)
         end
       end
-      @echo = options[:echo] || :short
+      @echo =
+        if options[:echo]
+          options[:echo]
+        elsif Rscons.application.verbose
+          :command
+        else
+          :short
+        end
       @build_root = "#{Cache.instance.configuration_data["build_dir"]}/e.#{@id}"
 
       if block_given?