improve debuggability of cache.up_to_date? - close #46

build_tests/simple/cache_debugging.rb

@@ -0,0 +1,34 @@
+class DebugBuilder < Rscons::Builder
+  def run(options)
+    target, sources, cache, env, vars = options.values_at(:target, :sources, :cache, :env, :vars)
+    command = %W[gcc -c -o #{target} #{sources.first}]
+    if ENV["command_change"]
+      command += %w[-Wall]
+    end
+    if ENV["new_dep"]
+      sources += ["extra"]
+    end
+    if ENV["strict_deps1"]
+      sources += ["extra"]
+      strict_deps = true
+    end
+    if ENV["strict_deps2"]
+      sources = ["extra"] + sources
+      strict_deps = true
+    end
+    unless cache.up_to_date?(target, command, sources, env, debug: true, strict_deps: strict_deps)
+      desc = "#{self.class.name} #{target}"
+      return false unless env.execute(desc, command)
+      cache.register_build(target, command, sources, env)
+    end
+    target
+  end
+end
+
+Rscons::Environment.new do |env|
+  env.add_builder(DebugBuilder.new)
+  if ENV["new_user_dep"]
+    env.depends("foo.o", "new_dep")
+  end
+  env.DebugBuilder("foo.o", "simple.c")
+end