distinguish object files built from multiple sources with the same base name but different extensions - close #113

build_tests/typical/build_hooks.rb

@@ -2,9 +2,9 @@ build do
   Environment.new(echo: :command) do |env|
     env.append('CPPPATH' => glob('src/**/*/'))
     env.add_build_hook do |builder|
-      if File.basename(builder.target) == "one.o"
+      if File.basename(builder.sources.first) == "one.c"
         builder.vars["CFLAGS"] << "-O1"
-      elsif File.basename(builder.target) == "two.o"
+      elsif File.basename(builder.sources.first) == "two.c"
         builder.vars["CFLAGS"] << "-O2"
       end
     end