support false :use value for configure operations - close #93

build_tests/configure/check_lib_use_false.rb

@@ -0,0 +1,10 @@
+configure do
+  check_lib "m", use: false
+end
+
+build do
+  Environment.new(echo: :command) do |env|
+    env.Copy("test1.c", "simple.c")
+    env.Program("test2.exe", "test1.c")
+  end
+end

lib/rscons/configure_op.rb

@@ -360,15 +360,19 @@ module Rscons
     # @return [Hash]
     #   Configuration Hash for storing vars.
     def store_common(options)
-      usename =
+      if options[:use] == false
-        if options[:use]
+        {}
-          options[:use].to_s
+      else
-        else
+        usename =
-          "_default_"
+          if options[:use]
-        end
+            options[:use].to_s
-      cache = Cache.instance
+          else
-      cache["configuration_data"]["vars"] ||= {}
+            "_default_"
-      cache["configuration_data"]["vars"][usename] ||= {}
+          end
+        cache = Cache.instance
+        cache["configuration_data"]["vars"] ||= {}
+        cache["configuration_data"]["vars"][usename] ||= {}
+      end
     end
 
     # Perform processing common to several configure checks.

spec/build_tests_spec.rb

@@ -1806,6 +1806,15 @@ EOF
         expect(result.stdout).to_not match /gcc.*test1.*-lm/
         expect(result.stdout).to match /gcc.*test2.*-lm/
       end
+
+      it "does not link against the checked library if :use is set to false" do
+        test_dir "configure"
+        result = run_rscons(rsconscript: "check_lib_use_false.rb", op: "build")
+        expect(result.stderr).to eq ""
+        expect(result.status).to eq 0
+        expect(result.stdout).to match /Checking for library 'm'... found/
+        expect(result.stdout).to_not match /-lm/
+      end
     end
 
     context "check_program" do