Environment: add #parse_flags, #parse_flags!, and #merge_flags

spec/rscons/environment_spec.rb

@@ -379,6 +379,60 @@ module Rscons
       end
     end
 
+    describe "#parse_flags" do
+      it "executes the shell command and parses the returned flags when the input argument begins with !" do
+        env = Environment.new
+        env["CFLAGS"] = ["-g"]
+        env.should_receive(:shell).with("my_command").and_return(%[-arch my_arch -Done=two -include ii -isysroot sr -Iincdir -Llibdir -lmy_lib -mno-cygwin -mwindows -pthread -std=c99 -Wa,'asm,args 1 2' -Wl,linker,"args 1 2" -Wp,cpp,args,1,2 -arbitrary +other_arbitrary some_lib /a/b/c/lib])
+        rv = env.parse_flags("!my_command")
+        expect(rv).to eq({
+          "CCFLAGS" => %w[-arch my_arch -include ii -isysroot sr -mno-cygwin -pthread -arbitrary +other_arbitrary],
+          "LDFLAGS" => %w[-arch my_arch -isysroot sr -mno-cygwin -mwindows -pthread] + ["linker", "args 1 2"] + %w[+other_arbitrary],
+          "CPPPATH" => %w[incdir],
+          "LIBS" => %w[my_lib some_lib /a/b/c/lib],
+          "LIBPATH" => %w[libdir],
+          "CPPDEFINES" => %w[one=two],
+          "CFLAGS" => %w[-std=c99],
+          "ASFLAGS" => ["asm", "args 1 2"],
+          "CPPFLAGS" => %w[cpp args 1 2],
+        })
+        expect(env["CFLAGS"]).to eq(["-g"])
+        expect(env["ASFLAGS"]).to eq([])
+        env.merge_flags(rv)
+        expect(env["CFLAGS"]).to eq(["-g", "-std=c99"])
+        expect(env["ASFLAGS"]).to eq(["asm", "args 1 2"])
+      end
+    end
+
+    describe "#parse_flags!" do
+      it "parses the given build flags and merges them into the Environment" do
+        env = Environment.new
+        env["CFLAGS"] = ["-g"]
+        rv = env.parse_flags!("-I incdir -D my_define -L /a/libdir -l /some/lib")
+        expect(rv).to eq({
+          "CPPPATH" => %w[incdir],
+          "LIBS" => %w[/some/lib],
+          "LIBPATH" => %w[/a/libdir],
+          "CPPDEFINES" => %w[my_define],
+        })
+        expect(env["CPPPATH"]).to eq(%w[incdir])
+        expect(env["LIBS"]).to eq(%w[/some/lib])
+        expect(env["LIBPATH"]).to eq(%w[/a/libdir])
+        expect(env["CPPDEFINES"]).to eq(%w[my_define])
+      end
+    end
+
+    describe "#merge_flags" do
+      it "appends array contents and replaces other variable values" do
+        env = Environment.new
+        env["CPPPATH"] = ["incdir"]
+        env["CSUFFIX"] = ".x"
+        env.merge_flags("CPPPATH" => ["a"], "CSUFFIX" => ".c")
+        expect(env["CPPPATH"]).to eq(%w[incdir a])
+        expect(env["CSUFFIX"]).to eq(".c")
+      end
+    end
+
     describe ".parse_makefile_deps" do
       it 'handles dependencies on one line' do
         File.should_receive(:read).with('makefile').and_return(<<EOS)