update build_tests_spec to invoke rscons in a subprocess for each test

build_tests/simple/Rsconsfile

@@ -0,0 +1,3 @@
+Rscons::Environment.new do |env|
+  env.Program('simple', Dir['*.c'])
+end

build_tests/simple/build_root_builder_no_sources.rb

@@ -0,0 +1,10 @@
+class TestBuilder < Rscons::Builder
+  def run(target, sources, cache, env, vars)
+    target
+  end
+end
+Rscons::Environment.new do |env|
+  env.build_root = "build"
+  env.add_builder(TestBuilder.new)
+  env.TestBuilder("file")
+end

build_tests/simple/cache_successful_builds_when_one_fails.rb

@@ -0,0 +1,4 @@
+Rscons::Environment.new do |env|
+  env.Object("simple.o", "simple.c")
+  env.Object("two.o", "two.c")
+end

build_tests/simple/clear_targets.rb

@@ -0,0 +1,4 @@
+Rscons::Environment.new do |env|
+  env.Program("simple.exe", "simple.c")
+  env.clear_targets
+end

build_tests/simple/command.rb

@@ -0,0 +1,4 @@
+Rscons::Environment.new(echo: :command) do |env|
+  env["LD"] = "gcc"
+  env.Program('simple.exe', Dir['*.c'])
+end

build_tests/simple/cvar_array.rb

@@ -0,0 +1,4 @@
+Rscons::Environment.new do |env|
+  env["sources"] = Dir["*.c"].sort
+  env.Program("simple.exe", "${sources}")
+end

build_tests/simple/directory.rb

@@ -0,0 +1,3 @@
+Rscons::Environment.new do |env|
+  env.Directory("teh_dir")
+end

build_tests/simple/disassemble.rb

@@ -0,0 +1,4 @@
+Rscons::Environment.new do |env|
+  env.Object("simple.o", "simple.c")
+  env.Disassemble("simple.txt", "simple.o")
+end

build_tests/simple/dump.rb

@@ -0,0 +1,5 @@
+env = Rscons::Environment.new do |env|
+  env["CFLAGS"] += %w[-O2 -fomit-frame-pointer]
+  env[:foo] = :bar
+end
+env.dump

build_tests/simple/link_flag_change.rb

@@ -0,0 +1,5 @@
+Rscons::Environment.new(echo: :command) do |env|
+  env["LD"] = "gcc"
+  env["LIBPATH"] += ["libdir"]
+  env.Program('simple.exe', Dir['*.c'])
+end

build_tests/simple/phony_target.rb

@@ -0,0 +1,12 @@
+Rscons::Environment.new do |env|
+  env.build_root = "build"
+  env.add_builder(:Checker) do |target, sources, cache, env, vars|
+    unless cache.up_to_date?(target, :Checker, sources, env)
+      puts "Checker #{sources.first}" if env.echo != :off
+      cache.register_build(target, :Checker, sources, env)
+    end
+    target
+  end
+  env.Program("simple.exe", "simple.c")
+  env.Checker(:checker, "simple.exe")
+end

build_tests/simple/preprocess.rb

@@ -0,0 +1,4 @@
+Rscons::Environment.new do |env|
+  env.Preprocess("simplepp.c", "simple.c")
+  env.Program("simple.exe", "simplepp.c")
+end

build_tests/simple/register_target_in_build_hook.rb

@@ -0,0 +1,8 @@
+Rscons::Environment.new do |env|
+  env.Program("simple.exe", Dir["*.c"])
+  env.add_build_hook do |build_op|
+    if build_op[:target].end_with?(".o")
+      env.Disassemble("#{build_op[:target]}.txt", build_op[:target])
+    end
+  end
+end

build_tests/simple/user_dependencies.rb

@@ -0,0 +1,4 @@
+Rscons::Environment.new do |env|
+  program = env.Program("simple.exe", Dir["*.c"])
+  env.depends(program, "program.ld")
+end