Delay test code build until `rake test`

With this change, the test code will not be built unless `rake test` is
run, so there will be almost no side effects even if `enable_test` is
always set (but, gems specified by `add_test_dependency` are included
in `libmruby.a`).

Also added are `test: build` task, which only builds the test code
(including the main code), and `test: run` task, which only runs tests
independent of build. Therefore, the idiom for building in parallel and
not running tests in parallel is `rake -m test:build && rake test:run`.

10 files changed, 138 insertions, 106 deletions

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 5e530ae5e..135e39ca7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -25,7 +25,7 @@ jobs:
       - name: Compiler version
         run: ${{ env.CC }} --version
       - name: Build and test
-        run: rake -m && rake test
+        run: rake -m test:build && rake test:run
 
   Ubuntu-1804-gcc:
     needs: Check-Skip
@@ -40,7 +40,7 @@ jobs:
       - name: Compiler version
         run: ${{ env.CC }} --version
       - name: Build and test
-        run: rake -m && rake test
+        run: rake -m test:build && rake test:run
 
   Ubuntu-1804-clang:
     needs: Check-Skip
@@ -55,7 +55,7 @@ jobs:
       - name: Compiler version
         run: ${{ env.CC }} --version
       - name: Build and test
-        run: rake -m && rake test
+        run: rake -m test:build && rake test:run
 
   macOS:
     needs: Check-Skip
@@ -70,7 +70,7 @@ jobs:
       - name: Compiler version
         run: ${{ env.CC }} --version
       - name: Build and test
-        run: rake -m && rake test
+        run: rake -m test:build && rake test:run
 
   Windows-MinGW:
     needs: Check-Skip
@@ -85,9 +85,7 @@ jobs:
       - name: Compiler version
         run: ${{ env.CC }} --version
       - name: Build and test
-        # If build and test are separated like `rake && rake test`, somehow
-        # it will be fully built even at `rake test`, so it is not separated.
-        run: rake test
+        run: rake -m test:build && rake test:run
 
   Windows-Cygwin:
     needs: Check-Skip
@@ -130,7 +128,7 @@ jobs:
         run: ${{ env.CC }} --version
       - name: Build and test
         shell: cmd
-        run: ruby /usr/bin/rake -m && ruby /usr/bin/rake test
+        run: ruby /usr/bin/rake -m test:build && ruby /usr/bin/rake test:run
       - name: Set PATH for cache archiving (tar)
         # set Windows path so that Cygwin tar is not used for cache archiving
         run: echo '::set-env name=PATH::C:\windows\System32'
@@ -148,4 +146,4 @@ jobs:
         shell: cmd
         run: |
           call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
-          rake -m && rake test
+          rake -m test:build && rake test:run
diff --git a/.travis.yml b/.travis.yml
index 1e09654be..c47a54494 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,4 +8,4 @@ env:
   - MRUBY_CONFIG=ci/gcc-clang
 
 script:
-  - rake -m && rake test
+  - rake -m test:build && rake test:run
diff --git a/Rakefile b/Rakefile
index 813486bf6..731977aa8 100644
--- a/Rakefile
+++ b/Rakefile
@@ -29,6 +29,7 @@ load "#{MRUBY_ROOT}/tasks/mrbgems.rake"
 load "#{MRUBY_ROOT}/tasks/libmruby.rake"
 load "#{MRUBY_ROOT}/tasks/bin.rake"
 load "#{MRUBY_ROOT}/tasks/presym.rake"
+load "#{MRUBY_ROOT}/tasks/test.rake"
 load "#{MRUBY_ROOT}/tasks/benchmark.rake"
 load "#{MRUBY_ROOT}/tasks/gitlab.rake"
 load "#{MRUBY_ROOT}/tasks/doc.rake"
@@ -51,37 +52,17 @@ end
 
 task :build => MRuby.targets.flat_map{|_, build| build.products}
 
-desc "run all mruby tests"
-task :test
-MRuby.each_target do
-  if test_enabled?
-    t = :"test_#{self.name}"
-    task t => ["all"] do
-      run_test
-    end
-    task :test => t
-  end
-
-  if bintest_enabled?
-    t = :"bintest_#{self.name}"
-    task t => ["all"] do
-      run_bintest
-    end
-    task :test => t
-  end
-end
-
 desc "clean all built and in-repo installed artifacts"
 task :clean do
   MRuby.each_target do |build|
-    rm_rf build.products
     rm_rf build.build_dir
+    rm_f build.products
   end
   puts "Cleaned up target build folder"
 end
 
 desc "clean everything!"
-task :deep_clean => ["clean", "clean_doc"] do
+task :deep_clean => %w[clean doc:clean] do
   MRuby.each_target do |build|
     rm_rf build.gem_clone_dir
   end
diff --git a/appveyor.yml b/appveyor.yml
index 227d7898e..9803bfa8d 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -41,5 +41,5 @@ init:
 
 build_script:
   - set MRUBY_CONFIG=ci/msvc
-  - rake -m
-  - rake test
+  - rake -m test:build
+  - rake test:run
diff --git a/lib/mruby/build.rb b/lib/mruby/build.rb
index 2819ad594..ca2b28457 100644
--- a/lib/mruby/build.rb
+++ b/lib/mruby/build.rb
@@ -100,7 +100,7 @@ module MRuby
         @cc = Command::Compiler.new(self, %w(.c), label: "CC")
         @cxx = Command::Compiler.new(self, %w(.cc .cxx .cpp), label: "CXX")
         @objc = Command::Compiler.new(self, %w(.m), label: "OBJC")
-        @asm = Command::Compiler.new(self, %w(.S .asm), label: "ASM")
+        @asm = Command::Compiler.new(self, %w(.S .asm .s), label: "ASM")
         @linker = Command::Linker.new(self)
         @archiver = Command::Archiver.new(self)
         @yacc = Command::Yacc.new(self)
@@ -140,7 +140,6 @@ module MRuby
         end
       end
       current.presym = Presym.new(current) if current.presym_enabled?
-      current.build_mrbtest if current.test_enabled?
     end
 
     def libmruby_enabled?
@@ -303,15 +302,12 @@ EOS
     def enable_test
       @enable_test = true
     end
+    alias build_mrbtest enable_test
 
     def test_enabled?
       @enable_test
     end
 
-    def build_mrbtest
-      gem :core => 'mruby-test' unless @gems['mruby-test']
-    end
-
     def build_mrbc_exec
       gem :core => 'mruby-bin-mrbc' unless @gems['mruby-bin-mrbc']
     end
@@ -363,6 +359,19 @@ EOS
       end
     end
 
+    def define_installer(src)
+      dst = "#{self.class.install_dir}/#{File.basename(src)}"
+      file dst => src do
+        install_D src, dst
+      end
+      dst
+    end
+
+    def define_installer_if_needed(bin)
+      exe = exefile("#{build_dir}/bin/#{bin}")
+      host? ? define_installer(exe) : exe
+    end
+
     def filename(name)
       if name.is_a?(Array)
         name.flatten.map { |n| filename(n) }
diff --git a/lib/mruby/gem.rb b/lib/mruby/gem.rb
index 4e918745f..f967bcb35 100644
--- a/lib/mruby/gem.rb
+++ b/lib/mruby/gem.rb
@@ -25,8 +25,8 @@ module MRuby
       alias :author= :authors=
 
       attr_accessor :rbfiles, :objs
-      attr_accessor :test_objs, :test_rbfiles, :test_args
-      attr_accessor :test_preload
+      attr_writer :test_objs, :test_rbfiles
+      attr_accessor :test_args, :test_preload
 
       attr_accessor :bins
 
@@ -58,15 +58,8 @@ module MRuby
         @linker.run_attrs.each(&:clear)
 
         @rbfiles = Dir.glob("#{@dir}/mrblib/**/*.rb").sort
-        @objs = Dir.glob("#{@dir}/src/*.{c,cpp,cxx,cc,m,asm,s,S}").map do |f|
-          objfile(f.relative_path_from(@dir).to_s.pathmap("#{build_dir}/%X"))
-        end
+        @objs = srcs_to_objs("src")
 
-        @test_rbfiles = Dir.glob("#{@dir}/test/**/*.rb").sort
-        @test_objs = Dir.glob("#{@dir}/test/*.{c,cpp,cxx,cc,m,asm,s,S}").map do |f|
-          objfile(f.relative_path_from(@dir).to_s.pathmap("#{build_dir}/%X"))
-        end
-        @custom_test_init = !@test_objs.empty?
         @test_preload = nil # 'test/assert.rb'
         @test_args = {}
 
@@ -149,6 +142,14 @@ module MRuby
         "#{build_dir}/gem_test.c"
       end
 
+      def test_objs
+        @test_objs ||= srcs_to_objs("test")
+      end
+
+      def test_rbfiles
+        @test_rbfiles ||= Dir["#{@dir}/test/**/*.rb"].sort!
+      end
+
       def search_package(name, version_query=nil)
         package_query = name
         package_query += " #{version_query}" if version_query
@@ -174,6 +175,13 @@ module MRuby
         end
       end
 
+      def srcs_to_objs(src_dir_from_gem_dir)
+        exts = compilers.flat_map{|c| c.source_exts} * ","
+        Dir["#{@dir}/#{src_dir_from_gem_dir}/*{#{exts}}"].map do |f|
+          objfile(f.relative_path_from(@dir).to_s.pathmap("#{build_dir}/%X"))
+        end
+      end
+
       def define_gem_init_builder
         file "#{build_dir}/gem_init.c" => [build.mrbcfile, __FILE__] + [rbfiles].flatten do |t|
           mkdir_p build_dir
@@ -253,12 +261,8 @@ module MRuby
         f.puts %Q[#include <mruby/hash.h>] unless test_args.empty?
       end
 
-      def test_dependencies
-        [@name]
-      end
-
       def custom_test_init?
-        @custom_test_init
+        !test_objs.empty?
       end
 
       def version_ok?(req_versions)
@@ -487,6 +491,10 @@ module MRuby
           end
         end
       end
+
+      def linker_attrs
+        map{|g| g.linker.run_attrs}.transpose
+      end
     end # List
   end # Gem
 
diff --git a/mrbgems/mruby-test/mrbgem.rake b/mrbgems/mruby-test/mrbgem.rake
index 4a4a7af8f..421108e0b 100644
--- a/mrbgems/mruby-test/mrbgem.rake
+++ b/mrbgems/mruby-test/mrbgem.rake
@@ -3,26 +3,17 @@ MRuby::Gem::Specification.new('mruby-test') do |spec|
   spec.author  = 'mruby developers'
   spec.summary = 'mruby test'
 
-  build.bins << 'mrbtest'
-  spec.add_dependency('mruby-compiler', :core => 'mruby-compiler')
-
   spec.test_rbfiles = Dir.glob("#{MRUBY_ROOT}/test/t/*.rb")
 
   clib = "#{build_dir}/mrbtest.c"
   mlib = clib.ext(exts.object)
   exec = exefile("#{build.build_dir}/bin/mrbtest")
-
-  mrbtest_lib = libfile("#{build_dir}/mrbtest")
-  mrbtest_objs = []
-
-  driver_objs = Dir.glob("#{dir}/*.{c,cpp,cxx,cc,m,asm,s,S}").map do |f|
-    objfile(f.relative_path_from(dir).to_s.pathmap("#{build_dir}/%X"))
-  end
-
   assert_c = "#{build_dir}/assert.c"
   assert_rb = "#{MRUBY_ROOT}/test/assert.rb"
   assert_lib = assert_c.ext(exts.object)
-  mrbtest_objs << assert_lib
+  mrbtest_lib = libfile("#{build_dir}/mrbtest")
+  mrbtest_objs = [assert_lib]
+  driver_objs = srcs_to_objs(".")
 
   file assert_lib => assert_c
   file assert_c => [assert_rb, build.mrbcfile] do |t|
@@ -37,8 +28,9 @@ MRuby::Gem::Specification.new('mruby-test') do |spec|
 
   build.gems.each do |g|
     test_rbobj = g.test_rbireps.ext(exts.object)
-    g.test_objs << test_rbobj
-    dep_list = build.gems.tsort_dependencies(g.test_dependencies, gem_table).select(&:generate_functions)
+    mrbtest_objs.concat(g.test_objs)
+    mrbtest_objs << test_rbobj
+    dep_list = build.gems.tsort_dependencies([g.name], gem_table).select(&:generate_functions)
 
     file test_rbobj => g.test_rbireps
     file g.test_rbireps => [g.test_rbfiles, build.mrbcfile].flatten do |t|
@@ -65,7 +57,7 @@ MRuby::Gem::Specification.new('mruby-test') do |spec|
         g.test_rbfiles.flatten.each_with_index do |rbfile, i|
           g.build.mrbc.run f, rbfile, "gem_test_irep_#{g.funcname}_#{i}", false
         end
-        f.puts %Q[void mrb_#{g.funcname}_gem_test(mrb_state *mrb);] unless g.test_objs.empty?
+        f.puts %Q[void mrb_#{g.funcname}_gem_test(mrb_state *mrb);] if g.custom_test_init?
         dep_list.each do |d|
           f.puts %Q[void GENERATED_TMP_mrb_#{d.funcname}_gem_init(mrb_state *mrb);]
           f.puts %Q[void GENERATED_TMP_mrb_#{d.funcname}_gem_final(mrb_state *mrb);]
@@ -128,23 +120,13 @@ MRuby::Gem::Specification.new('mruby-test') do |spec|
     end
   end
 
-  build.gems.each do |v|
-    mrbtest_objs.concat v.test_objs
-  end
-
   file mrbtest_lib => mrbtest_objs do |t|
     build.archiver.run t.name, t.prerequisites
   end
 
   unless build.build_mrbtest_lib_only?
     file exec => [*driver_objs, mlib, mrbtest_lib, build.libmruby_static] do |t|
-      gem_flags = build.gems.map { |g| g.linker.flags }
-      gem_flags_before_libraries = build.gems.map { |g| g.linker.flags_before_libraries }
-      gem_flags_after_libraries = build.gems.map { |g| g.linker.flags_after_libraries }
-      gem_libraries = build.gems.map { |g| g.linker.libraries }
-      gem_library_paths = build.gems.map { |g| g.linker.library_paths }
-      build.linker.run t.name, t.prerequisites, gem_libraries, gem_library_paths, gem_flags,
-                       gem_flags_before_libraries, gem_flags_after_libraries
+      build.linker.run t.name, t.prerequisites, *build.gems.linker_attrs
     end
   end
 
diff --git a/tasks/bin.rake b/tasks/bin.rake
index afef065a1..bc8820b66 100644
--- a/tasks/bin.rake
+++ b/tasks/bin.rake
@@ -1,35 +1,23 @@
-install_task = ->(src) do
-  dst = "#{MRuby::Build.install_dir}/#{File.basename(src)}"
-  file dst => src do
-    install_D src, dst
-  end
-  dst
-end
-
 MRuby.each_target do |build|
   if build.host? && build.mrbc_build && !build.gems["mruby-bin-mrbc"]
     exe = build.exefile("#{build.mrbc_build.build_dir}/bin/mrbc")
-    build.products << install_task.(exe)
+    build.products << build.define_installer(exe)
   end
 
-  build.bins.each do |bin|
-    exe = build.exefile("#{build.build_dir}/bin/#{bin}")
-    build.products << (build.host? ? install_task.(exe) : exe)
-  end
+  build.bins.each{|bin| build.products << define_installer_if_needed(bin)}
 
-  linker_attrs = build.gems.map{|gem| gem.linker.run_attrs}.transpose
+  linker_attrs = build.gems.linker_attrs
   build.gems.each do |gem|
     gem.bins.each do |bin|
       exe = build.exefile("#{build.build_dir}/bin/#{bin}")
       objs = Dir["#{gem.dir}/tools/#{bin}/*.{c,cpp,cxx,cc}"].map do |f|
         build.objfile(f.pathmap("#{gem.build_dir}/tools/#{bin}/%n"))
       end
-
       file exe => objs.concat(build.libraries) do |t|
         build.linker.run t.name, t.prerequisites, *linker_attrs
       end
 
-      build.products << (build.host? ? install_task.(exe) : exe)
+      build.products << define_installer_if_needed(bin)
     end
   end
 end
diff --git a/tasks/mrbgems.rake b/tasks/mrbgems.rake
index 0a3ae652d..ad98f7356 100644
--- a/tasks/mrbgems.rake
+++ b/tasks/mrbgems.rake
@@ -1,11 +1,12 @@
 MRuby.each_target do
+  active_gems_txt = "#{build_dir}/mrbgems/active_gems.txt"
+
   if enable_gems?
     # set up all gems
     gems.each(&:setup)
     gems.check self
 
     # loader all gems
-    active_gems_txt = "#{build_dir}/mrbgems/active_gems.txt"
     self.libmruby_objs << objfile("#{build_dir}/mrbgems/gem_init")
     file objfile("#{build_dir}/mrbgems/gem_init") => ["#{build_dir}/mrbgems/gem_init.c", "#{build_dir}/LEGAL"]
     file "#{build_dir}/mrbgems/gem_init.c" => [active_gems_txt, MRUBY_CONFIG, __FILE__] do |t|
@@ -50,14 +51,15 @@ MRuby.each_target do
         f.puts %Q[}]
       end
     end
-    file active_gems_txt => :generate_active_gems_txt
-    task :generate_active_gems_txt do |t|
-      def t.timestamp; Time.at(0) end
-      active_gems = gems.sort_by(&:name).inject(""){|s, g| s << "#{g.name}\n"}
-      if !File.exist?(active_gems_txt) || File.read(active_gems_txt) != active_gems
-        mkdir_p File.dirname(active_gems_txt)
-        File.write(active_gems_txt, active_gems)
-      end
+  end
+
+  file active_gems_txt => :generate_active_gems_txt
+  task :generate_active_gems_txt do |t|
+    def t.timestamp; Time.at(0) end
+    active_gems = gems.sort_by(&:name).inject(""){|s, g| s << "#{g.name}\n"}
+    if !File.exist?(active_gems_txt) || File.read(active_gems_txt) != active_gems
+      mkdir_p File.dirname(active_gems_txt)
+      File.write(active_gems_txt, active_gems)
     end
   end
 
diff --git a/tasks/test.rake b/tasks/test.rake
new file mode 100644
index 000000000..80f7670af
--- /dev/null
+++ b/tasks/test.rake
@@ -0,0 +1,64 @@
+desc "build and run all mruby tests"
+task :test => "test:build" do
+  Rake::Task["test:run"].invoke
+end
+
+namespace :test do |test_ns|
+  desc "build and run library tests"
+  task :lib => "build:lib" do
+    test_ns["run:lib"].invoke
+  end
+
+  desc "build and run command binaries tests"
+  task :bin => :all do
+    test_ns["run:bin"].invoke
+  end
+
+  desc "build all mruby tests"
+  task :build => "build:lib"
+
+  namespace :build do
+    desc "build library tests"
+    task :lib
+  end
+
+  desc "run all mruby tests"
+  task :run
+
+  namespace :run do
+    desc "run library tests"
+    task :lib
+
+    desc "run command binaries tests"
+    task :bin
+  end
+end
+
+MRuby.each_target do |build|
+  if build.test_enabled?
+    t = task "test:build:lib:#{build.name}" => :all do
+      gem = build.gem(core: 'mruby-test')
+      gem.setup
+      gem.setup_compilers
+      Rake::Task[build.define_installer_if_needed("mrbtest")].invoke
+    end
+    task "test:build:lib" => t
+
+    t = task "test:run:lib:#{build.name}" do
+      build.run_test
+    end
+    task "test:run" => t
+    task "test:run:lib" => t
+  end
+  if build.bintest_enabled?
+    t = task "test:run:bin:#{build.name}" do
+      build.run_bintest
+    end
+    task "test:run" => t
+    task "test:run:bin" => t
+  end
+end
+
+task :clean do
+  rm_f "#{MRuby::Build.install_dir}/mrbtest"
+end