Move stages into subdirectories

Rakefile

@@ -4,19 +4,18 @@
 # frozen_string_literal: true
 
 require 'open3'
+require 'pathname'
 require 'rake/clean'
 
-STAGES = Dir.glob('boot/stage*.elna')
-  .collect { |stage| File.basename stage, '.elna' }
+STAGES = Dir.glob('boot/stage*')
+  .collect { |stage| File.basename stage }
   .sort { |a, b| a.delete_prefix('stage').to_i <=> b.delete_prefix('stage').to_i }
+  .drop(1) # First assembly stage does not count.
 
 CLEAN.include 'build/boot', 'build/valid'
 
-directory 'build/boot'
-directory 'build/valid'
-
-def compile(input, output)
-  sh ENV.fetch('CC', 'gcc'), '-nostdlib', '-fpie', '-g', '-o', output, input
+def compile(*arguments)
+  sh(ENV.fetch('CC', 'gcc'), '-fpie', '-g', *arguments)
 end
 
 def run(exe)
@@ -26,9 +25,9 @@ end
 task default: :boot
 
 desc 'Final stage'
-task boot: "build/valid/#{STAGES.last}"
-task boot: "build/valid/#{STAGES.last}.s"
-task boot: "boot/#{STAGES.last}.elna" do |t|
+task boot: "build/valid/#{STAGES.last}/cl"
+task boot: "build/valid/#{STAGES.last}/cl.s"
+task boot: "boot/#{STAGES.last}/cl.elna" do |t|
   groupped = t.prerequisites.group_by { |stage| File.extname stage }.transform_values(&:first)
   exe = groupped['']
   expected = groupped['.s']
@@ -81,16 +80,33 @@ task :convert do
   end
 end
 
-rule /^build\/[[:alpha:]]+\/stage[[:digit:]]+$/ => ->(match) {
-  "#{match}.s"
+rule /^build\/[[:alpha:]]+\/stage[[:digit:]]+\/cl$/ => ->(match) {
+  "#{match}.o"
 } do |t|
-  compile(*t.prerequisites, t.name)
+  arguments_path = Pathname.new('boot') + Pathname.new(t.name).dirname.basename + 'linker.arg'
+  if arguments_path.exist?
+    arguments1 = ['--dynamic-linker', '/lib32/ld-linux-riscv32-ilp32d.so.1', '/usr/lib/crt1.o', '/usr/lib/crti.o', '-lc']
+    arguments2 = ['/usr/lib/crtn.o']
+  else
+    arguments1 = arguments2 = []
+  end
+
+  sh(ENV.fetch('LD', 'ld'), '-o', t.name, *arguments1, *t.prerequisites, *arguments2)
+end
+
+rule /^build\/[[:alpha:]]+\/stage[[:digit:]]+\/cl.o$/ => ->(match) {
+  match.ext('.s')
+} do |t|
+  compile('-c', '-o', t.name, *t.prerequisites)
 end
 
 STAGES.each do |stage|
   previous = stage.delete_prefix('stage').to_i.pred
 
-  file "build/valid/#{stage}.s" => ["build/boot/#{stage}", "boot/#{stage}.elna"] do |t|
+  directory "build/valid/#{stage}"
+  directory "build/boot/#{stage}"
+
+  file "build/valid/#{stage}/cl.s" => ["build/boot/#{stage}/cl", "boot/#{stage}/cl.elna", "build/valid/#{stage}"] do |t|
     exe, source = t.prerequisites
 
     cat_arguments = ['cat', source]
@@ -99,7 +115,7 @@ STAGES.each do |stage|
     IO.copy_stream last_stdout, t.name
   end
 
-  file "build/boot/#{stage}.s" => ["build/valid/stage#{previous}", "boot/#{stage}.elna"] do |t|
+  file "build/boot/#{stage}/cl.s" => ["build/valid/stage#{previous}/cl", "boot/#{stage}/cl.elna", "build/boot/#{stage}"] do |t|
     exe, source = t.prerequisites
 
     cat_arguments = ['cat', source]
@@ -113,7 +129,14 @@ end
 # Stage 1.
 #
 
-file 'build/valid/stage1.s' => ['build/boot/stage1', 'boot/stage1.s', 'build/valid'] do |t|
+directory 'build/valid/stage1'
+directory 'build/boot/stage1'
+
+file 'build/valid/stage1/cl' => ['build/valid/stage1.s'] do |t|
+  compile('-nostdlib', '-o', t.name, *t.prerequisites)
+end
+
+file 'build/valid/stage1.s' => ['build/boot/stage1/cl', 'boot/stage1.s', 'build/valid/stage1'] do |t|
   source, exe, = t.prerequisites.partition { |prerequisite| prerequisite.end_with? '.s' }
 
   cat_arguments = ['cat', *source]
@@ -122,8 +145,8 @@ file 'build/valid/stage1.s' => ['build/boot/stage1', 'boot/stage1.s', 'build/val
   IO.copy_stream last_stdout, t.name
 end
 
-file 'build/boot/stage1' => ['build/boot', 'boot/stage1.s'] do |t|
+file 'build/boot/stage1/cl' => ['build/boot/stage1', 'boot/stage1.s'] do |t|
   source = t.prerequisites.select { |prerequisite| prerequisite.end_with? '.s' }
 
-  compile(*source, t.name)
+  compile('-nostdlib', '-o', t.name, *source)
 end