Implement a RISC-V backend

Rakefile

@@ -4,12 +4,13 @@ require 'open3'
 
 DFLAGS = ['--warn-no-deprecated', '-L/usr/lib64/gcc-12']
 BINARY = 'build/bin/elna'
-TESTS = FileList['tests/*.elna'].flat_map do |test|
+TESTS = FileList['tests/*.eln'].flat_map do |test|
   build = Pathname.new 'build'
-  asm_test = build + 'asm' + Pathname.new(test).basename('')
+  test_basename = Pathname.new(test).basename('')
 
-  [build + test, asm_test].map { |path| path.sub_ext('').to_path }
+  [build + 'riscv' + test_basename].map { |path| path.sub_ext('').to_path }
 end
+
 SOURCES = FileList['source/**/*.d']
 
 directory 'build'
@@ -17,27 +18,23 @@ directory 'build'
 CLEAN.include 'build'
 CLEAN.include '.dub'
 
-rule(/build\/tests\/[^\/\.]+$/ => ->(file) { test_for_out(file, '.o') }) do |t|
-  sh 'ld.gold', '-L/usr/lib64',
-    '--dynamic-linker', '/lib64/ld-linux-x86-64.so.2',
+rule(/build\/riscv\/[^\/\.]+$/ => ->(file) { test_for_out(file, '.o') }) do |t|
+  sh '/opt/riscv/bin/riscv32-unknown-elf-ld',
     '-o', t.name,
-    '/usr/lib64/crt1.o', '/usr/lib64/crti.o', '-lc', t.source, '/usr/lib64/crtn.o'
+    '-L/opt/riscv/lib/gcc/riscv32-unknown-elf/11.1.0',
+    '-L/opt/riscv/riscv32-unknown-elf/lib',
+    '/opt/riscv/riscv32-unknown-elf/lib/crt0.o',
+    '/opt/riscv/lib/gcc/riscv32-unknown-elf/11.1.0/crtbegin.o',
+    t.source,
+    '--start-group', '-lc', '-lgloss', '--end-group',
+    '/opt/riscv/lib/gcc/riscv32-unknown-elf/11.1.0/crtend.o'
 end
 
-rule(/build\/asm\/[^\/\.]+$/ => ->(file) { test_for_out(file, '.s') }) do |t|
-  sh 'gcc', '-x', 'assembler', '-o', t.name,  t.source
-end
-
-rule(/build\/tests\/.+\.o$/ => ->(file) { test_for_object(file) }) do |t|
+rule(/build\/riscv\/.+\.o$/ => ->(file) { test_for_object(file, '.eln') }) do |t|
   Pathname.new(t.name).dirname.mkpath
   sh BINARY, '-o', t.name, t.source
 end
 
-rule(/build\/asm\/.+\.s$/ => ->(file) { test_for_object(file) }) do |t|
-  Pathname.new(t.name).dirname.mkpath
-  sh BINARY, '-s', '-o', t.name, t.source
-end
-
 file BINARY => SOURCES do |t|
   sh({ 'DFLAGS' => (DFLAGS * ' ') }, 'dub', 'build', '--compiler=gdc-12')
 end
@@ -56,7 +53,13 @@ task test: BINARY do
       .to_i
 
     puts "Running #{test}"
-    system test
+    if test.include? '/riscv/'
+      system('/opt/riscv/bin/spike',
+        '/opt/riscv/riscv32-unknown-elf/bin/pk', test,
+        { out: '/dev/null' })
+    else
+      raise 'Unsupported test platform'
+    end
     actual = $?.exitstatus
 
     fail "#{test}: Expected #{expected}, got #{actual}" unless expected == actual
@@ -68,10 +71,10 @@ task unittest: SOURCES do |t|
   sh('dub', 'test', '--compiler=gdc-12')
 end
 
-def test_for_object(out_file)
+def test_for_object(out_file, extension)
   test_source = Pathname
     .new(out_file)
-    .sub_ext('.elna')
+    .sub_ext(extension)
     .sub(/^build\/[[:alpha:]]+\//, 'tests/')
     .to_path
   [test_source, BINARY]