Support simple variable assignment

Rakefile

@@ -44,13 +44,15 @@ task :convert do
   end
 end
 
-STAGES.each do |stage|
+rule /^build\/[[:alpha:]]+\/stage[[:digit:]]+$/ => ->(match) {
-  previous = stage.delete_prefix('stage').to_i.pred
+  "#{match}.s"
-
+} do |t|
-  file "build/valid/#{stage}" => "build/valid/#{stage}.s" do |t|
   sh CROSS_GCC, '-nostdlib', '-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|
     exe, source = t.prerequisites
 
@@ -61,10 +63,6 @@ STAGES.each do |stage|
     IO.copy_stream last_stdout, t.name
   end
 
-  file "build/boot/#{stage}" => "build/boot/#{stage}.s" do |t|
-    sh CROSS_GCC, '-nostdlib', '-o', t.name, *t.prerequisites
-  end
-
   file "build/boot/#{stage}.s" => ["build/valid/stage#{previous}", "boot/#{stage}.elna"] do |t|
     exe, source = t.prerequisites
 
@@ -80,12 +78,6 @@ end
 # Stage 1.
 #
 
-file 'build/valid/stage1' => ['build/valid', 'build/valid/stage1.s'] do |t|
-  source = t.prerequisites.select { |prerequisite| prerequisite.end_with? '.s' }
-
-  sh CROSS_GCC, '-nostdlib', '-o', t.name, *source
-end
-
 file 'build/valid/stage1.s' => ['build/boot/stage1', 'boot/stage1.s', 'build/valid'] do |t|
   source, exe, = t.prerequisites.partition { |prerequisite| prerequisite.end_with? '.s' }
 

boot/stage1.s

@@ -2,6 +2,11 @@
 # v. 2.0. If a copy of the MPL was not distributed with this file, You can
 # obtain one at https://mozilla.org/MPL/2.0/.
 
+# Stage1 compiler.
+#
+# It supports declaring and calling procedures without arguments.
+# A procedure name should start with an underscore.
+
 .equ SOURCE_BUFFER_SIZE, 81920
 
 .equ SYS_READ, 63

boot/stage2.elna

@@ -4,8 +4,12 @@
 
 # Stage2 compiler.
 #
-# It supports declaring and calling procedures without arguments.
+# - Procedures without none or one argument.
-# A procedure name should start with an underscore.
+# - Goto statements.
+# - Character and integer literals.
+# - Passing local variables to procedures.
+# - Local variables should have the format: v00,
+#   where 00 is its offset from the sp register.
 
 .section .rodata
 

boot/stage3.elna

@@ -4,12 +4,8 @@
 
 # Stage3 compiler.
 #
-# - Procedures without none or one argument.
+# - Procedures with multiple arguments.
-# - Goto statements.
+# - Character literals with and without escaping.
-# - Character and integer literals.
-# - Passing local variables to procedures.
-# - Local variables should have the format: v00,
-#   where 00 is its offset from the sp register.
 
 .section .rodata
 

boot/stage4.elna

@@ -2,14 +2,11 @@
 # v. 2.0. If a copy of the MPL was not distributed with this file, You can
 # obtain one at https://mozilla.org/MPL/2.0/.
 
-# Stage3 compiler.
+# Stage4 compiler.
 #
-# - Procedures without none or one argument.
+# - Taking value of local and global variables. Variables that doesn't begin
-# - Goto statements.
+#   with "v" are considered global.
-# - Character and integer literals.
+# - Simple variable assignment, e.g. v0 := 5 or v0 := global_variable;
-# - Passing local variables to procedures.
-# - Local variables should have the format: v00,
-#   where 00 is its offset from the sp register.
 
 .section .rodata
 
@@ -64,23 +61,26 @@ asm_li: .string "\tli "
 .type asm_lw, @object
 asm_lw: .string "\tlw "
 
+.type asm_la, @object
+asm_la: .string "\tla "
+
 .type asm_sw, @object
 asm_sw: .string "\tsw "
 
-.type asm_mv, @object
+.type asm_addi, @object
-asm_mv: .string "mv "
+asm_addi: .string "\taddi "
 
 .type asm_t0, @object
 asm_t0: .string "t0"
 
-.type asm_a0, @object
+.type asm_t1, @object
-asm_a0: .string "a0"
+asm_t1: .string "t1"
 
 .type asm_comma, @object
 asm_comma: .string ", "
 
 .type asm_sp, @object
-asm_sp: .string "(sp)"
+asm_sp: .string "sp"
 
 .section .bss
 
@@ -257,7 +257,7 @@ begin
 	_is_upper();
 	sw a0, 4(sp)
 
-	_is_lower(v00);
+	_is_lower(v0);
 
 	lw t0, 0(sp)
 	xori t1, t0, '_'
@@ -292,7 +292,7 @@ begin
 	_is_alpha();
 	sw a0, 0(sp)
 
-	_is_digit(v04);
+	_is_digit(v4);
 
 	lw a1, 0(sp)
 	or a0, a0, a1
@@ -491,7 +491,7 @@ begin
 	la a0, asm_li
 	_write_z();
 
-	la a0, asm_a0
+	la a0, asm_t0
 	_write_z();
 
 	la a0, asm_comma
@@ -509,7 +509,7 @@ begin
 	la a0, asm_li
 	_write_z();
 
-	la a0, asm_a0
+	la a0, asm_t0
 	_write_z();
 
 	la a0, asm_comma
@@ -542,23 +542,22 @@ end;
 
 proc _compile_variable_expression();
 begin
+	_compile_designator();
+
 	la a0, asm_lw
 	_write_z();
 
-	la a0, asm_a0
+	la a0, asm_t0
 	_write_z();
 
 	la a0, asm_comma
 	_write_z();
 
-	_advance_token(1);
+	_write_c('(');
-	_read_token();
+	la a0, asm_t0
-	_write_token();
-	_advance_token();
-
-	la a0, asm_sp
 	_write_z();
 
+	_write_c(')');
 	_write_c('\n');
 
 end;
@@ -568,17 +567,15 @@ begin
 	la t0, source_code_position
 	lw t0, (t0)
 	lb a0, (t0)
+	sw a0, 0(sp)
 
 	li t1, '\''
 	beq a0, t1, .compile_expression_character_literal
 
-	li t1, 'v'
+	_is_digit(v0);
-	beq a0, t1, .compile_expression_variable
-
-	_is_digit();
 	bnez a0, .compile_expression_integer_literal
 
-	goto .compile_expression_end;
+	goto .compile_expression_variable;
 
 .compile_expression_character_literal:
 	_compile_character_literal();
@@ -590,7 +587,7 @@ begin
 
 .compile_expression_variable:
 	_compile_variable_expression();
-	goto .compile_expression_end;;
+	goto .compile_expression_end;
 
 .compile_expression_end:
 end;
@@ -628,7 +625,7 @@ begin
 	la a0, asm_sw
 	_write_z();
 
-	la a0, asm_a0
+	la a0, asm_t0
 	_write_z();
 
 	la a0, asm_comma
@@ -642,8 +639,10 @@ begin
 	sub a0, t1, t0
 	_write_i();
 
+	_write_c('(')
 	la a0, asm_sp
 	_write_z();
+	_write_c(')')
 
 	_write_c('\n');
 
@@ -691,9 +690,11 @@ begin
 	sub a0, t1, t0
 	_write_i();
 
+	_write_c('(');
 	la a0, asm_sp
 	_write_z();
 
+	_write_c(')');
 	_write_c('\n');
 
 	goto .compile_call_finalize;
@@ -702,7 +703,7 @@ begin
 	la a0, asm_call
 	_write_z();
 
-	_write_s(v04, v00);
+	_write_s(v4, v0);
 
 	# Skip the right paren.
 	_advance_token(1);
@@ -718,10 +719,143 @@ begin
 	la a0, asm_j
 	_write_z();
 
-	_write_token(v00);
+	_write_token(v0);
 	_advance_token();
 end;
 
+proc _compile_local_designator();
+begin
+	# Skip "v" in the local variable name.
+	_advance_token(1);
+
+	la a0, asm_addi
+	_write_z();
+
+	la a0, asm_t0
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	la a0, asm_sp
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	# Read local variable stack offset and save it.
+	la t0, source_code_position
+	lw t0, (t0)
+	sw t0, 0(sp)
+
+	_read_token();
+	sw a0, 4(sp)
+
+	_write_token();
+	_advance_token();
+
+	_write_c('\n');
+
+end;
+
+proc _compile_global_designator();
+begin
+	la a0, asm_la
+	_write_z();
+
+	la a0, asm_t0
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	_read_token();
+	_write_token();
+	_advance_token();
+
+	_write_c('\n');
+
+end;
+
+proc _compile_designator();
+begin
+	la t0, source_code_position
+	lw t0, (t0)
+	lb a0, (t0)
+
+	li t1, 'v'
+	beq a0, t1, .compile_designator_local
+
+	goto .compile_designator_global;
+
+.compile_designator_local:
+	_compile_local_designator();
+	goto .compile_designator_end;
+
+.compile_designator_global:
+	_compile_global_designator();
+	goto .compile_designator_end;
+
+.compile_designator_end:
+end;
+
+proc _compile_assignment();
+begin
+	_compile_designator();
+
+	# Save the assignee address on the stack.
+	la a0, asm_sw
+	_write_z();
+
+	la a0, asm_t0
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	_write_i(20);
+	_write_c('(');
+	la a0, asm_sp
+	_write_z();
+	_write_c(')');
+	_write_c('\n');
+	# Skip the assignment sign (:=) with surrounding whitespaces.
+	_advance_token(4);
+
+	# Compile the assignment.
+	_compile_expression();
+
+	la a0, asm_lw
+	_write_z();
+
+	la a0, asm_t1
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	_write_i(20);
+	_write_c('(');
+	la a0, asm_sp
+	_write_z();
+	_write_c(')');
+	_write_c('\n');
+
+	la a0, asm_sw
+	_write_z();
+
+	la a0, asm_t0
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	_write_c('(');
+	la a0, asm_t1
+	_write_z();
+	_write_c(')');
+end;
+
 proc _compile_statement();
 begin
 	# This is a call if the statement starts with an underscore.
@@ -737,6 +871,9 @@ begin
 	li t1, 'g'
 	beq t0, t1, .compile_statement_goto
 
+	li t1, 'v'
+	beq t0, t1, .compile_statement_assignment
+
 	_compile_line();
 	goto .compile_statement_end;
 
@@ -752,6 +889,12 @@ begin
 
 	goto .compile_statement_semicolon;
 
+.compile_statement_assignment:
+	_advance_token(1);
+	_compile_assignment();
+
+	goto .compile_statement_semicolon;
+
 .compile_statement_semicolon:
 	_advance_token(2);
 
@@ -789,13 +932,13 @@ begin
 	la a0, asm_type_directive
 	_write_z();
 
-	_write_token(v00);
+	_write_token(v0);
 
 	la a0, asm_type_function
 	_write_z();
 
 	# Write procedure label, _procedure_name:
-	_write_token(v00);
+	_write_token(v0);
 
 	la a0, asm_colon
 	_write_z();

boot/stage5.elna

@@ -2,14 +2,8 @@
 # v. 2.0. If a copy of the MPL was not distributed with this file, You can
 # obtain one at https://mozilla.org/MPL/2.0/.
 
-# Stage3 compiler.
+# Stage5 compiler.
 #
-# - Procedures without none or one argument.
-# - Goto statements.
-# - Character and integer literals.
-# - Passing local variables to procedures.
-# - Local variables should have the format: v00,
-#   where 00 is its offset from the sp register.
 
 .section .rodata
 
@@ -64,23 +58,26 @@ asm_li: .string "\tli "
 .type asm_lw, @object
 asm_lw: .string "\tlw "
 
+.type asm_la, @object
+asm_la: .string "\tla "
+
 .type asm_sw, @object
 asm_sw: .string "\tsw "
 
-.type asm_mv, @object
+.type asm_addi, @object
-asm_mv: .string "mv "
+asm_addi: .string "\taddi "
 
 .type asm_t0, @object
 asm_t0: .string "t0"
 
-.type asm_a0, @object
+.type asm_t1, @object
-asm_a0: .string "a0"
+asm_t1: .string "t1"
 
 .type asm_comma, @object
 asm_comma: .string ", "
 
 .type asm_sp, @object
-asm_sp: .string "(sp)"
+asm_sp: .string "sp"
 
 .section .bss
 
@@ -257,7 +254,7 @@ begin
 	_is_upper();
 	sw a0, 4(sp)
 
-	_is_lower(v00);
+	_is_lower(v0);
 
 	lw t0, 0(sp)
 	xori t1, t0, '_'
@@ -289,10 +286,10 @@ proc _is_alnum();
 begin
 	sw a0, 4(sp)
 
-	_is_alpha();
+	_is_alpha(v4);
 	sw a0, 0(sp)
 
-	_is_digit(v04);
+	_is_digit(v4);
 
 	lw a1, 0(sp)
 	or a0, a0, a1
@@ -413,12 +410,7 @@ end;
 proc _write_token();
 begin
 	sw a0, 0(sp)
-
+	_write_s(source_code_position, v0);
-	la a0, source_code_position
-	lw a0, (a0)
-	lw a1, 0(sp)
-	_write_s();
-
 	lw a0, 0(sp)
 end;
 
@@ -491,7 +483,7 @@ begin
 	la a0, asm_li
 	_write_z();
 
-	la a0, asm_a0
+	la a0, asm_t0
 	_write_z();
 
 	la a0, asm_comma
@@ -509,7 +501,7 @@ begin
 	la a0, asm_li
 	_write_z();
 
-	la a0, asm_a0
+	la a0, asm_t0
 	_write_z();
 
 	la a0, asm_comma
@@ -542,23 +534,22 @@ end;
 
 proc _compile_variable_expression();
 begin
+	_compile_designator();
+
 	la a0, asm_lw
 	_write_z();
 
-	la a0, asm_a0
+	la a0, asm_t0
 	_write_z();
 
 	la a0, asm_comma
 	_write_z();
 
-	_advance_token(1);
+	_write_c('(');
-	_read_token();
+	la a0, asm_t0
-	_write_token();
-	_advance_token();
-
-	la a0, asm_sp
 	_write_z();
 
+	_write_c(')');
 	_write_c('\n');
 
 end;
@@ -568,17 +559,15 @@ begin
 	la t0, source_code_position
 	lw t0, (t0)
 	lb a0, (t0)
+	sw a0, 0(sp)
 
 	li t1, '\''
 	beq a0, t1, .compile_expression_character_literal
 
-	li t1, 'v'
+	_is_digit(v0);
-	beq a0, t1, .compile_expression_variable
-
-	_is_digit();
 	bnez a0, .compile_expression_integer_literal
 
-	goto .compile_expression_end;
+	goto .compile_expression_variable;
 
 .compile_expression_character_literal:
 	_compile_character_literal();
@@ -590,7 +579,7 @@ begin
 
 .compile_expression_variable:
 	_compile_variable_expression();
-	goto .compile_expression_end;;
+	goto .compile_expression_end;
 
 .compile_expression_end:
 end;
@@ -604,11 +593,8 @@ begin
 
 	_read_token();
 	sw a0, 0(sp)
-	la t0, source_code_position
+	v4 := source_code_position;
-	lw t0, (t0)
+	v8 := 0;
-	sw t0, 4(sp)
-
-	sw zero, 8(sp)
 
 	# Skip the identifier and left paren.
 	addi a0, a0, 1
@@ -628,7 +614,7 @@ begin
 	la a0, asm_sw
 	_write_z();
 
-	la a0, asm_a0
+	la a0, asm_t0
 	_write_z();
 
 	la a0, asm_comma
@@ -642,8 +628,10 @@ begin
 	sub a0, t1, t0
 	_write_i();
 
+	_write_c('(')
 	la a0, asm_sp
 	_write_z();
+	_write_c(')')
 
 	_write_c('\n');
 
@@ -677,8 +665,7 @@ begin
 	_write_z();
 
 	_write_c('a');
-	lw a0, 8(sp)
+	_write_i(v8);
-	_write_i();
 
 	la a0, asm_comma
 	_write_z();
@@ -691,9 +678,11 @@ begin
 	sub a0, t1, t0
 	_write_i();
 
+	_write_c('(');
 	la a0, asm_sp
 	_write_z();
 
+	_write_c(')');
 	_write_c('\n');
 
 	goto .compile_call_finalize;
@@ -702,7 +691,7 @@ begin
 	la a0, asm_call
 	_write_z();
 
-	_write_s(v04, v00);
+	_write_s(v4, v0);
 
 	# Skip the right paren.
 	_advance_token(1);
@@ -718,10 +707,142 @@ begin
 	la a0, asm_j
 	_write_z();
 
-	_write_token(v00);
+	_write_token(v0);
 	_advance_token();
 end;
 
+proc _compile_local_designator();
+begin
+	# Skip "v" in the local variable name.
+	_advance_token(1);
+
+	la a0, asm_addi
+	_write_z();
+
+	la a0, asm_t0
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	la a0, asm_sp
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	# Read local variable stack offset and save it.
+	v0 := source_code_position;
+
+	_read_token();
+	sw a0, 4(sp)
+
+	_write_token();
+	_advance_token();
+
+	_write_c('\n');
+
+end;
+
+proc _compile_global_designator();
+begin
+	la a0, asm_la
+	_write_z();
+
+	la a0, asm_t0
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	_read_token();
+	_write_token();
+	_advance_token();
+
+	_write_c('\n');
+
+end;
+
+proc _compile_designator();
+begin
+	la t0, source_code_position
+	lw t0, (t0)
+	lb a0, (t0)
+
+	li t1, 'v'
+	beq a0, t1, .compile_designator_local
+
+	goto .compile_designator_global;
+
+.compile_designator_local:
+	_compile_local_designator();
+	goto .compile_designator_end;
+
+.compile_designator_global:
+	_compile_global_designator();
+	goto .compile_designator_end;
+
+.compile_designator_end:
+end;
+
+proc _compile_assignment();
+begin
+	_compile_designator();
+
+	# Save the assignee address on the stack.
+	la a0, asm_sw
+	_write_z();
+
+	la a0, asm_t0
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	_write_i(20);
+	_write_c('(');
+	la a0, asm_sp
+	_write_z();
+	_write_c(')');
+	_write_c('\n');
+
+	# Skip the assignment sign (:=) with surrounding whitespaces.
+	_advance_token(4);
+
+	# Compile the assignment.
+	_compile_expression();
+
+	la a0, asm_lw
+	_write_z();
+
+	la a0, asm_t1
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	_write_i(20);
+	_write_c('(');
+	la a0, asm_sp
+	_write_z();
+	_write_c(')');
+	_write_c('\n');
+
+	la a0, asm_sw
+	_write_z();
+
+	la a0, asm_t0
+	_write_z();
+
+	la a0, asm_comma
+	_write_z();
+
+	_write_c('(');
+	la a0, asm_t1
+	_write_z();
+	_write_c(')');
+end;
+
 proc _compile_statement();
 begin
 	# This is a call if the statement starts with an underscore.
@@ -737,6 +858,9 @@ begin
 	li t1, 'g'
 	beq t0, t1, .compile_statement_goto
 
+	li t1, 'v'
+	beq t0, t1, .compile_statement_assignment
+
 	_compile_line();
 	goto .compile_statement_end;
 
@@ -752,6 +876,12 @@ begin
 
 	goto .compile_statement_semicolon;
 
+.compile_statement_assignment:
+	_advance_token(1);
+	_compile_assignment();
+
+	goto .compile_statement_semicolon;
+
 .compile_statement_semicolon:
 	_advance_token(2);
 
@@ -789,13 +919,13 @@ begin
 	la a0, asm_type_directive
 	_write_z();
 
-	_write_token(v00);
+	_write_token(v0);
 
 	la a0, asm_type_function
 	_write_z();
 
 	# Write procedure label, _procedure_name:
-	_write_token(v00);
+	_write_token(v0);
 
 	la a0, asm_colon
 	_write_z();
@@ -834,9 +964,6 @@ begin
 
 	# Read the symbol type.
 	_read_token();
-	la t0, source_code_position
-	lw t0, (t0)
-	sw t0, 12(sp)
 
 	# Print the symbol type and newline.
 	addi a0, a0, 1

rakelib/cross.rake

@@ -1,323 +0,0 @@
-# This Source Code Form is subject to the terms of the Mozilla Public License,
-# v. 2.0. If a copy of the MPL was not distributed with this file, You can
-# obtain one at https://mozilla.org/MPL/2.0/. -}
-# frozen_string_literal: true
-
-require 'pathname'
-require 'uri'
-require 'net/http'
-require 'rake/clean'
-require 'open3'
-require 'etc'
-
-GCC_VERSION = "15.1.0"
-BINUTILS_VERSION = '2.44'
-GLIBC_VERSION = '2.41'
-KERNEL_VERSION = '5.15.181'
-
-CLOBBER.include 'build'
-
-class BuildTarget
-  attr_accessor(:build, :gcc, :target, :tmp)
-
-  def gxx
-    @gcc.gsub 'c', '+'
-  end
-
-  def sysroot
-    tmp + 'sysroot'
-  end
-
-  def rootfs
-    tmp + 'rootfs'
-  end
-
-  def tools
-    tmp + 'tools'
-  end
-end
-
-def gcc_verbose(gcc_binary)
-  read, write = IO.pipe
-  sh({'LANG' => 'C'}, gcc_binary, '--verbose', err: write)
-  write.close
-  output = read.read
-  read.close
-  output
-end
-
-def find_build_target(gcc_version, task)
-  gcc_binary = 'gcc'
-  output = gcc_verbose gcc_binary
-
-  if output.start_with? 'Apple clang'
-    gcc_binary = "gcc-#{gcc_version.split('.').first}"
-    output = gcc_verbose gcc_binary
-  end
-  result = output
-    .lines
-    .each_with_object(BuildTarget.new) do |line, accumulator|
-      if line.start_with? 'Target: '
-        accumulator.build = line.split(' ').last.strip
-      elsif line.start_with? 'COLLECT_GCC'
-        accumulator.gcc = line.split('=').last.strip
-      end
-    end
-  result.tmp = Pathname.new('./build')
-  task.with_defaults target: 'riscv32-unknown-linux-gnu'
-  result.target = task[:target]
-  result
-end
-
-def download_and_unarchive(url, target)
-  case File.extname url.path
-  when '.bz2'
-    archive_type = '-j'
-    root_directory = File.basename url.path, '.tar.bz2'
-  when '.xz'
-    archive_type = '-J'
-    root_directory = File.basename url.path, '.tar.xz'
-  else
-    raise "Unsupported archive type #{url.path}."
-  end
-
-  Net::HTTP.start(url.host, url.port, use_ssl: url.scheme == 'https') do |http|
-    request = Net::HTTP::Get.new url.request_uri
-
-    http.request request do |response|
-      case response
-      when Net::HTTPRedirection
-        download_and_unarchive URI.parse(response['location'])
-      when Net::HTTPSuccess
-        Open3.popen2 'tar', '-C', target.to_path, archive_type, '-xv' do |stdin, stdout, wait_thread|
-          Thread.new do
-            stdout.each { |line| puts line }
-          end
-
-          response.read_body do |chunk|
-            stdin.write chunk
-          end
-          stdin.close
-
-          wait_thread.value
-        end
-      else
-        response.error!
-      end
-    end
-  end
-  target + root_directory
-end
-
-namespace :cross do
-  desc 'Build cross binutils'
-  task :binutils, [:target] do |_, args|
-    options = find_build_target GCC_VERSION, args
-    options.tools.mkpath
-    source_directory = download_and_unarchive(
-      URI.parse("https://ftp.gnu.org/gnu/binutils/binutils-#{BINUTILS_VERSION}.tar.xz"),
-      options.tools)
-
-    cwd = source_directory.dirname + 'build-binutils'
-    cwd.mkpath
-    options.rootfs.mkpath
-
-    env = {
-     'CC' => options.gcc,
-     'CXX' => options.gxx
-    }
-    configure_options = [
-      "--prefix=#{options.rootfs.realpath}",
-      "--target=#{options.target}",
-      '--disable-nls',
-      '--enable-gprofng=no',
-      '--disable-werror',
-      '--enable-default-hash-style=gnu',
-      '--disable-libquadmath'
-    ]
-    configure = source_directory.relative_path_from(cwd) + 'configure'
-    sh env, configure.to_path, *configure_options, chdir: cwd.to_path
-    sh env, 'make', '-j', Etc.nprocessors.to_s, chdir: cwd.to_path
-    sh env, 'make', 'install', chdir: cwd.to_path
-  end
-
-  desc 'Build stage 1 GCC'
-  task :gcc1, [:target] do |_, args|
-    options = find_build_target GCC_VERSION, args
-    options.tools.mkpath
-    source_directory = download_and_unarchive(
-      URI.parse("https://gcc.gnu.org/pub/gcc/releases/gcc-#{GCC_VERSION}/gcc-#{GCC_VERSION}.tar.xz"),
-      options.tools)
-
-    cwd = source_directory.dirname + 'build-gcc'
-    cwd.mkpath
-    options.rootfs.mkpath
-    options.sysroot.mkpath
-
-    sh 'contrib/download_prerequisites', chdir: source_directory.to_path
-    configure_options = [
-      "--prefix=#{options.rootfs.realpath}",
-      "--with-sysroot=#{options.sysroot.realpath}",
-      '--enable-languages=c,c++',
-      '--disable-shared',
-      '--with-arch=rv32imafdc',
-      '--with-abi=ilp32d',
-      '--with-tune=rocket',
-      '--with-isa-spec=20191213',
-      '--disable-bootstrap',
-      '--disable-multilib',
-      '--disable-libmudflap',
-      '--disable-libssp',
-      '--disable-libquadmath',
-      '--disable-libsanitizer',
-      '--disable-threads',
-      '--disable-libatomic',
-      '--disable-libgomp',
-      '--disable-libvtv',
-      '--disable-libstdcxx',
-      '--disable-nls',
-      '--with-newlib',
-      '--without-headers',
-      "--target=#{options.target}",
-      "--build=#{options.build}",
-      "--host=#{options.build}"
-    ]
-    flags = '-O2 -fPIC'
-    env = {
-      'CC' => options.gcc,
-      'CXX' => options.gxx,
-      'CFLAGS' => flags,
-      'CXXFLAGS' => flags,
-      'PATH' => "#{options.rootfs.realpath + 'bin'}:#{ENV['PATH']}"
-    }
-    configure = source_directory.relative_path_from(cwd) + 'configure'
-    sh env, configure.to_path, *configure_options, chdir: cwd.to_path
-    sh env, 'make', '-j', Etc.nprocessors.to_s, chdir: cwd.to_path
-    sh env, 'make', 'install', chdir: cwd.to_path
-  end
-
-  desc 'Copy glibc headers'
-  task :headers, [:target] do |_, args|
-    options = find_build_target GCC_VERSION, args
-    options.tools.mkpath
-
-    source_directory = download_and_unarchive(
-      URI.parse("https://ftp.gnu.org/gnu/glibc/glibc-#{GLIBC_VERSION}.tar.xz"),
-      options.tools)
-    include_directory = options.tools + 'include'
-
-    include_directory.mkpath
-    cp (source_directory + 'elf/elf.h'), (include_directory + 'elf.h')
-  end
-
-  desc 'Build linux kernel'
-  task :kernel, [:target] do |_, args|
-    options = find_build_target GCC_VERSION, args
-    options.tools.mkpath
-
-    cwd = download_and_unarchive(
-      URI.parse("https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-#{KERNEL_VERSION}.tar.xz"),
-      options.tools)
-
-    env = {
-      'CROSS_COMPILE' => "#{options.target}-",
-      'ARCH' => 'riscv',
-      'PATH' => "#{options.rootfs.realpath + 'bin'}:#{ENV['PATH']}",
-      'HOSTCFLAGS' => "-D_UUID_T -D__GETHOSTUUID_H -I#{options.tools.realpath + 'include'}"
-    }
-    sh env, 'make', 'rv32_defconfig', chdir: cwd.to_path
-    sh env, 'make', '-j', Etc.nprocessors.to_s, chdir: cwd.to_path
-    sh env, 'make', 'headers', chdir: cwd.to_path
-
-    user_directory = options.sysroot + 'usr'
-
-    user_directory.mkpath
-    cp_r (cwd + 'usr/include'), (user_directory + 'include')
-  end
-
-  desc 'Build glibc'
-  task :glibc, [:target] do |_, args|
-    options = find_build_target GCC_VERSION, args
-    source_directory = options.tools + "glibc-#{GLIBC_VERSION}"
-    configure_options = [
-      '--prefix=/usr',
-      "--host=#{options.target}",
-      "--target=#{options.target}",
-      "--build=#{options.build}",
-      "--enable-kernel=#{KERNEL_VERSION}",
-      "--with-headers=#{options.sysroot.realpath + 'usr/include'}",
-      '--disable-nscd',
-      '--disable-libquadmath',
-      '--disable-libitm',
-      '--disable-werror',
-      'libc_cv_forced_unwind=yes'
-    ]
-    bin = options.rootfs.realpath + 'bin'
-    env = {
-      'PATH' => "#{bin}:#{ENV['PATH']}",
-      'MAKE' => 'make' # Otherwise it uses gnumake which can be different and too old.
-    }
-    cwd = source_directory.dirname + 'build-glibc'
-    cwd.mkpath
-
-    configure = source_directory.relative_path_from(cwd) +'./configure'
-    sh env, configure.to_path, *configure_options, chdir: cwd.to_path
-    sh env, 'make', '-j', Etc.nprocessors.to_s, chdir: cwd.to_path
-    sh env, 'make', "install_root=#{options.sysroot.realpath}", 'install', chdir: cwd.to_path
-  end
-
-  desc 'Build stage 2 GCC'
-  task :gcc2, [:target] do |_, args|
-    options = find_build_target GCC_VERSION, args
-    source_directory = options.tools + "gcc-#{GCC_VERSION}"
-    cwd = options.tools + 'build-gcc'
-
-    rm_rf cwd
-    cwd.mkpath
-
-    configure_options = [
-      "--prefix=#{options.rootfs.realpath}",
-      "--with-sysroot=#{options.sysroot.realpath}",
-      '--enable-languages=c,c++,lto',
-      '--enable-lto',
-      '--enable-shared',
-      '--with-arch=rv32imafdc',
-      '--with-abi=ilp32d',
-      '--with-tune=rocket',
-      '--with-isa-spec=20191213',
-      '--disable-bootstrap',
-      '--disable-multilib',
-      '--enable-checking=release',
-      '--disable-libssp',
-      '--disable-libquadmath',
-      '--enable-threads=posix',
-      '--with-default-libstdcxx-abi=new',
-      '--disable-nls',
-      "--target=#{options.target}",
-      "--build=#{options.build}",
-      "--host=#{options.build}"
-
-    ]
-    flags = '-O2 -fPIC'
-    env = {
-      'CFLAGS' => flags,
-      'CXXFLAGS' => flags,
-      'PATH' => "#{options.rootfs.realpath + 'bin'}:#{ENV['PATH']}"
-    }
-    configure = source_directory.relative_path_from(cwd) + 'configure'
-    sh env, configure.to_path, *configure_options, chdir: cwd.to_path
-    sh env, 'make', '-j', Etc.nprocessors.to_s, chdir: cwd.to_path
-    sh env, 'make', 'install', chdir: cwd.to_path
-  end
-end
-
-desc 'Build cross toolchain'
-task cross: [
-  'cross:binutils',
-  'cross:gcc1',
-  'cross:headers',
-  'cross:kernel',
-  'cross:glibc',
-  'cross:gcc2'
-] do
-end