Add symbol info for parameters and local variables

Rakefile

@@ -20,3 +20,19 @@ task default: ['build/boot/stage2b', 'build/boot/stage2b.s', 'boot/stage2.elna']
   diff_arguments = ['diff', '-Nur', '--text', previous_output, '-']
   Open3.pipeline(cat_arguments, compiler_arguments, diff_arguments)
 end
+
+file 'build/boot/test.s' => ['build/boot/stage1', 'boot/test.elna'] do |t|
+  source, exe = t.prerequisites.partition { |prerequisite| prerequisite.end_with? '.elna' }
+
+  File.open t.name, 'w' do |output|
+    assemble_stage output, exe, source
+  end
+end
+
+file 'build/boot/test' => ['build/boot/test.s', 'boot/common-boot.s'] do |t|
+  sh CROSS_GCC, '-nostdlib', '-o', t.name, *t.prerequisites
+end
+
+task test: 'build/boot/test' do |t|
+  sh QEMU, '-L', SYSROOT, t.prerequisites.first
+end

boot/definitions.inc

@@ -62,3 +62,5 @@
 #
 .equ TYPE_PRIMITIVE, 0x01
 .equ TYPE_POINTER, 0x02
+.equ INFO_PARAMETER, 0x10
+.equ INFO_LOCAL, 0x20

boot/stage1.s

@@ -85,8 +85,8 @@ source_code: .zero SOURCE_BUFFER_SIZE
 .section .text
 
 # Ignores the import.
-.type _compile_import, @function
+.type compile_import, @function
-_compile_import:
+compile_import:
 	# Prologue.
 	addi sp, sp, -24
 	sw ra, 20(sp)
@@ -227,8 +227,8 @@ compile_binary_expression:
 # a1 - Identifier length.
 #
 # Sets a0 to 1 if the identifier starts with "loca", otherwise to 0.
-.type _is_local_identifier, @function
+.type is_local_identifier, @function
-_is_local_identifier:
+is_local_identifier:
 	# Prologue.
 	addi sp, sp, -16
 	sw ra, 12(sp)
@@ -255,8 +255,8 @@ _is_local_identifier:
 # a1 - Identifier length.
 #
 # Sets a0 to 1 if the identifier is a preserved register, otherwise to 0.
-.type _is_register_identifier, @function
+.type is_register_identifier, @function
-_is_register_identifier:
+is_register_identifier:
 	# Prologue.
 	addi sp, sp, -8
 	sw ra, 4(sp)
@@ -279,8 +279,8 @@ _is_register_identifier:
 # Parameters:
 # a0 - Identifier length.
 # a1 - Register number as character.
-.type _compile_identifier_expression, @function
+.type compile_identifier_expression, @function
-_compile_identifier_expression:
+compile_identifier_expression:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -290,24 +290,32 @@ _compile_identifier_expression:
 	sw a0, 20(sp) # Identifier length.
 	sw a1, 16(sp) # Register number as character.
 
+	lw a0, 20(sp)
+	mv a1, s1
+	call symbol_table_find
+	sw a0, 12(sp)
+
 	mv a0, s1
 	lw a1, 20(sp)
-	call _is_local_identifier
+	call is_local_identifier
 	bnez a0, .Lcompile_identifier_expression_local
 
 	mv a0, s1
 	lw a1, 20(sp)
-	call _is_register_identifier
+	call is_register_identifier
 	bnez a0, .Lcompile_identifier_expression_saved
 
+	lw t0, 12(sp)
+	bnez t0, .Lcompile_identifier_expression_defined
+
 	# Global identifier.
 	lw t1, 16(sp)
 	li t0, 0x00202c00 # \0,_
 	or t0, t0, t1
-	sw t0, 12(sp)
-	li t0, 0x6120616c # la a
 	sw t0, 8(sp)
-	addi a0, sp, 8
+	li t0, 0x6120616c # la a
+	sw t0, 4(sp)
+	addi a0, sp, 4
 	li a1, 7
 	call _write_out
 
@@ -326,26 +334,51 @@ _compile_identifier_expression:
 	li t0, 0x0a290061 # a\0)\n
 	sll t2, t1, 8
 	or t0, t0, t2
-	sw t0, 12(sp)
+	sw t0, 8(sp)
 	li t0, 0x28202c00 # \0, (
 	or t0, t0, t1
+	sw t0, 4(sp)
+	li t0, 0x6120776c # lw a
+	sw t0, 0(sp)
+	addi a0, sp, 0
+	li a1, 12
+	call _write_out
+
+	j .Lcompile_identifier_expression_end
+
+.Lcompile_identifier_expression_defined:
+	lw t1, 16(sp)
+	li t0, 0x00202c00 # \0,_
+	or t0, t0, t1
 	sw t0, 8(sp)
 	li t0, 0x6120776c # lw a
 	sw t0, 4(sp)
 	addi a0, sp, 4
-	li a1, 12
+	li a1, 7
 	call _write_out
 
+	lw a0, 12(sp)
+	lw a0, 8(a0)
+	call _printi
+
+	li t0, 0x29707328 # (sp)
+	sw t0, 8(sp)
+	addi a0, sp, 8
+	li a1, 4
+	call _write_out
+	li a0, '\n'
+	call _put_char
+
 	j .Lcompile_identifier_expression_end
 
 .Lcompile_identifier_expression_saved:
 	li t0, 0x00202c00 # \0,_
 	lw t1, 16(sp)
 	or t0, t0, t1
-	sw t0, 12(sp)
-	li t0, 0x6120766d # mv a
 	sw t0, 8(sp)
-	addi a0, sp, 8
+	li t0, 0x6120766d # mv a
+	sw t0, 4(sp)
+	addi a0, sp, 4
 	li a1, 7
 	call _write_out
 
@@ -362,10 +395,10 @@ _compile_identifier_expression:
 	lw t1, 16(sp)
 	li t0, 0x00202c00 # \0,_
 	or t0, t0, t1
-	sw t0, 12(sp)
-	li t0, 0x6120776c # lw a
 	sw t0, 8(sp)
-	addi a0, sp, 8
+	li t0, 0x6120776c # lw a
+	sw t0, 4(sp)
+	addi a0, sp, 4
 	li a1, 7
 	call _write_out
 
@@ -376,8 +409,8 @@ _compile_identifier_expression:
 	call _write_out
 
 	li t0, 0x29707328 # (sp)
-	sw t0, 12(sp)
+	sw t0, 8(sp)
-	addi a0, sp, 12
+	addi a0, sp, 8
 	li a1, 4
 	call _write_out
 	li a0, '\n'
@@ -431,7 +464,7 @@ _build_expression:
 	lw s1, 32(sp)
 	lw a0, 28(sp)
 	lw a1, 36(sp)
-	call _compile_identifier_expression
+	call compile_identifier_expression
 
 	j .Lbuild_expression_advance
 
@@ -485,7 +518,7 @@ _build_expression:
 
 	lw a0, 32(sp)
 	lw a1, 28(sp)
-	call _compile_call
+	call compile_call
 
 	j .Lbuild_expression_end
 
@@ -524,8 +557,8 @@ _build_expression:
 # Parameters:
 # a0 - Pointer to the identifier.
 # a1 - Identifier length.
-.type _compile_designator_expression, @function
+.type compile_designator_expression, @function
-_compile_designator_expression:
+compile_designator_expression:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -537,12 +570,12 @@ _compile_designator_expression:
 
 	lw a0, 20(sp)
 	lw a1, 16(sp)
-	call _is_local_identifier
+	call is_local_identifier
 	bnez a0, .Lcompile_designator_expression_local
 
 	lw a0, 20(sp)
 	lw a1, 16(sp)
-	call _is_register_identifier
+	call is_register_identifier
 	bnez a0, .Lcompile_designator_expression_saved
 
 .Lcompile_designator_expression_local:
@@ -603,8 +636,8 @@ _compile_designator_expression:
 #
 # Left values should be variables named "loca n", where n is the offset
 # of the variable on the stack, like loca8 or loca4.
-.type _compile_identifier, @function
+.type compile_identifier, @function
-_compile_identifier:
+compile_identifier:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -632,7 +665,7 @@ _compile_identifier:
 .Lcompile_identifier_call:
 	lw a0, 20(sp)
 	lw a1, 16(sp)
-	call _compile_call
+	call compile_call
 
 	j .Lcompile_identifier_end
 
@@ -640,7 +673,7 @@ _compile_identifier:
 	call compile_binary_expression
 	lw a0, 20(sp)
 	lw a1, 16(sp)
-	call _compile_designator_expression
+	call compile_designator_expression
 
 	j .Lcompile_identifier_end
 
@@ -656,8 +689,8 @@ _compile_identifier:
 # a1 - Length of the procedure name.
 #
 # Returns the procedure result in a0.
-.type _compile_call, @function
+.type compile_call, @function
-_compile_call:
+compile_call:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -748,8 +781,8 @@ _compile_call:
 	ret
 
 # Walks through the procedure definitions.
-.type _compile_procedure_section, @function
+.type compile_procedure_section, @function
-_compile_procedure_section:
+compile_procedure_section:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -764,7 +797,7 @@ _compile_procedure_section:
 	lw t1, 4(sp)
 	bne t0, t1, .Lcompile_procedure_section_end
 
-	call _compile_procedure
+	call compile_procedure
 
 	j .Lcompile_procedure_section_loop
 
@@ -775,8 +808,8 @@ _compile_procedure_section:
 	addi sp, sp, 32
 	ret
 
-.type _compile_module_declaration, @function
+.type compile_module_declaration, @function
-_compile_module_declaration:
+compile_module_declaration:
 	# Prologue.
 	addi sp, sp, -24
 	sw ra, 20(sp)
@@ -799,8 +832,8 @@ _compile_module_declaration:
 	addi sp, sp, 24
 	ret
 
-.type _compile_constant_section, @function
+.type compile_constant_section, @function
-_compile_constant_section:
+compile_constant_section:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -830,7 +863,7 @@ _compile_constant_section:
 	bne t0, t1, .Lcompile_constant_section_end
 	lw s1, 20(sp)
 
-	call _compile_constant
+	call compile_constant
 	j .Lcompile_constant_section_item
 
 .Lcompile_constant_section_end:
@@ -840,8 +873,8 @@ _compile_constant_section:
 	addi sp, sp, 32
 	ret
 
-.type _compile_constant, @function
+.type compile_constant, @function
-_compile_constant:
+compile_constant:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -886,8 +919,9 @@ _compile_constant:
 	addi sp, sp, 32
 	ret
 
-.type _compile_variable_section, @function
+# Compiles global variable section.
-_compile_variable_section:
+.type compile_global_section, @function
+compile_global_section:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -899,36 +933,37 @@ _compile_variable_section:
 	call lex_next
 	li t0, TOKEN_VAR
 	lw t1, 4(sp)
-	bne t0, t1, .Lcompile_variable_section_end
+	bne t0, t1, .Lcompile_global_section_end
 	mv s1, a0
 
 	la a0, section_bss
 	li a1, SECTION_BSS_SIZE
 	call _write_out
 
-.Lcompile_variable_section_item:
+.Lcompile_global_section_item:
 	mv a0, s1
 	addi a1, sp, 12
 	call lex_next
+
 	lw t0, 12(sp)
 	li t1, TOKEN_IDENTIFIER
 
-	bne t0, t1, .Lcompile_variable_section_end
+	bne t0, t1, .Lcompile_global_section_end
 	lw s1, 20(sp) # Advance to the beginning of the variable name.
 
-	call _compile_variable
+	call compile_global
-	j .Lcompile_variable_section_item
+	j .Lcompile_global_section_item
 
-.Lcompile_variable_section_end:
+.Lcompile_global_section_end:
 	# Epilogue.
 	lw ra, 28(sp)
 	lw s0, 24(sp)
 	addi sp, sp, 32
 	ret
 
-# Compile a global variable.
+# Compiles a global variable.
-.type _compile_variable, @function
+.type compile_global, @function
-_compile_variable:
+compile_global:
 	# Prologue.
 	addi sp, sp, -48
 	sw ra, 44(sp)
@@ -1010,29 +1045,10 @@ compile_type_expression:
 	beq t0, t1, .Lcompile_type_expression_pointer
 
 	# Named type.
-	mv a0, zero
+	lw a0, 16(sp)
-	lw a1, 16(sp)
+	lw a1, 20(sp)
-	lw a2, 20(sp)
 	call symbol_table_find
 
-	/* DEBUG
-	sw a0, 4(sp)
-
-	lw a0, 4(a0)
-	addi a0, a0, '0'
-	sw a0, 8(sp)
-
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call _write_error
-
-	addi a0, sp, 8
-	li a1, 1
-	call _write_error
-
-	lw a0, 4(sp) */
-	/* DEBUG */
-
 	j .Lcompile_type_expression_end
 
 .Lcompile_type_expression_pointer:
@@ -1051,24 +1067,87 @@ compile_type_expression:
 	addi sp, sp, 32
 	ret
 
-.type _compile_parameters, @function
+# Inserts local procedure variables into the symbol table.
-_compile_parameters:
+.type compile_local_section, @function
+compile_local_section:
 	# Prologue.
-	addi sp, sp, -32
+	addi sp, sp, -48
-	sw ra, 28(sp)
+	sw ra, 44(sp)
-	sw s0, 24(sp)
+	sw s0, 40(sp)
-	addi s0, sp, 32
+	addi s0, sp, 48
 
 	mv a0, s1
-	addi a1, sp, 12
+	addi a1, sp, 28
+	call lex_next
+
+	lw t0, 28(sp)
+	li t1, TOKEN_VAR
+
+	bne t0, t1, .Lcompile_local_section_end
+	mv s1, a0
+
+	sw zero, 12(sp) # Variable offset counter.
+
+.Lcompile_local_section_variable:
+	mv a0, s1
+	addi a1, sp, 28
+	call lex_next
+
+	lw t0, 28(sp)
+	li t1, TOKEN_IDENTIFIER
+
+	bne t0, t1, .Lcompile_local_section_end
+	addi a1, sp, 16
+	call lex_next
+	mv s1, a0 # Skip the ":" in front of the type.
+
+	call compile_type_expression
+	# a0 - Variable type.
+	lw a1, 12(sp)
+	mv a2, s3
+	call symbol_table_make_local
+
+	mv a2, s3
+	add s3, s3, a0
+
+	lw a0, 32(sp)
+	lw a1, 36(sp)
+	call symbol_table_insert
+
+	lw t0, 12(sp)
+	addi t0, t0, 4
+	sw t0, 12(sp)
+
+	j .Lcompile_local_section_variable
+
+.Lcompile_local_section_end:
+	# Epilogue.
+	lw ra, 44(sp)
+	lw s0, 40(sp)
+	addi sp, sp, 48
+	ret
+
+# Inserts procedure parameters into the symbol table.
+.type compile_parameters, @function
+compile_parameters:
+	# Prologue.
+	addi sp, sp, -48
+	sw ra, 44(sp)
+	sw s0, 40(sp)
+	addi s0, sp, 48
+
+	sw zero, 12(sp) # Parameter offset counter.
+
+	mv a0, s1
+	addi a1, sp, 28
 	call lex_next
 	mv s1, a0 # Skip the opening paren.
 
 	mv a0, s1
-	addi a1, sp, 12
+	addi a1, sp, 28
 	call lex_next
 
-	lw t0, 12(sp)
+	lw t0, 28(sp)
 	li t1, TOKEN_RIGHT_PAREN
 	beq t0, t1, .Lcompile_parameters_end
 	# When this is not the right paren, it is an identifier.
@@ -1076,21 +1155,37 @@ _compile_parameters:
 
 .Lcompile_parameters_parameter:
 	mv a0, s1
-	addi a1, sp, 0
+	addi a1, sp, 16
 	call lex_next
 	mv s1, a0 # Skip the ":" in front of the type.
 
 	call compile_type_expression
+	# a0 - Parameter type.
+	lw a1, 12(sp)
+	mv a2, s3
+	call symbol_table_make_parameter
+
+	mv a2, s3
+	add s3, s3, a0
+
+	lw a0, 32(sp)
+	lw a1, 36(sp)
+	call symbol_table_insert
+
+	lw t0, 12(sp)
+	addi t0, t0, 4
+	sw t0, 12(sp)
+
 	# Read the comma between the parameters or a closing paren.
 	mv a0, s1
-	addi a1, sp, 0
+	addi a1, sp, 16
 	call lex_next
 
-	lw t0, 0(sp)
+	lw t0, 16(sp)
 	li t1, TOKEN_COMMA
 	bne t0, t1, .Lcompile_parameters_end
 	# If it is a comma, read the name of the next parameter.
-	addi a1, sp, 12
+	addi a1, sp, 16
 	call lex_next
 	mv s1, a0
 
@@ -1100,13 +1195,13 @@ _compile_parameters:
 	mv s1, a0 # Skip the closing paren.
 
 	# Epilogue.
-	lw ra, 28(sp)
+	lw ra, 44(sp)
-	lw s0, 24(sp)
+	lw s0, 40(sp)
-	addi sp, sp, 32
+	addi sp, sp, 48
 	ret
 
-.type _compile_procedure, @function
+.type compile_procedure, @function
-_compile_procedure:
+compile_procedure:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -1124,17 +1219,19 @@ _compile_procedure:
 	lw a1, 20(sp)
 	call _write_procedure_head
 
-	call _compile_parameters
+	# Save the state of the symbol table before we enter the procedure scope.
-	# Skip all declarations until we find the "begin" keyword, denoting the
+	la t0, symbol_table
-	# beginning of the procedure body.
+	lw t0, (t0)
-.Lcompile_procedure_begin:
+	sw t0, 8(sp)
+
+	call compile_parameters
+	call compile_local_section
+
+	# Skip the "begin" keyword, denoting the beginning of the procedure body.
 	mv a0, s1
-	addi a1, sp, 4
+	addi a1, sp, 12
 	call lex_next
 	mv s1, a0
-	lw t0, 4(sp)
-	li t1, TOKEN_BEGIN
-	bne t0, t1, .Lcompile_procedure_begin
 
 	# Generate the procedure prologue with a predefined stack size.
 	la a0, prologue
@@ -1147,7 +1244,7 @@ _compile_procedure:
 	call _write_out
 
 	# Generate the body of the procedure.
-	call _compile_statements
+	call compile_statements
 	mv s1, a0 # Skip end.
 
 	# Generate the procedure epilogue with a predefined stack size.
@@ -1155,6 +1252,24 @@ _compile_procedure:
 	li a1, EPILOGUE_SIZE
 	call _write_out
 
+	/* DEBUG
+	lw a0, 16(sp)
+	lw a1, 20(sp)
+	call symbol_table_find
+	beqz a0, .x
+*/
+	lw a0, 20(sp)
+	lw a1, 16(sp)
+	call _write_error
+
+	call symbol_table_dump
+	/* DEBUG */
+
+	# Restore the symbol table, removing symbols local to this procedure.
+	la t0, symbol_table
+	lw t1, 8(sp)
+	sw t1, (t0)
+
 	# Epilogue.
 	lw ra, 28(sp)
 	lw s0, 24(sp)
@@ -1162,8 +1277,8 @@ _compile_procedure:
 	ret
 
 # Compiles a goto statement to an uncoditional jump.
-.type _compile_goto, @function
+.type compile_goto, @function
-_compile_goto:
+compile_goto:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -1199,8 +1314,8 @@ _compile_goto:
 	ret
 
 # Rewrites a label to assembly.
-.type _compile_label, @function
+.type compile_label, @function
-_compile_label:
+compile_label:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -1231,8 +1346,8 @@ _compile_label:
 	ret
 
 # Just skips the return keyword and evaluates the return expression.
-.type _compile_return, @function
+.type compile_return, @function
-_compile_return:
+compile_return:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -1252,8 +1367,8 @@ _compile_return:
 	addi sp, sp, 32
 	ret
 
-.type _compile_if, @function
+.type compile_if, @function
-_compile_if:
+compile_if:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -1294,7 +1409,7 @@ _compile_if:
 	li a0, '\n'
 	call _put_char
 
-	call _compile_statements
+	call compile_statements
 	mv s1, a0 # Skip end.
 
 	# Write the label prefix.
@@ -1372,8 +1487,8 @@ _write_procedure_head:
 #
 # Sets a0 to the end of the token finishing the list
 # (should be the "end" token in a valid program).
-.type _compile_statements, @function
+.type compile_statements, @function
-_compile_statements:
+compile_statements:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -1390,7 +1505,7 @@ _compile_statements:
 	beq t0, t1, .Lcompile_statements_end
 
 .Lcompile_statements_body:
-	call _compile_statement
+	call compile_statement
 
 	mv a0, s1
 	addi a1, sp, 0
@@ -1411,8 +1526,8 @@ _compile_statements:
 	ret
 
 # Checks for the type of the current statement and compiles it.
-.type _compile_statement, @function
+.type compile_statement, @function
-_compile_statement:
+compile_statement:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -1442,23 +1557,23 @@ _compile_statement:
 	unimp # Else.
 
 .Lcompile_statement_if:
-	call _compile_if
+	call compile_if
 	j .Lcompile_statement_end
 
 .Lcompile_statement_label:
-	call _compile_label
+	call compile_label
 	j .Lcompile_statement_end
 
 .Lcompile_statement_return:
-	call _compile_return
+	call compile_return
 	j .Lcompile_statement_end
 
 .Lcompile_statement_goto:
-	call _compile_goto
+	call compile_goto
 	j .Lcompile_statement_end
 
 .Lcompile_statement_identifier:
-	call _compile_identifier
+	call compile_identifier
 	j .Lcompile_statement_end
 
 .Lcompile_statement_end:
@@ -1469,8 +1584,8 @@ _compile_statement:
 	ret
 
 # Prints ".section .text" and exits.
-.type _compile_text_section, @function
+.type compile_text_section, @function
-_compile_text_section:
+compile_text_section:
 	# Prologue.
 	addi sp, sp, -16
 	sw ra, 12(sp)
@@ -1487,8 +1602,8 @@ _compile_text_section:
 	addi sp, sp, 16
 	ret
 
-.type _compile_entry_point, @function
+.type compile_entry_point, @function
-_compile_entry_point:
+compile_entry_point:
 	# Prologue.
 	addi sp, sp, -32
 	sw ra, 28(sp)
@@ -1506,7 +1621,7 @@ _compile_entry_point:
 	mv s1, a0 # Skip begin.
 
 	# Generate the body of the procedure.
-	call _compile_statements
+	call compile_statements
 	mv s1, a0 # Skip end.
 
 	la a0, asm_exit
@@ -1519,21 +1634,21 @@ _compile_entry_point:
 	addi sp, sp, 32
 	ret
 
-.type _compile, @function
+.type compile, @function
-_compile:
+compile:
 	# Prologue.
 	addi sp, sp, -16
 	sw ra, 12(sp)
 	sw s0, 8(sp)
 	addi s0, sp, 16
 
-	call _compile_module_declaration
+	call compile_module_declaration
-	call _compile_import
+	call compile_import
-	call _compile_constant_section
+	call compile_constant_section
-	call _compile_variable_section
+	call compile_global_section
-	call _compile_text_section
+	call compile_text_section
-	call _compile_procedure_section
+	call compile_procedure_section
-	call _compile_entry_point
+	call compile_entry_point
 
 	# Epilogue.
 	lw ra, 12(sp)
@@ -1554,7 +1669,7 @@ _start:
 	mv s3, a0
 
 	call symbol_table_build
-	call _compile
+	call compile
 
 	# Call exit.
 	li a0, 0   # Use 0 return code.

boot/stage2.elna

@@ -19,7 +19,11 @@ end
 
 proc _build_binary_expression()
 var
-	loca0, loca4, loca8, loca16, loca20: Word
+	loca0: Word
+	loca4: Word
+	loca8: Word
+	loca16: Word
+	loca20: Word
 	loca12: ^Byte
 	loca24: Bool
 begin
@@ -208,8 +212,12 @@ end
 
 proc _build_expression()
 var
-	loca0, loca20, loca28, loca8: Word
+	loca0: Word
-	loca24, loca4: ^Byte
+	loca20: Word
+	loca28: Word
+	loca8: Word
+	loca24: ^Byte
+	loca4: ^Byte
 begin
 	loca28 := loca84 + 0x30;
 
@@ -340,8 +348,11 @@ end
 
 proc _compile_identifier()
 var
-	loca0, loca16, loca8: Word
+	loca0: Word
-	loca20, loca12: ^Byte
+	loca16: Word
+	loca8: Word
+	loca20: ^Byte
+	loca12: ^Byte
 	loca4: Bool
 begin
 	loca20 := _current();
@@ -375,7 +386,9 @@ end
 
 proc _compile_call(loca84: ^Byte, loca80: Word)
 var
-	loca0, loca4, loca12: Word
+	loca0: Word
+	loca4: Word
+	loca12: Word
 	loca8: ^Byte
 begin
 	loca12 := 0;
@@ -482,7 +495,8 @@ end
 
 proc _read_token()
 var
-	loca0, loca4: Word
+	loca0: Word
+	loca4: Word
 	loca8: ^Byte
 begin
 	loca8 := _current();
@@ -664,7 +678,8 @@ end
 
 proc _compile_constant()
 var
-	loca0, loca4: Word
+	loca0: Word
+	loca4: Word
 	loca8: ^Byte
 begin
 	loca4 := _read_token();
@@ -725,8 +740,11 @@ end
 
 proc _compile_variable()
 var
-	loca28, loca16: ^Byte
+	loca28: ^Byte
-	loca0, loca24, loca20: Word
+	loca16: ^Byte
+	loca0: Word
+	loca24: Word
+	loca20: Word
 begin
 	loca24 := _read_token();
 	loca28 := _current();
@@ -791,8 +809,13 @@ end
 
 proc _compile_procedure()
 var
-	loca0, loca4, loca8, loca12, loca16: Word
+	loca0: Word
-	loca20, loca24: ^Byte
+	loca4: Word
+	loca8: Word
+	loca12: Word
+	loca16: Word
+	loca20: ^Byte
+	loca24: ^Byte
 begin
 	_advance(5);
 	loca16 := _read_token();
@@ -971,7 +994,8 @@ end
 proc _token_compare(loca84: ^Byte, loca80: Word, loca76: ^Byte)
 var
 	loca0: Bool
-	loca4, loca12: Byte
+	loca4: Byte
+	loca12: Byte
 	loca8: Word
 begin
 	.Ltoken_compare_loop;
@@ -1065,7 +1089,10 @@ end
 
 proc _compile_if()
 var
-	loca8, loca12, loca16, loca20: Word
+	loca8: Word
+	loca12: Word
+	loca16: Word
+	loca20: Word
 	loca4: ^Byte
 begin
 	_advance(2);
@@ -1368,7 +1395,8 @@ end
 
 proc _compile()
 var
-	loca0, loca4: Word
+	loca0: Word
+	loca4: Word
 	loca8: Bool
 	loca12: Char
 	loca16: ^Byte

boot/symbol.s

@@ -2,7 +2,9 @@
 # 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/.
 
-.global symbol_table_build, symbol_table_find, symbol_table_make_pointer
+.global symbol_table
+.global symbol_table_build, symbol_table_find, symbol_table_insert, symbol_table_dump
+.global symbol_table_make_pointer, symbol_table_make_parameter, symbol_table_make_local
 
 .include "boot/definitions.inc"
 
@@ -54,14 +56,51 @@ symbol_table: .zero SYMBOL_PRIME
 
 .section .text
 
+# Prints the list of symbols in the table.
+.type symbol_table_dump, @function
+symbol_table_dump:
+	# Prologue.
+	addi sp, sp, -32
+	sw ra, 28(sp)
+	sw s0, 24(sp)
+	addi s0, sp, 32
+
+	sw s1, 20(sp) # Current symbol in the table.
+	sw s2, 16(sp) # Symbol table length.
+
+	la s1, symbol_table
+	lw s2, 0(s1)
+	addi s1, s1, 4 # Advance to the first symbol in the table.
+
+.Lsymbol_table_dump_loop:
+	beqz s2, .Lsymbol_table_dump_end
+
+	# Compare string lengths.
+	lw a0, 4(s1)
+	lw a1, 0(s1)
+	call _write_error
+
+	addi s1, s1, 12
+	addi s2, s2, -1
+	j .Lsymbol_table_dump_loop
+
+.Lsymbol_table_dump_end:
+	lw s1, 20(sp)
+	lw s2, 16(sp)
+
+	# Epilogue.
+	lw ra, 28(sp)
+	lw s0, 24(sp)
+	addi sp, sp, 32
+	ret
+
 # Searches for a symbol by name.
 #
 # Parameters:
-# a0 - Local symbol table or 0.
+# a0 - Length of the symbol to search.
-# a1 - Length of the symbol to search.
+# a1 - Pointer to the symbol name.
-# a2 - Pointer to the symbol name.
 #
-# Sets a0 to the symbol info.
+# Sets a0 to the symbol info pointer or 0 if the symbol has not been found.
 .type symbol_table_find, @function
 symbol_table_find:
 	# Prologue.
@@ -75,8 +114,8 @@ symbol_table_find:
 	sw s3, 12(sp) # Length of the symbol to search.
 	sw s4, 8(sp) # Pointer to the symbol to search.
 
-	mv s3, a1
+	mv s3, a0
-	mv s4, a2
+	mv s4, a1
 
 	la s1, symbol_table
 	lw s2, 0(s1)
@@ -95,7 +134,7 @@ symbol_table_find:
 	beqz a0, .Lsymbol_table_find_continue
 
 	lw a0, 8(s1) # Pointer to the symbol.
-	j .Lsymbol_table_end
+	j .Lsymbol_table_find_end
 
 .Lsymbol_table_find_continue:
 	addi s1, s1, 12
@@ -105,7 +144,7 @@ symbol_table_find:
 .Lsymbol_table_find_not_found:
 	li a0, 0
 
-.Lsymbol_table_end:
+.Lsymbol_table_find_end:
 	lw s1, 20(sp)
 	lw s2, 16(sp)
 	lw s3, 12(sp)
@@ -133,67 +172,108 @@ symbol_table_make_pointer:
 	li a0, 8
 	ret
 
+# Creates a parameter info.
+#
+# Parameters:
+# a0 - Pointer to the parameter type.
+# a1 - Parameter offset.
+# a2 - Output memory.
+#
+# Sets a0 to the size of newly created info object in bytes.
+.type symbol_table_make_parameter, @function
+symbol_table_make_parameter:
+	li t0, INFO_PARAMETER
+	sw t0, 0(a2)
+	sw a0, 4(a2)
+	sw a1, 8(a2)
+
+	li a0, 12
+	ret
+
+# Creates a local variable info.
+#
+# Parameters:
+# a0 - Pointer to the variable type.
+# a1 - Variable stack offset.
+# a2 - Output memory.
+#
+# Sets a0 to the size of newly created info object in bytes.
+.type symbol_table_make_local, @function
+symbol_table_make_local:
+	li t0, INFO_LOCAL
+	sw t0, 0(a2)
+	sw a0, 4(a2)
+	sw a1, 8(a2)
+
+	li a0, 12
+	ret
+
+# Inserts a symbol into the table.
+#
+# Parameters:
+# a0 - Symbol name length.
+# a1 - Symbol name pointer.
+# a2 - Symbol pointer.
+.type symbol_table_insert, @function
+symbol_table_insert:
+	la t0, symbol_table
+
+	lw t1, 0(t0) # Current table length.
+	li t2, 12 # Calculate the offset to the next entry.
+	mul t2, t1, t2
+	addi t2, t2, 4
+	add t2, t0, t2
+
+	sw a0, 0(t2)
+	sw a1, 4(t2)
+	sw a2, 8(t2)
+
+	addi t1, t1, 1 # Save the new length.
+	sw t1, 0(t0)
+
+	ret
+
 # Build the initial symbols.
 #
 # Sets a0 to the pointer to the global symbol table.
 .type symbol_build, @function
 symbol_table_build:
+	# Prologue.
+	addi sp, sp, -16
+	sw ra, 12(sp)
+	sw s0, 8(sp)
+	addi s0, sp, 16
+
 	la a0, symbol_table
 	addi t0, a0, 4
 
-	li t1, 3 # Length of the word "Int".
+	li a0, 3 # Length of the word "Int".
-	sw t1, 0(t0)
+	la a1, symbol_builtin_name_int
-	la t1, symbol_builtin_name_int
+	la a2, symbol_builtin_type_int
-	sw t1, 4(t0)
+	call symbol_table_insert
-	la t1, symbol_builtin_type_int
-	sw t1, 8(t0)
-	lw t1, 0(a0)
-	addi t1, t1, 1
-	sw t1, 0(a0)
-	addi t0, t0, 12
 
-	li t1, 4 # Length of the word "Word".
+	li a0, 4 # Length of the word "Word".
-	sw t1, 0(t0)
+	la a1, symbol_builtin_name_word
-	la t1, symbol_builtin_name_word
+	la a2, symbol_builtin_type_word
-	sw t1, 4(t0)
+	call symbol_table_insert
-	la t1, symbol_builtin_type_word
-	sw t1, 8(t0)
-	lw t1, 0(a0)
-	addi t1, t1, 1
-	sw t1, 0(a0)
-	addi t0, t0, 12
 
-	li t1, 4 # Length of the word "Byte".
+	li a0, 4 # Length of the word "Byte".
-	sw t1, 0(t0)
+	la a1, symbol_builtin_name_byte
-	la t1, symbol_builtin_name_byte
+	la a2, symbol_builtin_type_byte
-	sw t1, 4(t0)
+	call symbol_table_insert
-	la t1, symbol_builtin_type_byte
-	sw t1, 8(t0)
-	lw t1, 0(a0)
-	addi t1, t1, 1
-	sw t1, 0(a0)
-	addi t0, t0, 12
 
-	li t1, 4 # Length of the word "Char".
+	li a0, 4 # Length of the word "Char".
-	sw t1, 0(t0)
+	la a1, symbol_builtin_name_char
-	la t1, symbol_builtin_name_char
+	la a2, symbol_builtin_type_char
-	sw t1, 4(t0)
+	call symbol_table_insert
-	la t1, symbol_builtin_type_char
-	sw t1, 8(t0)
-	lw t1, 0(a0)
-	addi t1, t1, 1
-	sw t1, 0(a0)
-	addi t0, t0, 12
 
-	li t1, 4 # Length of the word "Bool".
+	li a0, 4 # Length of the word "Bool".
-	sw t1, 0(t0)
+	la a1, symbol_builtin_name_bool
-	la t1, symbol_builtin_name_bool
+	la a2, symbol_builtin_type_bool
-	sw t1, 4(t0)
+	call symbol_table_insert
-	la t1, symbol_builtin_type_bool
-	sw t1, 8(t0)
-	lw t1, 0(a0)
-	addi t1, t1, 1
-	sw t1, 0(a0)
-	addi t0, t0, 12
 
+	# Epilogue.
+	lw ra, 12(sp)
+	lw s0, 8(sp)
+	addi sp, sp, 16
 	ret

boot/test.elna

@@ -0,0 +1,14 @@
+program
+
+proc _main(x: Word)
+var loca0: Word
+loca4: Word
+begin
+	loca0 := 0x0a2c3061;
+	loca4 := x;
+	_write_out(@loca4, 4)
+end
+
+begin
+	_main()
+end.