Unify taking an identifier address

boot/common-boot.s

@@ -4,9 +4,9 @@
 
 .global _is_alpha, _is_digit, _is_alnum, _is_upper, _is_lower
 .global _write_s, _read_file, _write_error, _write_c, _write_i, _print_i
-.global _get, _memcmp, _memchr, _memmem, _memcpy
+.global _memcmp, _memchr, _memmem, _memcpy, _mmap
-.global _divide_by_zero_error, _exit, _mmap
+.global _current, _get, _advance, _label_counter
-.global _strings_index, _string_equal
+.global _divide_by_zero_error, _exit, _strings_index, _string_equal
 
 .section .rodata
 
@@ -598,3 +598,33 @@ _mmap:
 	ecall
 
 	ret
+
+# Sets the a0 to the current position in the source text (s1).
+.type _current, @function
+_current:
+	mv a0, s1
+	ret
+
+# Advances the position of the source text.
+#
+# Parameters:
+# a0 - The number of bytes to advance.
+.type _advance, @function
+_advance:
+	add s1, s1, a0
+	ret
+
+# Advances the global label counter by 1 setting a0 to the previous value.
+#
+# Parameters:
+# a0 - If it is 0, resets the counter to 1.
+.type _label_counter, @function
+_label_counter:
+	bnez a0, .Llabel_counter_advance
+	li s2, 0
+
+.Llabel_counter_advance:
+	mv a0, s2
+	addi s2, s2, 1
+
+	ret

boot/stage1.s

@@ -249,31 +249,47 @@ is_local_identifier:
 	addi sp, sp, 16
 	ret
 
-# Checks whether the given identifier is a saved register name, like s1 or s2.
+# Looks for a register that can be used to calculate a symbol address. Writes it
+# as string, like sp or s0 into the provided buffer.
+# 
 # Parameters:
-# a0 - Pointer to the identifier.
+# a0 - Symbol info pointer.
-# a1 - Identifier length.
+# a1 - Output buffer.
 #
-# Sets a0 to 1 if the identifier is a preserved register, otherwise to 0.
+# Sets a0 to the length of register name written or 0.
-.type is_register_identifier, @function
+.type take_address, @function
-is_register_identifier:
+take_address:
-	# Prologue.
+	beqz a0, .Ltake_address_undefined
-	addi sp, sp, -8
+	lw t0, 0(a0)
-	sw ra, 4(sp)
-	sw s0, 0(sp)
-	addi s0, sp, 8
 
-	lbu a0, (a0)
+	li t1, INFO_PARAMETER
-	addi a1, a1, -2
+	beq t0, t1, .Ltake_address_parameter
-	seqz a1, a1
-	addi t0, a0, -'s'
-	seqz t0, t0
-	and a0, a1, t0
 
-	# Epilogue.
+	li t1, INFO_LOCAL
-	lw ra, 4(sp)
+	beq t0, t1, .Ltake_address_local
-	lw s0, 0(sp)
+
-	addi sp, sp, 8
+	j .Ltake_address_undefined
+
+.Ltake_address_parameter:
+	li t0, 0x3073 # s0
+	sh t0, (a1)
+
+	li a0, 2
+
+	j .Ltake_address_end
+
+.Ltake_address_local:
+	li t0, 0x7073 # (sp)
+	sh t0, (a1)
+
+	li a0, 2
+
+	j .Ltake_address_end
+
+.Ltake_address_undefined:
+	li a0, 0
+
+.Ltake_address_end:
 	ret
 
 # Parameters:
@@ -298,18 +314,9 @@ compile_identifier_expression:
 	beqz a0, .Lcompile_identifier_expression_by_name
 	lw t0, 0(a0)
 
-	li t1, INFO_PARAMETER
+	j .Lcompile_identifier_expression_by_address
-	beq t0, t1, .Lcompile_identifier_expression_parameter
-
-	li t1, INFO_LOCAL
-	beq t0, t1, .Lcompile_identifier_expression_local
 
 .Lcompile_identifier_expression_by_name:
-	mv a0, s1
-	lw a1, 20(sp)
-	call is_register_identifier
-	bnez a0, .Lcompile_identifier_expression_saved
-
 	# Global identifier.
 	lw t1, 16(sp)
 	li t0, 0x00202c00 # \0,_
@@ -348,7 +355,7 @@ compile_identifier_expression:
 
 	j .Lcompile_identifier_expression_end
 
-.Lcompile_identifier_expression_parameter:
+.Lcompile_identifier_expression_by_address:
 	lw t1, 16(sp)
 	li t0, 0x00202c00 # \0,_
 	or t0, t0, t1
@@ -363,56 +370,17 @@ compile_identifier_expression:
 	lw a0, 8(a0)
 	call _write_i
 
-	li t0, 0x29307328 # (s0)
+	li a0, '('
-	sw t0, 8(sp)
-	li a0, 4
-	addi a1, sp, 8
-	call _write_s
-	li a0, '\n'
 	call _write_c
 
-	j .Lcompile_identifier_expression_end
-
-.Lcompile_identifier_expression_local:
-	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)
-	li a0, 7
-	addi a1, sp, 4
-	call _write_s
-
 	lw a0, 12(sp)
-	lw a0, 8(a0)
+	addi a1, sp, 4
-	call _write_i
+	call take_address
-
-	li t0, 0x29707328 # (sp)
-	sw t0, 8(sp)
-	li a0, 4
-	addi a1, sp, 8
-	call _write_s
-	li a0, '\n'
-	call _write_c
-
-	j .Lcompile_identifier_expression_end
-
-.Lcompile_identifier_expression_saved:
-	li t0, 0x00202c00 # \0,_
-	lw t1, 16(sp)
-	or t0, t0, t1
-	sw t0, 8(sp)
-	li t0, 0x6120766d # mv a
-	sw t0, 4(sp)
-	li a0, 7
 	addi a1, sp, 4
 	call _write_s
 
-	lw a0, 20(sp)
+	li a0, ')'
-	mv a1, s1
+	call _write_c
-	call _write_s
-
 	li a0, '\n'
 	call _write_c
 
@@ -552,81 +520,36 @@ compile_at_expression:
 	lw a1, 32(sp)
 	call symbol_table_find
 	sw a0, 20(sp)
-	lw t0, 0(a0)
 
-	li t1, INFO_PARAMETER
-	beq t0, t1, .Lcompile_at_expression_parameter
-
-	li t1, INFO_LOCAL
-	beq t0, t1, .Lcompile_at_expression_local
-
-	unimp
-
-.Lcompile_at_expression_local:
-	lw a0, 36(sp)
 	li t0, 0x20 # _
-	sw t0, 16(sp)
+	sb t0, 12(sp)
-	li t0, 0x2c707320 # _sp,
+
-	sw t0, 12(sp)
+	# lw a0, 28(sp)
+	lw a1, 32(sp)
+	addi a1, sp, 13
+	call take_address
+
+	lw t1, 36(sp)
 	li t0, 0x2c006120 # _a\0,
 	sw t0, 8(sp)
-	sb a0, 10(sp)
+	sb t1, 10(sp)
 	li t0, 0x69646461 # addi
 	sw t0, 4(sp)
-	li a0, 13
+	addi a0, a0, 9 # The length returned by take_address + the instruction.
 	addi a1, sp, 4
 	call _write_s
 
+	li a0, ','
+	call _write_c
+	li a0, ' '
+	call _write_c
+
 	lw a0, 20(sp)
 	lw a0, 8(a0)
 	call _write_i
 
 	j .Lcompile_at_expression_end
 
-.Lcompile_at_expression_parameter:
-	lw a0, 36(sp)
-	li t0, 0x20 # _
-	sw t0, 16(sp)
-	li t0, 0x2c307320 # _s0,
-	sw t0, 12(sp)
-	li t0, 0x2c006120 # _a\0,
-	sw t0, 8(sp)
-	sb a0, 10(sp)
-	li t0, 0x69646461 # addi
-	sw t0, 4(sp)
-	li a0, 13
-	addi a1, sp, 4
-	call _write_s
-
-	lw a0, 20(sp)
-	lw a0, 8(a0)
-	call _write_i
-
-	j .Lcompile_at_expression_end
-
-.Lcompile_at_expression_undefined:
-	lw a0, 36(sp)
-	li t0, 0x20 # _
-	sw t0, 16(sp)
-	li t0, 0x2c707320 # _sp,
-	sw t0, 12(sp)
-	li t0, 0x2c006120 # _a\0,
-	sw t0, 8(sp)
-	sb a0, 10(sp)
-	li t0, 0x69646461 # addi
-	sw t0, 4(sp)
-	li a0, 13
-	addi a1, sp, 4
-	call _write_s
-
-	lw a0, 32(sp)
-	lw a1, 28(sp)
-	addi a0, a1, -4 # Skip the "loca" variable prefix.
-	addi a1, a0, 4 # Skip the "loca" variable prefix.
-	call _write_s
-
-	j .Lcompile_at_expression_end
-
 .Lcompile_at_expression_end:
 	li a0, '\n'
 	call _write_c
@@ -658,11 +581,6 @@ compile_designator_expression:
 	call is_local_identifier
 	bnez a0, .Lcompile_designator_expression_local
 
-	lw a0, 20(sp)
-	lw a1, 16(sp)
-	call is_register_identifier
-	bnez a0, .Lcompile_designator_expression_saved
-
 .Lcompile_designator_expression_local:
 	li t0, 0x202c30 # 0,_
 	sw t0, 12(sp)
@@ -688,27 +606,6 @@ compile_designator_expression:
 
 	j .Lcompile_designator_expression_end
 
-.Lcompile_designator_expression_saved:
-	li t0, 0x20766d # mv_
-	sw t0, 12(sp)
-	li a0, 3
-	addi a1, sp, 12
-	call _write_s
-
-	lw a0, 16(sp)
-	lw a1, 20(sp)
-	call _write_s
-
-	li t0, 0x0a # \n
-	sw t0, 12(sp)
-	li t0, 0x3061202c # , a0
-	sw t0, 8(sp)
-	li a0, 5
-	addi a1, sp, 8
-	call _write_s
-
-	j .Lcompile_designator_expression_end
-
 .Lcompile_designator_expression_end:
 	# Epilogue.
 	lw ra, 28(sp)

boot/stage2.elna

@@ -1081,6 +1081,7 @@ proc _compile_label(loca84: Word)
 var
 	loca0: Word
 	loca4: Word
+	loca8: ^Byte
 begin
 	loca0 := _current();
 
@@ -1092,7 +1093,8 @@ begin
 	if loca0 = 0x3b then
 		loca4 := loca4 - 1
 	end;
-	_write_s(loca4, s1);
+	loca8 := _current();
+	_write_s(loca4, loca8);
 
 	_write_c(0x3a);
 	_write_c(0x0a);
@@ -1115,6 +1117,7 @@ var
 	loca12: Word
 	loca16: Word
 	loca20: Word
+	loca24: Word
 begin
 	_advance(2);
 	_skip_spaces();
@@ -1133,8 +1136,9 @@ begin
 	_write_s(4, @loca12);
 	_write_c(0x20);
 
+	loca24 := _label_counter(1);
 	_write_s(4, @loca16);
-	_write_i(s2);
+	_write_i(loca24);
 
 	_write_c(0x0a);
 
@@ -1153,12 +1157,11 @@ begin
 	end;
 
 	_write_s(4, @loca16);
-	_write_i(s2);
+	_write_i(loca24);
 
 	loca12 := 0x0a3a0a3a;
 	_write_s(2, @loca12);
 
-	s2 := s2 + 1;
 	_advance(4)
 end
 
@@ -1445,16 +1448,6 @@ begin
 	.Lcompile_end
 end
 
-proc _current()
-begin
-	return s1
-end
-
-proc _advance(loca84: Word)
-begin
-	s1 := s1 + loca84
-end
-
 proc _front(loca84: ^Word)
 begin
 	return _get(loca84) & 0xff
@@ -1464,7 +1457,7 @@ proc _main()
 begin
 	_read_file(source_code, SOURCE_BUFFER_SIZE);
 
-	s2 := 1
+	_label_counter(0)
 end
 
 begin