summaryrefslogtreecommitdiff
path: root/boot/stage4.elna
diff options
context:
space:
mode:
Diffstat (limited to 'boot/stage4.elna')
-rw-r--r--boot/stage4.elna238
1 files changed, 199 insertions, 39 deletions
diff --git a/boot/stage4.elna b/boot/stage4.elna
index d6bbb9d..1d98c3a 100644
--- a/boot/stage4.elna
+++ b/boot/stage4.elna
@@ -2,14 +2,13 @@
# 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.
-# - 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.
+# - Taking value of local and global variables. Variables that doesn't begin
+# with "v" are considered global.
+# - Simple variable assignment, e.g. v0 := 5 or v0 := global_variable;
+# 7 words on the stack, 28 - 56, are reversed for procedure arguments (caller side).
+# - Take address unary operation "@".
.section .rodata
@@ -38,10 +37,10 @@ keyword_begin: .ascii "begin"
keyword_var: .ascii "var"
.type asm_prologue, @object
-asm_prologue: .string "\taddi sp, sp, -32\n\tsw ra, 28(sp)\n\tsw s0, 24(sp)\n\taddi s0, sp, 32\n"
+asm_prologue: .string "\taddi sp, sp, -64\n\tsw ra, 60(sp)\n\tsw s0, 56(sp)\n\taddi s0, sp, 64\n"
.type asm_epilogue, @object
-asm_epilogue: .string "\tlw ra, 28(sp)\n\tlw s0, 24(sp)\n\taddi sp, sp, 32\n\tret\n"
+asm_epilogue: .string "\tlw ra, 60(sp)\n\tlw s0, 56(sp)\n\taddi sp, sp, 64\n\tret\n"
.type asm_type_directive, @object
asm_type_directive: .string ".type "
@@ -64,23 +63,26 @@ 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
-asm_mv: .string "mv "
+.type asm_addi, @object
+asm_addi: .string "\taddi "
.type asm_t0, @object
asm_t0: .string "t0"
-.type asm_a0, @object
-asm_a0: .string "a0"
+.type asm_t1, @object
+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 +259,7 @@ begin
_is_upper();
sw a0, 4(sp)
- _is_lower(v00);
+ _is_lower(v0);
lw t0, 0(sp)
xori t1, t0, '_'
@@ -292,7 +294,7 @@ begin
_is_alpha();
sw a0, 0(sp)
- _is_digit(v04);
+ _is_digit(v4);
lw a1, 0(sp)
or a0, a0, a1
@@ -491,7 +493,7 @@ begin
la a0, asm_li
_write_z();
- la a0, asm_a0
+ la a0, asm_t0
_write_z();
la a0, asm_comma
@@ -509,7 +511,7 @@ begin
la a0, asm_li
_write_z();
- la a0, asm_a0
+ la a0, asm_t0
_write_z();
la a0, asm_comma
@@ -542,43 +544,51 @@ 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);
- _read_token();
- _write_token();
- _advance_token();
-
- la a0, asm_sp
+ _write_c('(');
+ la a0, asm_t0
_write_z();
+ _write_c(')');
_write_c('\n');
end;
+proc _compile_address_expression();
+begin
+ # Skip the "@" sign.
+ _advance_token(1);
+ _compile_designator();
+
+end;
+
proc _compile_expression();
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'
- beq a0, t1, .compile_expression_variable
+ li t1, '@'
+ beq a0, t1, .compile_expression_address
- _is_digit();
+ _is_digit(v0);
bnez a0, .compile_expression_integer_literal
- goto .compile_expression_end;
+ goto .compile_expression_variable;
.compile_expression_character_literal:
_compile_character_literal();
@@ -588,9 +598,13 @@ begin
_compile_integer_literal();
goto .compile_expression_end;
+.compile_expression_address:
+ _compile_address_expression();
+ goto .compile_expression_end;
+
.compile_expression_variable:
_compile_variable_expression();
- goto .compile_expression_end;;
+ goto .compile_expression_end;
.compile_expression_end:
end;
@@ -628,22 +642,24 @@ begin
la a0, asm_sw
_write_z();
- la a0, asm_a0
+ la a0, asm_t0
_write_z();
la a0, asm_comma
_write_z();
- # Calculate the stack offset: 20 - (4 * argument_counter)
+ # Calculate the stack offset: 52 - (4 * argument_counter)
lw t0, 8(sp)
li t1, 4
mul t0, t0, t1
- li t1, 20
+ li t1, 52
sub a0, t1, t0
_write_i();
+ _write_c('(')
la a0, asm_sp
_write_z();
+ _write_c(')')
_write_c('\n');
@@ -683,17 +699,19 @@ begin
la a0, asm_comma
_write_z();
- # Calculate the stack offset: 20 - (4 * argument_counter)
+ # Calculate the stack offset: 52 - (4 * argument_counter)
lw t0, 8(sp)
li t1, 4
mul t0, t0, t1
- li t1, 20
+ li t1, 52
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 +720,7 @@ begin
la a0, asm_call
_write_z();
- _write_s(v04, v00);
+ _write_s(v4, v0);
# Skip the right paren.
_advance_token(1);
@@ -718,8 +736,141 @@ 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();
@@ -737,6 +888,9 @@ 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 +906,12 @@ 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 +949,13 @@ 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();
generated by cgit v1.2.3 (git 2.26.2) at 2026-06-27 08:03:14 +0000