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elna/boot/stage9.elna

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(* 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/. *)
(* Stage 8 compiler. *)
(* - Procedure calls in expressions. *)
(* - Comments between (* and *) are supported. These are still single line *)
(* comments and they should be on a separate line. *)
const
symbol_builtin_name_int := "Int";
symbol_builtin_name_word := "Word";
symbol_builtin_name_pointer := "Pointer";
symbol_builtin_name_char := "Char";
symbol_builtin_name_bool := "Bool";
(* Every type info starts with a word describing what type it is. *)
(* PRIMITIVE_TYPE = 1 *)
(* Primitive types have only type size. *)
symbol_builtin_type_int := S(1, 4);
symbol_builtin_type_word := S(1, 4);
symbol_builtin_type_pointer := S(1, 4);
symbol_builtin_type_char := S(1, 1);
symbol_builtin_type_bool := S(1, 1);
(* Info objects start with a word describing its type. *)
(* INFO_TYPE = 1 *)
(* Type info has the type it belongs to. *)
symbol_type_info_int := S(1, @symbol_builtin_type_int);
symbol_type_info_word := S(1, @symbol_builtin_type_word);
symbol_type_info_pointer := S(1, @symbol_builtin_type_pointer);
symbol_type_info_char := S(1, @symbol_builtin_type_char);
symbol_type_info_bool := S(1, @symbol_builtin_type_bool);
var
source_code: Array;
compiler_strings: Array;
symbol_table_global: Array;
symbol_table_local: Array;
classification: Array;
compiler_strings_position: Pointer := @compiler_strings;
compiler_strings_length: Word := 0;
source_code_position: Pointer := @source_code;
(* Calculates and returns the string token length between quotes, including the *)
(* escaping slash characters. *)
(* Parameters: *)
(* a0 - String token pointer. *)
(* Returns the length in a0. *)
proc _string_length();
begin
(* Reset the counter. *)
v0 := 0;
.string_length_loop:
v88 := v88 + 1;
lw t0, 88(sp)
lb t0, (t0)
li t1, '"'
beq t0, t1, .string_length_end
v0 := v0 + 1;
goto .string_length_loop;
.string_length_end:
return v0
end;
(* Adds a string to the global, read-only string storage. *)
(* Parameters: *)
(* a0 - String token. *)
(* Returns the offset from the beginning of the storage to the new string in a0. *)
proc _add_string();
begin
v0 := v88 + 1;
v4 := compiler_strings_length;
.add_string_loop:
lw t0, 0(sp)
lb t1, (t0)
li t2, '"'
beq t1, t2, .add_string_end
la t2, compiler_strings_position
lw t3, (t2)
sb t1, (t3)
addi t3, t3, 1
sw t3, (t2)
addi t0, t0, 1
sw t0, 0(sp)
li t2, '\\'
bne t1, t2, .add_string_increment
goto .add_string_loop;
.add_string_increment:
la t2, compiler_strings_length
lw t4, (t2)
addi t4, t4, 1
sw t4, (t2)
goto .add_string_loop;
.add_string_end:
return v4
end;
(* Reads standard input into a buffer. *)
(* a0 - Buffer pointer. *)
(* a1 - Buffer size. *)
(* Returns the amount of bytes written in a0. *)
proc _read_file();
begin
mv a2, a1
mv a1, a0
(* STDIN. *)
li a0, 0
(* SYS_READ. *)
li a7, 63
ecall
end;
(* Writes to the standard output. *)
(* Parameters: *)
(* a0 - Buffer. *)
(* a1 - Buffer length. *)
proc _write_s();
begin
mv a2, a1
mv a1, a0
(* STDOUT. *)
li a0, 1
(* SYS_WRITE. *)
li a7, 64
ecall
end;
(* Writes a number to a string buffer. *)
(* t0 - Local buffer. *)
(* t1 - Constant 10. *)
(* t2 - Current character. *)
(* t3 - Whether the number is negative. *)
(* Parameters: *)
(* a0 - Whole number. *)
(* a1 - Buffer pointer. *)
(* Sets a0 to the length of the written number. *)
proc _print_i();
begin
li t1, 10
addi t0, s0, -9
li t3, 0
bgez a0, .print_i_digit10
li t3, 1
neg a0, a0
.print_i_digit10:
rem t2, a0, t1
addi t2, t2, '0'
sb t2, 0(t0)
div a0, a0, t1
addi t0, t0, -1
bne zero, a0, .print_i_digit10
beq zero, t3, .print_i_write_call
addi t2, zero, '-'
sb t2, 0(t0)
addi t0, t0, -1
.print_i_write_call:
mv a0, a1
addi a1, t0, 1
sub a2, s0, t0
addi a2, a2, -9
sw a2, 0(sp)
_memcpy();
return v0
end;
(* Writes a number to the standard output. *)
(* Parameters: *)
(* a0 - Whole number. *)
proc _write_i();
begin
v4 := _print_i(v88, @v0);
_write_s(@v0, v4);
end;
(* Writes a character from a0 into the standard output. *)
proc _write_c();
begin
_write_s(@v88, 1);
end;
(* Write null terminated string. *)
(* Parameters: *)
(* a0 - String. *)
proc _write_z();
begin
.write_z_loop:
(* Check for 0 character. *)
lw a0, 88(sp)
lb a0, (a0)
beqz a0, .write_z_end
(* Print a character. *)
_write_c();
(* Advance the input string by one byte. *)
v88 := v88 + 1;
goto .write_z_loop;
.write_z_end:
end;
(* Detects if a0 is an uppercase character. Sets a0 to 1 if so, otherwise to 0. *)
proc _is_upper();
begin
v0 := v88 >= 'A';
v4 := v88 <= 'Z';
return v0 & v4
end;
(* Detects if a0 is an lowercase character. Sets a0 to 1 if so, otherwise to 0. *)
proc _is_lower();
begin
v0 := v88 >= 'a';
v4 := v88 <= 'z';
return v0 & v4
end;
(* Detects if the passed character is a 7-bit alpha character or an underscore. *)
(* Paramters: *)
(* a0 - Tested character. *)
(* Sets a0 to 1 if the character is an alpha character or underscore, sets it to 0 otherwise. *)
proc _is_alpha();
begin
v0 := _is_upper(v88);
v4 := _is_lower(v88);
v8 := v88 = '_';
v12 := v0 or v4;
return v12 or v8
end;
(* Detects whether the passed character is a digit *)
(* (a value between 0 and 9). *)
(* Parameters: *)
(* a0 - Exemined value. *)
(* Sets a0 to 1 if it is a digit, to 0 otherwise. *)
proc _is_digit();
begin
v0 := v88 >= '0';
v4 := v88 <= '9';
return v0 & v4
end;
proc _is_alnum();
begin
v0 := _is_alpha(v88);
v4 := _is_digit(v88);
return v0 or v4
end;
(* Reads the next token. *)
(* Returns token length in a0. *)
proc _read_token();
begin
(* Current token position. *)
v0 := source_code_position;
(* Token length. *)
v4 := 0;
.read_token_loop:
lw t0, 0(sp)
(* Current character. *)
lb t0, (t0)
(* First we try to read a derictive. *)
(* A derictive can contain a dot and characters. *)
li t1, '.'
beq t0, t1, .read_token_next
lw a0, 0(sp)
lb a0, (a0)
_is_alnum();
bnez a0, .read_token_next
goto .read_token_end;
.read_token_next:
(* Advance the source code position and token length. *)
v4 := v4 + 1;
v0 := v0 + 1;
goto .read_token_loop;
.read_token_end:
return v4
end;
(* a0 - First pointer. *)
(* a1 - Second pointer. *)
(* a2 - The length to compare. *)
(* Returns 0 in a0 if memory regions are equal. *)
proc _memcmp();
begin
mv t0, a0
li a0, 0
.memcmp_loop:
beqz a2, .memcmp_end
lbu t1, (t0)
lbu t2, (a1)
sub a0, t1, t2
bnez a0, .memcmp_end
addi t0, t0, 1
addi a1, a1, 1
addi a2, a2, -1
goto .memcmp_loop;
.memcmp_end:
end;
(* Copies memory. *)
(* Parameters: *)
(* a0 - Destination. *)
(* a1 - Source. *)
(* a2 - Size. *)
(* Preserves a0. *)
proc _memcpy();
begin
.memcpy_loop:
beqz a2, .memcpy_end
lbu t1, (a1)
sb t1, (a0)
addi a0, a0, 1
addi a1, a1, 1
addi a2, a2, -1
goto .memcpy_loop
.memcpy_end:
return v88
end;
(* Advances the token stream by a0 bytes. *)
proc _advance_token();
begin
la t0, source_code_position
lw t1, (t0)
add t1, t1, a0
sw t1, (t0)
end;
(* Prints the current token. *)
(* Parameters: *)
(* a0 - Token length. *)
(* Returns a0 unchanged. *)
proc _write_token();
begin
_write_s(source_code_position, v88);
return v88
end;
(* Prints and skips a line. *)
proc _compile_line();
begin
.compile_line_loop:
la a0, source_code_position
lw a1, (a0)
lb t0, (a1)
li t1, '\n'
beq t0, t1, .compile_line_end
(* Print a character. *)
lw a0, (a1)
_write_c();
(* Advance the input string by one byte. *)
_advance_token(1);
goto .compile_line_loop;
.compile_line_end:
_write_c('\n');
_advance_token(1);
end;
proc _compile_integer_literal();
begin
_write_z("\tli t0, \0");
v0 := _read_token();
_write_token(v0);
_advance_token(v0);
_write_c('\n');
end;
proc _compile_character_literal();
begin
_write_z("\tli t0, \0");
_write_c('\'');
_advance_token(1);
la t0, source_code_position
lw t0, (t0)
lb a0, (t0)
li t1, '\\'
bne a0, t1, .compile_character_literal_end
_write_c('\\');
_advance_token(1);
.compile_character_literal_end:
la t0, source_code_position
lw t0, (t0)
lb a0, (t0)
_write_c();
_write_c('\'');
_write_c('\n');
_advance_token(2);
end;
proc _compile_variable_expression();
begin
_compile_designator();
_write_z("\tlw t0, (t0)\n\0");
end;
proc _compile_address_expression();
begin
(* Skip the "@" sign. *)
_advance_token(1);
_compile_designator();
end;
proc _compile_negate_expression();
begin
(* Skip the "-" sign. *)
_advance_token(1);
_compile_term();
_write_z("\tneg t0, t0\n\0");
end;
proc _compile_not_expression();
begin
(* Skip the "~" sign. *)
_advance_token(1);
_compile_term();
_write_z("\tnot t0, t0\n\0");
end;
proc _compile_string_literal();
begin
v0 := _string_length(source_code_position);
v4 := _add_string(source_code_position);
_advance_token(v0 + 2);
_write_z("\tla t0, strings\n\0");
_write_z("\tli t1, \0");
_write_i(v4);
_write_c('\n');
_write_z("\tadd t0, t0, t1\n\0");
end;
proc _compile_term();
begin
la t0, source_code_position
lw t0, (t0)
lb a0, (t0)
sw a0, 0(sp)
li t1, '\''
beq a0, t1, .compile_term_character_literal
li t1, '@'
beq a0, t1, .compile_term_address
li t1, '-'
beq a0, t1, .compile_term_negation
li t1, '~'
beq a0, t1, .compile_term_not
li t1, '"'
beq a0, t1, .compile_term_string_literal
li t1, '_'
beq a0, t1, .compile_term_call
_is_digit(v0);
bnez a0, .compile_term_integer_literal
goto .compile_term_variable;
.compile_term_character_literal:
_compile_character_literal();
goto .compile_term_end;
.compile_term_integer_literal:
_compile_integer_literal();
goto .compile_term_end;
.compile_term_address:
_compile_address_expression();
goto .compile_term_end;
.compile_term_negation:
_compile_negate_expression();
goto .compile_term_end;
.compile_term_not:
_compile_not_expression();
goto .compile_term_end;
.compile_term_string_literal:
_compile_string_literal();
goto .compile_term_end;
.compile_term_call:
_compile_call();
_write_z("\nmv t0, a0\n\0");
goto .compile_term_end;
.compile_term_variable:
_compile_variable_expression();
goto .compile_term_end;
.compile_term_end:
end;
proc _compile_binary_rhs();
begin
(* Skip the whitespace after the binary operator. *)
_advance_token(1);
_compile_term();
(* Load the left expression from the stack; *)
_write_z("\tlw t1, 24(sp)\n\0");
end;
proc _compile_expression();
begin
_compile_term();
la t0, source_code_position
lw t0, (t0)
lb a0, (t0)
li t1, ' '
bne a0, t1, .compile_expression_end
(* It is a binary expression. *)
(* Save the value of the left expression on the stack. *)
_write_z("sw t0, 24(sp)\n\0");
(* Skip surrounding whitespace in front of the operator. *)
_advance_token(1);
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
li t1, '+'
beq t0, t1, .compile_expression_add
li t1, '*'
beq t0, t1, .compile_expression_mul
li t1, '&'
beq t0, t1, .compile_expression_and
li t1, 'o'
beq t0, t1, .compile_expression_or
li t1, 'x'
beq t0, t1, .compile_expression_xor
li t1, '='
beq t0, t1, .compile_expression_equals
li t1, '<'
beq t0, t1, .compile_expression_less
li t1, '>'
beq t0, t1, .compile_expression_greater
(* Unknown binary operator. *)
unimp
.compile_expression_add:
_advance_token(1);
_compile_binary_rhs();
(* Execute the operation. *)
_write_z("add t0, t0, t1\n\0");
goto .compile_expression_end;
.compile_expression_mul:
_advance_token(1);
_compile_binary_rhs();
(* Execute the operation. *)
_write_z("\tmul t0, t0, t1\n\0");
goto .compile_expression_end;
.compile_expression_and:
_advance_token(1);
_compile_binary_rhs();
(* Execute the operation. *)
_write_z("\tand t0, t0, t1\n\0");
goto .compile_expression_end;
.compile_expression_or:
_advance_token(2);
_compile_binary_rhs();
(* Execute the operation. *)
_write_z("or t0, t0, t1\n\0");
goto .compile_expression_end;
.compile_expression_xor:
_advance_token(3);
_compile_binary_rhs();
(* Execute the operation. *)
_write_z("xor t0, t0, t1\n\0");
goto .compile_expression_end;
.compile_expression_equals:
_advance_token(1);
_compile_binary_rhs();
(* Execute the operation. *)
_write_z("xor t0, t0, t1\nseqz t0, t0\n\0");
goto .compile_expression_end;
.compile_expression_less:
_advance_token(1);
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
li t1, '>'
beq t0, t1, .compile_expression_not_equal
li t1, '='
beq t0, t1, .compile_expression_less_equal
_compile_binary_rhs();
(* Execute the operation. *)
_write_z("slt t0, t0, t1\n\0");
goto .compile_expression_end;
.compile_expression_not_equal:
_advance_token(1);
_compile_binary_rhs();
(* Execute the operation. *)
_write_z("\txor t0, t0, t1\nsnez t0, t0\n\0");
goto .compile_expression_end;
.compile_expression_less_equal:
_advance_token(1);
_compile_binary_rhs();
(* Execute the operation. *)
_write_z("\tslt t0, t0, t1\nxori t0, t0, 1\n\0");
goto .compile_expression_end;
.compile_expression_greater:
_advance_token(1);
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
li t1, '='
beq t0, t1, .compile_expression_greater_equal
_compile_binary_rhs();
(* Execute the operation. *)
_write_z("\tslt t0, t1, t0\n\0");
goto .compile_expression_end;
.compile_expression_greater_equal:
_advance_token(1);
_compile_binary_rhs();
(* Execute the operation. *)
_write_z("\tslt t0, t1, t0\nxori t0, t0, 1\n\0");
goto .compile_expression_end;
.compile_expression_end:
end;
proc _compile_call();
begin
(* Stack variables: *)
(* v0 - Procedure name length. *)
(* v4 - Procedure name pointer. *)
(* v8 - Argument count. *)
v0 := _read_token();
v4 := source_code_position;
v8 := 0;
(* Skip the identifier and left paren. *)
_advance_token(v0 + 1);
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
li t1, ')'
beq t0, t1, .compile_call_finalize
.compile_call_loop:
_compile_expression();
(* Save the argument on the stack. *)
_write_z("\tsw t0, \0");
(* Calculate the stack offset: 116 - (4 * argument_counter) *)
v12 := v8 * 4;
v12 := 116 + -v12;
_write_i(v12);
_write_z("(sp)\n\0");
(* Add one to the argument counter. *)
v8 := v8 + 1;
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
li t1, ','
bne t0, t1, .compile_call_finalize
_advance_token(2);
goto .compile_call_loop;
.compile_call_finalize:
(* Load the argument from the stack. *)
lw t0, 8(sp)
beqz t0, .compile_call_end
(* Decrement the argument counter. *)
v8 := v8 + -1;
_write_z("\tlw a\0");
_write_i(v8);
_write_z(", \0");
(* Calculate the stack offset: 116 - (4 * argument_counter) *)
v12 := v8 * 4;
v12 := 116 + -v12;
_write_i(v12);
_write_z("(sp)\n\0");
goto .compile_call_finalize;
.compile_call_end:
_write_z("\tcall \0");
_write_s(v4, v0);
(* Skip the right paren. *)
_advance_token(1);
end;
proc _compile_goto();
begin
_advance_token(5);
v0 := _read_token();
_write_z("\tj \0");
_write_token(v0);
_advance_token();
end;
proc _compile_local_designator();
begin
(* Skip "v" in the local variable name. *)
_advance_token(1);
_write_z("\t addi t0, sp, \0");
(* Read local variable stack offset and save it. *)
v0 := _read_token();
_write_token(v0);
_advance_token(v0);
_write_c('\n');
end;
proc _compile_global_designator();
begin
_write_z("\tla t0, \0");
v0 := _read_token();
_write_token(v0);
_advance_token(v0);
_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. *)
_write_z("\tsw t0, 20(sp)\n\0");
(* Skip the assignment sign (:=) with surrounding whitespaces. *)
_advance_token(4);
(* Compile the assignment. *)
_compile_expression();
_write_z("\tlw t1, 20(sp)\nsw t0, (t1)\n\0");
end;
proc _compile_return_statement();
begin
(* Skip "return" keyword and whitespace after it. *)
_advance_token(7);
_compile_expression();
_write_z("mv a0, t0\n\0");
end;
proc _compile_statement();
begin
(* This is a call if the statement starts with an underscore. *)
la t0, source_code_position
lw t0, (t0)
(* First character after alignment tab. *)
addi t0, t0, 1
lb t0, (t0)
li t1, '_'
beq t0, t1, .compile_statement_call
li t1, 'g'
beq t0, t1, .compile_statement_goto
li t1, 'v'
beq t0, t1, .compile_statement_assignment
(* keyword_ret contains "\tret", so it's 4 bytes long. *)
_memcmp(source_code_position, "\treturn", 7);
beqz a0, .compile_statement_return
_compile_line();
goto .compile_statement_end;
.compile_statement_call:
_advance_token(1);
_compile_call();
goto .compile_statement_semicolon;
.compile_statement_goto:
_advance_token(1);
_compile_goto();
goto .compile_statement_semicolon;
.compile_statement_assignment:
_advance_token(1);
_compile_assignment();
goto .compile_statement_semicolon;
.compile_statement_return:
_advance_token(1);
_compile_return_statement();
_write_c('\n');
goto .compile_statement_end;
.compile_statement_semicolon:
_advance_token(2);
_write_c('\n');
.compile_statement_end:
end;
proc _compile_procedure_body();
begin
.compile_procedure_body_loop:
_skip_empty_lines();
(* 3 is "end" length. *)
_memcmp(source_code_position, "end", 3);
beqz a0, .compile_procedure_body_epilogue
_compile_statement();
goto .compile_procedure_body_loop;
.compile_procedure_body_epilogue:
end;
(* Writes a regster name to the standard output. *)
(* Parameters: *)
(* a0 - Register character. *)
(* a1 - Register number. *)
proc _write_register();
begin
_write_c(v88);
v84 := v84 + '0';
_write_c(v84);
end;
proc _compile_procedure_prologue();
begin
_write_z("\taddi sp, sp, -128\n\tsw ra, 124(sp)\n\tsw s0, 120(sp)\n\taddi s0, sp, 128\n\0");
v0 := 0;
.compile_procedure_prologue_loop:
_write_z("\tsw a\0");
_write_i(v0);
_write_z(", \0");
(* Calculate the stack offset: 88 - (4 * parameter_counter) *)
v4 := v0 * 4;
v4 := 88 + -v4;
_write_i(v4);
_write_z("(sp)\n\0");
v0 := v0 + 1;
lw a0, 0(sp)
li t0, 8
bne a0, t0, .compile_procedure_prologue_loop
end;
proc _compile_procedure();
begin
(* Skip "proc ". *)
_advance_token(5);
(* Save the procedure name length. *)
v0 := _read_token();
(* Write .type _procedure_name, @function. *)
_write_z(".type \0");
_write_token(v0);
_write_z(", @function\n\0");
(* Write procedure label, _procedure_name: *)
_write_token(v0);
_write_z(":\n\0");
(* Skip the function name and trailing parens, semicolon, "begin" and newline. *)
_advance_token(v0 + 10);
_compile_procedure_prologue();
_compile_procedure_body();
(* Write the epilogue. *)
_write_z("\tlw ra, 124(sp)\n\tlw s0, 120(sp)\n\taddi sp, sp, 128\n\tret\n\0");
(* Skip the "end" keyword, semicolon and newline. *)
_advance_token(5);
end;
proc _skip_newlines();
begin
(* Skip newlines. *)
la t0, source_code_position
lw t1, (t0)
.skip_newlines_loop:
lb t2, (t1)
li t3, '\n'
bne t2, t3, .skip_newlines_end
beqz t2, .skip_newlines_end
addi t1, t1, 1
sw t1, (t0)
goto .skip_newlines_loop;
.skip_newlines_end:
end;
(* Prints and skips a line. *)
proc _skip_comment();
begin
la t0, source_code_position
lw t1, (t0)
.skip_comment_loop:
(* Check for newline character. *)
lb t2, (t1)
li t3, '\n'
beq t2, t3, .skip_comment_end
(* Advance the input string by one byte. *)
addi t1, t1, 1
sw t1, (t0)
goto .skip_comment_loop;
.skip_comment_end:
(* Skip the newline. *)
addi t1, t1, 1
sw t1, (t0)
end;
(* Skip newlines and comments. *)
proc _skip_empty_lines();
begin
.skip_empty_lines_rerun:
la t0, source_code_position
lw t0, (t0)
sw t0, 0(sp)
.skip_empty_lines_loop:
lw t2, 0(sp)
lb t0, (t2)
li t1, '#'
beq t0, t1, .skip_empty_lines_comment
li t1, '\n'
beq t0, t1, .skip_empty_lines_newline
li t1, '\t'
beq t0, t1, .skip_empty_lines_tab
li t1, '('
bne t0, t1, .skip_empty_lines_end
addi t2, t2, 1
lb t0, (t2)
li t1, '*'
beq t0, t1, .skip_empty_lines_comment
goto .skip_empty_lines_end;
.skip_empty_lines_comment:
la t0, source_code_position
lw t1, 0(sp)
sw t1, (t0)
_skip_comment();
goto .skip_empty_lines_rerun;
.skip_empty_lines_newline:
la t0, source_code_position
lw t1, 0(sp)
addi t1, t1, 1
sw t1, (t0)
goto .skip_empty_lines_rerun;
.skip_empty_lines_tab:
v0 := v0 + 1;
goto .skip_empty_lines_loop
.skip_empty_lines_end:
end;
proc _compile_global_initializer();
begin
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
li t1, '"'
beq t0, t1, .compile_global_initializer_string
li t1, 'S'
beq t0, t1, .compile_global_initializer_record
li t1, '@'
beq t0, t1, .compile_global_initializer_pointer
la a0, source_code_position
lw a0, (a0)
lb a0, (a0)
_is_digit();
bnez a0, .compile_global_initializer_number
unimp
.compile_global_initializer_pointer:
(* Skip @. *)
_advance_token(1);
_write_z("\n\t.word \0");
v0 := _read_token();
_write_token(v0);
_advance_token(v0);
goto .compile_global_initializer_end;
.compile_global_initializer_number:
_write_z("\n\t.word \0");
v0 := _read_token();
_write_token(v0);
_advance_token(1);
goto .compile_global_initializer_end;
.compile_global_initializer_record:
(* Skip "S(". *)
_advance_token(2);
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
li t1, ')'
beq t0, t1, .compile_global_initializer_closing
.compile_global_initializer_loop:
_compile_global_initializer();
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
li t1, ')'
beq t0, t1, .compile_global_initializer_closing
(* Skip comma and whitespace after it. *)
_advance_token(2);
goto .compile_global_initializer_loop;
.compile_global_initializer_closing:
(* Skip ")" *)
_advance_token(1);
goto .compile_global_initializer_end;
.compile_global_initializer_string:
_write_z("\n\t.word strings + \0");
v4 := _string_length(source_code_position);
_add_string(source_code_position);
_write_i();
(* Skip the quoted string. *)
_advance_token(v4 + 2);
goto .compile_global_initializer_end;
.compile_global_initializer_end:
end;
proc _compile_constant_declaration();
begin
_read_token();
sw a0, 0(sp)
_write_z(".type \0");
_write_token(v0);
_write_z(", @object\n\0");
_write_token(v0);
_write_c(':');
(* Skip the constant name with assignment sign and surrounding whitespaces. *)
_advance_token(v0 + 4);
_compile_global_initializer();
(* Skip semicolon and newline. *)
_advance_token(2);
_write_c('\n');
end;
proc _compile_const_part();
begin
_skip_empty_lines();
_memcmp(source_code_position, "const\0", 5);
bnez a0, .compile_const_part_end
(* Skip "const" with the newline after it. *)
_advance_token(6);
_write_z(".section .rodata # Compiled from const section.\n\n\0");
.compile_const_part_loop:
_skip_empty_lines();
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
(* If the character at the line beginning is not indentation, *)
(* it is probably the next code section. *)
li t1, '\t'
bne t0, t1, .compile_const_part_end
_advance_token(1);
_compile_constant_declaration();
goto .compile_const_part_loop;
.compile_const_part_end:
end;
proc _compile_variable_declaration();
begin
v0 := _read_token();
_write_z(".type \0");
_write_token(v0);
_write_z(", @object\n\0");
_write_token(v0);
_write_c(':');
(* Skip the variable name and colon with space before the type. *)
_advance_token(v0 + 2);
(* Skip the type name. *)
v4 := _read_token();
_advance_token(v4);
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
li t1, ' '
beq t0, t1, .compile_variable_declaration_initializer
(* Else we assume this is a zeroed 81920 bytes big array. *)
_write_z(" .zero 81920\0");
goto .compile_variable_declaration_finalize;
.compile_variable_declaration_initializer:
(* Skip the assignment sign with surrounding whitespaces. *)
_advance_token(4);
_compile_global_initializer();
goto .compile_variable_declaration_finalize;
.compile_variable_declaration_finalize:
(* Skip semicolon and newline. *)
_advance_token(2);
_write_c('\n');
end;
proc _compile_var_part();
begin
_memcmp(source_code_position, "var\0", 3);
bnez a0, .compile_var_part_end
(* Skip "var" and newline. *)
_advance_token(4);
_write_z(".section .data\n\0");
.compile_var_part_loop:
_skip_empty_lines();
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
li t1, '\t'
beq t0, t1, .compile_var_part_declaration
goto .compile_var_part_end;
.compile_var_part_declaration:
_advance_token(1);
_compile_variable_declaration();
goto .compile_var_part_loop;
.compile_var_part_end:
end;
(* Process the source code and print the generated code. *)
proc _compile_module();
begin
_compile_const_part();
_skip_empty_lines();
_compile_var_part();
_write_z(".section .text\n\0");
.compile_module_loop:
_skip_empty_lines();
la t0, source_code_position
lw t0, (t0)
lb t0, (t0)
beqz t0, .compile_module_end
(* 5 is "proc " length. Space is needed to distinguish from "procedure". *)
_memcmp(source_code_position, "proc ", 5);
beqz a0, .compile_module_procedure
(* Not a known token, exit. *)
goto .compile_module_end;
.compile_module_procedure:
_compile_procedure();
goto .compile_module_loop;
.compile_module_end:
end;
proc _compile();
begin
_write_z(".globl _start\n\n\0");
_compile_module();
_write_z(".section .rodata\n.type strings, @object\nstrings: .ascii \0");
_write_c('"');
v0 := @compiler_strings;
v4 := compiler_strings_position;
.compile_loop:
lw t0, 0(sp)
lw t1, 4(sp)
bge t0, t1, .compile_end
lb a0, (t0)
addi t0, t0, 1
sw t0, 0(sp)
_write_c();
j .compile_loop
.compile_end:
_write_c('"');
_write_c('\n');
end;
(* Terminates the program. a0 contains the return code. *)
(* Parameters: *)
(* a0 - Status code. *)
proc _exit();
begin
li a7, 93 # SYS_EXIT
ecall
end;
(* Inserts a symbol into the table. *)
(* Parameters: *)
(* a0 - Symbol pointer. *)
(* a1 - Symbol name length. *)
(* a2 - Symbol name pointer. *)
(* a3 - Symbol table. *)
proc _symbol_table_enter();
begin
(* The first word in the symbol table is its length, get it. *)
lw a0, 76(sp)
lw a0, (a0)
sw a0, 0(sp)
(* Calculate the offset for the new symbol. *)
v4 := v0 * 4;
v4 := v4 + 4;
v4 := v76 + 4;
_memcpy(v4, @v80, 12);
(* Increment the symbol table length. *)
v0 := v0 + 1;
lw t0, 0(sp)
lw t1, 76(sp)
sw t0, (t1)
end;
proc _symbol_table_build();
begin
_symbol_table_enter(@symbol_type_info_int, 3, symbol_builtin_name_int, @symbol_table_global);
_symbol_table_enter(@symbol_type_info_word, 4, symbol_builtin_name_word, @symbol_table_global);
_symbol_table_enter(@symbol_type_info_pointer, 7, symbol_builtin_name_pointer, @symbol_table_global);
_symbol_table_enter(@symbol_type_info_char, 4, symbol_builtin_name_char, @symbol_table_global);
_symbol_table_enter(@symbol_type_info_bool, 4, symbol_builtin_name_bool, @symbol_table_global);
end;
(* Classification table assigns each possible character to a group (class). All *)
(* characters of the same group a handled equivalently. *)
(* Classification: *)
(* TransitionClass = ( *)
(* transitionClassInvalid = 1, *)
(* transitionClassDigit = 2, *)
(* transitionClassAlpha = 3, *)
(* transitionClassSpace = 4, *)
(* transitionClassColon = 5, *)
(* transitionClassEquals = 6, *)
(* transitionClassLeftParen = 7, *)
(* transitionClassRightParen = 8, *)
(* transitionClassAsterisk = 9, *)
(* transitionClassUnderscore = 10, *)
(* transitionClassSingle = 11, *)
(* transitionClassHex = 12, *)
(* transitionClassZero = 13, *)
(* transitionClassX = 14, *)
(* transitionClassEof = 15, *)
(* transitionClassDot = 16, *)
(* transitionClassMinus = 17, *)
(* transitionClassSingleQuote = 18, *)
(* transitionClassDoubleQuote = 19, *)
(* transitionClassGreater = 20, *)
(* transitionClassLess = 21, *)
(* transitionClassOther = 22 *)
(* ); *)
(* TransitionState = ( *)
(* transitionStateStart = 1, *)
(* transitionStateColon = 2, *)
(* transitionStateIdentifier = 3, *)
(* transitionStateDecimal = 4, *)
(* transitionStateGreater = 5, *)
(* transitionStateMinus = 6, *)
(* transitionStateLeftParen = 7, *)
(* transitionStateLess = 8, *)
(* transitionStateDot = 9, *)
(* transitionStateComment = 10, *)
(* transitionStateClosingComment = 11, *)
(* transitionStateCharacter = 12, *)
(* transitionStateString = 13, *)
(* transitionStateLeadingZero = 14, *)
(* transitionStateDecimalSuffix = 15, *)
(* transitionStateEnd = 16 *)
(* ); *)
(* Transition = record *)
(* action: TransitionAction; *)
(* next_state: TransitionState *)
(* end; *)
(* TransitionAction = ( *)
(* none = 1, *)
(* accumulate = 2, *)
(* skip = 3, *)
(* single = 4, *)
(* eof = 5, *)
(* finalize = 6, *)
(* composite = 7, *)
(* key_id = 8, *)
(* integer = 9, *)
(* delimited = 10 *)
(* ); *)
(* Assigns some value to at array index. *)
(* Parameters: *)
(* a0 - Array pointer. *)
(* a1 - Index (word offset into the array). *)
(* a2 - Data to assign. *)
proc _assign_at();
begin
v0 := v84 + -1;
v0 := v0 * 4;
v0 := v88 + v0;
lw t0, 0(sp)
lw t1, 80(sp)
sw t1, (t0)
end;
proc _initialize_classification();
begin
_assign_at(@classification, 1, 15);
_assign_at(@classification, 2, 1);
_assign_at(@classification, 3, 1);
_assign_at(@classification, 4, 1);
_assign_at(@classification, 5, 1);
_assign_at(@classification, 6, 1);
_assign_at(@classification, 7, 1);
_assign_at(@classification, 8, 1);
_assign_at(@classification, 9, 1);
_assign_at(@classification, 10, 4);
_assign_at(@classification, 11, 4);
_assign_at(@classification, 12, 1);
_assign_at(@classification, 13, 1);
_assign_at(@classification, 14, 4);
_assign_at(@classification, 15, 1);
_assign_at(@classification, 16, 1);
_assign_at(@classification, 17, 1);
_assign_at(@classification, 18, 1);
_assign_at(@classification, 19, 1);
_assign_at(@classification, 20, 1);
_assign_at(@classification, 21, 1);
_assign_at(@classification, 22, 1);
_assign_at(@classification, 23, 1);
_assign_at(@classification, 24, 1);
_assign_at(@classification, 25, 1);
_assign_at(@classification, 26, 1);
_assign_at(@classification, 27, 1);
_assign_at(@classification, 28, 1);
_assign_at(@classification, 29, 1);
_assign_at(@classification, 30, 1);
_assign_at(@classification, 31, 1);
_assign_at(@classification, 32, 1);
_assign_at(@classification, 33, 4);
_assign_at(@classification, 34, 11);
_assign_at(@classification, 35, 19);
_assign_at(@classification, 36, 22);
_assign_at(@classification, 37, 22);
_assign_at(@classification, 38, 11);
_assign_at(@classification, 39, 11);
_assign_at(@classification, 40, 18);
_assign_at(@classification, 41, 7);
_assign_at(@classification, 42, 8);
_assign_at(@classification, 43, 9);
_assign_at(@classification, 44, 11);
_assign_at(@classification, 45, 11);
_assign_at(@classification, 46, 17);
_assign_at(@classification, 47, 16);
_assign_at(@classification, 48, 11);
_assign_at(@classification, 49, 13);
_assign_at(@classification, 50, 2);
_assign_at(@classification, 51, 2);
_assign_at(@classification, 52, 2);
_assign_at(@classification, 53, 2);
_assign_at(@classification, 54, 2);
_assign_at(@classification, 55, 2);
_assign_at(@classification, 56, 2);
_assign_at(@classification, 57, 2);
_assign_at(@classification, 58, 2);
_assign_at(@classification, 59, 5);
_assign_at(@classification, 60, 11);
_assign_at(@classification, 61, 21);
_assign_at(@classification, 62, 6);
_assign_at(@classification, 63, 20);
_assign_at(@classification, 64, 22);
_assign_at(@classification, 65, 11);
_assign_at(@classification, 66, 3);
_assign_at(@classification, 67, 3);
_assign_at(@classification, 68, 3);
_assign_at(@classification, 69, 3);
_assign_at(@classification, 70, 3);
_assign_at(@classification, 71, 3);
_assign_at(@classification, 72, 3);
_assign_at(@classification, 73, 3);
_assign_at(@classification, 74, 3);
_assign_at(@classification, 75, 3);
_assign_at(@classification, 76, 3);
_assign_at(@classification, 77, 3);
_assign_at(@classification, 78, 3);
_assign_at(@classification, 79, 3);
_assign_at(@classification, 80, 3);
_assign_at(@classification, 81, 3);
_assign_at(@classification, 82, 3);
_assign_at(@classification, 83, 3);
_assign_at(@classification, 84, 3);
_assign_at(@classification, 85, 3);
_assign_at(@classification, 86, 3);
_assign_at(@classification, 87, 3);
_assign_at(@classification, 88, 3);
_assign_at(@classification, 89, 3);
_assign_at(@classification, 90, 3);
_assign_at(@classification, 91, 3);
_assign_at(@classification, 92, 11);
_assign_at(@classification, 93, 22);
_assign_at(@classification, 94, 11);
_assign_at(@classification, 95, 11);
_assign_at(@classification, 96, 10);
_assign_at(@classification, 97, 22);
_assign_at(@classification, 98, 12);
_assign_at(@classification, 99, 12);
_assign_at(@classification, 100, 12);
_assign_at(@classification, 101, 12);
_assign_at(@classification, 102, 12);
_assign_at(@classification, 103, 12);
_assign_at(@classification, 104, 3);
_assign_at(@classification, 105, 3);
_assign_at(@classification, 106, 3);
_assign_at(@classification, 107, 3);
_assign_at(@classification, 108, 3);
_assign_at(@classification, 109, 3);
_assign_at(@classification, 110, 3);
_assign_at(@classification, 111, 3);
_assign_at(@classification, 112, 3);
_assign_at(@classification, 113, 3);
_assign_at(@classification, 114, 3);
_assign_at(@classification, 115, 3);
_assign_at(@classification, 116, 3);
_assign_at(@classification, 117, 3);
_assign_at(@classification, 118, 3);
_assign_at(@classification, 119, 3);
_assign_at(@classification, 120, 3);
_assign_at(@classification, 121, 14);
_assign_at(@classification, 122, 3);
_assign_at(@classification, 123, 3);
_assign_at(@classification, 124, 22);
_assign_at(@classification, 125, 11);
_assign_at(@classification, 126, 22);
_assign_at(@classification, 127, 11);
_assign_at(@classification, 128, 1);
v0 := 129;
(* Set the remaining 129 - 256 bytes to transitionClassOther. *)
.initialize_classification_loop:
_assign_at(@classification, v0, 22);
v0 := v0 + 1;
lw t0, 0(sp)
li t1, 257
blt t0, t1, .initialize_classification_loop
end;
(* Parameters: *)
(* a0 - Current state (first index into transitions table). *)
(* a1 - Transition (second index into transitions table).. *)
(* a2 - Action to assign. *)
(* a3 - Next state to assign. *)
proc _set_transition();
begin
(* Transitions start at offset in classification array. Save the transitions start in v0. *)
v0 := @classification + 256
(* Each state is 8 bytes long (2 words: action and next state). *)
(* There are 16 transition classes, so a transition 8 * 16 = 128 bytes long. *)
v4 := v88 + -1;
v4 := v4 * 128;
v8 := v84 + -1;
v8 := v8 * 8;
v12 := v0 + v4;
v12 := v12 + v8;
lw t0, 12(sp)
lw t1, 80(sp)
lw t2, 76(sp)
sw t1, (t0)
addi t0, t0, 4
sw t2, (t0)
end;
(* Parameters: *)
(* a0 - Current state (Transition state enumeration). *)
(* a1 - Default action (Callback). *)
(* a2 - Next state (Transition state enumeration). *)
proc _set_default_transition();
begin
_set_transition(v88, 1, v84, v80);
_set_transition(v88, 2, v84, v80);
_set_transition(v88, 3, v84, v80);
_set_transition(v88, 4, v84, v80);
_set_transition(v88, 5, v84, v80);
_set_transition(v88, 6, v84, v80);
_set_transition(v88, 7, v84, v80);
_set_transition(v88, 8, v84, v80);
_set_transition(v88, 9, v84, v80);
_set_transition(v88, 10, v84, v80);
_set_transition(v88, 11, v84, v80);
_set_transition(v88, 12, v84, v80);
_set_transition(v88, 13, v84, v80);
_set_transition(v88, 14, v84, v80);
_set_transition(v88, 15, v84, v80);
_set_transition(v88, 16, v84, v80);
_set_transition(v88, 17, v84, v80);
_set_transition(v88, 18, v84, v80);
_set_transition(v88, 19, v84, v80);
_set_transition(v88, 20, v84, v80);
_set_transition(v88, 21, v84, v80);
_set_transition(v88, 22, v84, v80);
end;
(* The transition table describes transitions from one state to another, given *)
(* a symbol (character class). *)
(* The table has m rows and n columns, where m is the amount of states and n is *)
(* the amount of classes. So given the current state and a classified character *)
(* the table can be used to look up the next state. *)
(* Each cell is a word long. *)
(* - The least significant byte of the word is a row number (beginning with 0). *)
(* It specifies the target state. "ff" means that this is an end state and no *)
(* transition is possible. *)
(* - The next byte is the action that should be performed when transitioning. *)
(* For the meaning of actions see labels in the lex_next function, which *)
(* handles each action. *)
proc _initialize_transitions();
begin
(* Start state. *)
_set_transition(1, 1, 1, 16);
_set_transition(1, 2, 2, 4);
_set_transition(1, 3, 2, 3);
_set_transition(1, 4, 3, 1);
_set_transition(1, 5, 2, 5);
_set_transition(1, 6, 4, 16);
_set_transition(1, 7, 2, 7);
_set_transition(1, 8, 4, 16);
_set_transition(1, 9, 4, 16);
_set_transition(1, 10, 2, 3);
_set_transition(1, 11, 4, 16);
_set_transition(1, 12, 2, 3);
_set_transition(1, 13, 2, 14);
_set_transition(1, 14, 2, 3);
_set_transition(1, 15, 5, 16);
_set_transition(1, 16, 2, 9);
_set_transition(1, 17, 2, 6);
_set_transition(1, 18, 2, 12);
_set_transition(1, 19, 2, 13);
_set_transition(1, 20, 2, 5);
_set_transition(1, 21, 2, 8);
_set_transition(1, 22, 1, 16);
(* Colon state. *)
_set_default_transition(2, 6, 16);
_set_transition(2, 6, 7, 16);
(* Identifier state. *)
_set_default_transition(3, 8, 16);
_set_transition(3, 2, 2, 3);
_set_transition(3, 3, 2, 3);
_set_transition(3, 10, 2, 3);
_set_transition(3, 12, 2, 3);
_set_transition(3, 13, 2, 3);
_set_transition(3, 14, 2, 3);
(* Decimal state. *)
_set_default_transition(4, 9, 16);
_set_transition(4, 2, 2, 4);
_set_transition(4, 3, 2, 15);
_set_transition(4, 10, 1, 16);
_set_transition(4, 12, 2, 15);
_set_transition(4, 13, 2, 4);
_set_transition(4, 14, 2, 15);
(* Greater state. *)
_set_default_transition(5, 6, 16);
_set_transition(5, 6, 7, 16);
(* Minus state. *)
_set_default_transition(6, 6, 16);
_set_transition(6, 20, 7, 16);
(* Left paren state. *)
_set_default_transition(7, 6, 16);
_set_transition(7, 9, 2, 10);
(* Less state. *)
_set_default_transition(8, 6, 16);
_set_transition(8, 6, 7, 16);
_set_transition(8, 20, 7, 16);
(* Hexadecimal after 0x. *)
_set_default_transition(9, 6, 16);
_set_transition(9, 16, 7, 16);
(* Comment. *)
_set_default_transition(10, 2, 10);
_set_transition(10, 9, 2, 11);
_set_transition(10, 15, 1, 16);
(* Closing comment. *)
_set_default_transition(11, 2, 10);
_set_transition(11, 1, 1, 16);
_set_transition(11, 8, 10, 16);
_set_transition(11, 9, 2, 11);
_set_transition(11, 15, 1, 16);
(* Character. *)
_set_default_transition(12, 2, 12);
_set_transition(12, 1, 1, 16);
_set_transition(12, 15, 1, 16);
_set_transition(12, 18, 10, 16);
(* String. *)
_set_default_transition(13, 2, 13);
_set_transition(13, 1, 1, 16);
_set_transition(13, 15, 1, 16);
_set_transition(13, 19, 10, 16);
(* Leading zero. *)
_set_default_transition(14, 9, 16);
_set_transition(14, 2, 1, 16);
_set_transition(14, 3, 1, 16);
_set_transition(14, 10, 1, 16);
_set_transition(14, 12, 1, 16);
_set_transition(14, 13, 1, 16);
_set_transition(14, 14, 1, 16);
(* Digit with a character suffix. *)
_set_default_transition(15, 9, 16);
_set_transition(15, 3, 1, 16);
_set_transition(15, 2, 1, 16);
_set_transition(15, 12, 1, 16);
_set_transition(15, 13, 1, 16);
_set_transition(15, 14, 1, 16);
end;
proc _lexer_get_state();
begin
(* Lexer state is saved after the transition tables. The offset is 256 + 16 * 22. *)
v0 := @classification;
v4 := 16 * 22;
v0 := v0 + 256;
return v0 + v4
end;
(* Gets pointer to the current source text. *)
proc _lexer_get_current();
begin
_lexer_get_state();
sw a0, 0(sp)
return v0 + 4
end;
(* Resets the lexer state for reading the next token. *)
proc _lexer_reset();
begin
(* Transition start state is 1. *)
_lexer_get_state();
li t0, 1
sw t0, (a0)
sw a0, 0(sp)
(* Text pointer to the beginning of the currently read token. *)
_lexer_get_current();
la t0, source_code_position
lw t0, (t0)
sw t0, (a0)
(* Initial length of the token is 0. *)
addi t0, t0, 4
sw zero, (t0)
end;
(* One time lexer initialization. *)
proc _lexer_initialize();
begin
_initialize_classification();
_initialize_transitions();
end;
(* Entry point. *)
proc _start();
begin
_lexer_initialize();
_symbol_table_build();
(* Read the source from the standard input. *)
(* Second argument is buffer size. Modifying update the source_code definition. *)
_read_file(@source_code, 81920);
_compile();
_exit(0);
end;