diff --git a/Rakefile b/Rakefile index 32157d0..a772900 100644 --- a/Rakefile +++ b/Rakefile @@ -6,7 +6,9 @@ require 'open3' require 'rake/clean' -STAGES = Dir.glob('boot/stage*.elna').collect { |stage| File.basename stage, '.elna' }.sort +STAGES = Dir.glob('boot/stage*.elna') + .collect { |stage| File.basename stage, '.elna' } + .sort { |a, b| a.delete_prefix('stage').to_i <=> b.delete_prefix('stage').to_i } CLEAN.include 'build/boot', 'build/valid' @@ -39,17 +41,9 @@ end desc 'Convert previous stage language into the current stage language' task :convert do - File.open('boot/stage9.elna', 'w') do |current_stage| - File.readlines('boot/stage8.elna').each do |line| - comment_match = /^(\s*)#(.*)/.match line - - if comment_match.nil? - current_stage << line - elsif comment_match[2].empty? - current_stage << "\n" - else - current_stage << "#{comment_match[1]}(* #{comment_match[2].strip} *)\n" - end + File.open('boot/stage10.elna', 'w') do |current_stage| + File.readlines('boot/stage9.elna').each do |line| + current_stage << line end end end diff --git a/boot/stage10.elna b/boot/stage10.elna new file mode 100644 index 0000000..da96da7 --- /dev/null +++ b/boot/stage10.elna @@ -0,0 +1,1722 @@ +(* 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 10 compiler. *) + +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; + label_counter: 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; + + if _load_byte(v88) <> '"' then + v0 := v0 + 1; + goto .string_length_loop; + 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: + if _load_byte(v0) <> '"' then + v8 := _load_byte(v0); + _store_byte(v8, compiler_strings_position); + _store_word(compiler_strings_position + 1, @compiler_strings_position); + v0 := v0 + 1; + + if v8 <> '\\' then + _store_word(compiler_strings_length + 1, @compiler_strings_length); + end; + goto .add_string_loop; + 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 + _syscall(0, v88, v84, 0, 0, 0, 63); +end; + +(* Writes to the standard output. *) + +(* Parameters: *) +(* a0 - Buffer. *) +(* a1 - Buffer length. *) +proc _write_s(); +begin + _syscall(1, v88, v84, 0, 0, 0, 64); +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 + (* Check for 0 character. *) + v0 := _load_byte(v88); + + if v0 <> 0 then + (* Print a character. *) + _write_c(v0); + + (* Advance the input string by one byte. *) + _write_z(v88 + 1); + 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: + (* Current character. *) + v8 := _load_byte(v0); + + (* First we try to read a derictive. *) + (* A derictive can contain a dot and characters. *) + v12 := v8 = '.'; + v16 := _is_alnum(v8); + + if v12 or v16 then + (* Advance the source code position and token length. *) + v4 := v4 + 1; + v0 := v0 + 1; + + goto .read_token_loop; + 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 + v8 := 0; + +.memcmp_loop: + if v80 <> 0 then + v0 := _load_byte(v88); + v4 := _load_byte(v84); + v8 := v0 + -v4; + + v88 := v88 + 1; + v84 := v84 + 1; + v80 := v80 + -1; + + if v8 = 0 then + goto .memcmp_loop; + end; + end; + + return v8 +end; + +(* Copies memory. *) + +(* Parameters: *) +(* a0 - Destination. *) +(* a1 - Source. *) +(* a2 - Size. *) + +(* Preserves a0. *) +proc _memcpy(); +begin +.memcpy_loop: + if v80 <> 0 then + v0 := _load_byte(v84); + _store_byte(v0, v88); + + v88 := v88 + 1; + v84 := v84 + 1; + v80 := v80 + -1; + goto .memcpy_loop; + end; + + return v88 +end; + +(* Advances the token stream by a0 bytes. *) +proc _advance_token(); +begin + _store_word(source_code_position + v88, @source_code_position); +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: + v0 := _load_byte(source_code_position); + + if v0 <> '\n' then + (* Print a character. *) + _write_c(v0); + + (* Advance the input string by one byte. *) + _advance_token(1); + + goto .compile_line_loop; + end; + +.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); + + v0 := _load_byte(source_code_position); + if v0 = '\\' then + _write_c('\\'); + _advance_token(1); + end; + + v0 := _load_byte(source_code_position); + _write_c(v0); + + _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 + v0 := _load_byte(source_code_position); + + if v0 = '\'' then + _compile_character_literal(); + end; + if v0 = '@' then + _compile_address_expression(); + end; + if v0 = '-' then + _compile_negate_expression(); + end; + if v0 = '~' then + _compile_not_expression(); + end; + if v0 = '"' then + _compile_string_literal(); + end; + if v0 = '_' then + _compile_call(); + _write_z("\nmv t0, a0\n\0"); + end; + if _is_digit(v0) = 1 then + _compile_integer_literal(); + end; + if _is_lower(v0) = 1 then + _compile_variable_expression(); + 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(); + v0 := _load_byte(source_code_position); + + if v0 <> ' ' then + goto .compile_expression_end; + 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); + v0 := _load_byte(source_code_position); + + if v0 = '+' then + _advance_token(1); + _compile_binary_rhs(); + + (* Execute the operation. *) + _write_z("add t0, t0, t1\n\0"); + + goto .compile_expression_end; + end; + if v0 = '*' then + _advance_token(1); + _compile_binary_rhs(); + + (* Execute the operation. *) + _write_z("\tmul t0, t0, t1\n\0"); + + goto .compile_expression_end; + end; + if v0 = '&' then + _advance_token(1); + _compile_binary_rhs(); + + (* Execute the operation. *) + _write_z("\tand t0, t0, t1\n\0"); + + goto .compile_expression_end; + end; + if v0 = 'o' then + _advance_token(2); + _compile_binary_rhs(); + + (* Execute the operation. *) + _write_z("or t0, t0, t1\n\0"); + + goto .compile_expression_end; + end; + if v0 = 'x' then + _advance_token(3); + _compile_binary_rhs(); + + (* Execute the operation. *) + _write_z("xor t0, t0, t1\n\0"); + + goto .compile_expression_end; + end; + if v0 = '=' then + _advance_token(1); + _compile_binary_rhs(); + + (* Execute the operation. *) + _write_z("xor t0, t0, t1\nseqz t0, t0\n\0"); + + goto .compile_expression_end; + end; + if v0 = '<' then + _advance_token(1); + v0 := _load_byte(source_code_position); + + if v0 = '>' then + _advance_token(1); + _compile_binary_rhs(); + + (* Execute the operation. *) + _write_z("\txor t0, t0, t1\nsnez t0, t0\n\0"); + + goto .compile_expression_end; + end; + if v0 = '=' then + _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; + end; + _compile_binary_rhs(); + + (* Execute the operation. *) + _write_z("slt t0, t0, t1\n\0"); + + goto .compile_expression_end; + end; + if v0 = '>' then + _advance_token(1); + v0 := _load_byte(source_code_position); + if v0 = '=' then + li t1, '=' + _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; + end; + _compile_binary_rhs(); + + (* Execute the operation. *) + _write_z("\tslt t0, t1, t0\n\0"); + + goto .compile_expression_end; + 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); + v12 := _load_byte(source_code_position); + + if v12 = ')' then + goto .compile_call_finalize + end; +.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; + + v12 := _load_byte(source_code_position); + + if v12 <> ',' then + goto .compile_call_finalize; + end; + _advance_token(2); + goto .compile_call_loop; + +.compile_call_finalize: + (* Load the argument from the stack. *) + if v8 <> 0 then + (* 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; + end; + +.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 + if _load_byte(source_code_position) = 'v' then + _compile_local_designator(); + else + _compile_global_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; + +(* Writes a label, .Ln, where n is a unique number. *) + +(* Parameters: *) +(* a0 - Label counter. *) +proc _write_label(); +begin + _write_z(".L\0"); + _write_i(v88); +end; + +proc _compile_if(); +begin + (* Skip "if ". *) + _advance_token(3); + (* Compile condition. *) + _compile_expression(); + (* Skip " then" with newline. *) + _advance_token(6); + + (* v0 is the label after the if statement. *) + v0 := label_counter; + _store_word(label_counter + 1, @label_counter); + (* v4 is the label in front of the next elsif condition or end. *) + v4 := label_counter; + _store_word(label_counter + 1, @label_counter); + + _write_z("\tbeqz t0, \0"); + _write_label(v4); + _write_c('\n'); + + _compile_procedure_body(); + + _write_z("\tj \0"); + _write_label(v0); + _write_c('\n'); + + _write_label(v4); + _write_z(":\n\0"); + + _memcmp(source_code_position, "end", 3); + beqz a0, .compile_if_end + + _memcmp(source_code_position, "else", 3); + beqz a0, .compile_if_else + +.compile_if_else: + (* Skip "else" and newline. *) + _advance_token(5); + _compile_procedure_body(); + +.compile_if_end: + (* Skip "end". *) + _advance_token(3); + + _write_label(v0); + _write_z(":\n\0"); +end; + +proc _compile_statement(); +begin + _skip_spaces(); + v0 := _load_byte(source_code_position); + + (* This is a call if the statement starts with an underscore. *) + if v0 = '_' then + _compile_call(); + goto .compile_statement_semicolon; + end; + if v0 = 'g' then + _compile_goto(); + goto .compile_statement_semicolon; + end; + if v0 = 'v' then + _compile_assignment(); + goto .compile_statement_semicolon; + end; + if v0 = 'i' then + _compile_if(); + goto .compile_statement_semicolon; + end; + if _memcmp(source_code_position, "return", 6) = 0 then + _compile_return_statement(); + _write_c('\n'); + + goto .compile_statement_end; + end; + _compile_line(); + 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(); + _skip_spaces(); + + v0 := _memcmp(source_code_position, "end", 3) = 0; + v4 := _memcmp(source_code_position, "else", 4) = 0; + v4 := v0 or v4; + + if v4 = 0 then + _compile_statement(); + goto .compile_procedure_body_loop; + end; +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; + if v0 <> 8 then + goto .compile_procedure_prologue_loop; + end; +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_spaces(); +begin + v0 := _load_byte(source_code_position); + if v0 = '\t' then + _advance_token(1); + _skip_spaces(); + end; +end; + +(* Prints and skips a line. *) +proc _skip_comment(); +begin +.skip_comment_loop: + v0 := _load_byte(source_code_position); + + (* Check for newline character. *) + if v0 <> '\n' then + (* Advance the input string by one byte. *) + _advance_token(1); + + goto .skip_comment_loop; + end; + (* Skip the newline. *) + _advance_token(1); +end; + +(* Skip newlines and comments. *) +proc _skip_empty_lines(); +begin +.skip_empty_lines_rerun: + v0 := source_code_position; + +.skip_empty_lines_loop: + v4 := _load_byte(v0); + + if v4 = '\n' then + goto .skip_empty_lines_newline; + end; + if v4 = '\t' then + goto .skip_empty_lines_tab; + end; + if v4 <> '(' then + goto .skip_empty_lines_end; + end; + v4 := v0 + 1; + + if _load_byte(v4) = '*' then + goto .skip_empty_lines_comment + end; + goto .skip_empty_lines_end; + +.skip_empty_lines_comment: + _store_word(v0, @source_code_position); + _skip_comment(); + goto .skip_empty_lines_rerun; + +.skip_empty_lines_newline: + _store_word(v0 + 1, @source_code_position); + 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 + v0 := _load_byte(source_code_position); + + if v0 = '"' then + _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; + end; + if v0 = 'S' then + (* Skip "S(". *) + _advance_token(2); + + if _load_byte(source_code_position) = ')' then + goto .compile_global_initializer_closing; + end; + goto .compile_global_initializer_loop; + end; + if v0 = '@' then + (* Skip @. *) + _advance_token(1); + _write_z("\n\t.word \0"); + v0 := _read_token(); + _write_token(v0); + _advance_token(v0); + + goto .compile_global_initializer_end; + end; + if _is_digit(v0) = 1 then + _write_z("\n\t.word \0"); + v0 := _read_token(); + _write_token(v0); + _advance_token(1); + + goto .compile_global_initializer_end; + end; + unimp + +.compile_global_initializer_loop: + _compile_global_initializer(); + + if _load_byte(source_code_position) <> ')' then + (* Skip comma and whitespace after it. *) + _advance_token(2); + + goto .compile_global_initializer_loop; + end; + +.compile_global_initializer_closing: + (* Skip ")" *) + _advance_token(1); + + goto .compile_global_initializer_end; + +.compile_global_initializer_end: +end; + +proc _compile_constant_declaration(); +begin + v0 := _read_token(); + + _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(); + + if _memcmp(source_code_position, "const\0", 5) <> 0 then + goto .compile_const_part_end; + 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(); + + (* If the character at the line beginning is not indentation, *) + (* it is probably the next code section. *) + if _load_byte(source_code_position) = '\t' then + _advance_token(1); + + _compile_constant_declaration(); + goto .compile_const_part_loop; + end; + +.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); + + if _load_byte(source_code_position) <> ' ' then + (* Else we assume this is a zeroed 81920 bytes big array. *) + _write_z(" .zero 81920\0"); + else + (* Skip the assignment sign with surrounding whitespaces. *) + _advance_token(4); + _compile_global_initializer(); + end; + + (* Skip semicolon and newline. *) + _advance_token(2); + _write_c('\n'); +end; + +proc _compile_var_part(); +begin + if _memcmp(source_code_position, "var\0", 3) <> 0 then + goto .compile_var_part_end; + end; + (* Skip "var" and newline. *) + _advance_token(4); + _write_z(".section .data\n\0"); + +.compile_var_part_loop: + _skip_empty_lines(); + v0 := _load_byte(source_code_position); + + if v0 = '\t' then + _advance_token(1); + _compile_variable_declaration(); + goto .compile_var_part_loop; + end; + +.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\n\0"); + _write_z(".type _syscall, @function\n_syscall:\n\tmv a7, a6\n\tecall\n\tret\n\n\0"); + _write_z(".type _load_byte, @function\n_load_byte:\n\tlb a0, (a0)\nret\n\n\0"); + _write_z(".type _load_word, @function\n_load_word:\n\tlw a0, (a0)\nret\n\n\0"); + _write_z(".type _store_byte, @function\n_store_byte:\n\tsb a0, (a1)\nret\n\n\0"); + _write_z(".type _store_word, @function\n_store_word:\n\tsw a0, (a1)\nret\n\n\0"); + +.compile_module_loop: + _skip_empty_lines(); + + if _load_byte(source_code_position) <> 0 then + (* 5 is "proc " length. Space is needed to distinguish from "procedure". *) + if _memcmp(source_code_position, "proc ", 5) = 0 then + _compile_procedure(); + goto .compile_module_loop; + end; + end; +.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 + + v8 := _load_byte(v0); + v0 := v0 + 1; + _write_c(v8); + + 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 + _syscall(0, 0, 0, 0, 0, 0, 93); +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. *) + v0 := _load_word(v76); + + (* 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; + _store_word(v0, v76); +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; + + _store_word(v80, v0); +end; + +proc _create_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. *) +.create_classification_loop: + _assign_at(@classification, v0, 22); + v0 := v0 + 1; + + if v0 < 257 then + goto .create_classification_loop; + end; +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; + + _store_word(v80, v12); + v12 := v12 + 4; + _store_word(v76, v12); +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 _create_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 + return _lexer_get_state() + 4; +end; + +(* Resets the lexer state for reading the next token. *) +proc _lexer_reset(); +begin + (* Transition start state is 1. *) + v0 := _lexer_get_state(); + _store_word(1, v4); + + (* Text pointer to the beginning of the currently read token. *) + v4 := _lexer_get_current(); + _store_word(source_code_position, v4); + + (* Initial length of the token is 0. *) + _store_word(0, source_code_position + 4); +end; + +(* One time lexer initialization. *) +proc _lexer_initialize(); +begin + _create_classification(); + _create_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; diff --git a/boot/stage8.elna b/boot/stage8.elna index 6243634..75c24d7 100644 --- a/boot/stage8.elna +++ b/boot/stage8.elna @@ -7,6 +7,10 @@ # - Procedure calls in expressions. # - Comments between (* and *) are supported. These are still single line # comments and they should be on a separate line. +# - _syscall builtin. _syscall takes 7 arguments, +# the 7th argument gets stored in a7 before invoking ecall. +# Other arguments are saved in a0 through a5. +# - New intrinsics: _load_byte, _load_word, _store_byte, _store_word. const symbol_builtin_name_int := "Int"; symbol_builtin_name_word := "Word"; @@ -1403,7 +1407,13 @@ begin _skip_empty_lines(); _compile_var_part(); - _write_z(".section .text\n\0"); + _write_z(".section .text\n\n\0"); + _write_z(".type _syscall, @function\n_syscall:\n\tmv a7, a6\n\tecall\n\tret\n\n\0"); + _write_z(".type _load_byte, @function\n_load_byte:\n\tlb a0, (a0)\nret\n\n\0"); + _write_z(".type _load_word, @function\n_load_word:\n\tlw a0, (a0)\nret\n\n\0"); + _write_z(".type _store_byte, @function\n_store_byte:\n\tsb a0, (a1)\nret\n\n\0"); + _write_z(".type _store_word, @function\n_store_word:\n\tsw a0, (a1)\nret\n\n\0"); + .compile_module_loop: _skip_empty_lines(); diff --git a/boot/stage9.elna b/boot/stage9.elna index ebeb467..9f5e4d5 100644 --- a/boot/stage9.elna +++ b/boot/stage9.elna @@ -2,11 +2,12 @@ (* 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. *) +(* Stage 9 compiler. *) (* - Procedure calls in expressions. *) (* - Comments between (* and *) are supported. These are still single line *) (* comments and they should be on a separate line. *) +(* - if-else statements. *) const symbol_builtin_name_int := "Int"; symbol_builtin_name_word := "Word"; @@ -45,6 +46,7 @@ var compiler_strings_position: Pointer := @compiler_strings; compiler_strings_length: Word := 0; + label_counter: Word := 0; source_code_position: Pointer := @source_code; (* Calculates and returns the string token length between quotes, including the *) @@ -93,16 +95,12 @@ begin 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) + v8 := _load_byte(v0); + _store_byte(v8, compiler_strings_position); + _store_word(compiler_strings_position + 1, @compiler_strings_position); + v0 := v0 + 1; + lb t1, 8(sp) li t2, '\\' bne t1, t2, .add_string_increment @@ -127,13 +125,7 @@ end; (* 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 + _syscall(0, v88, v84, 0, 0, 0, 63); end; (* Writes to the standard output. *) @@ -143,13 +135,7 @@ end; (* a1 - Buffer length. *) proc _write_s(); begin - mv a2, a1 - mv a1, a0 - (* STDOUT. *) - li a0, 1 - (* SYS_WRITE. *) - li a7, 64 - ecall + _syscall(1, v88, v84, 0, 0, 0, 64); end; (* Writes a number to a string buffer. *) @@ -317,9 +303,8 @@ begin li t1, '.' beq t0, t1, .read_token_next - lw a0, 0(sp) - lb a0, (a0) - _is_alnum(); + v8 := _load_byte(v0); + _is_alnum(v8); bnez a0, .read_token_next goto .read_token_end; @@ -464,10 +449,8 @@ begin _advance_token(1); .compile_character_literal_end: - la t0, source_code_position - lw t0, (t0) - lb a0, (t0) - _write_c(); + v0 := _load_byte(source_code_position); + _write_c(v0); _write_c('\''); _write_c('\n'); @@ -523,10 +506,8 @@ end; proc _compile_term(); begin - la t0, source_code_position - lw t0, (t0) - lb a0, (t0) - sw a0, 0(sp) + v0 := _load_byte(source_code_position); + lb a0, 0(sp) li t1, '\'' beq a0, t1, .compile_term_character_literal @@ -925,13 +906,72 @@ begin _write_z("mv a0, t0\n\0"); end; +(* Writes a label, .Ln, where n is a unique number. *) + +(* Parameters: *) +(* a0 - Label counter. *) +proc _write_label(); +begin + _write_z(".L\0"); + _write_i(v88); +end; + +proc _compile_if(); +begin + (* Skip "if ". *) + _advance_token(3); + (* Compile condition. *) + _compile_expression(); + (* Skip " then" with newline. *) + _advance_token(6); + + (* v0 is the label after the if statement. *) + v0 := label_counter; + _store_word(label_counter + 1, @label_counter); + (* v4 is the label in front of the next elsif condition or end. *) + v4 := label_counter; + _store_word(label_counter + 1, @label_counter); + + _write_z("\tbeqz t0, \0"); + _write_label(v4); + _write_c('\n'); + + _compile_procedure_body(); + + _write_z("\tj \0"); + _write_label(v0); + _write_c('\n'); + + _write_label(v4); + _write_z(":\n\0"); + + _memcmp(source_code_position, "end", 3); + beqz a0, .compile_if_end + + _memcmp(source_code_position, "else", 3); + beqz a0, .compile_if_else + +.compile_if_else: + (* Skip "else" and newline. *) + _advance_token(5); + _compile_procedure_body(); + +.compile_if_end: + (* Skip "end". *) + _advance_token(3); + + _write_label(v0); + _write_z(":\n\0"); +end; + proc _compile_statement(); begin + _skip_spaces(); (* 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 + (* addi t0, t0, 1 *) lb t0, (t0) li t1, '_' @@ -943,33 +983,42 @@ begin li t1, 'v' beq t0, t1, .compile_statement_assignment + li t1, 'i' + beq t0, t1, .compile_statement_if + (* keyword_ret contains "\tret", so it's 4 bytes long. *) - _memcmp(source_code_position, "\treturn", 7); + _memcmp(source_code_position, "return", 6); beqz a0, .compile_statement_return _compile_line(); goto .compile_statement_end; .compile_statement_call: - _advance_token(1); + (* _advance_token(1); *) _compile_call(); goto .compile_statement_semicolon; .compile_statement_goto: - _advance_token(1); + (* _advance_token(1); *) _compile_goto(); goto .compile_statement_semicolon; .compile_statement_assignment: - _advance_token(1); + (* _advance_token(1); *) _compile_assignment(); goto .compile_statement_semicolon; +.compile_statement_if: + (* _advance_token(1); *) + _compile_if(); + + goto .compile_statement_semicolon; + .compile_statement_return: - _advance_token(1); + (* _advance_token(1); *) _compile_return_statement(); _write_c('\n'); @@ -986,10 +1035,12 @@ proc _compile_procedure_body(); begin .compile_procedure_body_loop: _skip_empty_lines(); + _skip_spaces(); - (* 3 is "end" length. *) _memcmp(source_code_position, "end", 3); + beqz a0, .compile_procedure_body_epilogue + _memcmp(source_code_position, "else", 4); beqz a0, .compile_procedure_body_epilogue _compile_statement(); @@ -1065,24 +1116,24 @@ begin _advance_token(5); end; -proc _skip_newlines(); +proc _skip_spaces(); begin (* Skip newlines. *) la t0, source_code_position lw t1, (t0) -.skip_newlines_loop: +.skip_spaces_loop: lb t2, (t1) - li t3, '\n' - bne t2, t3, .skip_newlines_end - beqz t2, .skip_newlines_end + li t3, '\t' + bne t2, t3, .skip_spaces_end + beqz t2, .skip_spaces_end addi t1, t1, 1 sw t1, (t0) - goto .skip_newlines_loop; + goto .skip_spaces_loop; -.skip_newlines_end: +.skip_spaces_end: end; (* Prints and skips a line. *) @@ -1121,9 +1172,6 @@ begin 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 @@ -1175,10 +1223,8 @@ begin li t1, '@' beq t0, t1, .compile_global_initializer_pointer - la a0, source_code_position - lw a0, (a0) - lb a0, (a0) - _is_digit(); + v0 := _load_byte(source_code_position); + _is_digit(v0); bnez a0, .compile_global_initializer_number unimp @@ -1373,7 +1419,13 @@ begin _skip_empty_lines(); _compile_var_part(); - _write_z(".section .text\n\0"); + _write_z(".section .text\n\n\0"); + _write_z(".type _syscall, @function\n_syscall:\n\tmv a7, a6\n\tecall\n\tret\n\n\0"); + _write_z(".type _load_byte, @function\n_load_byte:\n\tlb a0, (a0)\nret\n\n\0"); + _write_z(".type _load_word, @function\n_load_word:\n\tlw a0, (a0)\nret\n\n\0"); + _write_z(".type _store_byte, @function\n_store_byte:\n\tsb a0, (a1)\nret\n\n\0"); + _write_z(".type _store_word, @function\n_store_word:\n\tsw a0, (a1)\nret\n\n\0"); + .compile_module_loop: _skip_empty_lines(); @@ -1413,10 +1465,9 @@ begin lw t1, 4(sp) bge t0, t1, .compile_end - lb a0, (t0) - addi t0, t0, 1 - sw t0, 0(sp) - _write_c(); + v8 := _load_byte(v0); + v0 := v0 + 1; + _write_c(v8); j .compile_loop @@ -1431,8 +1482,7 @@ end; (* a0 - Status code. *) proc _exit(); begin - li a7, 93 # SYS_EXIT - ecall + _syscall(0, 0, 0, 0, 0, 0, 93); end; (* Inserts a symbol into the table. *) @@ -1554,7 +1604,7 @@ begin sw t1, (t0) end; -proc _initialize_classification(); +proc _create_classification(); begin _assign_at(@classification, 1, 15); _assign_at(@classification, 2, 1); @@ -1688,13 +1738,13 @@ begin v0 := 129; (* Set the remaining 129 - 256 bytes to transitionClassOther. *) -.initialize_classification_loop: +.create_classification_loop: _assign_at(@classification, v0, 22); v0 := v0 + 1; lw t0, 0(sp) li t1, 257 - blt t0, t1, .initialize_classification_loop + blt t0, t1, .create_classification_loop end; (* Parameters: *) @@ -1772,7 +1822,7 @@ end; (* - 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(); +proc _create_transitions(); begin (* Start state. *) _set_transition(1, 1, 1, 16); @@ -1896,8 +1946,7 @@ end; (* Gets pointer to the current source text. *) proc _lexer_get_current(); begin - _lexer_get_state(); - sw a0, 0(sp) + v0 := _lexer_get_state(); return v0 + 4 end; @@ -1925,8 +1974,8 @@ end; (* One time lexer initialization. *) proc _lexer_initialize(); begin - _initialize_classification(); - _initialize_transitions(); + _create_classification(); + _create_transitions(); end; (* Entry point. *)