diff options
Diffstat (limited to '04b/in03')
| -rw-r--r-- | 04b/in03 | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/04b/in03 b/04b/in03 new file mode 100644 index 0000000..dbc78e4 --- /dev/null +++ b/04b/in03 @@ -0,0 +1,487 @@ +; initialize global_variables_end +C=:global_variables_end +D=:global_variables +8C=D +; initialize static_memory_end +C=:static_memory_end +D=x500000 + +I=8S +A=d3 +?I!A:usage_error +; open input file + J=S + ; argv[1] is at *(rsp+16) + J+=d16 + J=8J + I=d0 + syscall x2 + J=A + ?J<0:input_file_error +; open output file + J=S + ; argv[2] is at *(rsp+24) + J+=d24 + J=8J + I=x241 + D=x1ed + syscall x2 + J=A + ?J<0:output_file_error + +:read_line +; increment line number +D=:line_number +C=8D +C+=d1 +8D=C + +; use rbp to store line pointer +R=:line +:read_line_loop + ; read 1 byte into rbp + J=d3 + I=R + D=d1 + syscall x0 + D=A + ?D=0:eof + + ; check if the character was a newline: + C=1R + D=xa + ?C=D:read_line_loop_end + ; check if the character was a tab: + D=x9 + ; if so, don't increment rbp + ?C=D:read_line + ; check if the character was a semicolon: + D='; + ; if so, it's a comment + ?C=D:handle_comment + + R+=d1 + !:read_line_loop + + :handle_comment + ; read out rest of line from file + J=d3 + I=R + D=d1 + syscall x0 + D=A + ?D=0:eof + C=1R + D=xa + ; if we didn't reach the end of the line, keep going + ?C!D:handle_comment + + !:read_line_loop_end +:read_line_loop_end + +; remove whitespace (specifically, ' ' characters) at end of line +I=R +:remove_terminal_whitespace_loop + I-=d1 + C=1I + D=x20 + ?C!D:remove_terminal_whitespace_loop_end + ; replace ' ' with a newline + D=xa + 1I=D + !:remove_terminal_whitespace_loop +:remove_terminal_whitespace_loop_end + +; check if this is a blank line +C=:line +D=1C +C=xa +?C=D:read_line + +I=:line +J=:"global" +C=x20 +call :string= +D=A +?D!0:handle_global + + +!:read_line + +:eof + J=d0 + syscall x3c + +:handle_global + I=:line + ; skip "global " + I+=d7 + call :read_type + ; put type in R + R=A + ; skip ' ' after type + I+=d1 + J=:global_variables_end + J=8J + call :ident_copy + ; store type + 1J=R + J+=d1 + ; store address + D=:static_memory_end + D=8D + 8J=D + ; update :static_memory_end + D=:static_memory_end + C=8D + C+=d8 + 8D=C + ; update :global_variables_end + I=:global_variables_end + 8I=J + ; go read the next line + !:read_line + +:"global" + str global + x20 + +; copy the newline-terminated identifier from rsi to rdi +:ident_copy + C=1I + B=C + call :isident + D=A + ?D=0:bad_identifier + + :ident_loop + C=1I + D=xa + ?C=D:ident_loop_end + B=C + call :isident + D=A + ?D=0:bad_identifier + C=1I + 1J=C + I+=d1 + J+=d1 + !:ident_loop + :ident_loop_end + return + + +; can the character in rbx appear in an identifier? +:isident + A='0 + ?B<A:return_0 + ; note: 58 = '9' + 1 + A=d58 + ?B<A:return_1 + A='A + ?B<A:return_0 + ; note: 91 = 'z' + 1 + A=d91 + ?B<A:return_1 + A='z + ?B>A:return_0 + ; 96 = 'a' - 1 + A=d96 + ?B>A:return_1 + A='_ + ?B=A:return_1 + !:return_0 + +; read the space-terminated type from rsi, advance rsi, and set rax to the corresponding type number: +; 0 for non-pointer types +; 1 for pointer to char +; 2 for pointer to short +; 4 for pointer to int +; 8 for pointer to long +:read_type + C=1I + D='* + ?C=D:read_pointer_type + ; it's not a pointer + call :read_simple_type + A=d0 + return + :read_pointer_type + ; it's a pointer! + I+=d1 + !:read_simple_type + +; returns 1 for char, 2 for short, 4 for int, 8 for long +:read_simple_type + R=I + C=x20 + I=R + J=:"char" + call :string= + D=A + ?D!0:return_1 + I=R + J=:"short" + call :string= + D=A + ?D!0:return_2 + I=R + J=:"int" + call :string= + D=A + ?D!0:return_4 + I=R + J=:"long" + call :string= + D=A + ?D!0:return_8 + !:bad_type + +:"char" + str char + x20 +:"short" + str short + x20 +:"int" + str int + x20 +:"long" + str long + x20 + + +:usage_error + B=:usage_error_message + call :general_error + +:usage_error_message + str Please provide an input and an output file. + xa + x0 + +:input_file_error + B=:input_file_error_message + !:general_error + +:input_file_error_message + str Couldn't open input file. + xa + x0 + +:output_file_error + B=:output_file_error_message + !:general_error + +:output_file_error_message + str Couldn't open output file. + xa + x0 + +:bad_identifier + B=:bad_identifier_error_message + !:program_error + +:bad_identifier_error_message + str Bad identifier. + xa + x0 + +:bad_type + B=:bad_type_error_message + !:program_error + +:bad_type_error_message + str Bad type. + xa + x0 + +:general_error + call :eputs + J=d1 + syscall x3c + +:program_error + R=B + + B=:"Line" + call :eputs + + D=:line_number + D=8D + B=D + call :eputn + + B=:line_number_separator + call :eputs + + B=R + call :eputs + J=d1 + syscall x3c + +:"Line" + str Line + x20 + x0 + +:line_number_separator + str : + x20 + x0 + +:strlen + I=B + D=B + :strlen_loop + C=1I + ?C=0:strlen_ret + I+=d1 + !:strlen_loop + :strlen_ret + I-=D + A=I + return + +; check if strings in rdi and rsi are equal, up to terminator in rcx +:string= + D=1I + A=1J + ?D!A:return_0 + ?D=C:return_1 + I+=d1 + J+=d1 + !:string= + +; check if strings in rdi and rsi are equal, up to the first non-identifier character +:ident= + D=1I + B=D + call :isident + ; I ended + ?A=0:ident=_I_end + + D=1J + B=D + call :isident + ; J ended, but I didn't + ?A=0:return_0 + + ; we haven't reached the end of either + D=1I + A=1J + ?D!A:return_0 + I+=d1 + J+=d1 + !:ident= +:ident=_I_end + D=1J + B=D + call :isident + ; check if J also ended + ?A=0:return_1 + ; J didn't end + !:return_0 + +:return_0 + A=d0 + return +:return_1 + A=d1 + return +:return_2 + A=d2 + return +:return_3 + A=d3 + return +:return_4 + A=d4 + return +:return_5 + A=d5 + return +:return_6 + A=d6 + return +:return_7 + A=d7 + return +:return_8 + A=d8 + return + +; write the character in rbx to the file in rdi. +:fputc + C=B + I=S + I-=d1 + 1I=C + D=d1 + syscall x1 + return + +; write the string in rbx to stderr +:eputs + J=B + call :strlen + D=A + I=J + J=d2 + syscall x1 + return + +; write rbx in decimal to stderr +:eputn + I=B + J=S + J-=d1 + :eputn_loop + D=d0 + ; divide by 10 + B=d10 + A=I + div + ; quotient is new number + I=A + ; add remainder to string + D+='0 + 1J=D + J-=d1 + ?I!0:eputn_loop + D=S + D-=J + I=J + J=d2 + syscall x1 + return + +; copy rdx bytes from rsi to rdi. +; this copies from the left: if you're doing an overlapped copy, rsi should be greater than rdi +:memcpy + ?D=0:return_0 + A=1I + 1J=A + I+=d1 + J+=d1 + D-=d1 + !:memcpy + +; put a 0 byte before the line (this is important for removing whitespace at the end of the line, +; specifically, we don't want this to be a space character) +x0 +:line + reserve d1000 + +align +:global_variables_end + reserve d8 +:static_memory_end + reserve d8 +:line_number + reserve d8 +:global_variables + reserve d50000 + +; we shouldn't end the file with a reserve; we don't handle that properly +x00 |