diff options
Diffstat (limited to 'subx/062write-stream.subx')
| -rw-r--r-- | subx/062write-stream.subx | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/subx/062write-stream.subx b/subx/062write-stream.subx new file mode 100644 index 00000000..f112dee9 --- /dev/null +++ b/subx/062write-stream.subx @@ -0,0 +1,243 @@ +# write-stream: like write, but write streams rather than strings + +== code +# instruction effective address register displacement immediate +# . op subop mod rm32 base index scale r32 +# . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes + +# main: + # manual test +#? # write-stream(stdout, _test-stream2) +#? 68/push _test-stream2/imm32 +#? 68/push 1/imm32/stdout +#? e8/call write-stream/disp32 + # automatic test +#? e8/call test-write-stream-appends/disp32 + e8/call run-tests/disp32 # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'. + # syscall(exit, Num-test-failures) + 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 3/r32/EBX Num-test-failures/disp32 # copy *Num-test-failures to EBX + b8/copy-to-EAX 1/imm32/exit + cd/syscall 0x80/imm8 + +write-stream: # f : fd or (address stream), s : (address stream) -> <void> + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # if (f < 0x08000000) _write-stream(f, s), return # f can't be a user-mode address, so treat it as a kernel file descriptor + 81 7/subop/compare 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 0x08000000/imm32 # compare *(EBP+8) + 7d/jump-if-greater-or-equal $write-stream:fake/disp8 + # . . push args + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) + # . . call + e8/call _write-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + eb/jump $write-stream:end/disp8 +$write-stream:fake: + # otherwise, treat 'f' as a stream to append to + # . save registers + 50/push-EAX + 56/push-ESI + 57/push-EDI + # EDI = f + 8b/copy 1/mod/*+disp8 5/rm32/EBP . . 7/r32/EDI 8/disp8 . # copy *(EBP+8) to EDI + # ESI = s + 8b/copy 1/mod/*+disp8 5/rm32/EBP . . 6/r32/ESI 0xc/disp8 . # copy *(EBP+12) to ESI + # EAX = _append-4(&f->data[f->write], &f->data[f->length], &s->data[s->read], &s->data[s->write]) + # . . push &s->data[s->write] + 8b/copy 0/mod/indirect 6/rm32/ESI . . . 0/r32/EAX . . # copy *ESI to EAX + 8d/copy-address 1/mod/*+disp8 4/rm32/sib 6/base/ESI 0/index/EAX . 0/r32/EAX 0xc/disp8 . # copy ESI+EAX+12 to EAX + 50/push-EAX + # . . push &s->data[s->read] + 8b/copy 1/mod/*+disp8 6/rm32/ESI . . . 0/r32/EAX 4/disp8 . # copy *(ESI+4) to EAX + 8d/copy-address 1/mod/*+disp8 4/rm32/sib 6/base/ESI 0/index/EAX . 0/r32/EAX 0xc/disp8 . # copy ESI+EAX+12 to EAX + 50/push-EAX + # . . push &f->data[f->length] + 8b/copy 1/mod/*+disp8 7/rm32/EDI . . . 0/r32/EAX 8/disp8 . # copy *(EDI+8) to EAX + 8d/copy-address 1/mod/*+disp8 4/rm32/sib 7/base/EDI 0/index/EAX . 0/r32/EAX 0xc/disp8 . # copy EDI+EAX+12 to EAX + 50/push-EAX + # . . push &f->data[f->write] + 8b/copy 0/mod/indirect 7/rm32/EDI . . . 0/r32/EAX . . # copy *EDI to EAX + 8d/copy-address 1/mod/*+disp8 4/rm32/sib 7/base/EDI 0/index/EAX . 0/r32/EAX 0xc/disp8 . # copy EDI+EAX+12 to EAX + 50/push-EAX + # . . call + e8/call _append-4/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0x10/imm32 # add to ESP + # f->write += EAX + 01/add 0/mod/indirect 7/rm32/EDI . . . 0/r32/EAX . . # add EAX to *EDI + # s->read += EAX + 01/add 1/mod/*+disp8 6/rm32/ESI . . . 0/r32/EAX 4/disp8 . # add EAX to *(ESI+4) + # . restore registers + 5f/pop-to-EDI + 5e/pop-to-ESI + 58/pop-to-EAX +$write-stream:end: + # . epilog + 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP + 5d/pop-to-EBP + c3/return + +_write-stream: # fd : int, s : (address stream) -> <void> + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # . save registers + 50/push-EAX + 51/push-ECX + 52/push-EDX + 53/push-EBX + 56/push-ESI + 57/push-EDI + # ESI = s + 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 6/r32/ESI 0xc/disp8 . # copy *(EBP+12) to ESI + # EDI = s->read + 8b/copy 1/mod/*+disp8 6/rm32/ESI . . . 7/r32/EDI 4/disp8 . # copy *(ESI+4) to EDI + # EDX = s->write + 8b/copy 0/mod/indirect 6/rm32/ESI . . . 2/r32/EDX . . # copy *ESI to EDX + # syscall(write, fd, &s->data[s->read], s->write - s->read) + # . . fd : EBX + 8b/copy 1/mod/*+disp8 5/rm32/EBP . . . 3/r32/EBX 8/disp8 . # copy *(EBP+8) to EBX + # . . data : ECX = &s->data[s->read] + 8d/copy-address 1/mod/*+disp8 4/rm32/sib 6/base/ESI 7/index/EDI . 1/r32/ECX 0xc/disp8 . # copy ESI+EDI+12 to ECX + # . . size : EDX = s->write - s->read + 29/subtract 3/mod/direct 2/rm32/EDX . . . 7/r32/EDI . . # subtract EDI from EDX + # . . syscall + b8/copy-to-EAX 4/imm32/write + cd/syscall 0x80/imm8 + # . restore registers + 5f/pop-to-EDI + 5e/pop-to-ESI + 5b/pop-to-EBX + 5a/pop-to-EDX + 59/pop-to-ECX + 58/pop-to-EAX + # . epilog + 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP + 5d/pop-to-EBP + c3/return + +test-write-stream-single: + # setup + # . clear-stream(_test-stream) + # . . push args + 68/push _test-stream/imm32 + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # . clear-stream(_test-stream2) + # . . push args + 68/push _test-stream2/imm32 + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # . write(_test-stream2, "Ab") + # . . push args + 68/push "Ab"/imm32 + 68/push _test-stream2/imm32 + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # write-stream(_test-stream, _test-stream2) + # . . push args + 68/push _test-stream2/imm32 + 68/push _test-stream/imm32 + # . . call + e8/call write-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # check-ints-equal(*_test-stream->data, 41/A 62/b 00 00, msg) + # . . push args + 68/push "F - test-write-stream-single"/imm32 + 68/push 0x006241/imm32/Ab + # . . push *_test-stream->data + b8/copy-to-EAX _test-stream/imm32 + ff 6/subop/push 1/mod/*+disp8 0/rm32/EAX . . . . 0xc/disp8 . # push *(EAX+12) + # . . call + e8/call check-ints-equal/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP + # . end + c3/return + +test-write-stream-appends: + # setup + # . clear-stream(_test-stream) + # . . push args + 68/push _test-stream/imm32 + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # . clear-stream(_test-stream2) + # . . push args + 68/push _test-stream2/imm32 + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # . write(_test-stream2, "C") + # . . push args + 68/push "C"/imm32 + 68/push _test-stream2/imm32 + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # first write + # . write-stream(_test-stream, _test-stream2) + # . . push args + 68/push _test-stream2/imm32 + 68/push _test-stream/imm32 + # . . call + e8/call write-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # second write + # . write(_test-stream2, "D") + # . . push args + 68/push "D"/imm32 + 68/push _test-stream2/imm32 + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # . write-stream(_test-stream, _test-stream2) + # . . push args + 68/push _test-stream2/imm32 + 68/push _test-stream/imm32 + # . . call + e8/call write-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # check-ints-equal(*_test-stream->data, 43/C 44/D 00 00, msg) + # . . push args + 68/push "F - test-write-stream-appends"/imm32 + 68/push 0x00004443/imm32/C-D + # . . push *_test-stream->data + b8/copy-to-EAX _test-stream/imm32 + ff 6/subop/push 1/mod/*+disp8 0/rm32/EAX . . . . 0xc/disp8 . # push *(EAX+12) + # . . call + e8/call check-ints-equal/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP + # . end + c3/return + +== data + +_test-stream2: + # current write index + 04 00 00 00 + # current read index + 01 00 00 00 + # length (= 8) + 08 00 00 00 + # data + 41 42 43 44 00 00 00 00 # 8 bytes + +# . . vim:nowrap:textwidth=0 |