diff options
Diffstat (limited to 'linux/125write-stream-data.subx')
| -rw-r--r-- | linux/125write-stream-data.subx | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/linux/125write-stream-data.subx b/linux/125write-stream-data.subx new file mode 100644 index 00000000..0cc8ba65 --- /dev/null +++ b/linux/125write-stream-data.subx @@ -0,0 +1,114 @@ +== 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 + +# write an entire stream's contents to a buffered-file +# ways to do this: +# - construct a 'maximal slice' and pass it to write-slice-buffered +# - flush the buffered-file and pass the stream directly to its fd (disabling buffering) +# we'll go with the first way for now +write-stream-data: # f: (addr buffered-file), s: (addr stream byte) + # . prologue + 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 + 56/push-esi + # esi = s + 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 6/r32/esi 0xc/disp8 . # copy *(ebp+12) to esi + # var slice/ecx: slice = {s->data, &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 + 8d/copy-address 1/mod/*+disp8 6/rm32/esi . . . 0/r32/eax 0xc/disp8 . # copy esi+12 to eax + 50/push-eax + # . ecx = esp + 89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx + # write-slice-buffered(f, slice) + # . . push args + 51/push-ecx + ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8) + # . . call + e8/call write-slice-buffered/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp +$write-stream-data:end: + # . restore locals + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp + # . restore registers + 5e/pop-to-esi + 59/pop-to-ecx + 58/pop-to-eax + # . epilogue + 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp + 5d/pop-to-ebp + c3/return + +test-write-stream-data: + # . prologue + 55/push-ebp + 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp + # setup + # . clear-stream(_test-output-stream) + # . . push args + 68/push _test-output-stream/imm32 + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # . clear-stream($_test-output-buffered-file->buffer) + # . . push args + 68/push $_test-output-buffered-file->buffer/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-input-stream) + # . . push args + 68/push _test-input-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 + # initialize input + # . write(_test-input-stream, "abcd") + # . . push args + 68/push "abcd"/imm32 + 68/push _test-input-stream/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-data(_test-output-buffered-file, _test-input-stream) + # . . push args + 68/push _test-input-stream/imm32 + 68/push _test-output-buffered-file/imm32 + # . . call + e8/call write-stream-data/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp + # check that the write happened as expected + # . flush(_test-output-buffered-file) + # . . push args + 68/push _test-output-buffered-file/imm32 + # . . call + e8/call flush/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # . check-stream-equal(_test-output-stream, "abcd", msg) + # . . push args + 68/push "F - test-write-stream-data"/imm32 + 68/push "abcd"/imm32 + 68/push _test-output-stream/imm32 + # . . call + e8/call check-stream-equal/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp + # . epilogue + 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp + 5d/pop-to-ebp + c3/return |