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| author | Kartik Agaram <vc@akkartik.com> | 2019-02-03 23:29:46 -0800 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2019-02-03 23:29:46 -0800 |
| commit | 51b4f888dd20653bb218f06e1221a7007446fcd5 (patch) | |
| tree | 7458e3eebfc7e5df9903219603d5f8cda87f74af /subx/068error-byte.subx | |
| parent | 03c6f1d3858ff0fdb6af6ce4b61bea51f16b33be (diff) | |
| download | mu-51b4f888dd20653bb218f06e1221a7007446fcd5.tar.gz | |
4950
Diffstat (limited to 'subx/068error-byte.subx')
| -rw-r--r-- | subx/068error-byte.subx | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/subx/068error-byte.subx b/subx/068error-byte.subx new file mode 100644 index 00000000..5f9a4ada --- /dev/null +++ b/subx/068error-byte.subx @@ -0,0 +1,112 @@ +# Print an error message followed by the text representation of a byte. Then exit. + +== 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 +#? # . var ed/EAX : exit-descriptor +#? 81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # subtract from ESP +#? 89/copy 3/mod/direct 0/rm32/EAX . . . 4/r32/ESP . . # copy ESP to EAX +#? # . configure ed to really exit() +#? # . . ed->target = 0 +#? c7 0/subop/copy 0/mod/direct 0/rm32/EAX . . . . . 0/imm32 # copy to *EAX +#? # . error-byte(ed, Stdout, msg, 34) +#? 68/push 0x34/imm32 +#? 68/push "abc"/imm32 +#? 68/push Stderr/imm32 +#? 50/push-EAX +#? e8/call error-byte/disp32 + # automatic test + 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(out, "Error: "+msg+": "+byte) then stop(ed, 1) +error-byte: # ed : (address exit-descriptor), out : (address buffered-file), msg : (address array byte), n : byte -> <void> + # . prolog + 55/push-EBP + 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP + # write-buffered(out, "Error: ") + # . . push args + 68/push "Error: "/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write-buffered/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # write-buffered(out, msg) + # . . push args + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x10/disp8 . # push *(EBP+16) + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write-buffered/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # write-buffered(out, ": ") + # . . push args + 68/push ": "/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write-buffered/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # print-byte(out, byte) + # . . push args + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x14/disp8 . # push *(EBP+20) + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call print-byte/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # write-buffered(out, Newline) + # . . push args + 68/push Newline/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write-buffered/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # . flush(out) + # . . push args + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call flush/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # stop(ed, 1) + # . . push args + 68/push 1/imm32 + ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) + # . . call + e8/call stop/disp32 + # should never get past this point +$error-byte:dead-end: + # . epilog + 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP + 5d/pop-to-EBP + c3/return + +== data + +# The buffered file for standard error. +Stderr: + # file descriptor or (address stream) + 02 00 00 00 # 1 = standard error + # current write index + 00 00 00 00 + # current read index + 00 00 00 00 + # length (8) + 08 00 00 00 + # data + 00 00 00 00 00 00 00 00 # 8 bytes + +# TODO: 8 bytes is too small. We'll need to grow the buffer for efficiency. But +# I don't want to type in 1024 bytes here. + +# . . vim:nowrap:textwidth=0 |