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| author | Kartik Agaram <vc@akkartik.com> | 2019-07-21 22:34:15 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2019-07-21 23:29:38 -0700 |
| commit | 0d219f0a732d81dad124906f5594a06b023fa3a0 (patch) | |
| tree | 1e450a89e25e609c900c57edfb88ded4e96cf8da /subx/067parse-hex.subx | |
| parent | ac8a9396b96259ed2d068abf30863540a21648f3 (diff) | |
| download | mu-0d219f0a732d81dad124906f5594a06b023fa3a0.tar.gz | |
5438 - raise error on uppercase hex
We can now translate layers 49-56 using the self-hosted translator (`translate` and `ntranslate`). As a follow-up to commit 5404, the self-hosted translator is a little more strict than the C++ translator in 3 places: a) All .subx files must define a data segment. b) All .subx files must define an `Entry` label. c) All numbers must be in *lowercase* hex. In all cases, where programs work with the C++ translator but violate the self-hosted translator's assumptions, we must make sure we raise errors rather than silently emit bad code.
Diffstat (limited to 'subx/067parse-hex.subx')
| -rw-r--r-- | subx/067parse-hex.subx | 75 |
1 files changed, 70 insertions, 5 deletions
diff --git a/subx/067parse-hex.subx b/subx/067parse-hex.subx index bbfc4ec9..45d168d9 100644 --- a/subx/067parse-hex.subx +++ b/subx/067parse-hex.subx @@ -795,15 +795,80 @@ test-hex-above-f: c3/return from-hex-char: # in/EAX : byte -> out/EAX : nibble - # no error checking; accepts argument in EAX - # if (EAX <= '9') return EAX - '0' +$from-hex-char:check0: + # if (EAX < '0') goto abort + 3d/compare-EAX-with 0x30/imm32/0 + 7c/jump-if-lesser $from-hex-char:abort/disp8 +$from-hex-char:check1: + # if (EAX > 'f') goto abort + 3d/compare-EAX-with 0x66/imm32/f + 7f/jump-if-greater $from-hex-char:abort/disp8 +$from-hex-char:check2: + # if (EAX > '9') goto next check 3d/compare-EAX-with 0x39/imm32/9 - 7f/jump-if-greater $from-hex-char:else/disp8 + 7f/jump-if-greater $from-hex-char:check3/disp8 +$from-hex-char:digit: + # return EAX - '0' 2d/subtract-from-EAX 0x30/imm32/0 c3/return -$from-hex-char:else: - # otherwise return EAX - 'a' + 10 +$from-hex-char:check3: + # if (EAX < 'a') goto abort + 3d/compare-EAX-with 0x61/imm32/a + 7c/jump-if-lesser $from-hex-char:abort/disp8 +$from-hex-char:letter: + # return EAX - ('a'-10) 2d/subtract-from-EAX 0x57/imm32/a-10 c3/return +$from-hex-char:abort: + # . _write(2/stderr, error) + # . . push args + 68/push "invalid hex char: "/imm32 + 68/push 2/imm32/stderr + # . . call + e8/call _write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # . clear-stream(Stderr+4) + # . . save EAX + 50/push-EAX + # . . push args + b8/copy-to-EAX Stderr/imm32 + 05/add-to-EAX 4/imm32 + 50/push-EAX + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # . . restore EAX + 58/pop-to-EAX + # . print-int32-buffered(Stderr, EAX) + # . . push args + 50/push-EAX + 68/push Stderr/imm32 + # . . call + e8/call print-int32-buffered/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # . flush(Stderr) + # . . push args + 68/push Stderr/imm32 + # . . call + e8/call flush/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP + # . _write(2/stderr, "\n") + # . . push args + 68/push "\n"/imm32 + 68/push 2/imm32/stderr + # . . call + e8/call _write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # . syscall(exit, 1) + bb/copy-to-EBX 1/imm32 + b8/copy-to-EAX 1/imm32/exit + cd/syscall 0x80/imm8 + # never gets here + # . . vim:nowrap:textwidth=0 |