# write: like _write, but also support in-memory streams in addition to file
# descriptors.
#
# Our first dependency-injected and testable primitive. We can pass it either
# a file descriptor or an address to a stream. If a file descriptor is passed
# in, we _write to it using the right syscall. If a 'fake file descriptor' or
# stream is passed in, we append to the stream. This lets us redirect output
# in tests and check it later.
#
# We assume our data segment will never begin at an address shorter than
# 0x08000000, so any smaller arguments are assumed to be real file descriptors.
#
# A stream looks like this:
# read: int # index at which to read next
# write: int # index at which writes go
# data: (array byte) # prefixed by size as usual
== 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
# TODO: come up with a way to signal when a write to disk fails
write: # f: fd or (addr stream byte), s: (addr array byte)
# . prologue
55/push-ebp
89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
# if (s == 0) return
81 7/subop/compare 1/mod/*+disp8 5/rm32/ebp . . . . 0xc/disp8 0/imm32 # compare *(ebp+12)
74/jump-if-= $write:end/disp8
# if (f < 0x08000000) _write(f, s) and 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)
73/jump-if-addr>= $write: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/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
eb/jump $write:end/disp8
$write:fake:
# otherwise, treat 'f' as a stream to append to
# . save registers
50/push-eax
51/push-ecx
52/push-edx
53/push-ebx
# ecx = f
8b/copy 1/mod/*+disp8 5/rm32/ebp . . 1/r32/ecx 8/disp8 . # copy *(ebp+8) to ecx
# edx = f->write
8b/copy 0/mod/indirect 1/rm32/ecx . . . 2/r32/edx . . # copy *ecx to edx
# ebx = f->size
8b/copy 1/mod/*+disp8 1/rm32/ecx . . . 3/r32/ebx 8/disp8 . # copy *(ecx+8) to ebx
# eax = _append-3(&f->data[f->write], &f->data[f->size], s)
# . . push s
ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0xc/disp8 . # push *(ebp+12)
# . . push &f->data[f->size]
8d/copy-address 1/mod/*+disp8 4/rm32/sib 1/base/ecx 3/index/ebx . 3/r32/ebx 0xc/disp8 . # copy ecx+ebx+12 to ebx
53/push-ebx
# . . push &f->data[f->write]
8d/copy-address 1/mod/*+disp8 4/rm32/sib 1/base/ecx 2/index/edx . 3/r32/ebx 0xc/disp8 . # copy ecx+edx+12 to ebx
53/push-ebx
# . . call
e8/call _append-3/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# f->write += eax
01/add 0/mod/indirect 1/rm32/ecx . . . 0/r32/eax . . # add eax to *ecx
# . restore registers
5b/pop-to-ebx
5a/pop-to-edx
59/pop-to-ecx
58/pop-to-eax
$write:end:
# . epilogue
89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
5d/pop-to-ebp
c3/return
test-write-single:
# clear-stream(_test-stream)
# . . push args
68/push _test-stream/imm32
# . . call
== 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
# If datum of 'word' is not a valid name, it must be a hex int. Parse and print
# it in 'width' bytes of hex, least significant first.
# Otherwise just print the entire word including metadata.
# Always print a trailing space.
emit: # out: (addr buffered-file), word: (addr slice), width: int
# . prologue
55/push-ebp
89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
# . save registers
50/push-eax
56/push-esi
57/push-edi
# esi = word
8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 6/r32/esi 0xc/disp8 . # copy *(ebp+12) to esi
# var datum/edi: slice
68/push 0/imm32/end
68/push 0/imm32/start
89/copy 3/mod/direct 7/rm32/edi . . . 4/r32/esp . . # copy esp to edi
# datum = next-token-from-slice(word->start, word->end, '/')
# . . push args
57/push-edi
68/push 0x2f/imm32/slash
ff 6/subop/push 1/mod/*+disp8 6/rm32/esi . . . . 4/disp8 . # push *(esi+4)
ff 6/subop/push 0/mod/indirect 6/rm32/esi . . . . . . # push *esi
# . . call
e8/call next-token-from-slice/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0x10/imm32 # add to esp
# if (is-valid-name?(datum)) write-slice-buffered(out, word) and return
# . eax = is-valid-name?(name)
# . . push args
57/push-edi
# . . call
e8/call is-valid-name?/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# . if (eax != false)
3d/compare-eax-and 0/imm32/false
74/jump-if-= $emit:hex-int/disp8
$emit:name:
# . write-slice-buffered(out, word)
# . . push args
56/push-esi
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-buffered(out, " ")
# . . push args
68/push Space/imm32
ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8)
# . . call
e8/call write-buffered/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
# . return
eb/jump $emit:end/disp8
# otherwise emit-hex(out, parse-hex-int(datum), width)
# (Weird shit can happen here if the datum of 'word' isn't either a valid
# name or a hex number. `emit` is mostly used by translate_subx, which
# is currently designed to only receive legal SubX programs. We just
# want to make sure that valid names aren't treated as (valid) hex
# numbers.)
$emit:hex-int:
# . var value/eax: int = parse-hex-int(datum)
# . . push args
57/push-edi
# . . call
e8/call parse-hex-int/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# . emit-hex(out, value, width)
# . . push args
ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0x10/disp8 . # push *(ebp+16)
50/push-eax
ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8)
# . . call
e8/call emit-hex/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
$emit:end:
# . reclaim locals
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
# . restore registers
5f/pop-to-edi
5e/pop-to-esi
58/pop-to-eax
# . epilogue
89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
5d/pop-to-ebp
c3/return
test-emit-number:
# . prologue
55/push-ebp
89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
# setup
# . clear-stream(_test-output-stream)
# . . push args
68/push _test-output-stream/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# . clear-stream($_test-output-buffered-file->buffer)
# . . push args
68/push $_test-output-buffered-file->buffer/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# (eax..ecx) = "30"
b8/copy-to-eax "30"/imm32
8b/copy 0/mod/indirect 0/rm32/eax . . . 1/r32/ecx . . # copy *eax to ecx
8d/copy-address 1/mod/*+disp8 4/rm32/sib 0/base/eax 1/index/ecx . 1/r32/ecx 4/disp8 . # copy eax+ecx+4 to ecx
05/add-to-eax 4/imm32
# var slice/ecx: slice = {eax, ecx}
51/push-ecx
50/push-eax
89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
# emit(_test-output-buffered-file, slice, 1)
# . . push args
68/push 1/imm32
51/push-ecx
68/push _test-output-buffered-file/imm32
# . . call
e8/call emit/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# flush(_test-output-buffered-file)
# . . push args
68/push _test-output-buffered-file/imm32
# . . call
e8/call flush/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# check-stream-equal(_test-output-stream, "30 ", msg)
# . . push args
68/push "F - test-emit-number/1"/imm32
68/push "30 "/imm32
68/push _test-output-stream/imm32
# . . call
e8/call check-stream-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# . epilogue
89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
5d/pop-to-ebp
c3/return
test-emit-negative-number:
# test support for sign-extending negative numbers
# . prologue
55/push-ebp
89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
# setup
# . clear-stream(_test-output-stream)
# . . push args
68/push _test-output-stream/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# . clear-stream($_test-output-buffered-file->buffer)
# . . push args
68/push $_test-output-buffered-file->buffer/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# (eax..ecx) = "-2"
b8/copy-to-eax "-2"/imm32
8b/copy 0/mod/indirect 0/rm32/eax . . . 1/r32/ecx . . # copy *eax to ecx
8d/copy-address 1/mod/*+disp8 4/rm32/sib 0/base/eax 1/index/ecx . 1/r32/ecx 4/disp8 . # copy eax+ecx+4 to ecx
05/add-to-eax 4/imm32
# var slice/ecx: slice = {eax, ecx}
51/push-ecx
50/push-eax
89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
# emit(_test-output-buffered-file, slice, 2)
# . . push args
68/push 2/imm32
51/push-ecx
68/push _test-output-buffered-file/imm32
# . . call
e8/call emit/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# flush(_test-output-buffered-file)
# . . push args
68/push _test-output-buffered-file/imm32
# . . call
e8/call flush/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# check-stream-equal(_test-output-stream, "fe ff ", msg)
# . . push args
68/push "F - test-emit-number/1"/imm32
68/push "fe ff "/imm32
68/push _test-output-stream/imm32
# . . call
e8/call check-stream-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# . epilogue
89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
5d/pop-to-ebp
c3/return
test-emit-number-with-metadata:
# . prologue
55/push-ebp
89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
# setup
# . clear-stream(_test-output-stream)
# . . push args
68/push _test-output-stream/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# . clear-stream($_test-output-buffered-file->buffer)
# . . push args
68/push $_test-output-buffered-file->buffer/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# (eax..ecx) = "-2/foo"
b8/copy-to-eax "-2/foo"/imm32
8b/copy 0/mod/indirect 0/rm32/eax . . . 1/r32/ecx . . # copy *eax to ecx
8d/copy-address 1/mod/*+disp8 4/rm32/sib 0/base/eax 1/index/ecx . 1/r32/ecx 4/disp8 . # copy eax+ecx+4 to ecx
05/add-to-eax 4/imm32
# var slice/ecx: slice = {eax, ecx}
51/push-ecx
50/push-eax
89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
# emit(_test-output-buffered-file, slice, 2)
# . . push args
68/push 2/imm32
51/push-ecx
68/push _test-output-buffered-file/imm32
# . . call
e8/call emit/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# flush(_test-output-buffered-file)
# . . push args
68/push _test-output-buffered-file/imm32
# . . call
e8/call flush/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# the '/foo' will have no impact on the output
# check-stream-equal(_test-output-stream, "fe ff ", msg)
# . . push args
68/push "F - test-emit-number-with-metadata"/imm32
68/push "fe ff "/imm32
68/push _test-output-stream/imm32
# . . call
e8/call check-stream-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# . epilogue
89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
5d/pop-to-ebp
c3/return
test-emit-non-number:
# . prologue
55/push-ebp
89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
# setup
# . clear-stream(_test-output-stream)
# . . push args
68/push _test-output-stream/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# . clear-stream($_test-output-buffered-file->buffer)
# . . push args
68/push $_test-output-buffered-file->buffer/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# (eax..ecx) = "xyz"
b8/copy-to-eax "xyz"/imm32
8b/copy 0/mod/indirect 0/rm32/eax . . . 1/r32/ecx . . # copy *eax to ecx
8d/copy-address 1/mod/*+disp8 4/rm32/sib 0/base/eax 1/index/ecx . 1/r32/ecx 4/disp8 . # copy eax+ecx+4 to ecx
05/add-to-eax 4/imm32
# var slice/ecx: slice = {eax, ecx}
51/push-ecx
50/push-eax
89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
# emit(_test-output-buffered-file, slice, 2)
# . . push args
68/push 2/imm32
51/push-ecx
68/push _test-output-buffered-file/imm32
# . . call
e8/call emit/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# flush(_test-output-buffered-file)
# . . push args
68/push _test-output-buffered-file/imm32
# . . call
e8/call flush/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# check-stream-equal(_test-output-stream, "xyz", msg)
# . . push args
68/push "F - test-emit-non-number"/imm32
68/push "xyz "/imm32
68/push _test-output-stream/imm32
# . . call
e8/call check-stream-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# . epilogue
89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
5d/pop-to-ebp
c3/return
test-emit-non-number-with-metadata:
# . prologue
55/push-ebp
89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
# setup
# . clear-stream(_test-output-stream)
# . . push args
68/push _test-output-stream/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# . clear-stream($_test-output-buffered-file->buffer)
# . . push args
68/push $_test-output-buffered-file->buffer/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# (eax..ecx) = "xyz/"
b8/copy-to-eax "xyz/"/imm32
8b/copy 0/mod/indirect 0/rm32/eax . . . 1/r32/ecx . . # copy *eax to ecx
8d/copy-address 1/mod/*+disp8 4/rm32/sib 0/base/eax 1/index/ecx . 1/r32/ecx 4/disp8 . # copy eax+ecx+4 to ecx
05/add-to-eax 4/imm32
# var slice/ecx: slice = {eax, ecx}
51/push-ecx
50/push-eax
89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
# emit(_test-output-buffered-file, slice, 2)
# . . push args
68/push 2/imm32
51/push-ecx
68/push _test-output-buffered-file/imm32
# . . call
e8/call emit/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# flush(_test-output-buffered-file)
# . . push args
68/push _test-output-buffered-file/imm32
# . . call
e8/call flush/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# check-stream-equal(_test-output-stream, "xyz/", msg)
# . . push args
68/push "F - test-emit-non-number-with-metadata"/imm32
68/push "xyz/ "/imm32
68/push _test-output-stream/imm32
# . . call
e8/call check-stream-equal/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# . epilogue
89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp
5d/pop-to-ebp
c3/return
test-emit-non-number-with-all-hex-digits-and-metadata:
# . prologue
55/push-ebp
89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp
# setup
# . clear-stream(_test-output-stream)
# . . push args
68/push _test-output-stream/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# . clear-stream($_test-output-buffered-file->buffer)
# . . push args
68/push $_test-output-buffered-file->buffer/imm32
# . . call
e8/call clear-stream/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
# (eax..ecx) = "abcd/xyz"
b8/copy-to-eax "abcd/xyz"/imm32
8b/copy 0/mod/indirect 0/rm32/eax . . . 1/r32/ecx . . # copy *eax to ecx
8d/copy-address 1/mod/*+disp8 4/rm32/sib 0/base/eax 1/index/ecx . 1/r32/ecx 4/disp8 . # copy eax+ecx+4 to ecx
05/add-to-eax 4/imm32
# var slice/ecx: slice = {eax, ecx}
51/push-ecx
50/push-eax
89/copy 3/mod/direct 1/rm32/ecx . . . 4/r32/esp . . # copy esp to ecx
# emit(_test-output-buffered-file, slice, 2)
# . . push args
68/push 2/imm32
51/push-ecx
68/push _test-output-buffered-file/imm32
# . . call
e8/call emit/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp
# flush(_test-output-buffered-file)
# . . push args
68/push _test-output-buffered-file/imm32
# . . call
e8/call flush/disp32
# . . discard args
81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp
#? # dump output {{{
#? # . write(2/stderr, "^")
#? # . . push args
#? 68/push "^"/imm32
#? 68/push 2/imm32/stderr
#? # . . call
#? e8/call write/disp32
#? # . . discard args
#? 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
#? # . write-stream(2/stderr, _test-output-stream)
#? # . . push args
#? 68/push _test-output-stream/imm32
#? 68/push 2/imm32/stderr
#? # . . call
#? e8/call write-stream/disp32
#? # . . discard args
#? 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp
#? # . write(2/stderr, "$\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
#? # }}}
# check-stream-equal(_test-output-stream, "abcd/xyz")
# . . push args
68/push "F - test-emit-non-number-with-all-hex-digits"/imm32
68/push "abcd/xyz "/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