# primitives for emitting traces to a 'trace' stream, and for tests to make assertions on its contents # # A trace stream looks like a regular stream: # write: int # index at which writes go # read: int # index that we've read until # data: (array byte) # prefixed by size as usual # Usually the trace stream will be in a separate segment set aside for the purpose. # # primitives for operating on traces (arguments in quotes): # - initialize-trace-stream: populates Trace-stream with a new segment of the given 'size' # - trace: adds a 'line' to Trace-stream # - check-trace-contains: scans from Trace-stream's start for a matching 'line', prints a 'message' to stderr on failure # - check-trace-scans-to: scans from Trace-stream's read pointer for a matching 'line', prints a 'message' to stderr on failure == data Trace-stream: # (addr stream byte) # TODO: make this a handle 0/imm32 Trace-segment: 0/imm32/curr 0/imm32/limit # Fake trace-stream for tests. # Also illustrates the layout of the real trace-stream (segment). _test-trace-stream: # (stream byte) # current write index 0/imm32 # current read index 0/imm32 # size 8/imm32 # data 00 00 00 00 00 00 00 00 # 8 bytes == 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 # Allocate a new segment for the trace stream, initialize its size, and save its address to Trace-stream. # The Trace-stream segment will consist of variable-length lines separated by newlines (0x0a) initialize-trace-stream: # n: 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 51/push-ecx # ecx = n 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 8/disp8 . # copy *(ebp+8) to ecx # Trace-segment = new-segment(n) # . . push args 68/push Trace-segment/imm32 51/push-ecx # . . call e8/call new-segment/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # copy Trace-segment->curr to *Trace-stream 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 0/r32/eax Trace-segment/disp32 # copy *Trace-segment to eax #? # watch point to catch Trace-stream leaks #? $watch-1: 89/copy 0/mod/indirect 5/rm32/.disp32 . . 0/r32/eax Trace-stream/disp32 # copy eax to *Trace-stream # Trace-stream->size = n - 12 # . ecx -= 12 81 5/subop/subtract 3/mod/direct 1/rm32/ecx . . . . . 0xc/imm32 # subtract from ecx # . Trace-stream->size = ecx 89/copy 1/mod/*+disp8 0/rm32/eax . . . 1/r32/ecx 8/disp8 . # copy ecx to *(eax+8) $initialize-trace-stream:end: # . restore registers 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 # Append a string to the given trace stream. # Silently give up if it's already full. Or truncate the string if there isn't enough room. trace: # line: (addr array 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 52/push-edx 53/push-ebx 56/push-esi 57/push-edi # var edi: (addr stream byte) = *Trace-stream 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 7/r32/edi Trace-stream/disp32 # copy *Trace-stream to edi # esi = line 8b/copy 1/mod/*+disp8 5/rm32/ebp . . 6/r32/esi 8/disp8 . # copy *(ebp+8) to esi # var ecx: int = t->write 8b/copy 0/mod/indirect 7/rm32/edi . . . 1/r32/ecx . . # copy *edi to ecx # var edx: int = t->size 8b/copy 1/mod/*+disp8 7/rm32/edi . . . 2/r32/edx 8/disp8 . # copy *(edi+8) to edx # eax = _append-3(&t->data[t->write], &t->data[t->size], line) # . . push line 56/push-esi # . . push &t->data[t->size] 8d/copy-address 1/mod/*+disp8 4/rm32/sib 7/base/edi 2/index/edx . 3/r32/ebx 0xc/disp8 . # copy edi+edx+12 to ebx 53/push-ebx # . . push &t->data[t->write] 8d/copy-address 1/mod/*+disp8 4/rm32/sib 7/base/edi 1/index/ecx . 3/r32/ebx 0xc/disp8 . # copy edi+ecx+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 # if (eax == 0) return 3d/compare-eax-and 0/imm32 74/jump-if-= $trace:end/disp8 # t->write += eax 01/add 0/mod/indirect 7/rm32/edi . . . 0/r32/eax . . # add eax to *edi # refresh ecx = t->write 8b/copy 0/mod/indirect 7/rm32/edi . . . 1/r32/ecx . . # copy *edi to ecx # eax = _append-3(&t->data[t->write], &t->data[t->size], line) # . . push line 68/push Newline/imm32 # . . push &t->data[t->size] 8d/copy-address 1/mod/*+disp8 4/rm32/sib 7/base/edi 2/index/edx . 3/r32/ebx 0xc/disp8 . # copy edi+edx+12 to ebx 53/push-ebx # . . push &t->data[t->write] 8d/copy-address 1/mod/*+disp8 4/rm32/sib 7/base/edi 1/index/ecx . 3/r32/ebx 0xc/disp8 . # copy edi+ecx+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 # t->write += eax 01/add 0/mod/indirect 7/rm32/edi . . . 0/r32/eax . . # add eax to *edi $trace:end: # . 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 # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return test-trace-single: # push *Trace-stream ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 . . . Trace-stream/disp32 # push *Trace-stream # *Trace-stream = _test-trace-stream b8/copy-to-eax _test-trace-stream/imm32 89/copy 0/mod/indirect 5/rm32/.disp32 . . 0/r32/eax Trace-stream/disp32 # copy eax to *Trace-stream # clear-trace-stream() e8/call clear-trace-stream/disp32 # trace("Ab") # . . push args 68/push "Ab"/imm32 # . . call e8/call trace/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp # check-ints-equal(*_test-trace-stream->data, 41/A 62/b 0a/newline 00, msg) # . . push args 68/push "F - test-trace-single"/imm32 68/push 0x0a6241/imm32/Ab-newline # . . push *_test-trace-stream->data b8/copy-to-eax _test-trace-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 . . .
# 32-bit fixed-point number, with 6 bits of precision.

type LayoutUnit* = distinct int32

func `==`*(a, b: LayoutUnit): bool {.borrow.}
func `<`*(a, b: LayoutUnit): bool {.borrow.}
func `<=`*(a, b: LayoutUnit): bool {.borrow.}
func `+`*(a, b: LayoutUnit): LayoutUnit {.borrow.}
func `+=`*(a: var LayoutUnit, b: LayoutUnit) {.borrow.}
func `-`*(a, b: LayoutUnit): LayoutUnit {.borrow.}
func `-`*(a: LayoutUnit): LayoutUnit {.borrow.}
func `-=`*(a: var LayoutUnit, b: LayoutUnit) {.borrow.}
func `*`*(a, b: LayoutUnit): LayoutUnit {.inline.} =
  LayoutUnit((int32(a) * int32(b)) shr 6)
func `*=`*(a: var LayoutUnit, b: LayoutUnit) {.inline.} =
  a = a * b
func `/`*(a, b: LayoutUnit): LayoutUnit {.inline.} =
  let a64 = int64(a)
  let b64 = int64(b)
  LayoutUnit(cast[int32](((a64 shl 12) div b64) shr 6))
func `/=`*(a: var LayoutUnit, b: LayoutUnit) {.inline.} =
  a = a / b
func `div`*(a, b: LayoutUnit): LayoutUnit {.inline.} =
  a / b

func toInt*(a: LayoutUnit): int =
  return int32(a) shr 6

converter toLayoutUnit*(a: int32): LayoutUnit =
  return LayoutUnit(a shl 6)

converter toLayoutUnit*(a: int64): LayoutUnit =
  return toLayoutUnit(cast[int32](a))

converter toLayoutUnit*(a: int): LayoutUnit =
  return toLayoutUnit(cast[int32](a))

converter toLayoutUnit*(a: float64): LayoutUnit =
  if unlikely(a == Inf):
    return LayoutUnit(high(int32))
  elif unlikely(a == -Inf):
    return LayoutUnit(low(int32))
  return LayoutUnit(int32(a * 64))

func toFloat64*(a: LayoutUnit): float64 =
  return float64(int32(a)) / 64

func `$`*(a: LayoutUnit): string =
  $toFloat64(a)

func min*(a, b: LayoutUnit): LayoutUnit {.borrow.}
func max*(a, b: LayoutUnit): LayoutUnit {.borrow.}
func clamp*(x, a, b: LayoutUnit): LayoutUnit {.borrow.}

func round*(a: LayoutUnit; prec: int): LayoutUnit =
  return (a div prec).toInt * prec
read] 8d/copy-address 0/mod/indirect 4/rm32/sib 3/base/ebx 0/index/eax . 7/r32/edi . . # copy ebx+eax to edi $next-line-matches?:loop: # if (currl >= maxl) break 39/compare 3/mod/direct 6/rm32/esi . . . 1/r32/ecx . . # compare esi and ecx 73/jump-if-addr>= $next-line-matches?:break/disp8 # if (currt >= maxt) return false # . eax = false b8/copy-to-eax 0/imm32/false 39/compare 3/mod/direct 7/rm32/edi . . . 2/r32/edx . . # compare edi and edx 73/jump-if-addr>= $next-line-matches?:end/disp8 # if (*currt != *currl) return false 31/xor 3/mod/direct 0/rm32/eax . . . 0/r32/eax . . # clear eax 31/xor 3/mod/direct 3/rm32/eax . . . 3/r32/eax . . # clear ebx # . eax: byte = *currt 8a/copy-byte 0/mod/indirect 7/rm32/edi . . 0/r32/eax . . # copy *edi to eax # . ebx: byte = *currl 8a/copy-byte 0/mod/indirect 6/rm32/esi . . 3/r32/ebx . . # copy *esi to ebx # . eax >= ebx 39/compare 3/mod/direct 0/rm32/eax . . . 3/r32/ebx . . # compare eax and ebx # . eax = false b8/copy-to-eax 0/imm32/false 75/jump-if-!= $next-line-matches?:end/disp8 # ++currt 47/increment-edi # ++currl 46/increment-esi eb/jump $next-line-matches?:loop/disp8 $next-line-matches?:break: # return *currt == '\n' 31/xor 3/mod/direct 0/rm32/eax . . . 0/r32/eax . . # clear eax # . eax: byte = *currt 8a/copy-byte 0/mod/indirect 7/rm32/edi . . 0/r32/eax . . # copy *edi to eax 3d/compare-eax-and 0xa/imm32/newline # . eax = false b8/copy-to-eax 1/imm32/true 74/jump-if-= $next-line-matches?:end/disp8 b8/copy-to-eax 0/imm32/true $next-line-matches?:end: # . restore registers 5f/pop-to-edi 5e/pop-to-esi 5b/pop-to-ebx 5a/pop-to-edx 59/pop-to-ecx # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return test-next-line-matches?-no-match-1: # next line of "ABABA" does not match "blah blah" # . eax = next-line-matches?(_test-stream-line-ABABA, "blah blah") # . . push args 68/push "blah blah"/imm32 68/push _test-stream-line-ABABA/imm32 # . . call e8/call next-line-matches?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # . check-ints-equal(eax, 0, msg) # . . push args 68/push "F - test-next-line-matches?-no-match-1"/imm32 68/push 0/imm32 50/push-eax # . . call e8/call check-ints-equal/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp c3/return test-next-line-matches?-no-match-2: # next line of "ABABA" does not match "" # . eax = next-line-matches?(_test-stream-line-ABABA, "") # . . push args 68/push ""/imm32 68/push _test-stream-line-ABABA/imm32 # . . call e8/call next-line-matches?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # . check-ints-equal(eax, 0, msg) # . . push args 68/push "F - test-next-line-matches?-no-match-2"/imm32 68/push 0/imm32 50/push-eax # . . call e8/call check-ints-equal/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp c3/return test-next-line-matches?-no-match-3: # next line of "ABABA" does not match "AA" # . eax = next-line-matches?(_test-stream-line-ABABA, "AA") # . . push args 68/push "AA"/imm32 68/push _test-stream-line-ABABA/imm32 # . . call e8/call next-line-matches?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # . check-ints-equal(eax, 0, msg) # . . push args 68/push "F - test-next-line-matches?-no-match-3"/imm32 68/push 0/imm32 50/push-eax # . . call e8/call check-ints-equal/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp c3/return test-next-line-matches?-match: # next line of "ABABA" matches "ABABA" # . eax = next-line-matches?(_test-stream-line-ABABA, "ABABA") # . . push args 68/push "ABABA"/imm32 68/push _test-stream-line-ABABA/imm32 # . . call e8/call next-line-matches?/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp # . check-ints-equal(eax, 1, msg) # . . push args 68/push "F - test-next-line-matches?-match"/imm32 68/push 1/imm32 50/push-eax # . . call e8/call check-ints-equal/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp c3/return # move t->read to _after_ next newline skip-next-line: # t: (addr stream byte) # pseudocode: # max = &t->data[t->write] # i = t->read # curr = &t->data[t->read] # while true # if (curr >= max) break # ++i # if (*curr == '\n') break # ++curr # t->read = i # # . 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 52/push-edx 53/push-ebx # ecx = t 8b/copy 1/mod/*+disp8 5/rm32/ebp . . 1/r32/ecx 8/disp8 . # copy *(ebp+8) to ecx # edx = t->data 8d/copy-address 1/mod/*+disp8 1/rm32/ecx . . . 2/r32/edx 0xc/disp8 . # copy ecx+12 to edx # eax = t->write 8b/copy 0/mod/indirect 1/rm32/ecx . . . 0/r32/eax . . # copy *ecx to eax # var max/ebx: (addr byte) = &t->data[t->write] 8d/copy-address 0/mod/indirect 4/rm32/sib 2/base/edx 0/index/eax . 3/r32/ebx . . # copy edx+eax to ebx # eax = t->read 8b/copy 1/mod/*+disp8 1/rm32/ecx . . . 0/r32/eax 4/disp8 . # copy *(ecx+4) to edx # var curr/ecx: (addr byte) = &t->data[t->read] 8d/copy-address 0/mod/indirect 4/rm32/sib 2/base/edx 0/index/eax . 1/r32/ecx . . # copy edx+eax to ecx # var i/edx: int = t->read 89/copy 3/mod/direct 2/rm32/edx . . . 0/r32/eax . . # copy eax to edx $skip-next-line:loop: # if (curr >= max) break 39/compare 3/mod/direct 1/rm32/ecx . . . 3/r32/ebx . . # compare ecx and ebx 73/jump-if-addr>= $skip-next-line:end/disp8 # ++i 42/increment-edx # if (*curr == '\n') break 31/xor 3/mod/direct 0/rm32/eax . . . 0/r32/eax . . # clear eax 8a/copy-byte 0/mod/indirect 1/rm32/ecx . . . 0/r32/eax . . # copy *ecx to eax 3d/compare-eax-and 0a/imm32/newline 74/jump-if-= $skip-next-line:end/disp8 # ++curr 41/increment-ecx # loop eb/jump $skip-next-line:loop/disp8 $skip-next-line:end: # ecx = t 8b/copy 1/mod/*+disp8 5/rm32/ebp . . 1/r32/ecx 8/disp8 . # copy *(ebp+8) to ecx # t->read = i 89/copy 1/mod/*+disp8 1/rm32/ecx . . . 2/r32/edx 4/disp8 . # copy edx to *(ecx+4) # . restore registers 5b/pop-to-ebx 5a/pop-to-edx 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-skip-next-line-empty: # skipping next line in empty stream leaves read pointer at 0 # . skip-next-line(_test-stream-empty) # . . push args 68/push _test-stream-empty/imm32 # . . call e8/call skip-next-line/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp # . check-ints-equal(_test-stream-empty->read, 0, msg) # . . push args 68/push "F - test-skip-next-line-empty"/imm32 68/push 0/imm32 b8/copy-to-eax _test-stream-empty/imm32 8b/copy 1/mod/*+disp8 0/rm32/eax . . . 0/r32/eax 4/disp8 . # copy *(eax+4) to eax 50/push-eax # . . call e8/call check-ints-equal/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp c3/return test-skip-next-line-filled: # skipping next line increments read pointer by length of line + 1 (for newline) # . skip-next-line(_test-stream-filled) # . . push args 68/push _test-stream-filled/imm32 # . . call e8/call skip-next-line/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp # . check-ints-equal(_test-stream-filled->read, 5, msg) # . . push args 68/push "F - test-skip-next-line-filled"/imm32 68/push 5/imm32 b8/copy-to-eax _test-stream-filled/imm32 8b/copy 1/mod/*+disp8 0/rm32/eax . . . 0/r32/eax 4/disp8 . # copy *(eax+4) to eax 50/push-eax # . . call e8/call check-ints-equal/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp c3/return clear-trace-stream: # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # clear-stream(*Trace-stream) # . . push args ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 . . . Trace-stream/disp32 # push *Trace-stream # . . call e8/call clear-stream/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp $clear-trace-stream:end: # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return # - helpers # 3-argument variant of _append _append-3: # out: (addr byte), outend: (addr byte), s: (addr array byte) -> num_bytes_appended/eax # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # . save registers 51/push-ecx # eax = _append-4(out, outend, &s->data[0], &s->data[s->size]) # . . push &s->data[s->size] 8b/copy 1/mod/*+disp8 5/rm32/ebp . . 0/r32/eax 0x10/disp8 . # copy *(ebp+16) to eax 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 51/push-ecx # . . push &s->data[0] 8d/copy-address 1/mod/*+disp8 0/rm32/eax . . . 1/r32/ecx 4/disp8 . # copy eax+4 to ecx 51/push-ecx # . . push outend ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0xc/disp8 . # push *(ebp+12) # . . push out ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8) # . . call e8/call _append-4/disp32 # . . discard args 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0x10/imm32 # add to esp $_append-3:end: # . restore registers 59/pop-to-ecx # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return # 4-argument variant of _append _append-4: # out: (addr byte), outend: (addr byte), in: (addr byte), inend: (addr byte) -> num_bytes_appended/eax: int # . prologue 55/push-ebp 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp # . save registers 51/push-ecx 52/push-edx 53/push-ebx 56/push-esi 57/push-edi # num_bytes_appended = 0 b8/copy-to-eax 0/imm32 # edi = out 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 7/r32/edi 8/disp8 . # copy *(ebp+8) to edi # edx = outend 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 2/r32/edx 0xc/disp8 . # copy *(ebp+12) to edx # esi = in 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 6/r32/esi 0x10/disp8 . # copy *(ebp+16) to esi # ecx = inend 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 0x14/disp8 . # copy *(ebp+20) to ecx $_append-4:loop: # if (in >= inend) break 39/compare 3/mod/direct 6/rm32/esi . . . 1/r32/ecx . . # compare esi with ecx 73/jump-if-addr>= $_append-4:end/disp8 # if (out >= outend) abort # just to catch test failures fast 39/compare 3/mod/direct 7/rm32/edi . . . 2/r32/edx . . # compare edi with edx 73/jump-if-addr>= $_append-4:abort/disp8 # *out = *in 8a/copy-byte 0/mod/indirect 6/rm32/esi . . . 3/r32/BL . . # copy byte at *esi to BL 88/copy-byte 0/mod/indirect 7/rm32/edi . . . 3/r32/BL . . # copy byte at BL to *edi # ++num_bytes_appended 40/increment-eax # ++in 46/increment-esi # ++out 47/increment-edi eb/jump $_append-4:loop/disp8 $_append-4:end: # . restore registers 5f/pop-to-edi 5e/pop-to-esi 5b/pop-to-ebx 5a/pop-to-edx 59/pop-to-ecx # . epilogue 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 5d/pop-to-ebp c3/return $_append-4:abort: # . _write(2/stderr, error) # . . push args 68/push "stream overflow\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 e8/call syscall_exit/disp32 # never gets here == data _test-stream-line-ABABA: # (stream byte) # write 8/imm32 # read 0/imm32 # size 8/imm32 # data 41 42 41 42 41 0a 00 00 # 8 bytes _test-stream-empty: # (stream byte) # write 0/imm32 # read 0/imm32 # size 8/imm32 # data 00 00 00 00 00 00 00 00 # 8 bytes _test-stream-filled: # (stream byte) # write 8/imm32 # read 0/imm32 # size 8/imm32 # data 41 41 41 41 0a 41 41 41 # 8 bytes # . . vim:nowrap:textwidth=0