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|
## Port of https://github.com/akkartik/crenshaw/blob/master/tutor2.1.pas
# Corresponds to the section "single digits" in https://compilers.iecc.com/crenshaw/tutor2.txt
#
# To run (from the subx directory):
# $ ./subx translate *.subx apps/crenshaw2-1.subx -o crenshaw2-1
# $ echo '3' |./subx run apps/crenshaw2-1
# Expected output (not working yet):
# # syscall(exit, 3)
# bb/copy-to-EBX 3/imm32
# b8/copy-to-EAX 1/imm32/exit
# cd/syscall 0x80/imm8
#
# To run the generated output:
# $ echo '3' |./subx run apps/crenshaw2-1 > z1.subx
# $ ./subx translate z1.subx -o z1
# $ ./subx run z1
# $ echo $?
# 3
#
# Stdin must contain just a single hex digit. Other input will print an error:
# $ echo 'xyz' |./subx run apps/crenshaw2-1
# Error: integer expected
#
# Names in this file sometimes follow Crenshaw's original rather than my usual
# naming conventions.
== code
# instruction effective address operand 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:
# prolog
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# if (argc > 1)
81 7/subop/compare 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0/disp8 1/imm32 # compare *EBP
7e/jump-if-lesser-or-equal $run-main/disp8
# and if (argv[1] == "test")
# push args
68/push "test"/imm32
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x8/disp8 . # push *(EBP+8)
# call
e8/call kernel-string-equal/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# check result
3d/compare-EAX 1/imm32
75/jump-if-not-equal $run-main/disp8
# then return run-tests()
e8/call run-tests/disp32
8b/copy 0/mod/indirect 5/rm32/.disp32 . . 3/r32/EBX Num-test-failures/disp32 # copy *Num-test-failures to EBX
eb/jump $main:end/disp8
$run-main:
# allocate space for an exit-descriptor
# var ed/EAX : (address exit-descriptor)
81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # subtract from ESP
8d/copy-address 0/mod/indirect 4/rm32/sib 4/base/ESP 4/index/none . 0/r32/EAX . . # copy ESP to EAX
# clear ed->target (so we really exit)
c7/copy 0/mod/direct 0/rm32/EAX . . . . . 0/imm32 # copy to *EAX
# expected(ed, 2/stderr, "integer")
# push args
68/push "integer"/imm32
68/push 2/imm32/stderr
50/push-EAX
# call
e8/call expected/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# syscall(exit, 0)
bb/copy-to-EBX 0/imm32
$main:end:
b8/copy-to-EAX 1/imm32/exit
cd/syscall 0x80/imm8
# Read a sequence of digits into 'out'. Abort if there are none, or if there
# are too many to fit in 'out'.
# Input comes from the global variable 'Look' (first byte) and the argument
# 'in' (rest).
get-num: # in : (address buffered-file), out : (address stream), err : fd or (address stream), ed : (address exit-descriptor) -> <void>
# pseudocode:
# if !is-digit?(Look) expected(ed, err, "integer")
# do
# if Look > 0xff
# write(err, "Error: tried to write more than one byte\n")
# stop(ed, 1)
# if out.write >= out.length
# write(err, "Error: too many digits in number\n")
# stop(ed, 1)
# out.data[out.write] = LSB(Look)
# ++out.write
# Look = get-char(in)
# while is-digit?(Look)
# This is complicated because I don't want to hard-code the error strategy in
# a general helper like write-byte. Maybe I should just create a local helper.
#
# within the loop we'll try to keep things in registers:
# ESI : in
# EDI : out
# EAX : temp
# ECX : out->write
# EDX : out->length
# EBX : temp2
# We can't allocate Look to a register because it gets written implicitly in
# get-char in each iteration of the loop. (Thereby demonstrating that it's
# not the right interface for us. But we'll keep it just to follow Crenshaw.)
#
# prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# EAX = is-digit?(Look)
# push args
ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 . . . Look/disp32 . # push *Look
# call
e8/call is-digit?/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# if EAX == 0 error
3d/compare-EAX 0/imm32
75/jump-if-not-equal $get-num:main/disp8
# expected(ed, err, "integer")
# push args
68/push "integer"/imm32
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x10/disp8 . # push *(EBP+16)
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x14/disp8 . # push *(EBP+20)
# call
e8/call expected/disp32 # never returns
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
$get-num:main:
# save registers
50/push-EAX
51/push-ECX
52/push-EDX
53/push-EBX
56/push-ESI
57/push-EDI
# read necessary variables to registers
# ESI = in
8b/copy 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . 6/r32/ESI 8/disp8 . # copy *(EBP+8) to ESI
# EDI = out
8b/copy 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . 7/r32/EDI 0xc/disp8 . # copy *(EBP+12) to EDI
# ECX = out->write
8b/copy 0/mod/indirect 7/rm32/EDI . . . 1/r32/ECX . . # copy *EDI to ECX
# EDX = out->length
8b/copy 1/mod/*+disp8 7/rm32/EDI . . . 2/r32/EDX 8/disp8 . # copy *(EDI+8) to EDX
$get-num:loop:
# if Look > 0xff error
8b/copy 0/mod/indirect 5/rm32/.disp32 . . 0/r32/EAX Look/disp32 . # copy *Look to EAX
3d/compare-EAX 0xff/imm32
7e/jump-if-lesser-or-equal $get-num:loop-stage2/disp8
# error(ed, err, "get-num: tried to write too large a value into a single byte") # TODO: show value being printed
# push args
68/push "get-num: tried to write too large a value into a single byte"/imm32
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x10/disp8 . # push *(EBP+16)
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x14/disp8 . # push *(EBP+20)
# call
e8/call error/disp32 # never returns
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
$get-num:loop-stage2:
# if out->write >= out->length error
3b/compare 3/mod/direct 1/rm32/ECX . . . 2/r32/EDX . . # compare EDX with ECX
7d/jump-if-lesser $get-num:loop-stage3/disp8
# error(ed, err, "get-num: too many digits in number") # TODO: show full number
# push args
68/push "get-num: too many digits in number"/imm32
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x10/disp8 . # push *(EBP+16)
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x14/disp8 . # push *(EBP+20)
# call
e8/call error/disp32 # never returns
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
$get-num:loop-stage3:
# out->data[out->write] = LSB(Look)
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
8b/copy 0/mod/indirect 5/rm32/.disp32 . . 0/r32/EAX Look/disp32 . # copy *Look to EAX
88/copy-byte 0/mod/indirect 3/rm32/EBX . . . 0/r32/AL . . # copy byte at AL to *EBX
# ++out->write
41/increment-ECX
# Look = get-char(in)
# push args
56/push-ESI
# call
e8/call get-char/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# EAX = is-digit?(Look)
# push args
ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 . . . Look/disp32 . # push *Look
# call
e8/call is-digit?/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# if EAX loop
3d/compare-EAX 0/imm32
75/jump-if-not-equal $get-num:loop/disp8
$get-num:loop-end:
# persist necessary variables from registers
89/copy 0/mod/indirect 7/rm32/EDI . . . 1/r32/ECX . . # copy ECX to *EDI
# 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
# epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
test-get-num-reads-single-digit:
## check that get-num returns first character if it's a digit
# This test uses exit-descriptors. Use EBP for setting up local variables.
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
## clear all streams
# clear-stream(_test-stream)
# push args
68/push _test-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-buffered-file+4)
# push args
b8/copy-to-EAX _test-buffered-file/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
# 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-error-stream)
# push args
68/push _test-error-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 'in'
# write(_test-stream, "3")
# push args
68/push "3"/imm32
68/push _test-stream/imm32
# call
e8/call write/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
## initialize exit-descriptor 'ed'
# allocate on stack
# var ed/EAX : (address exit-descriptor)
81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # subtract from ESP
8d/copy-address 0/mod/indirect 4/rm32/sib 4/base/ESP 4/index/none . 0/r32/EAX . . # copy ESP to EAX
# size the exit-descriptor for the call to get-num below
# tailor-exit-descriptor(ed, 16)
# push args
68/push 0x10/imm32/nbytes-of-args-for-get-num
50/push-EAX/ed
# call
e8/call tailor-exit-descriptor/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
## prime the pump
# get-char(_test-buffered-file)
# push args
68/push _test-buffered-file/imm32
# call
e8/call get-char/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
## get-num(in, out, err, ed)
# push args
50/push-EAX/ed
68/push _test-error-stream/imm32
68/push _test-output-stream/imm32
68/push _test-buffered-file/imm32
# call
e8/call get-num/disp32
## registers except ESP may be clobbered at this point
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0x10/imm32 # add to ESP
# check-ints-equal(*_test-output-stream.data, '3')
# push args
68/push "F - test-get-num-reads-single-digit"/imm32
68/push 0x33/imm32
b8/copy-to-EAX _test-output-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 . . . . . 0xc/imm32 # add to ESP
# reclaim locals
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
5d/pop-to-EBP
c3/return
test-get-num-aborts-on-non-digit-in-Look:
## check that get-num returns first character if it's a digit
# This test uses exit-descriptors. Use EBP for setting up local variables.
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
## clear all streams
# clear-stream(_test-stream)
# push args
68/push _test-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-buffered-file+4)
# push args
b8/copy-to-EAX _test-buffered-file/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
# 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-error-stream)
# push args
68/push _test-error-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 'in'
# write(_test-stream, "3")
# push args
68/push "3"/imm32
68/push _test-stream/imm32
# call
e8/call write/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
## initialize exit-descriptor 'ed'
# allocate on stack
# var ed/EAX : (address exit-descriptor)
81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # subtract from ESP
8d/copy-address 0/mod/indirect 4/rm32/sib 4/base/ESP 4/index/none . 0/r32/EAX . . # copy ESP to EAX
# size the exit-descriptor for the call to get-num below
# tailor-exit-descriptor(ed, 16)
# push args
68/push 0x10/imm32/nbytes-of-args-for-get-num
50/push-EAX/ed
# call
e8/call tailor-exit-descriptor/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
## don't initialize Look
## get-num(in, out, err, ed)
# push args
50/push-EAX/ed
68/push _test-error-stream/imm32
68/push _test-output-stream/imm32
68/push _test-buffered-file/imm32
# call
e8/call get-num/disp32
## registers except ESP may be clobbered at this point
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0x10/imm32 # add to ESP
## check that get-num tried to call exit(1)
# check-ints-equal(ed->value, 2, msg) # i.e. stop was called with value 1
# push args
68/push "F - test-get-num-aborts-on-non-digit-in-Look"/imm32
68/push 2/imm32
# push ed->value
ff 6/subop/push 1/mod/*+disp8 0/rm32/EAX . . . . 4/disp8 . # push *(EAX+4)
# call
e8/call check-ints-equal/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP
# reclaim locals
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
5d/pop-to-EBP
c3/return
test-get-num-reads-multiple-digits:
## check that get-num returns all initial digits until it encounters a non-digit
# This test uses exit-descriptors. Use EBP for setting up local variables.
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
## clear all streams
# clear-stream(_test-stream)
# push args
68/push _test-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-buffered-file+4)
# push args
b8/copy-to-EAX _test-buffered-file/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
# 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-error-stream)
# push args
68/push _test-error-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 'in'
# write(_test-stream, "3456 x")
# push args
68/push "3456"/imm32
68/push _test-stream/imm32
# call
e8/call write/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
## initialize exit-descriptor 'ed'
# allocate on stack
# var ed/EAX : (address exit-descriptor)
81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # subtract from ESP
8d/copy-address 0/mod/indirect 4/rm32/sib 4/base/ESP 4/index/none . 0/r32/EAX . . # copy ESP to EAX
# size the exit-descriptor for the call to get-num below
# tailor-exit-descriptor(ed, 16)
# push args
68/push 0x10/imm32/nbytes-of-args-for-get-num
50/push-EAX/ed
# call
e8/call tailor-exit-descriptor/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
## prime the pump
# get-char(_test-buffered-file)
# push args
68/push _test-buffered-file/imm32
# call
e8/call get-char/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
## get-num(in, out, err, ed)
# push args
50/push-EAX/ed
68/push _test-error-stream/imm32
68/push _test-output-stream/imm32
68/push _test-buffered-file/imm32
# call
e8/call get-num/disp32
## registers except ESP may be clobbered at this point
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0x10/imm32 # add to ESP
# check-ints-equal(*_test-output-stream.data, '3456')
# push args
68/push "F - test-get-num-reads-multiple-digits"/imm32
68/push 0x36353433/imm32
b8/copy-to-EAX _test-output-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 . . . . . 0xc/imm32 # add to ESP
# reclaim locals
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
5d/pop-to-EBP
c3/return
test-get-num-reads-multiple-digits-followed-by-nondigit:
## check that get-num returns all initial digits until it encounters a non-digit
# This test uses exit-descriptors. Use EBP for setting up local variables.
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
## clear all streams
# clear-stream(_test-stream)
# push args
68/push _test-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-buffered-file+4)
# push args
b8/copy-to-EAX _test-buffered-file/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
# 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-error-stream)
# push args
68/push _test-error-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 'in'
# write(_test-stream, "3456 x")
# push args
68/push "3456 x"/imm32
68/push _test-stream/imm32
# call
e8/call write/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
## initialize exit-descriptor 'ed'
# allocate on stack
# var ed/EAX : (address exit-descriptor)
81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # subtract from ESP
8d/copy-address 0/mod/indirect 4/rm32/sib 4/base/ESP 4/index/none . 0/r32/EAX . . # copy ESP to EAX
# size the exit-descriptor for the call to get-num below
# tailor-exit-descriptor(ed, 16)
# push args
68/push 0x10/imm32/nbytes-of-args-for-get-num
50/push-EAX/ed
# call
e8/call tailor-exit-descriptor/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
## prime the pump
# get-char(_test-buffered-file)
# push args
68/push _test-buffered-file/imm32
# call
e8/call get-char/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
## get-num(in, out, err, ed)
# push args
50/push-EAX/ed
68/push _test-error-stream/imm32
68/push _test-output-stream/imm32
68/push _test-buffered-file/imm32
# call
e8/call get-num/disp32
## registers except ESP may be clobbered at this point
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0x10/imm32 # add to ESP
# check-ints-equal(*_test-output-stream.data, '3456')
# push args
68/push "F - test-get-num-reads-multiple-digits-followed-by-nondigit"/imm32
68/push 0x36353433/imm32
b8/copy-to-EAX _test-output-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 . . . . . 0xc/imm32 # add to ESP
# reclaim locals
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
5d/pop-to-EBP
c3/return
## helpers
# write(f, "Error: "+s+" expected\n") then stop(ed, 1)
expected: # ed : (address exit-descriptor), f : fd or (address stream), s : (address array byte) -> <void>
# prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# write(f, "Error: ")
# push args
68/push "Error: "/imm32
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0xc/disp8 . # push *(EBP+12)
# call
e8/call write/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# write(f, s)
# push args
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x10/disp8 . # push *(EBP+16)
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0xc/disp8 . # push *(EBP+12)
# call
e8/call write/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# write(f, " expected")
# push args
68/push " expected"/imm32
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0xc/disp8 . # push *(EBP+12)
# call
e8/call write/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# write(f, Newline)
# push args
68/push Newline/imm32
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0xc/disp8 . # push *(EBP+12)
# call
e8/call write/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# stop(ed, 1)
# push args
68/push 1/imm32
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 8/disp8 . # push *(EBP+8)
# call
e8/call stop/disp32
## should never get past this point
# epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
# write(f, "Error: "+s+"\n") then stop(ed, 1)
error: # ed : (address exit-descriptor), f : fd or (address stream), s : (address array byte) -> <void>
# prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# write(f, "Error: ")
# push args
68/push "Error: "/imm32
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0xc/disp8 . # push *(EBP+12)
# call
e8/call write/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# write(f, s)
# push args
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x10/disp8 . # push *(EBP+16)
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0xc/disp8 . # push *(EBP+12)
# call
e8/call write/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# write(f, Newline)
# push args
68/push Newline/imm32
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0xc/disp8 . # push *(EBP+12)
# call
e8/call write/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP
# stop(ed, 1)
# push args
68/push 1/imm32
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 8/disp8 . # push *(EBP+8)
# call
e8/call stop/disp32
## should never get past this point
# epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
# read a byte from 'f', and store it in 'Look'
get-char: # f : (address buffered-file) -> <void>
# prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# save registers
50/push-EAX
# read-byte(f)
# push args
ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x8/disp8 . # push *(EBP+8)
# call
e8/call read-byte/disp32
# discard args
81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP
# save EAX to Look
89/copy 0/mod/indirect 5/rm32/.disp32 . . 0/r32/EAX Look/disp32 . # copy EAX to *Look
# restore registers
58/pop-to-EAX
# epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
is-digit?: # c : int -> bool/EAX
# prolog
55/push-EBP
89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP
# EAX = false
b8/copy-to-EAX 0/imm32
# if c < '0' return false
81 7/subop/compare 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x8/disp8 0x30/imm32 # compare *(EBP+8)
7c/jump-if-lesser $is-digit?:end/disp8
# if c > '9' return false
81 7/subop/compare 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x8/disp8 0x39/imm32 # compare *(EBP+8)
7f/jump-if-greater $is-digit?:end/disp8
# otherwise return true
b8/copy-to-EAX 1/imm32
$is-digit?:end:
# epilog
89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP
5d/pop-to-EBP
c3/return
== data
Look:
00 00 00 00
_test-output-stream:
# 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
_test-error-stream:
# 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
# vim:nowrap:textwidth=0
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