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|
# The Mu computer's level-2 language, also called Mu.
# http://akkartik.name/post/mu-2019-2
#
# To run:
# $ ./ntranslate init.linux 0*.subx apps/mu.subx
# == Goals
# 1. Be memory safe. It should be impossible to corrupt the heap, or to create
# a bad pointer. (Requires strong type safety.)
# 2. Do as little as possible to achieve goal 1.
# - runtime checks to avoid complex static analysis
# - minimize impedance mismatch between source language and SubX target
# == Language description
# A program is a sequence of function definitions.
#
# Function example:
# fn foo n: int -> result/eax: int {
# ...
# }
#
# Functions consist of a name, optional inputs, optional outputs and a block.
#
# Function inputs and outputs are variables. All variables have a type and
# storage specifier. They can be placed either in memory (on the stack) or in
# one of 6 named registers.
# eax ecx edx ebx esi edi
# Variables in registers must be primitive 32-bit types.
# Variables not explicitly placed in a register are on the stack.
# Variables in registers need not have a name; in that case you refer to them
# directly by the register name.
#
# Function inputs are always passed in memory (on the stack), while outputs
# are always returned in registers.
#
# Blocks mostly consist of statements.
#
# Statements mostly consist of a name, optional inputs and optional outputs.
#
# Statement inputs are variables or literals. Variables need to specify type
# (and storage) the first time they're mentioned but not later.
#
# Statement outputs, like function outputs, must be variables in registers.
#
# Statement names must be either primitives or user-defined functions.
#
# Primitives can write to any register.
# User-defined functions only write to hard-coded registers. Outputs of each
# call must have the same registers as in the function definition.
#
# There are some other statement types:
# - blocks. Multiple statements surrounded by '{...}' and optionally
# prefixed with a label name and ':'
# - {
# ...
# }
# - foo: {
# ...
# }
#
# - variable definitions on the stack. E.g.:
# - var foo: int
# - var bar: (array int 3)
# There's no initializer; variables are automatically initialized.
#
# - variables definitions in a register. E.g.:
# - var foo/eax : int <- add bar 1
# The initializer is mandatory and must be a valid instruction that writes
# a single output to the right register. In practice registers will
# usually be either initialized by primitives or copied from eax.
# - var eax : int <- foo bar quux
# var floo/ecx : int <- copy eax
#
# Still todo:
# global variables
# heap allocations (planned name: 'handle')
# user-defined types: 'type' for structs, 'choice' for unions
# short-lived 'address' type for efficiently writing inside nested structs
#
# Formal types:
# A program is a linked list of functions
# A function contains:
# name: string
# inouts: linked list of vars <-- 'inouts' is more precise than 'inputs'
# data: (address var)
# next: (address list)
# outputs: linked list of vars
# data: (address var)
# next: (address list)
# body: block
# A var-type contains:
# name: string
# type: s-expression of type ids
# Statements are not yet fully designed.
# statement = var definition or simple statement or block
# simple statement:
# name: string
# inouts: linked list of vars
# outputs: linked list of vars
# block = linked list of statements
# == Translation
# Now that we know what the language looks like in the large, let's think
# about how translation happens from the bottom up. The interplay between
# variable scopes and statements using variables is the most complex aspect of
# translation.
#
# Assume that we maintain a 'functions' list while parsing source code. And a
# 'primitives' list is a global constant. Both these contain enough information
# to perform type-checking on function calls or primitive statements, respectively.
#
# Defining variables pushes them on a stack with the current block depth and
# enough information about their location (stack offset or register id).
# Starting a block increments the current block id.
# Each statement now has enough information to emit code for it.
# Ending a block is where the magic happens:
# pop all variables at the current block depth
# emit code to restore all register variables introduced at the current depth
# emit code to clean up all stack variables at the current depth (just increment esp)
# decrement the current block depth
#
# One additional check we'll need is to ensure that a variable in a register
# isn't shadowed by a different one. That may be worth a separate data
# structure but for now repeatedly scanning the var stack should suffice.
#
# Formal types:
# functions, primitives: linked list of info
# name: string
# inouts: linked list of vars
# outputs: linked list of vars
# live-vars: stack of vars
# var:
# name: string
# type: s-expression? Just a type id for now.
# block: int
# stack-offset: int (added to ebp)
# register-index: int
# 0-7 with usual meanings
# 8: any register
# At most one of stack-offset or register-index must be non-zero.
# When both are zero the variable is in eax (no way to refer to return
# address at ebp).
# A register-index of 8 designates a variable _template_. Only legal in
# formal parameters for primitives.
# == Compiling a single instruction
# Determine the function or primitive being called.
# If no matches, show all functions/primitives with the same name, along
# with reasons they don't match. (type and storage checking)
# It must be a function if:
# #outputs > 1, or
# #inouts > 2, or
# #inouts + #outputs > 2
# If it's a function, emit:
# (low-level-name <rm32 or imm32>...)
# Otherwise (it's a primitive):
# assert(#inouts <= 2 && #outs <= 1 && (#inouts + #outs) <= 2)
# emit opcode
# emit-rm32(inout[0])
# if out[0] exists: emit-r32(out[0])
# else if inout[1] is a literal: emit-imm32(inout[1])
# else: emit-rm32(inout[1])
# emit-rm32 and emit-r32 should check that the variable they intend is still
# available in the register.
# == Emitting a block
# Emit block name if necessary
# Emit '{'
# When you encounter a statement, emit it as above
# When you encounter a variable declaration
# emit any code needed for it (bzeros)
# push it on the var stack
# update register dict if necessary
# When you encounter '}'
# While popping variables off the var stack until block id changes
# Emit code needed to clean up the stack
# either increment esp
# or pop into appropriate register
# The rest is straightforward.
== data
Program: # (address function)
0/imm32
Function-name:
0/imm32
Function-subx-name:
4/imm32
Function-inouts: # (address list var)
8/imm32
Function-outputs: # (address list var)
0xc/imm32
Function-body: # (address block)
0x10/imm32
Function-next: # (address function)
0x14/imm32
Function-size:
0x18/imm32/24
Stmt-name:
0/imm32
Stmt-inouts:
4/imm32
Stmt-outputs:
8/imm32
Stmt-next:
0xc/imm32
Stmt-size:
0x10/imm32
Var-name:
0/imm32
Var-type:
4/imm32
Var-block:
8/imm32
Var-stack-offset:
0xc/imm32
Var-register-index:
0x10/imm32
Var-size:
0x14/imm32
== code
Entry:
# . prologue
89/<- %ebp 4/r32/esp
(new-segment Heap-size Heap)
# if (argv[1] == "test') run-tests()
{
# if (argc <= 1) break
81 7/subop/compare *ebp 1/imm32
7e/jump-if-lesser-or-equal break/disp8
# if (argv[1] != "test") break
(kernel-string-equal? *(ebp+8) "test") # => eax
3d/compare-eax-and 0/imm32
74/jump-if-equal break/disp8
#
(run-tests)
# syscall(exit, *Num-test-failures)
8b/-> *Num-test-failures 3/r32/ebx
eb/jump $mu-main:end/disp8
}
# otherwise convert Stdin
(convert-mu Stdin Stdout)
(flush Stdout)
# syscall(exit, 0)
bb/copy-to-ebx 0/imm32
$mu-main:end:
b8/copy-to-eax 1/imm32/exit
cd/syscall 0x80/imm8
convert-mu: # in : (address buffered-file), out : (address buffered-file)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
#
(parse-mu *(ebp+8))
(check-mu-types)
(emit-subx *(ebp+0xc))
$convert-mu:end:
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-convert-empty-input:
# empty input => empty output
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# setup
(clear-stream _test-input-stream)
(clear-stream _test-input-buffered-file->buffer)
(clear-stream _test-output-stream)
(clear-stream _test-output-buffered-file->buffer)
#
(convert-mu _test-input-buffered-file _test-output-buffered-file)
(flush _test-output-buffered-file)
(check-stream-equal _test-output-stream "" "F - test-convert-empty-input")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-convert-function-skeleton:
# empty function decl => function prologue and epilogue
# fn foo {
# }
# =>
# foo:
# # . prologue
# 55/push-ebp
# 89/<- %ebp 4/r32/esp
# # . epilogue
# 89/<- %esp 5/r32/ebp
# 5d/pop-to-ebp
# c3/return
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# setup
(clear-stream _test-input-stream)
(clear-stream _test-input-buffered-file->buffer)
(clear-stream _test-output-stream)
(clear-stream _test-output-buffered-file->buffer)
#
(write _test-input-stream "fn foo {\n")
(write _test-input-stream "}\n")
# convert
(convert-mu _test-input-buffered-file _test-output-buffered-file)
(flush _test-output-buffered-file)
#? # dump _test-output-stream {{{
#? (write 2 "^")
#? (write-stream 2 _test-output-stream)
#? (write 2 "$\n")
#? (rewind-stream _test-output-stream)
#? # }}}
# check output
(check-next-stream-line-equal _test-output-stream "foo:" "F - test-convert-function-skeleton/0")
(check-next-stream-line-equal _test-output-stream "# . prologue" "F - test-convert-function-skeleton/1")
(check-next-stream-line-equal _test-output-stream "55/push-ebp" "F - test-convert-function-skeleton/2")
(check-next-stream-line-equal _test-output-stream "89/<- %ebp 4/r32/esp" "F - test-convert-function-skeleton/3")
(check-next-stream-line-equal _test-output-stream "# . epilogue" "F - test-convert-function-skeleton/4")
(check-next-stream-line-equal _test-output-stream "89/<- %esp 5/r32/ebp" "F - test-convert-function-skeleton/5")
(check-next-stream-line-equal _test-output-stream "5d/pop-to-ebp" "F - test-convert-function-skeleton/6")
(check-next-stream-line-equal _test-output-stream "c3/return" "F - test-convert-function-skeleton/7")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-convert-multiple-function-skeletons:
# multiple functions correctly organized into a linked list
# fn foo {
# }
# fn bar {
# }
# =>
# foo:
# # . prologue
# 55/push-ebp
# 89/<- %ebp 4/r32/esp
# # . epilogue
# 89/<- %esp 5/r32/ebp
# 5d/pop-to-ebp
# c3/return
# bar:
# # . prologue
# 55/push-ebp
# 89/<- %ebp 4/r32/esp
# # . epilogue
# 89/<- %esp 5/r32/ebp
# 5d/pop-to-ebp
# c3/return
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# setup
(clear-stream _test-input-stream)
(clear-stream _test-input-buffered-file->buffer)
(clear-stream _test-output-stream)
(clear-stream _test-output-buffered-file->buffer)
#
(write _test-input-stream "fn foo {\n")
(write _test-input-stream "}\n")
(write _test-input-stream "fn bar {\n")
(write _test-input-stream "}\n")
# convert
(convert-mu _test-input-buffered-file _test-output-buffered-file)
(flush _test-output-buffered-file)
#? # dump _test-output-stream {{{
#? (write 2 "^")
#? (write-stream 2 _test-output-stream)
#? (write 2 "$\n")
#? (rewind-stream _test-output-stream)
#? # }}}
# check first function
(check-next-stream-line-equal _test-output-stream "foo:" "F - test-convert-multiple-function-skeletons/0")
(check-next-stream-line-equal _test-output-stream "# . prologue" "F - test-convert-multiple-function-skeletons/1")
(check-next-stream-line-equal _test-output-stream "55/push-ebp" "F - test-convert-multiple-function-skeletons/2")
(check-next-stream-line-equal _test-output-stream "89/<- %ebp 4/r32/esp" "F - test-convert-multiple-function-skeletons/3")
(check-next-stream-line-equal _test-output-stream "# . epilogue" "F - test-convert-multiple-function-skeletons/4")
(check-next-stream-line-equal _test-output-stream "89/<- %esp 5/r32/ebp" "F - test-convert-multiple-function-skeletons/5")
(check-next-stream-line-equal _test-output-stream "5d/pop-to-ebp" "F - test-convert-multiple-function-skeletons/6")
(check-next-stream-line-equal _test-output-stream "c3/return" "F - test-convert-multiple-function-skeletons/7")
# check second function
(check-next-stream-line-equal _test-output-stream "bar:" "F - test-convert-multiple-function-skeletons/10")
(check-next-stream-line-equal _test-output-stream "# . prologue" "F - test-convert-multiple-function-skeletons/11")
(check-next-stream-line-equal _test-output-stream "55/push-ebp" "F - test-convert-multiple-function-skeletons/12")
(check-next-stream-line-equal _test-output-stream "89/<- %ebp 4/r32/esp" "F - test-convert-multiple-function-skeletons/13")
(check-next-stream-line-equal _test-output-stream "# . epilogue" "F - test-convert-multiple-function-skeletons/14")
(check-next-stream-line-equal _test-output-stream "89/<- %esp 5/r32/ebp" "F - test-convert-multiple-function-skeletons/15")
(check-next-stream-line-equal _test-output-stream "5d/pop-to-ebp" "F - test-convert-multiple-function-skeletons/16")
(check-next-stream-line-equal _test-output-stream "c3/return" "F - test-convert-multiple-function-skeletons/17")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-convert-function-with-arg:
# function with one arg and a copy instruction
# fn foo n : int -> result/eax : int {
# result <- copy n
# }
# =>
# foo:
# # . prologue
# 55/push-ebp
# 89/<- %ebp 4/r32/esp
# {
# # result <- copy n
# 8b/-> *(ebp+8) 0/r32/eax
# }
# # . epilogue
# 89/<- %esp 5/r32/ebp
# 5d/pop-to-ebp
# c3/return
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# setup
(clear-stream _test-input-stream)
(clear-stream _test-input-buffered-file->buffer)
(clear-stream _test-output-stream)
(clear-stream _test-output-buffered-file->buffer)
#
(write _test-input-stream "fn foo {\n")
(write _test-input-stream "}\n")
# convert
(convert-mu _test-input-buffered-file _test-output-buffered-file)
(flush _test-output-buffered-file)
#? # dump _test-output-stream {{{
#? (write 2 "^")
#? (write-stream 2 _test-output-stream)
#? (write 2 "$\n")
#? (rewind-stream _test-output-stream)
#? # }}}
# check output
(check-next-stream-line-equal _test-output-stream "foo:" "F - test-convert-function-skeleton/0")
(check-next-stream-line-equal _test-output-stream "# . prologue" "F - test-convert-function-skeleton/1")
(check-next-stream-line-equal _test-output-stream "55/push-ebp" "F - test-convert-function-skeleton/2")
(check-next-stream-line-equal _test-output-stream "89/<- %ebp 4/r32/esp" "F - test-convert-function-skeleton/3")
(check-next-stream-line-equal _test-output-stream "# . epilogue" "F - test-convert-function-skeleton/4")
(check-next-stream-line-equal _test-output-stream "89/<- %esp 5/r32/ebp" "F - test-convert-function-skeleton/5")
(check-next-stream-line-equal _test-output-stream "5d/pop-to-ebp" "F - test-convert-function-skeleton/6")
(check-next-stream-line-equal _test-output-stream "c3/return" "F - test-convert-function-skeleton/7")
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
parse-mu: # in : (address buffered-file)
# pseudocode
# var curr-function = Program
# var line : (stream byte 512)
# var word-slice : slice
# while true # line loop
# clear-stream(line)
# read-line-buffered(in, line)
# if (line->write == 0) break # end of file
# while true # word loop
# word-slice = next-word-or-string(line)
# if slice-empty?(word-slice) # end of line
# break
# else if slice-starts-with?(word-slice, "#") # comment
# break # end of line
# else if slice-equal(word-slice, "fn")
# var new-function : (address function) = new function
# populate-mu-function(in, new-function)
# *curr-function = new-function
# curr-function = &new-function->next
# else
# abort()
#
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
52/push-edx
57/push-edi
# var line/ecx : (stream byte 512)
81 5/subop/subtract %esp 0x200/imm32
68/push 0x200/imm32/length
68/push 0/imm32/read
68/push 0/imm32/write
89/<- %ecx 4/r32/esp
# var word-slice/edx : slice
68/push 0/imm32/end
68/push 0/imm32/start
89/<- %edx 4/r32/esp
# var curr-function/edi : (address function) = Program
bf/copy-to-edi Program/imm32
{
$parse-mu:line-loop:
(clear-stream %ecx)
(read-line-buffered *(ebp+8) %ecx)
# if (line->write == 0) break
81 7/subop/compare *ecx 0/imm32
0f 84/jump-if-equal break/disp32
#? # dump line {{{
#? (write 2 "line: ^")
#? (write-stream 2 %ecx)
#? (write 2 "$\n")
#? (rewind-stream %ecx)
#? # }}}
{ # word loop
$parse-mu:word-loop:
(next-word-or-string %ecx %edx)
# if slice-empty?(word-slice) break
(slice-empty? %edx)
3d/compare-eax-and 0/imm32
0f 85/jump-if-not-equal break/disp32
# if (*word-slice->start == "#") break
# . eax = *word-slice->start
8b/-> *edx 0/r32/eax
8a/copy-byte *eax 0/r32/AL
81 4/subop/and %eax 0xff/imm32
# . if (eax == '#') break
3d/compare-eax-and 0x23/imm32/hash
0f 84/jump-if-equal break/disp32
# if (slice-equal?(word-slice, "fn")) parse a function
{
(slice-equal? %edx "fn")
3d/compare-eax-and 0/imm32
0f 84/jump-if-equal break/disp32
# var new-function/eax : (address function) = populate-mu-function()
(allocate Heap *Function-size) # => eax
(populate-mu-function-header %ecx %eax)
(populate-mu-function-body *(ebp+8) %eax)
# *curr-function = new-function
89/<- *edi 0/r32/eax
# curr-function = &new-function->next
8d/address-> *(eax+0x10) 7/r32/edi
e9/jump $parse-mu:word-loop/disp32
}
# otherwise abort
e9/jump $parse-mu:abort/disp32
} # end word loop
e9/jump loop/disp32
} # end line loop
$parse-mu:end:
# . reclaim locals
81 0/subop/add %esp 0x214/imm32
# . restore registers
5f/pop-to-edi
5a/pop-to-edx
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
$parse-mu:abort:
# error("unexpected top-level command: " word-slice "\n")
(write-buffered Stderr "unexpected top-level command: ")
(write-buffered Stderr %edx)
(write-buffered Stderr "\n")
(flush Stderr)
# . syscall(exit, 1)
bb/copy-to-ebx 1/imm32
b8/copy-to-eax 1/imm32/exit
cd/syscall 0x80/imm8
# never gets here
# errors considered:
# fn foo { {
# fn foo { }
# fn foo { } {
# fn foo # no block
populate-mu-function-header: # first-line : (address stream byte), out : (address function)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
57/push-edi
# edi = out
8b/-> *(ebp+0xc) 7/r32/edi
# var word-slice/ecx : slice
68/push 0/imm32/end
68/push 0/imm32/start
89/<- %ecx 4/r32/esp
# save function name
(next-word *(ebp+8) %ecx)
(slice-to-string Heap %ecx) # => eax
89/<- *edi 0/r32/eax
# assert that next token is '{'
(next-word *(ebp+8) %ecx)
(slice-equal? %ecx "{")
3d/compare-eax-and 0/imm32
74/jump-if-equal $populate-mu-function-header:abort/disp8
# assert that there's no further token
{
# word-slice = next-word(line)
(next-word *(ebp+8) %ecx)
# if (word-slice == '') break
(slice-empty? %ecx)
3d/compare-eax-and 0/imm32
75/jump-if-not-equal break/disp8
# if (slice-starts-with?(word-slice, "#")) break
# . eax = *word-slice->start
8b/-> *edx 0/r32/eax
8a/copy-byte *eax 0/r32/AL
81 4/subop/and %eax 0xff/imm32
# . if (eax == '#') break
3d/compare-eax-and 0x23/imm32/hash
74/jump-if-equal break/disp8
# otherwise abort
eb/jump $populate-mu-function-header:abort/disp8
}
$populate-mu-function-header:end:
# . reclaim locals
81 0/subop/add %esp 8/imm32
# . restore registers
5f/pop-to-edi
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
$populate-mu-function-header:abort:
# error("function header not in form 'fn <name> {'")
(write-buffered Stderr "function header not in form 'fn <name> {' -- '")
(rewind-stream *(ebp+8))
(write-stream 2 *(ebp+8))
(write-buffered Stderr "'\n")
(flush Stderr)
# . syscall(exit, 1)
bb/copy-to-ebx 1/imm32
b8/copy-to-eax 1/imm32/exit
cd/syscall 0x80/imm8
# never gets here
# errors considered:
# { abc
populate-mu-function-body: # in : (address buffered-file), out : (address function)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
52/push-edx
53/push-ebx
# var line/ecx : (stream byte 512)
81 5/subop/subtract %esp 0x200/imm32
68/push 0x200/imm32/length
68/push 0/imm32/read
68/push 0/imm32/write
89/<- %ecx 4/r32/esp
# var word-slice/edx : slice
68/push 0/imm32/end
68/push 0/imm32/start
89/<- %edx 4/r32/esp
# var open-curly-count/ebx : int = 1
bb/copy-to-ebx 1/imm32
{ # line loop
$populate-mu-function-body:line-loop:
# if (open-curly-count == 0) break
81 7/subop/compare %ebx 0/imm32
0f 84/jump-if-equal break/disp32
# line = read-line-buffered(in)
(clear-stream %ecx)
(read-line-buffered *(ebp+8) %ecx)
# if (line->write == 0) break
81 7/subop/compare *ecx 0/imm32
0f 84/jump-if-equal break/disp32
# word-slice = next-word(line)
(next-word %ecx %edx)
# if slice-empty?(word-slice) continue
(slice-empty? %ecx)
3d/compare-eax-and 0/imm32
75/jump-if-not-equal loop/disp8
# if (slice-starts-with?(word-slice, '#') continue
# . eax = *word-slice->start
8b/-> *edx 0/r32/eax
8a/copy-byte *eax 0/r32/AL
81 4/subop/and %eax 0xff/imm32
# . if (eax == '#') continue
3d/compare-eax-and 0x23/imm32/hash
74/jump-if-equal loop/disp8
{
# if slice-equal?(word-slice, "{") ++open-curly-count
{
(slice-equal? %ecx "{")
3d/compare-eax-and 0/imm32
74/jump-if-equal break/disp8
43/increment-ebx
eb/jump $curly-found:end/disp8
}
# else if slice-equal?(word-slice, "}") --open-curly-count
{
(slice-equal? %ecx "}")
3d/compare-eax-and 0/imm32
74/jump-if-equal break/disp8
4b/decrement-ebx
eb/jump $curly-found:end/disp8
}
# else break
eb/jump $populate-mu-function-body:end/disp8
}
# - check for invalid tokens after curly
$curly-found:end:
# second-word-slice = next-word(line)
(next-word %ecx %edx)
# if slice-empty?(second-word-slice) continue
(slice-empty? %ecx)
3d/compare-eax-and 0/imm32
0f 85/jump-if-not-equal loop/disp32
# if (slice-starts-with?(second-word-slice, '#') continue
# . eax = *second-word-slice->start
8b/-> *edx 0/r32/eax
8a/copy-byte *eax 0/r32/AL
81 4/subop/and %eax 0xff/imm32
# . if (eax == '#') continue
3d/compare-eax-and 0x23/imm32/hash
0f 84/jump-if-equal loop/disp32
# abort
eb/jump $populate-mu-function-body:abort/disp8
} # end line loop
$populate-mu-function-body:end:
# . reclaim locals
81 0/subop/add %esp 0x214/imm32
# . restore registers
5b/pop-to-ebx
5a/pop-to-edx
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
$populate-mu-function-body:abort:
# error("'{' or '}' should be on its own line, but got '")
(write-buffered Stderr "'{' or '}' should be on its own line, but got '")
(rewind-stream %ecx)
(write-stream 2 %ecx)
(write-buffered Stderr "'\n")
(flush Stderr)
# . syscall(exit, 1)
bb/copy-to-ebx 1/imm32
b8/copy-to-eax 1/imm32/exit
cd/syscall 0x80/imm8
# never gets here
check-mu-types:
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
#
$check-types:end:
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
emit-subx: # out : (address buffered-file)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
57/push-edi
# edi = out
8b/-> *(ebp+8) 7/r32/edi
# var curr/ecx : (address function) = Program
8b/-> *Program 1/r32/ecx
{
# if (curr == NULL) break
81 7/subop/compare %ecx 0/imm32
0f 84/jump-if-equal break/disp32
(emit-subx-function %edi %ecx)
# curr = curr->next
8b/-> *(ecx+0x10) 1/r32/ecx
e9/jump loop/disp32
}
$emit-subx:end:
# . restore registers
5f/pop-to-edi
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
# == Emitting a function
# Emit function header
# Emit function prologue
# Translate function body
# Emit function epilogue
emit-subx-function: # out : (address buffered-file), f : (address function)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
57/push-edi
# edi = out
8b/-> *(ebp+8) 7/r32/edi
# ecx = f
8b/-> *(ebp+0xc) 1/r32/ecx
#
(write-buffered %edi *ecx)
(write-buffered %edi ":\n")
(emit-subx-prologue %edi)
(emit-subx-block %edi *(ecx+4)) # TODO: offset
(emit-subx-epilogue %edi)
$emit-subx-function:end:
# . restore registers
5f/pop-to-edi
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
emit-subx-block: # out : (address buffered-file), block : (address block)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
#
$emit-subx-block:end:
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
emit-subx-statement: # out : (address buffered-file), stmt : (address statement), vars : (stack var), primitives : (address opcode-info), functions : (address function)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
# if stmt matches a primitive, emit it
{
(find-matching-function *(ebp+0x14) *(ebp+0xc))
3d/compare-eax-and 0/imm32
74/jump-if-equal break/disp8
(emit-subx-primitive *(ebp+8) *(ebp+0xc) *(ebp+0x10) %eax)
e9/jump $emit-subx-statement:end/disp32
}
# else if stmt matches a function, emit a call to it
{
(find-matching-function *(ebp+0x18) *(ebp+0xc))
3d/compare-eax-and 0/imm32
74/jump-if-equal break/disp8
(emit-subx-call *(ebp+8) *(ebp+0xc) *(ebp+0x10) %eax)
e9/jump $emit-subx-statement:end/disp32
}
# else abort
e9/jump $emit-subx-statement:abort/disp32
$emit-subx-statement:end:
# . restore registers
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
$emit-subx-statement:abort:
# error("couldn't translate '" stmt "'\n")
(write-buffered Stderr "couldn't translate '")
#? (emit-string Stderr *(ebp+0xc)) # TODO
(write-buffered Stderr "'\n")
(flush Stderr)
# . syscall(exit, 1)
bb/copy-to-ebx 1/imm32
b8/copy-to-eax 1/imm32/exit
cd/syscall 0x80/imm8
# never gets here
emit-subx-primitive: # out : (address buffered-file), stmt : (address statement), vars : (address variable), primitive : (address function)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
# - emit primitive name
8b/-> *(ebp+0x14) 1/r32/ecx
(write-buffered *(ebp+8) *(ecx+4)) # Function-subx-name
# - emit arguments
# var curr/ecx : (list var) = stmt->inouts
8b/-> *(ebp+0xc) 1/r32/ecx
8b/-> *(ecx+4) 1/r32/ecx # Stmt-inouts
{
# if (curr == null) break
81 7/subop/compare %ecx 0/imm32
74/jump-if-equal break/disp8
#
(emit-subx-call-operand *(ebp+8) *ecx)
# curr = curr->next
8b/-> *(ecx+4) 1/r32/ecx
}
$emit-subx-primitive:end:
# . restore registers
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
emit-subx-call: # out : (address buffered-file), stmt : (address statement), vars : (address variable), callee : (address function)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
51/push-ecx
#
(write-buffered *(ebp+8) "(")
# - emit function name
8b/-> *(ebp+0x14) 1/r32/ecx
(write-buffered *(ebp+8) *(ecx+4)) # Function-subx-name
# - emit arguments
# var curr/ecx : (list var) = stmt->inouts
8b/-> *(ebp+0xc) 1/r32/ecx
8b/-> *(ecx+4) 1/r32/ecx # Stmt-inouts
{
# if (curr == null) break
81 7/subop/compare %ecx 0/imm32
74/jump-if-equal break/disp8
#
(emit-subx-call-operand *(ebp+8) *ecx)
# curr = curr->next
8b/-> *(ecx+4) 1/r32/ecx
}
#
(write-buffered *(ebp+8) ")")
$emit-subx-call:end:
# . restore registers
59/pop-to-ecx
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
emit-subx-call-operand: # out : (address buffered-file), operand : (address variable)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
50/push-eax
#
(write-buffered *(ebp+8) Space)
(write-buffered *(ebp+8) "*(ebp+")
8b/-> *(ebp+0xc) 0/r32/eax
(print-int32-buffered *(ebp+8) *(eax+0xc)) # Var-stack-offset
(write-buffered *(ebp+8) ")")
$emit-subx-call-operand:end:
# . restore registers
58/pop-to-eax
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
find-matching-function: # functions : (address function), stmt : (address statement) -> result/eax : (address function)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
51/push-ecx
# var curr/ecx : (address function) = functions
8b/-> *(ebp+8) 1/r32/ecx
{
# if (curr == null) break
81 7/subop/compare %ecx 0/imm32
74/jump-if-equal break/disp8
# if match(curr, stmt) return curr
{
(mu-stmt-matches-function? *(ebp+0xc) %ecx) # => eax
3d/compare-eax-and 0/imm32
74/jump-if-equal break/disp8
89/<- %eax 1/r32/ecx
eb/jump $find-matching-function:end/disp8
}
# curr = curr->next
8b/-> *(ecx+0x10) 1/r32/ecx
eb/jump loop/disp8
}
# return null
b8/copy-to-eax 0/imm32
$find-matching-function:end:
# . restore registers
59/pop-to-ecx
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
mu-stmt-matches-function?: # stmt : (address statement), primitive : (address opcode-info) => result/eax : boolean
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# . save registers
51/push-ecx
# return primitive->name == stmt->operation
8b/-> *(ebp+8) 1/r32/ecx
8b/-> *(ebp+0xc) 0/r32/eax
(string-equal? *ecx *eax) # => eax
$mu-stmt-matches-function?:end:
# . restore registers
59/pop-to-ecx
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-emit-subx-statement-primitive:
# Primitive operation on a variable on the stack.
# increment foo
# =>
# ff 0/subop/increment *(ebp-8)
#
# There's a variable on the var stack as follows:
# name: 'foo'
# type: int
# location: -8 (negative numbers are on the stack;
# 0-7 are in registers;
# higher positive numbers are invalid)
#
# There's a primitive with this info:
# name: 'increment'
# inout: int/mem
# value: 'ff 0/subop/increment'
#
# There's nothing in functions.
#
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# setup
(clear-stream _test-output-stream)
(clear-stream _test-output-buffered-file->buffer)
# var-foo/ecx : var
68/push 0/imm32/no-register
68/push -8/imm32/stack-offset
68/push 1/imm32/block-depth
68/push 1/imm32/type-int
68/push "foo"/imm32
89/<- %ecx 4/r32/esp
# vars/edx : (stack 1)
51/push-ecx/var-foo
68/push 1/imm32/data-length
68/push 1/imm32/top
89/<- %edx 4/r32/esp
# operand/esi : (list var)
68/push 0/imm32/next
51/push-ecx/var-foo
89/<- %esi 4/r32/esp
# stmt/esi : statement
68/push 0/imm32/next
68/push 0/imm32/outputs
56/push-esi/operands
68/push "increment"/imm32/operation
89/<- %esi 4/r32/esp
# primitives/ebx : function
68/push 0/imm32/next
68/push 0/imm32/body
68/push 0/imm32/outputs
51/push-ecx/inouts # hack; in practice we won't have the same var in function definition and call
68/push "ff 0/subop/increment"/imm32/subx-name
68/push "increment"/imm32/name
89/<- %ebx 4/r32/esp
# convert
(emit-subx-statement _test-output-buffered-file %esi %edx %ebx 0)
(flush _test-output-buffered-file)
#? # dump _test-output-stream {{{
#? (write 2 "^")
#? (write-stream 2 _test-output-stream)
#? (write 2 "$\n")
#? (rewind-stream _test-output-stream)
#? # }}}
# check output
(check-next-stream-line-equal _test-output-stream "ff 0/subop/increment *(ebp+0xfffffff8)" "F - test-emit-subx-statement-primitive/0")
# . reclaim locals
81 0/subop/add %esp 0x48/imm32
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
test-emit-subx-statement-function-call:
# Call a function on a variable on the stack.
# f foo
# =>
# (f2 *(ebp-8))
# (Changing the function name supports overloading in general, but here it
# just serves to help disambiguate things.)
#
# There's a variable on the var stack as follows:
# name: 'foo'
# type: int
# location: -8 (negative numbers are on the stack;
# 0-7 are in registers;
# higher positive numbers are invalid)
#
# There's nothing in primitives.
#
# There's a function with this info:
# name: 'f'
# inout: int/mem
# value: 'f2'
#
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
# setup
(clear-stream _test-output-stream)
(clear-stream _test-output-buffered-file->buffer)
# var-foo/ecx : var
68/push 0/imm32/no-register
68/push -8/imm32/stack-offset
68/push 0/imm32/block-depth
68/push 1/imm32/type-int
68/push "foo"/imm32
89/<- %ecx 4/r32/esp
# vars/edx = (stack 1)
51/push-ecx/var-foo
68/push 1/imm32/data-length
68/push 1/imm32/top
89/<- %edx 4/r32/esp
# operands/esi : (list var)
68/push 0/imm32/next
51/push-ecx/var-foo
89/<- %esi 4/r32/esp
# stmt/esi : statement
68/push 0/imm32/next
68/push 0/imm32/outputs
56/push-esi/inouts
68/push "f"/imm32/operation
89/<- %esi 4/r32/esp
# functions/ebx : function
68/push 0/imm32/next
68/push 0/imm32/body
68/push 0/imm32/outputs
51/push-ecx/inouts # hack; in practice we won't have the same var in function definition and call
68/push "f2"/imm32/subx-name
68/push "f"/imm32/name
89/<- %ebx 4/r32/esp
# convert
(emit-subx-statement _test-output-buffered-file %esi %edx 0 %ebx)
(flush _test-output-buffered-file)
#? # dump _test-output-stream {{{
#? (write 2 "^")
#? (write-stream 2 _test-output-stream)
#? (write 2 "$\n")
#? (rewind-stream _test-output-stream)
#? # }}}
# check output
(check-next-stream-line-equal _test-output-stream "(f2 *(ebp+0xfffffff8))" "F - test-emit-subx-statement-function-call/0")
# . reclaim locals
81 0/subop/add %esp 0x3c/imm32
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
emit-subx-prologue: # out : (address buffered-file)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
#
(write-buffered *(ebp+8) "# . prologue\n")
(write-buffered *(ebp+8) "55/push-ebp\n")
(write-buffered *(ebp+8) "89/<- %ebp 4/r32/esp\n")
$emit-subx-prologue:end:
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
emit-subx-epilogue: # out : (address buffered-file)
# . prologue
55/push-ebp
89/<- %ebp 4/r32/esp
#
(write-buffered *(ebp+8) "# . epilogue\n")
(write-buffered *(ebp+8) "89/<- %esp 5/r32/ebp\n")
(write-buffered *(ebp+8) "5d/pop-to-ebp\n")
(write-buffered *(ebp+8) "c3/return\n")
$emit-subx-epilogue:end:
# . epilogue
89/<- %esp 5/r32/ebp
5d/pop-to-ebp
c3/return
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