📝 doc: roadmap
_
parent
bebc96916b
commit
5c4a545369
|
|
@ -0,0 +1,14 @@
|
|||
LunarWaveVM is a Lua 5.4 virtual machine written in Rust.
|
||||
|
||||
|
||||
|
||||
# Roadmap
|
||||
|
||||
- [x] Loading simple pre-compiled bytecode programs
|
||||
- [x] Hash tables
|
||||
- [x] Fizzbuzz
|
||||
- [ ] Closures
|
||||
- [ ] Garbage collection
|
||||
- [ ] Long strings
|
||||
- [ ] Using arrays internally for tables
|
||||
- [ ] Compiling Lua source code to bytecode
|
||||
176
notes.md
176
notes.md
|
|
@ -1,176 +0,0 @@
|
|||
Lua source code
|
||||
|
||||
`hello.lua`
|
||||
|
||||
```lua
|
||||
print "Hello."
|
||||
```
|
||||
|
||||
`math.lua`
|
||||
|
||||
```lua
|
||||
local function add (a, b)
|
||||
return a + b
|
||||
end
|
||||
|
||||
print (("1 + 2 = %i"):format (add (1, 2)))
|
||||
```
|
||||
|
||||
luac5.4 listing
|
||||
|
||||
```
|
||||
main <hello.lua:0,0> (5 instructions at 0x564f4fd74cc0)
|
||||
0+ params, 2 slots, 1 upvalue, 0 locals, 2 constants, 0 functions
|
||||
1 [1] VARARGPREP 0
|
||||
2 [1] GETTABUP 0 0 0 ; _ENV "print"
|
||||
3 [1] LOADK 1 1 ; "Hello."
|
||||
4 [1] CALL 0 2 1 ; 1 in 0 out
|
||||
5 [1] RETURN 0 1 1 ; 0 out
|
||||
```
|
||||
|
||||
```
|
||||
main <math.lua:0,0> (12 instructions at 0x55ee2417acc0)
|
||||
0+ params, 7 slots, 1 upvalue, 1 local, 3 constants, 1 function
|
||||
1 [1] VARARGPREP 0
|
||||
2 [3] CLOSURE 0 0 ; 0x55ee2417b000
|
||||
3 [5] GETTABUP 1 0 0 ; _ENV "print"
|
||||
4 [5] LOADK 2 1 ; "1 + 2 = %i"
|
||||
5 [5] SELF 2 2 2k ; "format"
|
||||
6 [5] MOVE 4 0
|
||||
7 [5] LOADI 5 1
|
||||
8 [5] LOADI 6 2
|
||||
9 [5] CALL 4 3 0 ; 2 in all out
|
||||
10 [5] CALL 2 0 0 ; all in all out
|
||||
11 [5] CALL 1 0 1 ; all in 0 out
|
||||
12 [5] RETURN 1 1 1 ; 0 out
|
||||
|
||||
function <math.lua:1,3> (4 instructions at 0x55ee2417b000)
|
||||
2 params, 3 slots, 0 upvalues, 2 locals, 0 constants, 0 functions
|
||||
1 [2] ADD 2 0 1
|
||||
2 [2] MMBIN 0 1 6 ; __add
|
||||
3 [2] RETURN1 2
|
||||
4 [3] RETURN0
|
||||
```
|
||||
|
||||
```
|
||||
main <test_vectors/is_93.lua:0,0> (14 instructions at 0x559f55e1ecd0)
|
||||
0+ params, 2 slots, 1 upvalue, 1 local, 5 constants, 1 function
|
||||
1 [1] VARARGPREP 0
|
||||
2 [1] GETTABUP 0 0 0 ; _ENV "arg"
|
||||
3 [1] GETI 0 0 1
|
||||
4 [1] EQK 0 1 0 ; "93"
|
||||
5 [1] JMP 4 ; to 10
|
||||
6 [2] GETTABUP 0 0 2 ; _ENV "print"
|
||||
7 [2] LOADK 1 3 ; "it's 93"
|
||||
8 [2] CALL 0 2 1 ; 1 in 0 out
|
||||
9 [2] JMP 3 ; to 13
|
||||
10 [4] GETTABUP 0 0 2 ; _ENV "print"
|
||||
11 [4] LOADK 1 4 ; "it's not 93"
|
||||
12 [4] CALL 0 2 1 ; 1 in 0 out
|
||||
13 [9] CLOSURE 0 0 ; 0x559f55e1f3d0
|
||||
14 [9] RETURN 1 1 1 ; 0 out
|
||||
constants (5) for 0x559f55e1ecd0:
|
||||
0 S "arg"
|
||||
1 S "93"
|
||||
2 S "print"
|
||||
3 S "it's 93"
|
||||
4 S "it's not 93"
|
||||
locals (1) for 0x559f55e1ecd0:
|
||||
0 unused_fn 14 15
|
||||
upvalues (1) for 0x559f55e1ecd0:
|
||||
0 _ENV 1 0
|
||||
|
||||
function <test_vectors/is_93.lua:7,9> (4 instructions at 0x559f55e1f3d0)
|
||||
0 params, 2 slots, 1 upvalue, 0 locals, 2 constants, 0 functions
|
||||
1 [8] GETTABUP 0 0 0 ; _ENV "print"
|
||||
2 [8] LOADK 1 1 ; "unused"
|
||||
3 [8] CALL 0 2 1 ; 1 in 0 out
|
||||
4 [9] RETURN0
|
||||
constants (2) for 0x559f55e1f3d0:
|
||||
0 S "print"
|
||||
1 S "unused"
|
||||
locals (0) for 0x559f55e1f3d0:
|
||||
upvalues (1) for 0x559f55e1f3d0:
|
||||
0 _ENV 0 0
|
||||
```
|
||||
|
||||
Octal dump of luac5.4 byte code
|
||||
|
||||
```
|
||||
0000000 1b 4c 75 61 54 00 19 93 0d 0a 1a 0a 04 08 08 78 >.LuaT..........x<
|
||||
0000020 56 00 00 00 00 00 00 00 00 00 00 00 28 77 40 01 >V...........(w@.<
|
||||
0000040 8b 40 68 65 6c 6c 6f 2e 6c 75 61 80 80 00 01 02 >.@hello.lua.....<
|
||||
0000060 85 51 00 00 00 0b 00 00 00 83 80 00 00 44 00 02 >.Q...........D..<
|
||||
0000100 01 46 00 01 01 82 04 86 70 72 69 6e 74 04 87 48 >.F......print..H<
|
||||
0000120 65 6c 6c 6f 2e 81 01 00 00 80 85 01 00 00 00 00 >ello............<
|
||||
0000140 80 80 81 85 5f 45 4e 56 >...._ENV<
|
||||
0000150
|
||||
```
|
||||
|
||||
```
|
||||
0000000 1b 4c 75 61 54 00 19 93 0d 0a 1a 0a 04 08 08 78 >.LuaT..........x<
|
||||
0000020 56 00 00 00 00 00 00 00 00 00 00 00 28 77 40 01 >V...........(w@.<
|
||||
0000040 8a 40 6d 61 74 68 2e 6c 75 61 80 80 00 01 07 8c >.@math.lua......<
|
||||
0000060 51 00 00 00 4f 00 00 00 8b 00 00 00 03 81 00 00 >Q...O...........<
|
||||
0000100 14 81 02 02 00 02 00 00 81 02 00 80 01 83 00 80 >................<
|
||||
0000120 44 02 03 00 44 01 00 00 c4 00 00 01 c6 00 01 01 >D...D...........<
|
||||
0000140 83 04 86 70 72 69 6e 74 04 8b 31 20 2b 20 32 20 >...print..1 + 2 <
|
||||
0000160 3d 20 25 69 04 87 66 6f 72 6d 61 74 81 01 00 00 >= %i..format....<
|
||||
0000200 81 80 81 83 02 00 03 84 22 01 00 01 2e 00 01 06 >........".......<
|
||||
0000220 48 01 02 00 47 01 01 00 80 80 80 84 01 00 00 01 >H...G...........<
|
||||
0000240 80 82 82 61 80 84 82 62 80 84 80 8c 01 02 02 00 >...a...b........<
|
||||
0000260 00 00 00 00 00 00 00 00 80 81 84 61 64 64 82 8c >...........add..<
|
||||
0000300 81 85 5f 45 4e 56 >.._ENV<
|
||||
0000306
|
||||
|
||||
```
|
||||
|
||||
# Interpretation of byte code
|
||||
|
||||
Overall structure
|
||||
|
||||
- Roughly 32 byte header with magic number, version number, etc.
|
||||
- File name
|
||||
- `80 80 00 01 02 85` header for main function
|
||||
- Packed 4-byte instructions for main function
|
||||
- `82` or `83` length prefix for string table
|
||||
- String table for main function
|
||||
- `81 01 00 00 81 80 81 83 02 00 03 84` header for "add" function
|
||||
- Packed 4-byte instructions for "add" function
|
||||
- `80 80 80 84 01 00 00 01 80` Header for file-scope debug symbols?
|
||||
- File-scope debug symbols?
|
||||
- String table for entire file?
|
||||
|
||||
## Bytecodes
|
||||
|
||||
Per lopcodes.h, instructions are 32 bits long, always.
|
||||
The opcode is encoded in the first (highest?) 7 bits.
|
||||
|
||||
```
|
||||
83 80 00 00 ; 0x03 = 3 = LOADK
|
||||
0b 00 00 00 ; 0x0b = 11 = GETTABUP
|
||||
22 01 00 01 ; 0x22 = 34 = ADD
|
||||
2e 00 01 06 ; 0x2e = 46 = MMBIN
|
||||
c4 00 00 01 ; 0xc4 = 68 = CALL
|
||||
44 00 02 01 ; 0x44 = 68 = CALL
|
||||
46 00 01 01 ; 0x46 = 70 = RETURN
|
||||
47 01 01 00 ; 0x47 = 71 = RETURN0
|
||||
48 01 02 00 ; 0x48 = 72 = RETURN1
|
||||
51 00 00 00 ; 0x51 = 81 = VARARGPREP
|
||||
```
|
||||
|
||||
## Strings
|
||||
|
||||
Filenames are encoded at the top, and there's a string table at the bottom.
|
||||
|
||||
Strings appear to be prefixed with a variable-length length prefix.
|
||||
There is an extra byte before each string which I can't account for,
|
||||
and the lengths seem to be off by one, e.g. 0x84 is a length of 3, not 4.
|
||||
|
||||
| --- |
|
||||
| "add" | 81 84 61 64 64
|
||||
| "_ENV" | 81 85 5f 45 4e 56
|
||||
| "print" | 04 86 70 72 69 6e 74
|
||||
| "format" | 04 87 66 6f 72 6d 61 74
|
||||
| "@math.lua" | 01 8a 40 6d 61 74 68 2e 6c 75 61
|
||||
| "1 + 2 = %i" | 04 8b 31 20 2b 20 32 20 3d 20 25 69
|
||||
Binary file not shown.
|
After Width: | Height: | Size: 28 KiB |
|
|
@ -1,10 +1,10 @@
|
|||
for i = 1, 50 do
|
||||
if i % 3 == 0 and i % 5 == 0 then
|
||||
print ("FizzBuzz")
|
||||
print (i, "FizzBuzz")
|
||||
elseif i % 3 == 0 then
|
||||
print ("Fizz")
|
||||
print (i, "Fizz")
|
||||
elseif i % 5 == 0 then
|
||||
print ("Buzz")
|
||||
print (i, "Buzz")
|
||||
else
|
||||
print (i)
|
||||
end
|
||||
|
|
|
|||
Loading…
Reference in New Issue