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lundump.py: better instruction annotations

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This commit is contained in:
CPunch 2022-08-12 17:31:15 -05:00
parent 0d947f4f3d
commit 5d91dbbc64
2 changed files with 27 additions and 16 deletions
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29
README.md
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@ -12,23 +12,22 @@ Lua has a relatively small instruction set (only 38 different opcodes!). This ma
```sh
> cat example.lua && luac5.1 -o example.luac example.lua
local i, x = 0, 2
local i, x = 10, 2
repeat
print(i + x)
i = i + 1
until i < 10
i = i - 1
until i < 0
> python main.py example.luac
example.luac
==== [[example.lua's constants]] ====
0: [NUMBER] 0.0
0: [NUMBER] 10.0
1: [NUMBER] 2.0
2: [STRING] print
3: [NUMBER] 1.0
4: [NUMBER] 10.0
4: [NUMBER] 0.0
==== [[example.lua's locals]] ====
@ -37,23 +36,23 @@ R[1]: x
==== [[example.lua's dissassembly]] ====
[ 0] LOADK : R[0] K[0] ; load 0.0 into R[0]
[ 0] LOADK : R[0] K[0] ; load 10.0 into R[0]
[ 1] LOADK : R[1] K[1] ; load 2.0 into R[1]
[ 2] GETGLOBAL : R[2] K[2] ;
[ 3] ADD : R[3] R[0] R[1] ;
[ 4] CALL : R[2] 2 1 ;
[ 5] ADD : R[0] R[0] K[3] ;
[ 2] GETGLOBAL : R[2] K[2] ; move _G["print"] into R[2]
[ 3] ADD : R[3] R[0] R[1] ; add R[1] to R[0], place into R[3]
[ 4] CALL : 2 2 1 ;
[ 5] SUB : R[0] R[0] K[3] ; sub K[3] from R[0], place into R[0]
[ 6] LT : R[0] R[0] K[4] ;
[ 7] JMP : R[0] -6 ;
[ 8] RETURN : R[0] 1 0 ;
[ 8] RETURN : 0 1 0 ;
==== [[example.lua's decompiled source]] ====
local i = 0.0
local i = 10.0
local x = 2.0
repeat
print((i + x))
i = (i + 1.0)
until i < 10.0
i = (i - 1.0)
until i < 0.0
```

14
lundump.py
View File

@ -100,15 +100,17 @@ class Instruction:
if self.type == InstructionType.ABC:
# by default, treat them as registers
A = "R[%d]" % self.A
A = "%d" % self.A
B = "%d" % self.B
C = "%d" % self.C
# these opcodes have RKs for B & C
if self.opcode in _RKBCInstr:
A = "R[%d]" % self.A
B = self.__formatRK(self.B)
C = self.__formatRK(self.C)
elif self.opcode in _RKCInstr: # just for C
A = "R[%d]" % self.A
C = self.__formatRK(self.C)
regs = "%6s %6s %6s" % (A, B, C)
@ -128,6 +130,16 @@ class Instruction:
return "move R[%d] into R[%d]" % (self.B, self.A)
elif self.opcode == Opcodes.LOADK:
return "load %s into R[%d]" % (chunk.getConstant(self.B).toCode(), self.A)
elif self.opcode == Opcodes.GETGLOBAL:
return 'move _G[%s] into R[%d]' % (chunk.getConstant(self.B).toCode(), self.A)
elif self.opcode == Opcodes.ADD:
return 'add %s to %s, place into R[%d]' % (self.__formatRK(self.C), self.__formatRK(self.B), self.A)
elif self.opcode == Opcodes.SUB:
return 'sub %s from %s, place into R[%d]' % (self.__formatRK(self.C), self.__formatRK(self.B), self.A)
elif self.opcode == Opcodes.MUL:
return 'mul %s to %s, place into R[%d]' % (self.__formatRK(self.C), self.__formatRK(self.B), self.A)
elif self.opcode == Opcodes.DIV:
return 'div %s from %s, place into R[%d]' % (self.__formatRK(self.C), self.__formatRK(self.B), self.A)
elif self.opcode == Opcodes.CONCAT:
count = self.C - self.B + 1
return "concat %d values from R[%d] to R[%d], store into R[%d]" % (count, self.B, self.C, self.A)