mirror of
https://github.com/CPunch/LuaDecompy.git
synced 2024-11-22 14:50:05 +00:00
lparser.py: added support for while loops
This commit is contained in:
parent
78e137d033
commit
95ca3bb26b
52
README.md
52
README.md
@ -12,44 +12,46 @@ Lua has a relatively small instruction set (only 38 different opcodes!). This ma
|
||||
|
||||
```sh
|
||||
> cat example.lua && luac5.1 -o example.luac example.lua
|
||||
pp = "pri" .. "nt"
|
||||
i = 0
|
||||
|
||||
if 2 + 2 == 4 then
|
||||
_G[pp]("Hello world")
|
||||
while i < 10 do
|
||||
print(i)
|
||||
i = i + 1
|
||||
end
|
||||
|
||||
> python main.py example.luac
|
||||
example.luac
|
||||
|
||||
==== [[example.lua's constants]] ====
|
||||
|
||||
0: [STRING] pp
|
||||
1: [STRING] pri
|
||||
2: [STRING] nt
|
||||
3: [NUMBER] 4.0
|
||||
4: [STRING] _G
|
||||
5: [STRING] Hello world
|
||||
0: [STRING] i
|
||||
1: [NUMBER] 0.0
|
||||
2: [NUMBER] 10.0
|
||||
3: [STRING] print
|
||||
4: [NUMBER] 1.0
|
||||
|
||||
==== [[example.lua's dissassembly]] ====
|
||||
|
||||
[ 0] LOADK : R[0] K[1] ; load "pri" into R[0]
|
||||
[ 1] LOADK : R[1] K[2] ; load "nt" into R[1]
|
||||
[ 2] CONCAT : R[0] R[0] R[1] ; concat 2 values from R[0] to R[1], store into R[0]
|
||||
[ 3] SETGLOBAL : R[0] K[0] ;
|
||||
[ 4] EQ : R[0] K[3] K[3] ;
|
||||
[ 5] JMP : R[0] R[5] ;
|
||||
[ 6] GETGLOBAL : R[0] K[4] ;
|
||||
[ 7] GETGLOBAL : R[1] K[0] ;
|
||||
[ 8] GETTABLE : R[0] R[0] R[1] ;
|
||||
[ 9] LOADK : R[1] K[5] ; load "Hello world" into R[1]
|
||||
[ 10] CALL : R[0] R[2] R[1] ;
|
||||
[ 11] RETURN : R[0] R[1] R[0] ;
|
||||
[ 0] LOADK : R[0] K[1] ; load 0.0 into R[0]
|
||||
[ 1] SETGLOBAL : R[0] K[0] ;
|
||||
[ 2] GETGLOBAL : R[0] K[0] ;
|
||||
[ 3] LT : R[0] R[0] K[2] ;
|
||||
[ 4] JMP : R[0] 7 ;
|
||||
[ 5] GETGLOBAL : R[0] K[3] ;
|
||||
[ 6] GETGLOBAL : R[1] K[0] ;
|
||||
[ 7] CALL : R[0] 2 1 ;
|
||||
[ 8] GETGLOBAL : R[0] K[0] ;
|
||||
[ 9] ADD : R[0] R[0] K[4] ;
|
||||
[ 10] SETGLOBAL : R[0] K[0] ;
|
||||
[ 11] JMP : R[0] -10 ;
|
||||
[ 12] RETURN : R[0] 1 0 ;
|
||||
|
||||
==== [[example.lua's decompiled source]] ====
|
||||
|
||||
|
||||
pp = "pri" .. "nt"
|
||||
if 4.0 == 4.0 then
|
||||
_G[pp]("Hello world")
|
||||
i = 0.0
|
||||
while i < 10.0 do
|
||||
print(i)
|
||||
i = (i + 1.0)
|
||||
end
|
||||
|
||||
```
|
||||
46
lparser.py
46
lparser.py
@ -53,11 +53,17 @@ class LuaDecomp:
|
||||
self.__startStatement()
|
||||
self.__addExpr("local " + self.locals[indx] + " = " + expr)
|
||||
|
||||
def __getInstrAtPC(self, pc: int) -> Instruction:
|
||||
if pc < len(self.chunk.instructions):
|
||||
return self.chunk.instructions[pc]
|
||||
|
||||
raise Exception("Decompilation failed!")
|
||||
|
||||
def __getNextInstr(self) -> Instruction:
|
||||
if self.pc + 1 < len(self.chunk.instructions):
|
||||
return self.chunk.instructions[self.pc + 1]
|
||||
|
||||
return None
|
||||
raise Exception("Decompilation failed!")
|
||||
|
||||
def __getCurrInstr(self) -> Instruction:
|
||||
return self.chunk.instructions[self.pc]
|
||||
@ -102,6 +108,30 @@ class LuaDecomp:
|
||||
def __emitOperand(self, a: int, b: str, c: str, op: str) -> None:
|
||||
self.__setReg(a, "(" + b + op + c + ")")
|
||||
|
||||
def __compJmp(self, op: str):
|
||||
instr = self.__getCurrInstr()
|
||||
jmpType = "if"
|
||||
scopeStart = "then"
|
||||
|
||||
# we need to check if the jmp location has a jump back (if so, it's a while loop)
|
||||
jmp = self.__getNextInstr().B + 1
|
||||
jmpToInstr = self.__getInstrAtPC(self.pc + jmp)
|
||||
|
||||
if jmpToInstr.opcode == Opcodes.JMP:
|
||||
# if this jump jumps back to this compJmp, it's a loop!
|
||||
if self.pc + jmp + jmpToInstr.B <= self.pc + 1:
|
||||
jmpType = "while"
|
||||
scopeStart = "do"
|
||||
|
||||
self.__startStatement()
|
||||
if instr.A > 0:
|
||||
self.__addExpr("%s not " % jmpType)
|
||||
else:
|
||||
self.__addExpr("%s " % jmpType)
|
||||
self.__addExpr(self.__readRK(instr.B) + op + self.__readRK(instr.C) + " ")
|
||||
self.__startScope("%s " % scopeStart, jmp)
|
||||
self.pc += 1 # skip next instr
|
||||
|
||||
# 'RK's are special in because can be a register or a konstant. a bitflag is read to determine which
|
||||
def __readRK(self, rk: int) -> str:
|
||||
if (whichRK(rk)) > 0:
|
||||
@ -163,19 +193,11 @@ class LuaDecomp:
|
||||
elif instr.opcode == Opcodes.JMP:
|
||||
pass
|
||||
elif instr.opcode == Opcodes.EQ:
|
||||
self.__startStatement()
|
||||
if instr.A > 0:
|
||||
self.__addExpr("if not ")
|
||||
else:
|
||||
self.__addExpr("if ")
|
||||
self.__addExpr(self.__readRK(instr.B) + " == " + self.__readRK(instr.C) + " ")
|
||||
self.__startScope("then ", self.__getNextInstr().B + 1)
|
||||
|
||||
self.pc += 1 # skip next instr
|
||||
self.__compJmp(" == ")
|
||||
elif instr.opcode == Opcodes.LT:
|
||||
self.__emitOperand(instr.A, self.__readRK(instr.B), self.__readRK(instr.C), " < ")
|
||||
self.__compJmp(" < ")
|
||||
elif instr.opcode == Opcodes.LE:
|
||||
self.__emitOperand(instr.A, instr.B, instr.C, " <= ")
|
||||
self.__compJmp(" <= ")
|
||||
elif instr.opcode == Opcodes.CALL:
|
||||
preStr = ""
|
||||
callStr = ""
|
||||
|
||||
@ -101,8 +101,8 @@ class Instruction:
|
||||
if self.type == InstructionType.ABC:
|
||||
# by default, treat them as registers
|
||||
A = "R[%d]" % self.A
|
||||
B = "R[%d]" % self.B
|
||||
C = "R[%d]" % self.C
|
||||
B = "%d" % self.B
|
||||
C = "%d" % self.C
|
||||
|
||||
# these opcodes have RKs for B & C
|
||||
if self.opcode in _RKBCInstr:
|
||||
@ -114,7 +114,7 @@ class Instruction:
|
||||
regs = "%6s %6s %6s" % (A, B, C)
|
||||
elif self.type == InstructionType.ABx or self.type == InstructionType.AsBx:
|
||||
A = "R[%d]" % self.A
|
||||
B = "R[%d]" % self.B
|
||||
B = "%d" % self.B
|
||||
|
||||
if self.opcode in _KBx:
|
||||
B = "K[%d]" % self.B
|
||||
|
||||
Loading…
Reference in New Issue
Block a user