From 9da0d0ffbdaf9612319b2f074d61ef99cff2ef08 Mon Sep 17 00:00:00 2001 From: CPunch Date: Sun, 14 Aug 2022 01:36:05 -0500 Subject: [PATCH] lp: support FORPREP && FORLOOP --- README.md | 58 +++++++++++++++++++++++++++++------------------------- lparser.py | 23 +++++++++++++++++++--- lundump.py | 2 +- 3 files changed, 52 insertions(+), 31 deletions(-) diff --git a/README.md b/README.md index 432abf6..d461be5 100644 --- a/README.md +++ b/README.md @@ -12,47 +12,51 @@ 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 = 10, 2 +local total = 0 -repeat - print(i + x) - i = i - 1 -until i < 0 +for i = 0, 9, 1 do + total = total + i + print(total) +end > python main.py example.luac example.luac ==== [[example.lua's constants]] ==== -0: [NUMBER] 10.0 -1: [NUMBER] 2.0 -2: [STRING] print -3: [NUMBER] 1.0 -4: [NUMBER] 0.0 +0: [NUMBER] 0.0 +1: [NUMBER] 9.0 +2: [NUMBER] 1.0 +3: [STRING] print ==== [[example.lua's locals]] ==== -R[0]: i -R[1]: x +R[0]: total +R[1]: (for index) +R[2]: (for limit) +R[3]: (for step) +R[4]: i ==== [[example.lua's dissassembly]] ==== -[ 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] ; 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 : 0 1 0 ; +[ 0] LOADK : R[0] K[0] ; load 0.0 into R[0] +[ 1] LOADK : R[1] K[0] ; load 0.0 into R[1] +[ 2] LOADK : R[2] K[1] ; load 9.0 into R[2] +[ 3] LOADK : R[3] K[2] ; load 1.0 into R[3] +[ 4] FORPREP : R[1] 4 ; +[ 5] ADD : R[0] R[0] R[4] ; add R[4] to R[0], place into R[0] +[ 6] GETGLOBAL : R[5] K[3] ; move _G["print"] into R[5] +[ 7] MOVE : 6 0 0 ; move R[0] into R[6] +[ 8] CALL : 5 2 1 ; +[ 9] FORLOOP : R[1] -5 ; +[ 10] RETURN : 0 1 0 ; ==== [[example.lua's decompiled source]] ==== -local i = 10.0 -local x = 2.0 -repeat - print((i + x)) - i = (i - 1.0) -until i < 0.0 +local total = 0.0 +for i = 0.0, 9.0, 1.0 do + total = (total + i) + print(total) +end + ``` \ No newline at end of file diff --git a/lparser.py b/lparser.py index b85e84d..b4ecb4d 100644 --- a/lparser.py +++ b/lparser.py @@ -29,6 +29,13 @@ class _Line: self.src = src self.scope = scope +def isValidLocal(ident: str) -> bool: + for c in ident: + if c not in "abcdefghijklmnopqrstuvwxyz1234567890_": + return False + + return True + class LuaDecomp: def __init__(self, chunk: Chunk): self.chunk = chunk @@ -124,11 +131,16 @@ class LuaDecomp: def __loadLocals(self): for i in range(len(self.chunk.locals)): - if not self.chunk.locals[i].name == "": - self.locals[i] = self.chunk.locals[i].name - else: + name = self.chunk.locals[i].name + if isValidLocal(name): + self.locals[i] = name + elif "(for " not in name: # if it's a for loop register, ignore self.__makeLocalIdentifier(i) + # when you *know* the register *has* to be a local (for loops, etc.) + def __getLocal(self, indx: int) -> str: + return self.locals[indx] if indx in self.locals else self.__makeLocalIdentifier(indx) + def __getReg(self, indx: int) -> str: self.__addUseTraceback(indx) @@ -336,5 +348,10 @@ class LuaDecomp: elif instr.opcode == Opcodes.RETURN: self.__endStatement() pass # no-op for now + elif instr.opcode == Opcodes.FORLOOP: + pass # no-op for now + elif instr.opcode == Opcodes.FORPREP: + self.__addExpr("for %s = %s, %s, %s " % (self.__getLocal(instr.A+3), self.__getReg(instr.A), self.__getReg(instr.A + 1), self.__getReg(instr.A + 2))) + self.__startScope("do", self.pc, instr.B) else: raise Exception("unsupported instruction: %s" % instr.toString()) \ No newline at end of file diff --git a/lundump.py b/lundump.py index 7fef536..15b8c28 100644 --- a/lundump.py +++ b/lundump.py @@ -400,7 +400,7 @@ class LuaUndump: # locals num = self.get_int() for i in range(num): - name = self.get_string(None) # local name + name = self.get_string(None)[:-1] # local name ([:-1] to remove the NULL terminator) start = self.get_int() # local start PC end = self.get_int() # local end PC chunk.appendLocal(Local(name, start, end))