StripSymbols.cpp revision dec628eead87b20773c98a00830580df211acc98
1e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner//===- StripSymbols.cpp - Strip symbols and debug info from a module ------===// 2fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 3e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// The LLVM Compiler Infrastructure 4e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// 5e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// This file was developed by the LLVM research group and is distributed under 6e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// the University of Illinois Open Source License. See LICENSE.TXT for details. 7fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// 8e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner//===----------------------------------------------------------------------===// 9e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// 10e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// This file implements stripping symbols out of symbol tables. 11e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// 12e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// Specifically, this allows you to strip all of the symbols out of: 13e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// * All functions in a module 14e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// * All non-essential symbols in a module (all function symbols + all module 15e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// scope symbols) 16e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// * Debug information. 17e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// 18e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// Notice that: 19e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// * This pass makes code much less readable, so it should only be used in 20fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman// situations where the 'strip' utility would be used (such as reducing 21e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// code size, and making it harder to reverse engineer code). 22e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner// 23e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner//===----------------------------------------------------------------------===// 24e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner 25e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner#include "llvm/Transforms/IPO.h" 26dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner#include "llvm/Constants.h" 27dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner#include "llvm/DerivedTypes.h" 28dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner#include "llvm/Instructions.h" 29e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner#include "llvm/Module.h" 30e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner#include "llvm/Pass.h" 31ef9b9a793949469cdaa4ab6d0173136229dcab7bReid Spencer#include "llvm/ValueSymbolTable.h" 3278d033e086e19e016273de014f9214aa6f3f844bReid Spencer#include "llvm/TypeSymbolTable.h" 339133fe28954d498fc4de13064c7d65bd811de02cReid Spencer#include "llvm/Support/Compiler.h" 34e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattnerusing namespace llvm; 35e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner 36e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattnernamespace { 379133fe28954d498fc4de13064c7d65bd811de02cReid Spencer class VISIBILITY_HIDDEN StripSymbols : public ModulePass { 38e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner bool OnlyDebugInfo; 39e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner public: 40e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner StripSymbols(bool ODI = false) : OnlyDebugInfo(ODI) {} 41e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner 42e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner virtual bool runOnModule(Module &M); 43e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner 44e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner virtual void getAnalysisUsage(AnalysisUsage &AU) const { 45e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner AU.setPreservesAll(); 46e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner } 47e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner }; 487f8897f22e88271cfa114998a4d6088e7c8e8e11Chris Lattner RegisterPass<StripSymbols> X("strip", "Strip all symbols from a module"); 49e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner} 50e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner 51e3ad43c828280cf11e8631f1a814a51a0b168016Chris LattnerModulePass *llvm::createStripSymbolsPass(bool OnlyDebugInfo) { 52e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner return new StripSymbols(OnlyDebugInfo); 53e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner} 54e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner 55dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattnerstatic void RemoveDeadConstant(Constant *C) { 56dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner assert(C->use_empty() && "Constant is not dead!"); 57dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner std::vector<Constant*> Operands; 58dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i) 59dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner if (isa<DerivedType>(C->getOperand(i)->getType()) && 60dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner C->getOperand(i)->hasOneUse()) 61dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner Operands.push_back(C->getOperand(i)); 62dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) { 63dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner if (!GV->hasInternalLinkage()) return; // Don't delete non static globals. 64dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner GV->eraseFromParent(); 65dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner } 66dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner else if (!isa<Function>(C)) 67dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner C->destroyConstant(); 68fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman 69dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner // If the constant referenced anything, see if we can delete it as well. 70dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner while (!Operands.empty()) { 71dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner RemoveDeadConstant(Operands.back()); 72dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner Operands.pop_back(); 73dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner } 74dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner} 75e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner 767f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner// Strip the symbol table of its names. 777f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner// 787f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattnerstatic void StripSymtab(ValueSymbolTable &ST) { 797f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner for (ValueSymbolTable::iterator VI = ST.begin(), VE = ST.end(); VI != VE; ) { 80dec628eead87b20773c98a00830580df211acc98Chris Lattner Value *V = VI->getValue(); 817f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner ++VI; 827f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner if (!isa<GlobalValue>(V) || cast<GlobalValue>(V)->hasInternalLinkage()) { 837f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner // Set name to "", removing from symbol table! 847f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner V->setName(""); 857f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner } 867f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner } 877f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner} 887f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner 897f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner// Strip the symbol table of its names. 907f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattnerstatic void StripTypeSymtab(TypeSymbolTable &ST) { 917f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner for (TypeSymbolTable::iterator TI = ST.begin(), E = ST.end(); TI != E; ) 927f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner ST.remove(TI++); 937f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner} 947f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner 957f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner 967f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner 97e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattnerbool StripSymbols::runOnModule(Module &M) { 98e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner // If we're not just stripping debug info, strip all symbols from the 99e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner // functions and the names from any internal globals. 100e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner if (!OnlyDebugInfo) { 1017f8897f22e88271cfa114998a4d6088e7c8e8e11Chris Lattner for (Module::global_iterator I = M.global_begin(), E = M.global_end(); 1027f8897f22e88271cfa114998a4d6088e7c8e8e11Chris Lattner I != E; ++I) 103e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner if (I->hasInternalLinkage()) 104e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner I->setName(""); // Internal symbols can't participate in linkage 105e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner 106e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) { 107e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner if (I->hasInternalLinkage()) 108e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner I->setName(""); // Internal symbols can't participate in linkage 1097f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner StripSymtab(I->getValueSymbolTable()); 110e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner } 111b2f6c0075cc1aafce3c83a756242f148429ade0fChris Lattner 112b2f6c0075cc1aafce3c83a756242f148429ade0fChris Lattner // Remove all names from types. 1137f1444bc0aefdd924e9b231e20d4c0529311e141Chris Lattner StripTypeSymtab(M.getTypeSymbolTable()); 114e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner } 115e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner 116dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner // Strip debug info in the module if it exists. To do this, we remove 117dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner // llvm.dbg.func.start, llvm.dbg.stoppoint, and llvm.dbg.region.end calls, and 118dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner // any globals they point to if now dead. 119688b0490e22eb67623f5aaa24406209be74efcb2Reid Spencer Function *FuncStart = M.getFunction("llvm.dbg.func.start"); 120688b0490e22eb67623f5aaa24406209be74efcb2Reid Spencer Function *StopPoint = M.getFunction("llvm.dbg.stoppoint"); 121688b0490e22eb67623f5aaa24406209be74efcb2Reid Spencer Function *RegionStart = M.getFunction("llvm.dbg.region.start"); 122688b0490e22eb67623f5aaa24406209be74efcb2Reid Spencer Function *RegionEnd = M.getFunction("llvm.dbg.region.end"); 123688b0490e22eb67623f5aaa24406209be74efcb2Reid Spencer Function *Declare = M.getFunction("llvm.dbg.declare"); 1244ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey if (!FuncStart && !StopPoint && !RegionStart && !RegionEnd && !Declare) 125dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner return true; 126dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner 127dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner std::vector<GlobalVariable*> DeadGlobals; 128dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner 129dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner // Remove all of the calls to the debugger intrinsics, and remove them from 130dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner // the module. 131dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner if (FuncStart) { 132dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner while (!FuncStart->use_empty()) { 133dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner CallInst *CI = cast<CallInst>(FuncStart->use_back()); 134dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner Value *Arg = CI->getOperand(1); 1354ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey assert(CI->use_empty() && "llvm.dbg intrinsic should have void result"); 136dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner CI->eraseFromParent(); 137dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner if (Arg->use_empty()) 138dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Arg)) 139dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner DeadGlobals.push_back(GV); 140dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner } 141dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner FuncStart->eraseFromParent(); 142dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner } 143dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner if (StopPoint) { 144dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner while (!StopPoint->use_empty()) { 145dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner CallInst *CI = cast<CallInst>(StopPoint->use_back()); 146f4321a3a438833dade457e24da6e1e6907cabcd5Jim Laskey Value *Arg = CI->getOperand(3); 1474ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey assert(CI->use_empty() && "llvm.dbg intrinsic should have void result"); 148dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner CI->eraseFromParent(); 149dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner if (Arg->use_empty()) 150dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Arg)) 151dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner DeadGlobals.push_back(GV); 152dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner } 153dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner StopPoint->eraseFromParent(); 154dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner } 1554ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey if (RegionStart) { 1564ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey while (!RegionStart->use_empty()) { 1574ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey CallInst *CI = cast<CallInst>(RegionStart->use_back()); 1584ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey Value *Arg = CI->getOperand(1); 1594ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey assert(CI->use_empty() && "llvm.dbg intrinsic should have void result"); 1604ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey CI->eraseFromParent(); 1614ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey if (Arg->use_empty()) 1624ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Arg)) 1634ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey DeadGlobals.push_back(GV); 1644ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey } 1654ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey RegionStart->eraseFromParent(); 1664ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey } 167dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner if (RegionEnd) { 168dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner while (!RegionEnd->use_empty()) { 169dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner CallInst *CI = cast<CallInst>(RegionEnd->use_back()); 1704ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey Value *Arg = CI->getOperand(1); 1714ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey assert(CI->use_empty() && "llvm.dbg intrinsic should have void result"); 172dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner CI->eraseFromParent(); 1734ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey if (Arg->use_empty()) 1744ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Arg)) 1754ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey DeadGlobals.push_back(GV); 176dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner } 177dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner RegionEnd->eraseFromParent(); 178dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner } 1794ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey if (Declare) { 1804ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey while (!Declare->use_empty()) { 1814ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey CallInst *CI = cast<CallInst>(Declare->use_back()); 1824ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey Value *Arg = CI->getOperand(2); 1834ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey assert(CI->use_empty() && "llvm.dbg intrinsic should have void result"); 1844ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey CI->eraseFromParent(); 1854ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey if (Arg->use_empty()) 1864ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Arg)) 1874ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey DeadGlobals.push_back(GV); 1884ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey } 1894ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey Declare->eraseFromParent(); 1904ca9757a39a1bf3bd1264a77e52db62e02cc85fbJim Laskey } 191dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner 192dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner // Finally, delete any internal globals that were only used by the debugger 193dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner // intrinsics. 194dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner while (!DeadGlobals.empty()) { 195dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner GlobalVariable *GV = DeadGlobals.back(); 196dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner DeadGlobals.pop_back(); 197dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner if (GV->hasInternalLinkage()) 198dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner RemoveDeadConstant(GV); 199dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner } 200dd0ecf67316d68940fda2733faacf73b8bd22ec6Chris Lattner 201fd93908ae8b9684fe71c239e3c6cfe13ff6a2663Misha Brukman return true; 202e3ad43c828280cf11e8631f1a814a51a0b168016Chris Lattner} 203