Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 1 | //===- StripSymbols.cpp - Strip symbols and debug info from a module ------===// |
Misha Brukman | fd93908 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 2 | // |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
Chris Lattner | 4ee451d | 2007-12-29 20:36:04 +0000 | [diff] [blame^] | 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
Misha Brukman | fd93908 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 7 | // |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
Gordon Henriksen | c86b677 | 2007-11-04 16:15:04 +0000 | [diff] [blame] | 10 | // The StripSymbols transformation implements code stripping. Specifically, it |
| 11 | // can delete: |
| 12 | // |
| 13 | // * names for virtual registers |
| 14 | // * symbols for internal globals and functions |
| 15 | // * debug information |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 16 | // |
Gordon Henriksen | c86b677 | 2007-11-04 16:15:04 +0000 | [diff] [blame] | 17 | // Note that this transformation makes code much less readable, so it should |
| 18 | // only be used in situations where the 'strip' utility would be used, such as |
| 19 | // reducing code size or making it harder to reverse engineer code. |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 20 | // |
| 21 | //===----------------------------------------------------------------------===// |
| 22 | |
| 23 | #include "llvm/Transforms/IPO.h" |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 24 | #include "llvm/Constants.h" |
| 25 | #include "llvm/DerivedTypes.h" |
| 26 | #include "llvm/Instructions.h" |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 27 | #include "llvm/Module.h" |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 28 | #include "llvm/Pass.h" |
Reid Spencer | ef9b9a7 | 2007-02-05 20:47:22 +0000 | [diff] [blame] | 29 | #include "llvm/ValueSymbolTable.h" |
Reid Spencer | 78d033e | 2007-01-06 07:24:44 +0000 | [diff] [blame] | 30 | #include "llvm/TypeSymbolTable.h" |
Reid Spencer | 9133fe2 | 2007-02-05 23:32:05 +0000 | [diff] [blame] | 31 | #include "llvm/Support/Compiler.h" |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 32 | using namespace llvm; |
| 33 | |
| 34 | namespace { |
Reid Spencer | 9133fe2 | 2007-02-05 23:32:05 +0000 | [diff] [blame] | 35 | class VISIBILITY_HIDDEN StripSymbols : public ModulePass { |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 36 | bool OnlyDebugInfo; |
| 37 | public: |
Nick Lewycky | ecd94c8 | 2007-05-06 13:37:16 +0000 | [diff] [blame] | 38 | static char ID; // Pass identification, replacement for typeid |
Dan Gohman | c2bbfc1 | 2007-08-01 15:32:29 +0000 | [diff] [blame] | 39 | explicit StripSymbols(bool ODI = false) |
Devang Patel | 794fd75 | 2007-05-01 21:15:47 +0000 | [diff] [blame] | 40 | : ModulePass((intptr_t)&ID), OnlyDebugInfo(ODI) {} |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 41 | |
| 42 | virtual bool runOnModule(Module &M); |
| 43 | |
| 44 | virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
| 45 | AU.setPreservesAll(); |
| 46 | } |
| 47 | }; |
Devang Patel | 794fd75 | 2007-05-01 21:15:47 +0000 | [diff] [blame] | 48 | |
Devang Patel | 1997473 | 2007-05-03 01:11:54 +0000 | [diff] [blame] | 49 | char StripSymbols::ID = 0; |
Chris Lattner | 7f8897f | 2006-08-27 22:42:52 +0000 | [diff] [blame] | 50 | RegisterPass<StripSymbols> X("strip", "Strip all symbols from a module"); |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 51 | } |
| 52 | |
| 53 | ModulePass *llvm::createStripSymbolsPass(bool OnlyDebugInfo) { |
| 54 | return new StripSymbols(OnlyDebugInfo); |
| 55 | } |
| 56 | |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 57 | static void RemoveDeadConstant(Constant *C) { |
| 58 | assert(C->use_empty() && "Constant is not dead!"); |
| 59 | std::vector<Constant*> Operands; |
| 60 | for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i) |
| 61 | if (isa<DerivedType>(C->getOperand(i)->getType()) && |
| 62 | C->getOperand(i)->hasOneUse()) |
| 63 | Operands.push_back(C->getOperand(i)); |
| 64 | if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) { |
| 65 | if (!GV->hasInternalLinkage()) return; // Don't delete non static globals. |
| 66 | GV->eraseFromParent(); |
| 67 | } |
| 68 | else if (!isa<Function>(C)) |
| 69 | C->destroyConstant(); |
Misha Brukman | fd93908 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 70 | |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 71 | // If the constant referenced anything, see if we can delete it as well. |
| 72 | while (!Operands.empty()) { |
| 73 | RemoveDeadConstant(Operands.back()); |
| 74 | Operands.pop_back(); |
| 75 | } |
| 76 | } |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 77 | |
Chris Lattner | 7f1444b | 2007-02-07 06:22:45 +0000 | [diff] [blame] | 78 | // Strip the symbol table of its names. |
| 79 | // |
| 80 | static void StripSymtab(ValueSymbolTable &ST) { |
| 81 | for (ValueSymbolTable::iterator VI = ST.begin(), VE = ST.end(); VI != VE; ) { |
Chris Lattner | dec628e | 2007-02-12 05:18:08 +0000 | [diff] [blame] | 82 | Value *V = VI->getValue(); |
Chris Lattner | 7f1444b | 2007-02-07 06:22:45 +0000 | [diff] [blame] | 83 | ++VI; |
| 84 | if (!isa<GlobalValue>(V) || cast<GlobalValue>(V)->hasInternalLinkage()) { |
| 85 | // Set name to "", removing from symbol table! |
| 86 | V->setName(""); |
| 87 | } |
| 88 | } |
| 89 | } |
| 90 | |
| 91 | // Strip the symbol table of its names. |
| 92 | static void StripTypeSymtab(TypeSymbolTable &ST) { |
| 93 | for (TypeSymbolTable::iterator TI = ST.begin(), E = ST.end(); TI != E; ) |
| 94 | ST.remove(TI++); |
| 95 | } |
| 96 | |
| 97 | |
| 98 | |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 99 | bool StripSymbols::runOnModule(Module &M) { |
| 100 | // If we're not just stripping debug info, strip all symbols from the |
| 101 | // functions and the names from any internal globals. |
| 102 | if (!OnlyDebugInfo) { |
Chris Lattner | 7f8897f | 2006-08-27 22:42:52 +0000 | [diff] [blame] | 103 | for (Module::global_iterator I = M.global_begin(), E = M.global_end(); |
| 104 | I != E; ++I) |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 105 | if (I->hasInternalLinkage()) |
| 106 | I->setName(""); // Internal symbols can't participate in linkage |
| 107 | |
| 108 | for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) { |
| 109 | if (I->hasInternalLinkage()) |
| 110 | I->setName(""); // Internal symbols can't participate in linkage |
Chris Lattner | 7f1444b | 2007-02-07 06:22:45 +0000 | [diff] [blame] | 111 | StripSymtab(I->getValueSymbolTable()); |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 112 | } |
Chris Lattner | b2f6c00 | 2006-03-15 19:22:41 +0000 | [diff] [blame] | 113 | |
| 114 | // Remove all names from types. |
Chris Lattner | 7f1444b | 2007-02-07 06:22:45 +0000 | [diff] [blame] | 115 | StripTypeSymtab(M.getTypeSymbolTable()); |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 116 | } |
| 117 | |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 118 | // Strip debug info in the module if it exists. To do this, we remove |
| 119 | // llvm.dbg.func.start, llvm.dbg.stoppoint, and llvm.dbg.region.end calls, and |
| 120 | // any globals they point to if now dead. |
Reid Spencer | 688b049 | 2007-02-05 21:19:13 +0000 | [diff] [blame] | 121 | Function *FuncStart = M.getFunction("llvm.dbg.func.start"); |
| 122 | Function *StopPoint = M.getFunction("llvm.dbg.stoppoint"); |
| 123 | Function *RegionStart = M.getFunction("llvm.dbg.region.start"); |
| 124 | Function *RegionEnd = M.getFunction("llvm.dbg.region.end"); |
| 125 | Function *Declare = M.getFunction("llvm.dbg.declare"); |
Jim Laskey | 4ca9757 | 2006-03-23 18:11:33 +0000 | [diff] [blame] | 126 | if (!FuncStart && !StopPoint && !RegionStart && !RegionEnd && !Declare) |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 127 | return true; |
| 128 | |
| 129 | std::vector<GlobalVariable*> DeadGlobals; |
| 130 | |
| 131 | // Remove all of the calls to the debugger intrinsics, and remove them from |
| 132 | // the module. |
| 133 | if (FuncStart) { |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 134 | while (!FuncStart->use_empty()) { |
| 135 | CallInst *CI = cast<CallInst>(FuncStart->use_back()); |
| 136 | Value *Arg = CI->getOperand(1); |
Jim Laskey | 4ca9757 | 2006-03-23 18:11:33 +0000 | [diff] [blame] | 137 | assert(CI->use_empty() && "llvm.dbg intrinsic should have void result"); |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 138 | CI->eraseFromParent(); |
| 139 | if (Arg->use_empty()) |
| 140 | if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Arg)) |
| 141 | DeadGlobals.push_back(GV); |
| 142 | } |
| 143 | FuncStart->eraseFromParent(); |
| 144 | } |
| 145 | if (StopPoint) { |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 146 | while (!StopPoint->use_empty()) { |
| 147 | CallInst *CI = cast<CallInst>(StopPoint->use_back()); |
Jim Laskey | f4321a3 | 2006-03-13 13:07:37 +0000 | [diff] [blame] | 148 | Value *Arg = CI->getOperand(3); |
Jim Laskey | 4ca9757 | 2006-03-23 18:11:33 +0000 | [diff] [blame] | 149 | assert(CI->use_empty() && "llvm.dbg intrinsic should have void result"); |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 150 | CI->eraseFromParent(); |
| 151 | if (Arg->use_empty()) |
| 152 | if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Arg)) |
| 153 | DeadGlobals.push_back(GV); |
| 154 | } |
| 155 | StopPoint->eraseFromParent(); |
| 156 | } |
Jim Laskey | 4ca9757 | 2006-03-23 18:11:33 +0000 | [diff] [blame] | 157 | if (RegionStart) { |
| 158 | while (!RegionStart->use_empty()) { |
| 159 | CallInst *CI = cast<CallInst>(RegionStart->use_back()); |
| 160 | Value *Arg = CI->getOperand(1); |
| 161 | assert(CI->use_empty() && "llvm.dbg intrinsic should have void result"); |
| 162 | CI->eraseFromParent(); |
| 163 | if (Arg->use_empty()) |
| 164 | if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Arg)) |
| 165 | DeadGlobals.push_back(GV); |
| 166 | } |
| 167 | RegionStart->eraseFromParent(); |
| 168 | } |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 169 | if (RegionEnd) { |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 170 | while (!RegionEnd->use_empty()) { |
| 171 | CallInst *CI = cast<CallInst>(RegionEnd->use_back()); |
Jim Laskey | 4ca9757 | 2006-03-23 18:11:33 +0000 | [diff] [blame] | 172 | Value *Arg = CI->getOperand(1); |
| 173 | assert(CI->use_empty() && "llvm.dbg intrinsic should have void result"); |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 174 | CI->eraseFromParent(); |
Jim Laskey | 4ca9757 | 2006-03-23 18:11:33 +0000 | [diff] [blame] | 175 | if (Arg->use_empty()) |
| 176 | if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Arg)) |
| 177 | DeadGlobals.push_back(GV); |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 178 | } |
| 179 | RegionEnd->eraseFromParent(); |
| 180 | } |
Jim Laskey | 4ca9757 | 2006-03-23 18:11:33 +0000 | [diff] [blame] | 181 | if (Declare) { |
| 182 | while (!Declare->use_empty()) { |
| 183 | CallInst *CI = cast<CallInst>(Declare->use_back()); |
| 184 | Value *Arg = CI->getOperand(2); |
| 185 | assert(CI->use_empty() && "llvm.dbg intrinsic should have void result"); |
| 186 | CI->eraseFromParent(); |
| 187 | if (Arg->use_empty()) |
| 188 | if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Arg)) |
| 189 | DeadGlobals.push_back(GV); |
| 190 | } |
| 191 | Declare->eraseFromParent(); |
| 192 | } |
Chris Lattner | dd0ecf6 | 2004-12-03 16:22:08 +0000 | [diff] [blame] | 193 | |
| 194 | // Finally, delete any internal globals that were only used by the debugger |
| 195 | // intrinsics. |
| 196 | while (!DeadGlobals.empty()) { |
| 197 | GlobalVariable *GV = DeadGlobals.back(); |
| 198 | DeadGlobals.pop_back(); |
| 199 | if (GV->hasInternalLinkage()) |
| 200 | RemoveDeadConstant(GV); |
| 201 | } |
| 202 | |
Misha Brukman | fd93908 | 2005-04-21 23:48:37 +0000 | [diff] [blame] | 203 | return true; |
Chris Lattner | e3ad43c | 2004-12-02 21:25:03 +0000 | [diff] [blame] | 204 | } |