1 //===- StripSymbols.cpp - Strip symbols and debug info from a module ------===//
3 //                     The LLVM Compiler Infrastructure
8 //===----------------------------------------------------------------------===//
18 // only be used in situations where the 'strip' utility would be used, such as
21 //===----------------------------------------------------------------------===//
23 #include "llvm/Transforms/IPO.h"
24 #include "llvm/ADT/SmallPtrSet.h"
25 #include "llvm/IR/Constants.h"
26 #include "llvm/IR/DebugInfo.h"
27 #include "llvm/IR/DerivedTypes.h"
28 #include "llvm/IR/Instructions.h"
29 #include "llvm/IR/Module.h"
30 #include "llvm/IR/TypeFinder.h"
31 #include "llvm/IR/ValueSymbolTable.h"
32 #include "llvm/Pass.h"
33 #include "llvm/Transforms/Utils/Local.h"
34 using namespace llvm;
100 INITIALIZE_PASS(StripSymbols, "strip",
101                 "Strip all symbols from a module", false, false)
103 ModulePass *llvm::createStripSymbolsPass(bool OnlyDebugInfo) {  in createStripSymbolsPass()
108 INITIALIZE_PASS(StripNonDebugSymbols, "strip-nondebug",
109                 "Strip all symbols, except dbg symbols, from a module",
112 ModulePass *llvm::createStripNonDebugSymbolsPass() {  in createStripNonDebugSymbolsPass()
117 INITIALIZE_PASS(StripDebugDeclare, "strip-debug-declare",
118                 "Strip all llvm.dbg.declare intrinsics", false, false)
120 ModulePass *llvm::createStripDebugDeclarePass() {  in createStripDebugDeclarePass()
125 INITIALIZE_PASS(StripDeadDebugInfo, "strip-dead-debug-info",
126                 "Strip debug info for unused symbols", false, false)
128 ModulePass *llvm::createStripDeadDebugInfoPass() {  in createStripDeadDebugInfoPass()
132 /// OnlyUsedBy - Return true if V is only used by Usr.
134   for (User *U : V->users())  in OnlyUsedBy()
142   assert(C->use_empty() && "Constant is not dead!");  in RemoveDeadConstant()
144   for (Value *Op : C->operands())  in RemoveDeadConstant()
148     if (!GV->hasLocalLinkage()) return;   // Don't delete non-static globals.  in RemoveDeadConstant()
149     GV->eraseFromParent();  in RemoveDeadConstant()
152     if (isa<CompositeType>(C->getType()))  in RemoveDeadConstant()
153       C->destroyConstant();  in RemoveDeadConstant()
160 // Strip the symbol table of its names.
164     Value *V = VI->getValue();  in StripSymtab()
166     if (!isa<GlobalValue>(V) || cast<GlobalValue>(V)->hasLocalLinkage()) {  in StripSymtab()
167       if (!PreserveDbgInfo || !V->getName().startswith("llvm.dbg"))  in StripSymtab()
169         V->setName("");  in StripSymtab()
174 // Strip any named types of their names.
181     if (STy->isLiteral() || STy->getName().empty()) continue;  in StripTypeNames()
183     if (PreserveDbgInfo && STy->getName().startswith("llvm.dbg"))  in StripTypeNames()
186     STy->setName("");  in StripTypeNames()
190 /// Find values that are marked as llvm.used.
196   ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());  in findUsedValues()
198   for (unsigned i = 0, e = Inits->getNumOperands(); i != e; ++i)  in findUsedValues()
200           dyn_cast<GlobalValue>(Inits->getOperand(i)->stripPointerCasts()))  in findUsedValues()
204 /// StripSymbolNames - Strip symbol names.
208   findUsedValues(M.getGlobalVariable("llvm.used"), llvmUsedValues);  in StripSymbolNames()
209   findUsedValues(M.getGlobalVariable("llvm.compiler.used"), llvmUsedValues);  in StripSymbolNames()
213     if (I->hasLocalLinkage() && llvmUsedValues.count(&*I) == 0)  in StripSymbolNames()
214       if (!PreserveDbgInfo || !I->getName().startswith("llvm.dbg"))  in StripSymbolNames()
215         I->setName("");     // Internal symbols can't participate in linkage  in StripSymbolNames()
220       if (!PreserveDbgInfo || !I.getName().startswith("llvm.dbg"))  in StripSymbolNames()
253   Function *Declare = M.getFunction("llvm.dbg.declare");  in runOnModule()
257     while (!Declare->use_empty()) {  in runOnModule()
258       CallInst *CI = cast<CallInst>(Declare->user_back());  in runOnModule()
259       Value *Arg1 = CI->getArgOperand(0);  in runOnModule()
260       Value *Arg2 = CI->getArgOperand(1);  in runOnModule()
261       assert(CI->use_empty() && "llvm.dbg intrinsic should have void result");  in runOnModule()
262       CI->eraseFromParent();  in runOnModule()
263       if (Arg1->use_empty()) {  in runOnModule()
269       if (Arg2->use_empty())  in runOnModule()
273     Declare->eraseFromParent();  in runOnModule()
280       if (GV->hasLocalLinkage())  in runOnModule()
292 /// Debugging information is encoded in llvm IR using metadata. This is designed
327     for (DIGlobalVariable *DIG : DIC->getGlobalVariables()) {  in runOnModule()
334       if (DIG->getVariable())  in runOnModule()
343       DIC->replaceGlobalVariables(MDTuple::get(C, LiveGlobalVariables));  in runOnModule()