| //===- SymbolStripping.cpp - Strip symbols for functions and modules ------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and is distributed under |
| // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements stripping symbols out of symbol tables. |
| // |
| // Specifically, this allows you to strip all of the symbols out of: |
| // * A function |
| // * All functions in a module |
| // * All symbols in a module (all function symbols + all module scope symbols) |
| // |
| // Notice that: |
| // * This pass makes code much less readable, so it should only be used in |
| // situations where the 'strip' utility would be used (such as reducing |
| // code size, and making it harder to reverse engineer code). |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Transforms/Scalar.h" |
| #include "llvm/Module.h" |
| #include "llvm/SymbolTable.h" |
| #include "llvm/Pass.h" |
| |
| static bool StripSymbolTable(SymbolTable &SymTab) { |
| bool RemovedSymbol = false; |
| |
| for (SymbolTable::iterator I = SymTab.begin(); I != SymTab.end(); ++I) { |
| std::map<const std::string, Value *> &Plane = I->second; |
| |
| SymbolTable::type_iterator B; |
| while ((B = Plane.begin()) != Plane.end()) { // Found nonempty type plane! |
| Value *V = B->second; |
| if (isa<Constant>(V) || isa<Type>(V)) |
| SymTab.type_remove(B); |
| else |
| V->setName("", &SymTab); // Set name to "", removing from symbol table! |
| RemovedSymbol = true; |
| assert(Plane.begin() != B && "Symbol not removed from table!"); |
| } |
| } |
| |
| return RemovedSymbol; |
| } |
| |
| namespace { |
| struct SymbolStripping : public FunctionPass { |
| virtual bool runOnFunction(Function &F) { |
| return StripSymbolTable(F.getSymbolTable()); |
| } |
| virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
| AU.setPreservesAll(); |
| } |
| }; |
| RegisterOpt<SymbolStripping> X("strip", "Strip symbols from functions"); |
| |
| struct FullSymbolStripping : public SymbolStripping { |
| virtual bool doInitialization(Module &M) { |
| return StripSymbolTable(M.getSymbolTable()); |
| } |
| }; |
| RegisterOpt<FullSymbolStripping> Y("mstrip", |
| "Strip symbols from module and functions"); |
| } |
| |
| Pass *createSymbolStrippingPass() { |
| return new SymbolStripping(); |
| } |
| |
| Pass *createFullSymbolStrippingPass() { |
| return new FullSymbolStripping(); |
| } |