1 //===- SymbolStripping.cpp - Strip symbols for functions and modules ------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements stripping symbols out of symbol tables.
12 // Specifically, this allows you to strip all of the symbols out of:
14 // * All functions in a module
15 // * All symbols in a module (all function symbols + all module scope symbols)
18 // * This pass makes code much less readable, so it should only be used in
19 // situations where the 'strip' utility would be used (such as reducing
20 // code size, and making it harder to reverse engineer code).
22 //===----------------------------------------------------------------------===//
24 #include "llvm/Transforms/Scalar.h"
25 #include "llvm/Module.h"
26 #include "llvm/SymbolTable.h"
27 #include "llvm/Pass.h"
29 static bool StripSymbolTable(SymbolTable &SymTab) {
30 bool RemovedSymbol = false;
32 for (SymbolTable::iterator I = SymTab.begin(); I != SymTab.end(); ++I) {
33 std::map<const std::string, Value *> &Plane = I->second;
35 SymbolTable::type_iterator B;
36 while ((B = Plane.begin()) != Plane.end()) { // Found nonempty type plane!
38 if (isa<Constant>(V) || isa<Type>(V))
39 SymTab.type_remove(B);
41 V->setName("", &SymTab); // Set name to "", removing from symbol table!
43 assert(Plane.begin() != B && "Symbol not removed from table!");
51 struct SymbolStripping : public FunctionPass {
52 virtual bool runOnFunction(Function &F) {
53 return StripSymbolTable(F.getSymbolTable());
55 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
59 RegisterOpt<SymbolStripping> X("strip", "Strip symbols from functions");
61 struct FullSymbolStripping : public SymbolStripping {
62 virtual bool doInitialization(Module &M) {
63 return StripSymbolTable(M.getSymbolTable());
66 RegisterOpt<FullSymbolStripping> Y("mstrip",
67 "Strip symbols from module and functions");
70 Pass *createSymbolStrippingPass() {
71 return new SymbolStripping();
74 Pass *createFullSymbolStrippingPass() {
75 return new FullSymbolStripping();