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Diffstat (limited to 'contrib/llvm/lib/Transforms/Utils/MetaRenamer.cpp')
-rw-r--r-- | contrib/llvm/lib/Transforms/Utils/MetaRenamer.cpp | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Transforms/Utils/MetaRenamer.cpp b/contrib/llvm/lib/Transforms/Utils/MetaRenamer.cpp new file mode 100644 index 0000000..395a46b --- /dev/null +++ b/contrib/llvm/lib/Transforms/Utils/MetaRenamer.cpp @@ -0,0 +1,145 @@ +//===- MetaRenamer.cpp - Rename everything with metasyntatic names --------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This pass renames everything with metasyntatic names. The intent is to use +// this pass after bugpoint reduction to conceal the nature of the original +// program. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Transforms/IPO.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/Module.h" +#include "llvm/IR/Type.h" +#include "llvm/IR/TypeFinder.h" +#include "llvm/Pass.h" +using namespace llvm; + +namespace { + + // This PRNG is from the ISO C spec. It is intentionally simple and + // unsuitable for cryptographic use. We're just looking for enough + // variety to surprise and delight users. + struct PRNG { + unsigned long next; + + void srand(unsigned int seed) { + next = seed; + } + + int rand() { + next = next * 1103515245 + 12345; + return (unsigned int)(next / 65536) % 32768; + } + }; + + struct MetaRenamer : public ModulePass { + static char ID; // Pass identification, replacement for typeid + MetaRenamer() : ModulePass(ID) { + initializeMetaRenamerPass(*PassRegistry::getPassRegistry()); + } + + void getAnalysisUsage(AnalysisUsage &AU) const override { + AU.setPreservesAll(); + } + + bool runOnModule(Module &M) override { + static const char *const metaNames[] = { + // See http://en.wikipedia.org/wiki/Metasyntactic_variable + "foo", "bar", "baz", "quux", "barney", "snork", "zot", "blam", "hoge", + "wibble", "wobble", "widget", "wombat", "ham", "eggs", "pluto", "spam" + }; + + // Seed our PRNG with simple additive sum of ModuleID. We're looking to + // simply avoid always having the same function names, and we need to + // remain deterministic. + unsigned int randSeed = 0; + for (std::string::const_iterator I = M.getModuleIdentifier().begin(), + E = M.getModuleIdentifier().end(); I != E; ++I) + randSeed += *I; + + PRNG prng; + prng.srand(randSeed); + + // Rename all aliases + for (Module::alias_iterator AI = M.alias_begin(), AE = M.alias_end(); + AI != AE; ++AI) { + StringRef Name = AI->getName(); + if (Name.startswith("llvm.") || (!Name.empty() && Name[0] == 1)) + continue; + + AI->setName("alias"); + } + + // Rename all global variables + for (Module::global_iterator GI = M.global_begin(), GE = M.global_end(); + GI != GE; ++GI) { + StringRef Name = GI->getName(); + if (Name.startswith("llvm.") || (!Name.empty() && Name[0] == 1)) + continue; + + GI->setName("global"); + } + + // Rename all struct types + TypeFinder StructTypes; + StructTypes.run(M, true); + for (unsigned i = 0, e = StructTypes.size(); i != e; ++i) { + StructType *STy = StructTypes[i]; + if (STy->isLiteral() || STy->getName().empty()) continue; + + SmallString<128> NameStorage; + STy->setName((Twine("struct.") + metaNames[prng.rand() % + array_lengthof(metaNames)]).toStringRef(NameStorage)); + } + + // Rename all functions + for (Module::iterator FI = M.begin(), FE = M.end(); + FI != FE; ++FI) { + StringRef Name = FI->getName(); + if (Name.startswith("llvm.") || (!Name.empty() && Name[0] == 1)) + continue; + + FI->setName(metaNames[prng.rand() % array_lengthof(metaNames)]); + runOnFunction(*FI); + } + return true; + } + + bool runOnFunction(Function &F) { + for (Function::arg_iterator AI = F.arg_begin(), AE = F.arg_end(); + AI != AE; ++AI) + if (!AI->getType()->isVoidTy()) + AI->setName("arg"); + + for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { + BB->setName("bb"); + + for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) + if (!I->getType()->isVoidTy()) + I->setName("tmp"); + } + return true; + } + }; +} + +char MetaRenamer::ID = 0; +INITIALIZE_PASS(MetaRenamer, "metarenamer", + "Assign new names to everything", false, false) +//===----------------------------------------------------------------------===// +// +// MetaRenamer - Rename everything with metasyntactic names. +// +ModulePass *llvm::createMetaRenamerPass() { + return new MetaRenamer(); +} |