vendor/llvm/llvm-release_32-r168974

1 files changed, 132 insertions, 0 deletions

diff --git a/lib/Transforms/Utils/MetaRenamer.cpp b/lib/Transforms/Utils/MetaRenamer.cpp
new file mode 100644
index 000000000000..233bc12d3cfd
--- /dev/null
+++ b/lib/Transforms/Utils/MetaRenamer.cpp
@@ -0,0 +1,132 @@
+//===- 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/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Transforms/IPO.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/Module.h"
+#include "llvm/Pass.h"
+#include "llvm/Type.h"
+#include "llvm/TypeFinder.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(void) {
+      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 {
+      AU.setPreservesAll();
+    }
+
+    bool runOnModule(Module &M) {
+      static const char *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)
+        AI->setName("alias");
+
+      // Rename all global variables
+      for (Module::global_iterator GI = M.global_begin(), GE = M.global_end();
+           GI != GE; ++GI)
+        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) {
+        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();
+}