Add a pass that renames everything with metasyntatic names. This works well after using bugpoint to reduce the confusion presented by the original names, which no longer mean what they used to.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163592 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 237 insertions, 0 deletions

diff --git a/include/llvm/InitializePasses.h b/include/llvm/InitializePasses.h
index bede4eb621..c1c833d949 100644
--- a/include/llvm/InitializePasses.h
+++ b/include/llvm/InitializePasses.h
@@ -178,6 +178,7 @@ void initializeMachineVerifierPassPass(PassRegistry&);
 void initializeMemCpyOptPass(PassRegistry&);
 void initializeMemDepPrinterPass(PassRegistry&);
 void initializeMemoryDependenceAnalysisPass(PassRegistry&);
+void initializeMetaRenamerPass(PassRegistry&);
 void initializeMergeFunctionsPass(PassRegistry&);
 void initializeModuleDebugInfoPrinterPass(PassRegistry&);
 void initializeNoAAPass(PassRegistry&);
diff --git a/include/llvm/LinkAllPasses.h b/include/llvm/LinkAllPasses.h
index fe4c92a295..c01e471024 100644
--- a/include/llvm/LinkAllPasses.h
+++ b/include/llvm/LinkAllPasses.h
@@ -141,6 +141,7 @@ namespace {
       (void) llvm::createLoopDeletionPass();
       (void) llvm::createPostDomTree();
       (void) llvm::createInstructionNamerPass();
+      (void) llvm::createMetaRenamerPass();
       (void) llvm::createFunctionAttrsPass();
       (void) llvm::createMergeFunctionsPass();
       (void) llvm::createPrintModulePass(0);
diff --git a/include/llvm/Transforms/IPO.h b/include/llvm/Transforms/IPO.h
index 18176e8fdb..962cb63758 100644
--- a/include/llvm/Transforms/IPO.h
+++ b/include/llvm/Transforms/IPO.h
@@ -192,6 +192,11 @@ ModulePass *createMergeFunctionsPass();
 /// createPartialInliningPass - This pass inlines parts of functions.
 ///
 ModulePass *createPartialInliningPass();
+  
+//===----------------------------------------------------------------------===//
+// createMetaRenamerPass - Rename everything with metasyntatic names.
+//
+ModulePass *createMetaRenamerPass();
 
 } // End llvm namespace
 
diff --git a/lib/Transforms/Utils/MetaRenamer.cpp b/lib/Transforms/Utils/MetaRenamer.cpp
new file mode 100644
index 0000000000..60f031e16f
--- /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/Transforms/IPO.h"
+#include "llvm/Function.h"
+#include "llvm/Module.h"
+#include "llvm/Pass.h"
+#include "llvm/Type.h"
+#include "llvm/TypeFinder.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.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();
+}
diff --git a/lib/Transforms/Utils/Utils.cpp b/lib/Transforms/Utils/Utils.cpp
index 24e8c8ff5c..5812d4607d 100644
--- a/lib/Transforms/Utils/Utils.cpp
+++ b/lib/Transforms/Utils/Utils.cpp
@@ -29,6 +29,7 @@ void llvm::initializeTransformUtils(PassRegistry &Registry) {
   initializePromotePassPass(Registry);
   initializeUnifyFunctionExitNodesPass(Registry);
   initializeInstSimplifierPass(Registry);
+  initializeMetaRenamerPass(Registry);
 }
 
 /// LLVMInitializeTransformUtils - C binding for initializeTransformUtilsPasses.
diff --git a/test/Transforms/MetaRenamer/lit.local.cfg b/test/Transforms/MetaRenamer/lit.local.cfg
new file mode 100644
index 0000000000..19eebc0ac7
--- /dev/null
+++ b/test/Transforms/MetaRenamer/lit.local.cfg
@@ -0,0 +1 @@
+config.suffixes = ['.ll', '.c', '.cpp']
diff --git a/test/Transforms/MetaRenamer/metarenamer.ll b/test/Transforms/MetaRenamer/metarenamer.ll
new file mode 100644
index 0000000000..ad41bcf50f
--- /dev/null
+++ b/test/Transforms/MetaRenamer/metarenamer.ll
@@ -0,0 +1,96 @@
+; RUN: opt %s -metarenamer -S | FileCheck %s
+
+; CHECK: target triple {{.*}}
+; CHECK-NOT: {{^x*}}xxx{{^x*}}
+; CHECK: ret i32 6
+
+target triple = "x86_64-pc-linux-gnu"
+
+%struct.bar_xxx = type { i32, double }
+%struct.foo_xxx = type { i32, float, %struct.bar_xxx }
+
+@func_5_xxx.static_local_3_xxx = internal global i32 3, align 4
+@global_3_xxx = common global i32 0, align 4
+
+@func_7_xxx = alias weak i32 (...)* @aliased_func_7_xxx
+
+declare i32 @aliased_func_7_xxx(...)
+
+define i32 @func_3_xxx() nounwind uwtable ssp {
+  ret i32 3
+}
+
+define void @func_4_xxx(%struct.foo_xxx* sret %agg.result) nounwind uwtable ssp {
+  %1 = alloca %struct.foo_xxx, align 8
+  %2 = getelementptr inbounds %struct.foo_xxx* %1, i32 0, i32 0
+  store i32 1, i32* %2, align 4
+  %3 = getelementptr inbounds %struct.foo_xxx* %1, i32 0, i32 1
+  store float 2.000000e+00, float* %3, align 4
+  %4 = getelementptr inbounds %struct.foo_xxx* %1, i32 0, i32 2
+  %5 = getelementptr inbounds %struct.bar_xxx* %4, i32 0, i32 0
+  store i32 3, i32* %5, align 4
+  %6 = getelementptr inbounds %struct.bar_xxx* %4, i32 0, i32 1
+  store double 4.000000e+00, double* %6, align 8
+  %7 = bitcast %struct.foo_xxx* %agg.result to i8*
+  %8 = bitcast %struct.foo_xxx* %1 to i8*
+  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %7, i8* %8, i64 24, i32 8, i1 false)
+  ret void
+}
+
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
+
+define i32 @func_5_xxx(i32 %arg_1_xxx, i32 %arg_2_xxx, i32 %arg_3_xxx, i32 %arg_4_xxx) nounwind uwtable ssp {
+  %1 = alloca i32, align 4
+  %2 = alloca i32, align 4
+  %3 = alloca i32, align 4
+  %4 = alloca i32, align 4
+  %local_1_xxx = alloca i32, align 4
+  %local_2_xxx = alloca i32, align 4
+  %i = alloca i32, align 4
+  store i32 %arg_1_xxx, i32* %1, align 4
+  store i32 %arg_2_xxx, i32* %2, align 4
+  store i32 %arg_3_xxx, i32* %3, align 4
+  store i32 %arg_4_xxx, i32* %4, align 4
+  store i32 1, i32* %local_1_xxx, align 4
+  store i32 2, i32* %local_2_xxx, align 4
+  store i32 0, i32* %i, align 4
+  br label %5
+
+; <label>:5                                       ; preds = %9, %0
+  %6 = load i32* %i, align 4
+  %7 = icmp slt i32 %6, 10
+  br i1 %7, label %8, label %12
+
+; <label>:8                                       ; preds = %5
+  br label %9
+
+; <label>:9                                       ; preds = %8
+  %10 = load i32* %i, align 4
+  %11 = add nsw i32 %10, 1
+  store i32 %11, i32* %i, align 4
+  br label %5
+
+; <label>:12                                      ; preds = %5
+  %13 = load i32* %local_1_xxx, align 4
+  %14 = load i32* %1, align 4
+  %15 = add nsw i32 %13, %14
+  %16 = load i32* %local_2_xxx, align 4
+  %17 = add nsw i32 %15, %16
+  %18 = load i32* %2, align 4
+  %19 = add nsw i32 %17, %18
+  %20 = load i32* @func_5_xxx.static_local_3_xxx, align 4
+  %21 = add nsw i32 %19, %20
+  %22 = load i32* %3, align 4
+  %23 = add nsw i32 %21, %22
+  %24 = load i32* %4, align 4
+  %25 = add nsw i32 %23, %24
+  ret i32 %25
+}
+
+define i32 @varargs_func_6_xxx(i32 %arg_1_xxx, i32 %arg_2_xxx, ...) nounwind uwtable ssp {
+  %1 = alloca i32, align 4
+  %2 = alloca i32, align 4
+  store i32 %arg_1_xxx, i32* %1, align 4
+  store i32 %arg_2_xxx, i32* %2, align 4
+  ret i32 6
+}