Remove Emscripten support

lib/Transforms/NaCl/NoExitRuntime.cpp

-//===- NoExitRuntime.cpp - Expand i64 and wider integer types -------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===------------------------------------------------------------------===//
-//
-//===------------------------------------------------------------------===//
-
-#include "llvm/ADT/PostOrderIterator.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/SmallString.h"
-#include "llvm/ADT/StringExtras.h"
-#include "llvm/Analysis/ConstantFolding.h"
-#include "llvm/Analysis/InstructionSimplify.h"
-#include "llvm/IR/DataLayout.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/IRBuilder.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/IR/CFG.h"
-#include "llvm/Analysis/TargetLibraryInfo.h"
-#include "llvm/Transforms/NaCl.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include <map>
-
-#include "llvm/Support/raw_ostream.h"
-
-#ifdef NDEBUG
-#undef assert
-#define assert(x) { if (!(x)) report_fatal_error(#x); }
-#endif
-
-using namespace llvm;
-
-namespace {
-  class NoExitRuntime : public ModulePass {
-    Module *TheModule;
-
-  public:
-    static char ID;
-    NoExitRuntime() : ModulePass(ID) {
-      initializeNoExitRuntimePass(*PassRegistry::getPassRegistry());
-    }
-
-    virtual bool runOnModule(Module &M);
-  };
-}
-
-char NoExitRuntime::ID = 0;
-INITIALIZE_PASS(NoExitRuntime, "emscripten-no-exit-runtime",
-                "Generate code which assumes the runtime is never exited (so atexit etc. is unneeded; see emscripten NO_EXIT_RUNTIME setting)",
-                false, false)
-
-
-// Implementation of NoExitRuntime
-
-bool NoExitRuntime::runOnModule(Module &M) {
-  TheModule = &M;
-
-  Function *AtExit = TheModule->getFunction("__cxa_atexit");
-  if (!AtExit || !AtExit->isDeclaration() || AtExit->getNumUses() == 0) return false;
-
-  // The system atexit is used - let's remove calls to it
-
-  Type *i32 = Type::getInt32Ty(TheModule->getContext());
-  Value *Zero  = Constant::getNullValue(i32);
-
-  std::vector<Instruction*> ToErase;
-
-  for (Instruction::user_iterator UI = AtExit->user_begin(), UE = AtExit->user_end(); UI != UE; ++UI) {
-    if (CallInst *CI = dyn_cast<CallInst>(*UI)) {
-      if (CI->getCalledValue() == AtExit) {
-        // calls to atexit can just be removed
-        CI->replaceAllUsesWith(Zero);
-        ToErase.push_back(CI);
-        continue;
-      }
-    }
-    // Possibly other uses of atexit are done - ptrtoint, etc. - but we leave those alone
-  }
-
-  for (unsigned i = 0; i < ToErase.size(); i++) {
-    ToErase[i]->eraseFromParent();
-  }
-
-  return true;
-}
-
-ModulePass *llvm::createNoExitRuntimePass() {
-  return new NoExitRuntime();
-}