Remove Emscripten support

lib/Transforms/NaCl/LowerEmExceptionsPass.cpp

Index: lib/Transforms/NaCl/LowerEmExceptionsPass.cpp
diff --git a/lib/Transforms/NaCl/LowerEmExceptionsPass.cpp b/lib/Transforms/NaCl/LowerEmExceptionsPass.cpp
deleted file mode 100644
index 676a0a68050e648f3e6f53bf4b1f93b3948a3322..0000000000000000000000000000000000000000
--- a/lib/Transforms/NaCl/LowerEmExceptionsPass.cpp
+++ /dev/null
@@ -1,272 +0,0 @@
-//===- LowerEmExceptions - Lower exceptions for Emscripten/JS   -----------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This is based off the 'cheap' version of LowerInvoke. It does two things:
-//
-//  1) Lower
-//         invoke() to l1 unwind l2
-//     into
-//         preinvoke(); // (will clear __THREW__)
-//         call();
-//         threw = postinvoke(); (check __THREW__)
-//         br threw, l1, l2
-//
-//     We do this to avoid introducing a new LLVM IR type, or to try to reuse
-//     invoke-landingpad for our special purposes (as they are checked very
-//     carefully by llvm)
-//
-//  2) Lower landingpads to a call to emscripten_landingpad
-//
-//  3) Lower resume to emscripten_resume which receives non-aggregate inputs
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Transforms/Scalar.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/Intrinsics.h"
-#include "llvm/IR/LLVMContext.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Target/TargetLowering.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Transforms/NaCl.h"
-#include "llvm/Support/raw_ostream.h"
-
-#include <vector>
-#include <set>
-
-#ifdef NDEBUG
-#undef assert
-#define assert(x) { if (!(x)) report_fatal_error(#x); }
-#endif
-
-using namespace llvm;
-
-static cl::list<std::string>
-Whitelist("emscripten-cxx-exceptions-whitelist",
-          cl::desc("Enables C++ exceptions in emscripten (see emscripten EXCEPTION_CATCHING_WHITELIST option)"),
-          cl::CommaSeparated);
-
-namespace {
-  class LowerEmExceptions : public ModulePass {
-    Function *GetHigh, *PreInvoke, *PostInvoke, *LandingPad, *Resume;
-    Module *TheModule;
-
-  public:
-    static char ID; // Pass identification, replacement for typeid
-    explicit LowerEmExceptions() : ModulePass(ID), GetHigh(NULL), PreInvoke(NULL), PostInvoke(NULL), LandingPad(NULL), Resume(NULL), TheModule(NULL) {
-      initializeLowerEmExceptionsPass(*PassRegistry::getPassRegistry());
-    }
-    bool runOnModule(Module &M);
-  };
-}
-
-char LowerEmExceptions::ID = 0;
-INITIALIZE_PASS(LowerEmExceptions, "loweremexceptions",
-                "Lower invoke and unwind for js/emscripten",
-                false, false)
-
-bool canThrow(Value *V) {
-  if (Function *F = dyn_cast<Function>(V)) {
-    // intrinsics and some emscripten builtins cannot throw
-    if (F->isIntrinsic()) return false;
-    StringRef Name = F->getName();
-    if (Name.startswith("emscripten_asm_")) return false;
-    if (Name == "setjmp" || Name == "longjmp") return false; // leave setjmp and longjmp (mostly) alone, we process them properly later
-    return true;
-  }
-  return true; // not a function, so an indirect call - can throw, we can't tell
-}
-
-bool LowerEmExceptions::runOnModule(Module &M) {
-  TheModule = &M;
-
-  // Add functions
-
-  Type *i32 = Type::getInt32Ty(M.getContext());
-  Type *i8 = Type::getInt8Ty(M.getContext());
-  Type *i1 = Type::getInt1Ty(M.getContext());
-  Type *i8P = i8->getPointerTo();
-  Type *Void = Type::getVoidTy(M.getContext());
-
-  if (!(GetHigh = TheModule->getFunction("getHigh32"))) {
-    FunctionType *GetHighFunc = FunctionType::get(i32, false);
-    GetHigh = Function::Create(GetHighFunc, GlobalValue::ExternalLinkage,
-                               "getHigh32", TheModule);
-  }
-
-  if (!(PreInvoke = TheModule->getFunction("emscripten_preinvoke"))) {
-    FunctionType *VoidFunc = FunctionType::get(Void, false);
-    PreInvoke = Function::Create(VoidFunc, GlobalValue::ExternalLinkage, "emscripten_preinvoke", TheModule);
-  }
-
-  if (!(PostInvoke = TheModule->getFunction("emscripten_postinvoke"))) {
-    FunctionType *IntFunc = FunctionType::get(i32, false);
-    PostInvoke = Function::Create(IntFunc, GlobalValue::ExternalLinkage, "emscripten_postinvoke", TheModule);
-  }
-
-  FunctionType *LandingPadFunc = FunctionType::get(i8P, true);
-  LandingPad = Function::Create(LandingPadFunc, GlobalValue::ExternalLinkage, "emscripten_landingpad", TheModule);
-
-  FunctionType *ResumeFunc = FunctionType::get(Void, true);
-  Resume = Function::Create(ResumeFunc, GlobalValue::ExternalLinkage, "emscripten_resume", TheModule);
-  
-  // Process
-
-  std::set<std::string> WhitelistSet(Whitelist.begin(), Whitelist.end());
-
-  bool Changed = false;
-
-  for (Module::iterator Iter = M.begin(), E = M.end(); Iter != E; ) {
-    Function *F = Iter++;
-
-    std::vector<Instruction*> ToErase;
-    std::set<LandingPadInst*> LandingPads;
-
-    bool AllowExceptionsInFunc = WhitelistSet.empty() || (WhitelistSet.count("_" + F->getName().str()) != 0);
-
-    for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
-      // check terminator for invokes
-      if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator())) {
-        LandingPads.insert(II->getLandingPadInst());
-
-        bool NeedInvoke = AllowExceptionsInFunc && canThrow(II->getCalledValue());
-
-        if (NeedInvoke) {
-          // If we are calling a function that is noreturn, we must remove that attribute. The code we
-          // insert here does expect it to return, after we catch the exception.
-          if (II->doesNotReturn()) {
-            if (Function *F = dyn_cast<Function>(II->getCalledValue())) {
-              F->removeFnAttr(Attribute::NoReturn);
-            }
-            II->setAttributes(II->getAttributes().removeAttribute(TheModule->getContext(), AttributeSet::FunctionIndex, Attribute::NoReturn));
-            assert(!II->doesNotReturn());
-          }
-
-          // Insert a normal call instruction folded in between pre- and post-invoke
-          CallInst::Create(PreInvoke, "", II);
-
-          SmallVector<Value*,16> CallArgs(II->op_begin(), II->op_end() - 3);
-          CallInst *NewCall = CallInst::Create(II->getCalledValue(),
-                                               CallArgs, "", II);
-          NewCall->takeName(II);
-          NewCall->setCallingConv(II->getCallingConv());
-          NewCall->setAttributes(II->getAttributes());
-          NewCall->setDebugLoc(II->getDebugLoc());
-          II->replaceAllUsesWith(NewCall);
-          ToErase.push_back(II);
-
-          CallInst *Post = CallInst::Create(PostInvoke, "", II);
-          Instruction *Post1 = new TruncInst(Post, i1, "", II);
-
-          // Insert a branch based on the postInvoke
-          BranchInst::Create(II->getUnwindDest(), II->getNormalDest(), Post1, II);
-        } else {
-          // This can't throw, and we don't need this invoke, just replace it with a call+branch
-          SmallVector<Value*,16> CallArgs(II->op_begin(), II->op_end() - 3);
-          CallInst *NewCall = CallInst::Create(II->getCalledValue(),
-                                               CallArgs, "", II);
-          NewCall->takeName(II);
-          NewCall->setCallingConv(II->getCallingConv());
-          NewCall->setAttributes(II->getAttributes());
-          NewCall->setDebugLoc(II->getDebugLoc());
-          II->replaceAllUsesWith(NewCall);
-          ToErase.push_back(II);
-
-          BranchInst::Create(II->getNormalDest(), II);
-
-          // Remove any PHI node entries from the exception destination.
-          II->getUnwindDest()->removePredecessor(BB);
-        }
-
-        Changed = true;
-      }
-      // scan the body of the basic block for resumes
-      for (BasicBlock::iterator Iter = BB->begin(), E = BB->end();
-           Iter != E; ) {
-        Instruction *I = Iter++;
-        if (ResumeInst *R = dyn_cast<ResumeInst>(I)) {
-          // split the input into legal values
-          Value *Input = R->getValue();
-          ExtractValueInst *Low = ExtractValueInst::Create(Input, 0, "", R);
-          ExtractValueInst *High = ExtractValueInst::Create(Input, 1, "", R);
-
-          // create a resume call
-          SmallVector<Value*,2> CallArgs;
-          CallArgs.push_back(Low);
-          CallArgs.push_back(High);
-          CallInst::Create(Resume, CallArgs, "", R);
-
-          new UnreachableInst(TheModule->getContext(), R); // add a terminator to the block
-
-          ToErase.push_back(R);
-        }
-      }
-    }
-
-    // Look for orphan landingpads, can occur in blocks with no predecesors
-    for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
-      Instruction *I = BB->getFirstNonPHI();
-      if (LandingPadInst *LP = dyn_cast<LandingPadInst>(I)) {
-        LandingPads.insert(LP);
-      }
-    }
-
-    // Handle all the landingpad for this function together, as multiple invokes may share a single lp
-    for (std::set<LandingPadInst*>::iterator I = LandingPads.begin(); I != LandingPads.end(); I++) {
-      // Replace the landingpad with a landingpad call to get the low part, and a getHigh for the high
-      LandingPadInst *LP = *I;
-      unsigned Num = LP->getNumClauses();
-      SmallVector<Value*,16> NewLPArgs;
-      NewLPArgs.push_back(LP->getPersonalityFn());
-      for (unsigned i = 0; i < Num; i++) {
-        Value *Arg = LP->getClause(i);
-        // As a temporary workaround for the lack of aggregate varargs support
-        // in the varargs lowering code, break out filter operands into their
-        // component elements.
-        if (LP->isFilter(i)) {
-          ArrayType *ATy = cast<ArrayType>(Arg->getType());
-          for (unsigned elem = 0, elemEnd = ATy->getNumElements(); elem != elemEnd; ++elem) {
-            Instruction *EE = ExtractValueInst::Create(Arg, makeArrayRef(elem), "", LP);
-            NewLPArgs.push_back(EE);
-          }
-        } else {
-          NewLPArgs.push_back(Arg);
-        }
-      }
-      NewLPArgs.push_back(LP->isCleanup() ? ConstantInt::getTrue(i1) : ConstantInt::getFalse(i1));
-      CallInst *NewLP = CallInst::Create(LandingPad, NewLPArgs, "", LP);
-
-      Instruction *High = CallInst::Create(GetHigh, "", LP);
-
-      // New recreate an aggregate for them, which will be all simplified later (simplification cannot handle landingpad, hence all this)
-      InsertValueInst *IVA = InsertValueInst::Create(UndefValue::get(LP->getType()), NewLP, 0, "", LP);
-      InsertValueInst *IVB = InsertValueInst::Create(IVA, High, 1, "", LP);
-
-      LP->replaceAllUsesWith(IVB);
-      ToErase.push_back(LP);
-    }
-
-    // erase everything we no longer need in this function
-    for (unsigned i = 0; i < ToErase.size(); i++) ToErase[i]->eraseFromParent();
-  }
-
-  return Changed;
-}
-
-ModulePass *llvm::createLowerEmExceptionsPass() {
-  return new LowerEmExceptions();
-}
-