Move the personality function from LandingPadInst to Function

The personality routine currently lives in the LandingPadInst.

This isn't desirable because:
- All LandingPadInsts in the same function must have the same
  personality routine.  This means that each LandingPadInst beyond the
  first has an operand which produces no additional information.

- There is ongoing work to introduce EH IR constructs other than
  LandingPadInst.  Moving the personality routine off of any one
  particular Instruction and onto the parent function seems a lot better
  than have N different places a personality function can sneak onto an
  exceptional function.

Differential Revision: http://reviews.llvm.org/D10429

llvm-svn: 239940

6 files changed, 67 insertions, 50 deletions

diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index 05f7e08555f..23393ccd5c0 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -109,6 +109,10 @@ static OrderMap orderModule(const Module *M) {
       if (!isa<GlobalValue>(F.getPrologueData()))
         orderValue(F.getPrologueData(), OM);
 
+    if (F.hasPersonalityFn())
+      if (!isa<GlobalValue>(F.getPersonalityFn()))
+        orderValue(F.getPersonalityFn(), OM);
+
     orderValue(&F, OM);
 
     if (F.isDeclaration())
@@ -2540,6 +2544,10 @@ void AssemblyWriter::printFunction(const Function *F) {
     Out << " prologue ";
     writeOperand(F->getPrologueData(), true);
   }
+  if (F->hasPersonalityFn()) {
+    Out << " personality ";
+    writeOperand(F->getPersonalityFn(), /*PrintType=*/true);
+  }
 
   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
   F->getAllMetadata(MDs);
@@ -2782,8 +2790,8 @@ void AssemblyWriter::printInstruction(const Instruction &I) {
   } else if (const LandingPadInst *LPI = dyn_cast<LandingPadInst>(&I)) {
     Out << ' ';
     TypePrinter.print(I.getType(), Out);
-    Out << " personality ";
-    writeOperand(I.getOperand(0), true); Out << '\n';
+    if (LPI->isCleanup() || LPI->getNumClauses() != 0)
+      Out << '\n';
 
     if (LPI->isCleanup())
       Out << "          cleanup";
diff --git a/llvm/lib/IR/Core.cpp b/llvm/lib/IR/Core.cpp
index d476434542e..23e923d4112 100644
--- a/llvm/lib/IR/Core.cpp
+++ b/llvm/lib/IR/Core.cpp
@@ -2249,11 +2249,8 @@ LLVMValueRef LLVMBuildInvoke(LLVMBuilderRef B, LLVMValueRef Fn,
 }
 
 LLVMValueRef LLVMBuildLandingPad(LLVMBuilderRef B, LLVMTypeRef Ty,
-                                 LLVMValueRef PersFn, unsigned NumClauses,
-                                 const char *Name) {
-  return wrap(unwrap(B)->CreateLandingPad(unwrap(Ty),
-                                          cast<Function>(unwrap(PersFn)),
-                                          NumClauses, Name));
+                                 unsigned NumClauses, const char *Name) {
+  return wrap(unwrap(B)->CreateLandingPad(unwrap(Ty), NumClauses, Name));
 }
 
 LLVMValueRef LLVMBuildResume(LLVMBuilderRef B, LLVMValueRef Exn) {
diff --git a/llvm/lib/IR/Function.cpp b/llvm/lib/IR/Function.cpp
index 2b439bb46bf..bc57dee0af0 100644
--- a/llvm/lib/IR/Function.cpp
+++ b/llvm/lib/IR/Function.cpp
@@ -248,8 +248,8 @@ void Function::eraseFromParent() {
 
 Function::Function(FunctionType *Ty, LinkageTypes Linkage, const Twine &name,
                    Module *ParentModule)
-    : GlobalObject(PointerType::getUnqual(Ty), Value::FunctionVal, nullptr, 0,
-                   Linkage, name),
+    : GlobalObject(PointerType::getUnqual(Ty), Value::FunctionVal,
+                   OperandTraits<Function>::op_begin(this), 0, Linkage, name),
       Ty(Ty) {
   assert(FunctionType::isValidReturnType(getReturnType()) &&
          "invalid return type");
@@ -279,6 +279,9 @@ Function::~Function() {
 
   // Remove the function from the on-the-side GC table.
   clearGC();
+
+  // FIXME: needed by operator delete
+  setFunctionNumOperands(1);
 }
 
 void Function::BuildLazyArguments() const {
@@ -331,6 +334,8 @@ void Function::dropAllReferences() {
 
   // Metadata is stored in a side-table.
   clearMetadata();
+
+  setPersonalityFn(nullptr);
 }
 
 void Function::addAttribute(unsigned i, Attribute::AttrKind attr) {
@@ -426,6 +431,10 @@ void Function::copyAttributesFrom(const GlobalValue *Src) {
     setPrologueData(SrcF->getPrologueData());
   else
     setPrologueData(nullptr);
+  if (SrcF->hasPersonalityFn())
+    setPersonalityFn(SrcF->getPersonalityFn());
+  else
+    setPersonalityFn(nullptr);
 }
 
 /// \brief This does the actual lookup of an intrinsic ID which
@@ -976,3 +985,22 @@ Optional<uint64_t> Function::getEntryCount() const {
       }
   return None;
 }
+
+void Function::setPersonalityFn(Constant *C) {
+  if (!C) {
+    if (hasPersonalityFn()) {
+      // Note, the num operands is used to compute the offset of the operand, so
+      // the order here matters.  Clearing the operand then clearing the num
+      // operands ensures we have the correct offset to the operand.
+      Op<0>().set(nullptr);
+      setFunctionNumOperands(0);
+    }
+  } else {
+    // Note, the num operands is used to compute the offset of the operand, so
+    // the order here matters.  We need to set num operands to 1 first so that
+    // we get the correct offset to the first operand when we set it.
+    if (!hasPersonalityFn())
+      setFunctionNumOperands(1);
+    Op<0>().set(C);
+  }
+}
diff --git a/llvm/lib/IR/Instructions.cpp b/llvm/lib/IR/Instructions.cpp
index 0e2fe391aa6..d45b5110536 100644
--- a/llvm/lib/IR/Instructions.cpp
+++ b/llvm/lib/IR/Instructions.cpp
@@ -153,18 +153,16 @@ Value *PHINode::hasConstantValue() const {
 //                       LandingPadInst Implementation
 //===----------------------------------------------------------------------===//
 
-LandingPadInst::LandingPadInst(Type *RetTy, Value *PersonalityFn,
-                               unsigned NumReservedValues, const Twine &NameStr,
-                               Instruction *InsertBefore)
-  : Instruction(RetTy, Instruction::LandingPad, nullptr, 0, InsertBefore) {
-  init(PersonalityFn, 1 + NumReservedValues, NameStr);
+LandingPadInst::LandingPadInst(Type *RetTy, unsigned NumReservedValues,
+                               const Twine &NameStr, Instruction *InsertBefore)
+    : Instruction(RetTy, Instruction::LandingPad, nullptr, 0, InsertBefore) {
+  init(NumReservedValues, NameStr);
 }
 
-LandingPadInst::LandingPadInst(Type *RetTy, Value *PersonalityFn,
-                               unsigned NumReservedValues, const Twine &NameStr,
-                               BasicBlock *InsertAtEnd)
-  : Instruction(RetTy, Instruction::LandingPad, nullptr, 0, InsertAtEnd) {
-  init(PersonalityFn, 1 + NumReservedValues, NameStr);
+LandingPadInst::LandingPadInst(Type *RetTy, unsigned NumReservedValues,
+                               const Twine &NameStr, BasicBlock *InsertAtEnd)
+    : Instruction(RetTy, Instruction::LandingPad, nullptr, 0, InsertAtEnd) {
+  init(NumReservedValues, NameStr);
 }
 
 LandingPadInst::LandingPadInst(const LandingPadInst &LP)
@@ -180,28 +178,22 @@ LandingPadInst::LandingPadInst(const LandingPadInst &LP)
   setCleanup(LP.isCleanup());
 }
 
-LandingPadInst *LandingPadInst::Create(Type *RetTy, Value *PersonalityFn,
-                                       unsigned NumReservedClauses,
+LandingPadInst *LandingPadInst::Create(Type *RetTy, unsigned NumReservedClauses,
                                        const Twine &NameStr,
                                        Instruction *InsertBefore) {
-  return new LandingPadInst(RetTy, PersonalityFn, NumReservedClauses, NameStr,
-                            InsertBefore);
+  return new LandingPadInst(RetTy, NumReservedClauses, NameStr, InsertBefore);
 }
 
-LandingPadInst *LandingPadInst::Create(Type *RetTy, Value *PersonalityFn,
-                                       unsigned NumReservedClauses,
+LandingPadInst *LandingPadInst::Create(Type *RetTy, unsigned NumReservedClauses,
                                        const Twine &NameStr,
                                        BasicBlock *InsertAtEnd) {
-  return new LandingPadInst(RetTy, PersonalityFn, NumReservedClauses, NameStr,
-                            InsertAtEnd);
+  return new LandingPadInst(RetTy, NumReservedClauses, NameStr, InsertAtEnd);
 }
 
-void LandingPadInst::init(Value *PersFn, unsigned NumReservedValues,
-                          const Twine &NameStr) {
+void LandingPadInst::init(unsigned NumReservedValues, const Twine &NameStr) {
   ReservedSpace = NumReservedValues;
-  setNumHungOffUseOperands(1);
+  setNumHungOffUseOperands(0);
   allocHungoffUses(ReservedSpace);
-  Op<0>() = PersFn;
   setName(NameStr);
   setCleanup(false);
 }
@@ -211,7 +203,7 @@ void LandingPadInst::init(Value *PersFn, unsigned NumReservedValues,
 void LandingPadInst::growOperands(unsigned Size) {
   unsigned e = getNumOperands();
   if (ReservedSpace >= e + Size) return;
-  ReservedSpace = (e + Size / 2) * 2;
+  ReservedSpace = (std::max(e, 1U) + Size / 2) * 2;
   growHungoffUses(ReservedSpace);
 }
 
diff --git a/llvm/lib/IR/TypeFinder.cpp b/llvm/lib/IR/TypeFinder.cpp
index 1d2b808d650..7accc5bef53 100644
--- a/llvm/lib/IR/TypeFinder.cpp
+++ b/llvm/lib/IR/TypeFinder.cpp
@@ -50,6 +50,9 @@ void TypeFinder::run(const Module &M, bool onlyNamed) {
     if (FI->hasPrologueData())
       incorporateValue(FI->getPrologueData());
 
+    if (FI->hasPersonalityFn())
+      incorporateValue(FI->getPersonalityFn());
+
     // First incorporate the arguments.
     for (Function::const_arg_iterator AI = FI->arg_begin(),
            AE = FI->arg_end(); AI != AE; ++AI)
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 13b451a06b2..51d1cdbb117 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -181,11 +181,6 @@ class Verifier : public InstVisitor<Verifier>, VerifierSupport {
   /// \brief Track unresolved string-based type references.
   SmallDenseMap<const MDString *, const MDNode *, 32> UnresolvedTypeRefs;
 
-  /// \brief The personality function referenced by the LandingPadInsts.
-  /// All LandingPadInsts within the same function must use the same
-  /// personality function.
-  const Value *PersonalityFn;
-
   /// \brief Whether we've seen a call to @llvm.frameescape in this function
   /// already.
   bool SawFrameEscape;
@@ -196,8 +191,7 @@ class Verifier : public InstVisitor<Verifier>, VerifierSupport {
 
 public:
   explicit Verifier(raw_ostream &OS)
-      : VerifierSupport(OS), Context(nullptr), PersonalityFn(nullptr),
-        SawFrameEscape(false) {}
+      : VerifierSupport(OS), Context(nullptr), SawFrameEscape(false) {}
 
   bool verify(const Function &F) {
     M = F.getParent();
@@ -231,7 +225,6 @@ public:
     // FIXME: We strip const here because the inst visitor strips const.
     visit(const_cast<Function &>(F));
     InstsInThisBlock.clear();
-    PersonalityFn = nullptr;
     SawFrameEscape = false;
 
     return !Broken;
@@ -1757,6 +1750,8 @@ void Verifier::visitFunction(const Function &F) {
            "invalid linkage type for function declaration", &F);
     Assert(MDs.empty(), "function without a body cannot have metadata", &F,
            MDs.empty() ? nullptr : MDs.front().second);
+    Assert(!F.hasPersonalityFn(),
+           "Function declaration shouldn't have a personality routine", &F);
   } else {
     // Verify that this function (which has a body) is not named "llvm.*".  It
     // is not legal to define intrinsics.
@@ -2795,22 +2790,16 @@ void Verifier::visitLandingPadInst(LandingPadInst &LPI) {
            &LPI);
   }
 
+  Function *F = LPI.getParent()->getParent();
+  Assert(F->hasPersonalityFn(),
+         "LandingPadInst needs to be in a function with a personality.", &LPI);
+
   // The landingpad instruction must be the first non-PHI instruction in the
   // block.
   Assert(LPI.getParent()->getLandingPadInst() == &LPI,
          "LandingPadInst not the first non-PHI instruction in the block.",
          &LPI);
 
-  // The personality functions for all landingpad instructions within the same
-  // function should match.
-  if (PersonalityFn)
-    Assert(LPI.getPersonalityFn() == PersonalityFn,
-           "Personality function doesn't match others in function", &LPI);
-  PersonalityFn = LPI.getPersonalityFn();
-
-  // All operands must be constants.
-  Assert(isa<Constant>(PersonalityFn), "Personality function is not constant!",
-         &LPI);
   for (unsigned i = 0, e = LPI.getNumClauses(); i < e; ++i) {
     Constant *Clause = LPI.getClause(i);
     if (LPI.isCatch(i)) {