1 files changed, 17 insertions, 23 deletions

diff --git a/lib/CodeGen/DwarfEHPrepare.cpp b/lib/CodeGen/DwarfEHPrepare.cpp
index 75b74d9..7b47a48 100644
--- a/lib/CodeGen/DwarfEHPrepare.cpp
+++ b/lib/CodeGen/DwarfEHPrepare.cpp
@@ -14,18 +14,12 @@
 
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/ADT/Statistic.h"
-#include "llvm/IR/CallSite.h"
-#include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Module.h"
-#include "llvm/MC/MCAsmInfo.h"
 #include "llvm/Pass.h"
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetSubtargetInfo.h"
-#include "llvm/Transforms/Utils/BasicBlockUtils.h"
-#include "llvm/Transforms/Utils/SSAUpdater.h"
 using namespace llvm;
 
 #define DEBUG_TYPE "dwarfehprepare"
@@ -44,10 +38,13 @@ namespace {
 
   public:
     static char ID; // Pass identification, replacement for typeid.
+
+    // INITIALIZE_TM_PASS requires a default constructor, but it isn't used in
+    // practice.
+    DwarfEHPrepare() : FunctionPass(ID), TM(nullptr), RewindFunction(nullptr) {}
+
     DwarfEHPrepare(const TargetMachine *TM)
-        : FunctionPass(ID), TM(TM), RewindFunction(nullptr) {
-      initializeDominatorTreeWrapperPassPass(*PassRegistry::getPassRegistry());
-    }
+        : FunctionPass(ID), TM(TM), RewindFunction(nullptr) {}
 
     bool runOnFunction(Function &Fn) override;
 
@@ -56,8 +53,6 @@ namespace {
       return false;
     }
 
-    void getAnalysisUsage(AnalysisUsage &AU) const override { }
-
     const char *getPassName() const override {
       return "Exception handling preparation";
     }
@@ -65,6 +60,8 @@ namespace {
 } // end anonymous namespace
 
 char DwarfEHPrepare::ID = 0;
+INITIALIZE_TM_PASS(DwarfEHPrepare, "dwarfehprepare", "Prepare DWARF exceptions",
+                   false, false)
 
 FunctionPass *llvm::createDwarfEHPass(const TargetMachine *TM) {
   return new DwarfEHPrepare(TM);
@@ -99,11 +96,11 @@ Value *DwarfEHPrepare::GetExceptionObject(ResumeInst *RI) {
   RI->eraseFromParent();
 
   if (EraseIVIs) {
-    if (SelIVI->getNumUses() == 0)
+    if (SelIVI->use_empty())
       SelIVI->eraseFromParent();
-    if (ExcIVI->getNumUses() == 0)
+    if (ExcIVI->use_empty())
       ExcIVI->eraseFromParent();
-    if (SelLoad && SelLoad->getNumUses() == 0)
+    if (SelLoad && SelLoad->use_empty())
       SelLoad->eraseFromParent();
   }
 
@@ -114,9 +111,8 @@ Value *DwarfEHPrepare::GetExceptionObject(ResumeInst *RI) {
 /// into calls to the appropriate _Unwind_Resume function.
 bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
   SmallVector<ResumeInst*, 16> Resumes;
-  for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) {
-    TerminatorInst *TI = I->getTerminator();
-    if (ResumeInst *RI = dyn_cast<ResumeInst>(TI))
+  for (BasicBlock &BB : Fn) {
+    if (auto *RI = dyn_cast<ResumeInst>(BB.getTerminator()))
       Resumes.push_back(RI);
   }
 
@@ -124,9 +120,9 @@ bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
     return false;
 
   // Find the rewind function if we didn't already.
-  const TargetLowering *TLI = TM->getSubtargetImpl()->getTargetLowering();
+  const TargetLowering *TLI = TM->getSubtargetImpl(Fn)->getTargetLowering();
+  LLVMContext &Ctx = Fn.getContext();
   if (!RewindFunction) {
-    LLVMContext &Ctx = Resumes[0]->getContext();
     FunctionType *FTy = FunctionType::get(Type::getVoidTy(Ctx),
                                           Type::getInt8PtrTy(Ctx), false);
     const char *RewindName = TLI->getLibcallName(RTLIB::UNWIND_RESUME);
@@ -134,7 +130,6 @@ bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
   }
 
   // Create the basic block where the _Unwind_Resume call will live.
-  LLVMContext &Ctx = Fn.getContext();
   unsigned ResumesSize = Resumes.size();
 
   if (ResumesSize == 1) {
@@ -159,9 +154,7 @@ bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
 
   // Extract the exception object from the ResumeInst and add it to the PHI node
   // that feeds the _Unwind_Resume call.
-  for (SmallVectorImpl<ResumeInst*>::iterator
-         I = Resumes.begin(), E = Resumes.end(); I != E; ++I) {
-    ResumeInst *RI = *I;
+  for (ResumeInst *RI : Resumes) {
     BasicBlock *Parent = RI->getParent();
     BranchInst::Create(UnwindBB, Parent);
 
@@ -181,6 +174,7 @@ bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
 }
 
 bool DwarfEHPrepare::runOnFunction(Function &Fn) {
+  assert(TM && "DWARF EH preparation requires a target machine");
   bool Changed = InsertUnwindResumeCalls(Fn);
   return Changed;
 }