1 files changed, 29 insertions, 22 deletions

diff --git a/lib/Transforms/IPO/PruneEH.cpp b/lib/Transforms/IPO/PruneEH.cpp
index 22a95fa03f7c5..2aa3fa55cefdc 100644
--- a/lib/Transforms/IPO/PruneEH.cpp
+++ b/lib/Transforms/IPO/PruneEH.cpp
@@ -16,7 +16,6 @@
 
 #include "llvm/Transforms/IPO.h"
 #include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Analysis/CallGraph.h"
@@ -48,10 +47,10 @@ namespace {
     // runOnSCC - Analyze the SCC, performing the transformation if possible.
     bool runOnSCC(CallGraphSCC &SCC) override;
 
-    bool SimplifyFunction(Function *F);
-    void DeleteBasicBlock(BasicBlock *BB);
   };
 }
+static bool SimplifyFunction(Function *F, CallGraph &CG);
+static void DeleteBasicBlock(BasicBlock *BB, CallGraph &CG);
 
 char PruneEH::ID = 0;
 INITIALIZE_PASS_BEGIN(PruneEH, "prune-eh",
@@ -62,22 +61,20 @@ INITIALIZE_PASS_END(PruneEH, "prune-eh",
 
 Pass *llvm::createPruneEHPass() { return new PruneEH(); }
 
-
-bool PruneEH::runOnSCC(CallGraphSCC &SCC) {
+static bool runImpl(CallGraphSCC &SCC, CallGraph &CG) {
   SmallPtrSet<CallGraphNode *, 8> SCCNodes;
-  CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
   bool MadeChange = false;
 
   // Fill SCCNodes with the elements of the SCC.  Used for quickly
   // looking up whether a given CallGraphNode is in this SCC.
-  for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I)
-    SCCNodes.insert(*I);
+  for (CallGraphNode *I : SCC)
+    SCCNodes.insert(I);
 
   // First pass, scan all of the functions in the SCC, simplifying them
   // according to what we know.
-  for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I)
-    if (Function *F = (*I)->getFunction())
-      MadeChange |= SimplifyFunction(F);
+  for (CallGraphNode *I : SCC)
+    if (Function *F = I->getFunction())
+      MadeChange |= SimplifyFunction(F, CG);
 
   // Next, check to see if any callees might throw or if there are any external
   // functions in this SCC: if so, we cannot prune any functions in this SCC.
@@ -93,7 +90,10 @@ bool PruneEH::runOnSCC(CallGraphSCC &SCC) {
     if (!F) {
       SCCMightUnwind = true;
       SCCMightReturn = true;
-    } else if (F->isDeclaration() || F->mayBeOverridden()) {
+    } else if (F->isDeclaration() || F->isInterposable()) {
+      // Note: isInterposable (as opposed to hasExactDefinition) is fine above,
+      // since we're not inferring new attributes here, but only using existing,
+      // assumed to be correct, function attributes.
       SCCMightUnwind |= !F->doesNotThrow();
       SCCMightReturn |= !F->doesNotReturn();
     } else {
@@ -153,8 +153,8 @@ bool PruneEH::runOnSCC(CallGraphSCC &SCC) {
 
   // If the SCC doesn't unwind or doesn't throw, note this fact.
   if (!SCCMightUnwind || !SCCMightReturn)
-    for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
-      Function *F = (*I)->getFunction();
+    for (CallGraphNode *I : SCC) {
+      Function *F = I->getFunction();
 
       if (!SCCMightUnwind && !F->hasFnAttribute(Attribute::NoUnwind)) {
         F->addFnAttr(Attribute::NoUnwind);
@@ -167,22 +167,30 @@ bool PruneEH::runOnSCC(CallGraphSCC &SCC) {
       }
     }
 
-  for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) {
+  for (CallGraphNode *I : SCC) {
     // Convert any invoke instructions to non-throwing functions in this node
     // into call instructions with a branch.  This makes the exception blocks
     // dead.
-    if (Function *F = (*I)->getFunction())
-      MadeChange |= SimplifyFunction(F);
+    if (Function *F = I->getFunction())
+      MadeChange |= SimplifyFunction(F, CG);
   }
 
   return MadeChange;
 }
 
 
+bool PruneEH::runOnSCC(CallGraphSCC &SCC) {
+  if (skipSCC(SCC))
+    return false;
+  CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
+  return runImpl(SCC, CG);
+}
+
+
 // SimplifyFunction - Given information about callees, simplify the specified
 // function if we have invokes to non-unwinding functions or code after calls to
 // no-return functions.
-bool PruneEH::SimplifyFunction(Function *F) {
+static bool SimplifyFunction(Function *F, CallGraph &CG) {
   bool MadeChange = false;
   for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
     if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator()))
@@ -192,7 +200,7 @@ bool PruneEH::SimplifyFunction(Function *F) {
 
         // If the unwind block is now dead, nuke it.
         if (pred_empty(UnwindBlock))
-          DeleteBasicBlock(UnwindBlock);  // Delete the new BB.
+          DeleteBasicBlock(UnwindBlock, CG);  // Delete the new BB.
 
         ++NumRemoved;
         MadeChange = true;
@@ -211,7 +219,7 @@ bool PruneEH::SimplifyFunction(Function *F) {
           BB->getInstList().pop_back();
           new UnreachableInst(BB->getContext(), &*BB);
 
-          DeleteBasicBlock(New);  // Delete the new BB.
+          DeleteBasicBlock(New, CG);  // Delete the new BB.
           MadeChange = true;
           ++NumUnreach;
           break;
@@ -224,9 +232,8 @@ bool PruneEH::SimplifyFunction(Function *F) {
 /// DeleteBasicBlock - remove the specified basic block from the program,
 /// updating the callgraph to reflect any now-obsolete edges due to calls that
 /// exist in the BB.
-void PruneEH::DeleteBasicBlock(BasicBlock *BB) {
+static void DeleteBasicBlock(BasicBlock *BB, CallGraph &CG) {
   assert(pred_empty(BB) && "BB is not dead!");
-  CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
 
   Instruction *TokenInst = nullptr;