1 files changed, 34 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/IPO/Inliner.cpp b/llvm/lib/Transforms/IPO/Inliner.cpp
index 6335d05e2d9..54505017136 100644
--- a/llvm/lib/Transforms/IPO/Inliner.cpp
+++ b/llvm/lib/Transforms/IPO/Inliner.cpp
@@ -86,6 +86,39 @@ void Inliner::getAnalysisUsage(AnalysisUsage &AU) const {
 typedef DenseMap<ArrayType*, std::vector<AllocaInst*> >
 InlinedArrayAllocasTy;
 
+/// \brief If the inlined function had a higher stack protection level than the
+/// calling function, then bump up the caller's stack protection level.
+static void AdjustCallerSSPLevel(Function *Caller, Function *Callee) {
+  // If upgrading the SSP attribute, clear out the old SSP Attributes first.
+  // Having multiple SSP attributes doesn't actually hurt, but it adds useless
+  // clutter to the IR.
+  AttrBuilder B;
+  B.addAttribute(Attribute::StackProtect)
+    .addAttribute(Attribute::StackProtectStrong)
+    .addAttribute(Attribute::StackProtectReq);
+  AttributeSet OldSSPAttr = AttributeSet::get(Caller->getContext(),
+                                              AttributeSet::FunctionIndex,
+                                              B);
+
+  if (Callee->hasFnAttribute(Attribute::SafeStack)) {
+    Caller->removeAttributes(AttributeSet::FunctionIndex, OldSSPAttr);
+    Caller->addFnAttr(Attribute::SafeStack);
+  } else if (Callee->hasFnAttribute(Attribute::StackProtectReq) &&
+             !Caller->hasFnAttribute(Attribute::SafeStack)) {
+    Caller->removeAttributes(AttributeSet::FunctionIndex, OldSSPAttr);
+    Caller->addFnAttr(Attribute::StackProtectReq);
+  } else if (Callee->hasFnAttribute(Attribute::StackProtectStrong) &&
+             !Caller->hasFnAttribute(Attribute::SafeStack) &&
+             !Caller->hasFnAttribute(Attribute::StackProtectReq)) {
+    Caller->removeAttributes(AttributeSet::FunctionIndex, OldSSPAttr);
+    Caller->addFnAttr(Attribute::StackProtectStrong);
+  } else if (Callee->hasFnAttribute(Attribute::StackProtect) &&
+             !Caller->hasFnAttribute(Attribute::SafeStack) &&
+             !Caller->hasFnAttribute(Attribute::StackProtectReq) &&
+             !Caller->hasFnAttribute(Attribute::StackProtectStrong))
+    Caller->addFnAttr(Attribute::StackProtect);
+}
+
 /// If it is possible to inline the specified call site,
 /// do so and update the CallGraph for this operation.
 ///
@@ -113,7 +146,7 @@ static bool InlineCallIfPossible(Pass &P, CallSite CS, InlineFunctionInfo &IFI,
   if (!InlineFunction(CS, IFI, &AAR, InsertLifetime))
     return false;
 
-  AttributeFuncs::mergeAttributesForInlining(*Caller, *Callee);
+  AdjustCallerSSPLevel(Caller, Callee);
 
   // Look at all of the allocas that we inlined through this call site.  If we
   // have already inlined other allocas through other calls into this function,