Reland "[IR] Make AttributeSetNode public, avoid temporary AttributeList copies"

This re-lands r299875.

I introduced a bug in Clang code responsible for replacing K&R, no
prototype declarations with a real function definition with a prototype.
The bug was here:

       // Collect any return attributes from the call.
  -    if (oldAttrs.hasAttributes(llvm::AttributeList::ReturnIndex))
  -      newAttrs.push_back(llvm::AttributeList::get(newFn->getContext(),
  -                                                  oldAttrs.getRetAttributes()));
  +    newAttrs.push_back(oldAttrs.getRetAttributes());

Previously getRetAttributes() carried AttributeList::ReturnIndex in its
AttributeList. Now that we return the AttributeSetNode* directly, it no
longer carries that index, and we call this overload with a single node:
  AttributeList::get(LLVMContext&, ArrayRef<AttributeSetNode*>)

That aborted with an assertion on x86_32 targets. I added an explicit
triple to the test and added CHECKs to help find issues like this in the
future sooner.

llvm-svn: 299899

1 files changed, 9 insertions, 6 deletions

diff --git a/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp b/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
index e87edc82e65..7223370a717 100644
--- a/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
+++ b/llvm/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
@@ -1392,7 +1392,6 @@ makeStatepointExplicitImpl(const CallSite CS, /* to replace */
 
   // Create the statepoint given all the arguments
   Instruction *Token = nullptr;
-  AttributeList ReturnAttrs;
   if (CS.isCall()) {
     CallInst *ToReplace = cast<CallInst>(CS.getInstruction());
     CallInst *Call = Builder.CreateGCStatepointCall(
@@ -1407,8 +1406,9 @@ makeStatepointExplicitImpl(const CallSite CS, /* to replace */
     AttributeList NewAttrs = legalizeCallAttributes(ToReplace->getAttributes());
     // In case if we can handle this set of attributes - set up function attrs
     // directly on statepoint and return attrs later for gc_result intrinsic.
-    Call->setAttributes(NewAttrs.getFnAttributes());
-    ReturnAttrs = NewAttrs.getRetAttributes();
+    Call->setAttributes(AttributeList::get(Call->getContext(),
+                                           AttributeList::FunctionIndex,
+                                           NewAttrs.getFnAttributes()));
 
     Token = Call;
 
@@ -1435,8 +1435,9 @@ makeStatepointExplicitImpl(const CallSite CS, /* to replace */
     AttributeList NewAttrs = legalizeCallAttributes(ToReplace->getAttributes());
     // In case if we can handle this set of attributes - set up function attrs
     // directly on statepoint and return attrs later for gc_result intrinsic.
-    Invoke->setAttributes(NewAttrs.getFnAttributes());
-    ReturnAttrs = NewAttrs.getRetAttributes();
+    Invoke->setAttributes(AttributeList::get(Invoke->getContext(),
+                                             AttributeList::FunctionIndex,
+                                             NewAttrs.getFnAttributes()));
 
     Token = Invoke;
 
@@ -1482,7 +1483,9 @@ makeStatepointExplicitImpl(const CallSite CS, /* to replace */
       StringRef Name =
           CS.getInstruction()->hasName() ? CS.getInstruction()->getName() : "";
       CallInst *GCResult = Builder.CreateGCResult(Token, CS.getType(), Name);
-      GCResult->setAttributes(CS.getAttributes().getRetAttributes());
+      GCResult->setAttributes(
+          AttributeList::get(GCResult->getContext(), AttributeList::ReturnIndex,
+                             CS.getAttributes().getRetAttributes()));
 
       // We cannot RAUW or delete CS.getInstruction() because it could be in the
       // live set of some other safepoint, in which case that safepoint's