diff --git a/lib/Transforms/ObjCARC/ObjCARCOpts.cpp b/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
index 27bc2bb5312..d13baf3db86 100644
--- a/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
+++ b/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
@@ -701,6 +701,151 @@ void BBState::MergeSucc(const BBState &Other) {
MI->second.Merge(PtrState(), /*TopDown=*/false);
}
+// Only enable ARC Annotations if we are building a debug version of
+// libObjCARCOpts.
+#ifndef NDEBUG
+#define ARC_ANNOTATIONS
+#endif
+
+// Define some macros along the lines of DEBUG and some helper functions to make
+// it cleaner to create annotations in the source code and to no-op when not
+// building in debug mode.
+#ifdef ARC_ANNOTATIONS
+
+#include "llvm/Support/CommandLine.h"
+
+/// Enable/disable ARC sequence annotations.
+static cl::opt<bool>
+EnableARCAnnotations("enable-objc-arc-annotations", cl::init(false));
+
+/// This function appends a unique ARCAnnotationProvenanceSourceMDKind id to an
+/// instruction so that we can track backwards when post processing via the llvm
+/// arc annotation processor tool. If the function is an
+static MDString *AppendMDNodeToSourcePtr(unsigned NodeId,
+ Value *Ptr) {
+ MDString *Hash = 0;
+
+ // If pointer is a result of an instruction and it does not have a source
+ // MDNode it, attach a new MDNode onto it. If pointer is a result of
+ // an instruction and does have a source MDNode attached to it, return a
+ // reference to said Node. Otherwise just return 0.
+ if (Instruction *Inst = dyn_cast<Instruction>(Ptr)) {
+ MDNode *Node;
+ if (!(Node = Inst->getMetadata(NodeId))) {
+ // We do not have any node. Generate and attatch the hash MDString to the
+ // instruction.
+
+ // We just use an MDString to ensure that this metadata gets written out
+ // of line at the module level and to provide a very simple format
+ // encoding the information herein. Both of these makes it simpler to
+ // parse the annotations by a simple external program.
+ std::string Str;
+ raw_string_ostream os(Str);
+ os << "(" << Inst->getParent()->getParent()->getName() << ",%"
+ << Inst->getName() << ")";
+
+ Hash = MDString::get(Inst->getContext(), os.str());
+ Inst->setMetadata(NodeId, MDNode::get(Inst->getContext(),Hash));
+ } else {
+ // We have a node. Grab its hash and return it.
+ assert(Node->getNumOperands() == 1 &&
+ "An ARCAnnotationProvenanceSourceMDKind can only have 1 operand.");
+ Hash = cast<MDString>(Node->getOperand(0));
+ }
+ } else if (Argument *Arg = dyn_cast<Argument>(Ptr)) {
+ std::string str;
+ raw_string_ostream os(str);
+ os << "(" << Arg->getParent()->getName() << ",%" << Arg->getName()
+ << ")";
+ Hash = MDString::get(Arg->getContext(), os.str());
+ }
+
+ return Hash;
+}
+
+/// Helper function to change a Sequence into a String object using our overload
+/// for raw_ostream so we only have printing code in one location.
+static MDString *SequenceToMDString(LLVMContext &Context,
+ Sequence A) {
+ std::string str;
+ raw_string_ostream os(str);
+ os << A;
+ return MDString::get(Context, os.str());
+}
+
+/// A simple function to generate a MDNode which describes the change in state
+/// for Value *Ptr caused by Instruction *Inst.
+static void AppendMDNodeToInstForPtr(unsigned NodeId,
+ Instruction *Inst,
+ Value *Ptr,
+ MDString *PtrSourceMDNodeID,
+ Sequence OldSeq,
+ Sequence NewSeq) {
+ MDNode *Node = 0;
+ Value *tmp[3] = {PtrSourceMDNodeID,
+ SequenceToMDString(Inst->getContext(),
+ OldSeq),
+ SequenceToMDString(Inst->getContext(),
+ NewSeq)};
+ Node = MDNode::get(Inst->getContext(),
+ ArrayRef<Value*>(tmp, 3));
+
+ Inst->setMetadata(NodeId, Node);
+}
+
+/// Adds a source annotation to pointer and a state change annotation to Inst
+/// referencing the source annotation and the old/new state of pointer.
+static void GenerateARCAnnotation(unsigned InstMDId,
+ unsigned PtrMDId,
+ Instruction *Inst,
+ Value *Ptr,
+ Sequence OldSeq,
+ Sequence NewSeq) {
+ if (EnableARCAnnotations) {
+ // First generate the source annotation on our pointer. This will return an
+ // MDString* if Ptr actually comes from an instruction implying we can put
+ // in a source annotation. If AppendMDNodeToSourcePtr returns 0 (i.e. NULL),
+ // then we know that our pointer is from an Argument so we put a reference
+ // to the argument number.
+ //
+ // The point of this is to make it easy for the
+ // llvm-arc-annotation-processor tool to cross reference where the source
+ // pointer is in the LLVM IR since the LLVM IR parser does not submit such
+ // information via debug info for backends to use (since why would anyone
+ // need such a thing from LLVM IR besides in non standard cases
+ // [i.e. this]).
+ MDString *SourcePtrMDNode =
+ AppendMDNodeToSourcePtr(PtrMDId, Ptr);
+ AppendMDNodeToInstForPtr(InstMDId, Inst, Ptr, SourcePtrMDNode, OldSeq,
+ NewSeq);
+ }
+}
+
+// The actual interface for accessing the above functionality is defined via
+// some simple macros which are defined below. We do this so that the user does
+// not need to pass in what metadata id is needed resulting in cleaner code and
+// additionally since it provides an easy way to conditionally no-op all
+// annotation support in a non-debug build.
+
+/// Use this macro to annotate a sequence state change when processing
+/// instructions bottom up,
+#define ANNOTATE_BOTTOMUP(inst, ptr, old, new) \
+ GenerateARCAnnotation(ARCAnnotationBottomUpMDKind, \
+ ARCAnnotationProvenanceSourceMDKind, (inst), \
+ const_cast<Value*>(ptr), (old), (new))
+/// Use this macro to annotate a sequence state change when processing
+/// instructions top down.
+#define ANNOTATE_TOPDOWN(inst, ptr, old, new) \
+ GenerateARCAnnotation(ARCAnnotationTopDownMDKind, \
+ ARCAnnotationProvenanceSourceMDKind, (inst), \
+ const_cast<Value*>(ptr), (old), (new))
+
+#else // !ARC_ANNOTATION
+// If annotations are off, noop.
+#define ANNOTATE_BOTTOMUP(inst, ptr, old, new)
+#define ANNOTATE_TOPDOWN(inst, ptr, old, new)
+#endif // !ARC_ANNOTATION
+
namespace {
/// \brief The main ARC optimization pass.
class ObjCARCOpt : public FunctionPass {
@@ -741,6 +886,15 @@ namespace {
/// The Metadata Kind for clang.arc.no_objc_arc_exceptions metadata.
unsigned NoObjCARCExceptionsMDKind;
+#ifdef ARC_ANNOTATIONS
+ /// The Metadata Kind for llvm.arc.annotation.bottomup metadata.
+ unsigned ARCAnnotationBottomUpMDKind;
+ /// The Metadata Kind for llvm.arc.annotation.topdown metadata.
+ unsigned ARCAnnotationTopDownMDKind;
+ /// The Metadata Kind for llvm.arc.annotation.provenancesource metadata.
+ unsigned ARCAnnotationProvenanceSourceMDKind;
+#endif // ARC_ANNOATIONS
+
Constant *getRetainRVCallee(Module *M);
Constant *getAutoreleaseRVCallee(Module *M);
Constant *getReleaseCallee(Module *M);
@@ -1505,12 +1659,13 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst,
}
MDNode *ReleaseMetadata = Inst->getMetadata(ImpreciseReleaseMDKind);
- S.ResetSequenceProgress(ReleaseMetadata ? S_MovableRelease : S_Release);
+ Sequence NewSeq = ReleaseMetadata ? S_MovableRelease : S_Release;
+ ANNOTATE_BOTTOMUP(Inst, Arg, S.GetSeq(), NewSeq);
+ S.ResetSequenceProgress(NewSeq);
S.RRI.ReleaseMetadata = ReleaseMetadata;
S.RRI.KnownSafe = S.HasKnownPositiveRefCount();
S.RRI.IsTailCallRelease = cast<CallInst>(Inst)->isTailCall();
S.RRI.Calls.insert(Inst);
-
S.SetKnownPositiveRefCount();
break;
}
@@ -1527,7 +1682,8 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst,
PtrState &S = MyStates.getPtrBottomUpState(Arg);
S.SetKnownPositiveRefCount();
- switch (S.GetSeq()) {
+ Sequence OldSeq = S.GetSeq();
+ switch (OldSeq) {
case S_Stop:
case S_Release:
case S_MovableRelease:
@@ -1548,6 +1704,7 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst,
case S_Retain:
llvm_unreachable("bottom-up pointer in retain state!");
}
+ ANNOTATE_BOTTOMUP(Inst, Arg, OldSeq, S.GetSeq());
return NestingDetected;
}
case IC_AutoreleasepoolPop:
@@ -1578,6 +1735,7 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst,
switch (Seq) {
case S_Use:
S.SetSeq(S_CanRelease);
+ ANNOTATE_BOTTOMUP(Inst, Ptr, Seq, S.GetSeq());
continue;
case S_CanRelease:
case S_Release:
@@ -1604,9 +1762,11 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst,
else
S.RRI.ReverseInsertPts.insert(llvm::next(BasicBlock::iterator(Inst)));
S.SetSeq(S_Use);
+ ANNOTATE_BOTTOMUP(Inst, Ptr, Seq, S_Use);
} else if (Seq == S_Release && IsUser(Class)) {
// Non-movable releases depend on any possible objc pointer use.
S.SetSeq(S_Stop);
+ ANNOTATE_BOTTOMUP(Inst, Ptr, S_Release, S_Stop);
assert(S.RRI.ReverseInsertPts.empty());
// As above; handle invoke specially.
if (isa<InvokeInst>(Inst))
@@ -1616,8 +1776,10 @@ ObjCARCOpt::VisitInstructionBottomUp(Instruction *Inst,
}
break;
case S_Stop:
- if (CanUse(Inst, Ptr, PA, Class))
+ if (CanUse(Inst, Ptr, PA, Class)) {
S.SetSeq(S_Use);
+ ANNOTATE_BOTTOMUP(Inst, Ptr, Seq, S_Use);
+ }
break;
case S_CanRelease:
case S_Use:
@@ -1716,6 +1878,7 @@ ObjCARCOpt::VisitInstructionTopDown(Instruction *Inst,
if (S.GetSeq() == S_Retain)
NestingDetected = true;
+ ANNOTATE_TOPDOWN(Inst, Arg, S.GetSeq(), S_Retain);
S.ResetSequenceProgress(S_Retain);
S.RRI.IsRetainBlock = Class == IC_RetainBlock;
S.RRI.KnownSafe = S.HasKnownPositiveRefCount();
@@ -1743,6 +1906,7 @@ ObjCARCOpt::VisitInstructionTopDown(Instruction *Inst,
S.RRI.ReleaseMetadata = Inst->getMetadata(ImpreciseReleaseMDKind);
S.RRI.IsTailCallRelease = cast<CallInst>(Inst)->isTailCall();
Releases[Inst] = S.RRI;
+ ANNOTATE_TOPDOWN(Inst, Arg, S.GetSeq(), S_None);
S.ClearSequenceProgress();
break;
case S_None:
@@ -1782,6 +1946,7 @@ ObjCARCOpt::VisitInstructionTopDown(Instruction *Inst,
switch (Seq) {
case S_Retain:
S.SetSeq(S_CanRelease);
+ ANNOTATE_TOPDOWN(Inst, Ptr, Seq, S_CanRelease);
assert(S.RRI.ReverseInsertPts.empty());
S.RRI.ReverseInsertPts.insert(Inst);
@@ -1803,8 +1968,10 @@ ObjCARCOpt::VisitInstructionTopDown(Instruction *Inst,
// Check for possible direct uses.
switch (Seq) {
case S_CanRelease:
- if (CanUse(Inst, Ptr, PA, Class))
+ if (CanUse(Inst, Ptr, PA, Class)) {
S.SetSeq(S_Use);
+ ANNOTATE_TOPDOWN(Inst, Ptr, Seq, S_Use);
+ }
break;
case S_Retain:
case S_Use:
@@ -2273,6 +2440,12 @@ ObjCARCOpt::PerformCodePlacement(DenseMap<const BasicBlock *, BBState>
ReleasesToMove, Arg, KnownSafe,
AnyPairsCompletelyEliminated);
+#ifdef ARC_ANNOTATIONS
+ // Do not move calls if ARC annotations are requested. If we were to move
+ // calls in this case, we would not be able
+ PerformMoveCalls = PerformMoveCalls && !EnableARCAnnotations;
+#endif // ARC_ANNOTATIONS
+
if (PerformMoveCalls) {
// Ok, everything checks out and we're all set. Let's move/delete some
// code!
@@ -2620,6 +2793,14 @@ bool ObjCARCOpt::doInitialization(Module &M) {
M.getContext().getMDKindID("clang.arc.copy_on_escape");
NoObjCARCExceptionsMDKind =
M.getContext().getMDKindID("clang.arc.no_objc_arc_exceptions");
+#ifdef ARC_ANNOTATIONS
+ ARCAnnotationBottomUpMDKind =
+ M.getContext().getMDKindID("llvm.arc.annotation.bottomup");
+ ARCAnnotationTopDownMDKind =
+ M.getContext().getMDKindID("llvm.arc.annotation.topdown");
+ ARCAnnotationProvenanceSourceMDKind =
+ M.getContext().getMDKindID("llvm.arc.annotation.provenancesource");
+#endif // ARC_ANNOTATIONS
// Intuitively, objc_retain and others are nocapture, however in practice
// they are not, because they return their argument value. And objc_release