IR: Remove MDNodeFwdDecl

Remove `MDNodeFwdDecl` (as promised in r226481).  Aside from API
changes, there's no real functionality change here.
`MDNode::getTemporary()` now forwards to `MDTuple::getTemporary()`,
which returns a tuple with `isTemporary()` equal to true.

The main point is that we can now add temporaries of other `MDNode`
subclasses, needed for PR22235 (I introduced `MDNodeFwdDecl` in the
first place because I didn't recognize this need, and thought they were
only needed to handle forward references).

A few things left out of (or highlighted by) this commit:

  - I've had to remove the (few) uses of `std::unique_ptr<>` to deal
    with temporaries, since the destructor is no longer public.
    `getTemporary()` should probably return the equivalent of
    `std::unique_ptr<T, MDNode::deleteTemporary>`.
  - `MDLocation::getTemporary()` doesn't exist yet (worse, it actually
    does exist, but does the wrong thing: `MDNode::getTemporary()` is
    inherited and returns an `MDTuple`).
  - `MDNode` now only has one subclass, `UniquableMDNode`, and the
    distinction between them is actually somewhat confusing.

I'll fix those up next.

llvm-svn: 226501

1 files changed, 15 insertions, 16 deletions

diff --git a/llvm/unittests/IR/MetadataTest.cpp b/llvm/unittests/IR/MetadataTest.cpp
index 2de1f06aef7..9515f0de4ff 100644
--- a/llvm/unittests/IR/MetadataTest.cpp
+++ b/llvm/unittests/IR/MetadataTest.cpp
@@ -167,10 +167,6 @@ TEST_F(MDNodeTest, Delete) {
   delete I;
 }
 
-TEST_F(MDNodeTest, DeleteMDNodeFwdDecl) {
-  delete MDNode::getTemporary(Context, None);
-}
-
 TEST_F(MDNodeTest, SelfReference) {
   // !0 = !{!0}
   // !1 = !{!0}
@@ -343,7 +339,7 @@ TEST_F(MDNodeTest, isTemporary) {
 
 TEST_F(MDNodeTest, getDistinctWithUnresolvedOperands) {
   // temporary !{}
-  MDNodeFwdDecl *Temp = MDNode::getTemporary(Context, None);
+  MDTuple *Temp = MDTuple::getTemporary(Context, None);
   ASSERT_FALSE(Temp->isResolved());
 
   // distinct !{temporary !{}}
@@ -364,18 +360,19 @@ TEST_F(MDNodeTest, handleChangedOperandRecursion) {
   MDNode *N0 = MDNode::get(Context, None);
 
   // !1 = !{!3, null}
-  std::unique_ptr<MDNodeFwdDecl> Temp3(MDNode::getTemporary(Context, None));
-  Metadata *Ops1[] = {Temp3.get(), nullptr};
+  MDTuple *Temp3 = MDTuple::getTemporary(Context, None);
+  Metadata *Ops1[] = {Temp3, nullptr};
   MDNode *N1 = MDNode::get(Context, Ops1);
 
   // !2 = !{!3, !0}
-  Metadata *Ops2[] = {Temp3.get(), N0};
+  Metadata *Ops2[] = {Temp3, N0};
   MDNode *N2 = MDNode::get(Context, Ops2);
 
   // !3 = !{!2}
   Metadata *Ops3[] = {N2};
   MDNode *N3 = MDNode::get(Context, Ops3);
   Temp3->replaceAllUsesWith(N3);
+  MDNode::deleteTemporary(Temp3);
 
   // !4 = !{!1}
   Metadata *Ops4[] = {N1};
@@ -428,8 +425,8 @@ TEST_F(MDNodeTest, replaceResolvedOperand) {
   // a global value that gets RAUW'ed.
   //
   // Use a temporary node to keep N from being resolved.
-  std::unique_ptr<MDNodeFwdDecl> Temp(MDNodeFwdDecl::get(Context, None));
-  Metadata *Ops[] = {nullptr, Temp.get()};
+  MDTuple *Temp = MDTuple::getTemporary(Context, None);
+  Metadata *Ops[] = {nullptr, Temp};
 
   MDNode *Empty = MDTuple::get(Context, ArrayRef<Metadata *>());
   MDNode *N = MDTuple::get(Context, Ops);
@@ -441,11 +438,12 @@ TEST_F(MDNodeTest, replaceResolvedOperand) {
   EXPECT_EQ(Empty, N->getOperand(0));
 
   // Check code for adding another unresolved operand.
-  N->replaceOperandWith(0, Temp.get());
-  EXPECT_EQ(Temp.get(), N->getOperand(0));
+  N->replaceOperandWith(0, Temp);
+  EXPECT_EQ(Temp, N->getOperand(0));
 
   // Remove the references to Temp; required for teardown.
   Temp->replaceAllUsesWith(nullptr);
+  MDNode::deleteTemporary(Temp);
 }
 
 typedef MetadataTest MDLocationTest;
@@ -551,11 +549,11 @@ TEST_F(ValueAsMetadataTest, CollidingDoubleUpdates) {
       ConstantInt::get(getGlobalContext(), APInt(8, 0)));
 
   // Create a temporary to prevent nodes from resolving.
-  std::unique_ptr<MDNodeFwdDecl> Temp(MDNode::getTemporary(Context, None));
+  MDTuple *Temp = MDTuple::getTemporary(Context, None);
 
   // When the first operand of N1 gets reset to nullptr, it'll collide with N2.
-  Metadata *Ops1[] = {CI, CI, Temp.get()};
-  Metadata *Ops2[] = {nullptr, CI, Temp.get()};
+  Metadata *Ops1[] = {CI, CI, Temp};
+  Metadata *Ops2[] = {nullptr, CI, Temp};
 
   auto *N1 = MDTuple::get(Context, Ops1);
   auto *N2 = MDTuple::get(Context, Ops2);
@@ -567,10 +565,11 @@ TEST_F(ValueAsMetadataTest, CollidingDoubleUpdates) {
   ValueAsMetadata::handleDeletion(CI->getValue());
   EXPECT_EQ(nullptr, N2->getOperand(0));
   EXPECT_EQ(nullptr, N2->getOperand(1));
-  EXPECT_EQ(Temp.get(), N2->getOperand(2));
+  EXPECT_EQ(Temp, N2->getOperand(2));
 
   // Clean up Temp for teardown.
   Temp->replaceAllUsesWith(nullptr);
+  MDNode::deleteTemporary(Temp);
 }
 
 typedef MetadataTest TrackingMDRefTest;