[LLVM-C] Move DIBuilder Bindings For Temporary MDNodes

Summary: Move LLVMTemporaryMDNode and LLVMMetadataReplaceAllUsesWith to the C bindings and add LLVMDeleteTemporaryMDNode for deleting non-RAUW'ed temporary nodes.

Reviewers: whitequark, harlanhaskins, deadalnix

Reviewed By: whitequark

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D46632

llvm-svn: 332010

llvm/bindings/go/llvm/IRBindings.cpp

@@ -36,13 +36,6 @@ LLVMMetadataRef LLVMMDNode2(LLVMContextRef C, LLVMMetadataRef *MDs,
       MDNode::get(*unwrap(C), ArrayRef<Metadata *>(unwrap(MDs), Count)));
 }
 
-LLVMMetadataRef LLVMTemporaryMDNode(LLVMContextRef C, LLVMMetadataRef *MDs,
-                                    unsigned Count) {
-  return wrap(MDTuple::getTemporary(*unwrap(C),
-                                    ArrayRef<Metadata *>(unwrap(MDs), Count))
-                  .release());
-}
-
 void LLVMAddNamedMetadataOperand2(LLVMModuleRef M, const char *name,
                                   LLVMMetadataRef Val) {
   NamedMDNode *N = unwrap(M)->getOrInsertNamedMetadata(name);
@@ -58,12 +51,6 @@ void LLVMSetMetadata2(LLVMValueRef Inst, unsigned KindID, LLVMMetadataRef MD) {
   unwrap<Instruction>(Inst)->setMetadata(KindID, N);
 }
 
-void LLVMMetadataReplaceAllUsesWith(LLVMMetadataRef MD, LLVMMetadataRef New) {
-  auto *Node = unwrap<MDNode>(MD);
-  Node->replaceAllUsesWith(unwrap<Metadata>(New));
-  MDNode::deleteTemporary(Node);
-}
-
 void LLVMSetCurrentDebugLocation2(LLVMBuilderRef Bref, unsigned Line,
                                   unsigned Col, LLVMMetadataRef Scope,
                                   LLVMMetadataRef InlinedAt) {

llvm/bindings/go/llvm/IRBindings.h

@@ -38,15 +38,11 @@ LLVMMetadataRef LLVMConstantAsMetadata(LLVMValueRef Val);
 LLVMMetadataRef LLVMMDString2(LLVMContextRef C, const char *Str, unsigned SLen);
 LLVMMetadataRef LLVMMDNode2(LLVMContextRef C, LLVMMetadataRef *MDs,
                             unsigned Count);
-LLVMMetadataRef LLVMTemporaryMDNode(LLVMContextRef C, LLVMMetadataRef *MDs,
-                                    unsigned Count);
 
 void LLVMAddNamedMetadataOperand2(LLVMModuleRef M, const char *name,
                                   LLVMMetadataRef Val);
 void LLVMSetMetadata2(LLVMValueRef Inst, unsigned KindID, LLVMMetadataRef MD);
 
-void LLVMMetadataReplaceAllUsesWith(LLVMMetadataRef MD, LLVMMetadataRef New);
-
 void LLVMSetCurrentDebugLocation2(LLVMBuilderRef Bref, unsigned Line,
                                   unsigned Col, LLVMMetadataRef Scope,
                                   LLVMMetadataRef InlinedAt);

llvm/bindings/go/llvm/dibuilder.go

@@ -585,3 +585,17 @@ func boolToCInt(v bool) C.int {
 	}
 	return 0
 }
+
+//-------------------------------------------------------------------------
+// llvm.Metadata
+//-------------------------------------------------------------------------
+
+func (c Context) TemporaryMDNode(mds []Metadata) (md Metadata) {
+	ptr, nvals := llvmMetadataRefs(mds)
+	md.C = C.LLVMTemporaryMDNode(c.C, ptr, C.size_t(nvals))
+	return
+}
+
+func (md Metadata) ReplaceAllUsesWith(new Metadata) {
+	C.LLVMMetadataReplaceAllUsesWith(md.C, new.C)
+}

llvm/bindings/go/llvm/ir.go

@@ -784,11 +784,6 @@ func (c Context) MDNode(mds []Metadata) (md Metadata) {
 	md.C = C.LLVMMDNode2(c.C, ptr, nvals)
 	return
 }
-func (c Context) TemporaryMDNode(mds []Metadata) (md Metadata) {
-	ptr, nvals := llvmMetadataRefs(mds)
-	md.C = C.LLVMTemporaryMDNode(c.C, ptr, nvals)
-	return
-}
 func (v Value) ConstantAsMetadata() (md Metadata) {
 	md.C = C.LLVMConstantAsMetadata(v.C)
 	return
@@ -1916,11 +1911,3 @@ func (pm PassManager) FinalizeFunc() bool { return C.LLVMFinalizeFunctionPassMan
 // the module provider.
 // See llvm::PassManagerBase::~PassManagerBase.
 func (pm PassManager) Dispose() { C.LLVMDisposePassManager(pm.C) }
-
-//-------------------------------------------------------------------------
-// llvm.Metadata
-//-------------------------------------------------------------------------
-
-func (md Metadata) ReplaceAllUsesWith(new Metadata) {
-	C.LLVMMetadataReplaceAllUsesWith(md.C, new.C)
-}

llvm/include/llvm-c/DebugInfo.h

@@ -830,6 +830,33 @@ LLVMDIBuilderCreateGlobalVariableExpression(LLVMDIBuilderRef Builder,
                                             LLVMMetadataRef Expr,
                                             LLVMMetadataRef Decl,
                                             uint32_t AlignInBits);
+/**
+ * Create a new temporary \c MDNode.  Suitable for use in constructing cyclic
+ * \c MDNode structures. A temporary \c MDNode is not uniqued, may be RAUW'd,
+ * and must be manually deleted with \c LLVMDisposeTemporaryMDNode.
+ * \param Ctx            The context in which to construct the temporary node.
+ * \param Data           The metadata elements.
+ * \param NumElements    Number of metadata elements.
+ */
+LLVMMetadataRef LLVMTemporaryMDNode(LLVMContextRef Ctx, LLVMMetadataRef *Data,
+                                    size_t NumElements);
+
+/**
+ * Deallocate a temporary node.
+ *
+ * Calls \c replaceAllUsesWith(nullptr) before deleting, so any remaining
+ * references will be reset.
+ * \param TempNode    The temporary metadata node.
+ */
+void LLVMDisposeTemporaryMDNode(LLVMMetadataRef TempNode);
+
+/**
+ * Replace all uses of temporary metadata.
+ * \param TempTargetMetadata    The temporary metadata node.
+ * \param Replacement           The replacement metadata node.
+ */
+void LLVMMetadataReplaceAllUsesWith(LLVMMetadataRef TempTargetMetadata,
+                                    LLVMMetadataRef Replacement);
 
 /**
  * Create a new descriptor for the specified global variable that is temporary

llvm/lib/IR/DebugInfo.cpp

@@ -1152,6 +1152,23 @@ LLVMDIBuilderCreateGlobalVariableExpression(LLVMDIBuilderRef Builder,
                   unwrapDI<MDNode>(Decl), AlignInBits));
 }
 
+LLVMMetadataRef LLVMTemporaryMDNode(LLVMContextRef Ctx, LLVMMetadataRef *Data,
+                                    size_t Count) {
+  return wrap(
+      MDTuple::getTemporary(*unwrap(Ctx), {unwrap(Data), Count}).release());
+}
+
+void LLVMDisposeTemporaryMDNode(LLVMMetadataRef TempNode) {
+  MDNode::deleteTemporary(unwrapDI<MDNode>(TempNode));
+}
+
+void LLVMMetadataReplaceAllUsesWith(LLVMMetadataRef TargetMetadata,
+                                    LLVMMetadataRef Replacement) {
+  auto *Node = unwrapDI<MDNode>(TargetMetadata);
+  Node->replaceAllUsesWith(unwrap<Metadata>(Replacement));
+  MDNode::deleteTemporary(Node);
+}
+
 LLVMMetadataRef
 LLVMDIBuilderCreateTempGlobalVariableFwdDecl(LLVMDIBuilderRef Builder,
                                              LLVMMetadataRef Scope,

llvm/tools/llvm-c-test/debuginfo.c

@@ -93,14 +93,23 @@ int llvm_test_dibuilder(void) {
   LLVMMetadataRef ParamTypes[] = {Int64Ty, Int64Ty, VectorTy};
   LLVMMetadataRef FunctionTy =
     LLVMDIBuilderCreateSubroutineType(DIB, File, ParamTypes, 3, 0);
+
+  LLVMMetadataRef ReplaceableFunctionMetadata =
+    LLVMDIBuilderCreateReplaceableCompositeType(DIB, 0x15, "foo", 3,
+                                                File, File, 42,
+                                                0, 0, 0,
+                                                LLVMDIFlagFwdDecl,
+                                                "", 0);
+
+  LLVMMetadataRef FooParamLocation =
+    LLVMDIBuilderCreateDebugLocation(LLVMGetGlobalContext(), 42, 0,
+                                     ReplaceableFunctionMetadata, NULL);
   LLVMMetadataRef FunctionMetadata =
     LLVMDIBuilderCreateFunction(DIB, File, "foo", 3, "foo", 3,
                                 File, 42, FunctionTy, true, true,
                                 42, 0, false);
+  LLVMMetadataReplaceAllUsesWith(ReplaceableFunctionMetadata, FunctionMetadata);
 
-  LLVMMetadataRef FooParamLocation =
-    LLVMDIBuilderCreateDebugLocation(LLVMGetGlobalContext(), 42, 0,
-                                     FunctionMetadata, NULL);
   LLVMMetadataRef FooParamExpression =
     LLVMDIBuilderCreateExpression(DIB, NULL, 0);
   LLVMMetadataRef FooParamVar1 =