[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

1 files changed, 27 insertions, 0 deletions

diff --git a/llvm/include/llvm-c/DebugInfo.h b/llvm/include/llvm-c/DebugInfo.h
index fff7bd56925..6d5e7fe8b11 100644
--- a/llvm/include/llvm-c/DebugInfo.h
+++ b/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