[IR] Adds Function::splice() member functions

This is part of a series of patches that aim at making Function::getBasicBlockList() private.

Differential Revision: https://reviews.llvm.org/D139982

1 files changed, 12 insertions, 0 deletions

diff --git a/llvm/lib/IR/Function.cpp b/llvm/lib/IR/Function.cpp
index 10bbdcf..949eb05 100644
--- a/llvm/lib/IR/Function.cpp
+++ b/llvm/lib/IR/Function.cpp
@@ -368,6 +368,18 @@ void Function::eraseFromParent() {
   getParent()->getFunctionList().erase(getIterator());
 }
 
+void Function::splice(Function::iterator ToIt, Function *FromF,
+                      Function::iterator FromBeginIt,
+                      Function::iterator FromEndIt) {
+#ifdef EXPENSIVE_CHECKS
+  // Check that FromBeginIt is before FromEndIt.
+  auto FromFEnd = FromF->end();
+  for (auto It = FromBeginIt; It != FromEndIt; ++It)
+    assert(It != FromBBEnd && "FromBeginIt not before FromEndIt!");
+#endif // EXPENSIVE_CHECKS
+  BasicBlocks.splice(ToIt, FromF->BasicBlocks, FromBeginIt, FromEndIt);
+}
+
 //===----------------------------------------------------------------------===//
 // Function Implementation
 //===----------------------------------------------------------------------===//