[LLVM-C] Add bindings to insert basic blocks

Summary:
Now that we can create standalone basic blocks, it's useful to be able to append them.  Add bindings to

- Insert a basic block after the current insertion block
- Append a basic block to the end of a function's list of basic blocks

Reviewers: whitequark, deadalnix, harlanhaskins

Reviewed By: whitequark, harlanhaskins

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59658

llvm-svn: 357812

llvm/include/llvm-c/Core.h

@@ -2916,6 +2916,24 @@ LLVMBasicBlockRef LLVMGetPreviousBasicBlock(LLVMBasicBlockRef BB);
  */
 LLVMBasicBlockRef LLVMGetEntryBasicBlock(LLVMValueRef Fn);
 
+/**
+ * Insert the given basic block after the insertion point of the given builder.
+ *
+ * The insertion point must be valid.
+ *
+ * @see llvm::Function::BasicBlockListType::insertAfter()
+ */
+void LLVMInsertExistingBasicBlockAfterInsertBlock(LLVMBuilderRef Builder,
+                                                  LLVMBasicBlockRef BB);
+
+/**
+ * Append the given basic block to the basic block list of the given function.
+ *
+ * @see llvm::Function::BasicBlockListType::push_back()
+ */
+void LLVMAppendExistingBasicBlock(LLVMValueRef Fn,
+                                  LLVMBasicBlockRef BB);
+  
 /**
  * Create a new basic block without inserting it into a function.
  *

llvm/lib/IR/Core.cpp

@@ -2609,6 +2609,20 @@ LLVMBasicBlockRef LLVMCreateBasicBlockInContext(LLVMContextRef C,
   return wrap(llvm::BasicBlock::Create(*unwrap(C), Name));
 }
 
+void LLVMInsertExistingBasicBlockAfterInsertBlock(LLVMBuilderRef Builder,
+                                                  LLVMBasicBlockRef BB) {
+  BasicBlock *ToInsert = unwrap(BB);
+  BasicBlock *CurBB = unwrap(Builder)->GetInsertBlock();
+  assert(CurBB && "current insertion point is invalid!");
+  CurBB->getParent()->getBasicBlockList().insertAfter(CurBB->getIterator(),
+                                                      ToInsert);
+}
+
+void LLVMAppendExistingBasicBlock(LLVMValueRef Fn,
+                                  LLVMBasicBlockRef BB) {
+  unwrap<Function>(Fn)->getBasicBlockList().push_back(unwrap(BB));
+}
+
 LLVMBasicBlockRef LLVMAppendBasicBlockInContext(LLVMContextRef C,
                                                 LLVMValueRef FnRef,
                                                 const char *Name) {