1 //===-- UnifyFunctionExitNodes.h - Ensure fn's have one return --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This pass is used to ensure that functions have at most one return and one
11 // unwind instruction in them. Additionally, it keeps track of which node is
12 // the new exit node of the CFG. If there are no return or unwind instructions
13 // in the function, the getReturnBlock/getUnwindBlock methods will return a null
16 //===----------------------------------------------------------------------===//
18 #ifndef LLVM_TRANSFORMS_UNIFYFUNCTIONEXITNODES_H
19 #define LLVM_TRANSFORMS_UNIFYFUNCTIONEXITNODES_H
21 #include "llvm/Pass.h"
25 struct UnifyFunctionExitNodes : public FunctionPass {
26 BasicBlock *ReturnBlock, *UnwindBlock, *UnreachableBlock;
28 static char ID; // Pass identification, replacement for typeid
29 UnifyFunctionExitNodes() : FunctionPass((intptr_t)&ID),
30 ReturnBlock(0), UnwindBlock(0) {}
32 // We can preserve non-critical-edgeness when we unify function exit nodes
33 virtual void getAnalysisUsage(AnalysisUsage &AU) const;
35 // getReturn|Unwind|UnreachableBlock - Return the new single (or nonexistant)
36 // return, unwind, or unreachable basic blocks in the CFG.
38 BasicBlock *getReturnBlock() const { return ReturnBlock; }
39 BasicBlock *getUnwindBlock() const { return UnwindBlock; }
40 BasicBlock *getUnreachableBlock() const { return UnreachableBlock; }
42 virtual bool runOnFunction(Function &F);
44 // Force linking the impl of this class into anything that uses this header.
48 Pass *createUnifyFunctionExitNodesPass();
51 UNIFY_FUNCTION_EXIT_NODES_INCLUDE_FILE(&UnifyFunctionExitNodes::stub);
53 } // End llvm namespace