1 //===-- EscapeEnumerator.h --------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Defines a helper class that enumerates all possible exits from a function,
10 // including exception handling.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_TRANSFORMS_UTILS_ESCAPEENUMERATOR_H
15 #define LLVM_TRANSFORMS_UTILS_ESCAPEENUMERATOR_H
16 
17 #include "llvm/IR/Function.h"
18 #include "llvm/IR/IRBuilder.h"
19 
20 namespace llvm {
21 
22 class DomTreeUpdater;
23 
24 /// EscapeEnumerator - This is a little algorithm to find all escape points
25 /// from a function so that "finally"-style code can be inserted. In addition
26 /// to finding the existing return and unwind instructions, it also (if
27 /// necessary) transforms any call instructions into invokes and sends them to
28 /// a landing pad.
29 class EscapeEnumerator {
30   Function &F;
31   const char *CleanupBBName;
32 
33   Function::iterator StateBB, StateE;
34   IRBuilder<> Builder;
35   bool Done;
36   bool HandleExceptions;
37 
38   DomTreeUpdater *DTU;
39 
40 public:
41   EscapeEnumerator(Function &F, const char *N = "cleanup",
42                    bool HandleExceptions = true, DomTreeUpdater *DTU = nullptr)
F(F)43       : F(F), CleanupBBName(N), StateBB(F.begin()), StateE(F.end()),
44         Builder(F.getContext()), Done(false),
45         HandleExceptions(HandleExceptions), DTU(DTU) {}
46 
47   IRBuilder<> *Next();
48 };
49 
50 }
51 
52 #endif // LLVM_TRANSFORMS_UTILS_ESCAPEENUMERATOR_H
53