1 //===--- llvm/CodeGen/WasmEHFuncInfo.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 // Data structures for Wasm exception handling schemes.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CODEGEN_WASMEHFUNCINFO_H
14 #define LLVM_CODEGEN_WASMEHFUNCINFO_H
15 
16 #include "llvm/ADT/DenseMap.h"
17 #include "llvm/ADT/PointerUnion.h"
18 #include "llvm/CodeGen/MachineBasicBlock.h"
19 #include "llvm/IR/BasicBlock.h"
20 
21 namespace llvm {
22 
23 enum EventTag { CPP_EXCEPTION = 0, C_LONGJMP = 1 };
24 
25 using BBOrMBB = PointerUnion<const BasicBlock *, MachineBasicBlock *>;
26 
27 struct WasmEHFuncInfo {
28   // When there is an entry <A, B>, if an exception is not caught by A, it
29   // should next unwind to the EH pad B.
30   DenseMap<BBOrMBB, BBOrMBB> EHPadUnwindMap;
31 
32   // Helper functions
33   const BasicBlock *getEHPadUnwindDest(const BasicBlock *BB) const {
34     return EHPadUnwindMap.lookup(BB).get<const BasicBlock *>();
35   }
36   void setEHPadUnwindDest(const BasicBlock *BB, const BasicBlock *Dest) {
37     EHPadUnwindMap[BB] = Dest;
38   }
39   bool hasEHPadUnwindDest(const BasicBlock *BB) const {
40     return EHPadUnwindMap.count(BB);
41   }
42 
43   MachineBasicBlock *getEHPadUnwindDest(MachineBasicBlock *MBB) const {
44     return EHPadUnwindMap.lookup(MBB).get<MachineBasicBlock *>();
45   }
46   void setEHPadUnwindDest(MachineBasicBlock *MBB, MachineBasicBlock *Dest) {
47     EHPadUnwindMap[MBB] = Dest;
48   }
49   bool hasEHPadUnwindDest(MachineBasicBlock *MBB) const {
50     return EHPadUnwindMap.count(MBB);
51   }
52 };
53 
54 // Analyze the IR in the given function to build WasmEHFuncInfo.
55 void calculateWasmEHInfo(const Function *F, WasmEHFuncInfo &EHInfo);
56 
57 } // namespace llvm
58 
59 #endif // LLVM_CODEGEN_WASMEHFUNCINFO_H
60