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/ADT/SmallPtrSet.h"
19
20namespace llvm {
21
22class BasicBlock;
23class Function;
24class MachineBasicBlock;
25
26namespace WebAssembly {
27enum Tag { CPP_EXCEPTION = 0, C_LONGJMP = 1 };
28}
29
30using BBOrMBB = PointerUnion<const BasicBlock *, MachineBasicBlock *>;
31
32struct WasmEHFuncInfo {
33 // When there is an entry <A, B>, if an exception is not caught by A, it
34 // should next unwind to the EH pad B.
35 DenseMap<BBOrMBB, BBOrMBB> SrcToUnwindDest;
36 DenseMap<BBOrMBB, SmallPtrSet<BBOrMBB, 4>> UnwindDestToSrcs; // reverse map
37
38 // Helper functions
39 const BasicBlock *getUnwindDest(const BasicBlock *BB) const {
40 assert(hasUnwindDest(BB));
41 return cast<const BasicBlock *>(Val: SrcToUnwindDest.lookup(Val: BB));
42 }
43 SmallPtrSet<const BasicBlock *, 4> getUnwindSrcs(const BasicBlock *BB) const {
44 assert(hasUnwindSrcs(BB));
45 const auto &Set = UnwindDestToSrcs.lookup(Val: BB);
46 SmallPtrSet<const BasicBlock *, 4> Ret;
47 for (const auto P : Set)
48 Ret.insert(Ptr: cast<const BasicBlock *>(Val: P));
49 return Ret;
50 }
51 void setUnwindDest(const BasicBlock *BB, const BasicBlock *Dest) {
52 SrcToUnwindDest[BB] = Dest;
53 UnwindDestToSrcs[Dest].insert(Ptr: BB);
54 }
55 bool hasUnwindDest(const BasicBlock *BB) const {
56 return SrcToUnwindDest.count(Val: BB);
57 }
58 bool hasUnwindSrcs(const BasicBlock *BB) const {
59 return UnwindDestToSrcs.count(Val: BB);
60 }
61
62 MachineBasicBlock *getUnwindDest(MachineBasicBlock *MBB) const {
63 assert(hasUnwindDest(MBB));
64 return cast<MachineBasicBlock *>(Val: SrcToUnwindDest.lookup(Val: MBB));
65 }
66 SmallPtrSet<MachineBasicBlock *, 4>
67 getUnwindSrcs(MachineBasicBlock *MBB) const {
68 assert(hasUnwindSrcs(MBB));
69 const auto &Set = UnwindDestToSrcs.lookup(Val: MBB);
70 SmallPtrSet<MachineBasicBlock *, 4> Ret;
71 for (const auto P : Set)
72 Ret.insert(Ptr: cast<MachineBasicBlock *>(Val: P));
73 return Ret;
74 }
75 void setUnwindDest(MachineBasicBlock *MBB, MachineBasicBlock *Dest) {
76 SrcToUnwindDest[MBB] = Dest;
77 UnwindDestToSrcs[Dest].insert(Ptr: MBB);
78 }
79 bool hasUnwindDest(MachineBasicBlock *MBB) const {
80 return SrcToUnwindDest.count(Val: MBB);
81 }
82 bool hasUnwindSrcs(MachineBasicBlock *MBB) const {
83 return UnwindDestToSrcs.count(Val: MBB);
84 }
85};
86
87// Analyze the IR in the given function to build WasmEHFuncInfo.
88void calculateWasmEHInfo(const Function *F, WasmEHFuncInfo &EHInfo);
89
90} // namespace llvm
91
92#endif // LLVM_CODEGEN_WASMEHFUNCINFO_H
93