//===--- llvm/CodeGen/WasmEHFuncInfo.h --------------------------*- C++ -*-===//
 
//
 
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 
// See https://llvm.org/LICENSE.txt for license information.
 
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
//
 
//===----------------------------------------------------------------------===//
 
//
 
// Data structures for Wasm exception handling schemes.
 
//
 
//===----------------------------------------------------------------------===//
 
 
 
#ifndef LLVM_CODEGEN_WASMEHFUNCINFO_H
 
#define LLVM_CODEGEN_WASMEHFUNCINFO_H
 
 
 
#include "llvm/ADT/DenseMap.h"
 
#include "llvm/ADT/PointerUnion.h"
 
#include "llvm/ADT/SmallPtrSet.h"
 
 
 
namespace llvm {
 
 
 
class BasicBlock;
 
class Function;
 
class MachineBasicBlock;
 
 
 
namespace WebAssembly {
 
enum Tag { CPP_EXCEPTION = 0, C_LONGJMP = 1 };
 
}
 
 
 
using BBOrMBB = PointerUnion<const BasicBlock *, MachineBasicBlock *>;
 
 
 
struct WasmEHFuncInfo {
 
  // When there is an entry <A, B>, if an exception is not caught by A, it
 
  // should next unwind to the EH pad B.
 
  DenseMap<BBOrMBB, BBOrMBB> SrcToUnwindDest;
 
  DenseMap<BBOrMBB, SmallPtrSet<BBOrMBB, 4>> UnwindDestToSrcs; // reverse map
 
 
 
  // Helper functions
 
  const BasicBlock *getUnwindDest(const BasicBlock *BB) const {
 
    assert(hasUnwindDest(BB));
 
    return SrcToUnwindDest.lookup(BB).get<const BasicBlock *>();
 
  }
 
  SmallPtrSet<const BasicBlock *, 4> getUnwindSrcs(const BasicBlock *BB) const {
 
    assert(hasUnwindSrcs(BB));
 
    const auto &Set = UnwindDestToSrcs.lookup(BB);
 
    SmallPtrSet<const BasicBlock *, 4> Ret;
 
    for (const auto P : Set)
 
      Ret.insert(P.get<const BasicBlock *>());
 
    return Ret;
 
  }
 
  void setUnwindDest(const BasicBlock *BB, const BasicBlock *Dest) {
 
    SrcToUnwindDest[BB] = Dest;
 
    UnwindDestToSrcs[Dest].insert(BB);
 
  }
 
  bool hasUnwindDest(const BasicBlock *BB) const {
 
    return SrcToUnwindDest.count(BB);
 
  }
 
  bool hasUnwindSrcs(const BasicBlock *BB) const {
 
    return UnwindDestToSrcs.count(BB);
 
  }
 
 
 
  MachineBasicBlock *getUnwindDest(MachineBasicBlock *MBB) const {
 
    assert(hasUnwindDest(MBB));
 
    return SrcToUnwindDest.lookup(MBB).get<MachineBasicBlock *>();
 
  }
 
  SmallPtrSet<MachineBasicBlock *, 4>
 
  getUnwindSrcs(MachineBasicBlock *MBB) const {
 
    assert(hasUnwindSrcs(MBB));
 
    const auto &Set = UnwindDestToSrcs.lookup(MBB);
 
    SmallPtrSet<MachineBasicBlock *, 4> Ret;
 
    for (const auto P : Set)
 
      Ret.insert(P.get<MachineBasicBlock *>());
 
    return Ret;
 
  }
 
  void setUnwindDest(MachineBasicBlock *MBB, MachineBasicBlock *Dest) {
 
    SrcToUnwindDest[MBB] = Dest;
 
    UnwindDestToSrcs[Dest].insert(MBB);
 
  }
 
  bool hasUnwindDest(MachineBasicBlock *MBB) const {
 
    return SrcToUnwindDest.count(MBB);
 
  }
 
  bool hasUnwindSrcs(MachineBasicBlock *MBB) const {
 
    return UnwindDestToSrcs.count(MBB);
 
  }
 
};
 
 
 
// Analyze the IR in the given function to build WasmEHFuncInfo.
 
void calculateWasmEHInfo(const Function *F, WasmEHFuncInfo &EHInfo);
 
 
 
} // namespace llvm
 
 
 
#endif // LLVM_CODEGEN_WASMEHFUNCINFO_H