include/llvm/CodeGen/WasmEHFuncInfo.h

   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   // For entry <A, B>, A is a BB with an instruction that may throw
  32   // (invoke/cleanupret in LLVM IR, call/rethrow in the backend) and B is an EH
  33   // pad that A unwinds to.
  34   DenseMap<BBOrMBB, BBOrMBB> ThrowUnwindMap;
  35
  36   // Helper functions
  37   const BasicBlock *getEHPadUnwindDest(const BasicBlock *BB) const {
  38     return EHPadUnwindMap.lookup(BB).get<const BasicBlock *>();
  39   }
  40   void setEHPadUnwindDest(const BasicBlock *BB, const BasicBlock *Dest) {
  41     EHPadUnwindMap[BB] = Dest;
  42   }
  43   const BasicBlock *getThrowUnwindDest(BasicBlock *BB) const {
  44     return ThrowUnwindMap.lookup(BB).get<const BasicBlock *>();
  45   }
  46   void setThrowUnwindDest(const BasicBlock *BB, const BasicBlock *Dest) {
  47     ThrowUnwindMap[BB] = Dest;
  48   }
  49   bool hasEHPadUnwindDest(const BasicBlock *BB) const {
  50     return EHPadUnwindMap.count(BB);
  51   }
  52   bool hasThrowUnwindDest(const BasicBlock *BB) const {
  53     return ThrowUnwindMap.count(BB);
  54   }
  55
  56   MachineBasicBlock *getEHPadUnwindDest(MachineBasicBlock *MBB) const {
  57     return EHPadUnwindMap.lookup(MBB).get<MachineBasicBlock *>();
  58   }
  59   void setEHPadUnwindDest(MachineBasicBlock *MBB, MachineBasicBlock *Dest) {
  60     EHPadUnwindMap[MBB] = Dest;
  61   }
  62   MachineBasicBlock *getThrowUnwindDest(MachineBasicBlock *MBB) const {
  63     return ThrowUnwindMap.lookup(MBB).get<MachineBasicBlock *>();
  64   }
  65   void setThrowUnwindDest(MachineBasicBlock *MBB, MachineBasicBlock *Dest) {
  66     ThrowUnwindMap[MBB] = Dest;
  67   }
  68   bool hasEHPadUnwindDest(MachineBasicBlock *MBB) const {
  69     return EHPadUnwindMap.count(MBB);
  70   }
  71   bool hasThrowUnwindDest(MachineBasicBlock *MBB) const {
  72     return ThrowUnwindMap.count(MBB);
  73   }
  74 };
  75
  76 // Analyze the IR in the given function to build WasmEHFuncInfo.
  77 void calculateWasmEHInfo(const Function *F, WasmEHFuncInfo &EHInfo);
  78
  79 } // namespace llvm
  80
  81 #endif // LLVM_CODEGEN_WASMEHFUNCINFO_H