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      1 //===- llvm/CodeGen/AddressPool.h - Dwarf Debug Framework -------*- 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 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_ADDRESSPOOL_H
     10 #define LLVM_LIB_CODEGEN_ASMPRINTER_ADDRESSPOOL_H
     11 
     12 #include "llvm/ADT/DenseMap.h"
     13 
     14 namespace llvm {
     15 
     16 class AsmPrinter;
     17 class MCSection;
     18 class MCSymbol;
     19 
     20 // Collection of addresses for this unit and assorted labels.
     21 // A Symbol->unsigned mapping of addresses used by indirect
     22 // references.
     23 class AddressPool {
     24   struct AddressPoolEntry {
     25     unsigned Number;
     26     bool TLS;
     27 
     28     AddressPoolEntry(unsigned Number, bool TLS) : Number(Number), TLS(TLS) {}
     29   };
     30   DenseMap<const MCSymbol *, AddressPoolEntry> Pool;
     31 
     32   /// Record whether the AddressPool has been queried for an address index since
     33   /// the last "resetUsedFlag" call. Used to implement type unit fallback - a
     34   /// type that references addresses cannot be placed in a type unit when using
     35   /// fission.
     36   bool HasBeenUsed = false;
     37 
     38 public:
     39   AddressPool() = default;
     40 
     41   /// Returns the index into the address pool with the given
     42   /// label/symbol.
     43   unsigned getIndex(const MCSymbol *Sym, bool TLS = false);
     44 
     45   void emit(AsmPrinter &Asm, MCSection *AddrSection);
     46 
     47   bool isEmpty() { return Pool.empty(); }
     48 
     49   bool hasBeenUsed() const { return HasBeenUsed; }
     50 
     51   void resetUsedFlag(bool HasBeenUsed = false) { this->HasBeenUsed = HasBeenUsed; }
     52 
     53   MCSymbol *getLabel() { return AddressTableBaseSym; }
     54   void setLabel(MCSymbol *Sym) { AddressTableBaseSym = Sym; }
     55 
     56 private:
     57   MCSymbol *emitHeader(AsmPrinter &Asm, MCSection *Section);
     58 
     59   /// Symbol designates the start of the contribution to the address table.
     60   MCSymbol *AddressTableBaseSym = nullptr;
     61 };
     62 
     63 } // end namespace llvm
     64 
     65 #endif // LLVM_LIB_CODEGEN_ASMPRINTER_ADDRESSPOOL_H
     66