lib/CodeGen/AsmPrinter/AddressPool.h

   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() { HasBeenUsed = false; }
  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