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