1//===- DWARFLinkerTypeUnit.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#ifndef LLVM_DWARFLINKER_PARALLEL_DWARFLINKERTYPEUNIT_H
10#define LLVM_DWARFLINKER_PARALLEL_DWARFLINKERTYPEUNIT_H
11
12#include "DWARFLinkerUnit.h"
13#include "llvm/CodeGen/DIE.h"
14#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
15#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
16
17namespace llvm {
18namespace dwarf_linker {
19namespace parallel {
20
21/// Type Unit is used to represent an artificial compilation unit
22/// which keeps all type information. This type information is referenced
23/// from other compilation units.
24class TypeUnit : public DwarfUnit {
25public:
26 TypeUnit(LinkingGlobalData &GlobalData, unsigned ID,
27 std::optional<uint16_t> Language, dwarf::FormParams Format,
28 llvm::endianness Endianess);
29
30 /// Generates DIE tree based on information from TypesMap.
31 void createDIETree(BumpPtrAllocator &Allocator);
32
33 /// Emits resulting dwarf based on information from DIE tree.
34 Error finishCloningAndEmit(const Triple &TargetTriple);
35
36 /// Returns global type pool.
37 TypePool &getTypePool() { return Types; }
38
39 /// TypeUnitAccelInfo extends AccelInfo structure with type specific fileds.
40 /// We need these additional fields to decide whether OutDIE should have an
41 /// accelerator record or not. The TypeEntryBodyPtr can refer to the
42 /// declaration DIE and definition DIE corresponding to the type entry.
43 /// Only one of them would be used in final output. So if TypeUnitAccelInfo
44 /// refers OutDIE which does not match with TypeEntryBodyPtr->getFinalDie()
45 /// then such record should be skipped.
46 struct TypeUnitAccelInfo : public AccelInfo {
47 /// Pointer to the output DIE which owns this accelerator record.
48 DIE *OutDIE = nullptr;
49
50 /// Pointer to the type entry body.
51 TypeEntryBody *TypeEntryBodyPtr = nullptr;
52 };
53
54 /// Enumerates all accelerator records and call \p Handler for each.
55 void
56 forEachAcceleratorRecord(function_ref<void(AccelInfo &)> Handler) override {
57 AcceleratorRecords.forEach(Handler: [&](TypeUnitAccelInfo &Info) {
58 // Check whether current record is for the final DIE.
59 assert(Info.TypeEntryBodyPtr != nullptr);
60
61 if (&Info.TypeEntryBodyPtr->getFinalDie() != Info.OutDIE)
62 return;
63
64 Info.OutOffset = Info.OutDIE->getOffset();
65 Handler(Info);
66 });
67 }
68
69 /// Returns index for the specified \p String inside .debug_str_offsets.
70 uint64_t getDebugStrIndex(const StringEntry *String) override {
71 std::unique_lock<std::mutex> LockGuard(DebugStringIndexMapMutex);
72 return DebugStringIndexMap.getValueIndex(Value: String);
73 }
74
75 /// Adds \p Info to the unit's accelerator records.
76 void saveAcceleratorInfo(const TypeUnitAccelInfo &Info) {
77 AcceleratorRecords.add(Item: Info);
78 }
79
80private:
81 /// Type DIEs are partially created at clonning stage. They are organised
82 /// as a tree using type entries. This function links DIEs(corresponding
83 /// to the type entries) into the tree structure.
84 uint64_t finalizeTypeEntryRec(uint64_t OutOffset, DIE *OutDIE,
85 TypeEntry *Entry);
86
87 /// Prepares DIEs to be linked into the tree.
88 void prepareDataForTreeCreation();
89
90 /// Add specified \p Dir and \p Filename into the line table
91 /// of this type unit.
92 uint32_t addFileNameIntoLinetable(StringEntry *Dir, StringEntry *FileName);
93
94 std::pair<dwarf::Form, uint8_t> getScalarFormForValue(uint64_t Value) const;
95
96 uint8_t getSizeByAttrForm(dwarf::Form Form) const;
97
98 struct CmpStringEntryRef {
99 bool operator()(const StringEntry *LHS, const StringEntry *RHS) const {
100 return LHS->first() < RHS->first();
101 }
102 };
103 struct CmpDirIDStringEntryRef {
104 bool operator()(const std::pair<StringEntry *, uint64_t> &LHS,
105 const std::pair<StringEntry *, uint64_t> &RHS) const {
106 return LHS.second < RHS.second ||
107 (!(RHS.second < LHS.second) &&
108 LHS.first->first() < RHS.first->first());
109 }
110 };
111
112 /// The DW_AT_language of this unit.
113 std::optional<uint16_t> Language;
114
115 /// This unit line table.
116 DWARFDebugLine::LineTable LineTable;
117
118 /// Data members keeping file names for line table.
119 using DirectoriesMapTy = std::map<StringEntry *, size_t, CmpStringEntryRef>;
120 using FilenamesMapTy = std::map<std::pair<StringEntry *, uint64_t>, size_t,
121 CmpDirIDStringEntryRef>;
122
123 DirectoriesMapTy DirectoriesMap;
124 FilenamesMapTy FileNamesMap;
125
126 /// Type DIEs tree.
127 TypePool Types;
128
129 /// List of accelerator entries for this unit.
130 ArrayList<TypeUnitAccelInfo> AcceleratorRecords;
131
132 /// Guard for DebugStringIndexMap.
133 std::mutex DebugStringIndexMapMutex;
134};
135
136} // end of namespace parallel
137} // end of namespace dwarf_linker
138} // end of namespace llvm
139
140#endif // LLVM_DWARFLINKER_PARALLEL_DWARFLINKERTYPEUNIT_H
141