1 //===--- lib/CodeGen/DebugLocStream.h - DWARF debug_loc stream --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGLOCSTREAM_H
11 #define LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGLOCSTREAM_H
13 #include "llvm/ADT/ArrayRef.h"
14 #include "llvm/ADT/SmallVector.h"
15 #include "ByteStreamer.h"
21 class DwarfCompileUnit;
25 /// \brief Byte stream of .debug_loc entries.
27 /// Stores a unified stream of .debug_loc entries. There's \a List for each
28 /// variable/inlined-at pair, and an \a Entry for each \a DebugLocEntry.
30 /// FIXME: Do we need all these temp symbols?
31 /// FIXME: Why not output directly to the output stream?
32 class DebugLocStream {
36 MCSymbol *Label = nullptr;
38 List(DwarfCompileUnit *CU, size_t EntryOffset)
39 : CU(CU), EntryOffset(EntryOffset) {}
42 const MCSymbol *BeginSym;
43 const MCSymbol *EndSym;
46 Entry(const MCSymbol *BeginSym, const MCSymbol *EndSym, size_t ByteOffset,
48 : BeginSym(BeginSym), EndSym(EndSym), ByteOffset(ByteOffset),
49 CommentOffset(CommentOffset) {}
53 SmallVector<List, 4> Lists;
54 SmallVector<Entry, 32> Entries;
55 SmallString<256> DWARFBytes;
56 SmallVector<std::string, 32> Comments;
58 /// \brief Only verbose textual output needs comments. This will be set to
59 /// true for that case, and false otherwise.
60 bool GenerateComments;
63 DebugLocStream(bool GenerateComments) : GenerateComments(GenerateComments) { }
64 size_t getNumLists() const { return Lists.size(); }
65 const List &getList(size_t LI) const { return Lists[LI]; }
66 ArrayRef<List> getLists() const { return Lists; }
72 /// \brief Start a new .debug_loc entry list.
74 /// Start a new .debug_loc entry list. Return the new list's index so it can
75 /// be retrieved later via \a getList().
77 /// Until the next call, \a startEntry() will add entries to this list.
78 size_t startList(DwarfCompileUnit *CU) {
79 size_t LI = Lists.size();
80 Lists.emplace_back(CU, Entries.size());
84 /// Finalize a .debug_loc entry list.
86 /// If there are no entries in this list, delete it outright. Otherwise,
87 /// create a label with \a Asm.
89 /// \return false iff the list is deleted.
90 bool finalizeList(AsmPrinter &Asm);
92 /// \brief Start a new .debug_loc entry.
94 /// Until the next call, bytes added to the stream will be added to this
96 void startEntry(const MCSymbol *BeginSym, const MCSymbol *EndSym) {
97 Entries.emplace_back(BeginSym, EndSym, DWARFBytes.size(), Comments.size());
100 /// Finalize a .debug_loc entry, deleting if it's empty.
101 void finalizeEntry();
104 BufferByteStreamer getStreamer() {
105 return BufferByteStreamer(DWARFBytes, Comments, GenerateComments);
108 ArrayRef<Entry> getEntries(const List &L) const {
109 size_t LI = getIndex(L);
110 return makeArrayRef(Entries)
111 .slice(Lists[LI].EntryOffset, getNumEntries(LI));
114 ArrayRef<char> getBytes(const Entry &E) const {
115 size_t EI = getIndex(E);
116 return makeArrayRef(DWARFBytes.begin(), DWARFBytes.end())
117 .slice(Entries[EI].ByteOffset, getNumBytes(EI));
119 ArrayRef<std::string> getComments(const Entry &E) const {
120 size_t EI = getIndex(E);
121 return makeArrayRef(Comments)
122 .slice(Entries[EI].CommentOffset, getNumComments(EI));
126 size_t getIndex(const List &L) const {
127 assert(&Lists.front() <= &L && &L <= &Lists.back() &&
128 "Expected valid list");
129 return &L - &Lists.front();
131 size_t getIndex(const Entry &E) const {
132 assert(&Entries.front() <= &E && &E <= &Entries.back() &&
133 "Expected valid entry");
134 return &E - &Entries.front();
136 size_t getNumEntries(size_t LI) const {
137 if (LI + 1 == Lists.size())
138 return Entries.size() - Lists[LI].EntryOffset;
139 return Lists[LI + 1].EntryOffset - Lists[LI].EntryOffset;
141 size_t getNumBytes(size_t EI) const {
142 if (EI + 1 == Entries.size())
143 return DWARFBytes.size() - Entries[EI].ByteOffset;
144 return Entries[EI + 1].ByteOffset - Entries[EI].ByteOffset;
146 size_t getNumComments(size_t EI) const {
147 if (EI + 1 == Entries.size())
148 return Comments.size() - Entries[EI].CommentOffset;
149 return Entries[EI + 1].CommentOffset - Entries[EI].CommentOffset;
153 /// Builder for DebugLocStream lists.
154 class DebugLocStream::ListBuilder {
155 DebugLocStream &Locs;
158 const MachineInstr &MI;
162 ListBuilder(DebugLocStream &Locs, DwarfCompileUnit &CU, AsmPrinter &Asm,
163 DbgVariable &V, const MachineInstr &MI)
164 : Locs(Locs), Asm(Asm), V(V), MI(MI), ListIndex(Locs.startList(&CU)) {}
166 /// Finalize the list.
168 /// If the list is empty, delete it. Otherwise, finalize it by creating a
169 /// temp symbol in \a Asm and setting up the \a DbgVariable.
172 DebugLocStream &getLocs() { return Locs; }
175 /// Builder for DebugLocStream entries.
176 class DebugLocStream::EntryBuilder {
177 DebugLocStream &Locs;
180 EntryBuilder(ListBuilder &List, const MCSymbol *Begin, const MCSymbol *End)
181 : Locs(List.getLocs()) {
182 Locs.startEntry(Begin, End);
185 /// Finalize the entry, deleting it if it's empty.
186 ~EntryBuilder() { Locs.finalizeEntry(); }
188 BufferByteStreamer getStreamer() { return Locs.getStreamer(); }