xref: /llvm-project/llvm/lib/DebugInfo/CodeView/DebugStringTableSubsection.cpp (revision 0060c54e0da6d1429875da2d30895faa7562b706)
1 //===- DebugStringTableSubsection.cpp - CodeView String Table -------------===//
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 #include "llvm/DebugInfo/CodeView/DebugStringTableSubsection.h"
10 #include "llvm/ADT/StringRef.h"
11 #include "llvm/DebugInfo/CodeView/CodeView.h"
12 #include "llvm/Support/BinaryStreamReader.h"
13 #include "llvm/Support/BinaryStreamWriter.h"
14 #include "llvm/Support/Error.h"
15 #include <cassert>
16 #include <cstdint>
17 
18 using namespace llvm;
19 using namespace llvm::codeview;
20 
21 DebugStringTableSubsectionRef::DebugStringTableSubsectionRef()
22     : DebugSubsectionRef(DebugSubsectionKind::StringTable) {}
23 
24 Error DebugStringTableSubsectionRef::initialize(BinaryStreamRef Contents) {
25   Stream = Contents;
26   return Error::success();
27 }
28 
29 Error DebugStringTableSubsectionRef::initialize(BinaryStreamReader &Reader) {
30   return Reader.readStreamRef(Stream);
31 }
32 
33 Expected<StringRef>
34 DebugStringTableSubsectionRef::getString(uint32_t Offset) const {
35   BinaryStreamReader Reader(Stream);
36   Reader.setOffset(Offset);
37   StringRef Result;
38   if (auto EC = Reader.readCString(Result))
39     return std::move(EC);
40   return Result;
41 }
42 
43 DebugStringTableSubsection::DebugStringTableSubsection()
44     : DebugSubsection(DebugSubsectionKind::StringTable) {}
45 
46 uint32_t DebugStringTableSubsection::insert(StringRef S) {
47   auto P = StringToId.insert({S, StringSize});
48 
49   // If a given string didn't exist in the string table, we want to increment
50   // the string table size and insert it into the reverse lookup.
51   if (P.second) {
52     IdToString.insert({P.first->getValue(), P.first->getKey()});
53     StringSize += S.size() + 1; // +1 for '\0'
54   }
55 
56   return P.first->second;
57 }
58 
59 uint32_t DebugStringTableSubsection::calculateSerializedSize() const {
60   return StringSize;
61 }
62 
63 Error DebugStringTableSubsection::commit(BinaryStreamWriter &Writer) const {
64   uint32_t Begin = Writer.getOffset();
65   uint32_t End = Begin + StringSize;
66 
67   // Write a null string at the beginning.
68   if (auto EC = Writer.writeCString(StringRef()))
69     return EC;
70 
71   for (auto &Pair : StringToId) {
72     StringRef S = Pair.getKey();
73     uint32_t Offset = Begin + Pair.getValue();
74     Writer.setOffset(Offset);
75     if (auto EC = Writer.writeCString(S))
76       return EC;
77     assert(Writer.getOffset() <= End);
78   }
79 
80   Writer.setOffset(End);
81   assert((End - Begin) == StringSize);
82   return Error::success();
83 }
84 
85 uint32_t DebugStringTableSubsection::size() const { return StringToId.size(); }
86 
87 std::vector<uint32_t> DebugStringTableSubsection::sortedIds() const {
88   std::vector<uint32_t> Result;
89   Result.reserve(IdToString.size());
90   for (const auto &Entry : IdToString)
91     Result.push_back(Entry.first);
92   llvm::sort(Result);
93   return Result;
94 }
95 
96 uint32_t DebugStringTableSubsection::getIdForString(StringRef S) const {
97   auto Iter = StringToId.find(S);
98   assert(Iter != StringToId.end());
99   return Iter->second;
100 }
101 
102 StringRef DebugStringTableSubsection::getStringForId(uint32_t Id) const {
103   auto Iter = IdToString.find(Id);
104   assert(Iter != IdToString.end());
105   return Iter->second;
106 }
107