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 <algorithm>
16 #include <cassert>
17 #include <cstdint>
18 
19 using namespace llvm;
20 using namespace llvm::codeview;
21 
DebugStringTableSubsectionRef()22 DebugStringTableSubsectionRef::DebugStringTableSubsectionRef()
23     : DebugSubsectionRef(DebugSubsectionKind::StringTable) {}
24 
initialize(BinaryStreamRef Contents)25 Error DebugStringTableSubsectionRef::initialize(BinaryStreamRef Contents) {
26   Stream = Contents;
27   return Error::success();
28 }
29 
initialize(BinaryStreamReader & Reader)30 Error DebugStringTableSubsectionRef::initialize(BinaryStreamReader &Reader) {
31   return Reader.readStreamRef(Stream);
32 }
33 
34 Expected<StringRef>
getString(uint32_t Offset) const35 DebugStringTableSubsectionRef::getString(uint32_t Offset) const {
36   BinaryStreamReader Reader(Stream);
37   Reader.setOffset(Offset);
38   StringRef Result;
39   if (auto EC = Reader.readCString(Result))
40     return std::move(EC);
41   return Result;
42 }
43 
DebugStringTableSubsection()44 DebugStringTableSubsection::DebugStringTableSubsection()
45     : DebugSubsection(DebugSubsectionKind::StringTable) {}
46 
insert(StringRef S)47 uint32_t DebugStringTableSubsection::insert(StringRef S) {
48   auto P = StringToId.insert({S, StringSize});
49 
50   // If a given string didn't exist in the string table, we want to increment
51   // the string table size and insert it into the reverse lookup.
52   if (P.second) {
53     IdToString.insert({P.first->getValue(), P.first->getKey()});
54     StringSize += S.size() + 1; // +1 for '\0'
55   }
56 
57   return P.first->second;
58 }
59 
calculateSerializedSize() const60 uint32_t DebugStringTableSubsection::calculateSerializedSize() const {
61   return StringSize;
62 }
63 
commit(BinaryStreamWriter & Writer) const64 Error DebugStringTableSubsection::commit(BinaryStreamWriter &Writer) const {
65   uint32_t Begin = Writer.getOffset();
66   uint32_t End = Begin + StringSize;
67 
68   // Write a null string at the beginning.
69   if (auto EC = Writer.writeCString(StringRef()))
70     return EC;
71 
72   for (auto &Pair : StringToId) {
73     StringRef S = Pair.getKey();
74     uint32_t Offset = Begin + Pair.getValue();
75     Writer.setOffset(Offset);
76     if (auto EC = Writer.writeCString(S))
77       return EC;
78     assert(Writer.getOffset() <= End);
79   }
80 
81   Writer.setOffset(End);
82   assert((End - Begin) == StringSize);
83   return Error::success();
84 }
85 
size() const86 uint32_t DebugStringTableSubsection::size() const { return StringToId.size(); }
87 
sortedIds() const88 std::vector<uint32_t> DebugStringTableSubsection::sortedIds() const {
89   std::vector<uint32_t> Result;
90   Result.reserve(IdToString.size());
91   for (const auto &Entry : IdToString)
92     Result.push_back(Entry.first);
93   llvm::sort(Result);
94   return Result;
95 }
96 
getIdForString(StringRef S) const97 uint32_t DebugStringTableSubsection::getIdForString(StringRef S) const {
98   auto Iter = StringToId.find(S);
99   assert(Iter != StringToId.end());
100   return Iter->second;
101 }
102 
getStringForId(uint32_t Id) const103 StringRef DebugStringTableSubsection::getStringForId(uint32_t Id) const {
104   auto Iter = IdToString.find(Id);
105   assert(Iter != IdToString.end());
106   return Iter->second;
107 }
108