1 //===- DebugStringTableSubsection.cpp - CodeView String Table -------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/DebugInfo/CodeView/DebugStringTableSubsection.h"
11 #include "llvm/ADT/StringRef.h"
12 #include "llvm/DebugInfo/CodeView/CodeView.h"
13 #include "llvm/Support/BinaryStreamReader.h"
14 #include "llvm/Support/BinaryStreamWriter.h"
15 #include "llvm/Support/Error.h"
16 #include <algorithm>
17 #include <cassert>
18 #include <cstdint>
19 
20 using namespace llvm;
21 using namespace llvm::codeview;
22 
23 DebugStringTableSubsectionRef::DebugStringTableSubsectionRef()
24     : DebugSubsectionRef(DebugSubsectionKind::StringTable) {}
25 
26 Error DebugStringTableSubsectionRef::initialize(BinaryStreamRef Contents) {
27   Stream = Contents;
28   return Error::success();
29 }
30 
31 Error DebugStringTableSubsectionRef::initialize(BinaryStreamReader &Reader) {
32   return Reader.readStreamRef(Stream);
33 }
34 
35 Expected<StringRef>
36 DebugStringTableSubsectionRef::getString(uint32_t Offset) const {
37   BinaryStreamReader Reader(Stream);
38   Reader.setOffset(Offset);
39   StringRef Result;
40   if (auto EC = Reader.readCString(Result))
41     return std::move(EC);
42   return Result;
43 }
44 
45 DebugStringTableSubsection::DebugStringTableSubsection()
46     : DebugSubsection(DebugSubsectionKind::StringTable) {}
47 
48 uint32_t DebugStringTableSubsection::insert(StringRef S) {
49   auto P = Strings.insert({S, StringSize});
50 
51   // If a given string didn't exist in the string table, we want to increment
52   // the string table size.
53   if (P.second)
54     StringSize += S.size() + 1; // +1 for '\0'
55   return P.first->second;
56 }
57 
58 uint32_t DebugStringTableSubsection::calculateSerializedSize() const {
59   return StringSize;
60 }
61 
62 Error DebugStringTableSubsection::commit(BinaryStreamWriter &Writer) const {
63   uint32_t Begin = Writer.getOffset();
64   uint32_t End = Begin + StringSize;
65 
66   // Write a null string at the beginning.
67   if (auto EC = Writer.writeCString(StringRef()))
68     return EC;
69 
70   for (auto &Pair : Strings) {
71     StringRef S = Pair.getKey();
72     uint32_t Offset = Begin + Pair.getValue();
73     Writer.setOffset(Offset);
74     if (auto EC = Writer.writeCString(S))
75       return EC;
76     assert(Writer.getOffset() <= End);
77   }
78 
79   Writer.setOffset(End);
80   assert((End - Begin) == StringSize);
81   return Error::success();
82 }
83 
84 uint32_t DebugStringTableSubsection::size() const { return Strings.size(); }
85 
86 uint32_t DebugStringTableSubsection::getStringId(StringRef S) const {
87   auto Iter = Strings.find(S);
88   assert(Iter != Strings.end());
89   return Iter->second;
90 }
91