xref: /llvm-project/llvm/lib/Remarks/RemarkStringTable.cpp (revision 4287c95b08ab9b10cce50ab8139f536ea2d72f1d)
1 //===- RemarkStringTable.cpp ----------------------------------------------===//
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 // Implementation of the Remark string table used at remark generation.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "llvm/Remarks/RemarkStringTable.h"
14 #include "llvm/Remarks/RemarkParser.h"
15 #include "llvm/Support/EndianStream.h"
16 #include "llvm/Support/Error.h"
17 #include <vector>
18 
19 using namespace llvm;
20 using namespace llvm::remarks;
21 
22 StringTable::StringTable(const ParsedStringTable &Other) : StrTab() {
23   for (unsigned i = 0, e = Other.size(); i < e; ++i)
24     if (Expected<StringRef> MaybeStr = Other[i])
25       add(*MaybeStr);
26     else
27       llvm_unreachable("Unexpected error while building remarks string table.");
28 }
29 
30 std::pair<unsigned, StringRef> StringTable::add(StringRef Str) {
31   size_t NextID = StrTab.size();
32   auto KV = StrTab.insert({Str, NextID});
33   // If it's a new string, add it to the final size.
34   if (KV.second)
35     SerializedSize += KV.first->first().size() + 1; // +1 for the '\0'
36   // Can be either NextID or the previous ID if the string is already there.
37   return {KV.first->second, KV.first->first()};
38 }
39 
40 void StringTable::serialize(raw_ostream &OS) const {
41   // Emit the sequence of strings.
42   for (StringRef Str : serialize()) {
43     OS << Str;
44     // Explicitly emit a '\0'.
45     OS.write('\0');
46   }
47 }
48 
49 std::vector<StringRef> StringTable::serialize() const {
50   std::vector<StringRef> Strings{StrTab.size()};
51   for (const auto &KV : StrTab)
52     Strings[KV.second] = KV.first();
53   return Strings;
54 }
55