1//===- SymbolTable.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#include "SymbolTable.h"
10#include "InputFiles.h"
11#include "Symbols.h"
12#include "lld/Common/ErrorHandler.h"
13#include "lld/Common/Memory.h"
14
15using namespace llvm;
16using namespace lld;
17using namespace lld::macho;
18
19Symbol *SymbolTable::find(StringRef name) {
20  auto it = symMap.find(llvm::CachedHashStringRef(name));
21  if (it == symMap.end())
22    return nullptr;
23  return symVector[it->second];
24}
25
26std::pair<Symbol *, bool> SymbolTable::insert(StringRef name) {
27  auto p = symMap.insert({CachedHashStringRef(name), (int)symVector.size()});
28
29  // Name already present in the symbol table.
30  if (!p.second)
31    return {symVector[p.first->second], false};
32
33  // Name is a new symbol.
34  Symbol *sym = reinterpret_cast<Symbol *>(make<SymbolUnion>());
35  symVector.push_back(sym);
36  return {sym, true};
37}
38
39Symbol *SymbolTable::addDefined(StringRef name, InputSection *isec,
40                                uint32_t value) {
41  Symbol *s;
42  bool wasInserted;
43  std::tie(s, wasInserted) = insert(name);
44
45  if (!wasInserted && isa<Defined>(s))
46    error("duplicate symbol: " + name);
47
48  replaceSymbol<Defined>(s, name, isec, value);
49  return s;
50}
51
52Symbol *SymbolTable::addUndefined(StringRef name) {
53  Symbol *s;
54  bool wasInserted;
55  std::tie(s, wasInserted) = insert(name);
56
57  if (wasInserted)
58    replaceSymbol<Undefined>(s, name);
59  else if (LazySymbol *lazy = dyn_cast<LazySymbol>(s))
60    lazy->fetchArchiveMember();
61  return s;
62}
63
64Symbol *SymbolTable::addDylib(StringRef name, DylibFile *file) {
65  Symbol *s;
66  bool wasInserted;
67  std::tie(s, wasInserted) = insert(name);
68
69  if (wasInserted || isa<Undefined>(s))
70    replaceSymbol<DylibSymbol>(s, file, name);
71  return s;
72}
73
74Symbol *SymbolTable::addLazy(StringRef name, ArchiveFile *file,
75                             const llvm::object::Archive::Symbol &sym) {
76  Symbol *s;
77  bool wasInserted;
78  std::tie(s, wasInserted) = insert(name);
79
80  if (wasInserted)
81    replaceSymbol<LazySymbol>(s, file, sym);
82  else if (isa<Undefined>(s))
83    file->fetch(sym);
84  return s;
85}
86
87SymbolTable *macho::symtab;
88