1 // Copyright 2015 Google Inc. All rights reserved 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 // +build ignore 16 17 //#define ENABLE_TID_CHECK 18 19 #include "symtab.h" 20 21 #ifdef ENABLE_TID_CHECK 22 #include <pthread.h> 23 #endif 24 #include <string.h> 25 26 #include <unordered_map> 27 28 #include "log.h" 29 #include "strutil.h" 30 #include "var.h" 31 32 struct SymbolData { 33 SymbolData() 34 : gv(kUndefined) { 35 } 36 37 Var* gv; 38 }; 39 40 vector<string*>* g_symbols; 41 static vector<SymbolData> g_symbol_data; 42 43 Symbol kEmptySym = Symbol(Symbol::IsUninitialized()); 44 Symbol kShellSym = Symbol(Symbol::IsUninitialized()); 45 46 Symbol::Symbol(int v) 47 : v_(v) { 48 } 49 50 Var* Symbol::GetGlobalVar() const { 51 if (static_cast<size_t>(v_) >= g_symbol_data.size()) { 52 g_symbol_data.resize(v_ + 1); 53 } 54 Var* v = g_symbol_data[v_].gv; 55 if (v->Origin() == VarOrigin::ENVIRONMENT || 56 v->Origin() == VarOrigin::ENVIRONMENT_OVERRIDE) { 57 Vars::add_used_env_vars(*this); 58 } 59 return v; 60 } 61 62 void Symbol::SetGlobalVar(Var* v) const { 63 if (static_cast<size_t>(v_) >= g_symbol_data.size()) { 64 g_symbol_data.resize(v_ + 1); 65 } 66 Var* orig = g_symbol_data[v_].gv; 67 if (orig->Origin() == VarOrigin::OVERRIDE || 68 orig->Origin() == VarOrigin::ENVIRONMENT_OVERRIDE) { 69 return; 70 } 71 if (orig->Origin() == VarOrigin::AUTOMATIC) { 72 ERROR("overriding automatic variable is not implemented yet"); 73 } 74 if (orig->IsDefined()) 75 delete orig; 76 g_symbol_data[v_].gv = v; 77 } 78 79 ScopedGlobalVar::ScopedGlobalVar(Symbol name, Var* var) 80 : name_(name), orig_(NULL) { 81 orig_ = name.GetGlobalVar(); 82 g_symbol_data[name_.val()].gv = var; 83 } 84 85 ScopedGlobalVar::~ScopedGlobalVar() { 86 g_symbol_data[name_.val()].gv = orig_; 87 } 88 89 class Symtab { 90 public: 91 Symtab() { 92 #ifdef ENABLE_TID_CHECK 93 tid_ = pthread_self(); 94 #endif 95 96 CHECK(g_symbols == NULL); 97 g_symbols = &symbols_; 98 99 Symbol s = InternImpl(""); 100 CHECK(s.v_ == 0); 101 CHECK(Intern("") == s); 102 char b[2]; 103 b[1] = 0; 104 for (int i = 1; i < 256; i++) { 105 b[0] = i; 106 s = InternImpl(b); 107 CHECK(s.val() == i); 108 } 109 110 kEmptySym = Intern(""); 111 kShellSym = Intern("SHELL"); 112 } 113 114 ~Symtab() { 115 LOG_STAT("%zu symbols", symbols_.size()); 116 for (string* s : symbols_) 117 delete s; 118 } 119 120 Symbol InternImpl(StringPiece s) { 121 auto found = symtab_.find(s); 122 if (found != symtab_.end()) { 123 return found->second; 124 } 125 symbols_.push_back(new string(s.data(), s.size())); 126 Symbol sym = Symbol(symtab_.size()); 127 bool ok = symtab_.emplace(*symbols_.back(), sym).second; 128 CHECK(ok); 129 return sym; 130 } 131 132 Symbol Intern(StringPiece s) { 133 #ifdef ENABLE_TID_CHECK 134 if (tid_ != pthread_self()) 135 abort(); 136 #endif 137 138 if (s.size() <= 1) { 139 return Symbol(s.empty() ? 0 : (unsigned char)s[0]); 140 } 141 return InternImpl(s); 142 } 143 144 private: 145 unordered_map<StringPiece, Symbol> symtab_; 146 vector<string*> symbols_; 147 #ifdef ENABLE_TID_CHECK 148 pthread_t tid_; 149 #endif 150 }; 151 152 static Symtab* g_symtab; 153 154 void InitSymtab() { 155 g_symtab = new Symtab; 156 } 157 158 void QuitSymtab() { 159 delete g_symtab; 160 } 161 162 Symbol Intern(StringPiece s) { 163 return g_symtab->Intern(s); 164 } 165 166 string JoinSymbols(const vector<Symbol>& syms, const char* sep) { 167 vector<string> strs; 168 for (Symbol s : syms) { 169 strs.push_back(s.str()); 170 } 171 return JoinStrings(strs, sep); 172 } 173
