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, bool is_override, bool* readonly) 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->ReadOnly()) { 68 if (readonly != nullptr) 69 *readonly = true; 70 else 71 ERROR("*** cannot assign to readonly variable: %s", c_str()); 72 return; 73 } else if (readonly != nullptr) { 74 *readonly = false; 75 } 76 if (!is_override && 77 (orig->Origin() == VarOrigin::OVERRIDE || 78 orig->Origin() == VarOrigin::ENVIRONMENT_OVERRIDE)) { 79 return; 80 } 81 if (orig->Origin() == VarOrigin::COMMAND_LINE && 82 v->Origin() == VarOrigin::FILE) { 83 return; 84 } 85 if (orig->Origin() == VarOrigin::AUTOMATIC) { 86 ERROR("overriding automatic variable is not implemented yet"); 87 } 88 if (orig->IsDefined()) 89 delete orig; 90 g_symbol_data[v_].gv = v; 91 } 92 93 ScopedGlobalVar::ScopedGlobalVar(Symbol name, Var* var) 94 : name_(name), orig_(NULL) { 95 orig_ = name.GetGlobalVar(); 96 g_symbol_data[name_.val()].gv = var; 97 } 98 99 ScopedGlobalVar::~ScopedGlobalVar() { 100 g_symbol_data[name_.val()].gv = orig_; 101 } 102 103 class Symtab { 104 public: 105 Symtab() { 106 #ifdef ENABLE_TID_CHECK 107 tid_ = pthread_self(); 108 #endif 109 110 CHECK(g_symbols == NULL); 111 g_symbols = &symbols_; 112 113 Symbol s = InternImpl(""); 114 CHECK(s.v_ == 0); 115 CHECK(Intern("") == s); 116 char b[2]; 117 b[1] = 0; 118 for (int i = 1; i < 256; i++) { 119 b[0] = i; 120 s = InternImpl(b); 121 CHECK(s.val() == i); 122 } 123 124 kEmptySym = Intern(""); 125 kShellSym = Intern("SHELL"); 126 } 127 128 ~Symtab() { 129 LOG_STAT("%zu symbols", symbols_.size()); 130 for (string* s : symbols_) 131 delete s; 132 } 133 134 Symbol InternImpl(StringPiece s) { 135 auto found = symtab_.find(s); 136 if (found != symtab_.end()) { 137 return found->second; 138 } 139 symbols_.push_back(new string(s.data(), s.size())); 140 Symbol sym = Symbol(symtab_.size()); 141 bool ok = symtab_.emplace(*symbols_.back(), sym).second; 142 CHECK(ok); 143 return sym; 144 } 145 146 Symbol Intern(StringPiece s) { 147 #ifdef ENABLE_TID_CHECK 148 if (tid_ != pthread_self()) 149 abort(); 150 #endif 151 152 if (s.size() <= 1) { 153 return Symbol(s.empty() ? 0 : (unsigned char)s[0]); 154 } 155 return InternImpl(s); 156 } 157 158 private: 159 unordered_map<StringPiece, Symbol> symtab_; 160 vector<string*> symbols_; 161 #ifdef ENABLE_TID_CHECK 162 pthread_t tid_; 163 #endif 164 }; 165 166 static Symtab* g_symtab; 167 168 void InitSymtab() { 169 g_symtab = new Symtab; 170 } 171 172 void QuitSymtab() { 173 delete g_symtab; 174 } 175 176 Symbol Intern(StringPiece s) { 177 return g_symtab->Intern(s); 178 } 179 180 string JoinSymbols(const vector<Symbol>& syms, const char* sep) { 181 vector<string> strs; 182 for (Symbol s : syms) { 183 strs.push_back(s.str()); 184 } 185 return JoinStrings(strs, sep); 186 } 187
