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() : gv(kUndefined) {} 34 35 Var* gv; 36 }; 37 38 vector<string*>* g_symbols; 39 static vector<SymbolData> g_symbol_data; 40 41 Symbol kEmptySym = Symbol(Symbol::IsUninitialized()); 42 Symbol kShellSym = Symbol(Symbol::IsUninitialized()); 43 44 Symbol::Symbol(int v) : v_(v) {} 45 46 Var* Symbol::PeekGlobalVar() const { 47 if (static_cast<size_t>(v_) >= g_symbol_data.size()) { 48 return kUndefined; 49 } 50 return g_symbol_data[v_].gv; 51 } 52 53 Var* Symbol::GetGlobalVar() const { 54 if (static_cast<size_t>(v_) >= g_symbol_data.size()) { 55 g_symbol_data.resize(v_ + 1); 56 } 57 Var* v = g_symbol_data[v_].gv; 58 if (v->Origin() == VarOrigin::ENVIRONMENT || 59 v->Origin() == VarOrigin::ENVIRONMENT_OVERRIDE) { 60 Vars::add_used_env_vars(*this); 61 } 62 return v; 63 } 64 65 void Symbol::SetGlobalVar(Var* v, bool is_override, bool* readonly) const { 66 if (static_cast<size_t>(v_) >= g_symbol_data.size()) { 67 g_symbol_data.resize(v_ + 1); 68 } 69 Var* orig = g_symbol_data[v_].gv; 70 if (orig->ReadOnly()) { 71 if (readonly != nullptr) 72 *readonly = true; 73 else 74 ERROR("*** cannot assign to readonly variable: %s", c_str()); 75 return; 76 } else if (readonly != nullptr) { 77 *readonly = false; 78 } 79 if (!is_override && (orig->Origin() == VarOrigin::OVERRIDE || 80 orig->Origin() == VarOrigin::ENVIRONMENT_OVERRIDE)) { 81 return; 82 } 83 if (orig->Origin() == VarOrigin::COMMAND_LINE && 84 v->Origin() == VarOrigin::FILE) { 85 return; 86 } 87 if (orig->Origin() == VarOrigin::AUTOMATIC) { 88 ERROR("overriding automatic variable is not implemented yet"); 89 } 90 if (orig->IsDefined()) 91 delete orig; 92 g_symbol_data[v_].gv = v; 93 } 94 95 ScopedGlobalVar::ScopedGlobalVar(Symbol name, Var* var) 96 : name_(name), orig_(NULL) { 97 orig_ = name.GetGlobalVar(); 98 g_symbol_data[name_.val()].gv = var; 99 } 100 101 ScopedGlobalVar::~ScopedGlobalVar() { 102 g_symbol_data[name_.val()].gv = orig_; 103 } 104 105 class Symtab { 106 public: 107 Symtab() { 108 #ifdef ENABLE_TID_CHECK 109 tid_ = pthread_self(); 110 #endif 111 112 CHECK(g_symbols == NULL); 113 g_symbols = &symbols_; 114 115 Symbol s = InternImpl(""); 116 CHECK(s.v_ == 0); 117 CHECK(Intern("") == s); 118 char b[2]; 119 b[1] = 0; 120 for (int i = 1; i < 256; i++) { 121 b[0] = i; 122 s = InternImpl(b); 123 CHECK(s.val() == i); 124 } 125 126 kEmptySym = Intern(""); 127 kShellSym = Intern("SHELL"); 128 } 129 130 ~Symtab() { 131 LOG_STAT("%zu symbols", symbols_.size()); 132 for (string* s : symbols_) 133 delete s; 134 } 135 136 Symbol InternImpl(StringPiece s) { 137 auto found = symtab_.find(s); 138 if (found != symtab_.end()) { 139 return found->second; 140 } 141 symbols_.push_back(new string(s.data(), s.size())); 142 Symbol sym = Symbol(symtab_.size()); 143 bool ok = symtab_.emplace(*symbols_.back(), sym).second; 144 CHECK(ok); 145 return sym; 146 } 147 148 Symbol Intern(StringPiece s) { 149 #ifdef ENABLE_TID_CHECK 150 if (tid_ != pthread_self()) 151 abort(); 152 #endif 153 154 if (s.size() <= 1) { 155 return Symbol(s.empty() ? 0 : (unsigned char)s[0]); 156 } 157 return InternImpl(s); 158 } 159 160 private: 161 unordered_map<StringPiece, Symbol> symtab_; 162 vector<string*> symbols_; 163 #ifdef ENABLE_TID_CHECK 164 pthread_t tid_; 165 #endif 166 }; 167 168 static Symtab* g_symtab; 169 170 void InitSymtab() { 171 g_symtab = new Symtab; 172 } 173 174 void QuitSymtab() { 175 delete g_symtab; 176 } 177 178 Symbol Intern(StringPiece s) { 179 return g_symtab->Intern(s); 180 } 181 182 string JoinSymbols(const vector<Symbol>& syms, const char* sep) { 183 vector<string> strs; 184 for (Symbol s : syms) { 185 strs.push_back(s.str()); 186 } 187 return JoinStrings(strs, sep); 188 } 189
