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(Var::Undefined()) {} 34 35 Var* gv; 36 }; 37 38 vector<string*>* g_symbols; 39 static vector<SymbolData> g_symbol_data; 40 41 Symbol kEmptySym; 42 Symbol kShellSym; 43 Symbol kKatiReadonlySym; 44 45 Symbol::Symbol(int v) : v_(v) {} 46 47 Var* Symbol::PeekGlobalVar() const { 48 if (static_cast<size_t>(v_) >= g_symbol_data.size()) { 49 return Var::Undefined(); 50 } 51 return g_symbol_data[v_].gv; 52 } 53 54 Var* Symbol::GetGlobalVar() const { 55 if (static_cast<size_t>(v_) >= g_symbol_data.size()) { 56 g_symbol_data.resize(v_ + 1); 57 } 58 Var* v = g_symbol_data[v_].gv; 59 if (v->Origin() == VarOrigin::ENVIRONMENT || 60 v->Origin() == VarOrigin::ENVIRONMENT_OVERRIDE) { 61 Vars::add_used_env_vars(*this); 62 } 63 return v; 64 } 65 66 void Symbol::SetGlobalVar(Var* v, bool is_override, bool* readonly) const { 67 if (static_cast<size_t>(v_) >= g_symbol_data.size()) { 68 g_symbol_data.resize(v_ + 1); 69 } 70 Var* orig = g_symbol_data[v_].gv; 71 if (orig->ReadOnly()) { 72 if (readonly != nullptr) 73 *readonly = true; 74 else 75 ERROR("*** cannot assign to readonly variable: %s", c_str()); 76 return; 77 } else if (readonly != nullptr) { 78 *readonly = false; 79 } 80 if (!is_override && (orig->Origin() == VarOrigin::OVERRIDE || 81 orig->Origin() == VarOrigin::ENVIRONMENT_OVERRIDE)) { 82 return; 83 } 84 if (orig->Origin() == VarOrigin::COMMAND_LINE && 85 v->Origin() == VarOrigin::FILE) { 86 return; 87 } 88 if (orig->Origin() == VarOrigin::AUTOMATIC) { 89 ERROR("overriding automatic variable is not implemented yet"); 90 } 91 if (orig->IsDefined()) 92 delete orig; 93 g_symbol_data[v_].gv = v; 94 } 95 96 ScopedGlobalVar::ScopedGlobalVar(Symbol name, Var* var) 97 : name_(name), orig_(NULL) { 98 orig_ = name.GetGlobalVar(); 99 g_symbol_data[name_.val()].gv = var; 100 } 101 102 ScopedGlobalVar::~ScopedGlobalVar() { 103 g_symbol_data[name_.val()].gv = orig_; 104 } 105 106 class Symtab { 107 public: 108 Symtab() { 109 #ifdef ENABLE_TID_CHECK 110 tid_ = pthread_self(); 111 #endif 112 113 CHECK(g_symbols == NULL); 114 g_symbols = &symbols_; 115 116 Symbol s = InternImpl(""); 117 CHECK(s.v_ == 0); 118 CHECK(Intern("") == s); 119 char b[2]; 120 b[1] = 0; 121 for (int i = 1; i < 256; i++) { 122 b[0] = i; 123 s = InternImpl(b); 124 CHECK(s.val() == i); 125 } 126 127 kEmptySym = Intern(""); 128 kShellSym = Intern("SHELL"); 129 kKatiReadonlySym = Intern(".KATI_READONLY"); 130 } 131 132 ~Symtab() { 133 LOG_STAT("%zu symbols", symbols_.size()); 134 for (string* s : symbols_) 135 delete s; 136 } 137 138 Symbol InternImpl(StringPiece s) { 139 auto found = symtab_.find(s); 140 if (found != symtab_.end()) { 141 return found->second; 142 } 143 symbols_.push_back(new string(s.data(), s.size())); 144 Symbol sym = Symbol(symtab_.size()); 145 bool ok = symtab_.emplace(*symbols_.back(), sym).second; 146 CHECK(ok); 147 return sym; 148 } 149 150 Symbol Intern(StringPiece s) { 151 #ifdef ENABLE_TID_CHECK 152 if (tid_ != pthread_self()) 153 abort(); 154 #endif 155 156 if (s.size() <= 1) { 157 return Symbol(s.empty() ? 0 : (unsigned char)s[0]); 158 } 159 return InternImpl(s); 160 } 161 162 private: 163 unordered_map<StringPiece, Symbol> symtab_; 164 vector<string*> symbols_; 165 #ifdef ENABLE_TID_CHECK 166 pthread_t tid_; 167 #endif 168 }; 169 170 static Symtab* g_symtab; 171 172 void InitSymtab() { 173 g_symtab = new Symtab; 174 } 175 176 void QuitSymtab() { 177 delete g_symtab; 178 } 179 180 Symbol Intern(StringPiece s) { 181 return g_symtab->Intern(s); 182 } 183 184 string JoinSymbols(const vector<Symbol>& syms, const char* sep) { 185 vector<string> strs; 186 for (Symbol s : syms) { 187 strs.push_back(s.str()); 188 } 189 return JoinStrings(strs, sep); 190 } 191
