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| 1 // Copyright (c) 2013 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #ifndef TOOLS_GN_SCOPE_H_ | |
| 6 #define TOOLS_GN_SCOPE_H_ | |
| 7 | |
| 8 #include <map> | |
| 9 #include <set> | |
| 10 | |
| 11 #include "base/basictypes.h" | |
| 12 #include "base/containers/hash_tables.h" | |
| 13 #include "base/memory/scoped_ptr.h" | |
| 14 #include "tools/gn/err.h" | |
| 15 #include "tools/gn/pattern.h" | |
| 16 #include "tools/gn/value.h" | |
| 17 | |
| 18 class FunctionCallNode; | |
| 19 class ImportManager; | |
| 20 class ParseNode; | |
| 21 class Settings; | |
| 22 class TargetManager; | |
| 23 | |
| 24 // Scope for the script execution. | |
| 25 // | |
| 26 // Scopes are nested. Writing goes into the toplevel scope, reading checks | |
| 27 // values resursively down the stack until a match is found or there are no | |
| 28 // more containing scopes. | |
| 29 // | |
| 30 // A containing scope can be const or non-const. The const containing scope is | |
| 31 // used primarily to refer to the master build config which is shared across | |
| 32 // many invocations. A const containing scope, however, prevents us from | |
| 33 // marking variables "used" which prevents us from issuing errors on unused | |
| 34 // variables. So you should use a non-const containing scope whenever possible. | |
| 35 class Scope { | |
| 36 public: | |
| 37 typedef std::vector<std::pair<base::StringPiece, Value> > KeyValueVector; | |
| 38 | |
| 39 // Allows code to provide values for built-in variables. This class will | |
| 40 // automatically register itself on construction and deregister itself on | |
| 41 // destruction. | |
| 42 class ProgrammaticProvider { | |
| 43 public: | |
| 44 ProgrammaticProvider(Scope* scope) : scope_(scope) { | |
| 45 scope_->AddProvider(this); | |
| 46 } | |
| 47 ~ProgrammaticProvider() { | |
| 48 scope_->RemoveProvider(this); | |
| 49 } | |
| 50 | |
| 51 // Returns a non-null value if the given value can be programmatically | |
| 52 // generated, or NULL if there is none. | |
| 53 virtual const Value* GetProgrammaticValue( | |
| 54 const base::StringPiece& ident) = 0; | |
| 55 | |
| 56 protected: | |
| 57 Scope* scope_; | |
| 58 }; | |
| 59 | |
| 60 // Creates an empty toplevel scope. | |
| 61 Scope(const Settings* settings); | |
| 62 | |
| 63 // Creates a dependent scope. | |
| 64 Scope(Scope* parent); | |
| 65 Scope(const Scope* parent); | |
| 66 | |
| 67 ~Scope(); | |
| 68 | |
| 69 const Settings* settings() const { return settings_; } | |
| 70 | |
| 71 // See the const_/mutable_containing_ var declaraions below. Yes, it's a | |
| 72 // bit weird that we can have a const pointer to the "mutable" one. | |
| 73 Scope* mutable_containing() { return mutable_containing_; } | |
| 74 const Scope* mutable_containing() const { return mutable_containing_; } | |
| 75 const Scope* const_containing() const { return const_containing_; } | |
| 76 const Scope* containing() const { | |
| 77 return mutable_containing_ ? mutable_containing_ : const_containing_; | |
| 78 } | |
| 79 | |
| 80 // Returns NULL if there's no such value. | |
| 81 // | |
| 82 // counts_as_used should be set if the variable is being read in a way that | |
| 83 // should count for unused variable checking. | |
| 84 const Value* GetValue(const base::StringPiece& ident, | |
| 85 bool counts_as_used); | |
| 86 const Value* GetValue(const base::StringPiece& ident) const; | |
| 87 | |
| 88 // Same as GetValue, but if the value exists in a parent scope, we'll copy | |
| 89 // it to the current scope. If the return value is non-null, the value is | |
| 90 // guaranteed to be set in the current scope. Generatlly this will be used | |
| 91 // if the calling code is planning on modifying the value in-place. | |
| 92 // | |
| 93 // Since this is used when doing read-modifies, we never count this access | |
| 94 // as reading the variable, since we assume it will be written to. | |
| 95 Value* GetValueForcedToCurrentScope(const base::StringPiece& ident, | |
| 96 const ParseNode* set_node); | |
| 97 | |
| 98 // The set_node indicates the statement that caused the set, for displaying | |
| 99 // errors later. Returns a pointer to the value in the current scope (a copy | |
| 100 // is made for storage). | |
| 101 Value* SetValue(const base::StringPiece& ident, | |
| 102 const Value& v, | |
| 103 const ParseNode* set_node); | |
| 104 | |
| 105 // Templates associated with this scope. A template can only be set once, so | |
| 106 // AddTemplate will fail and return NULL if a rule with that name already | |
| 107 // exists. GetTemplate returns NULL if the rule doesn't exist, and it will | |
| 108 // check all containing scoped rescursively. | |
| 109 bool AddTemplate(const std::string& name, const FunctionCallNode* decl); | |
| 110 const FunctionCallNode* GetTemplate(const std::string& name) const; | |
| 111 | |
| 112 // Marks the given identifier as (un)used in the current scope. | |
| 113 void MarkUsed(const base::StringPiece& ident); | |
| 114 void MarkUnused(const base::StringPiece& ident); | |
| 115 | |
| 116 // Checks to see if the scope has a var set that hasn't been used. This is | |
| 117 // called before replacing the var with a different one. It does not check | |
| 118 // containing scopes. | |
| 119 // | |
| 120 // If the identifier is present but hasnn't been used, return true. | |
| 121 bool IsSetButUnused(const base::StringPiece& ident) const; | |
| 122 | |
| 123 // Checks the scope to see if any values were set but not used, and fills in | |
| 124 // the error and returns false if they were. | |
| 125 bool CheckForUnusedVars(Err* err) const; | |
| 126 | |
| 127 // Returns all values set in the current scope, without going to the parent | |
| 128 // scopes. | |
| 129 void GetCurrentScopeValues(KeyValueVector* output) const; | |
| 130 | |
| 131 // Copies this scope's values into the destination. Values from the | |
| 132 // containing scope(s) (normally shadowed into the current one) will not be | |
| 133 // copied, neither will the reference to the containing scope (this is why | |
| 134 // it's "non-recursive"). | |
| 135 // | |
| 136 // It is an error to merge a variable into a scope that already has something | |
| 137 // with that name in scope (meaning in that scope or in any of its containing | |
| 138 // scopes). If this happens, the error will be set and the function will | |
| 139 // return false. | |
| 140 // | |
| 141 // This is used in different contexts. When generating the error, the given | |
| 142 // parse node will be blamed, and the given desc will be used to describe | |
| 143 // the operation that doesn't support doing this. For example, desc_for_err | |
| 144 // would be "import" when doing an import, and the error string would say | |
| 145 // something like "The import contains...". | |
| 146 bool NonRecursiveMergeTo(Scope* dest, | |
| 147 const ParseNode* node_for_err, | |
| 148 const char* desc_for_err, | |
| 149 Err* err) const; | |
| 150 | |
| 151 // Makes an empty scope with the given name. Returns NULL if the name is | |
| 152 // already set. | |
| 153 Scope* MakeTargetDefaults(const std::string& target_type); | |
| 154 | |
| 155 // Gets the scope associated with the given target name, or null if it hasn't | |
| 156 // been set. | |
| 157 const Scope* GetTargetDefaults(const std::string& target_type) const; | |
| 158 | |
| 159 // Filter to apply when the sources variable is assigned. May return NULL. | |
| 160 const PatternList* GetSourcesAssignmentFilter() const; | |
| 161 void set_sources_assignment_filter( | |
| 162 scoped_ptr<PatternList> f) { | |
| 163 sources_assignment_filter_ = f.Pass(); | |
| 164 } | |
| 165 | |
| 166 // Indicates if we're currently processing the build configuration file. | |
| 167 // This is true when processing the config file for any toolchain. See also | |
| 168 // *ProcessingDefaultBuildConfig() below. | |
| 169 // | |
| 170 // To set or clear the flag, it must currently be in the opposite state in | |
| 171 // the current scope. Note that querying the state of the flag recursively | |
| 172 // checks all containing scopes until it reaches the top or finds the flag | |
| 173 // set. | |
| 174 void SetProcessingBuildConfig(); | |
| 175 void ClearProcessingBuildConfig(); | |
| 176 bool IsProcessingBuildConfig() const; | |
| 177 | |
| 178 // Indicates we're currently processing the default toolchain's build | |
| 179 // configuration file. | |
| 180 void SetProcessingDefaultBuildConfig(); | |
| 181 void ClearProcessingDefaultBuildConfig(); | |
| 182 bool IsProcessingDefaultBuildConfig() const; | |
| 183 | |
| 184 // Indicates if we're currently processing an import file. | |
| 185 // | |
| 186 // See SetProcessingBaseConfig for how flags work. | |
| 187 void SetProcessingImport(); | |
| 188 void ClearProcessingImport(); | |
| 189 bool IsProcessingImport() const; | |
| 190 | |
| 191 // Properties are opaque pointers that code can use to set state on a Scope | |
| 192 // that it can retrieve later. | |
| 193 // | |
| 194 // The key should be a pointer to some use-case-specific object (to avoid | |
| 195 // collisions, otherwise it doesn't matter). Memory management is up to the | |
| 196 // setter. Setting the value to NULL will delete the property. | |
| 197 // | |
| 198 // Getting a property recursively searches all scopes, and the optional | |
| 199 // |found_on_scope| variable will be filled with the actual scope containing | |
| 200 // the key (if the pointer is non-NULL). | |
| 201 void SetProperty(const void* key, void* value); | |
| 202 void* GetProperty(const void* key, const Scope** found_on_scope) const; | |
| 203 | |
| 204 private: | |
| 205 friend class ProgrammaticProvider; | |
| 206 | |
| 207 struct Record { | |
| 208 Record() : used(false) {} | |
| 209 Record(const Value& v) : used(false), value(v) {} | |
| 210 | |
| 211 bool used; // Set to true when the variable is used. | |
| 212 Value value; | |
| 213 }; | |
| 214 | |
| 215 void AddProvider(ProgrammaticProvider* p); | |
| 216 void RemoveProvider(ProgrammaticProvider* p); | |
| 217 | |
| 218 // Scopes can have no containing scope (both null), a mutable containing | |
| 219 // scope, or a const containing scope. The reason is that when we're doing | |
| 220 // a new target, we want to refer to the base_config scope which will be read | |
| 221 // by multiple threads at the same time, so we REALLY want it to be const. | |
| 222 // When you jsut do a nested {}, however, we sometimes want to be able to | |
| 223 // change things (especially marking unused vars). | |
| 224 const Scope* const_containing_; | |
| 225 Scope* mutable_containing_; | |
| 226 | |
| 227 const Settings* settings_; | |
| 228 | |
| 229 // Bits set for different modes. See the flag definitions in the .cc file | |
| 230 // for more. | |
| 231 unsigned mode_flags_; | |
| 232 | |
| 233 typedef base::hash_map<base::StringPiece, Record> RecordMap; | |
| 234 RecordMap values_; | |
| 235 | |
| 236 // Owning pointers. Note that this can't use string pieces since the names | |
| 237 // are constructed from Values which might be deallocated before this goes | |
| 238 // out of scope. | |
| 239 typedef base::hash_map<std::string, Scope*> NamedScopeMap; | |
| 240 NamedScopeMap target_defaults_; | |
| 241 | |
| 242 // Null indicates not set and that we should fallback to the containing | |
| 243 // scope's filter. | |
| 244 scoped_ptr<PatternList> sources_assignment_filter_; | |
| 245 | |
| 246 // Non-owning pointers, the function calls are owned by the input file which | |
| 247 // should be kept around by the input file manager. | |
| 248 typedef std::map<std::string, const FunctionCallNode*> TemplateMap; | |
| 249 TemplateMap templates_; | |
| 250 | |
| 251 typedef std::map<const void*, void*> PropertyMap; | |
| 252 PropertyMap properties_; | |
| 253 | |
| 254 typedef std::set<ProgrammaticProvider*> ProviderSet; | |
| 255 ProviderSet programmatic_providers_; | |
| 256 | |
| 257 DISALLOW_COPY_AND_ASSIGN(Scope); | |
| 258 }; | |
| 259 | |
| 260 #endif // TOOLS_GN_SCOPE_H_ | |
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Chromium Code Reviews
Issue 21084010:
Revert 214254 "Add initial prototype for the GN meta-buildsystem." (Closed)
Base URL: svn://svn.chromium.org/chrome/