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_ARGS_H_ 6 #define TOOLS_GN_ARGS_H_ 7 8 #include "base/basictypes.h" 9 #include "base/containers/hash_tables.h" 10 #include "base/synchronization/lock.h" 11 #include "tools/gn/err.h" 12 #include "tools/gn/scope.h" 13 14 extern const char kBuildArgs_Help[]; 15 16 // Manages build arguments. It stores the global arguments specified on the 17 // command line, and sets up the root scope with the proper values. 18 // 19 // This class tracks accesses so we can report errors about unused variables. 20 // The use case is if the user specifies an override on the command line, but 21 // no buildfile actually uses that variable. We want to be able to report that 22 // the argument was unused. 23 class Args { 24 public: 25 Args(); 26 Args(const Args& other); 27 ~Args(); 28 29 // Specifies overrides of the build arguments. These are normally specified 30 // on the command line. 31 void AddArgOverride(const char* name, const Value& value); 32 void AddArgOverrides(const Scope::KeyValueMap& overrides); 33 34 // Returns the value corresponding to the given argument name, or NULL if no 35 // argument is set. 36 const Value* GetArgOverride(const char* name) const; 37 38 // Gets all overrides set on the build. 39 Scope::KeyValueMap GetAllOverrides() const; 40 41 // Sets up the root scope for a toolchain. This applies the default system 42 // flags, then any overrides stored in this object, then applies any 43 // toolchain overrides specified in the argument. 44 void SetupRootScope(Scope* dest, 45 const Scope::KeyValueMap& toolchain_overrides) const; 46 47 // Sets up the given scope with arguments passed in. 48 // 49 // If the values specified in the args are not already set, the values in 50 // the args list will be used (which are assumed to be the defaults), but 51 // they will not override the system defaults or the current overrides. 52 // 53 // All args specified in the input will be marked as "used". 54 // 55 // On failure, the err will be set and it will return false. 56 bool DeclareArgs(const Scope::KeyValueMap& args, 57 Scope* scope_to_set, 58 Err* err) const; 59 60 // Checks to see if any of the overrides ever used were never declared as 61 // arguments. If there are, this returns false and sets the error. 62 bool VerifyAllOverridesUsed(Err* err) const; 63 64 // Like VerifyAllOverridesUsed but takes the lists of overrides specified and 65 // parameters declared. 66 static bool VerifyAllOverridesUsed( 67 const Scope::KeyValueMap& overrides, 68 const Scope::KeyValueMap& declared_arguments, 69 Err* err); 70 71 // Adds all declared arguments to the given output list. If the values exist 72 // in the list already, their values will be overwriten, but other values 73 // already in the list will remain. 74 void MergeDeclaredArguments(Scope::KeyValueMap* dest) const; 75 76 private: 77 // Sets the default config based on the current system. 78 void SetSystemVarsLocked(Scope* scope) const; 79 80 // Sets the given vars on the given scope. 81 void ApplyOverridesLocked(const Scope::KeyValueMap& values, 82 Scope* scope) const; 83 84 void SaveOverrideRecordLocked(const Scope::KeyValueMap& values) const; 85 86 // Since this is called during setup which we assume is single-threaded, 87 // this is not protected by the lock. It should be set only during init. 88 Scope::KeyValueMap overrides_; 89 90 mutable base::Lock lock_; 91 92 // Maintains a list of all overrides we've ever seen. This is the main 93 // |overrides_| as well as toolchain overrides. Tracking this allows us to 94 // check for overrides that were specified but never used. 95 mutable Scope::KeyValueMap all_overrides_; 96 97 // Tracks all variables declared in any buildfile. This is so we can see if 98 // the user set variables on the command line that are not used anywhere. 99 mutable Scope::KeyValueMap declared_arguments_; 100 101 Args& operator=(const Args& other); // Disallow assignment. 102 }; 103 104 #endif // TOOLS_GN_ARGS_H_ 105
