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 // Sets up the root scope for a toolchain. This applies the default system 35 // flags, then any overrides stored in this object, then applies any 36 // toolchain overrides specified in the argument. 37 void SetupRootScope(Scope* dest, 38 const Scope::KeyValueMap& toolchain_overrides) const; 39 40 // Sets up the given scope with arguments passed in. 41 // 42 // If the values specified in the args are not already set, the values in 43 // the args list will be used (which are assumed to be the defaults), but 44 // they will not override the system defaults or the current overrides. 45 // 46 // All args specified in the input will be marked as "used". 47 // 48 // On failure, the err will be set and it will return false. 49 bool DeclareArgs(const Scope::KeyValueMap& args, 50 Scope* scope_to_set, 51 Err* err) const; 52 53 // Checks to see if any of the overrides ever used were never declared as 54 // arguments. If there are, this returns false and sets the error. 55 bool VerifyAllOverridesUsed(Err* err) const; 56 57 // This function is not threadsafe, it must only be used when 58 // single-threaded. It's used to implement the "args" command. 59 const Scope::KeyValueMap& declared_arguments() const { 60 return declared_arguments_; 61 } 62 63 private: 64 // Sets the default config based on the current system. 65 void SetSystemVars(Scope* scope) const; 66 67 // Sets the given vars on the given scope. 68 void ApplyOverrides(const Scope::KeyValueMap& values, Scope* scope) const; 69 70 void SaveOverrideRecord(const Scope::KeyValueMap& values) const; 71 72 // Since this is called during setup which we assume is single-threaded, 73 // this is not protected by the lock. It should be set only during init. 74 Scope::KeyValueMap overrides_; 75 76 mutable base::Lock lock_; 77 78 // Maintains a list of all overrides we've ever seen. This is the main 79 // |overrides_| as well as toolchain overrides. Tracking this allows us to 80 // check for overrides that were specified but never used. 81 mutable Scope::KeyValueMap all_overrides_; 82 83 // Tracks all variables declared in any buildfile. This is so we can see if 84 // the user set variables on the command line that are not used anywhere. 85 mutable Scope::KeyValueMap declared_arguments_; 86 87 Args& operator=(const Args& other); // Disallow assignment. 88 }; 89 90 #endif // TOOLS_GN_ARGS_H_ 91
