标签：clang lexer 源码 笔记 preprocesser
00082 /// \brief Context in which macro name is used.
00083 enum MacroUse {
00084 MU_Other = 0, // other than #define or #undef
00085 MU_Define = 1, // macro name specified in #define
00086 MU_Undef = 2 // macro name specified in #undef
00087 };这个枚举很简单，就是通过枚举值来确定到底使用了哪些宏。除了define和undef之外，其他的都分类到MU_Other类别下边了。00089 /// \brief Engages in a tight little dance with the lexer to efficiently
00090 /// preprocess tokens.
00091 ///
00092 /// Lexers know only about tokens within a single source file, and don‘t
00093 /// know anything about preprocessor-level issues like the \#include stack,
00094 /// token expansion, etc.
00095 class Preprocessor : public RefCountedBase<Preprocessor> {
00096 IntrusiveRefCntPtr<PreprocessorOptions> PPOpts;
00097 DiagnosticsEngine *Diags;
00098 LangOptions &LangOpts;
00099 const TargetInfo *Target;
00100 FileManager &FileMgr;
00101 SourceManager &SourceMgr;
00102 std::unique_ptr<ScratchBuffer> ScratchBuf;
00103 HeaderSearch &HeaderInfo;
00104 ModuleLoader &TheModuleLoader;
这里可以看到Preprocessor的类的定义，而它是模板类RefCountedBase<Preprocessor>的子类。同时可以看看这几个类的几个成员变量，DiagnosticsEngine-诊断引擎，LangOptions-接收的编译选项，TargetInfo-存储目标信息，FileManager-文件管理器，SourceManager-源码管理器，ModuleLoader-module加载器。00118 /// Identifiers for builtin macros and other builtins. 00119 IdentifierInfo *Ident__LINE__, *Ident__FILE__; // __LINE__, __FILE__ 00120 IdentifierInfo *Ident__DATE__, *Ident__TIME__; // __DATE__, __TIME__ 00121 IdentifierInfo *Ident__INCLUDE_LEVEL__; // __INCLUDE_LEVEL__ 00122 IdentifierInfo *Ident__BASE_FILE__; // __BASE_FILE__ 00123 IdentifierInfo *Ident__TIMESTAMP__; // __TIMESTAMP__ 00124 IdentifierInfo *Ident__COUNTER__; // __COUNTER__ 00125 IdentifierInfo *Ident_Pragma, *Ident__pragma; // _Pragma, __pragma 00126 IdentifierInfo *Ident__identifier; // __identifier 00127 IdentifierInfo *Ident__VA_ARGS__; // __VA_ARGS__ 00128 IdentifierInfo *Ident__has_feature; // __has_feature 00129 IdentifierInfo *Ident__has_extension; // __has_extension 00130 IdentifierInfo *Ident__has_builtin; // __has_builtin 00131 IdentifierInfo *Ident__has_attribute; // __has_attribute 00132 IdentifierInfo *Ident__has_include; // __has_include 00133 IdentifierInfo *Ident__has_include_next; // __has_include_next 00134 IdentifierInfo *Ident__has_warning; // __has_warning 00135 IdentifierInfo *Ident__is_identifier; // __is_identifier 00136 IdentifierInfo *Ident__building_module; // __building_module 00137 IdentifierInfo *Ident__MODULE__; // __MODULE__ 00138 IdentifierInfo *Ident__has_cpp_attribute; // __has_cpp_attribute另外Preprocesser类中包含了使用IdentifierInfo指针所保存的内建宏以及其他的内建的标示符。
深入研究Clang（六） Clang Lexer代码阅读笔记之Preprocesser
标签：clang lexer 源码 笔记 preprocesser
原文地址：http://blog.csdn.net/snsn1984/article/details/41645487
