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C_Minus Compiler Project

C_Minus Compiler Project. What do we support?. 数据类型： Integer, char, float,void 数据类型：数组，函数 算术运算符：+、-、*、/； 关系运算符：>、<、>=、<=、==、!=; 逻辑运算符：与、或、非； 语句结构：条件句、循环语句、说明语句、赋值语句、 转移语句等。. What do we generate?. P-Code 数学运算 : adi, adf, subi, subf, multi, multf, divi, divf

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C_Minus Compiler Project

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  1. C_Minus Compiler Project

  2. What do we support? 数据类型： Integer, char, float,void 数据类型：数组，函数 算术运算符：+、-、*、/； 关系运算符：>、<、>=、<=、==、!=; 逻辑运算符：与、或、非； 语句结构：条件句、循环语句、说明语句、赋值语句、 转移语句等。

  3. What do we generate? P-Code 数学运算 :adi, adf, subi, subf, multi, multf, divi, divf 关系运算 :grt, les, leq, geq, equ, neq 流程控制 :fjp, ujp, lab 函数 :mst, cup, ret, ent load & store :lodi, lodf, lodc, lodci, lodcf, lodcc, lda, sto, stn

  4. 开始 词法分析 语法分析 语法树 代码生成 类型检查 建立符号表 符号表 结束 How do we do it?

  5. C_Minus的语法树(数据结构1) enum NodeKind {StmtK,ExpK,DeclK}; enum StmtKind {IfK,WhileK,ForK,ReturnK,CompoundK}; enum ExpKind {TypeK,OpK,NotK,ArrayK,ConstK,IdK,CallK}; enum DeclKind {VarDeclK,FuncDeclK,FuncDefK,ParamK};

  6. C_Minus的语法树(数据结构2) struct TreeNode{ struct TreeNode * child[MAXCHILDREN]; struct TreeNode * sibling; int lineno; NodeKind nodekind; union {StmtKind stmt; ExpKind exp; DeclKind decl; } kind; union { TokenType op; int vali; float valf; char valch; char *name; ExpType vartype; } attr; ExpType type; /* for type checking of exps */ VarKind varK; };

  7. While: StmtK Test: ExpK Body: StmtK If: StmtK Test: ExpK Body: stmtK Else: stmtK C_Minus 的语法树(语句1) If statement While statement

  8. For: stmtK Initial: ExpK Test:ExpK Operation:ExpK Body:StmtK Return:StmtK Body : StmtK C_Minus 的语法树(语句2) For statement Return statement

  9. Compound:StmtK StmtK/DeclK StmtK/DeclK C_Minus 的语法树(语句3) Compound statement

  10. ArrayK ExpK CallK Name:IdK Arg:ExpK Arg:ExpK C_Minus 的语法树(表达式1) 数组 函数

  11. FuncDeclK Return Type: TypeK Name:IdK Param_list VarDeclK TypeK Var-list C_Minus 的语法树(声明1) 变量声明 函数声明

  12. FuncDeclK Return Type: TypeK Name:IdK Param_list CompoundK C_Minus 的语法树(声明2) 函数定义

  13. Symbol Table 示例程序： fn( ){ int m; if ( ){int n; …} else {int I; …} } int u; main( ){ char c; … }

  14. Fn , u m c n i Symbol Table 第一层:函数和全局变量 第2,3,4…层:局部变量

  15. Symbol Table的数据结构 struct SymTab{ BucketList * hashTable[SIZE]; SymTab * child; //指向下一层的符号表 SymTab * parent; //指向上层的符号表 SymTab * sibling; //指向同层的符号表 };

  16. Bucklist 的数据结构 struct BucketList{ char * name; char * fname; LineList * lines; entryType entrytype; int memloc; int size; paramType * param; struct BucketList * next; };

  17. Symbol Table的接口函数（1） int st_insert( char * name, int lineno, ExpType type, ExpKind kind, int size = -1); int st_insert( char * name, int lineno, ExpType type, TreeNode * params); int st_lookup ( char * , Result &); int st_funclookup(char *, ExpType, TreeNode * params); int st_funclookup(char *, Result &);

  18. Symbol Table的接口函数（2） int st_setLoc(char * name ,int memloc ); void st_newBuck(); void st_delBuck(); void st_reset(); void st_inFunc(char * name); void st_outFunc(); void printSymTab(FILE * listing);

  19. Type Checking的实现 struct TreeNode{ ………………. ………………. ExpType type; /* for type checking of exps */ VarKind varK; /* Array/Func/Norm */ }; 通过对树的后序遍历实现。首先计算一个结点的儿子的类型，存放在结点的type成员变量中，然后根据结点类型进行类型检查。

  20. 示例 • (1) int x[10]; • Fn(x); x.varK = Array x.type = Integer • X[1] = 9; x.varK = Norm x.type = Integer • int Fn( ); • x = Fn( ); Fn.varK = Func Fn.type = Integer

  21. 运算规则 类型计算的规则有以下几条： IdK，ArrayK，ConstK的type由建立符号表的过程中赋值 算术运算符的type等于两端的类型(允许int到float型的转换)； 逻辑运算符的type为Boolean； 类型不匹配的情况有以下几种： 操作符的两端类型不一致(int和float可以转换除外)； if，for，while语句的条件不是Boolean类型； Return type和函数定义不一致；

  22. Control Macros • /* set NO_PARSE to TRUE to get a scanner-only compiler */ • #define NO_PARSE FALSE • /* set NO_ANALYZE to TRUE to get a parser-only compiler */ • #define NO_ANALYZE FALSE • /* set NO_CODE to TRUE to get a compiler that does not • * generate code • */ • #define NO_CODE FALSE

  23. Some Global Variables? • int TraceScan; • int TraceParse; • int TraceAnalyze; • int TraceCode;

  24. Important Functions int getToken(); /*取得一个Token*/ void yyerror(const char * message); /*打印错误信息*/ void emitComment(char *c); /*在P-Code中打印注释*/ void emitCode(char *s); /*输出一条P-Code*/ void codeGen(TreeNode * syntaxTree, char * codefile); /*代码生成部分 的接口*/

  25. Code Generate • 执行代码生成任务的函数是： static void cGen( TreeNode * tree) • 它由根结点遍历语法树每个节点，并对每个结点递归地生成P-code。 • 先对语法树的结点分成三大类：语句结点（StmtK），表达式结点（ExpK），声明结点（DeclK），然后逐个用对应函数进行处理。三个函数分别是： genStmt(tree); genExp(tree, TRUE); genDecl(tree);

  26. Code Generate switch (tree->nodekind) { case StmtK: genStmt(tree); break; case ExpK: genExp(tree, TRUE); //set to TRUE for destructive store break; case DeclK: genDecl(tree); break; } cGen(tree->sibling);

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