MiniC 编译器

这是我们在 doraHack 上用 C++ 编写的一个 miniC 编译器。

标记（Token）

• keywords = if|else|while|for|switch|case|deafult|break|return|void|int|char|scan|print
• letter = a | ... | z | A | ... | Z
• digit = 0 | ... | 9
• space = '\t',' ','\n'
• NUM = digit+
• ID = letter(letter|digit)*
• STRING = "最多 1024 个字符. " 可以被 \ 转义."
• CHAR = '任何字符'
• PLUS = +
• MINUS = -
• DIV = /
• MULT = *
• MOD = %
• PLUS2 = ++
• MINUS2 = --
• ASSIGN = =
• EQUAL = ==
• GREATER = >
• GREATEREQUAL = >=
• LESS = <
• LESSEQUAL = <=
• NOTEQUAL = !=
• LBRAC = {
• RBRAC = }
• LPAREN = (
• RPAREN = )
• LBRACE = [
• RBRACE = ]
• COLON = :
• COMMA = ,
• SEMICOLON = ;
• END_OF_FILE = EOF

文法（Grammar）

Program → FunClosure

FunClosure → Function FunClosure | ε

Function → Type Variable(ParameterDecl){FunBody}

Function → void Variable(ParameterDecl){FunBody}

Type → int | char

Variable → ID

Factor → (Expression)

Factor → VarOrFunCall

Factor → NUM | CHAR

VarOrFunCall → Variable FunSuffix

FunSuffix → (VariableList) | ε

Expression → FactorCombine Term

FactorCombine → Factor FactorRecur

FactorRecur → * Factor FactorRecur

FactorRecur → / Factor FactorRecur

FactorRecur → % Factor FactorRecur

FactorRecur → ε

Term → + FactorCombine Term

Term → - FactorCombine Term

Term → ε

ParameterDecl → Decl DeclClosure | void | ε

Decl → Type Variable Assign

Assign → RightVal | ε

RightVal → Expression

DeclClosure → , Decl DeclClosure | ε

FunBody → DeclStmtClosure FunClosure

DeclStmtClosure → DeclStmt DeclStmtClosure | ε

DeclStmt → Decl ;

FunClosure → AssignStmt FunClosure

FunClosure → ForStmt FunClosure

FunClosure → Condition FunClosure

FunClosure → ReturnStmt FunClosure

FunClosure → ScanStmt FunClosure

FunClosure → PrintStmt FunClosure

FunClosure → ε

AssignStmt → Variable AssignOrFunCall

AssignOrFunCall → RightVal ;

AssignOrFunCall → (ParameterList) ;

ParameterList → Parameter ParameterClosure

ParameterClosure → , Parameter ParameterClosure

ParameterClosure → ε

Parameter → ID | NUM | CHAR

ForStmt → for (AssignStmt LogicStmt; SuffixStmt){FunctionBody}

MultLogicExpr → LogiExpr MultLogiExprRecur

MultLogiExprRecur → AdvanLogiOp MultLogicExpr | ε

AdvanLogiOp → AND | OR

LogiExpr → Expr LogiExprRecur

LogiExprRecur → LogicOp LogiExpr | ε

LogicOp → LESS | LESSEQUAL | NOTEQUAL | EQUAL | GREATER | GREATEREQUAL

SuffixStmt → Variable SuffixOp

SuffixOp → PLUS2 | MINUS2

IfStmt → IF ( MultLogicExpr ) { FunctionBody } ElseStmt

ElseStmt → ELSE { FunctionBody } | ε

ReturnStmt → RETURN Factor ;

ScanStmt → SCAN ( Variable ) ;

PrintStmt → PRINT ( Variable ) ; | PRINT ( STRING ) ;

模块（Modules）

词法分析器 Lexer

Lexer 读取字符，并组成符合要求的标记（Token）。

语法分析器 Paser

Paser 从 Lexer 中读取 Token ，并转换为中间表达式。