diff --git a/src/antlr4/SysY.g4 b/src/antlr4/SysY.g4
index 263aeef..e4e7a3c 100644
--- a/src/antlr4/SysY.g4
+++ b/src/antlr4/SysY.g4
@@ -1,98 +1,167 @@
-// SysY 子集语法：支持形如
-// int main() { int a = 1; int b = 2; return a + b; }
-// 的最小返回表达式编译。
-
-// 后续需要自行添加
-
+// SysY 扩展语法：支持变量声明、数组、控制流、函数调用及浮点数扩展
 grammar SysY;
-
 /*===-------------------------------------------===*/
 /* Lexer rules                                     */
 /*===-------------------------------------------===*/
-
+// 关键字
+CONST: 'const';
 INT: 'int';
+FLOAT: 'float';
+VOID: 'void';
+IF: 'if';
+ELSE: 'else';
+WHILE: 'while';
+BREAK: 'break';
+CONTINUE: 'continue';
 RETURN: 'return';
-
+// 运算符
 ASSIGN: '=';
 ADD: '+';
-
+SUB: '-';
+MUL: '*';
+DIV: '/';
+MOD: '%';
+EQ: '==';
+NEQ: '!=';
+LT: '<';
+GT: '>';
+LE: '<=';
+GE: '>=';
+AND: '&&';
+OR: '||';
+NOT: '!';
+// 分隔符
 LPAREN: '(';
 RPAREN: ')';
 LBRACE: '{';
 RBRACE: '}';
+LBRACK: '[';
+RBRACK: ']';
+COMMA: ',';
 SEMICOLON: ';';
-
 ID: [a-zA-Z_][a-zA-Z_0-9]*;
-ILITERAL: [0-9]+;
-
-WS: [ \t\r\n] -> skip;
+// 整型字面量
+ILITERAL
+    : [1-9][0-9]* | '0'[0-7]* | ('0x'|'0X')[0-9a-fA-F]+ 
+    ;
+// 浮点型字面量
+FLITERAL
+    : [0-9]+ '.' [0-9]* ([eE] [+-]? [0-9]+)?
+    | '.' [0-9]+ ([eE] [+-]? [0-9]+)?
+    | [0-9]+ [eE] [+-]? [0-9]+
+    | ('0x'|'0X') [0-9a-fA-F]+ '.' [0-9a-fA-F]* ([pP] [+-]? [0-9]+)?
+    | ('0x'|'0X') '.' [0-9a-fA-F]+ ([pP] [+-]? [0-9]+)?
+    | ('0x'|'0X') [0-9a-fA-F]+ [pP] [+-]? [0-9]+
+    ;
+WS: [ \t\r\n]+ -> skip;
 LINECOMMENT: '//' ~[\r\n]* -> skip;
 BLOCKCOMMENT: '/*' .*? '*/' -> skip;
-
 /*===-------------------------------------------===*/
 /* Syntax rules                                    */
 /*===-------------------------------------------===*/
-
+// 支持多个全局声明或函数定义
 compUnit
-    : funcDef EOF
+    : (decl | funcDef)+ EOF
     ;
-
 decl
-    : btype varDef SEMICOLON
+    : constDecl
+    | varDecl
+    ;
+constDecl
+    : CONST btype constDef (COMMA constDef)* SEMICOLON
     ;
-
 btype
     : INT
+    | FLOAT
+    ;
+constDef
+    : ID (LBRACK constExp RBRACK)* ASSIGN constInitVal
     ;
-
+constInitVal
+    : constExp 
+    | LBRACE (constInitVal (COMMA constInitVal)*)? RBRACE
+    ;
+varDecl
+    : btype varDef (COMMA varDef)* SEMICOLON
+    ;
+// 变量定义：支持数组维度声明
 varDef
-    : lValue (ASSIGN initValue)?
+    : ID (LBRACK constExp RBRACK)*
+    | ID (LBRACK constExp RBRACK)* ASSIGN initValue
     ;
-
+// 初始化：支持大括号数组初始化
 initValue
     : exp
+    | LBRACE (initValue (COMMA initValue)*)? RBRACE
     ;
-
+// 函数定义：增加参数列表支持
 funcDef
-    : funcType ID LPAREN RPAREN blockStmt
+    : funcType ID LPAREN (funcFParams)? RPAREN blockStmt
     ;
-
 funcType
-    : INT
+    : VOID 
+    | INT 
+    | FLOAT
+    ;
+funcFParams
+    : funcFParam (COMMA funcFParam)*
+    ;
+funcFParam
+    : btype ID (LBRACK RBRACK (LBRACK exp RBRACK)*)?
     ;
-
 blockStmt
     : LBRACE blockItem* RBRACE
     ;
-
 blockItem
     : decl
     | stmt
     ;
-
+// 语句：扩充了控制流和赋值
 stmt
-    : returnStmt
+    : lValue ASSIGN exp SEMICOLON                 # assignStmt
+    | (exp)? SEMICOLON                            # exprStmt
+    | blockStmt                                   # blockStmtNode
+    | IF LPAREN cond RPAREN stmt (ELSE stmt)?     # ifStmt
+    | WHILE LPAREN cond RPAREN stmt               # whileStmt
+    | BREAK SEMICOLON                             # breakStmt
+    | CONTINUE SEMICOLON                          # continueStmt
+    | returnStmt                                  # retStmtNode
     ;
-
 returnStmt
-    : RETURN exp SEMICOLON
+    : RETURN (exp)? SEMICOLON
     ;
-
+// 表达式：自上而下定义优先级
 exp
-    : LPAREN exp RPAREN          # parenExp
-    | var                        # varExp
-    | number                     # numberExp
-    | exp ADD exp                # additiveExp
+    : LPAREN exp RPAREN                           # parenExp
+    | lValue                                      # varExp
+    | number                                      # numberExp
+    | ID LPAREN (funcRParams)? RPAREN             # callExp
+    | unaryOp exp                                 # unaryExp
+    | exp (MUL | DIV | MOD) exp                   # mulExp
+    | exp (ADD | SUB) exp                         # additiveExp
+    | exp (LT | GT | LE | GE) exp                 # relExp
+    | exp (EQ | NEQ) exp                          # eqExp
+    | exp AND exp                                 # andExp
+    | exp OR exp                                  # orExp
+    ;
+cond
+    : exp
+    ;
+unaryOp
+    : ADD | SUB | NOT
     ;
-
-var
-    : ID
+funcRParams
+    : exp (COMMA exp)*
     ;
-
+constExp
+    : exp
+    ;
+// 左值：支持数组下标访问
 lValue
-    : ID
+    : ID (LBRACK exp RBRACK)*
     ;
-
+// 数字：合并整型与浮点型
 number
     : ILITERAL
-    ;
+    | FLITERAL
+    ;
\ No newline at end of file