From 72b3d46d08190d672a0ac5eae3a2e1e022662a6b Mon Sep 17 00:00:00 2001
From: Iru Cai <mytbk920423@gmail.com>
Date: Wed, 8 Oct 2014 22:07:00 +0800
Subject: Add check for method variables double declaration.

---
 src/minijava/symboltable/MClass.java              |  4 +---
 src/minijava/symboltable/MLocalVarType.java       | 13 ++++++++++
 src/minijava/symboltable/MMethod.java             | 18 +++++++++++++-
 src/minijava/visitor/BuildSymbolTableVisitor.java | 29 +++++++++++++++--------
 4 files changed, 50 insertions(+), 14 deletions(-)
 create mode 100644 src/minijava/symboltable/MLocalVarType.java

diff --git a/src/minijava/symboltable/MClass.java b/src/minijava/symboltable/MClass.java
index a5b90f2..4e64f54 100644
--- a/src/minijava/symboltable/MClass.java
+++ b/src/minijava/symboltable/MClass.java
@@ -5,18 +5,16 @@ package minijava.symboltable;
 
 import minijava.typecheck.PrintError;
 
-public class MClass extends MType {
+public class MClass extends MLocalVarType {
 	public MClasses all_classes; // 所有类的列表
 	public boolean isDeclared = false; // 是否已声明，用于检查符号表
 	public String extend_class_name = null; // 所继承的类
-	public MVarList vars;
 	public MMethodList methods;
 
 	public MClass(String v_name, MClasses all, int m_line, int m_column) {
 		super(m_line, m_column);
 		name = v_name;
 		all_classes = all;
-		vars = new MVarList();
 		methods = new MMethodList();
 	}
 	
diff --git a/src/minijava/symboltable/MLocalVarType.java b/src/minijava/symboltable/MLocalVarType.java
new file mode 100644
index 0000000..9824ae4
--- /dev/null
+++ b/src/minijava/symboltable/MLocalVarType.java
@@ -0,0 +1,13 @@
+/* 可定义局部变量的抽象类 */
+
+package minijava.symboltable;
+
+public abstract class MLocalVarType extends MType {
+	public MVarList vars;
+	
+	public MLocalVarType(int m_line, int m_column) {
+		super(m_line, m_column);
+		vars = new MVarList();
+	}
+	public abstract String insertVar(MVariable var);
+}
diff --git a/src/minijava/symboltable/MMethod.java b/src/minijava/symboltable/MMethod.java
index 30159cf..f4b58fa 100644
--- a/src/minijava/symboltable/MMethod.java
+++ b/src/minijava/symboltable/MMethod.java
@@ -1,11 +1,27 @@
 package minijava.symboltable;
 
-public class MMethod extends MType {
+public class MMethod extends MLocalVarType {
 	MVarList params;
 	String ret_type_name;
+	MClass method_class;
+	MVarList paramList;
 	
 	public MMethod(String m_name, int m_type, int m_column) {
 		super(m_type, m_column);
 		this.name = m_name;
+		ret_type_name = null;
+		paramList = new MVarList();
+	}
+	
+	public String insertVar(MVariable var) {
+		String var_name = var.getName();
+		if (paramList.findVar(var_name)!=-1) {
+			return "Variable \'" + var_name + "\' already in param list!";
+		}
+		if (vars.findVar(var_name)!=-1) {
+			return "Variable double declaration " + "\"" + var_name + "\"";	
+		}
+		vars.insertVar(var);
+		return null;
 	}
 }
diff --git a/src/minijava/visitor/BuildSymbolTableVisitor.java b/src/minijava/visitor/BuildSymbolTableVisitor.java
index d8d40f1..a3b6fe5 100644
--- a/src/minijava/visitor/BuildSymbolTableVisitor.java
+++ b/src/minijava/visitor/BuildSymbolTableVisitor.java
@@ -220,11 +220,11 @@ public class BuildSymbolTableVisitor extends GJDepthFirst<MType, MType> {
     */
    public MType visit(VarDeclaration n, MType argu) {
       MType _ret=null;
-      MClass m_class = (MClass)argu;
+      MLocalVarType m_class = (MLocalVarType)argu; // m_class可能是类或方法
       String var_name = n.f1.accept(this, argu).getName();
       String type_name = n.f0.accept(this, argu).getName();
       // debug
-      System.out.println("Variable: \'" + var_name + "\' from class " + m_class.getName());
+      System.out.println("Variable: \'" + var_name + "\' from class/method " + m_class.getName());
       System.out.println("It has type: " + type_name);
       
       // 建立并插入变量
@@ -256,14 +256,23 @@ public class BuildSymbolTableVisitor extends GJDepthFirst<MType, MType> {
     */
    public MType visit(MethodDeclaration n, MType argu) {
 	   MType _ret = null;
-      n.f0.accept(this, argu);
-      n.f1.accept(this, argu);
-      n.f2.accept(this, argu);
-      n.f3.accept(this, argu);
-      n.f4.accept(this, argu);
-      n.f5.accept(this, argu);
-      n.f6.accept(this, argu);
-      n.f7.accept(this, argu);
+	   MClass m_class = (MClass)argu;
+	   String ret_type = n.f1.accept(this, argu).getName();
+	   String method_name = n.f2.accept(this, argu).getName();
+	   MMethod m_method = new MMethod(method_name, n.f2.f0.beginLine, n.f2.f0.beginColumn);
+	   
+	   // 将定义的方法插入类中，如果出错则打印错误信息
+	   String _err = m_class.insertMethod(m_method);
+	   if (_err!=null) {
+		   PrintError.print(n.f2.f0.beginLine, n.f2.f0.beginColumn, _err);
+	   }
+	   
+	   // 处理参数表
+      n.f4.accept(this, m_method);
+      
+      // 函数局部变量处理      
+      n.f7.accept(this, m_method);
+      
       n.f8.accept(this, argu);
       n.f9.accept(this, argu);
       n.f10.accept(this, argu);
-- 
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