From 60710cc10b1be037d3246083c104997d34f75b6a Mon Sep 17 00:00:00 2001
From: Iru Cai <mytbk920423@gmail.com>
Date: Sat, 25 Oct 2014 16:54:18 +0800
Subject: Add  functions for getting binding

---
 src/minijava/symboltable/MClass.java  | 78 +++++++++++++++++++++++++++++++++++
 src/minijava/symboltable/MMethod.java | 46 ++++++++++++++++++++-
 2 files changed, 123 insertions(+), 1 deletion(-)

diff --git a/src/minijava/symboltable/MClass.java b/src/minijava/symboltable/MClass.java
index 10354a8..ec57c19 100644
--- a/src/minijava/symboltable/MClass.java
+++ b/src/minijava/symboltable/MClass.java
@@ -3,6 +3,8 @@
  */
 package minijava.symboltable;
 
+import minijava.minijava2piglet.PigletBinding;
+import minijava.minijava2piglet.PigletTemp;
 import minijava.typecheck.PrintError;
 
 public class MClass extends MLocalVarType {
@@ -42,6 +44,82 @@ public class MClass extends MLocalVarType {
 		return null;
 	}
 	
+	public MMethod findMethodByName(String m) {
+		int idx = methods.findMethod(m);
+		if (idx==-1) {
+			return null;
+		} else {
+			return methods.methods.elementAt(idx);
+		}
+	}
+	
+	public PigletBinding getVarBinding(String v_name) {
+		int prev_vars = 0;
+		for (MClass c=extend_class; c!=null; c=c.extend_class) {
+			prev_vars += c.vars.size();
+		}
+		int idx = vars.findVar(v_name);
+		if (idx!=-1) {
+			String tmp = PigletTemp.newTmp();
+			PigletBinding ret = new PigletBinding(null, null);
+			ret.read = "\nBEGIN\nHLOAD " + tmp + " TEMP 0 " + (prev_vars+idx+1)*4
+					+ "\nRETURN " + tmp + "\nEND";
+			ret.write = "TEMP 0 " + (prev_vars+idx+1)*4;
+			return ret;
+		}
+		// no such variable, find the parentclss
+		if (extend_class!=null) {
+			return extend_class.getVarBinding(v_name);
+		} else {
+			return null;
+		}
+	}
+	
+	public int getMethodBinding(String m_name) {
+		int prev_funcs = 0;
+		for (MClass c=extend_class; c!=null; c=c.extend_class) {
+			prev_funcs += c.methods.size();
+		}
+		int idx = methods.findMethod(m_name);
+		if (idx!=-1) {
+			return (prev_funcs+idx)*4;
+		} else {
+			// no such function, find the parentclass
+			if (extend_class!=null) {
+				return extend_class.getMethodBinding(m_name);
+			} else {
+				return -1;
+			}
+		}
+	}
+	
+	public String newString() {
+		int nMethods = 0, nVars = 0;
+		String result = "";
+		String t_methods = PigletTemp.newTmp();
+		String t_vars = PigletTemp.newTmp();
+		
+		for (MClass c=this; c!=null; c=c.extend_class) {
+			nMethods += c.methods.size();
+			nVars += c.vars.size();
+		}
+		result += "\nBEGIN\nMOVE " + t_methods + " HALLOCATE " + nMethods*4
+				+ "\nMOVE " + t_vars + " HALLOCATE " + (nVars+1)*4 + "\n";
+		// store all methods
+		for (MClass c=this; c!=null; c=c.extend_class) {
+			for (int i=c.methods.size()-1; i>=0; i--) {
+				--nMethods;
+				result += "HSTORE " + t_methods + " " + nMethods*4 + " "
+						+ c.getName() + "_" 
+						+ c.methods.methods.elementAt(i).getName()
+						+ "\n";
+			}
+		}
+		result += "HSTORE " + t_vars + " 0 " + t_methods + "\n";
+		result += "RETURN " + t_vars + "\nEND";
+		return result;
+	}
+	
 	// 检测类型名是否有效
 	public boolean validType(String s_type) {
 		if (s_type==MIdentifier.intType
diff --git a/src/minijava/symboltable/MMethod.java b/src/minijava/symboltable/MMethod.java
index 9e770a3..fc70bdb 100644
--- a/src/minijava/symboltable/MMethod.java
+++ b/src/minijava/symboltable/MMethod.java
@@ -1,14 +1,20 @@
 package minijava.symboltable;
 
+import java.util.HashMap;
+import java.util.Map;
+
+import minijava.minijava2piglet.PigletBinding;
+import minijava.minijava2piglet.PigletTemp;
 import minijava.typecheck.PrintError;
 
 public class MMethod extends MLocalVarType {
 	MVarList params;
 	public String ret_type_name;
 	public MClass method_class;
-	MVarList paramList;
+	public MVarList paramList;
 	public MStatementList statements;
 	public MExpression ret_expr;
+	public HashMap<String, String> varBinding;
 	
 	public MMethod(String m_name, String ret_type, int m_line, int m_column) {
 		super(m_line, m_column);
@@ -109,6 +115,44 @@ public class MMethod extends MLocalVarType {
 		return null;
 	}
 	
+	// generate local variable bindings, call it when visitor visits the method
+	public void genLocalVarBindings() {
+		varBinding = new HashMap<String, String>();
+		for (int i=0; i<vars.size(); i++) {
+			varBinding.put(vars.varlist.elementAt(i).getName(), PigletTemp.newTmp());
+		}
+	}
+	
+	// get a binding, call it when visitor visits a statement
+	public PigletBinding getBinding(String id) {
+		String result;
+		result = varBinding.get(id);
+		if (result!=null) {
+			return new PigletBinding(result, null);
+		}
+		// not in local variables, then find paramlist
+		for (int i=0; i<paramList.size(); i++) {
+			if (paramList.varlist.elementAt(i).name.equals(id)) {
+				if (i<18 || paramList.size()<20) {
+					result = "TEMP "+(i+1);
+					return new PigletBinding(result, null);
+				} else {
+					// >=20 parameters, the last parameter should be a pointer to 
+					// the rest parameters
+					int restidx = i-18;
+					String tmp = PigletTemp.newTmp();
+					PigletBinding ret = new PigletBinding(null, null);
+					ret.read = "BEGIN\nHLOAD " + tmp + 
+							" TEMP 19 " + restidx + "RETURN " + tmp + "\nEND";
+					ret.write = "TEMP 19 " + restidx;
+					return ret;
+				}
+			}
+		}
+		// not in paramList either, check for the class
+		return method_class.getVarBinding(id);
+	}
+	
 	public void checkStatements() {
 		statements.checkStatements(this);
 		// 检查返回类型是否和返回值匹配
-- 
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