From 92e66882890693adee8d72b66c5ffefdf7afb8bd Mon Sep 17 00:00:00 2001
From: Apoorva Ranade <apoorvaranade02@gmail.com>
Date: Sun, 7 Mar 2021 15:35:34 +0530
Subject: [PATCH] Added semantic check for duplicate local variable declaration

---
 .../common/analysis/types/FuncType.java       |  6 +-
 .../java/chocopy/pa2/DeclarationAnalyzer.java | 67 +++++++++++++++++--
 2 files changed, 67 insertions(+), 6 deletions(-)

diff --git a/src/main/java/chocopy/common/analysis/types/FuncType.java b/src/main/java/chocopy/common/analysis/types/FuncType.java
index 69fdefc..f729958 100644
--- a/src/main/java/chocopy/common/analysis/types/FuncType.java
+++ b/src/main/java/chocopy/common/analysis/types/FuncType.java
@@ -8,11 +8,15 @@ import java.util.List;
 /** Semantic information for a function or method. */
 public class FuncType extends Type {
 
+    /** Function's name. */
+    //public final String name;
+    
     /** Types of parameters. */
-    public final List<ValueType> parameters;
+    public List<ValueType> parameters;
     /** Function's return type. */
     public final ValueType returnType;
 
+
     /** Create a FuncType returning RETURNTYPE0, initially parameterless. */
     public FuncType(ValueType returnType0) {
         this(new ArrayList<>(), returnType0);
diff --git a/src/main/java/chocopy/pa2/DeclarationAnalyzer.java b/src/main/java/chocopy/pa2/DeclarationAnalyzer.java
index 29aaf5a..9f9673f 100644
--- a/src/main/java/chocopy/pa2/DeclarationAnalyzer.java
+++ b/src/main/java/chocopy/pa2/DeclarationAnalyzer.java
@@ -2,15 +2,14 @@ package chocopy.pa2;
 
 import chocopy.common.analysis.AbstractNodeAnalyzer;
 import chocopy.common.analysis.SymbolTable;
-import chocopy.common.analysis.types.Type;
-import chocopy.common.analysis.types.ValueType;
+import chocopy.common.analysis.types.*;
 import chocopy.common.astnodes.*;
 
 /** Analyzes declarations to create a top-level symbol table. */
 public class DeclarationAnalyzer extends AbstractNodeAnalyzer<Type> {
 
     /** Current symbol table. Changes with new declarative region. */
-    private final SymbolTable<Type> sym = new SymbolTable<>();
+    private SymbolTable<Type> sym = new SymbolTable<>();
     /** Global symbol table. */
     private final SymbolTable<Type> globals = sym;
     /** Receiver for semantic error messages. */
@@ -30,9 +29,8 @@ public class DeclarationAnalyzer extends AbstractNodeAnalyzer<Type> {
         for (Declaration decl : program.declarations) {
             Identifier id = decl.getIdentifier();
             String name = id.name;
-
             Type type = decl.dispatch(this);
-
+            
             if (type == null) {
                 continue;
             }
@@ -52,4 +50,63 @@ public class DeclarationAnalyzer extends AbstractNodeAnalyzer<Type> {
     public Type analyze(VarDef varDef) {
         return ValueType.annotationToValueType(varDef.var.type);
     }
+    @Override
+    public Type analyze(FuncDef node) {
+        FuncType current_func=new FuncType((ValueType) node.returnType.dispatch(this));
+        SymbolTable current_scope=new SymbolTable<>(sym);
+        sym=current_scope;
+        for (TypedVar param : node.params) 
+        {
+            
+            if (sym.declares(param.identifier.name)) 
+            {
+                errors.semError(
+                        node.name, "Duplicate declaration of identifier in same " + "scope: %s", param.identifier.name);
+                continue;
+            }
+            /*
+            else if (sym.get(param.identifier.name)!= null) 
+            {
+                System.out.println("Error:"+sym.get(param.identifier.name));
+                errors.semError(
+                        node.name, "Parameter shadows class name: %s", param.identifier.name);
+                continue;
+            }*/
+
+            Type p = param.dispatch(this);
+            current_func.parameters.add((ValueType)p);
+            sym.put(param.identifier.name, p);
+        }
+
+        for (Declaration decl : node.declarations) {
+            Identifier id = decl.getIdentifier();
+            String name = id.name;
+            Type type = decl.dispatch(this);
+            
+            
+            if (type == null) {
+                continue;
+            }
+
+            if (sym.declares(name)) {
+                errors.semError(
+                        id, "Duplicate declaration of identifier in same " + "scope: %s", name);
+            } else {
+                sym.put(name, type);
+            }
+        }
+        sym = sym.getParent();
+        return current_func;
+    }
+    @Override
+    public Type analyze(GlobalDecl node) 
+    {
+        if (globals.declares(node.variable.name)==false) 
+        {
+            errors.semError(
+                node.variable, "Not a global variable: %s", node.variable.name);
+            return null;
+        }
+        return globals.get(node.variable.name);
+    }
 }