Merge pull request #1 from nyu-compiler-construction/apoorva/semantic

Added semantic check for duplicate local variable declaration

WORKLOG.md

@@ -0,0 +1,15 @@
+# Compiler Construction PA2 Worklog
+
+## Team:
+**Apoorva Ranade**(ar6496)   **Sanjar Ahmadov**(sa5640)   **Yinqi Sun**(ys3540)
+<br>
+
+## Passes:
+   - 
+## Recovery:
+ -  
+
+## Challenges:
+ -  
+## Improvements: 
+ - Added more tests to rigorously check program flow and indentation.

src/main/java/chocopy/common/analysis/types/ClassVType.java

@@ -0,0 +1,56 @@
+package chocopy.common.analysis.types;
+
+import chocopy.common.astnodes.ClassType;
+import chocopy.common.astnodes.Identifier;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import chocopy.common.analysis.SymbolTable;
+import java.util.Objects;
+
+/** Represents the semantic value of a simple class reference. */
+public class ClassVType extends ValueType {
+
+    /** The name of the class. */
+    public final String className;
+    public SymbolTable<Type> scope;
+    public ClassVType super_class;
+    /** A class type for the class named CLASSNAME. */
+    @JsonCreator
+    public ClassVType(@JsonProperty String className) {
+        this.className = className;
+    }
+
+    /** A class type for the class referenced by CLASSTYPEANNOTATION. */
+    public ClassVType(ClassType classTypeAnnotation) {
+        this.className = classTypeAnnotation.className;
+    }
+
+    @Override
+    @JsonProperty
+    public String className() {
+        return className;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        ClassVType classType = (ClassVType) o;
+        return Objects.equals(className, classType.className);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(className);
+    }
+
+    @Override
+    public String toString() {
+        return className;
+    }
+}

src/main/java/chocopy/common/analysis/types/FuncType.java

@@ -8,11 +8,13 @@ import java.util.List;
 /** Semantic information for a function or method. */
 public class FuncType extends Type {
 
+    
     /** Types of parameters. */
     public final 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);

src/main/java/chocopy/common/analysis/types/FuncValueType.java

@@ -0,0 +1,49 @@
+package chocopy.common.analysis.types;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/** Semantic information for a function or method. */
+public class FuncValueType extends Type {
+
+    /** Function's name. */
+    //public final String name;
+    
+    /** Types of parameters. */
+    public List<ValueType> parameters;
+    /** Function's return type. */
+    public final ValueType returnType;
+
+
+    /** Create a FuncType returning RETURNTYPE0, initially parameterless. */
+    public FuncValueType(ValueType returnType0) {
+        this(new ArrayList<>(), returnType0);
+    }
+
+    /**
+     * Create a FuncType for NAME0 with formal parameter types PARAMETERS0, returning type
+     * RETURNTYPE0.
+     */
+    @JsonCreator
+    public FuncValueType(List<ValueType> parameters0, ValueType returnType0) {
+        this.parameters = parameters0;
+        this.returnType = returnType0;
+    }
+
+    @Override
+    public boolean isFuncType() {
+        return true;
+    }
+
+    /** Return the type of the K-th parameter. */
+    public ValueType getParamType(int k) {
+        return parameters.get(k);
+    }
+
+    @Override
+    public String toString() {
+        return "<function>";
+    }
+}

src/main/java/chocopy/pa2/DeclarationAnalyzer.java

@@ -2,54 +2,278 @@ 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.*;
-
+import java.util.*;
 /** Analyzes declarations to create a top-level symbol table. */
-public class DeclarationAnalyzer extends AbstractNodeAnalyzer<Type> {
+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. */
     private final Errors errors;
-
+    private ClassVType current_class=null;
     /** A new declaration analyzer sending errors to ERRORS0. */
-    public DeclarationAnalyzer(Errors errors0) {
+    public DeclarationAnalyzer(Errors errors0) 
+    {
         errors = errors0;
+        ClassVType cvt = new ClassVType("object");
+        FuncValueType init = new FuncValueType(Type.OBJECT_TYPE);
+        init.parameters.add(Type.OBJECT_TYPE);
+        SymbolTable<Type> cvt_scope=new SymbolTable<>(sym);
+        cvt_scope.put("init",init);
+        cvt.scope=cvt_scope;
+        sym.put("object", cvt);
+        cvt = new ClassVType("int");
+        init = new FuncValueType(Type.INT_TYPE);
+        init.parameters.add(Type.INT_TYPE);
+        cvt_scope=new SymbolTable<>(sym);
+        cvt_scope.put("init",init);
+        cvt.scope=cvt_scope;
+        sym.put("int", cvt);
+        cvt = new ClassVType("str");
+        init = new FuncValueType(Type.STR_TYPE);
+        init.parameters.add(Type.STR_TYPE);
+        cvt_scope=new SymbolTable<>(sym);
+        cvt_scope.put("init",init);
+        cvt.scope=cvt_scope;
+        sym.put("str", cvt);
+        cvt = new ClassVType("bool");
+        init = new FuncValueType(Type.BOOL_TYPE);
+        init.parameters.add(Type.BOOL_TYPE);
+        cvt_scope=new SymbolTable<>(sym);
+        cvt_scope.put("init",init);
+        cvt.scope=cvt_scope;
+        sym.put("bool", cvt);
     }
 
-    public SymbolTable<Type> getGlobals() {
+    public SymbolTable<Type> getGlobals() 
+    {
         return globals;
     }
 
     @Override
-    public Type analyze(Program program) {
-        for (Declaration decl : program.declarations) {
+    public Type analyze(Program program) 
+    {
+        for (Declaration decl : program.declarations) 
+        {
             Identifier id = decl.getIdentifier();
             String name = id.name;
-
             Type type = decl.dispatch(this);
             
-            if (type == null) {
+            if (type == null) 
+            {
                 continue;
             }
 
-            if (sym.declares(name)) {
+            if (sym.declares(name)) 
+            {
                 errors.semError(
                         id, "Duplicate declaration of identifier in same " + "scope: %s", name);
-            } else {
+            }
+            else if (sym.get(name)!= null && sym.get(name) instanceof ClassVType)
+            {
+                errors.semError(
+                    id, "Cannot shadow class name: %s", name);
+                continue;
+            }
+            else 
+            {
                 sym.put(name, type);
             }
         }
-
+        // Check for return statements at top
+        for (Stmt stmt : program.statements) 
+        {
+            if (stmt instanceof ReturnStmt)
+            errors.semError(
+                stmt, "Return statement cannot appear at the top level");
+        }
         return null;
     }
+    @Override
+    public Type analyze(FuncDef node) {
+        FuncValueType current_func=new FuncValueType((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 && sym.get(param.identifier.name) instanceof ClassVType)
+            {
+                errors.semError(
+                    param.identifier, "Cannot shadow 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);
+                continue;
+            } 
+            else if (sym.get(name)!= null && sym.get(name) instanceof ClassVType)
+            {
+                errors.semError(id, "Cannot shadow class name: %s", name);
+                continue;
+            }
+            else 
+            {
+                sym.put(name, type);
+            }
+        }
+        /*for(String s:sym.getDeclaredSymbols())
+            System.out.println(" "+s);*/
+        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);
+    }
+    public boolean compare_functions(FuncValueType fun1, FuncValueType fun2) {
+        if (fun1.returnType.equals(fun2.returnType)==false)
+            return false;
+        if (fun1.parameters.size() != fun2.parameters.size())
+            return false;
+        for (int i=1; i<fun1.parameters.size(); i++)
+            if (fun1.parameters.get(i).equals(fun2.parameters.get(i))==false)
+                return false;
+        return true;
+    }
+    @Override
+    public Type analyze(ClassDef node) 
+    {
+        ClassVType cvt=new ClassVType(node.name.name);
+        SymbolTable<Type> current_scope=new SymbolTable<>(sym);
+        sym=current_scope;
+        current_class=cvt;
+        Type super_class = sym.get(node.superClass.name);
+        cvt.super_class = (ClassVType)super_class;
+        SymbolTable<Type> super_scope=null;
+        Set<String> super_syms=null;
+        if (super_class == null) 
+        {
+            errors.semError(
+                        node.name, "Super-class not defined: %s", node.superClass.name);
+        }
+        else if ((super_class instanceof ClassVType)==false) 
+        {
+            errors.semError(
+                        node.name, "Super-class must be a class: %s", node.superClass.name);
+        }
+        else if (node.superClass.name.equals("int") || node.superClass.name.equals("bool") || node.superClass.name.equals("str")) 
+        {
+            errors.semError(
+                        node.name, "Cannot extend special class: %s", node.superClass.name);
+        }
+        else
+        {
+            super_scope = cvt.super_class.scope;
+            super_syms = super_scope.getDeclaredSymbols();
+            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);
+                }
+                if (type instanceof ClassVType || type instanceof ListValueType) 
+                {//Check for attribute type
+                    if (super_syms.contains(name)) 
+                    {//Check for redefined superclass attribute
+                        errors.semError(
+                            id, "Cannot re-define attribute: %s", name);
+                    } 
+                    else
+                        sym.put(name, type);
+                }
+                else if(type instanceof FuncValueType)
+                {//For function declarations
+                    List<ValueType> params = ((FuncValueType)type).parameters;
+                    if(params.size() < 1 || (params.get(0) instanceof ClassVType==false) || ((ClassVType)params.get(0)).className.equals(current_class.className)==false)
+                        errors.semError(
+                            id, "First parameter of method must be of same class: %s", name);    
+                    if (super_syms.contains(name)) 
+                    {
+                        if ((super_scope.get(id.name) instanceof FuncValueType)==false) 
+                            errors.semError(id, "Cannot re-define attribute: %s" + name);
+                        else 
+                        {
+                            FuncValueType super_func = (FuncValueType) super_scope.get(id.name);
+                            FuncValueType current_func = (FuncValueType) type;
+                            if (compare_functions(super_func, current_func)) 
+                                sym.put(name, type);
+                            else
+                                errors.semError(
+                                id, "Method overridden with different type signature: %s" + name);
+                        }
+                    }
+                    else
+                        sym.put(name, type);
+                } 
+            }
+        }
+        for (String super_sym : super_syms) 
+        {
+            if (sym.getDeclaredSymbols().contains(super_sym)==false)
+                sym.put(super_sym, super_scope.get(super_sym));
+        }
+        sym = sym.getParent();
+        current_class=null;
+        return cvt;
+    }
+    @Override
+    public Type analyze(VarDef node)
+    {
+        Type var_type = sym.get(node.var.identifier.name);
+        if (node.var.identifier.name!=current_class.className && var_type==null)
+            errors.semError(
+                node, "Cannot re-define attribute: %s", node.var.identifier.name);
+        return ValueType.annotationToValueType(node.var.type);
+    }
     @Override
-    public Type analyze(VarDef varDef) {
-        return ValueType.annotationToValueType(varDef.var.type);
+    public Type analyze(ListType node) 
+    {
+        return ValueType.annotationToValueType(node);
     }
 }