Add syntax analyzer

parser.c

+#include<stdio.h>
+#include<string.h>
+#include<stdlib.h>
+#include"parser.h"
+
+Tree* A();
+Tree* A_(Tree * a_);
+Tree* E();
+Tree* E_(Tree * e_);
+Tree* T();
+Tree* T_(Tree * t_);
+Tree* F();
+Tree* F_();
+
+Tree* mkTree(TOKEN type,char*vl);
+
+int not_defined(TOKEN_LIST t[]);
+void match(int a);
+void syntax_error();
+void do_syntax_analysis();
+double cal(Tree* rtnode);
+void Free_tree(Tree* node);
+
+int s_error;
+int l;
+int index_location;
+
+void do_syntax_analysis()
+{
+    s_error = 0;
+    index_location = 0;
+    l = token_list[index_location].token;
+    Tree* root = A();
+    if(s_error == 1||index_location+1!=token_number)
+    {
+	printf("syntax error\n");
+	Free_tree(root);
+	return;
+    }
+    if(not_defined(token_list) == 1)
+    {
+	Free_tree(root);
+	return;
+    }
+    double result = cal(root);
+    if(result-(int)(result)==0)
+    {
+	printf("%d\n",(int)(result));
+    }
+    else
+    {
+	printf("%f\n",result);
+    }
+    Free_tree(root);
+    return;
+}
+
+Tree* A()
+{
+    if(l==1)
+    {
+//	printf("A->idA'\n");
+	Tree* temp1 = mkTree(token_list[index_location].token,token_list[index_location].value);
+	match(1);
+	return A_(temp1);
+    }
+    else if(l==9|l==2|l==3|l==5)
+    {
+//	printf("A->F'T'E'\n");
+	Tree* temp2;
+	temp2 = F_();
+	temp2 = T_(temp2);
+	return E_(temp2);
+    }
+    else
+    {
+	syntax_error();
+	return NULL;
+    }
+}
+
+Tree* A_(Tree* a_)
+{
+    if(l==4|l==5|l==6|l==7|l==0)
+    {
+//	printf("A'->T'E'\n");
+	a_ = T_(a_);
+	a_ = E_(a_);
+	return a_;
+    }
+    else if(l==8)
+    {
+//	printf("A'->=A\n");
+	Tree* temp3 = mkTree(token_list[index_location].token,token_list[index_location].value);
+	match(8);
+	temp3->left = a_;
+	temp3->right = A();
+	return temp3;
+    }
+
+    else
+    {
+	syntax_error();
+	return NULL;
+    }
+}
+
+Tree* E()
+{
+    if(l==1|l==9|l==2|l==3|l==5)
+    {
+//	printf("E->TE'\n");
+	Tree* temp15;
+	temp15 = T();
+	temp15 = E_(temp15);
+	return temp15;
+    }
+    else
+    {
+	syntax_error();
+	return NULL;
+    }
+}
+
+Tree* E_(Tree* e_)
+{
+    if(l==10|l==0)
+    {
+//	printf("E'->e\n");
+	match(0);
+	return e_;
+    }
+    else if(l==4)
+    {
+//	printf("E'->+TE'\n");
+	Tree* temp4 = mkTree(token_list[index_location].token,"+");
+	match(4);
+	temp4->left = e_;
+	temp4->right = T();
+	return E_(temp4);
+    }
+    else if(l==5)
+    {
+//	printf("E'->-TE'\n");
+	Tree *temp5 = mkTree(token_list[index_location].token,"-");
+	match(5);
+	temp5->left = e_;
+	temp5->right = T();
+	return E_(temp5);
+    }
+    else
+    {
+	syntax_error();
+	return NULL;
+    }
+}
+
+Tree* T()
+{
+    if(l==1|l==9|l==2|l==3|l==5)
+    {
+//	printf("T->FT'\n");
+	Tree* temp14;
+	temp14 = F();
+	temp14 = T_(temp14);
+	return temp14;
+    }
+    else
+    {
+	syntax_error();
+	return NULL;
+    }
+}
+
+Tree* T_(Tree *t_)
+{
+    if(l==10|l==5|l==4|l==0)
+    {
+//	printf("T'->e\n");
+	match(0);
+	return t_;
+    }
+    else if(l==6)
+    {
+//	printf("T'->*FT'\n");
+	Tree *temp6 = mkTree(token_list[index_location].token,"*");
+	match(6);
+	temp6 -> left = t_;
+	temp6 -> right = F();
+	return T_(temp6);
+    }
+    else if(l==7)
+    {
+//	printf("T'->/FT'\n");
+	Tree * temp7 = mkTree(token_list[index_location].token,"/");
+	match(7);
+	temp7 -> left = t_;
+	temp7 -> right = F();
+	return T_(temp7);
+    }
+    else
+    {
+	syntax_error();
+	return NULL;
+    }
+}
+
+Tree* F()
+{
+    if(l==1)
+    {
+//	printf("F->id\n");
+	Tree * temp8 = mkTree(token_list[index_location].token,token_list[index_location].value);
+	match(1);
+	return temp8;
+    }
+    else if(l==9|l==2|l==3|l==5)
+    {
+//	printf("F->F'\n");
+	return F_();
+    }
+    else
+    {
+	syntax_error();
+	return NULL;
+    }
+}
+
+Tree* F_()
+{
+    if(l==9)
+    {
+//	printf("F'->(E)\n");
+	Tree* temp12;
+	match(9);
+	temp12 = E();
+	match(10);
+	return temp12;
+    }
+    else if(l==2)
+    {
+//	printf("F'->int\n");
+	Tree* temp11 = mkTree(token_list[index_location].token,token_list[index_location].value);
+	match(2);
+	return temp11;
+    }
+    else if(l==3)
+    {
+//	printf("F'->Double\n");
+	Tree* temp13 = mkTree(token_list[index_location].token, token_list[index_location].value);
+	match(3);
+	return temp13;
+    }
+    else if(l==5)
+    {
+//	printf("F'->-F\n");
+	Tree* temp9 = mkTree(token_list[index_location].token,"-");
+	match(5);
+	temp9->left = F();
+	return temp9;
+    }
+    else
+    {
+	syntax_error();
+	return NULL;
+    }
+}
+
+Tree * mkTree(TOKEN type,char*vl)
+{
+    Tree * temp1 = (Tree*)malloc(sizeof(Tree));
+    temp1->left = NULL;
+    temp1->right = NULL;
+    temp1->token_type = type;
+    strcpy(temp1->token_value,vl);
+    return temp1;
+}
+void Free_tree(Tree * node)
+{
+    if(node!=NULL)
+    {
+	Free_tree(node->left);
+	Free_tree(node->right);
+	free(node);
+    }
+}
+
+void match(int look_ahd)
+{
+    if(look_ahd!=0)
+    {
+	if(look_ahd==token_list[index_location].token)
+	{
+	    index_location = index_location+1;
+	    l = token_list[index_location].token;
+	}
+	else
+	{
+	    syntax_error();
+	    return;
+	}
+    }
+}
+int not_defined(TOKEN_LIST t[])
+{
+    for(int i=0;i<token_number;i++)
+    {
+	if(t[i].token==1)
+	{
+	    if(t[i+1].token!=8&&symbol_table[find_symbol(t[i].value)].set_up==0)
+	    {
+		printf("%s is not defined\n",t[i].value);
+		return 1;
+	    }
+	}
+    }
+    return 0;
+}
+
+void syntax_error()
+{
+    s_error = 1;
+}
+
+double cal(Tree* rtnode)
+{
+    double temp_1,temp_2;
+    while(rtnode!=NULL)
+    {
+	if(rtnode->token_type == 1)
+	{
+	    return symbol_table[find_symbol(rtnode->token_value)].value.real_constant;
+	}
+	if(rtnode->token_type == 2)
+	{
+	    return atof(rtnode->token_value);
+	}
+	if(rtnode->token_type == 3)
+	{
+	    return atof(rtnode->token_value);
+	}
+	if(rtnode->token_type == 4)
+	{
+	    temp_1 = cal(rtnode->left);
+	    temp_2 = cal(rtnode->right);
+	    return temp_1+temp_2;
+	}
+	if(rtnode->token_type == 5)
+	{
+	    if(rtnode->left == NULL && rtnode->right == NULL)
+		break;
+	    if(rtnode->right == NULL)
+		return -cal(rtnode->left);
+	    else
+	    {
+		temp_1 = cal(rtnode->left);
+		temp_2 = cal(rtnode->right);
+		return temp_1 - temp_2;
+	    }
+	}
+	if(rtnode->token_type == 6)
+	{
+	    temp_1 = cal(rtnode->left);
+	    temp_2 = cal(rtnode->right);
+	    return temp_1*temp_2;
+	}
+	if(rtnode->token_type == 7)
+	{
+	    temp_1 = cal(rtnode->left);
+	    temp_2 = cal(rtnode->right);
+	    return temp_1 / temp_2;
+	}
+	if(rtnode->token_type == 8)
+	{
+    	    symbol_table[find_symbol(rtnode->left->token_value)].value.real_constant = cal(rtnode->right);
+	    symbol_table[find_symbol(rtnode->left->token_value)].set_up=1;
+	    return symbol_table[find_symbol(rtnode->left->token_value)].value.real_constant;
+	}
+    }
+}