syntax.h

这是一个语法分析器 这是一个语法分析器

#ifndef SYNTAX_H_INCLUDED
#define SYNTAX_H_INCLUDED

#include "GLOBAL.H"
#include "STACK.H"
#include "SYN_LEX.H"
#include "ANALYSE_TABLE.H"

#define     STACKSIZE   512
#define     TOKENEND    -1
#define     DEALOK      0
#define     STREAMEND   -1

int current_token = 0;

FILE *testfp = NULL;
//int program[256] = {2, 7, 13, 1, 7, 15, 3, 7, 14, 11, 7, 25, 7, 37, 7, 45, 12, 18, 13, 14, 11, 1, 7, 45, 12, TOKENEND};
//int tptr = 0;

void next_token()
{
    int t;
    if (fscanf(testfp, "%d", &t) == EOF)
        current_token = TOKENEND;
    else
        current_token = t;
}

void push_produce(pstack head, int produce_id)
{
    struct sign_node *p = NULL;
    int sign_count = 0;
    int element = 0;
    pstack temp = NULL;
    new_stack(&temp, 256);
    p = sign[produce_id].next;
    while(p != NULL)
    {
        push(temp, p->id);
        sign_count++;
        p = p -> next;
    }
    while(sign_count > 0)
    {
        element = top(temp);
        pop(temp);
        if (push(head, element) != 0)
            error("stack full");
        sign_count--;
    }
    delete_stack(&temp);
}

int syn_error(pstack head)
{
    int top_sign = top(head);
    printf("***********************Error Syntax*******************\n");
    if (top_sign >= tcount)
    {
        while(follow_set[top_sign][current_token] != 1)
        {
            next_token();
            if(current_token == TOKENEND)
                return STREAMEND;
            printf("\"%s\" is skipped\n", sign_string[top_sign]);
        }
        printf("******************************************************\n");
    }
    else
    {
        pop(head);
        printf("\"%s\" is popped\n", sign_string[top_sign]);
        printf("******************************************************\n");
    }
    return DEALOK;
}

void output_produce(int produce_id)
{
    print_single_produce(stdout, produce_id);
}

void syntax()
{
    //int current_token = 0;
    int top_sign = TOKENEND + 1;
    pstack head = NULL;
    new_stack(&head, STACKSIZE);
    push(head, TOKENEND);
    push(head, tcount);
    next_token();
    do
    {
        top_sign = top(head);
        //current_token = get_current_token();
        if (top_sign == TOKENEND || top_sign < tcount)
        {
            if (top_sign == 0)
                pop(head);
            else if (top_sign == current_token)
            {
                if (top_sign > 0)
                    printf("-------------------->%s\n", sign_string[top_sign]);
                pop(head);
                next_token();
            }
            else
                if (syn_error(head) == STREAMEND)
                    break;
        }
        else
        {
            if (analyse_table[top_sign-tcount][current_token].next != NULL)
            {
                int produce_id = 0;
                pop(head);
                produce_id = analyse_table[top_sign-tcount][current_token].next->id;
                push_produce(head, produce_id);
                output_produce(produce_id);
            }
            else
                if (syn_error(head) == STREAMEND)
                    break;
        }
    } while(top_sign != TOKENEND);

    delete_stack(&head);
}

void test_syntax()
{
    testfp = fopen("..\\..\\token.txt", "rb+");
    if (testfp == NULL)
    {
        printf("open file fail!\n");
        return;
    }
    syntax();
    fclose(testfp);
}

#endif // SYNTAX_H_INCLUDED