42sh/src/utils/ast/ast.c

#define _POSIX_C_SOURCE 200809L
#include "ast.h"

#include <assert.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>

void ast_free(struct ast **node)
{
    if (node == NULL || *node == NULL)
        return;
    // ast void does not need to be freed.
    if (ast_is_if(*node))
        ast_free_if(ast_get_if(*node));
    else if (ast_is_command(*node))
        ast_free_command(ast_get_command(*node));
    else if (ast_is_list(*node))
        ast_free_list(ast_get_list(*node));
    else if (ast_is_and_or(*node))
        ast_free_and_or(ast_get_and_or(*node));
    else if (ast_is_redir(*node))
        ast_free_redir(ast_get_redir(*node));

    free(*node);
    *node = NULL;
}

struct ast *ast_create(enum ast_type type, void *data)
{
    struct ast *node = malloc(sizeof(struct ast));
    if (!node)
        return NULL;

    node->type = type;
    node->data = data;

    return node;
}

static void ast_print_dot_recursive(struct ast *node, FILE *out)
{
    if (!node)
        return;

    switch (node->type)
    {
    case AST_LIST: {
        struct ast_list *ast_list = ast_get_list(node);
        fprintf(out, "  node%p [label=\"LIST\"];\n", (void *)node);

        struct list *elt = ast_list->children;
        while (elt != NULL)
        {
            struct ast *child = (struct ast *)elt->data;
            fprintf(out, "  node%p -> node%p;\n", (void *)node, (void *)child);
            ast_print_dot_recursive(child, out);
            elt = elt->next;
        }
        break;
    }
    case AST_IF: {
        struct ast_if *if_data = ast_get_if(node);
        fprintf(out, "  node%p [label=\"IF\"];\n", (void *)node);

        if (if_data->condition)
        {
            fprintf(out, "  node%p -> node%p;\n", (void *)node,
                    (void *)if_data->condition);
            fprintf(out,
                    "  node%p [fillcolor=\"lightyellow\", style=\"filled\"];\n",
                    (void *)if_data->condition);
            ast_print_dot_recursive(if_data->condition, out);

            if (if_data->then_clause)
            {
                fprintf(out, "  node%p -> node%p [label=\"true\"];\n",
                        (void *)if_data->condition,
                        (void *)if_data->then_clause);
                ast_print_dot_recursive(if_data->then_clause, out);
            }

            if (if_data->else_clause)
            {
                fprintf(out, "  node%p -> node%p [label=\"false\"];\n",
                        (void *)if_data->condition,
                        (void *)if_data->else_clause);
                ast_print_dot_recursive(if_data->else_clause, out);
            }
        }
        break;
    }
    case AST_CMD: {
        struct ast_command *command_data = ast_get_command(node);
        fprintf(out, "  node%p [label=\"", (void *)node);
        struct list *l = command_data->command;
        while (l)
        {
            fprintf(out, "%s", (char *)l->data);
            if (l->next)
                fprintf(out, " ");
            l = l->next;
        }
        fprintf(out, "\"];\n");
        break;
    }
    case AST_END:
        fprintf(out, "  node%p [label=\"END\"];\n", (void *)node);
        break;
    default:
        break;
    }
}

void ast_print_dot(struct ast *ast)
{
    if (!ast)
        return;

    FILE *dot_pipe = popen("dot -Tsvg -o ast.svg", "w");
    if (!dot_pipe)
    {
        return;
    }

    fprintf(dot_pipe, "digraph AST {\n");
    ast_print_dot_recursive(ast, dot_pipe);
    fprintf(dot_pipe, "}\n");
    pclose(dot_pipe);
}