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/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* parser.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: nahaddac <nahaddac@student.42.fr> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2020/06/17 18:09:04 by nahaddac #+# #+# */
/* Updated: 2020/10/06 11:22:14 by cacharle ### ########.fr */
/* */
/* ************************************************************************** */
/*
** \file parse.c
** \brief Parser
*/
#include "parser.h"
static char *g_sep_str_lookup[] = {
[TAG_END] = ";",
[TAG_AND] = "&&",
[TAG_OR] = "||",
[TAG_PIPE] = "|",
[TAG_REDIR_IN] = "<",
[TAG_REDIR_OUT] = ">",
[TAG_REDIR_APPEND] = ">>",
[TAG_PARENT_OPEN] = "(",
[TAG_PARENT_CLOSE] = ")",
};
/*
** push redirection token
** push while token is str and stick
** push last str token
*/
t_parsed *parse_redir(t_tok_lst *input, t_tok_lst **redirs)
{
tok_lst_push_back(redirs, tok_lst_uncons(&input));
if (input == NULL)
return (parsed_error("syntax error near unexpected token `newline'\n"));
// FIXME big condition could be avoided with lexer not putting STICK
// if the next tokens isn't a string
while (input != NULL
&& input->tag & TAG_IS_STR && input->tag & TAG_STICK
&& input->next != NULL && input->next->tag & TAG_IS_STR)
tok_lst_push_back(redirs, tok_lst_uncons(&input));
if (input == NULL)
return (NULL);
if (!(input->tag & TAG_IS_STR))
return (parsed_error("syntax error near unexpected token `%s'\n", input->content));
tok_lst_push_back(redirs, tok_lst_uncons(&input));
return (parsed_new(NULL, input));
}
t_parsed *parse_cmd(t_tok_lst *input)
{
t_ast *ast;
t_parsed *tmp;
if (input->tag & TAG_IS_SEP)
return (parsed_error("syntax error near unexpected token `%s'\n", input->content));
if ((ast = ast_new(AST_CMD)) == NULL)
return (NULL);
while (input != NULL)
{
if (input->tag & TAG_IS_STR)
tok_lst_push_back(&ast->cmd_argv, tok_lst_uncons(&input));
else if (input->tag & TAG_IS_REDIR)
{
tmp = parse_redir(input, &ast->redirs);
if (tmp == NULL || tmp->syntax_error)
return (tmp);
input = tmp->rest;
}
else
break;
}
return (parsed_new(ast, input));
}
t_parsed *parse_pipeline(t_tok_lst *input)
{
t_parsed *expr;
t_parsed *tail;
t_ast *expr_ast;
expr = parse_expr(input);
if (expr == NULL || expr->syntax_error ||
expr->rest == NULL || expr->rest->tag != TAG_PIPE)
return (expr);
tail = parse_pipeline(expr->rest->next);
if (tail == NULL || tail->syntax_error)
return (tail);
expr_ast = expr->ast;
free(expr);
t_ast *pipeline_ast;
if (tail->ast->tag == AST_CMD)
{
pipeline_ast = ast_new(AST_PIPELINE);
if ((pipeline_ast->pipeline = ft_lstnew(tail->ast)) == NULL)
{
/* ast_destroy(expr_ast); */
/* ft_lstdestroy(&tail, NULL); */
return (NULL);
}
}
else
pipeline_ast = tail->ast;
if (ft_lstpush_front_node(&pipeline_ast->pipeline, expr_ast) == NULL)
{
/* ast_destroy(expr_ast); */
/* ft_lstdestroy(&tail, NULL); */
return (NULL);
}
return (parsed_new(pipeline_ast, tail->rest));
}
/*
** parse and operation (| ; && ||)
*/
t_parsed *parse_op(t_tok_lst *input)
{
t_ast *ast;
t_parsed *left;
t_parsed *right;
enum e_tok sep_tag;
left = parse_pipeline(input);
if (left == NULL || left->syntax_error)
return (left);
input = left->rest;
if (input == NULL || input->tag & TAG_PARENT_CLOSE)
return (left);
sep_tag = input->tag;
if (!(sep_tag & TAG_IS_SEP))
return (parsed_error("syntax error near unexpected token `%s'\n",
g_sep_str_lookup[sep_tag]));
ft_lstpop_front((t_ftlst**)&input, free);
if (input == NULL && sep_tag == TAG_END)
return (left);
if (input == NULL)
return (parsed_error("syntax error expected token\n"));
right = parse_op(input);
if (right == NULL || right->syntax_error)
return (right);
if ((ast = ast_new(AST_OP)) == NULL)
return (NULL);
ast->op.left = left->ast;
ast->op.right = right->ast;
ast->op.sep = sep_tag;
free(left);
left = parsed_new(ast, right->rest);
free(right);
return (left);
}
/*
** try to parse parenthesis, if fail parse a command.
** parenthesis can be followed by redirections
*/
t_parsed *parse_expr(t_tok_lst *input)
{
t_parsed *parsed;
t_parsed *tmp;
t_ast *ast;
if (input->tag & TAG_PARENT_OPEN)
{
if (!(parsed = parse_op(input->next)) || parsed->syntax_error)
return (parsed);
input = parsed->rest;
if (input == NULL || !(input->tag & TAG_PARENT_CLOSE))
return (parsed_error("syntax error expected token\n"));
input = input->next;
if ((ast = ast_new(AST_PARENT)) == NULL)
return (NULL);
ast->parent_ast = parsed->ast;
parsed->ast = ast;
while (input != NULL && input->tag & TAG_IS_REDIR)
{
tmp = parse_redir(input, &parsed->ast->redirs);
if (tmp == NULL || tmp->syntax_error)
return (tmp);
input = tmp->rest;
}
parsed->rest = input;
return (parsed);
}
return (parse_cmd(input));
}
t_parsed *parse(t_tok_lst *input)
{
if (input == NULL)
return (NULL);
return (parse_op(input));
}
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