/*******************************************************************/

/*  slibtool: a skinny libtool implementation, written in C        */

/*  Copyright (C) 2016  Z. Gilboa                                  */

/*  Released under the Standard MIT License; see COPYING.SLIBTOOL. */

/*******************************************************************/

#include <stdio.h>

#include <limits.h>

#include <unistd.h>

#include <fcntl.h>

#include <string.h>

#include <stdlib.h>

#include <stdbool.h>

#include <sys/wait.h>

#include <slibtool/slibtool.h>

#include "slibtool_spawn_impl.h"

static void slbt_dump_machine_child(

	char *	program,

	int	fd[2])

{

	char *	compiler;

	char *	argv[3];

	if ((compiler = strchr(program,'/')))

		compiler++;

	else

		compiler = program;

	argv[0] = compiler;

	argv[1] = "-dumpmachine";

	argv[2] = 0;

	close(fd[0]);

	close(0);

	close(1);

	if ((fd[0] = open("/dev/null",O_RDONLY)))

		exit(EXIT_FAILURE);

	if (dup(fd[1]) == 1)

		execvp(program,argv);

	exit(EXIT_FAILURE);

}

int slbt_dump_machine(

	const char *	compiler,

	char *		machine,

	size_t		bufsize)

{

	pid_t	pid;

	pid_t	rpid;

	int	code;

	int	fd[2];

	FILE *	fmachine;

	char *	newline;

	char	check[2];

	char	program[PATH_MAX];

	if (!machine || !bufsize)

		return -1;

	if ((size_t)snprintf(program,sizeof(program),"%s",

			compiler) >= sizeof(program))

		return -1;

	if (pipe(fd))

		return -1;

	if ((pid = fork()) < 0) {

		close(fd[0]);

		close(fd[1]);

		return -1;

	}

	if (pid == 0)

		slbt_dump_machine_child(

			program,

			fd);

	rpid = waitpid(

		pid,

		&code,

		0);

	if ((rpid != pid) || code) {

		close(fd[0]);

		close(fd[1]);

		return -1;

	}

	if ((fmachine = fdopen(fd[0],"r"))) {

		close(fd[1]);

		newline = 0;

		if (fgets(machine,bufsize,fmachine) == machine)

			if (!fgets(check,sizeof(check),fmachine))

				if (feof(fmachine))

					if ((newline = strrchr(machine,'\n')))

						*newline = 0;

		fclose(fmachine);

	} else {

		newline = 0;

		close(fd[0]);

		close(fd[1]);

	}

	return newline ? 0 : -1;

}