/* See LICENSE file for copyright and license details. */
#include "common.h"
NUSAGE(EXIT_ERROR, "[-f makefile]");
int exit_status = 0;
static const char *const default_makefiles[] = {
"makefile",
"Makefile"
};
static int
open_default_makefile(const char **pathp)
{
int fd;
size_t i;
/* The specification says that the alternatives “shall be
* tried”, but it uses the phrase “if neither … are found”,
* implying that make(1) shall fail if a file cannot be
* opened and only try the next alternative if it failed
* becomes the file does not exist.
*/
for (i = 0; i < ELEMSOF(default_makefiles); i++) {
*pathp = default_makefiles[i];
fd = open(*pathp, O_RDONLY);
if (fd >= 0) {
printinfof(WC_MAKEFILE, "found standard makefile to use: %s", *pathp);
goto find_existing_fallbacks;
} else if (errno != ENOENT) {
eprintf("found standard makefile to use, but failed to open: %s:", *pathp);
}
}
printerrorf("couldn't find any makefile to use, portable "
"alternatives are ./makefile and ./Makefile");
find_existing_fallbacks:
for (i++; i < ELEMSOF(default_makefiles); i++)
if (!access(default_makefiles[i], F_OK))
warnf_warning(WC_EXTRA_MAKEFILE, "found additional standard makefile: %s",
default_makefiles[i]);
return fd;
}
static void
cmdline_opt_f(const char *arg, const char **makefile_pathp)
{
static int warning_emitted = 0;
if (*makefile_pathp && !warning_emitted) {
warning_emitted = 1;
warnf_unspecified(WC_CMDLINE, "the -f option has been specified multiple times, "
"they are processed in order, but the behaviour is "
"otherwise unspecified");
printinfof(WC_CMDLINE, "this implementation will use the last "
"option and discard earlier options");
}
*makefile_pathp = arg;
}
static struct line *
load_file(int fd, const char *fname, size_t *nlinesp)
{
struct line *lines;
char *buf = NULL, *p;
size_t size = 0;
size_t len = 0;
size_t i;
ssize_t r;
/* getline(3) may seem like the best way to read line by line,
* however, it may terminate before the end of the line is
* reached, which we would have to deal with, additionally,
* we want to check for null bytes. Therefore we will keep
* this simple and use read(3) and scan manually; and as a
* bonus we can leave the file descriptor open, and let the
* caller than created it close it.
*/
i = 0;
*nlinesp = 0;
for (;;) {
if (len == size)
buf = erealloc(buf, size += 2048);
r = read(fd, &buf[len], size - len);
if (r > 0)
len += (size_t)r;
else if (!r)
break;
else if (errno == EINTR)
continue;
else
eprintf("read %s:", fname);
for (; i < len; i++) {
if (buf[i] == '\n') {
*nlinesp += 1;
buf[i] = '\0';
} else if (buf[i] == '\0') {
/* https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_403 */
warnf_undefined(WC_TEXT, "%s:%zu: file contains a NUL byte, this is disallowed, because "
"input files are text files, and causes undefined behaviour",
fname, *nlinesp + 1);
/* make(1) should probably just abort */
printinfof(WC_TEXT, "this implementation will replace it with a <space>");
buf[i] = ' ';
}
}
}
if (len && buf[len - 1] != '\0') { /* LF has been converted to NUL above */
/* https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_403 */
warnf_undefined(WC_TEXT, "%s:%zu: is non-empty but does not end with a <newline>, which is "
"required because input files are text files, and omission of it "
"causes undefined behaviour",
fname, *nlinesp + 1);
/* make(1) should probably just abort */
printinfof(WC_TEXT, "this implementation will add the missing <newline>");
buf = erealloc(buf, len + 1);
buf[len++] = '\0';
*nlinesp += 1;
}
lines = *nlinesp ? ecalloc(*nlinesp, sizeof(*lines)) : NULL;
for (p = buf, i = 0; i < *nlinesp; i++) {
lines[i].lineno = i + 1;
lines[i].path = fname;
lines[i].len = strlen(p);
lines[i].data = ememdup(p, lines[i].len + 1);
if (lines[i].len + 1 > 2048) {
/* https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_403 */
warnf_undefined(WC_TEXT, "%s:%zu: line is, including the <newline> character, longer than "
"2048 bytes which causes undefined behaviour as input files are "
"text files and POSIX only guarantees support for lines up to 2048 "
"bytes long including the <newline> character in text files",
fname, *nlinesp + 1);
}
p += lines[i].len + 1;
}
free(buf);
return lines;
}
int
main(int argc, char *argv[])
{
const char *path = NULL;
int fd;
struct line *lines;
size_t nlines;
libsimple_default_failure_exit = EXIT_ERROR;
/* make(1) shall support mixing of options and operands (uptil --) */
ARGBEGIN {
case 'f':
cmdline_opt_f(ARG(), &path);
break;
default:
usage();
} ARGEND;
if (argc)
usage();
if (!path) {
fd = open_default_makefile(&path);
} else if (!strcmp(path, "-")) {
/* “A pathname of '-' shall denote the standard input” */
fd = dup(STDIN_FILENO);
if (fd < 0)
eprintf("dup <stdin>:");
path = "<stdin>";
} else {
fd = open(path, O_RDONLY);
if (fd < 0)
eprintf("open %s O_RDONLY:", path);
}
lines = load_file(fd, path, &nlines);
close(fd);
free(lines);
return exit_status;
}
