diff options
Diffstat (limited to 'mklint.c')
| -rw-r--r-- | mklint.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/mklint.c b/mklint.c new file mode 100644 index 0000000..aec636e --- /dev/null +++ b/mklint.c @@ -0,0 +1,197 @@ +/* See LICENSE file for copyright and license details. */ +#include "common.h" + +NUSAGE(EXIT_ERROR, "[-f makefile]"); + + + +int exit_status = 0; + +static const char *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 < ELEMSOF(default_makefiles); i++) + if (!access(default_makefiles[i], F_OK)) + warnf_warning(WC_EXTRA_MAKEFILE, "found additional standard makefile: %s", *pathp); + + 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; +} |