First commit

Signed-off-by: Mattias Andrée <maandree@kth.se>

7 files changed, 378 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..40c3059
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,15 @@
+*\#*
+*~
+*.o
+*.a
+*.lo
+*.su
+*.so
+*.so.*
+*.dll
+*.dylib
+*.gch
+*.gcov
+*.gcno
+*.gcda
+/makelint
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..c44b2d9
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,15 @@
+ISC License
+
+© 2021 Mattias Andrée <maandree@kth.se>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..e67e73d
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,39 @@
+.POSIX:
+
+CONFIGFILE = config.mk
+include $(CONFIGFILE)
+
+OBJ =\
+	makelint.o\
+	ui.o
+
+HDR =\
+	common.h
+
+all: makelint
+$(OBJ): $(HDR)
+
+.c.o:
+	$(CC) -c -o $@ $< $(CFLAGS) $(CPPFLAGS)
+
+makelint: $(OBJ)
+	$(CC) -o $@ $(OBJ) $(LDFLAGS)
+
+install: makelint
+	mkdir -p -- "$(DESTDIR)$(PREFIX)/bin"
+	mkdir -p -- "$(DESTDIR)$(MANPREFIX)/man1/"
+	cp -- makelint "$(DESTDIR)$(PREFIX)/bin/"
+	cp -- makelint.1 "$(DESTDIR)$(MANPREFIX)/man1/"
+
+uninstall:
+	-rm -f -- "$(DESTDIR)$(PREFIX)/bin/makelint"
+	-rm -f -- "$(DESTDIR)$(MANPREFIX)/man1/makelint.1"
+
+clean:
+	-rm -f -- *.o *.a *.lo *.su *.so *.so.* *.gch *.gcov *.gcno *.gcda
+	-rm -f -- makelint
+
+.SUFFIXES:
+.SUFFIXES: .o .c
+
+.PHONY: all install uninstall clean
diff --git a/common.h b/common.h
new file mode 100644
index 0000000..b2d0a4e
--- /dev/null
+++ b/common.h
@@ -0,0 +1,57 @@
+/* See LICENSE file for copyright and license details. */
+#include <libsimple.h>
+#include <libsimple-arg.h>
+
+#define EXIT_STYLE         1
+#define EXIT_WARNING       2
+#define EXIT_UNSPECIFIED   3
+#define EXIT_NONCONFIRMING 4
+#define EXIT_UNDEFINED     5
+#define EXIT_CRITICAL      6
+#define EXIT_ERROR         7
+
+
+#define LIST_WARNING_CLASSES(X)\
+	X(WC_MAKEFILE, "makefile", INFORM)\
+	X(WC_EXTRA_MAKEFILE, "extra-makefile", WARN)\
+	X(WC_CMDLINE, "cmdline", WARN)\
+	X(WC_TEXT, "text", WARN)
+
+
+enum action {
+	IGNORE,
+	INFORM,
+	WARN
+};
+
+enum warning_class {
+#define X(ENUM, NAME, ACTION) ENUM,
+	LIST_WARNING_CLASSES(X)
+#undef X
+	NUM_WARNING_CLASS
+};
+
+struct warning_class_data {
+	const char *name;
+	enum action action;
+};
+
+struct line {
+	char *data;
+	size_t len;
+	const char *path;
+	size_t lineno;
+};
+
+
+extern int exit_status;
+
+
+/* ui.c */
+extern struct warning_class_data warning_classes[];
+void xprintwarningf(enum warning_class class, int severity, const char *fmt, ...);
+#define printinfof(CLASS, ...) xprintwarningf(CLASS, EXIT_STYLE, __VA_ARGS__)
+#define warnf_warning(CLASS, ...) xprintwarningf(CLASS, EXIT_WARNING, __VA_ARGS__)
+#define warnf_unspecified(CLASS, ...) xprintwarningf(CLASS, EXIT_UNSPECIFIED, __VA_ARGS__)
+#define warnf_undefined(CLASS, ...) xprintwarningf(CLASS, EXIT_UNDEFINED, __VA_ARGS__)
+void printerrorf(const char *fmt, ...);
diff --git a/config.mk b/config.mk
new file mode 100644
index 0000000..d354a28
--- /dev/null
+++ b/config.mk
@@ -0,0 +1,8 @@
+PREFIX    = /usr
+MANPREFIX = $(PREFIX)/share/man
+
+CC = cc
+
+CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_XOPEN_SOURCE=700 -D_GNU_SOURCE
+CFLAGS   = -std=c99 -Wall -g
+LDFLAGS  = -lsimple
diff --git a/makelint.c b/makelint.c
new file mode 100644
index 0000000..45f599a
--- /dev/null
+++ b/makelint.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 "
+			                         "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;
+}
diff --git a/ui.c b/ui.c
new file mode 100644
index 0000000..e23916e
--- /dev/null
+++ b/ui.c
@@ -0,0 +1,47 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+struct warning_class_data warning_classes[] = {
+#define X(ENUM, NAME, ACTION) {NAME, ACTION},
+	LIST_WARNING_CLASSES(X)
+#undef X
+	{NULL, 0}
+};
+
+
+static void
+vxprintwarningf(enum warning_class class, int severity, const char *fmt, va_list ap)
+{
+	if (warning_classes[class].action != IGNORE) {
+		fprintf(stderr, "%s: [%s] ", argv0,
+		        warning_classes[class].action == INFORM ? "info" : "warn");
+		vfprintf(stderr, fmt, ap);
+		fprintf(stderr, " (-w%s)\n", warning_classes[class].name);
+		if (warning_classes[class].action != INFORM)
+			exit_status = MAX(exit_status, severity);
+	}
+}
+
+
+void
+xprintwarningf(enum warning_class class, int severity, const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	vxprintwarningf(class, severity, fmt, ap);
+	va_end(ap);
+}
+
+
+void
+printerrorf(const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	fprintf(stderr, "%s: [error] ", argv0);
+	vfprintf(stderr, fmt, ap);
+	fprintf(stderr, "\n");
+	va_end(ap);
+	exit(EXIT_CRITICAL);
+}