ccanlint: objects_build_with_stringchecks

If we detect any mention of a problematic string function, try compiling
the entire module with string debugging enabled.

tools/ccanlint/tests/objects_build_with_stringchecks.c

+#include <tools/ccanlint/ccanlint.h>
+#include <tools/tools.h>
+#include <ccan/talloc/talloc.h>
+#include <ccan/str/str.h>
+#include <ccan/str_talloc/str_talloc.h>
+#include <ccan/foreach/foreach.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <limits.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <err.h>
+#include <string.h>
+#include <ctype.h>
+#include "reduce_features.h"
+
+static const char *uses_stringfuncs(struct manifest *m)
+{
+	struct list_head *list;
+
+	foreach_ptr(list, &m->c_files, &m->h_files) {
+		struct ccan_file *i;
+		char *match;
+
+		list_for_each(list, i, list) {
+			if (strreg(m, get_ccan_file_contents(i),
+				   "(isalnum|isalpha|isascii|isblank|iscntrl"
+				   "|isdigit|isgraph|islower|isprint|ispunct"
+				   "|isspace|isupper|isxdigit"
+				   "|strstr|strchr|strrchr)", &match)) {
+				if (verbose > 2)
+					printf("Matched '%s' in %s\n",
+					       match, i->fullname);
+				return NULL;
+			}
+		}
+	}
+	return "No ctype.h or string functions found";
+}
+
+static void write_str(int fd, const char *str)
+{
+	if (write(fd, str, strlen(str)) != strlen(str))
+		err(1, "Writing to temporary file");
+}
+
+static int start_file(const char *filename)
+{
+	int fd;
+	fd = open(filename, O_WRONLY|O_CREAT, 0600);
+	write_str(fd, "#define CCAN_STR_DEBUG 1\n#include <ccan/str/str.h>\n");
+	return fd;
+}
+
+static void test_compile(struct score *score,
+			 struct ccan_file *file,
+			 const char *filename,
+			 bool keep,
+			 const char *flags,
+			 bool *errors,
+			 bool *warnings)
+{
+	char *output, *compiled;
+
+	compiled = maybe_temp_file(score, "", keep, filename);
+	if (!compile_object(score, filename, ccan_dir, compiler, flags,
+			    compiled, &output)) {
+		score_file_error(score, file, 0,
+				 "Compiling object files:\n%s",
+				 output);
+		*errors = true;
+	} else if (!streq(output, "")) {
+		score_file_error(score, file, 0,
+				 "Compiling object files gave warnings:\n%s",
+				 output);
+		*warnings = true;
+	}
+}
+
+static struct ccan_file *get_main_header(struct manifest *m)
+{
+	struct ccan_file *f;
+
+	list_for_each(&m->h_files, f, list) {
+		if (strstarts(f->name, m->basename)
+		    && strlen(f->name) == strlen(m->basename) + 2) {
+			return f;
+		}
+	}
+	/* Should not happen, since we passed main_header_exists! */
+	errx(1, "No main header?");
+}
+
+static void build_objects_with_stringchecks(struct manifest *m,
+					    bool keep, unsigned int *timeleft,
+					    struct score *score)
+{
+	struct ccan_file *i;
+	bool errors = false, warnings = false;
+	char *tmp, *flags;
+	int tmpfd;
+
+	/* FIXME:: We need -I so local #includes work outside normal dir. */
+	flags = talloc_asprintf(score, "-I%s %s", m->dir, cflags);
+
+	/* Won't work into macros, but will get inline functions. */
+	if (list_empty(&m->c_files)) {
+		char *line;
+		i = get_main_header(m);
+		tmp = maybe_temp_file(score, ".c", keep, i->fullname);
+		tmpfd = start_file(tmp);
+		line = talloc_asprintf(score, "#include <ccan/%s/%s.h>\n",
+				       m->basename, m->basename);
+		write_str(tmpfd, line);
+		close(tmpfd);
+		test_compile(score, i, tmp, keep, flags, &errors, &warnings);
+	} else {
+		list_for_each(&m->c_files, i, list) {
+			tmp = maybe_temp_file(score, ".c", keep, i->fullname);
+			tmpfd = start_file(tmp);
+			write_str(tmpfd, get_ccan_file_contents(i));
+			close(tmpfd);
+			test_compile(score, i, tmp, keep, flags,
+				     &errors, &warnings);
+		}
+	}
+
+	score->total = 1;
+	if (!errors) {
+		score->pass = true;
+		score->score = !warnings;
+	}
+}
+
+struct ccanlint objects_build_with_stringchecks = {
+	.key = "objects_build_with_stringchecks",
+	.name = "Module compiles with extra ctype.h and str function checks",
+	.check = build_objects_with_stringchecks,
+	.can_run = uses_stringfuncs,
+	.needs = "objects_build main_header_exists"
+};
+REGISTER_TEST(objects_build_with_stringchecks);