ccanlint: -k should not pollute module directory.

It leads to numerous problems, such as the next ccanlint getting confused
trying to compile examples, and "-k examples_compile -k examples_exist"
giving bogus errors.

So instead we leave the temporary dir lying around and delete
individual files which aren't marked "keep".

tools/ccanlint/ccanlint.c

@@ -292,12 +292,21 @@ static void init_tests(void)
 	}
 }
 
+static int show_tmpdir(char *dir)
+{
+	printf("You can find ccanlint working files in '%s'\n", dir);
+	return 0;
+}
+
 static char *keep_test(const char *testname, void *unused)
 {
 	struct ccanlint *i = find_test(testname);
 	if (!i)
 		errx(1, "No test %s to --keep", testname);
 	i->keep_results = true;
+
+	/* Don't automatically destroy temporary dir. */
+	talloc_set_destructor(temp_dir(NULL), show_tmpdir);
 	return NULL;
 }
 
@@ -495,6 +504,10 @@ int main(int argc, char *argv[])
 			   " of CCAN modules.",
 			   "This usage message");
 
+	/* We move into temporary directory, so gcov dumps its files there. */
+	if (chdir(temp_dir(talloc_autofree_context())) != 0)
+		err(1, "Error changing to %s temporary dir", temp_dir(NULL));
+
 	opt_parse(&argc, argv, opt_log_stderr_exit);
 
 	if (dir[0] != '/')
@@ -508,10 +521,6 @@ int main(int argc, char *argv[])
 	if (verbose >= 4)
 		tools_verbose = true;
 
-	/* We move into temporary directory, so gcov dumps its files there. */
-	if (chdir(temp_dir(talloc_autofree_context())) != 0)
-		err(1, "Error changing to %s temporary dir", temp_dir(NULL));
-
 	m = get_manifest(talloc_autofree_context(), dir);
 
 	/* Create a symlink from temp dir back to src dir's test directory. */

tools/ccanlint/tests/examples_compile.c

@@ -122,6 +122,9 @@ static bool compile(const void *ctx,
 	if (!compile_and_link(ctx, file->fullname, ccan_dir,
 			      obj_list(m, file),
 			      "", lib_list(m), file->compiled, output)) {
+		/* Don't keep failures. */
+		if (keep)
+			unlink(file->compiled);
 		talloc_free(file->compiled);
 		file->compiled = NULL;
 		return false;

tools/ccanlint/tests/tests_coverage.c

@@ -127,15 +127,26 @@ static void do_run_coverage_tests(struct manifest *m,
 				  unsigned int *timeleft, struct score *score)
 {
 	struct ccan_file *i;
-	char *cmdout;
+	char *cmdout, *outdir;
 	char *covcmd;
 	bool full_gcov = (verbose > 1);
 	struct list_head *list;
 
 	/* This tells gcov where we put those .gcno files. */
+	outdir = talloc_dirname(score, m->info_file->compiled);
 	covcmd = talloc_asprintf(m, "gcov %s -o %s",
 				 full_gcov ? "" : "-n",
-				 talloc_dirname(score, m->info_file->compiled));
+				 outdir);
+
+	/* Unlink these files afterwards. */
+	if (!keep) {
+		talloc_set_destructor(talloc_asprintf(score,
+						      "%s/run.gcno", outdir),
+				      unlink_file_destructor);
+		talloc_set_destructor(talloc_asprintf(score,
+						      "%s/run.gcda", outdir),
+				      unlink_file_destructor);
+	}
 
 	/* Run them all. */
 	foreach_ptr(list, &m->run_tests, &m->api_tests) {

tools/tools.c

@@ -210,6 +210,12 @@ char *temp_dir(const void *ctx)
 	return tmpdir;
 }
 
+int unlink_file_destructor(char *filename)
+{
+	unlink(filename);
+	return 0;
+}
+
 char *maybe_temp_file(const void *ctx, const char *extension, bool keep,
 		      const char *srcname)
 {
@@ -218,11 +224,7 @@ char *maybe_temp_file(const void *ctx, const char *extension, bool keep,
 	struct stat st;
 	unsigned int count = 0;
 
-	if (!keep)
 	srcname = talloc_basename(ctx, srcname);
-	else
-		assert(srcname[0] == '/');
-
 	if (strrchr(srcname, '.'))
 		baselen = strrchr(srcname, '.') - srcname;
 	else
@@ -230,7 +232,7 @@ char *maybe_temp_file(const void *ctx, const char *extension, bool keep,
 
 	do {
 		f = talloc_asprintf(ctx, "%s/%.*s%s%s",
-				    keep ? "" : temp_dir(ctx),
+				    temp_dir(ctx),
 				    baselen, srcname,
 				    suffix, extension);
 		talloc_free(suffix);
@@ -238,7 +240,10 @@ char *maybe_temp_file(const void *ctx, const char *extension, bool keep,
 	} while (lstat(f, &st) == 0);
 
 	if (tools_verbose)
-		printf("Creating file %s\n", f);
+		printf("Creating %sfile %s\n", keep ? "" : "temporary ", f);
+
+	if (!keep)
+		talloc_set_destructor(f, unlink_file_destructor);
 
 	talloc_free(suffix);
 	return f;

tools/tools.h

@@ -72,4 +72,7 @@ char *maybe_temp_file(const void *ctx, const char *extension, bool in_pwd,
 /* Default wait for run_command.  Should never time out. */
 extern const unsigned int default_timeout_ms;
 
+/* Talloc destructor which unlinks file. */
+int unlink_file_destructor(char *filename);
+
 #endif /* CCAN_TOOLS_H */