lib/igt_kmod: add compatibility for KUnit

This adds functions for both executing the tests as well as parsing (K)TAP
kmsg output, as per the KTAP spec [1].

[1] https://www.kernel.org/doc/html/latest/dev-tools/ktap.html

v1 -> v2:
- refactor igt_kunit function and ktap parser so that we have only one
  parser that we call only once (code size is now less than half the
  size as v1)
- add lookup_value helper
- fix parsing problems
v2 -> v3:
- move ktap parsing functions to own file
- rename to ktap_parser
- get rid of unneeded pointers in igt_kunit
- change return values to allow for subsequent call to igt_kselftests if
  needed
- add docs to parsing functions and helpers
- switch to line buffering
- add line buffering logging helper
- fix kunit module handling
- fix parsing of version lines
- use igt_subtest blocks to improve output handling on the CI
- fix output handling during crashes

Signed-off-by: Isabella Basso <isabbasso@riseup.net>

v3 -> v4:
- handle igt_ktap_parser fail with IGT_EXIT_ABORT code

v4 -> v5:
- added missing newlines in igt_warn
- removed setvbuf

Signed-off-by: Dominik Karol Piątkowski <dominik.karol.piatkowski@intel.com>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

1 files changed, 334 insertions, 0 deletions

diff --git a/lib/igt_ktap.c b/lib/igt_ktap.c
new file mode 100644
index 000000000..117598faa
--- /dev/null
+++ b/lib/igt_ktap.c
@@ -0,0 +1,334 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Isabella Basso do Amaral <isabbasso@riseup.net>
+ */
+
+#include <ctype.h>
+#include <limits.h>
+
+#include "igt_aux.h"
+#include "igt_core.h"
+#include "igt_ktap.h"
+
+static int log_to_end(enum igt_log_level level, FILE *f,
+		      char *record, const char *format, ...) __attribute__((format(printf, 4, 5)));
+
+/**
+ * log_to_end:
+ * @level: #igt_log_level
+ * @record: record to store the read data
+ * @format: format string
+ * @...: optional arguments used in the format string
+ *
+ * This is an altered version of the generic structured logging helper function
+ * igt_log capable of reading to the end of a given line.
+ *
+ * Returns: 0 for success, or -2 if there's an error reading from the file
+ */
+static int log_to_end(enum igt_log_level level, FILE *f,
+		      char *record, const char *format, ...)
+{
+	va_list args;
+	const char *lend;
+
+	va_start(args, format);
+	igt_vlog(IGT_LOG_DOMAIN, level, format, args);
+	va_end(args);
+
+	lend = strchrnul(record, '\n');
+	while (*lend == '\0') {
+		igt_log(IGT_LOG_DOMAIN, level, "%s", record);
+		if (fgets(record, BUF_LEN, f) == NULL) {
+			igt_warn("kmsg truncated: unknown error (%m)\n");
+			return -2;
+		}
+		lend = strchrnul(record, '\n');
+	}
+	return 0;
+}
+
+/**
+ * lookup_value:
+ * @haystack: the string to search in
+ * @needle: the string to search for
+ *
+ * Returns: the value of the needle in the haystack, or -1 if not found.
+ */
+static long lookup_value(const char *haystack, const char *needle)
+{
+	const char *needle_rptr;
+	char *needle_end;
+	long num;
+
+	needle_rptr = strcasestr(haystack, needle);
+
+	if (needle_rptr == NULL)
+		return -1;
+
+	/* skip search string and whitespaces after it */
+	needle_rptr += strlen(needle);
+
+	num = strtol(needle_rptr, &needle_end, 10);
+
+	if (needle_rptr == needle_end)
+		return -1;
+
+	if (num == LONG_MIN || num == LONG_MAX)
+		return 0;
+
+	return num > 0 ? num : 0;
+}
+
+/**
+ * find_next_tap_subtest:
+ * @fp: FILE pointer
+ * @record: buffer used to read fp
+ * @is_builtin: whether KUnit is built-in or not
+ *
+ * Returns:
+ * 0 if there's missing information
+ * -1 if not found
+ * -2 if there are problems while reading the file.
+ * any other value corresponds to the amount of cases of the next (sub)test
+ */
+static int find_next_tap_subtest(FILE *fp, char *record, bool is_builtin)
+{
+	const char *test_lookup_str, *subtest_lookup_str, *name_rptr, *version_rptr;
+	char test_name[BUF_LEN + 1];
+	long test_count;
+
+	test_name[0] = '\0';
+	test_name[BUF_LEN] = '\0';
+
+	test_lookup_str = " subtest: ";
+	subtest_lookup_str = " test: ";
+
+	/*
+	 * "(K)TAP version XX" should be the first line on all (sub)tests as per
+	 * https://kernel.org/doc/html/latest/dev-tools/ktap.html#version-lines
+	 *
+	 * but actually isn't, as it currently depends on the KUnit module
+	 * being built-in, so we can't rely on it every time
+	 */
+	if (is_builtin) {
+		version_rptr = strcasestr(record, "TAP version ");
+		if (version_rptr == NULL)
+			return -1;
+
+		igt_info("%s", version_rptr);
+
+		if (fgets(record, BUF_LEN, fp) == NULL) {
+			igt_warn("kmsg truncated: unknown error (%m)\n");
+			return -2;
+		}
+	}
+
+	name_rptr = strcasestr(record, test_lookup_str);
+	if (name_rptr != NULL) {
+		name_rptr += strlen(test_lookup_str);
+	} else {
+		name_rptr = strcasestr(record, subtest_lookup_str);
+		if (name_rptr != NULL)
+			name_rptr += strlen(subtest_lookup_str);
+	}
+
+	if (name_rptr == NULL) {
+		if (!is_builtin)
+			/* we've probably found nothing */
+			return -1;
+		igt_info("Missing test name\n");
+	} else {
+		strncpy(test_name, name_rptr, BUF_LEN);
+		if (fgets(record, BUF_LEN, fp) == NULL) {
+			igt_warn("kmsg truncated: unknown error (%m)\n");
+			return -2;
+		}
+		/* now we can be sure we found tests */
+		if (!is_builtin)
+			igt_info("KUnit is not built-in, skipping version check...\n");
+	}
+
+	/*
+	 * total test count will almost always appear as 0..N at the beginning
+	 * of a run, so we use it to reliably identify a new run
+	 */
+	test_count = lookup_value(record, "..");
+
+	if (test_count <= 0) {
+		igt_info("Missing test count\n");
+		if (test_name[0] == '\0')
+			return 0;
+		if (log_to_end(IGT_LOG_INFO, fp, record,
+				"Running some tests in: %s",
+				test_name) < 0)
+			return -2;
+		return 0;
+	} else if (test_name[0] == '\0') {
+		igt_info("Running %ld tests...\n", test_count);
+		return 0;
+	}
+
+	if (log_to_end(IGT_LOG_INFO, fp, record,
+			"Executing %ld tests in: %s",
+			test_count, test_name) < 0)
+		return -2;
+
+	return test_count;
+}
+
+/**
+ * find_next_tap_test:
+ * @fp: FILE pointer
+ * @record: buffer used to read fp
+ * @test_name: buffer to store the test name
+ *
+ * Returns:
+ * 1 if no results were found
+ * 0 if a test succeded
+ * -1 if a test failed
+ * -2 if there are problems reading the file
+ */
+static int parse_kmsg_for_tap(FILE *fp, char *record, char *test_name)
+{
+	const char *lstart, *ok_lookup_str, *nok_lookup_str,
+	      *ok_rptr, *nok_rptr, *comment_start, *value_parse_start;
+	char *test_name_end;
+
+	ok_lookup_str = "ok ";
+	nok_lookup_str = "not ok ";
+
+	lstart = strchrnul(record, ';');
+
+	if (*lstart == '\0') {
+		igt_warn("kmsg truncated: output malformed (%m)\n");
+		return -2;
+	}
+
+	lstart++;
+	while (isspace(*lstart))
+		lstart++;
+
+	nok_rptr = strstr(lstart, nok_lookup_str);
+	if (nok_rptr != NULL) {
+		nok_rptr += strlen(nok_lookup_str);
+		while (isdigit(*nok_rptr) || isspace(*nok_rptr) || *nok_rptr == '-')
+			nok_rptr++;
+		test_name_end = strncpy(test_name, nok_rptr, BUF_LEN);
+		while (!isspace(*test_name_end))
+			test_name_end++;
+		*test_name_end = '\0';
+		if (log_to_end(IGT_LOG_WARN, fp, record,
+			       "%s", lstart) < 0)
+			return -2;
+		return -1;
+	}
+
+	comment_start = strchrnul(lstart, '#');
+
+	/* check if we're still in a subtest */
+	if (*comment_start != '\0') {
+		comment_start++;
+		value_parse_start = comment_start;
+
+		if (lookup_value(value_parse_start, "fail: ") > 0) {
+			if (log_to_end(IGT_LOG_WARN, fp, record,
+				       "%s", lstart) < 0)
+				return -2;
+			return -1;
+		}
+	}
+
+	ok_rptr = strstr(lstart, ok_lookup_str);
+	if (ok_rptr != NULL) {
+		ok_rptr += strlen(ok_lookup_str);
+		while (isdigit(*ok_rptr) || isspace(*ok_rptr) || *ok_rptr == '-')
+			ok_rptr++;
+		test_name_end = strncpy(test_name, ok_rptr, BUF_LEN);
+		while (!isspace(*test_name_end))
+			test_name_end++;
+		*test_name_end = '\0';
+		return 0;
+	}
+
+	return 1;
+}
+
+/**
+ * igt_ktap_parser:
+ * @fp: FILE pointer
+ * @record: buffer used to read fp
+ * @is_builtin: whether the KUnit module is built-in or not
+ *
+ * This function parses the output of a ktap script and prints the test results,
+ * as well as any other output to stdout.
+ *
+ * Returns: IGT default codes
+ */
+int igt_ktap_parser(FILE *fp, char *record, bool is_builtin)
+{
+	char test_name[BUF_LEN + 1];
+	bool failed_tests, found_tests;
+	int sublevel = 0;
+
+	test_name[0] = '\0';
+	test_name[BUF_LEN] = '\0';
+
+	failed_tests = false;
+	found_tests = false;
+
+	while (sublevel >= 0) {
+		if (fgets(record, BUF_LEN, fp) == NULL) {
+			if (!found_tests)
+				igt_warn("kmsg truncated: unknown error (%m)\n");
+			break;
+		}
+
+		switch (find_next_tap_subtest(fp, record, is_builtin)) {
+		case -2:
+			/* no more data to read */
+			return IGT_EXIT_FAILURE;
+		case -1:
+			/* no test found, so we keep parsing */
+			break;
+		case 0:
+			/*
+			 * tests found, but they're missing info, so we might
+			 * have read into test output
+			 */
+			found_tests = true;
+			sublevel++;
+			break;
+		default:
+			if (fgets(record, BUF_LEN, fp) == NULL) {
+				igt_warn("kmsg truncated: unknown error (%m)\n");
+				return -2;
+			}
+			found_tests = true;
+			sublevel++;
+			break;
+		}
+
+		switch (parse_kmsg_for_tap(fp, record, test_name)) {
+		case -2:
+			return IGT_EXIT_FAILURE;
+		case -1:
+			sublevel--;
+			failed_tests = true;
+			igt_subtest(test_name)
+				igt_fail(IGT_EXIT_FAILURE);
+			test_name[0] = '\0';
+			break;
+		case 0: /* fallthrough */
+			igt_subtest(test_name)
+				igt_success();
+			test_name[0] = '\0';
+		default:
+			break;
+		}
+	}
+
+	if (failed_tests || !found_tests)
+		return IGT_EXIT_FAILURE;
+
+	return IGT_EXIT_SUCCESS;
+}