libakstdlib/tests/aksl_capture.h

#ifndef AKSL_TEST_CAPTURE_H
#define AKSL_TEST_CAPTURE_H

/*
 * Shared test helpers for libakstdlib.
 *
 * Modelled on libakerror's tests/err_capture.h, with additions for the shape of
 * this library: almost every akstdlib entry point returns an
 * akerr_ErrorContext * that the caller owns and must release, so the common
 * assertion is "this call returned status X" rather than "this call logged Y".
 *
 * What is here:
 *
 *   AKSL_CHECK()            an NDEBUG-proof assertion. Fails the test by
 *                           returning 1 from the enclosing function (unlike
 *                           assert(), which is compiled out in release builds
 *                           and would silently turn a test into a no-op).
 *   AKSL_CHECK_STATUS()     run an akerror-returning expression, assert on the
 *                           status it came back with, and release the context
 *                           so the error pool does not leak.
 *   AKSL_CHECK_OK()         the status == 0 (success) case of the above.
 *   aksl_last_status/...    the status, message and function name of the most
 *                           recent context taken by AKSL_CHECK_STATUS.
 *   aksl_capture_install()  swap in a capturing akerr_log_method so a test can
 *                           assert on the *content* of stack traces and
 *                           unhandled-error output.
 *   aksl_slots_in_use()     how many slots are currently checked out of
 *                           AKERR_ARRAY_ERROR, for pool-leak assertions.
 *   AKSL_RUN()              run one test function and tally the result.
 *
 * Tests are written as a set of `static int test_xxx(void)` functions that
 * return 0 on success and non-zero on failure, driven from main() by AKSL_RUN.
 */

#include <akstdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>

/* ---------------------------------------------------------------------- */
/* Log capture                                                            */
/* ---------------------------------------------------------------------- */

#define AKSL_CAPTURE_BUFSZ 65536
static char aksl_capture_buf[AKSL_CAPTURE_BUFSZ];
static size_t aksl_capture_len = 0;

static void __attribute__((unused)) aksl_capture_logger(const char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    int n = vsnprintf(aksl_capture_buf + aksl_capture_len,
		      AKSL_CAPTURE_BUFSZ - aksl_capture_len, fmt, ap);
    va_end(ap);
    if ( n > 0 ) {
	aksl_capture_len += (size_t)n;
	if ( aksl_capture_len >= AKSL_CAPTURE_BUFSZ ) {
	    aksl_capture_len = AKSL_CAPTURE_BUFSZ - 1;
	}
    }
}

static void __attribute__((unused)) aksl_capture_reset(void)
{
    aksl_capture_len = 0;
    aksl_capture_buf[0] = '\0';
}

/*
 * Install the capturing logger. akerr_init() only assigns a default logger when
 * akerr_log_method is NULL, and it is idempotent, so calling this either before
 * or after the first PREPARE_ERROR keeps our logger in place.
 */
static void __attribute__((unused)) aksl_capture_install(void)
{
    aksl_capture_reset();
    akerr_log_method = &aksl_capture_logger;
}

/* ---------------------------------------------------------------------- */
/* Error pool accounting                                                  */
/* ---------------------------------------------------------------------- */

/* Count array slots currently checked out of the pool (refcount != 0). */
static int __attribute__((unused)) aksl_slots_in_use(void)
{
    int n = 0;
    for ( int i = 0; i < AKERR_MAX_ARRAY_ERROR; i++ ) {
	if ( AKERR_ARRAY_ERROR[i].refcount != 0 ) {
	    n++;
	}
    }
    return n;
}

/* ---------------------------------------------------------------------- */
/* Taking ownership of a returned error context                           */
/* ---------------------------------------------------------------------- */

static int aksl_last_status = 0;
static char aksl_last_message[AKERR_MAX_ERROR_CONTEXT_STRING_LENGTH];
/* Sized to match akerr_ErrorContext.function, which akerror declares with
 * AKERR_MAX_ERROR_FNAME_LENGTH rather than AKERR_MAX_ERROR_FUNCTION_LENGTH. */
static char aksl_last_function[AKERR_MAX_ERROR_FNAME_LENGTH];

/*
 * Record the status/message/function of a returned context, release it back to
 * the pool, and hand back the status. A NULL context means success, which is
 * status 0. Every akstdlib call in a test should go through this (or through
 * AKSL_CHECK_STATUS, which wraps it) so that no test leaks a pool slot.
 */
static int __attribute__((unused)) aksl_take(akerr_ErrorContext *e)
{
    akerr_ErrorContext *released = NULL;

    aksl_last_message[0] = '\0';
    aksl_last_function[0] = '\0';
    if ( e == NULL ) {
	aksl_last_status = 0;
	return 0;
    }
    aksl_last_status = e->status;
    snprintf(aksl_last_message, sizeof(aksl_last_message), "%s", e->message);
    snprintf(aksl_last_function, sizeof(aksl_last_function), "%s", e->function);
    /*
     * akerr_release_error is marked warn_unused_result, and a (void) cast does
     * not silence that in GCC, so the result is assigned and discarded.
     */
    released = akerr_release_error(e);
    (void)released;
    return aksl_last_status;
}

/* ---------------------------------------------------------------------- */
/* Assertions                                                             */
/* ---------------------------------------------------------------------- */

#define AKSL_CHECK(cond)					\
    do {							\
	if ( !(cond) ) {					\
	    fprintf(stderr, "  CHECK FAILED: %s at %s:%d\n",	\
		    #cond, __FILE__, __LINE__);			\
	    return 1;						\
	}							\
    } while ( 0 )

/*
 * Run an akerr_ErrorContext *-returning expression and assert on its status.
 * The context is always released, including on the failure path, so a failing
 * assertion does not also corrupt the pool-leak checks that follow it.
 */
#define AKSL_CHECK_STATUS(__expr, __expected)				\
    do {								\
	int __st = aksl_take(__expr);					\
	if ( __st != (__expected) ) {					\
	    fprintf(stderr,						\
		    "  CHECK FAILED: %s\n"				\
		    "    got      %d (%s) \"%s\"\n"			\
		    "    expected %d (%s)\n"				\
		    "    at %s:%d\n",					\
		    #__expr,						\
		    __st, akerr_name_for_status(__st, NULL),		\
		    aksl_last_message,					\
		    (__expected),					\
		    akerr_name_for_status((__expected), NULL),		\
		    __FILE__, __LINE__);				\
	    return 1;							\
	}								\
    } while ( 0 )

#define AKSL_CHECK_OK(__expr) AKSL_CHECK_STATUS(__expr, 0)

#define AKSL_CHECK_CONTAINS(needle)				\
    AKSL_CHECK(strstr(aksl_capture_buf, (needle)) != NULL)

#define AKSL_CHECK_NOT_CONTAINS(needle)				\
    AKSL_CHECK(strstr(aksl_capture_buf, (needle)) == NULL)

/* Assert on the message of the context most recently taken. */
#define AKSL_CHECK_MSG_CONTAINS(needle)				\
    AKSL_CHECK(strstr(aksl_last_message, (needle)) != NULL)

/* ---------------------------------------------------------------------- */
/* Test driver                                                            */
/* ---------------------------------------------------------------------- */

/*
 * Run one test function, report it, and tally failures. Also asserts that the
 * test left the error pool as it found it -- a wrapper that fails to release a
 * context is a bug in the library, not just in the test.
 */
#define AKSL_RUN(__failures, __fn)					\
    do {								\
	int __before = aksl_slots_in_use();				\
	int __r = __fn();						\
	int __after = aksl_slots_in_use();				\
	if ( __r != 0 ) {						\
	    fprintf(stderr, "FAIL %s\n", #__fn);			\
	    (__failures)++;						\
	} else if ( __after != __before ) {				\
	    fprintf(stderr,						\
		    "FAIL %s (leaked %d error pool slot(s))\n",		\
		    #__fn, __after - __before);				\
	    (__failures)++;						\
	} else {							\
	    fprintf(stderr, "ok   %s\n", #__fn);			\
	}								\
    } while ( 0 )

#define AKSL_REPORT(__failures)						\
    do {								\
	fprintf(stderr, "%s: %d failure(s)\n", __FILE__, (__failures));	\
	return (__failures) == 0 ? 0 : 1;				\
    } while ( 0 )

#endif // AKSL_TEST_CAPTURE_H