tests/include/test/macros.h

/**
 * \file macros.h
 *
 * \brief   This file contains generic macros for the purpose of testing.
 */

/*
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

#ifndef TEST_MACROS_H
#define TEST_MACROS_H

#include "mbedtls/build_info.h"

#include <stdlib.h>

#include "mbedtls/platform.h"

#if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
#include "mbedtls/memory_buffer_alloc.h"
#endif

/**
 * \brief   This macro tests the expression passed to it as a test step or
 *          individual test in a test case.
 *
 *          It allows a library function to return a value and return an error
 *          code that can be tested.
 *
 *          Failing the test means:
 *          - Mark this test case as failed.
 *          - Print a message identifying the failure.
 *          - Jump to the \c exit label.
 *
 *          This macro expands to an instruction, not an expression.
 *          It may jump to the \c exit label.
 *
 * \param   TEST    The test expression to be tested.
 */
#define TEST_ASSERT(TEST)                                 \
    do {                                                    \
        if (!(TEST))                                       \
        {                                                    \
            mbedtls_test_fail( #TEST, __LINE__, __FILE__);   \
            goto exit;                                        \
        }                                                    \
    } while (0)

/** Evaluate two integer expressions and fail the test case if they have
 * different values.
 *
 * The two expressions should have the same signedness, otherwise the
 * comparison is not meaningful if the signed value is negative.
 *
 * \param expr1     An integral-typed expression to evaluate.
 * \param expr2     Another integral-typed expression to evaluate.
 */
#define TEST_EQUAL(expr1, expr2)                                      \
    do {                                                                \
        if (!mbedtls_test_equal( #expr1 " == " #expr2, __LINE__, __FILE__, \
                                 expr1, expr2))                      \
        goto exit;                                                  \
    } while (0)

/** Evaluate two unsigned integer expressions and fail the test case
 * if they are not in increasing order (left <= right).
 *
 * \param expr1     An integral-typed expression to evaluate.
 * \param expr2     Another integral-typed expression to evaluate.
 */
#define TEST_LE_U(expr1, expr2)                                       \
    do {                                                                \
        if (!mbedtls_test_le_u( #expr1 " <= " #expr2, __LINE__, __FILE__, \
                                expr1, expr2))                      \
        goto exit;                                                  \
    } while (0)

/** Evaluate two signed integer expressions and fail the test case
 * if they are not in increasing order (left <= right).
 *
 * \param expr1     An integral-typed expression to evaluate.
 * \param expr2     Another integral-typed expression to evaluate.
 */
#define TEST_LE_S(expr1, expr2)                                       \
    do {                                                                \
        if (!mbedtls_test_le_s( #expr1 " <= " #expr2, __LINE__, __FILE__, \
                                expr1, expr2))                      \
        goto exit;                                                  \
    } while (0)

/** Allocate memory dynamically and fail the test case if this fails.
 * The allocated memory will be filled with zeros.
 *
 * You must set \p pointer to \c NULL before calling this macro and
 * put `mbedtls_free( pointer )` in the test's cleanup code.
 *
 * If \p length is zero, the resulting \p pointer will be \c NULL.
 * This is usually what we want in tests since API functions are
 * supposed to accept null pointers when a buffer size is zero.
 *
 * This macro expands to an instruction, not an expression.
 * It may jump to the \c exit label.
 *
 * \param pointer   An lvalue where the address of the allocated buffer
 *                  will be stored.
 *                  This expression may be evaluated multiple times.
 * \param length    Number of elements to allocate.
 *                  This expression may be evaluated multiple times.
 *
 */
#define ASSERT_ALLOC(pointer, length)                           \
    do                                                            \
    {                                                             \
        TEST_ASSERT((pointer) == NULL);                       \
        if ((length) != 0)                                     \
        {                                                         \
            (pointer) = mbedtls_calloc(sizeof(*(pointer)), \
                                       (length));           \
            TEST_ASSERT((pointer) != NULL);                   \
        }                                                         \
    }                                                             \
    while (0)

/** Allocate memory dynamically. If the allocation fails, skip the test case.
 *
 * This macro behaves like #ASSERT_ALLOC, except that if the allocation
 * fails, it marks the test as skipped rather than failed.
 */
#define ASSERT_ALLOC_WEAK(pointer, length)                      \
    do                                                            \
    {                                                             \
        TEST_ASSERT((pointer) == NULL);                       \
        if ((length) != 0)                                     \
        {                                                         \
            (pointer) = mbedtls_calloc(sizeof(*(pointer)), \
                                       (length));           \
            TEST_ASSUME((pointer) != NULL);                   \
        }                                                         \
    }                                                             \
    while (0)

/** Compare two buffers and fail the test case if they differ.
 *
 * This macro expands to an instruction, not an expression.
 * It may jump to the \c exit label.
 *
 * \param p1        Pointer to the start of the first buffer.
 * \param size1     Size of the first buffer in bytes.
 *                  This expression may be evaluated multiple times.
 * \param p2        Pointer to the start of the second buffer.
 * \param size2     Size of the second buffer in bytes.
 *                  This expression may be evaluated multiple times.
 */
#define ASSERT_COMPARE(p1, size1, p2, size2)                          \
    do                                                                  \
    {                                                                   \
        TEST_EQUAL((size1), (size2));                          \
        if ((size1) != 0)                                            \
        TEST_ASSERT(memcmp((p1), (p2), (size1)) == 0);    \
    }                                                                   \
    while (0)

/**
 * \brief   This macro tests the expression passed to it and skips the
 *          running test if it doesn't evaluate to 'true'.
 *
 * \param   TEST    The test expression to be tested.
 */
#define TEST_ASSUME(TEST)                                 \
    do {                                                    \
        if (!(TEST))                                      \
        {                                                   \
            mbedtls_test_skip( #TEST, __LINE__, __FILE__); \
            goto exit;                                      \
        }                                                   \
    } while (0)

#define TEST_HELPER_ASSERT(a) if (!(a))                          \
    {                                                                   \
        mbedtls_fprintf(stderr, "Assertion Failed at %s:%d - %s\n",    \
                        __FILE__, __LINE__, #a);              \
        mbedtls_exit(1);                                              \
    }

/** \def ARRAY_LENGTH
 * Return the number of elements of a static or stack array.
 *
 * \param array         A value of array (not pointer) type.
 *
 * \return The number of elements of the array.
 */
/* A correct implementation of ARRAY_LENGTH, but which silently gives
 * a nonsensical result if called with a pointer rather than an array. */
#define ARRAY_LENGTH_UNSAFE(array)            \
    (sizeof(array) / sizeof(*(array)))

#if defined(__GNUC__)
/* Test if arg and &(arg)[0] have the same type. This is true if arg is
 * an array but not if it's a pointer. */
#define IS_ARRAY_NOT_POINTER(arg)                                     \
    (!__builtin_types_compatible_p(__typeof__(arg),                \
                                   __typeof__(&(arg)[0])))
/* A compile-time constant with the value 0. If `const_expr` is not a
 * compile-time constant with a nonzero value, cause a compile-time error. */
#define STATIC_ASSERT_EXPR(const_expr)                                \
    (0 && sizeof(struct { unsigned int STATIC_ASSERT : 1 - 2 * !(const_expr); }))

/* Return the scalar value `value` (possibly promoted). This is a compile-time
 * constant if `value` is. `condition` must be a compile-time constant.
 * If `condition` is false, arrange to cause a compile-time error. */
#define STATIC_ASSERT_THEN_RETURN(condition, value)   \
    (STATIC_ASSERT_EXPR(condition) ? 0 : (value))

#define ARRAY_LENGTH(array)                                           \
    (STATIC_ASSERT_THEN_RETURN(IS_ARRAY_NOT_POINTER(array),         \
                               ARRAY_LENGTH_UNSAFE(array)))

#else
/* If we aren't sure the compiler supports our non-standard tricks,
 * fall back to the unsafe implementation. */
#define ARRAY_LENGTH(array) ARRAY_LENGTH_UNSAFE(array)
#endif

/** Return the smaller of two values.
 *
 * \param x         An integer-valued expression without side effects.
 * \param y         An integer-valued expression without side effects.
 *
 * \return The smaller of \p x and \p y.
 */
#define MIN(x, y) ((x) < (y) ? (x) : (y))

/** Return the larger of two values.
 *
 * \param x         An integer-valued expression without side effects.
 * \param y         An integer-valued expression without side effects.
 *
 * \return The larger of \p x and \p y.
 */
#define MAX(x, y) ((x) > (y) ? (x) : (y))

#endif /* TEST_MACROS_H */