【C/C++】函数入参检查

// 统计变参数量
#define CALC_VA_COUNT(arg...) \
    ({ \
        int count = 0; \
        int insideQuotes = 0; \
        const char *str = #arg; \
        printf("D> CALC_VA_COUNT: %s\n", str); \
        while (*str != '\0') { \
            if (*str == '"') { \
                insideQuotes = !insideQuotes; \
            } else if (*str == ',' && !insideQuotes) { \
                count++; \
            } \
            str++; \
        } \
        ++count; \
    })

// 变参数量多于1个，则生效最后1个（逗号表达式）
#define CHECK(expr, ...) \
    do { \
        if (!(expr)) { \
            printf("check fail: \"%s\" @ %s, %u\r\n", #expr, __FILE__, __LINE__); \
            return __VA_ARGS__; \
        } \
    } while(0)

#define ASSERT(expr)    (void)((!!(expr)) || (printf("assert fail: \"%s\" @ %s, %u", #expr, __FILE__, __LINE__), printf("\r\n")))
// usage:
ASSERT(arg != NULL)
 
#define ASSERT(expr)    (void)((!!(expr)) && (printf("assert fail: \"%s\" @ %s, %u", #expr, __FILE__, __LINE__), printf("\r\n")))
// usage:
ASSERT(arg == NULL)
 
#define ASSERT(expr)    (int)((!!(expr)) || (printf("assert fail: \"%s\" @ %s, %u", #expr, __FILE__, __LINE__), printf("\r\n"), Abort()))
// usage:
if (!ASSERT(arg != NULL)) {
    return;
}
 
#define ASSERT(expr)    (int)((!!(expr)) && (printf("assert fail: \"%s\" @ %s, %u", #expr, __FILE__, __LINE__), printf("\r\n"), Abort()))
// usage:
if (!ASSERT(arg == NULL)) {
    return;
}

int Abort(void)
{
    printf("reset reboot!\n");
    // 处理异常代码
}

示例：

// Powered by skull
#include <stdio.h>
 
#define CALC_VA_COUNT(arg...) \
    ({ \
        int count = 0; \
        int insideQuotes = 0; \
        const char *str = #arg; \
        printf("D> CALC_VA_COUNT: %s\n", str); \
        while (*str != '\0') { \
            if (*str == '"') { \
                insideQuotes = !insideQuotes; \
            } else if (*str == ',' && !insideQuotes) { \
                count++; \
            } \
            str++; \
        } \
        ++count; \
    })
 
#define CHECK(expr, ...) \
    do { \
        if (!(expr)) { \
            printf("I> check fail: \"%s\" @ %s, %u\r\n", #expr, __FILE__, __LINE__); \
            printf("D> __VA_ARGS__: %s\r\n", #__VA_ARGS__); \
            if (CALC_VA_COUNT(__VA_ARGS__) > 1) printf("W> too many parameters. last effective!\r\n"); \
            return __VA_ARGS__; \
        } \
    } while(0)
 
#define ASSERT1(expr)    (void)((!!(expr)) || (printf("A> assert fail: \"%s\" @ %s, %u", #expr, __FILE__, __LINE__), printf("\r\n")))
#define ASSERT2(expr)    (void)((!!(expr)) && (printf("A> assert fail: \"%s\" @ %s, %u", #expr, __FILE__, __LINE__), printf("\r\n")))
#define ASSERT3(expr)    (int)((!!(expr)) || (printf("A> assert fail: \"%s\" @ %s, %u", #expr, __FILE__, __LINE__), printf("\r\n"), Abort1()))
#define ASSERT4(expr)    (int)((!!(expr)) && (printf("A> assert fail: \"%s\" @ %s, %u", #expr, __FILE__, __LINE__), printf("\r\n"), Abort2()))
 
int Abort1(void)
{
    printf("reset reboot!\n");
    // 异常处理
}
 
int Abort2(void)
{
    printf("reset reboot!\n");
    // 异常处理
    return -1;
}
 
void test_assert(void *pointer)
{
    ASSERT1(pointer != NULL);
    ASSERT2(pointer == NULL);
    if (ASSERT3(pointer != NULL)) {
        printf("ASSERT3\n");
    }
    if (!ASSERT3(pointer != NULL)) {
        printf("!ASSERT3\n");
    }
    if (ASSERT4(pointer == NULL)) {
        printf("ASSERT4\n");
    }
    if (!ASSERT4(pointer == NULL)) {
        printf("!ASSERT4\n");
    }
}
 
void test_check(void *pointer)
{
    CHECK(pointer == NULL);
    printf("check @%s\n", __func__);
}
 
void test_check1(void *pointer)
{
    CHECK(pointer != NULL);
    printf("check @%s\n", __func__);
}
 
char *test_check2(void *pointer)
{
    CHECK(pointer != NULL, "check fail!");
    printf("check @%s\n", __func__);
}
 
char *test_check3(void *pointer)
{
    CHECK(pointer != NULL, "check fail!", __func__);
    printf("check @%s\n", __func__);
}
 
int main(void)
{
    int *arg;
    printf("Hello Assert!\n");
    test_assert(arg);
    printf("Hello check!\n");
    test_check(arg);
    test_check1(arg);
    printf("check result: %s\n", test_check2(arg));
    printf("check result: %s\n", test_check3(arg));
    return 0;
}