分段错误或可疑的指针到指针转换（面积太小）

Question

long keyIntValue;
uint8_t *value; 

sscanf(buffer, " %*[^\"\n]\"%9[^;\"\n]", keyStringValue);
keyIntValue = strtol(keyStringValue, NULL, 16);
*value = *(uint8_t*)keyIntValue;
printf("The value is 0x%x \n", *value);

I get segmentation fault for the above code with GCC compiler

*(long *)value = keyIntValue;
 printf("The value is 0x%x \n", *(long *)value);

The above code works with gcc and gets the correct output but I get Suspicious pointer-to-pointer conversion (area too small) with bitbake compiler

How to solve this?

Answer 1

*value = *(uint8_t*)keyIntValue;

取消引用未初始化的指针会导致未定义的行为，从而导致分段错误。

Answer 2

If you would like to treat a portion of keyIntValue as a uint8_t , you can do it by taking an address of keyIntValue , like this:

unsigned char *value;
value = (unsigned char*)(&keyIntValue);
printf("The value is 0x%x \n", *value);

Note: The reason I changed the type of value to a pointer to unsigned char is to avoid violating the strict aliasing rule. Pointers to character types are allowed to alias to anything, so changing the type fixes the aliasing problem.