A Problem on `va_list` in C Language
What’s the output of the following codes? And Why? #include <stdio.h> int main(int argc, char *argv[]) { printf("%#018llx\n", (char)0x80); printf("%#018llx\n", (unsigned char)0x80); return 0; } (You might encounter warnings informing you of the inconsistency between the specified format and the given arguments. Let’s neglect them.) The answer is 0x00000000ffffff80 0x0000000000000080 Questions We have two questions: Is it overloading that contributes to different behaviors when different types of arguments are passed. Why is the first output 0x00000000ffffff80 instead of 0xffffffffffffff80? Answers The analysis is based on the printf implementation in x86 linux boot ...