Why do I get “warning: missing initializer for member”? [-Wmissing-field-initializers]

Question

I\'m wondering why I am getting a warning about initialization in one case, but not the other. The code is in a C++ source file, and using GCC 4.7 with -std=c++11

Answer 1

The compiler warns that all members are not initialized when you initialize the struct. There is nothing to warn about declaring an uninitialized struct. You should get the same warnings when you (partially) initialize the uninitialized structs.

struct sigaction old_handler, new_handler;
old_handler = {};
new_handler = {};

So, that's the difference. Your code that doesn't produce the warning is not an initialization at all. Why gcc warns about zero initialized struct at all is beyond me.