What are these seemingly-useless callq instructions in my x86 object files for?

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The 00 00 00 00 (relative) target address in e8 00 00 00 00 is intended to be filled in by the linker. It doesn’t mean that the call falls through. It just means you are disassembling an object file that has not been linked yet.

Also, a call to the next instruction, if that was the end result after the link phase, would not be a no-op, because it changes the stack (a certain hint that this is not what is going on in your case).

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