Order of operations should follow order of warnings in eval

I'm trying to think of what the output of this program should be:

eval(1 = 2 = 3 / 0)

Since it should be equal to

eval((1 = 2) = (3 / 0))

I'd assume it should warn as follows:

m4:stdin:1: Warning: recommend ==, not =, for equality operator
m4:stdin:1: divide by zero in eval: 1 = 2 = 3 / 0
m4:stdin:1: Warning: recommend ==, not =, for equality operator

which would be the breadth-first left-to-right evaluation strategy,
but instead it warns like so:

m4:stdin:1: Warning: recommend ==, not =, for equality operator
m4:stdin:1: Warning: recommend ==, not =, for equality operator
m4:stdin:1: divide by zero in eval: 1 = 2 = 3 / 0

which is the depth-first left-to-right evaluation. Although, I'm not
entirely sure.

Regards,
Nikolaos Chatzikonstantinou