Stepping and macros

[timholy]

On Julia 1.12 (with the new linetable implementation), a stepping test fails at

JuliaInterpreter.jl/test/debug.jl

Line 254 in 6031ed7

f, pc = debug_command(f, :n) # x is set

because it ends up "prematurely" at the final return statement. Specifically, rather than just setting x, it executes the entire macro

JuliaInterpreter.jl/test/debug.jl

Lines 41 to 47 in 6031ed7

	macro insert_some_calls()
	esc(quote
	x = sin(b)
	y = asin(x)
	z = sin(y)
	end)
	end

In other words, in Julia 1.12, "step-next" steps "over" the macro. There are some things I like about this behavior (it matches what the developer sees when looking at the code that calls the macro).

You might imagine that "step-in" would step into the macro, but that's not currently true: it steps into the implementation of sin. So it's definitely inconsistent. We could either make it behave the same as previous versions, or decide we like the idea of stepping into the macro and figure out how to get that working properly (it would be a breaking change).