How to enter a file using gallium?

[chobb...@gmail.com]

Hi there,

I'm totally new to the new debuggers. What I'm aiming at is to go through a file (it's a file calling other packages and functions therein.) line by line, just like in matlab. The first step is to step in the file using gallium. I know how to traverse a function in terminal using Gallium. But it seems that I can't enter a file by doing the same thing like:

julia> @enter test.jl
ERROR: BoundsError: attempt to access 0-element Array{Int64,1} at index [0]

How can I enter a file via Gallium? Is it possible at all? Thanks.

[Michele Zaffalon]

You @enter the function, not the file. What function would you call once you include test.jl? That is the function to which you should prepend @enter.

[chobb...@gmail.com]

Thanks for the comments. I tried what you suggested by adding @enter at the beginning of a line where a function is called. But an error was thrown.

julia> include("/home/calvin/Documents/git/codes/fc.jl/examples/test.jl")
ERROR: LoadError: AssertionError: isa(arg,Expr) && arg.head == :call
 in include_from_node1(::String) at ./loading.jl:488
while loading /home/calvin/Documents/git/codes/fc.jl/examples/test.jl, in expression starting on line 19

Am I missing anything? Thanks!

[Michele Zaffalon]

The @enter should be prepended to the function in the REPL, not in the
file itself. It should be something like this:

julia> include("/home/calvin/Documents/git/codes/fc.jl/examples/test.jl")

julia> @enter function_to_debug(args_to_function)

[chobb...@gmail.com]

Thanks! It now works for me. Two more quick questions:

1. Suppose I have the following code where the variable A is defined multiple times and after each definition it is used by the same function function_to_debug. How can I step in function_to_debug with the first definition/instantiation of A?

A = ...
function_to_debug(A)
...
...
A = ...
function_to_debug(A)

2. As I'm step through the function_to_debug(), how can I print the value of some variables. I know that I can use 'fr v' which prints everything. How can I print just a single variable that I'm looking at?

Thanks!!

[Michele Zaffalon]

I don't know the answer to the first question.

For the second, you should check
https://github.com/Keno/ASTInterpreter.jl and in particular the
command `stuff.

[chobb...@gmail.com]

Thanks for the comments on my second question. I missed the acute prepended before 'stuff'.

[chobb...@gmail.com]

Bump up for the following question:

Suppose I have the following code where the variable A is defined multiple times and after each definition it is used by the same function function_to_debug. How can I step in function_to_debug with the first definition/instantiation of A?

A = ...
function_to_debug(A)
...
...
A = ...
function_to_debug(A)

Seems that the only choice is to use breakpoint. Any other means without resorting to breakpoints??

[Isaiah Norton]

Any other means without resorting to breakpoints??

Use `@enter function_to_debug( ... )` with the value of A that you are interested in. 

[chobb...@gmail.com]

Well, if A is a complicated object/structure, it'll be almost impossible to first make up an A and call @enter function_to_debug(A).

[Isaiah Norton]

If breakpoints aren't working, I would suggest to your push object(s) of interest into a global Vector{Any} and then debug with `@enter`.

[Michele Zaffalon]

How would you do that in MATLAB?

[chobb...@gmail.com]

That's a good stopgap, if there's better options. Thanks!!