Trying to visualize an abstract syntax tree in graphviz dot, and it's just way too wide. How to fix?

Question

So I'm working on a language and I wanted to, mostly out of curiosity, see if I could visualize the abstract syntax tree of a file. After some looking around I found graphviz dot, converted my AST prettyprinter to be able to output to this kind of format:

digraph G {
    main -> parse -> execute;
    main -> init;
    main -> cleanup;
    execute -> make_string;
    execute -> printf
    init -> make_string;
    main -> printf;
    execute -> compare;
}

But my problem is, when I run

dot -Tpng dotf.gv -o graph.png

On the input file, I end up with a file that is 8000 pixels in width, which is just not practical. See here.

I don't know if it's possible to fix, but if someone can I'd be grateful.

Answer 1

The first thing to do would be to set the direction of the graph from the default bottom-to-top ranking to left-to-right, by inserting:

rankdir=LR;

... in the .dot file. That should orient the graph left-to-right and thereby make it much more compact for a case like this that probably has many nodes with long node labels.

There are some other ideas for reducing the width of graphs like this in Create a call graph for a file with clang.