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//! Generating Graphviz `dot` files from our IR.
use super::context::{BindgenContext, ItemId};
use super::traversal::Trace;
use std::fs::File;
use std::io::{self, Write};
use std::path::Path;
/// A trait for anything that can write attributes as `<table>` rows to a dot
/// file.
pub(crate) trait DotAttributes {
/// Write this thing's attributes to the given output. Each attribute must
/// be its own `<tr>...</tr>`.
fn dot_attributes<W>(
&self,
ctx: &BindgenContext,
out: &mut W,
) -> io::Result<()>
where
W: io::Write;
}
/// Write a graphviz dot file containing our IR.
pub(crate) fn write_dot_file<P>(ctx: &BindgenContext, path: P) -> io::Result<()>
where
P: AsRef<Path>,
{
let file = File::create(path)?;
let mut dot_file = io::BufWriter::new(file);
writeln!(&mut dot_file, "digraph {{")?;
let mut err: Option<io::Result<_>> = None;
for (id, item) in ctx.items() {
let is_allowlisted = ctx.allowlisted_items().contains(&id);
writeln!(
&mut dot_file,
r#"{} [fontname="courier", color={}, label=< <table border="0" align="left">"#,
id.as_usize(),
if is_allowlisted { "black" } else { "gray" }
)?;
item.dot_attributes(ctx, &mut dot_file)?;
writeln!(&mut dot_file, r#"</table> >];"#)?;
item.trace(
ctx,
&mut |sub_id: ItemId, edge_kind| {
if err.is_some() {
return;
}
match writeln!(
&mut dot_file,
"{} -> {} [label={:?}, color={}];",
id.as_usize(),
sub_id.as_usize(),
edge_kind,
if is_allowlisted { "black" } else { "gray" }
) {
Ok(_) => {}
Err(e) => err = Some(Err(e)),
}
},
&(),
);
if let Some(err) = err {
return err;
}
if let Some(module) = item.as_module() {
for child in module.children() {
writeln!(
&mut dot_file,
"{} -> {} [style=dotted, color=gray]",
item.id().as_usize(),
child.as_usize()
)?;
}
}
}
writeln!(&mut dot_file, "}}")?;
Ok(())
}