rust/compiler/rustc_passes/src/debugger_visualizer.rs
2022-05-04 17:17:57 -07:00

138 lines
4.8 KiB
Rust

//! Detecting usage of the `#[debugger_visualizer]` attribute.
use hir::CRATE_HIR_ID;
use rustc_data_structures::fx::FxHashSet;
use rustc_expand::base::resolve_path;
use rustc_hir as hir;
use rustc_hir::def_id::CrateNum;
use rustc_hir::itemlikevisit::ItemLikeVisitor;
use rustc_hir::{HirId, Target};
use rustc_middle::ty::query::Providers;
use rustc_middle::ty::TyCtxt;
use rustc_span::def_id::LOCAL_CRATE;
use rustc_span::{sym, DebuggerVisualizerFile, DebuggerVisualizerType};
use std::sync::Arc;
struct DebuggerVisualizerCollector<'tcx> {
debugger_visualizers: FxHashSet<DebuggerVisualizerFile>,
tcx: TyCtxt<'tcx>,
}
impl<'v, 'tcx> ItemLikeVisitor<'v> for DebuggerVisualizerCollector<'tcx> {
fn visit_item(&mut self, item: &hir::Item<'_>) {
let target = Target::from_item(item);
match target {
Target::Mod => {
self.check_for_debugger_visualizer(item.hir_id());
}
_ => {}
}
}
fn visit_trait_item(&mut self, _: &hir::TraitItem<'_>) {}
fn visit_impl_item(&mut self, _: &hir::ImplItem<'_>) {}
fn visit_foreign_item(&mut self, _: &hir::ForeignItem<'_>) {}
}
impl<'tcx> DebuggerVisualizerCollector<'tcx> {
fn new(tcx: TyCtxt<'tcx>) -> DebuggerVisualizerCollector<'tcx> {
DebuggerVisualizerCollector { tcx, debugger_visualizers: FxHashSet::default() }
}
fn check_for_debugger_visualizer(&mut self, hir_id: HirId) {
let attrs = self.tcx.hir().attrs(hir_id);
for attr in attrs {
if attr.has_name(sym::debugger_visualizer) {
let list = match attr.meta_item_list() {
Some(list) => list,
_ => continue,
};
let meta_item = match list.len() {
1 => match list[0].meta_item() {
Some(meta_item) => meta_item,
_ => continue,
},
_ => continue,
};
let file = match (meta_item.name_or_empty(), meta_item.value_str()) {
(sym::natvis_file, Some(value)) => {
match resolve_path(&self.tcx.sess.parse_sess, value.as_str(), attr.span) {
Ok(file) => file,
Err(mut err) => {
err.emit();
continue;
}
}
}
(_, _) => continue,
};
if file.is_file() {
let contents = match std::fs::read(&file) {
Ok(contents) => contents,
Err(err) => {
self.tcx
.sess
.struct_span_err(
attr.span,
&format!(
"Unable to read contents of file `{}`. {}",
file.display(),
err
),
)
.emit();
continue;
}
};
self.debugger_visualizers.insert(DebuggerVisualizerFile::new(
Arc::from(contents),
DebuggerVisualizerType::Natvis,
));
} else {
self.tcx
.sess
.struct_span_err(
attr.span,
&format!("{} is not a valid file", file.display()),
)
.emit();
}
}
}
}
}
/// Traverses and collects the debugger visualizers for a specific crate.
fn debugger_visualizers<'tcx>(tcx: TyCtxt<'tcx>, cnum: CrateNum) -> Vec<DebuggerVisualizerFile> {
assert_eq!(cnum, LOCAL_CRATE);
// Initialize the collector.
let mut collector = DebuggerVisualizerCollector::new(tcx);
// Collect debugger visualizers in this crate.
tcx.hir().visit_all_item_likes(&mut collector);
// Collect debugger visualizers on the crate attributes.
collector.check_for_debugger_visualizer(CRATE_HIR_ID);
// Extract out the found debugger_visualizer items.
let DebuggerVisualizerCollector { debugger_visualizers, .. } = collector;
let mut visualizers = debugger_visualizers.into_iter().collect::<Vec<_>>();
// Sort the visualizers so we always get a deterministic query result.
visualizers.sort();
visualizers
}
pub fn provide(providers: &mut Providers) {
providers.debugger_visualizers = debugger_visualizers;
}