use annotate_snippets::{Level, Renderer, Snippet};
use once_cell::sync::OnceCell;
use rustc_hir::def_id::DefId;
use rustc_middle::ty::TyCtxt;
use rustc_span::Span;
use crate::{
analysis::{
core::dataflow::{graph::*, *},
opt::OptCheck,
utils::def_path::DefPath,
},
utils::log::{relative_pos_range, span_to_filename, span_to_line_number, span_to_source_code},
};
struct DefPaths {
vec_from_elem: DefPath,
}
static DEFPATHS: OnceCell<DefPaths> = OnceCell::new();
impl DefPaths {
pub fn new(tcx: &TyCtxt<'_>) -> Self {
Self {
vec_from_elem: DefPath::new("std::vec::from_elem", tcx),
}
}
fn has_id(&self, def_id: DefId) -> bool {
def_id == self.vec_from_elem.last_def_id()
}
}
pub struct VecInitCheck {
record: Vec<Span>,
}
impl OptCheck for VecInitCheck {
fn new() -> Self {
Self { record: Vec::new() }
}
fn check(&mut self, graph: &Graph, tcx: &TyCtxt) {
let def_paths = &DEFPATHS.get_or_init(|| DefPaths::new(tcx));
for node in graph.nodes.iter() {
for op in node.ops.iter() {
if let NodeOp::Call(def_id) = op {
if def_paths.has_id(*def_id) {
self.record.push(node.span);
}
}
}
}
}
fn report(&self, graph: &Graph) {
for span in self.record.iter() {
report_vec_init(graph, *span);
}
}
fn cnt(&self) -> usize {
self.record.len()
}
}
fn report_vec_init(graph: &Graph, span: Span) {
let code_source = span_to_source_code(graph.span);
let filename = span_to_filename(span);
let snippet = Snippet::source(&code_source)
.line_start(span_to_line_number(graph.span))
.origin(&filename)
.fold(true)
.annotation(
Level::Error
.span(relative_pos_range(graph.span, span))
.label("Initialization happens here"),
);
let message = Level::Warning
.title("Unnecessary data collection initialization detected")
.snippet(snippet)
.footer(Level::Help.title("Use unsafe APIs to skip initialization."));
let renderer = Renderer::styled();
println!("{}", renderer.render(message));
}