rapx 0.7.31

A static analysis platform for Rust program analysis and verification
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use once_cell::sync::OnceCell;

use rustc_hir::intravisit;
use rustc_middle::ty::TyCtxt;
use rustc_span::Span;

use crate::analysis::dataflow::Graph;
use crate::helpers::def_path::DefPath;
use crate::utils::span::{
    span_to_first_line, span_to_trimmed_span,
};

use annotate_snippets::Level;

use crate::check::opt::report::OptReport;

use super::super::super::LEVEL;
use super::super::super::NO_STD;
use super::super::super::loop_visitors::LoopFinder;
static DEFPATHS: OnceCell<DefPaths> = OnceCell::new();

struct DefPaths {
    vec_push: DefPath,
}

impl DefPaths {
    pub fn new(tcx: &TyCtxt<'_>) -> Self {
        let no_std = NO_STD.lock().unwrap();
        if *no_std {
            Self {
                vec_push: DefPath::new("alloc::vec::Vec::push", tcx),
            }
        } else {
            Self {
                vec_push: DefPath::new("std::vec::Vec::push", tcx),
            }
        }
    }
}

use crate::check::opt::OptCheck;

pub struct BoundsLoopPushCheck {
    pub record: Vec<(Span, Vec<Span>)>,
}

impl OptCheck for BoundsLoopPushCheck {
    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));
        let level = LEVEL.lock().unwrap();
        if *level == 2 {
            let def_id = graph.def_id;
            let body = tcx.hir_body_owned_by(def_id.as_local().unwrap());
            let typeck_results = tcx.typeck(def_id.as_local().unwrap());
            let target_def_id = def_paths.vec_push.last_def_id();
            let mut loop_finder = LoopFinder::new(typeck_results, target_def_id);
            intravisit::walk_body(&mut loop_finder, body);
            self.record = loop_finder.into_record();
        }
    }

    fn report(&self, _: &Graph) {
        for (loop_span, push_record) in self.record.iter() {
            report_loop_push_bug(*loop_span, push_record);
        }
    }

    fn cnt(&self) -> usize {
        self.record.iter().map(|(_, spans)| spans.len()).sum()
    }
}

fn report_loop_push_bug(loop_span: Span, push_record: &Vec<Span>) {
    let trimmed = span_to_trimmed_span(span_to_first_line(loop_span));
    let mut report = OptReport::new(loop_span, loop_span)
        .title("Unnecessary bounds checkings detected")
        .annotate(Level::Info, trimmed, "A loop operation.");
    for push_span in push_record {
        report = report.annotate(Level::Error, *push_span, "Push happens here.");
    }
    report.emit();
}