rapx 0.7.31

A static analysis platform for Rust program analysis and verification
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use super::value_is_from_const;
use crate::{
    analysis::dataflow::*,
};
use rustc_middle::{mir::Local, ty::TyCtxt};
use rustc_span::Span;

use annotate_snippets::Level;

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

crate::def_paths! {
    string_new: "std::string::String::new",
    string_push: "std::string::String::push",
}


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

pub struct StringPushCheck {
    record: Vec<Span>,
}

fn extract_value_if_is_string_push(graph: &Graph, node: &GraphNode) -> Option<Local> {
    let def_paths = DEFPATHS.get().unwrap();
    for op in node.ops.iter() {
        if let NodeOp::Call(def_id) = op {
            if *def_id == def_paths.string_push.last_def_id() {
                let push_value_idx = graph.edges[node.in_edges[1]].src; //the secod parameter
                return Some(push_value_idx);
            }
        }
    }
    None
}

fn find_upside_string_new(graph: &Graph, node_idx: Local) -> Option<Local> {
    let def_paths = DEFPATHS.get().unwrap();
    graph.find_first_node(
        node_idx,
        Direction::Upside,
        &mut |graph: &Graph, idx: Local| {
            let node = &graph.nodes[idx];
            for op in node.ops.iter() {
                if let NodeOp::Call(def_id) = op {
                    if *def_id == def_paths.string_new.last_def_id() {
                        return true;
                    }
                }
            }
            false
        },
        &mut Graph::always_true_edge_validator,
    )
}

impl OptCheck for StringPushCheck {
    fn new() -> Self {
        Self { record: Vec::new() }
    }

    fn check(&mut self, graph: &Graph, tcx: &TyCtxt) {
        let _ = &DEFPATHS.get_or_init(|| DefPaths::new(tcx));
        for (node_idx, node) in graph.nodes.iter_enumerated() {
            if let Some(pushed_value_idx) = extract_value_if_is_string_push(graph, node) {
                if find_upside_string_new(graph, node_idx).is_some() {
                    if !value_is_from_const(graph, pushed_value_idx) {
                        self.record.clear(); // Warning: Not rigorous, push of other string may cause clear
                        return;
                    }
                    self.record.push(node.span);
                }
            }
        }
    }

    fn report(&self, graph: &Graph) {
        if !self.record.is_empty() {
            report_string_push_bug(graph, &self.record);
        }
    }

    fn cnt(&self) -> usize {
        self.record.len()
    }
}

fn report_string_push_bug(graph: &Graph, spans: &Vec<Span>) {
    let mut report = OptReport::from_graph(graph)
        .title("Unnecessary encoding checkings detected");
    for span in spans.iter() {
        report = report.annotate(Level::Error, *span, "Checked here.");
    }
    report.footer("Use unsafe APIs instead.").emit();
}