rapx/check/opt/checking/encoding_checking/
string_push.rs

1use super::value_is_from_const;
2use crate::analysis::dataflow::*;
3use rustc_middle::{mir::Local, ty::TyCtxt};
4use rustc_span::Span;
5
6use annotate_snippets::Level;
7
8use crate::check::opt::report::OptReport;
9
10crate::def_paths! {
11    string_new: "std::string::String::new",
12    string_push: "std::string::String::push",
13}
14
15use crate::check::opt::OptCheck;
16
17pub struct StringPushCheck {
18    record: Vec<Span>,
19}
20
21fn extract_value_if_is_string_push(graph: &Graph, node: &GraphNode) -> Option<Local> {
22    let def_paths = DEFPATHS.get().unwrap();
23    for op in node.ops.iter() {
24        if let NodeOp::Call(def_id) = op {
25            if *def_id == def_paths.string_push.last_def_id() {
26                let push_value_idx = graph.edges[node.in_edges[1]].src; //the secod parameter
27                return Some(push_value_idx);
28            }
29        }
30    }
31    None
32}
33
34fn find_upside_string_new(graph: &Graph, node_idx: Local) -> Option<Local> {
35    let def_paths = DEFPATHS.get().unwrap();
36    graph.find_first_node(
37        node_idx,
38        Direction::Upside,
39        &mut |graph: &Graph, idx: Local| {
40            let node = &graph.nodes[idx];
41            for op in node.ops.iter() {
42                if let NodeOp::Call(def_id) = op {
43                    if *def_id == def_paths.string_new.last_def_id() {
44                        return true;
45                    }
46                }
47            }
48            false
49        },
50        &mut Graph::always_true_edge_validator,
51    )
52}
53
54impl OptCheck for StringPushCheck {
55    fn new() -> Self {
56        Self { record: Vec::new() }
57    }
58
59    fn check(&mut self, graph: &Graph, tcx: &TyCtxt) {
60        DEFPATHS.get_or_init(|| DefPaths::new(tcx));
61        for (node_idx, node) in graph.nodes.iter_enumerated() {
62            if let Some(pushed_value_idx) = extract_value_if_is_string_push(graph, node) {
63                if find_upside_string_new(graph, node_idx).is_some() {
64                    if !value_is_from_const(graph, pushed_value_idx) {
65                        self.record.clear(); // Warning: Not rigorous, push of other string may cause clear
66                        return;
67                    }
68                    self.record.push(node.span);
69                }
70            }
71        }
72    }
73
74    fn report(&self, graph: &Graph) {
75        if !self.record.is_empty() {
76            report_string_push_bug(graph, &self.record);
77        }
78    }
79
80    fn cnt(&self) -> usize {
81        self.record.len()
82    }
83}
84
85fn report_string_push_bug(graph: &Graph, spans: &Vec<Span>) {
86    let mut report = OptReport::from_graph(graph).title("Unnecessary encoding checkings detected");
87    for span in spans.iter() {
88        report = report.annotate(Level::Error, *span, "Checked here.");
89    }
90    report.footer("Use unsafe APIs instead.").emit();
91}
rapx/check/opt/checking/encoding_checking/string_push.rs

rapx/check/opt/checking/encoding_checking/
string_push.rs
