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

1use std::collections::HashSet;
2
3use once_cell::sync::OnceCell;
4
5use rustc_middle::{mir::Local, ty::TyCtxt};
6use rustc_span::Span;
7
8use super::value_is_from_const;
9use crate::{
10    analysis::{
11        core::dataflow::{graph::*, *},
12        utils::def_path::DefPath,
13    },
14    utils::log::{relative_pos_range, span_to_filename, span_to_line_number, span_to_source_code},
15};
16use annotate_snippets::{Level, Renderer, Snippet};
17
18static DEFPATHS: OnceCell<DefPaths> = OnceCell::new();
19
20struct DefPaths {
21    string_new: DefPath,
22    string_push: DefPath,
23}
24
25impl DefPaths {
26    pub fn new(tcx: &TyCtxt<'_>) -> Self {
27        Self {
28            string_new: DefPath::new("std::string::String::new", tcx),
29            string_push: DefPath::new("std::string::String::push", tcx),
30        }
31    }
32}
33
34use crate::analysis::opt::OptCheck;
35
36pub struct StringPushCheck {
37    record: Vec<Span>,
38}
39
40fn extract_value_if_is_string_push(graph: &Graph, node: &GraphNode) -> Option<Local> {
41    let def_paths = DEFPATHS.get().unwrap();
42    for op in node.ops.iter() {
43        if let NodeOp::Call(def_id) = op {
44            if *def_id == def_paths.string_push.last_def_id() {
45                let push_value_idx = graph.edges[node.in_edges[1]].src; //the secod parameter
46                return Some(push_value_idx);
47            }
48        }
49    }
50    None
51}
52
53fn find_upside_string_new(graph: &Graph, node_idx: Local) -> Option<Local> {
54    let mut string_new_node_idx = None;
55    let def_paths = DEFPATHS.get().unwrap();
56    let mut node_operator = |graph: &Graph, idx: Local| -> DFSStatus {
57        let node = &graph.nodes[idx];
58        for op in node.ops.iter() {
59            if let NodeOp::Call(def_id) = op {
60                if *def_id == def_paths.string_new.last_def_id() {
61                    string_new_node_idx = Some(idx);
62                    return DFSStatus::Stop;
63                }
64            }
65        }
66        DFSStatus::Continue
67    };
68    let mut seen = HashSet::new();
69    graph.dfs(
70        node_idx,
71        Direction::Upside,
72        &mut node_operator,
73        &mut Graph::always_true_edge_validator,
74        false,
75        &mut seen,
76    );
77    string_new_node_idx
78}
79
80impl OptCheck for StringPushCheck {
81    fn new() -> Self {
82        Self { record: Vec::new() }
83    }
84
85    fn check(&mut self, graph: &Graph, tcx: &TyCtxt) {
86        let _ = &DEFPATHS.get_or_init(|| DefPaths::new(tcx));
87        for (node_idx, node) in graph.nodes.iter_enumerated() {
88            if let Some(pushed_value_idx) = extract_value_if_is_string_push(graph, node) {
89                if find_upside_string_new(graph, node_idx).is_some() {
90                    if !value_is_from_const(graph, pushed_value_idx) {
91                        self.record.clear(); // Warning: Not rigorous, push of other string may cause clear
92                        return;
93                    }
94                    self.record.push(node.span);
95                }
96            }
97        }
98    }
99
100    fn report(&self, graph: &Graph) {
101        if !self.record.is_empty() {
102            report_string_push_bug(graph, &self.record);
103        }
104    }
105
106    fn cnt(&self) -> usize {
107        self.record.len()
108    }
109}
110
111fn report_string_push_bug(graph: &Graph, spans: &Vec<Span>) {
112    let code_source = span_to_source_code(graph.span);
113    let filename = span_to_filename(graph.span);
114    let mut snippet = Snippet::source(&code_source)
115        .line_start(span_to_line_number(graph.span))
116        .origin(&filename)
117        .fold(true);
118    for span in spans.iter() {
119        snippet = snippet.annotation(
120            Level::Error
121                .span(relative_pos_range(graph.span, *span))
122                .label("Checked here."),
123        )
124    }
125    let message = Level::Warning
126        .title("Unnecessary encoding checkings detected")
127        .snippet(snippet)
128        .footer(Level::Help.title("Use unsafe APIs instead."));
129    let renderer = Renderer::styled();
130    println!("{}", renderer.render(message));
131}
rapx/analysis/opt/checking/encoding_checking/string_push.rs

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