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

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