leo_passes/static_analysis/
await_checker.rs

1// Copyright (C) 2019-2025 Provable Inc.
2// This file is part of the Leo library.
3
4// The Leo library is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8
9// The Leo library is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12// GNU General Public License for more details.
13
14// You should have received a copy of the GNU General Public License
15// along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
16
17use crate::ConditionalTreeNode;
18use indexmap::IndexSet;
19use leo_ast::Identifier;
20use leo_errors::StaticAnalyzerWarning;
21use leo_span::{Span, Symbol};
22
23// TODO: Could optimize by removing duplicate paths (if set of futures is the same).
24pub struct AwaitChecker {
25    /// All possible subsets of futures that must be awaited.
26    pub(crate) to_await: Vec<ConditionalTreeNode>,
27    /// Statically updated set of futures to await.
28    pub(crate) static_to_await: IndexSet<Symbol>,
29}
30
31impl AwaitChecker {
32    /// Initializes a new `AwaitChecker`.
33    pub fn new() -> Self {
34        Self { to_await: Vec::new(), static_to_await: IndexSet::new() }
35    }
36
37    /// Remove from list.
38    /// Returns `true` if there was a path where the future was not awaited in the order of the input list.
39    pub fn remove(&mut self, id: &Identifier) -> bool {
40        // Can assume in finalize block.
41        // Remove from dynamic list.
42        let is_not_first = self.to_await.iter_mut().any(|node| node.remove_element(&id.name));
43
44        // Remove from static list.
45        self.static_to_await.shift_remove(&id.name);
46
47        is_not_first
48    }
49
50    /// Initialize futures.
51    pub fn set_futures(&mut self, futures: IndexSet<Symbol>) {
52        if futures.is_empty() {
53            self.to_await = Vec::new();
54        } else {
55            self.to_await = vec![ConditionalTreeNode::new(futures.clone())];
56        }
57        self.static_to_await = futures;
58    }
59
60    /// Enter scope for `then` branch of conditional.
61    pub fn create_then_scope(
62        &mut self,
63        is_finalize: bool,
64        _input: Span,
65    ) -> Result<Vec<ConditionalTreeNode>, StaticAnalyzerWarning> {
66        if is_finalize {
67            let mut current_nodes = Vec::new();
68            // Extend all paths by one node to represent the upcoming `then` branch.
69            for node in self.to_await.iter() {
70                // Extend current path.
71                current_nodes.push(node.clone().create_child());
72            }
73            // Update the set of nodes to be current set.
74            self.to_await = current_nodes.clone();
75            Ok(current_nodes)
76        } else {
77            Ok(Vec::new())
78        }
79    }
80
81    /// Exit scope for `then` branch of conditional.
82    pub fn exit_then_scope(
83        &mut self,
84        is_finalize: bool,
85        parent_nodes: Vec<ConditionalTreeNode>,
86    ) -> Vec<ConditionalTreeNode> {
87        // Check if a nested conditional statement signaled their existence.
88        if is_finalize { core::mem::replace(&mut self.to_await, parent_nodes) } else { Vec::new() }
89    }
90
91    /// Exit scope for conditional statement at current depth.
92    pub fn exit_statement_scope(&mut self, is_finalize: bool, then_nodes: Vec<ConditionalTreeNode>) {
93        if is_finalize {
94            // Merge together the current set of nodes (from `otherwise` branch) with `then` nodes.
95            self.to_await.extend(then_nodes);
96        }
97    }
98}
leo_passes/static_analysis/await_checker.rs

leo_passes/static_analysis/
await_checker.rs
