orca_wasm/ir/module/
module_tables.rs

1//! Intermediate representation of the Tables in a Module
2
3use crate::ir::id::TableID;
4use wasmparser::{RefType, TableType};
5
6/// Tables Section of a module
7#[derive(Clone, Debug, Default)]
8pub struct ModuleTables<'a> {
9    tables: Vec<(TableType, Option<wasmparser::ConstExpr<'a>>)>,
10}
11
12impl<'a> ModuleTables<'a> {
13    /// Create a new table section
14    pub fn new(tables: Vec<(TableType, Option<wasmparser::ConstExpr<'a>>)>) -> Self {
15        ModuleTables { tables }
16    }
17
18    /// Check if there are any tables
19    pub fn is_empty(&self) -> bool {
20        self.tables.is_empty()
21    }
22
23    /// Create an iterable over the table section
24    pub fn iter(&self) -> std::slice::Iter<'_, (TableType, Option<wasmparser::ConstExpr<'a>>)> {
25        self.tables.iter()
26    }
27
28    /// Finds a unique function table in a module.
29    ///
30    /// Modules produced by compilers like LLVM typically have one function
31    /// table for indirect function calls. This function will look for a single
32    /// function table inside this module, and return that if found. If no
33    /// function tables are present `None` will be returned
34    ///
35    /// # Errors
36    ///
37    /// Returns an error if there are two function tables in this module
38    ///
39    /// Inspired from [walrus' implementation]
40    ///
41    /// [walrus' implementation]: https://docs.rs/walrus/latest/walrus/struct.ModuleTables.html#method.main_function_table
42    pub fn main_function(&self) -> Option<TableID> {
43        let mut tables = self
44            .tables
45            .iter()
46            .enumerate()
47            .filter(|(_, (t, _))| t.element_type == RefType::FUNCREF);
48        let id = match tables.next() {
49            Some((index, _)) => Some(TableID(index as u32)),
50            None => return None,
51        };
52        if tables.next().is_some() {
53            panic!("module contains more than one function table");
54        }
55        id
56    }
57
58    /// Get a table
59    pub fn get(&self, table_id: TableID) -> Option<TableType> {
60        if *table_id < self.tables.len() as u32 {
61            return Some(self.tables[*table_id as usize].0);
62        }
63        None
64    }
65
66    /// Get a mutable reference to a table
67    pub fn get_mut(&mut self, table_id: TableID) -> &mut TableType {
68        if *table_id < self.tables.len() as u32 {
69            return &mut self.tables[*table_id as usize].0;
70        }
71        panic!("Invalid Table ID")
72    }
73}
orca_wasm/ir/module/module_tables.rs

orca_wasm/ir/module/
module_tables.rs
