moved crates in lib/ to src/, renamed crates, modified some files' text (#660)

moved crates in lib/ to src/, renamed crates, modified some files' text (#660)

cranelift/codegen/src/ir/jumptable.rs

@@ -0,0 +1,119 @@
+//! Jump table representation.
+//!
+//! Jump tables are declared in the preamble and assigned an `ir::entities::JumpTable` reference.
+//! The actual table of destinations is stored in a `JumpTableData` struct defined in this module.
+
+use crate::ir::entities::Ebb;
+use core::fmt::{self, Display, Formatter};
+use core::slice::{Iter, IterMut};
+use std::vec::Vec;
+
+/// Contents of a jump table.
+///
+/// All jump tables use 0-based indexing and densely populated.
+#[derive(Clone)]
+pub struct JumpTableData {
+    // Table entries.
+    table: Vec<Ebb>,
+}
+
+impl JumpTableData {
+    /// Create a new empty jump table.
+    pub fn new() -> Self {
+        Self { table: Vec::new() }
+    }
+
+    /// Create a new empty jump table with the specified capacity.
+    pub fn with_capacity(capacity: usize) -> Self {
+        Self {
+            table: Vec::with_capacity(capacity),
+        }
+    }
+
+    /// Get the number of table entries.
+    pub fn len(&self) -> usize {
+        self.table.len()
+    }
+
+    /// Append a table entry.
+    pub fn push_entry(&mut self, dest: Ebb) {
+        self.table.push(dest)
+    }
+
+    /// Checks if any of the entries branch to `ebb`.
+    pub fn branches_to(&self, ebb: Ebb) -> bool {
+        self.table.iter().any(|target_ebb| *target_ebb == ebb)
+    }
+
+    /// Access the whole table as a slice.
+    pub fn as_slice(&self) -> &[Ebb] {
+        self.table.as_slice()
+    }
+
+    /// Access the whole table as a mutable slice.
+    pub fn as_mut_slice(&mut self) -> &mut [Ebb] {
+        self.table.as_mut_slice()
+    }
+
+    /// Returns an iterator over the table.
+    pub fn iter(&self) -> Iter<Ebb> {
+        self.table.iter()
+    }
+
+    /// Returns an iterator that allows modifying each value.
+    pub fn iter_mut(&mut self) -> IterMut<Ebb> {
+        self.table.iter_mut()
+    }
+}
+
+impl Display for JumpTableData {
+    fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
+        write!(fmt, "jump_table [")?;
+        match self.table.first() {
+            None => (),
+            Some(first) => write!(fmt, "{}", first)?,
+        }
+        for ebb in self.table.iter().skip(1) {
+            write!(fmt, ", {}", ebb)?;
+        }
+        write!(fmt, "]")
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::JumpTableData;
+    use crate::entity::EntityRef;
+    use crate::ir::Ebb;
+    use std::string::ToString;
+
+    #[test]
+    fn empty() {
+        let jt = JumpTableData::new();
+
+        assert_eq!(jt.as_slice().get(0), None);
+        assert_eq!(jt.as_slice().get(10), None);
+
+        assert_eq!(jt.to_string(), "jump_table []");
+
+        let v = jt.as_slice();
+        assert_eq!(v, []);
+    }
+
+    #[test]
+    fn insert() {
+        let e1 = Ebb::new(1);
+        let e2 = Ebb::new(2);
+
+        let mut jt = JumpTableData::new();
+
+        jt.push_entry(e1);
+        jt.push_entry(e2);
+        jt.push_entry(e1);
+
+        assert_eq!(jt.to_string(), "jump_table [ebb1, ebb2, ebb1]");
+
+        let v = jt.as_slice();
+        assert_eq!(v, [e1, e2, e1]);
+    }
+}