lib/codegen-meta moved into lib/codegen. (#423)

* lib/codegen-meta moved into lib/codegen.

* Renamed codegen-meta and existing meta.

lib/codegen/meta/src/base/mod.rs

@@ -0,0 +1,3 @@
+//! Definitions for the base Cranelift language.
+
+pub mod types;

lib/codegen/meta/src/base/types.rs

@@ -0,0 +1,188 @@
+//! This module predefines all the Cranelift scalar types.
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum Bool {
+    /// 1-bit bool.
+    B1 = 1,
+    /// 8-bit bool.
+    B8 = 8,
+    /// 16-bit bool.
+    B16 = 16,
+    /// 32-bit bool.
+    B32 = 32,
+    /// 64-bit bool.
+    B64 = 64,
+}
+
+/// This provides an iterator through all of the supported bool variants.
+pub struct BoolIterator {
+    index: u8,
+}
+
+impl BoolIterator {
+    pub fn new() -> Self {
+        Self { index: 0 }
+    }
+}
+
+impl Iterator for BoolIterator {
+    type Item = Bool;
+    fn next(&mut self) -> Option<Self::Item> {
+        let res = match self.index {
+            0 => Some(Bool::B1),
+            1 => Some(Bool::B8),
+            2 => Some(Bool::B16),
+            3 => Some(Bool::B32),
+            4 => Some(Bool::B64),
+            _ => return None,
+        };
+        self.index += 1;
+        res
+    }
+}
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum Int {
+    /// 8-bit int.
+    I8 = 8,
+    /// 16-bit int.
+    I16 = 16,
+    /// 32-bit int.
+    I32 = 32,
+    /// 64-bit int.
+    I64 = 64,
+}
+
+/// This provides an iterator through all of the supported int variants.
+pub struct IntIterator {
+    index: u8,
+}
+
+impl IntIterator {
+    pub fn new() -> Self {
+        Self { index: 0 }
+    }
+}
+
+impl Iterator for IntIterator {
+    type Item = Int;
+    fn next(&mut self) -> Option<Self::Item> {
+        let res = match self.index {
+            0 => Some(Int::I8),
+            1 => Some(Int::I16),
+            2 => Some(Int::I32),
+            3 => Some(Int::I64),
+            _ => return None,
+        };
+        self.index += 1;
+        res
+    }
+}
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum Float {
+    F32 = 32,
+    F64 = 64,
+}
+
+/// Iterator through the variants of the Float enum.
+pub struct FloatIterator {
+    index: u8,
+}
+
+impl FloatIterator {
+    pub fn new() -> Self {
+        Self { index: 0 }
+    }
+}
+
+/// This provides an iterator through all of the supported float variants.
+impl Iterator for FloatIterator {
+    type Item = Float;
+    fn next(&mut self) -> Option<Self::Item> {
+        let res = match self.index {
+            0 => Some(Float::F32),
+            1 => Some(Float::F64),
+            _ => return None,
+        };
+        self.index += 1;
+        res
+    }
+}
+
+/// A type representing CPU flags.
+///
+/// Flags can't be stored in memory.
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum Flag {
+    /// CPU flags from an integer comparison.
+    IFlags,
+    /// CPU flags from a floating point comparison.
+    FFlags,
+}
+
+/// Iterator through the variants of the Flag enum.
+pub struct FlagIterator {
+    index: u8,
+}
+
+impl FlagIterator {
+    pub fn new() -> Self {
+        Self { index: 0 }
+    }
+}
+
+impl Iterator for FlagIterator {
+    type Item = Flag;
+    fn next(&mut self) -> Option<Self::Item> {
+        let res = match self.index {
+            0 => Some(Flag::IFlags),
+            1 => Some(Flag::FFlags),
+            _ => return None,
+        };
+        self.index += 1;
+        res
+    }
+}
+
+#[cfg(test)]
+mod iter_tests {
+    use super::*;
+
+    #[test]
+    fn bool_iter_works() {
+        let mut bool_iter = BoolIterator::new();
+        assert_eq!(bool_iter.next(), Some(Bool::B1));
+        assert_eq!(bool_iter.next(), Some(Bool::B8));
+        assert_eq!(bool_iter.next(), Some(Bool::B16));
+        assert_eq!(bool_iter.next(), Some(Bool::B32));
+        assert_eq!(bool_iter.next(), Some(Bool::B64));
+        assert_eq!(bool_iter.next(), None);
+    }
+
+    #[test]
+    fn int_iter_works() {
+        let mut int_iter = IntIterator::new();
+        assert_eq!(int_iter.next(), Some(Int::I8));
+        assert_eq!(int_iter.next(), Some(Int::I16));
+        assert_eq!(int_iter.next(), Some(Int::I32));
+        assert_eq!(int_iter.next(), Some(Int::I64));
+        assert_eq!(int_iter.next(), None);
+    }
+
+    #[test]
+    fn float_iter_works() {
+        let mut float_iter = FloatIterator::new();
+        assert_eq!(float_iter.next(), Some(Float::F32));
+        assert_eq!(float_iter.next(), Some(Float::F64));
+        assert_eq!(float_iter.next(), None);
+    }
+
+    #[test]
+    fn flag_iter_works() {
+        let mut flag_iter = FlagIterator::new();
+        assert_eq!(flag_iter.next(), Some(Flag::IFlags));
+        assert_eq!(flag_iter.next(), Some(Flag::FFlags));
+        assert_eq!(flag_iter.next(), None);
+    }
+}