Start the binemit module.

This module will provide supporting code for emitting binary machine
code with relocations.

lib/cretonne/src/binemit/mod.rs

@@ -0,0 +1,33 @@
+//! Binary machine code emission.
+//!
+//! The `binemit` module contains code for translating Cretonne's intermediate representation into
+//! binary machine code.
+
+use ir::{FuncRef, JumpTable};
+
+/// Relocation kinds depend on the current ISA.
+pub struct Reloc(u16);
+
+/// Abstract interface for adding bytes to the code segment.
+///
+/// A `CodeSink` will receive all of the machine code for a function. It also accepts relocations
+/// which are locations in the code section that need to be fixed up when linking.
+pub trait CodeSink {
+    /// Add 1 byte to the code section.
+    fn put1(&mut self, u8);
+
+    /// Add 2 bytes to the code section.
+    fn put2(&mut self, u16);
+
+    /// Add 4 bytes to the code section.
+    fn put4(&mut self, u32);
+
+    /// Add 8 bytes to the code section.
+    fn put8(&mut self, u64);
+
+    /// Add a relocation referencing an external function at the current offset.
+    fn reloc_func(&mut self, Reloc, FuncRef);
+
+    /// Add a relocation referencing a jump table.
+    fn reloc_jt(&mut self, Reloc, JumpTable);
+}

lib/cretonne/src/lib.rs

@@ -10,6 +10,7 @@ pub use write::write_function;
 /// Version number of the cretonne crate.
 pub const VERSION: &'static str = env!("CARGO_PKG_VERSION");
 
+pub mod binemit;
 pub mod flowgraph;
 pub mod dominator_tree;
 pub mod entity_list;