split ffi crate to support distinct 16, 32, and 64-bit builds

initial work to optionally discard any instruction printing support

when using `-Z build-std` to fully remove .eh_frame, a stripped
long_mode_no_fmt .so is 61kb!

1 files changed, 20 insertions, 0 deletions

diff --git a/ffi/src/write_sink.rs b/ffi/src/write_sink.rs
new file mode 100644
index 0000000..b188498
--- /dev/null
+++ b/ffi/src/write_sink.rs
@@ -0,0 +1,20 @@
+pub struct InstructionSink<'buf> {
+    pub buf: &'buf mut [u8],
+    pub offs: usize,
+}
+
+impl<'a> core::fmt::Write for InstructionSink<'a> {
+    fn write_str(&mut self, s: &str) -> core::fmt::Result {
+        for b in s.bytes() {
+            if self.offs < self.buf.len() {
+                self.buf[self.offs] = b;
+                self.offs += 1;
+            } else {
+                break;
+            }
+        }
+
+        Ok(())
+    }
+}
+