disasm: move out and implement on asm/rt

4 files changed, 66 insertions, 38 deletions

diff --git a/src/asm.rs b/src/asm.rs
index 8647e83..1790e4e 100644
--- a/src/asm.rs
+++ b/src/asm.rs
@@ -42,6 +42,19 @@ impl Asm {
         self.buf
     }
 
+    /// Disassemble the code currently added to the runtime, using
+    /// [`ndisasm`](https://nasm.us/index.php) and print it to _stdout_. If
+    /// `ndisasm` is not available on the system this prints a warning and
+    /// becomes a nop.
+    ///
+    /// # Panics
+    ///
+    /// Panics if anything goes wrong with spawning, writing to or reading from
+    /// the `ndisasm` child process.
+    pub fn disasm(&self) {
+        crate::disasm::disasm(&self.buf);
+    }
+
     /// Emit a slice of bytes.
     pub(crate) fn emit(&mut self, bytes: &[u8]) {
         self.buf.extend_from_slice(bytes);
diff --git a/src/disasm.rs b/src/disasm.rs
new file mode 100644
index 0000000..d8e6058
--- /dev/null
+++ b/src/disasm.rs
@@ -0,0 +1,51 @@
+use std::io::{ErrorKind, Write};
+use std::process::{Command, Stdio};
+
+/// Disassemble the code currently added to the runtime, using
+/// [`ndisasm`](https://nasm.us/index.php) and print it to _stdout_. If
+/// `ndisasm` is not available on the system this prints a warning and
+/// becomes a nop.
+///
+/// # Panics
+///
+/// Panics if anything goes wrong with spawning, writing to or reading from
+/// the `ndisasm` child process.
+pub(crate) fn disasm<T: AsRef<[u8]>>(code: T) {
+    let code = code.as_ref();
+
+    // Create ndisasm process, which expects input on stdin.
+    let mut child = match Command::new("ndisasm")
+        .args(["-b64", "-"])
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .spawn()
+    {
+        Ok(child) => child,
+        Err(err) if err.kind() == ErrorKind::NotFound => {
+            println!("disasm: skipping, ndisasm not found");
+            return;
+        }
+        Err(err) => {
+            panic!("{:?}", err);
+        }
+    };
+
+    // Write code to stdin of ndisasm.
+    child
+        .stdin
+        .take()
+        .expect("failed to take stdin")
+        .write_all(code)
+        .expect("failed to write bytes to stdin");
+
+    // Wait for output from ndisasm and print to stdout.
+    println!(
+        "{}",
+        String::from_utf8_lossy(
+            &child
+                .wait_with_output()
+                .expect("failed to get stdout")
+                .stdout
+        )
+    );
+}
diff --git a/src/lib.rs b/src/lib.rs
index ef49859..201a10f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -74,6 +74,7 @@
 //! ```
 
 mod asm;
+mod disasm;
 mod imm;
 mod label;
 mod mem;
diff --git a/src/rt.rs b/src/rt.rs
index a47cada..76a34b1 100644
--- a/src/rt.rs
+++ b/src/rt.rs
@@ -167,44 +167,7 @@ impl Runtime {
     /// the `ndisasm` child process.
     pub fn disasm(&self) {
         assert!(self.idx <= self.len);
-        let code = unsafe { core::slice::from_raw_parts(self.buf, self.idx) };
-
-        // Create ndisasm process, which expects input on stdin.
-        let mut child = match std::process::Command::new("ndisasm")
-            .args(["-b64", "-"])
-            .stdin(std::process::Stdio::piped())
-            .stdout(std::process::Stdio::piped())
-            .spawn()
-        {
-            Ok(child) => child,
-            Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
-                println!("Runtime::disasm: ndisasm not found, skipping!");
-                return;
-            }
-            Err(err) => {
-                panic!("{:?}", err);
-            }
-        };
-
-        // Write code to stdin of ndisasm.
-        use std::io::Write;
-        child
-            .stdin
-            .take()
-            .expect("failed to take stdin")
-            .write_all(code)
-            .expect("failed to write bytes to stdin");
-
-        // Wait for output from ndisasm and print to stdout.
-        println!(
-            "{}",
-            String::from_utf8_lossy(
-                &child
-                    .wait_with_output()
-                    .expect("failed to get stdout")
-                    .stdout
-            )
-        );
+        crate::disasm::disasm(unsafe { core::slice::from_raw_parts(self.buf, self.idx) });
     }
 
     /// Reinterpret the block of code pointed to by `fn_start` as `F`.