From 8ca27aeeb99a0da43e92e39918aa07c0b1443c07 Mon Sep 17 00:00:00 2001
From: Johannes Stoelp <johannes.stoelp@gmail.com>
Date: Thu, 19 Dec 2024 19:47:19 +0100
Subject: rt: remove dump() and add disasm(), to directly disasm code using
ndisasm if available
---
src/rt.rs | 55 ++++++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 44 insertions(+), 11 deletions(-)
(limited to 'src')
diff --git a/src/rt.rs b/src/rt.rs
index 4c4309b..a47cada 100644
--- a/src/rt.rs
+++ b/src/rt.rs
@@ -156,22 +156,55 @@ impl Runtime {
unsafe { Self::as_fn::<F>(fn_start) }
}
- /// Dump the code added so far to the runtime into a file called `jit.asm` in the processes
- /// current working directory.
- ///
- /// The code can be inspected with a disassembler as for example `ndiasm` from
- /// [nasm.us](https://nasm.us/index.php).
- /// ```sh
- /// ndisasm -b 64 jit.asm
- /// ```
+ /// 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 writing the file failed.
- pub fn dump(&self) {
+ /// Panics if anything goes wrong with spawning, writing to or reading from
+ /// 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) };
- std::fs::write("jit.asm", code).expect("Failed to write file");
+
+ // 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
+ )
+ );
}
/// Reinterpret the block of code pointed to by `fn_start` as `F`.
--
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