add support for absolute relocations

crates/linker/src/lib.rs

@@ -372,3 +372,44 @@ pub(crate) fn open_mmap_mut(path: &Path, length: usize) -> MmapMut {
 
     unsafe { MmapMut::map_mut(&out_file).unwrap_or_else(|e| internal_error!("{e}")) }
 }
+
+/// # dbg_hex
+/// display dbg result in hexadecimal `{:#x?}` format.
+///
+/// # usage
+/// Replace `dbg!()` with `dbg_hex!()`
+///
+/// # example
+/// ```rust, no_run
+/// use dbg_hex::dbg_hex;
+/// dbg_hex!(0x16 + 0x16);
+/// ```
+///
+/// output
+/// ```text
+/// [src/lib.rs:38] 0x16 + 0x16 = 0x2c
+/// ```
+#[macro_export]
+macro_rules! dbg_hex {
+    // NOTE: We cannot use `concat!` to make a static string as a format argument
+    // of `eprintln!` because `file!` could contain a `{` or
+    // `$val` expression could be a block (`{ .. }`), in which case the `eprintln!`
+    // will be malformed.
+    () => {
+        eprintln!("[{}:{}]", file!(), line!());
+    };
+    ($val:expr $(,)?) => {
+        // Use of `match` here is intentional because it affects the lifetimes
+        // of temporaries - https://stackoverflow.com/a/48732525/1063961
+        match $val {
+            tmp => {
+                eprintln!("[{}:{}] {} = {:#x?}",
+                    file!(), line!(), stringify!($val), &tmp);
+                tmp
+            }
+        }
+    };
+    ($($val:expr),+ $(,)?) => {
+        ($($crate::dbg_hex!($val)),+,)
+    };
+}