diff --git a/src/etc/indenter b/src/etc/indenter
new file mode 100755
index 00000000000..db0009fd0b6
--- /dev/null
+++ b/src/etc/indenter
@@ -0,0 +1,17 @@
+#!/usr/bin/perl -w
+
+$ident = 0;
+while (<>) {
+    if (/^rust: ">>/) {
+        $indent += 1;
+    } elsif (/^rust: "<</) {
+        $indent -= 1;
+    }
+
+    printf "%03d  ", $indent;
+    for ($i = 0; $i < $indent; $i++) {
+        printf("  ");
+    }
+    print;
+}
+
diff --git a/src/rustc/util/common.rs b/src/rustc/util/common.rs
index 1a6b7b0ccf9..9c666beb54d 100644
--- a/src/rustc/util/common.rs
+++ b/src/rustc/util/common.rs
@@ -5,6 +5,24 @@ import syntax::codemap::{span};
 import syntax::visit;
 import syntax::print;
 
+fn indent<R>(op: fn() -> R) -> R {
+    // Use in conjunction with the log post-processor like `src/etc/indenter`
+    // to make debug output more readable.
+    #debug[">>"];
+    let r <- op();
+    #debug["<< (Result = %?)", r];
+    ret r;
+}
+
+resource _indenter(_i: ()) {
+    #debug["<<"];
+}
+
+fn indenter() -> _indenter {
+    #debug[">>"];
+    _indenter(())
+}
+
 type flag = hashmap<str, ()>;
 
 fn def_eq(a: ast::def_id, b: ast::def_id) -> bool {