From c0d4e88428296b8da6f2616f47c760b32abf66ed Mon Sep 17 00:00:00 2001
From: Graydon Hoare <graydon@mozilla.com>
Date: Fri, 31 Dec 2010 10:35:39 -0800
Subject: [PATCH] Add std.dbg.trap(str msg) for help debugging.

---
 src/lib/dbg.rs          | 5 +++++
 src/rt/rust_builtin.cpp | 8 ++++++++
 2 files changed, 13 insertions(+)

diff --git a/src/lib/dbg.rs b/src/lib/dbg.rs
index 51a31e07d13..774052dcaf5 100644
--- a/src/lib/dbg.rs
+++ b/src/lib/dbg.rs
@@ -18,6 +18,7 @@ native "rust" mod rustrt {
     fn debug_obj[T](&T x, uint nmethods, uint nbytes);
     fn debug_fn[T](&T x);
     fn debug_ptrcast[T, U](@T x) -> @U;
+    fn debug_trap(str msg);
 }
 
 fn debug_vec[T](vec[T] v) {
@@ -61,6 +62,10 @@ fn ptr_cast[T, U](@T x) -> @U {
     ret rustrt.debug_ptrcast[T, U](x);
 }
 
+fn trap(str s) {
+    rustrt.debug_trap(s);
+}
+
 // Local Variables:
 // mode: rust;
 // fill-column: 78;
diff --git a/src/rt/rust_builtin.cpp b/src/rt/rust_builtin.cpp
index cb16fbf067d..84111d826e7 100644
--- a/src/rt/rust_builtin.cpp
+++ b/src/rt/rust_builtin.cpp
@@ -363,6 +363,14 @@ debug_ptrcast(rust_task *task,
     return ptr;
 }
 
+extern "C" CDECL void
+debug_trap(rust_task *task, rust_str *s)
+{
+    task->log(rust_log::STDLIB, "trapping: %s", s->data);
+    // FIXME: x86-ism.
+    __asm__("int3");
+}
+
 
 //
 // Local Variables: