std: Add debug::breakpoint

src/libstd/dbg.rs

@@ -9,6 +9,7 @@ export debug_tag;
 export debug_fn;
 export ptr_cast;
 export refcount;
+export breakpoint;
 
 #[abi = "cdecl"]
 native mod rustrt {
@@ -18,6 +19,7 @@ native mod rustrt {
     fn debug_tag(td: *sys::type_desc, x: *());
     fn debug_fn(td: *sys::type_desc, x: *());
     fn debug_ptrcast(td: *sys::type_desc, x: *()) -> *();
+    fn rust_dbg_breakpoint();
 }
 
 fn debug_tydesc<T>() {
@@ -51,6 +53,18 @@ fn refcount<T>(a: @T) -> uint unsafe {
     ret *p;
 }
 
+#[doc = "Triggers a debugger breakpoint"]
+fn breakpoint() {
+    rustrt::rust_dbg_breakpoint();
+}
+
+#[test]
+fn test_breakpoint_should_not_abort_process_when_not_under_gdb() {
+    // Triggering a breakpoint involves raising SIGTRAP, which terminates
+    // the process under normal circumstances
+    breakpoint();
+}
+
 // Local Variables:
 // mode: rust;
 // fill-column: 78;

src/rt/rust_builtin.cpp

@@ -805,6 +805,11 @@ rust_dbg_call(dbg_callback cb, void *data) {
     return cb(data);
 }
 
+extern "C" CDECL void
+rust_dbg_breakpoint() {
+    BREAKPOINT_AWESOME;
+}
+
 extern "C" CDECL rust_sched_id
 rust_osmain_sched_id() {
     rust_task *task = rust_get_current_task();

src/rt/rust_debug.h

@@ -7,6 +7,19 @@
 #include <string>
 #include <cstdlib>
 
+#ifndef _WIN32
+
+#include <signal.h>
+#define BREAKPOINT_AWESOME                      \
+    do {                                        \
+        signal(SIGTRAP, SIG_IGN);               \
+        raise(SIGTRAP);                         \
+    } while (0)
+
+#else
+#define BREAKPOINT_AWESOME
+#endif
+
 struct rust_task;
 
 namespace debug {

src/rt/rustrt.def.in

@@ -151,6 +151,7 @@ rust_dbg_lock_unlock
 rust_dbg_lock_wait
 rust_dbg_lock_signal
 rust_dbg_call
+rust_dbg_breakpoint
 rust_osmain_sched_id
 rust_compare_and_swap_ptr
 rust_atomic_increment