X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Fbsd-os.h;h=1cdc422f82fffbe9248e08afb7c7c3be5ac42c24;hb=e02c32bd4d07a7d30c9a9d78be54f1f9f84f9877;hp=de568f869a81604f3c813f73173a56f2c5671c9d;hpb=cea4896b2482b7b2b429c1631d774b4cfbc0efba;p=sbcl.git

diff --git a/src/runtime/bsd-os.h b/src/runtime/bsd-os.h
index de568f8..1cdc422 100644
--- a/src/runtime/bsd-os.h
+++ b/src/runtime/bsd-os.h
@@ -28,6 +28,15 @@ typedef int os_vm_prot_t;
  * original FreeBSD port of SBCL, that's wrong, it's actually a
  * ucontext_t. */
 typedef ucontext_t os_context_t;
+/* KLUDGE: A hack inherited from CMU CL used to be conditional on
+ * !defined(__linux__), and has now been made conditional on
+ * CANNOT_GET_TO_SINGLE_STEP_FLAG: if the OS won't let us flip the
+ * single-step flag bit in the state stored in a signal context, then
+ * we need to mess around with overwriting preceding code with
+ * bit-flipping code. This isn't needed in Linux or OpenBSD; I haven't
+ * been able to test whether it's still needed in FreeBSD, so for
+ * conservatism it's left in. -- WHN 2000-10-24 */
+#define CANNOT_GET_TO_SINGLE_STEP_FLAG
 #elif defined __OpenBSD__
 typedef struct sigcontext os_context_t;
 #else