X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=src%2Fcode%2Fearly-source-location.lisp;h=e7018e31c64efdebf050d48d3b41300cb9f00f93;hb=5d04a95274c9ddaebbcd6ddffc5d646e2c25598c;hp=022af85a17f697736f539c72f7cad3a618cdb39a;hpb=31f072311935e32751508ecf824905c6b58a1d95;p=sbcl.git

diff --git a/src/code/early-source-location.lisp b/src/code/early-source-location.lisp
index 022af85..e7018e3 100644
--- a/src/code/early-source-location.lisp
+++ b/src/code/early-source-location.lisp
@@ -12,6 +12,15 @@
 
 (in-package "SB!C")
 
+;;; Used as the CDR of the code coverage instrumentation records
+;;; (instead of NIL) to ensure that any well-behaving user code will
+;;; not have constants EQUAL to that record. This avoids problems with
+;;; the records getting coalesced with non-record conses, which then
+;;; get mutated when the instrumentation runs. Note that it's
+;;; important for multiple records for the same location to be
+;;; coalesced. -- JES, 2008-01-02
+(defconstant +code-coverage-unmarked+ '%code-coverage-unmarked%)
+
 (defvar *source-location-thunks* nil)
 
 ;; Should get called only in unusual circumstances. Normally handled