0.8.15:

If the heuristic doesn't work, the displayed source will be wrong, but will

probably be near the actual source.  If the ``shape'' of the top-level form in

the source file is too different from the original form, then an error will be

signaled.  When the heuristic is used, the the source location commands are

signaled.  When the heuristic is used, the source location commands are

noticeably slowed.

Source location printing can also be confused if (after the source was

@item The block start location may be the same as the true location.

@item The block start location will never be later in the the

@item The block start location will never be later in the 

program's flow of control than the true location.

@item No conditional control structures (such as @code{if},

@c @cindex Breakpoints

@c SBCL supports setting of breakpoints inside compiled functions and

@c stepping of compiled code.  Breakpoints can only be set at at known

@c stepping of compiled code.  Breakpoints can only be set at known

@c locations (@pxref{Unknown Locations and Interrupts}), so these

@c commands are largely useless unless the @code{debug} optimize quality

@c is at least @code{2} (@pxref{Debugger Policy Control}).  These

  (move ecx esi)

  (inst sub ecx esp-tn)

  ;; Check for all the args fitting the the registers.

  ;; Check for all the args fitting the registers.

  (inst cmp ecx (fixnumize 3))

  (inst jmp :le REGISTER-ARGS)

  ;; CMU CL, there are two distinct -- but coupled -- mechanisms to

  ;; finding the name of a function. The slot here is one mechanism

  ;; (used in CMU CL to look up names in the debugger, e.g. in

  ;; BACKTRACE). The other mechanism is the the NAME slot in function

  ;; BACKTRACE). The other mechanism is the NAME slot in function

  ;; primitive objects (used in CMU CL to look up names elsewhere,

  ;; e.g. in CL:FUNCTION-LAMBDA-EXPRESSION and in CL:DESCRIBE).

  ;;

    (values)))

;;; Print a breakdown by instance type of all the instances allocated

;;; in SPACE. If TOP-N is true, print only information for the the

;;; in SPACE. If TOP-N is true, print only information for the 

;;; TOP-N types with largest usage.

(defun instance-usage (space &key (top-n 15))

  (declare (type spaces space) (type (or fixnum null) top-n))

;;; UNIX-WRITE accepts a file descriptor, a buffer, an offset, and the

;;; length to write. It attempts to write len bytes to the device

;;; associated with fd from the the buffer starting at offset. It returns

;;; associated with fd from the buffer starting at offset. It returns

;;; the actual number of bytes written.

(defun unix-write (fd buf offset len)

  (declare (type unix-fd fd)