Copyright (C) 1995, Digital Equipment Corporation
All rights reserved.
See the file COPYRIGHT for a full description.
Last modified on Thu May 4 09:11:40 PDT 1995 by kalsow
modified on Thu Jun 25 18:20:47 PDT 1992 by muller
UNSAFE INTERFACE RTStack;
IMPORT RTMachine;
This interface defines the low-level routines used to traverse
the runtime stack. Not all platforms support these routines.
CONST Has_walker = RTMachine.Has_stack_walker;
Indicates whether this platform has a stack walker. If Has_walker
is FALSE, it is a checked runtime error to call any of the routines
described below.
TYPE Frame = RTMachine.FrameInfo;
A machine-dependent type that minimally includes fields named pc
and sp.
<*EXTERNAL "RTStack__GetThreadFrame" *>
PROCEDURE GetThreadFrame (VAR(*OUT*) f: Frame; start: ADDRESS; len: INTEGER);
Return in f the frame of the thread whose machine state is in bytes
[start .. start+len). Returns with f.pc=NIL on failure.
<*EXTERNAL "RTStack__CurFrame" *>
PROCEDURE CurrentFrame (VAR(*OUT*) f: Frame);
Return in f the frame of its caller. Returns with f.pc=NIL on failure.
<*EXTERNAL "RTStack__PrevFrame" *>
PROCEDURE PreviousFrame (READONLY callee: Frame; VAR(*OUT*)caller: Frame);
Return in caller the stack frame that called callee.
Returns with pc = NIL if callee is the first frame on
the stack or its predecessor is ill-formed.
<*EXTERNAL "RTStack__Unwind" *>
PROCEDURE Unwind (READONLY f: Frame);
Restore the machine state back to the frame f. All callee-saved
registers must be restored to the state they were in when frame f
made its last call. Note that if the unwind operation encounters a
signal handler frame, it must also restore the caller-saved registers.
<*EXTERNAL "RTStack__ProcName" *>
PROCEDURE ProcName (READONLY f: Frame): ADDRESS;
Return the null-terminated constant string that names the procedure
corresponding to the stack frame f. Returns NIL if no name is
known.
END RTStack.