--- /dev/null
+/* Representation of stack frame debug information
+ * Copyright (C) 1996,1997,2000,2001, 2006, 2007, 2008 Free Software Foundation
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+
+\f
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libguile/_scm.h"
+#include "libguile/eval.h"
+#include "libguile/debug.h"
+#include "libguile/continuations.h"
+#include "libguile/struct.h"
+#include "libguile/macros.h"
+#include "libguile/procprop.h"
+#include "libguile/modules.h"
+#include "libguile/root.h"
+#include "libguile/strings.h"
+
+#include "libguile/validate.h"
+#include "libguile/stacks.h"
+
+\f
+/* {Frames and stacks}
+ *
+ * The debugging evaluator creates debug frames on the stack. These
+ * are linked from the innermost frame and outwards. The last frame
+ * created can always be accessed as SCM_LAST_DEBUG_FRAME.
+ * Continuations contain a pointer to the innermost debug frame on the
+ * continuation stack.
+ *
+ * Each debug frame contains a set of flags and information about one
+ * or more stack frames. The case of multiple frames occurs due to
+ * tail recursion. The maximal number of stack frames which can be
+ * recorded in one debug frame can be set dynamically with the debug
+ * option FRAMES.
+ *
+ * Stack frame information is of two types: eval information (the
+ * expression being evaluated and its environment) and apply
+ * information (the procedure being applied and its arguments). A
+ * stack frame normally corresponds to an eval/apply pair, but macros
+ * and special forms (which are implemented as macros in Guile) only
+ * have eval information and apply calls leads to apply only frames.
+ *
+ * Since we want to record the total stack information and later
+ * manipulate this data at the scheme level in the debugger, we need
+ * to transform it into a new representation. In the following code
+ * section you'll find the functions implementing this data type.
+ *
+ * Representation:
+ *
+ * The stack is represented as a struct with an id slot and a tail
+ * array of scm_t_info_frame structs.
+ *
+ * A frame is represented as a pair where the car contains a stack and
+ * the cdr an inum. The inum is an index to the first SCM value of
+ * the scm_t_info_frame struct.
+ *
+ * Stacks
+ * Constructor
+ * make-stack
+ * Selectors
+ * stack-id
+ * stack-ref
+ * Inspector
+ * stack-length
+ *
+ * Frames
+ * Constructor
+ * last-stack-frame
+ * Selectors
+ * frame-number
+ * frame-source
+ * frame-procedure
+ * frame-arguments
+ * frame-previous
+ * frame-next
+ * Predicates
+ * frame-real?
+ * frame-procedure?
+ * frame-evaluating-args?
+ * frame-overflow? */
+
+\f
+
+/* Some auxiliary functions for reading debug frames off the stack.
+ */
+
+/* Stacks often contain pointers to other items on the stack; for
+ example, each scm_t_debug_frame structure contains a pointer to the
+ next frame out. When we capture a continuation, we copy the stack
+ into the heap, and just leave all the pointers unchanged. This
+ makes it simple to restore the continuation --- just copy the stack
+ back! However, if we retrieve a pointer from the heap copy to
+ another item that was originally on the stack, we have to add an
+ offset to the pointer to discover the new referent.
+
+ If PTR is a pointer retrieved from a continuation, whose original
+ target was on the stack, and OFFSET is the appropriate offset from
+ the original stack to the continuation, then RELOC_MUMBLE (PTR,
+ OFFSET) is a pointer to the copy in the continuation of the
+ original referent, cast to an scm_debug_MUMBLE *. */
+#define RELOC_INFO(ptr, offset) \
+ ((scm_t_debug_info *) ((SCM_STACKITEM *) (ptr) + (offset)))
+#define RELOC_FRAME(ptr, offset) \
+ ((scm_t_debug_frame *) ((SCM_STACKITEM *) (ptr) + (offset)))
+
+
+/* Count number of debug info frames on a stack, beginning with
+ * DFRAME. OFFSET is used for relocation of pointers when the stack
+ * is read from a continuation.
+ */
+static scm_t_bits
+stack_depth (scm_t_debug_frame *dframe, scm_t_ptrdiff offset,
+ SCM *id, int *maxp)
+{
+ long n;
+ long max_depth = SCM_BACKTRACE_MAXDEPTH;
+ for (n = 0;
+ dframe && !SCM_VOIDFRAMEP (*dframe) && n < max_depth;
+ dframe = RELOC_FRAME (dframe->prev, offset))
+ {
+ if (SCM_EVALFRAMEP (*dframe))
+ {
+ scm_t_debug_info *info = RELOC_INFO (dframe->info, offset);
+ scm_t_debug_info *vect = RELOC_INFO (dframe->vect, offset);
+ n += (info - vect) / 2 + 1;
+ /* Data in the apply part of an eval info frame comes from previous
+ stack frame if the scm_t_debug_info vector is overflowed. */
+ if ((((info - vect) & 1) == 0)
+ && SCM_OVERFLOWP (*dframe)
+ && !SCM_UNBNDP (info[1].a.proc))
+ ++n;
+ }
+ else
+ ++n;
+ }
+ if (dframe && SCM_VOIDFRAMEP (*dframe))
+ *id = RELOC_INFO(dframe->vect, offset)[0].id;
+ else if (dframe)
+ *maxp = 1;
+ return n;
+}
+
+/* Read debug info from DFRAME into IFRAME.
+ */
+static void
+read_frame (scm_t_debug_frame *dframe, scm_t_ptrdiff offset,
+ scm_t_info_frame *iframe)
+{
+ scm_t_bits flags = SCM_UNPACK (SCM_INUM0); /* UGh. */
+ if (SCM_EVALFRAMEP (*dframe))
+ {
+ scm_t_debug_info *info = RELOC_INFO (dframe->info, offset);
+ scm_t_debug_info *vect = RELOC_INFO (dframe->vect, offset);
+ if ((info - vect) & 1)
+ {
+ /* Debug.vect ends with apply info. */
+ --info;
+ if (!SCM_UNBNDP (info[1].a.proc))
+ {
+ flags |= SCM_FRAMEF_PROC;
+ iframe->proc = info[1].a.proc;
+ iframe->args = info[1].a.args;
+ if (!SCM_ARGS_READY_P (*dframe))
+ flags |= SCM_FRAMEF_EVAL_ARGS;
+ }
+ }
+ iframe->source = scm_make_memoized (info[0].e.exp, info[0].e.env);
+ }
+ else
+ {
+ scm_t_debug_info *vect = RELOC_INFO (dframe->vect, offset);
+ flags |= SCM_FRAMEF_PROC;
+ iframe->proc = vect[0].a.proc;
+ iframe->args = vect[0].a.args;
+ }
+ iframe->flags = flags;
+}
+
+/* Look up the first body form of the apply closure. We'll use this
+ below to prevent it from being displayed.
+*/
+static SCM
+get_applybody ()
+{
+ SCM var = scm_sym2var (scm_sym_apply, SCM_BOOL_F, SCM_BOOL_F);
+ if (SCM_VARIABLEP (var) && SCM_CLOSUREP (SCM_VARIABLE_REF (var)))
+ return SCM_CAR (SCM_CLOSURE_BODY (SCM_VARIABLE_REF (var)));
+ else
+ return SCM_UNDEFINED;
+}
+
+#define NEXT_FRAME(iframe, n, quit) \
+do { \
+ if (SCM_MEMOIZEDP (iframe->source) \
+ && scm_is_eq (SCM_MEMOIZED_EXP (iframe->source), applybody)) \
+ { \
+ iframe->source = SCM_BOOL_F; \
+ if (scm_is_false (iframe->proc)) \
+ { \
+ --iframe; \
+ ++n; \
+ } \
+ } \
+ ++iframe; \
+ if (--n == 0) \
+ goto quit; \
+} while (0)
+
+
+/* Fill the scm_t_info_frame vector IFRAME with data from N stack frames
+ * starting with the first stack frame represented by debug frame
+ * DFRAME.
+ */
+
+static scm_t_bits
+read_frames (scm_t_debug_frame *dframe, scm_t_ptrdiff offset,
+ long n, scm_t_info_frame *iframes)
+{
+ scm_t_info_frame *iframe = iframes;
+ scm_t_debug_info *info, *vect;
+ static SCM applybody = SCM_UNDEFINED;
+
+ /* The value of applybody has to be setup after r4rs.scm has executed. */
+ if (SCM_UNBNDP (applybody))
+ applybody = get_applybody ();
+ for (;
+ dframe && !SCM_VOIDFRAMEP (*dframe) && n > 0;
+ dframe = RELOC_FRAME (dframe->prev, offset))
+ {
+ read_frame (dframe, offset, iframe);
+ if (SCM_EVALFRAMEP (*dframe))
+ {
+ /* If current frame is a macro during expansion, we should
+ skip the previously recorded macro transformer
+ application frame. */
+ if (SCM_MACROEXPP (*dframe) && iframe > iframes)
+ {
+ *(iframe - 1) = *iframe;
+ --iframe;
+ }
+ info = RELOC_INFO (dframe->info, offset);
+ vect = RELOC_INFO (dframe->vect, offset);
+ if ((info - vect) & 1)
+ --info;
+ /* Data in the apply part of an eval info frame comes from
+ previous stack frame if the scm_t_debug_info vector is
+ overflowed. */
+ else if (SCM_OVERFLOWP (*dframe)
+ && !SCM_UNBNDP (info[1].a.proc))
+ {
+ NEXT_FRAME (iframe, n, quit);
+ iframe->flags = SCM_UNPACK(SCM_INUM0) | SCM_FRAMEF_PROC;
+ iframe->proc = info[1].a.proc;
+ iframe->args = info[1].a.args;
+ }
+ if (SCM_OVERFLOWP (*dframe))
+ iframe->flags |= SCM_FRAMEF_OVERFLOW;
+ info -= 2;
+ NEXT_FRAME (iframe, n, quit);
+ while (info >= vect)
+ {
+ if (!SCM_UNBNDP (info[1].a.proc))
+ {
+ iframe->flags = SCM_UNPACK(SCM_INUM0) | SCM_FRAMEF_PROC;
+ iframe->proc = info[1].a.proc;
+ iframe->args = info[1].a.args;
+ }
+ else
+ iframe->flags = SCM_UNPACK (SCM_INUM0);
+ iframe->source = scm_make_memoized (info[0].e.exp,
+ info[0].e.env);
+ info -= 2;
+ NEXT_FRAME (iframe, n, quit);
+ }
+ }
+ else if (scm_is_eq (iframe->proc, scm_f_gsubr_apply))
+ /* Skip gsubr apply frames. */
+ continue;
+ else
+ {
+ NEXT_FRAME (iframe, n, quit);
+ }
+ quit:
+ if (iframe > iframes)
+ (iframe - 1) -> flags |= SCM_FRAMEF_REAL;
+ }
+ return iframe - iframes; /* Number of frames actually read */
+}
+
+/* Narrow STACK by cutting away stackframes (mutatingly).
+ *
+ * Inner frames (most recent) are cut by advancing the frames pointer.
+ * Outer frames are cut by decreasing the recorded length.
+ *
+ * Cut maximally INNER inner frames and OUTER outer frames using
+ * the keys INNER_KEY and OUTER_KEY.
+ *
+ * Frames are cut away starting at the end points and moving towards
+ * the center of the stack. The key is normally compared to the
+ * operator in application frames. Frames up to and including the key
+ * are cut.
+ *
+ * If INNER_KEY is #t a different scheme is used for inner frames:
+ *
+ * Frames up to but excluding the first source frame originating from
+ * a user module are cut, except for possible application frames
+ * between the user frame and the last system frame previously
+ * encountered.
+ */
+
+static void
+narrow_stack (SCM stack, long inner, SCM inner_key, long outer, SCM outer_key)
+{
+ scm_t_stack *s = SCM_STACK (stack);
+ unsigned long int i;
+ long n = s->length;
+
+ /* Cut inner part. */
+ if (scm_is_eq (inner_key, SCM_BOOL_T))
+ {
+ /* Cut all frames up to user module code */
+ for (i = 0; inner; ++i, --inner)
+ {
+ SCM m = s->frames[i].source;
+ if (SCM_MEMOIZEDP (m)
+ && !SCM_IMP (SCM_MEMOIZED_ENV (m))
+ && scm_is_false (scm_system_module_env_p (SCM_MEMOIZED_ENV (m))))
+ {
+ /* Back up in order to include any non-source frames */
+ while (i > 0)
+ {
+ m = s->frames[i - 1].source;
+ if (SCM_MEMOIZEDP (m))
+ break;
+
+ m = s->frames[i - 1].proc;
+ if (scm_is_true (scm_procedure_p (m))
+ && scm_is_true (scm_procedure_property
+ (m, scm_sym_system_procedure)))
+ break;
+
+ --i;
+ ++inner;
+ }
+ break;
+ }
+ }
+ }
+ else
+ /* Use standard cutting procedure. */
+ {
+ for (i = 0; inner; --inner)
+ if (scm_is_eq (s->frames[i++].proc, inner_key))
+ break;
+ }
+ s->frames = &s->frames[i];
+ n -= i;
+
+ /* Cut outer part. */
+ for (; n && outer; --outer)
+ if (scm_is_eq (s->frames[--n].proc, outer_key))
+ break;
+
+ s->length = n;
+}
+
+\f
+
+/* Stacks
+ */
+
+SCM scm_stack_type;
+
+SCM_DEFINE (scm_stack_p, "stack?", 1, 0, 0,
+ (SCM obj),
+ "Return @code{#t} if @var{obj} is a calling stack.")
+#define FUNC_NAME s_scm_stack_p
+{
+ return scm_from_bool(SCM_STACKP (obj));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_make_stack, "make-stack", 1, 0, 1,
+ (SCM obj, SCM args),
+ "Create a new stack. If @var{obj} is @code{#t}, the current\n"
+ "evaluation stack is used for creating the stack frames,\n"
+ "otherwise the frames are taken from @var{obj} (which must be\n"
+ "either a debug object or a continuation).\n\n"
+ "@var{args} should be a list containing any combination of\n"
+ "integer, procedure and @code{#t} values.\n\n"
+ "These values specify various ways of cutting away uninteresting\n"
+ "stack frames from the top and bottom of the stack that\n"
+ "@code{make-stack} returns. They come in pairs like this:\n"
+ "@code{(@var{inner_cut_1} @var{outer_cut_1} @var{inner_cut_2}\n"
+ "@var{outer_cut_2} @dots{})}.\n\n"
+ "Each @var{inner_cut_N} can be @code{#t}, an integer, or a\n"
+ "procedure. @code{#t} means to cut away all frames up to but\n"
+ "excluding the first user module frame. An integer means to cut\n"
+ "away exactly that number of frames. A procedure means to cut\n"
+ "away all frames up to but excluding the application frame whose\n"
+ "procedure matches the specified one.\n\n"
+ "Each @var{outer_cut_N} can be an integer or a procedure. An\n"
+ "integer means to cut away that number of frames. A procedure\n"
+ "means to cut away frames down to but excluding the application\n"
+ "frame whose procedure matches the specified one.\n\n"
+ "If the @var{outer_cut_N} of the last pair is missing, it is\n"
+ "taken as 0.")
+#define FUNC_NAME s_scm_make_stack
+{
+ long n, size;
+ int maxp;
+ scm_t_debug_frame *dframe;
+ scm_t_info_frame *iframe;
+ long offset = 0;
+ SCM stack, id;
+ SCM inner_cut, outer_cut;
+
+ /* Extract a pointer to the innermost frame of whatever object
+ scm_make_stack was given. */
+ if (scm_is_eq (obj, SCM_BOOL_T))
+ {
+ dframe = scm_i_last_debug_frame ();
+ }
+ else if (SCM_DEBUGOBJP (obj))
+ {
+ dframe = SCM_DEBUGOBJ_FRAME (obj);
+ }
+ else if (SCM_CONTINUATIONP (obj))
+ {
+ scm_t_contregs *cont = SCM_CONTREGS (obj);
+ offset = cont->offset;
+ dframe = RELOC_FRAME (cont->dframe, offset);
+ }
+ else
+ {
+ SCM_WRONG_TYPE_ARG (SCM_ARG1, obj);
+ /* not reached */
+ }
+
+ /* Count number of frames. Also get stack id tag and check whether
+ there are more stackframes than we want to record
+ (SCM_BACKTRACE_MAXDEPTH). */
+ id = SCM_BOOL_F;
+ maxp = 0;
+ n = stack_depth (dframe, offset, &id, &maxp);
+ size = n * SCM_FRAME_N_SLOTS;
+
+ /* Make the stack object. */
+ stack = scm_make_struct (scm_stack_type, scm_from_long (size), SCM_EOL);
+ SCM_STACK (stack) -> id = id;
+ iframe = &SCM_STACK (stack) -> tail[0];
+ SCM_STACK (stack) -> frames = iframe;
+
+ /* Translate the current chain of stack frames into debugging information. */
+ n = read_frames (dframe, offset, n, iframe);
+ SCM_STACK (stack) -> length = n;
+
+ /* Narrow the stack according to the arguments given to scm_make_stack. */
+ SCM_VALIDATE_REST_ARGUMENT (args);
+ while (n > 0 && !scm_is_null (args))
+ {
+ inner_cut = SCM_CAR (args);
+ args = SCM_CDR (args);
+ if (scm_is_null (args))
+ {
+ outer_cut = SCM_INUM0;
+ }
+ else
+ {
+ outer_cut = SCM_CAR (args);
+ args = SCM_CDR (args);
+ }
+
+ narrow_stack (stack,
+ scm_is_integer (inner_cut) ? scm_to_int (inner_cut) : n,
+ scm_is_integer (inner_cut) ? 0 : inner_cut,
+ scm_is_integer (outer_cut) ? scm_to_int (outer_cut) : n,
+ scm_is_integer (outer_cut) ? 0 : outer_cut);
+
+ n = SCM_STACK (stack) -> length;
+ }
+
+ if (n > 0)
+ {
+ if (maxp)
+ iframe[n - 1].flags |= SCM_FRAMEF_OVERFLOW;
+ return stack;
+ }
+ else
+ return SCM_BOOL_F;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_stack_id, "stack-id", 1, 0, 0,
+ (SCM stack),
+ "Return the identifier given to @var{stack} by @code{start-stack}.")
+#define FUNC_NAME s_scm_stack_id
+{
+ scm_t_debug_frame *dframe;
+ long offset = 0;
+ if (scm_is_eq (stack, SCM_BOOL_T))
+ {
+ dframe = scm_i_last_debug_frame ();
+ }
+ else if (SCM_DEBUGOBJP (stack))
+ {
+ dframe = SCM_DEBUGOBJ_FRAME (stack);
+ }
+ else if (SCM_CONTINUATIONP (stack))
+ {
+ scm_t_contregs *cont = SCM_CONTREGS (stack);
+ offset = cont->offset;
+ dframe = RELOC_FRAME (cont->dframe, offset);
+ }
+ else if (SCM_STACKP (stack))
+ {
+ return SCM_STACK (stack) -> id;
+ }
+ else
+ {
+ SCM_WRONG_TYPE_ARG (1, stack);
+ }
+
+ while (dframe && !SCM_VOIDFRAMEP (*dframe))
+ dframe = RELOC_FRAME (dframe->prev, offset);
+ if (dframe && SCM_VOIDFRAMEP (*dframe))
+ return RELOC_INFO (dframe->vect, offset)[0].id;
+ return SCM_BOOL_F;
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_stack_ref, "stack-ref", 2, 0, 0,
+ (SCM stack, SCM index),
+ "Return the @var{index}'th frame from @var{stack}.")
+#define FUNC_NAME s_scm_stack_ref
+{
+ unsigned long int c_index;
+
+ SCM_VALIDATE_STACK (1, stack);
+ c_index = scm_to_unsigned_integer (index, 0, SCM_STACK_LENGTH(stack)-1);
+ return scm_cons (stack, index);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_stack_length, "stack-length", 1, 0, 0,
+ (SCM stack),
+ "Return the length of @var{stack}.")
+#define FUNC_NAME s_scm_stack_length
+{
+ SCM_VALIDATE_STACK (1, stack);
+ return scm_from_int (SCM_STACK_LENGTH (stack));
+}
+#undef FUNC_NAME
+
+/* Frames
+ */
+
+SCM_DEFINE (scm_frame_p, "frame?", 1, 0, 0,
+ (SCM obj),
+ "Return @code{#t} if @var{obj} is a stack frame.")
+#define FUNC_NAME s_scm_frame_p
+{
+ return scm_from_bool(SCM_FRAMEP (obj));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_last_stack_frame, "last-stack-frame", 1, 0, 0,
+ (SCM obj),
+ "Return a stack which consists of a single frame, which is the\n"
+ "last stack frame for @var{obj}. @var{obj} must be either a\n"
+ "debug object or a continuation.")
+#define FUNC_NAME s_scm_last_stack_frame
+{
+ scm_t_debug_frame *dframe;
+ long offset = 0;
+ SCM stack;
+
+ if (SCM_DEBUGOBJP (obj))
+ {
+ dframe = SCM_DEBUGOBJ_FRAME (obj);
+ }
+ else if (SCM_CONTINUATIONP (obj))
+ {
+ scm_t_contregs *cont = SCM_CONTREGS (obj);
+ offset = cont->offset;
+ dframe = RELOC_FRAME (cont->dframe, offset);
+ }
+ else
+ {
+ SCM_WRONG_TYPE_ARG (1, obj);
+ /* not reached */
+ }
+
+ if (!dframe || SCM_VOIDFRAMEP (*dframe))
+ return SCM_BOOL_F;
+
+ stack = scm_make_struct (scm_stack_type, scm_from_int (SCM_FRAME_N_SLOTS),
+ SCM_EOL);
+ SCM_STACK (stack) -> length = 1;
+ SCM_STACK (stack) -> frames = &SCM_STACK (stack) -> tail[0];
+ read_frame (dframe, offset,
+ (scm_t_info_frame *) &SCM_STACK (stack) -> frames[0]);
+
+ return scm_cons (stack, SCM_INUM0);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_frame_number, "frame-number", 1, 0, 0,
+ (SCM frame),
+ "Return the frame number of @var{frame}.")
+#define FUNC_NAME s_scm_frame_number
+{
+ SCM_VALIDATE_FRAME (1, frame);
+ return scm_from_int (SCM_FRAME_NUMBER (frame));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_frame_source, "frame-source", 1, 0, 0,
+ (SCM frame),
+ "Return the source of @var{frame}.")
+#define FUNC_NAME s_scm_frame_source
+{
+ SCM_VALIDATE_FRAME (1, frame);
+ return SCM_FRAME_SOURCE (frame);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_frame_procedure, "frame-procedure", 1, 0, 0,
+ (SCM frame),
+ "Return the procedure for @var{frame}, or @code{#f} if no\n"
+ "procedure is associated with @var{frame}.")
+#define FUNC_NAME s_scm_frame_procedure
+{
+ SCM_VALIDATE_FRAME (1, frame);
+ return (SCM_FRAME_PROC_P (frame)
+ ? SCM_FRAME_PROC (frame)
+ : SCM_BOOL_F);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_frame_arguments, "frame-arguments", 1, 0, 0,
+ (SCM frame),
+ "Return the arguments of @var{frame}.")
+#define FUNC_NAME s_scm_frame_arguments
+{
+ SCM_VALIDATE_FRAME (1, frame);
+ return SCM_FRAME_ARGS (frame);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_frame_previous, "frame-previous", 1, 0, 0,
+ (SCM frame),
+ "Return the previous frame of @var{frame}, or @code{#f} if\n"
+ "@var{frame} is the first frame in its stack.")
+#define FUNC_NAME s_scm_frame_previous
+{
+ unsigned long int n;
+ SCM_VALIDATE_FRAME (1, frame);
+ n = scm_to_ulong (SCM_CDR (frame)) + 1;
+ if (n >= SCM_STACK_LENGTH (SCM_CAR (frame)))
+ return SCM_BOOL_F;
+ else
+ return scm_cons (SCM_CAR (frame), scm_from_ulong (n));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_frame_next, "frame-next", 1, 0, 0,
+ (SCM frame),
+ "Return the next frame of @var{frame}, or @code{#f} if\n"
+ "@var{frame} is the last frame in its stack.")
+#define FUNC_NAME s_scm_frame_next
+{
+ unsigned long int n;
+ SCM_VALIDATE_FRAME (1, frame);
+ n = scm_to_ulong (SCM_CDR (frame));
+ if (n == 0)
+ return SCM_BOOL_F;
+ else
+ return scm_cons (SCM_CAR (frame), scm_from_ulong (n - 1));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_frame_real_p, "frame-real?", 1, 0, 0,
+ (SCM frame),
+ "Return @code{#t} if @var{frame} is a real frame.")
+#define FUNC_NAME s_scm_frame_real_p
+{
+ SCM_VALIDATE_FRAME (1, frame);
+ return scm_from_bool(SCM_FRAME_REAL_P (frame));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_frame_procedure_p, "frame-procedure?", 1, 0, 0,
+ (SCM frame),
+ "Return @code{#t} if a procedure is associated with @var{frame}.")
+#define FUNC_NAME s_scm_frame_procedure_p
+{
+ SCM_VALIDATE_FRAME (1, frame);
+ return scm_from_bool(SCM_FRAME_PROC_P (frame));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_frame_evaluating_args_p, "frame-evaluating-args?", 1, 0, 0,
+ (SCM frame),
+ "Return @code{#t} if @var{frame} contains evaluated arguments.")
+#define FUNC_NAME s_scm_frame_evaluating_args_p
+{
+ SCM_VALIDATE_FRAME (1, frame);
+ return scm_from_bool(SCM_FRAME_EVAL_ARGS_P (frame));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_frame_overflow_p, "frame-overflow?", 1, 0, 0,
+ (SCM frame),
+ "Return @code{#t} if @var{frame} is an overflow frame.")
+#define FUNC_NAME s_scm_frame_overflow_p
+{
+ SCM_VALIDATE_FRAME (1, frame);
+ return scm_from_bool(SCM_FRAME_OVERFLOW_P (frame));
+}
+#undef FUNC_NAME
+
+\f
+
+void
+scm_init_stacks ()
+{
+ scm_stack_type =
+ scm_permanent_object
+ (scm_make_vtable (scm_from_locale_string (SCM_STACK_LAYOUT),
+ SCM_UNDEFINED));
+ scm_set_struct_vtable_name_x (scm_stack_type,
+ scm_from_locale_symbol ("stack"));
+#include "libguile/stacks.x"
+}
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/