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    Length: 4207 (0x106f)
    Types: TextFile
    Names: »bkpt.c«

└─⟦a0efdde77⟧ Bits:30001252 EUUGD11 Tape, 1987 Spring Conference Helsinki
    └─ ⟦this⟧ »EUUGD11/gnu-31mar87/scheme/microcode/bkpt.c« 

TextFile

/*	Emacs -*-C-*-an't tell the language			*/

/****************************************************************
*                                                               *
*                         Copyright (c) 1986                    *
*               Massachusetts Institute of Technology           *
*                                                               *
* This material was developed by the Scheme project at the      *
* Massachusetts Institute of Technology, Department of          *
* Electrical Engineering and Computer Science.  Permission to   *
* copy this software, to redistribute it, and to use it for any *
* purpose is granted, subject to the following restrictions and *
* understandings.                                               *
*                                                               *
* 1. Any copy made of this software must include this copyright *
* notice in full.                                               *
*                                                               *
* 2. Users of this software agree to make their best efforts (a)*
* to return to the MIT Scheme project any improvements or       *
* extensions that they make, so that these may be included in   *
* future releases; and (b) to inform MIT of noteworthy uses of  *
* this software.                                                *
*                                                               *
* 3.  All materials developed as a consequence of the use of    *
* this software shall duly acknowledge such use, in accordance  *
* with the usual standards of acknowledging credit in academic  *
* research.                                                     *
*                                                               *
* 4. MIT has made no warrantee or representation that the       *
* operation of this software will be error-free, and MIT is     *
* under no obligation to provide any services, by way of        *
* maintenance, update, or otherwise.                            *
*                                                               *
* 5.  In conjunction with products arising from the use of this *
* material, there shall be no use of the name of the            *
* Massachusetts Institute of Technology nor of any adaptation   *
* thereof in any advertising, promotional, or sales literature  *
* without prior written consent from MIT in each case.          *
*                                                               *
****************************************************************/

/* File: BKPT.C
 *
 * This file contains breakpoint utilities.
 * Disabled when not debugging the interpreter.
 *
 */
\f


#include "scheme.h"

#ifndef ENABLE_DEBUGGING_TOOLS
#include "Error: Not debugging but bkpt.c included"
#endif

sp_record_list SP_List = sp_nil;

extern Boolean Add_a_Pop_Return_Breakpoint();

static struct sp_record One_Before =
{ ((Pointer *) 0),
  sp_nil 	
};

Boolean Add_a_Pop_Return_Breakpoint(SP)
Pointer *SP;
{ sp_record_list old = SP_List;
  SP_List = ((sp_record_list) malloc(sizeof(struct sp_record)));
  if (SP_List == sp_nil)
  { fprintf(stderr, "Could not allocate a breakpoint structure\n");
    SP_List = old;
    return false;
  }
  SP_List->sp = SP;
  SP_List->next = old;
  One_Before.next = SP_List;
  return true;
}

/* This uses register rather than fast because it is invoked
 * very often and would make things too slow.
 */

void Pop_Return_Break_Point()
{ register Pointer *SP = Stack_Pointer;
  register sp_record_list previous = &One_Before;
  register sp_record_list this = previous->next; /* = SP_List */
  for ( ;
       this != sp_nil;
       previous = this, this = this->next)
    if (this->sp == SP)
    { Handle_Pop_Return_Break();
      previous->next = this->next;
      break;
    }
  SP_List = One_Before.next;
  return;
}

/* A breakpoint can be placed here from a C debugger to examine 
   the state of the world. */

extern Boolean Print_One_Continuation_Frame();

Handle_Pop_Return_Break()
{ Boolean ignore;
  Pointer *Old_Stack = Stack_Pointer;

  printf("Pop Return Break: SP = 0x%x\n", Stack_Pointer);
  ignore = Print_One_Continuation_Frame();
  Stack_Pointer = Old_Stack;
  return;
}