BSD 4 release

[unix-history] / usr / src / cmd / px / h00vars.h

/* Copyright (c) 1979 Regents of the University of California */

/* static       char sccsid[] = "@(#)h00vars.h 4.1 10/10/80"; */

/*
* px - Berkeley Pascal interpreter
*
* Version 2.0, January 1979
*
* Original version by Ken Thompson
*
* Substantial revisions by Bill Joy and Chuck Haley
* November-December 1976
*
* Rewritten for VAX 11/780 by Kirk McKusick
* Fall 1978
*
* Px is described in detail in the "PX 1.0 Implementation Notes"
* The source code for px is in several major pieces:
*
*      int.c           C main program which reads in interpreter code
*      00case.s        Driver including main interpreter loop
*      dd*.s           Where dd are digits, interpreter instructions
*                      grouped by their positions in the interpreter table.
*      p*.c            Various C language routines supporting the system.
*
* In addition there are several headers defining mappings for error
* messages names into codes, and a definition of the interpreter transfer
* table. These are made by the script Emake in this directory and the scripts
* in the directory '../opcodes'.
*/
#define TRUE            1
#define FALSE           0
#define BITSPERLONG     32

long    argc;
char    **argv;

/*
* Pascal runtime errors transfer to the routine
* 'error' in the file perror.c to decode them.
*/
int     perrno;         /* number of error which occurred */

/*
* Definitions for memory allocation
* Memory allocation is done by palloc in utilities.c
*/

/*
* The file i/o routines maintain a notion of a "current file".
* The printing name of this file is kept in the variable
* "file" for use in error messages.
*/
char    *file;          /* ptr to active file name */
long    fchain;         /* head of active file chain */
\f
/*
* THE RUNTIME DISPLAY
*
* The entries in the display point to the active static block marks.
* The first entry in the display is for the global variables,
* then the procedure or function at level one, etc.
* Each display entry points to a stack frame as shown:
*
*              base of stack frame
*                ---------------
*                |             |
*                | block mark  |
*                |             |
*                ---------------  <-- display entry points here
*                |             |
*                |   local     |
*                |  variables  |
*                |             |
*                ---------------
*                |             |
*                |  expression |
*                |  temporary  |
*                |  storage    |
*                |             |
*                - - - - - - - -
*
* The information in the block mark is thus at positive offsets from
* the display pointer entries while the local variables are at negative
* offsets. The block mark actually consists of two parts. The first
* part is created at CALL and the second at entry, i.e. BEGIN. Thus:
*
*              -------------------------
*              |                       |
*              |  Saved lino           |
*              |  Saved lc             |
*              |  Saved dp             |
*              |                       |
*              -------------------------
*              |                       |
*              |  Saved (dp)           |
*              |                       |
*              |  Current section name |
*              |   and entry line ptr  |
*              |                       |
*              |  Saved file name and  |
*              |   file buffer ptr     |
*              |                       |
*              |  Empty tos value      |
*              |                       |
*              -------------------------
*/
\f
/*
* Structure for accessing things in the block mark
*/
struct stack {
       long    *tos;           /* pointer to top of stack frame */
       char    *file;          /* pointer to active file name */
       long    buf;            /* pointer to active file record */
       struct  {
               long    nargs;  /* number of bytes of arguments */
               short   offset; /* offset of procedure in source file */
               char    name[1];/* name of active procedure */
               } *entry;
       struct  stack *disp;    /* previous display value for this level */
       struct  stack **dp;     /* pointer to active display entry */
       long    lc;             /* previous location counter */
       long    lino;           /* previous line number */
       } *display[20];
\f
/*
* Program option variables
*/
long    stcnt;          /* number of statements executed */
long    stlim;          /* max number of statements to execute */
long    llimit;         /* max number of lines per text file */
short   nodump;         /* 1 => no post mortum dump */
short   mode;           /* mode of input to interpreter */
#define PX      0       /* normal run of px */
#define PIX     1       /* load and go */
#define PIPE    2       /* bootstrap via a pipe */
\f
/*
* Pxp variables
*/
char    *pxpbuf;        /* pointer to pxp buffer */
long    pxpsize;        /* size of pxp buffer */

#ifdef profile
/*
* Px execution profile data
*/
#define numops 256
struct cntrec {
       double  counts[numops]; /* instruction counts */
       long    runs;           /* number of interpreter runs */
       long    startdate;      /* date profile started */
       long    usrtime;        /* total user time consumed */
       long    systime;        /* total system time consumed */
       double  stmts;          /* number of pascal statements executed */
       } profdata;
long    profcnts[numops];
#define proffile        "/usr/grad/mckusick/px/profile/pcnt.out"
FILE    *datafile;              /* input datafiles */
#else
int     profcnts;       /* dummy just to keep the linker happy */
#endif