1 /* Copyright (c) 1979 Regents of the University of California */ 2 3 /* static char sccsid[] = "@(#)vars.h 1.3 01/16/81"; */ 4 5 #include <stdio.h> 6 7 /* 8 * px - Berkeley Pascal interpreter 9 * 10 * Version 4.0, January 1981 11 * 12 * Original version by Ken Thompson 13 * 14 * Substantial revisions by Bill Joy and Chuck Haley 15 * November-December 1976 16 * 17 * Rewritten for VAX 11/780 by Kirk McKusick 18 * Fall 1978 19 * 20 * Rewritten in ``C'' using libpc by Kirk McKusick 21 * Winter 1981 22 * 23 * Px is described in detail in the "PX 4.0 Implementation Notes" 24 * The source code for px is in several major pieces: 25 * 26 * int.c C main program which reads in interpreter code 27 * interp.c Driver including main interpreter loop and 28 * the interpreter instructions grouped by their 29 * positions in the interpreter table. 30 * except.c Handlers for interpreter specific errors not 31 * included in libpc. 32 * utilities.c Interpreter exit, backtrace, and runtime statistics. 33 * 34 * In addition there are several headers defining mappings for panic 35 * names into codes, and a definition of the interpreter transfer 36 * table. These are made by the script make.ed1 in this directory and 37 * the routine opc.c from ${PASCALDIR}. (see the makefile for details) 38 */ 39 #define PXPFILE "pmon.out" 40 #define BITSPERBYTE 8 41 #define BITSPERLONG (BITSPERBYTE * sizeof(long)) 42 #define HZ 60 43 #define TRUE 1 44 #define FALSE 0 45 #define MAXLVL 20 46 #define NAMSIZ 76 47 #define MAXFILES 32 48 #define PREDEF 2 49 #define STDLVL ((struct iorec *)(0x7ffffff1)) 50 #define GLVL ((struct iorec *)(0x7ffffff0)) 51 #define FILNIL ((struct iorec *)(0)) 52 #define INPUT ((struct iorec *)(&input)) 53 #define OUTPUT ((struct iorec *)(&output)) 54 #define ERR ((struct iorec *)(&_err)) 55 #define PX 0 /* normal run of px */ 56 #define PIX 1 /* load and go */ 57 #define PIPE 2 /* bootstrap via a pipe */ 58 #define releq 0 59 #define relne 2 60 #define rellt 4 61 #define relgt 6 62 #define relle 8 63 #define relge 10 64 65 /* 66 * interrupt and allocation routines 67 */ 68 extern long createtime; 69 extern char *PALLOC(); 70 extern char *malloc(); 71 extern intr(); 72 extern memsize(); 73 extern except(); 74 extern syserr(); 75 extern liberr(); 76 77 /* 78 * stack routines 79 */ 80 extern short pop2(); 81 extern long pop4(); 82 extern double pop8(); 83 extern char *pushsp(); 84 85 /* 86 * emulated pc types 87 */ 88 union progcntr { 89 char *cp; 90 unsigned char *ucp; 91 short *sp; 92 unsigned short *usp; 93 long *lp; 94 double *dp; 95 struct hdr *hdrp; 96 }; 97 98 /* 99 * THE RUNTIME DISPLAY 100 * 101 * The entries in the display point to the active static block marks. 102 * The first entry in the display is for the global variables, 103 * then the procedure or function at level one, etc. 104 * Each display entry points to a stack frame as shown: 105 * 106 * base of stack frame 107 * --------------- 108 * | | 109 * | block mark | 110 * | | 111 * --------------- <-- display entry "stp" points here 112 * | | <-- display entry "locvars" points here 113 * | local | 114 * | variables | 115 * | | 116 * --------------- 117 * | | 118 * | expression | 119 * | temporary | 120 * | storage | 121 * | | 122 * - - - - - - - - 123 * 124 * The information in the block mark is thus at positive offsets from 125 * the display.stp pointer entries while the local variables are at negative 126 * offsets from display.locvars. The block mark actually consists of 127 * two parts. The first part is created at CALL and the second at entry, 128 * i.e. BEGIN. Thus: 129 * 130 * ------------------------- 131 * | | 132 * | Saved lino | 133 * | Saved lc | 134 * | Saved dp | 135 * | | 136 * ------------------------- 137 * | | 138 * | Saved (dp) | 139 * | | 140 * | Pointer to current | 141 * | routine header info | 142 * | | 143 * | Saved value of | 144 * | "curfile" | 145 * | | 146 * | Empty tos value | 147 * | | 148 * ------------------------- 149 */ 150 151 /* 152 * runtime display structure 153 */ 154 struct disp { 155 char *locvars; /* pointer to local variables */ 156 struct stack *stp; /* pointer to local stack frame */ 157 }; 158 159 struct stack { 160 char *tos; /* pointer to top of stack frame */ 161 struct iorec *file; /* pointer to active file name */ 162 struct hdr { 163 long framesze; /* number of bytes of local vars */ 164 long nargs; /* number of bytes of arguments */ 165 short offset; /* offset of procedure in source file */ 166 char name[1]; /* name of active procedure */ 167 } *entry; 168 struct disp odisp; /* previous display value for this level */ 169 struct disp *dp; /* pointer to active display entry */ 170 union progcntr pc; /* previous location counter */ 171 long lino; /* previous line number */ 172 }; 173 174 union disply { 175 struct disp frame[MAXLVL]; 176 char *raw[2*MAXLVL]; 177 }; 178 179 /* 180 * formal routine structure 181 */ 182 struct formalrtn { 183 char *entryaddr; 184 long cbn; 185 struct disp disp[2*MAXLVL]; 186 }; 187 188 /* 189 * program variables 190 */ 191 extern union disply _display; /* runtime display */ 192 extern struct disp *_dp; /* ptr to active frame */ 193 extern long _lino; /* current line number */ 194 extern int _argc; /* number of passed args */ 195 extern char **_argv; /* values of passed args */ 196 extern long _nodump; /* TRUE => no post mortum dump */ 197 extern long _runtst; /* TRUE => runtime tests */ 198 extern long _mode; /* execl by PX, PIPE, or PIX */ 199 extern long _stlim; /* statement limit */ 200 extern long _stcnt; /* statement count */ 201 extern long _seed; /* random number seed */ 202 extern char *_maxptr; /* maximum valid pointer */ 203 extern char *_minptr; /* minimum valid pointer */ 204 extern long *_pcpcount; /* pointer to pxp buffer */ 205 extern long _cntrs; /* number of counters */ 206 extern long _rtns; /* number of routine cntrs */ 207 208 /* 209 * The file i/o routines maintain a notion of a "current file". 210 * A pointer to this file structure is kept in "curfile". 211 * 212 * file structures 213 */ 214 struct iorechd { 215 char *fileptr; /* ptr to file window */ 216 long lcount; /* number of lines printed */ 217 long llimit; /* maximum number of text lines */ 218 FILE *fbuf; /* FILE ptr */ 219 struct iorec *fchain; /* chain to next file */ 220 struct iorec *flev; /* ptr to associated file variable */ 221 char *pfname; /* ptr to name of file */ 222 short funit; /* file status flags */ 223 short fblk; /* index into active file table */ 224 long fsize; /* size of elements in the file */ 225 char fname[NAMSIZ]; /* name of associated UNIX file */ 226 }; 227 228 struct iorec { 229 char *fileptr; /* ptr to file window */ 230 long lcount; /* number of lines printed */ 231 long llimit; /* maximum number of text lines */ 232 FILE *fbuf; /* FILE ptr */ 233 struct iorec *fchain; /* chain to next file */ 234 struct iorec *flev; /* ptr to associated file variable */ 235 char *pfname; /* ptr to name of file */ 236 short funit; /* file status flags */ 237 short fblk; /* index into active file table */ 238 long fsize; /* size of elements in the file */ 239 char fname[NAMSIZ]; /* name of associated UNIX file */ 240 char buf[BUFSIZ]; /* I/O buffer */ 241 char window[1]; /* file window element */ 242 }; 243 244 /* 245 * unit flags 246 */ 247 #define FDEF 0x80 /* 1 => reserved file name */ 248 #define FTEXT 0x40 /* 1 => text file, process EOLN */ 249 #define FWRITE 0x20 /* 1 => open for writing */ 250 #define FREAD 0x10 /* 1 => open for reading */ 251 #define TEMP 0x08 /* 1 => temporary file */ 252 #define SYNC 0x04 /* 1 => window is out of sync */ 253 #define EOLN 0x02 /* 1 => at end of line */ 254 #define EOFF 0x01 /* 1 => at end of file */ 255 256 /* 257 * file routines 258 */ 259 extern struct iorec *GETNAME(); 260 extern char *MKTEMP(); 261 262 /* 263 * file record variables 264 */ 265 extern struct iorechd _fchain; /* head of active file chain */ 266 extern struct iorec *_actfile[]; /* table of active files */ 267 extern long _filefre; /* last used entry in _actfile */ 268 269 /* 270 * standard files 271 */ 272 extern struct iorechd input; 273 extern struct iorechd output; 274 extern struct iorechd _err; 275 276 /* 277 * Px execution profile array 278 */ 279 #ifdef PROFILE 280 #define NUMOPS 256 281 extern long _profcnts[NUMOPS]; 282 #endif PROFILE 283