1 /* Copyright (c) 1979 Regents of the University of California */ 2 3 /* static char sccsid[] = "@(#)vars.h 1.2 01/10/81"; */ 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; /* 1 => no post mortum dump */ 197 extern long _mode; /* execl by PX, PIPE, or PIX */ 198 extern long _stlim; /* statement limit */ 199 extern long _stcnt; /* statement count */ 200 extern char *_maxptr; /* maximum valid pointer */ 201 extern char *_minptr; /* minimum valid pointer */ 202 extern long *_pcpcount; /* pointer to pxp buffer */ 203 extern long _cntrs; /* number of counters */ 204 extern long _rtns; /* number of routine cntrs */ 205 206 /* 207 * The file i/o routines maintain a notion of a "current file". 208 * A pointer to this file structure is kept in "curfile". 209 * 210 * file structures 211 */ 212 struct iorechd { 213 char *fileptr; /* ptr to file window */ 214 long lcount; /* number of lines printed */ 215 long llimit; /* maximum number of text lines */ 216 FILE *fbuf; /* FILE ptr */ 217 struct iorec *fchain; /* chain to next file */ 218 struct iorec *flev; /* ptr to associated file variable */ 219 char *pfname; /* ptr to name of file */ 220 short funit; /* file status flags */ 221 short fblk; /* index into active file table */ 222 long fsize; /* size of elements in the file */ 223 char fname[NAMSIZ]; /* name of associated UNIX file */ 224 }; 225 226 struct iorec { 227 char *fileptr; /* ptr to file window */ 228 long lcount; /* number of lines printed */ 229 long llimit; /* maximum number of text lines */ 230 FILE *fbuf; /* FILE ptr */ 231 struct iorec *fchain; /* chain to next file */ 232 struct iorec *flev; /* ptr to associated file variable */ 233 char *pfname; /* ptr to name of file */ 234 short funit; /* file status flags */ 235 short fblk; /* index into active file table */ 236 long fsize; /* size of elements in the file */ 237 char fname[NAMSIZ]; /* name of associated UNIX file */ 238 char buf[BUFSIZ]; /* I/O buffer */ 239 char window[1]; /* file window element */ 240 }; 241 242 /* 243 * unit flags 244 */ 245 #define FDEF 0x80 /* 1 => reserved file name */ 246 #define FTEXT 0x40 /* 1 => text file, process EOLN */ 247 #define FWRITE 0x20 /* 1 => open for writing */ 248 #define FREAD 0x10 /* 1 => open for reading */ 249 #define TEMP 0x08 /* 1 => temporary file */ 250 #define SYNC 0x04 /* 1 => window is out of sync */ 251 #define EOLN 0x02 /* 1 => at end of line */ 252 #define EOFF 0x01 /* 1 => at end of file */ 253 254 /* 255 * file routines 256 */ 257 extern struct iorec *GETNAME(); 258 extern char *MKTEMP(); 259 260 /* 261 * file record variables 262 */ 263 extern struct iorechd _fchain; /* head of active file chain */ 264 extern struct iorec *_actfile[]; /* table of active files */ 265 extern long _filefre; /* last used entry in _actfile */ 266 267 /* 268 * standard files 269 */ 270 extern struct iorechd input; 271 extern struct iorechd output; 272 extern struct iorechd _err; 273 274 /* 275 * Px execution profile array 276 */ 277 #ifdef PROFILE 278 #define NUMOPS 256 279 extern long _profcnts[NUMOPS]; 280 #endif PROFILE 281