projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| f70ab843 | 1 | /* |
| bcf1365c DF |
2 | * Copyright (c) 1982 Regents of the University of California. |
| 3 | * All rights reserved. The Berkeley software License Agreement | |
| 4 | * specifies the terms and conditions for redistribution. | |
| 5 | * | |
| 6 | * @(#)asexpr.h 5.1 (Berkeley) %G% | |
| f70ab843 | 7 | */ |
| bcf1365c | 8 | |
| ac675cfd BJ |
9 | /* |
| 10 | * Definitions to parse tokens | |
| 11 | */ | |
| 12 | ||
| 13 | #define ERROR(string) yyerror(string); goto errorfix | |
| 14 | ||
| 15 | #define peekahead (*tokptr) | |
| 16 | ||
| 17 | #define shift val = yylex() | |
| 18 | #define advance shift | |
| 19 | ||
| 20 | #define shiftover(token) if (val != token) { \ | |
| 825ccb47 | 21 | shiftoerror(token); \ |
| ac675cfd BJ |
22 | goto errorfix; \ |
| 23 | } \ | |
| 24 | shift | |
| 25 | ||
| 26 | #define advanceover shiftover | |
| 27 | ||
| 28 | /* | |
| 29 | * To speed up the expression processing, we class the input tokens | |
| 30 | * into various sets. | |
| 31 | * | |
| 32 | * We don't call the recursive descent expression analyzer if we can | |
| 33 | * determine by looking at the next token after the first token in | |
| 34 | * an expression that the expression is simple (name, integer or floating | |
| 35 | * point value). Expressions with operators are parsed using the recursive | |
| 36 | * descent method. | |
| 37 | */ | |
| 38 | ||
| 39 | /* | |
| 40 | * Functional forwards for expression utility routines | |
| 41 | */ | |
| 42 | struct exp *combine(); | |
| 43 | struct exp *boolterm(); | |
| 44 | struct exp *term(); | |
| 45 | struct exp *factor(); | |
| 46 | struct exp *yukkyexpr(); | |
| 47 | ||
| 48 | /* | |
| 49 | * The set definitions | |
| 50 | */ | |
| 51 | ||
| 52 | extern char tokensets[(LASTTOKEN) - (FIRSTTOKEN) + 1]; | |
| 53 | ||
| 451260e7 | 54 | #define LINSTBEGIN 01 /*SEMI, NL, NAME*/ |
| ac675cfd | 55 | #define EBEGOPS 02 /*LP, MINUS, TILDE*/ |
| 451260e7 | 56 | #define YUKKYEXPRBEG 04 /*NAME, INSTn, INST0, REG, BFINT*/ |
| ac675cfd | 57 | #define SAFEEXPRBEG 010 /*INT, FLTNUM*/ |
| 451260e7 | 58 | #define ADDOPS 020 /*PLUS, MINUS*/ |
| ac675cfd | 59 | #define BOOLOPS 040 /*IOR, XOR, AND*/ |
| 451260e7 | 60 | #define MULOPS 0100 /*LSH, RSH, MUL, DIV, TILDE*/ |
| ac675cfd BJ |
61 | |
| 62 | #define INTOKSET(val, set) (tokensets[(val)] & (set) ) | |
| 63 | ||
| f70ab843 RH |
64 | inttoktype exprparse(); |
| 65 | inttoktype funnyreg(); | |
| 66 | inttoktype yylex(); | |
| 67 | ||
| ac675cfd BJ |
68 | #define expr(xp, val) { \ |
| 69 | if ( (!INTOKSET(val, EBEGOPS)) && (!INTOKSET(peekahead, ADDOPS+BOOLOPS+MULOPS))) { \ | |
| 70 | if (INTOKSET(val, YUKKYEXPRBEG)) xp = yukkyexpr(val, yylval); \ | |
| 71 | else xp = (struct exp *) yylval; \ | |
| 72 | shift; \ | |
| 73 | } else { \ | |
| 74 | val = exprparse(val, ptrloc1xp); \ | |
| 75 | xp = loc1xp; \ | |
| 76 | } \ | |
| 77 | } | |
| 78 | ||
| 79 | /* | |
| 80 | * Registers can be either of the form r0...pc, or | |
| 81 | * of the form % <expression> | |
| 82 | * NOTE: Reizers documentation on the assembler says that it | |
| 83 | * can be of the form r0 + <expression>.. That's not true. | |
| 84 | * | |
| 85 | * NOTE: Reizer's yacc grammar would seem to allow an expression | |
| 86 | * to be: (This is undocumented) | |
| 87 | * a) a register | |
| 88 | * b) an Instruction (INSTn or INST0) | |
| 89 | */ | |
| 90 | ||
| 91 | #define findreg(regno) \ | |
| 92 | if (val == REG) { \ | |
| 93 | regno = yylval; \ | |
| 94 | shift; \ | |
| 95 | } else \ | |
| 96 | if (val == REGOP) { \ | |
| 97 | shift; /*over the REGOP*/ \ | |
| 98 | val = funnyreg(val, ptrregno); \ | |
| 99 | } \ | |
| 100 | else { ERROR ("register expected"); } |