projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| f70ab843 RH |
1 | /* |
| 2 | * Copyright (c) 1982 Regents of the University of California | |
| 825ccb47 | 3 | * @(#)asexpr.h 4.4 %G% |
| f70ab843 | 4 | */ |
| ac675cfd BJ |
5 | /* |
| 6 | * Definitions to parse tokens | |
| 7 | */ | |
| 8 | ||
| 9 | #define ERROR(string) yyerror(string); goto errorfix | |
| 10 | ||
| 11 | #define peekahead (*tokptr) | |
| 12 | ||
| 13 | #define shift val = yylex() | |
| 14 | #define advance shift | |
| 15 | ||
| 16 | #define shiftover(token) if (val != token) { \ | |
| 825ccb47 | 17 | shiftoerror(token); \ |
| ac675cfd BJ |
18 | goto errorfix; \ |
| 19 | } \ | |
| 20 | shift | |
| 21 | ||
| 22 | #define advanceover shiftover | |
| 23 | ||
| 24 | /* | |
| 25 | * To speed up the expression processing, we class the input tokens | |
| 26 | * into various sets. | |
| 27 | * | |
| 28 | * We don't call the recursive descent expression analyzer if we can | |
| 29 | * determine by looking at the next token after the first token in | |
| 30 | * an expression that the expression is simple (name, integer or floating | |
| 31 | * point value). Expressions with operators are parsed using the recursive | |
| 32 | * descent method. | |
| 33 | */ | |
| 34 | ||
| 35 | /* | |
| 36 | * Functional forwards for expression utility routines | |
| 37 | */ | |
| 38 | struct exp *combine(); | |
| 39 | struct exp *boolterm(); | |
| 40 | struct exp *term(); | |
| 41 | struct exp *factor(); | |
| 42 | struct exp *yukkyexpr(); | |
| 43 | ||
| 44 | /* | |
| 45 | * The set definitions | |
| 46 | */ | |
| 47 | ||
| 48 | extern char tokensets[(LASTTOKEN) - (FIRSTTOKEN) + 1]; | |
| 49 | ||
| 451260e7 | 50 | #define LINSTBEGIN 01 /*SEMI, NL, NAME*/ |
| ac675cfd | 51 | #define EBEGOPS 02 /*LP, MINUS, TILDE*/ |
| 451260e7 | 52 | #define YUKKYEXPRBEG 04 /*NAME, INSTn, INST0, REG, BFINT*/ |
| ac675cfd | 53 | #define SAFEEXPRBEG 010 /*INT, FLTNUM*/ |
| 451260e7 | 54 | #define ADDOPS 020 /*PLUS, MINUS*/ |
| ac675cfd | 55 | #define BOOLOPS 040 /*IOR, XOR, AND*/ |
| 451260e7 | 56 | #define MULOPS 0100 /*LSH, RSH, MUL, DIV, TILDE*/ |
| ac675cfd BJ |
57 | |
| 58 | #define INTOKSET(val, set) (tokensets[(val)] & (set) ) | |
| 59 | ||
| f70ab843 RH |
60 | inttoktype exprparse(); |
| 61 | inttoktype funnyreg(); | |
| 62 | inttoktype yylex(); | |
| 63 | ||
| ac675cfd BJ |
64 | #define expr(xp, val) { \ |
| 65 | if ( (!INTOKSET(val, EBEGOPS)) && (!INTOKSET(peekahead, ADDOPS+BOOLOPS+MULOPS))) { \ | |
| 66 | if (INTOKSET(val, YUKKYEXPRBEG)) xp = yukkyexpr(val, yylval); \ | |
| 67 | else xp = (struct exp *) yylval; \ | |
| 68 | shift; \ | |
| 69 | } else { \ | |
| 70 | val = exprparse(val, ptrloc1xp); \ | |
| 71 | xp = loc1xp; \ | |
| 72 | } \ | |
| 73 | } | |
| 74 | ||
| 75 | /* | |
| 76 | * Registers can be either of the form r0...pc, or | |
| 77 | * of the form % <expression> | |
| 78 | * NOTE: Reizers documentation on the assembler says that it | |
| 79 | * can be of the form r0 + <expression>.. That's not true. | |
| 80 | * | |
| 81 | * NOTE: Reizer's yacc grammar would seem to allow an expression | |
| 82 | * to be: (This is undocumented) | |
| 83 | * a) a register | |
| 84 | * b) an Instruction (INSTn or INST0) | |
| 85 | */ | |
| 86 | ||
| 87 | #define findreg(regno) \ | |
| 88 | if (val == REG) { \ | |
| 89 | regno = yylval; \ | |
| 90 | shift; \ | |
| 91 | } else \ | |
| 92 | if (val == REGOP) { \ | |
| 93 | shift; /*over the REGOP*/ \ | |
| 94 | val = funnyreg(val, ptrregno); \ | |
| 95 | } \ | |
| 96 | else { ERROR ("register expected"); } |