projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| cfa3372e CH |
1 | /* Copyright (c) 1979 Regents of the University of California */ |
| 2 | # | |
| 3 | /* | |
| 4 | * pi - Pascal interpreter code translator | |
| 5 | * | |
| 6 | * Charles Haley, Bill Joy UCB | |
| 7 | * Version 1.2 November 1978 | |
| 8 | */ | |
| 9 | ||
| 10 | #include "whoami" | |
| 11 | #include "0.h" | |
| 12 | #include "tree.h" | |
| 13 | #include "opcode.h" | |
| 14 | ||
| 15 | /* | |
| 16 | * Label enters the definitions | |
| 17 | * of the label declaration part | |
| 18 | * into the namelist. | |
| 19 | */ | |
| 20 | label(r, l) | |
| 21 | int *r, l; | |
| 22 | { | |
| 23 | #ifndef PI0 | |
| 24 | register *ll; | |
| 25 | register struct nl *p, *lp; | |
| 26 | ||
| 27 | lp = NIL; | |
| 28 | #else | |
| 29 | send(REVLAB, r); | |
| 30 | #endif | |
| 31 | line = l; | |
| 32 | #ifndef PI1 | |
| 33 | if (parts & (CPRT|TPRT|VPRT)) | |
| 34 | error("Label declarations must precede const, type and var declarations"); | |
| 35 | if (parts & LPRT) | |
| 36 | error("All labels must be declared in one label part"); | |
| 37 | parts |= LPRT; | |
| 38 | #endif | |
| 39 | #ifndef PI0 | |
| 40 | for (ll = r; ll != NIL; ll = ll[2]) { | |
| 41 | l = getlab(); | |
| 42 | p = enter(defnl(ll[1], LABEL, 0, l)); | |
| 43 | /* | |
| 44 | * Get the label for the eventual target | |
| 45 | */ | |
| 46 | p->value[1] = getlab(); | |
| 47 | p->chain = lp; | |
| 48 | p->nl_flags |= (NFORWD|NMOD); | |
| 49 | p->value[NL_GOLEV] = NOTYET; | |
| 50 | p->entloc = l; | |
| 51 | lp = p; | |
| 52 | /* | |
| 53 | * This operator is between | |
| 54 | * the bodies of two procedures | |
| 55 | * and provides a target for | |
| 56 | * gotos for this label via TRA. | |
| 57 | */ | |
| 58 | putlab(l); | |
| 59 | put2(O_GOTO | cbn<<9, p->value[1]); | |
| 60 | } | |
| 61 | gotos[cbn] = lp; | |
| 62 | # ifdef PTREE | |
| 63 | { | |
| 64 | pPointer Labels = LabelDCopy( r ); | |
| 65 | ||
| 66 | pDEF( PorFHeader[ nesting ] ).PorFLabels = Labels; | |
| 67 | } | |
| 68 | # endif | |
| 69 | #endif | |
| 70 | } | |
| 71 | ||
| 72 | #ifndef PI0 | |
| 73 | /* | |
| 74 | * Gotoop is called when | |
| 75 | * we get a statement "goto label" | |
| 76 | * and generates the needed tra. | |
| 77 | */ | |
| 78 | gotoop(s) | |
| 79 | char *s; | |
| 80 | { | |
| 81 | register struct nl *p; | |
| 82 | ||
| 83 | gocnt++; | |
| 84 | p = lookup(s); | |
| 85 | if (p == NIL) | |
| 86 | return (NIL); | |
| 87 | put2(O_TRA4, p->entloc); | |
| 88 | if (bn == cbn) | |
| 89 | if (p->nl_flags & NFORWD) { | |
| 90 | if (p->value[NL_GOLEV] == NOTYET) { | |
| 91 | p->value[NL_GOLEV] = level; | |
| 92 | p->value[NL_GOLINE] = line; | |
| 93 | } | |
| 94 | } else | |
| 95 | if (p->value[NL_GOLEV] == DEAD) { | |
| 96 | recovered(); | |
| 97 | error("Goto %s is into a structured statement", p->symbol); | |
| 98 | } | |
| 99 | } | |
| 100 | ||
| 101 | /* | |
| 102 | * Labeled is called when a label | |
| 103 | * definition is encountered, and | |
| 104 | * marks that it has been found and | |
| 105 | * patches the associated GOTO generated | |
| 106 | * by gotoop. | |
| 107 | */ | |
| 108 | labeled(s) | |
| 109 | char *s; | |
| 110 | { | |
| 111 | register struct nl *p; | |
| 112 | ||
| 113 | p = lookup(s); | |
| 114 | if (p == NIL) | |
| 115 | return (NIL); | |
| 116 | if (bn != cbn) { | |
| 117 | error("Label %s not defined in correct block", s); | |
| 118 | return; | |
| 119 | } | |
| 120 | if ((p->nl_flags & NFORWD) == 0) { | |
| 121 | error("Label %s redefined", s); | |
| 122 | return; | |
| 123 | } | |
| 124 | p->nl_flags &= ~NFORWD; | |
| 125 | patch4(p->entloc); | |
| 126 | if (p->value[NL_GOLEV] != NOTYET) | |
| 127 | if (p->value[NL_GOLEV] < level) { | |
| 128 | recovered(); | |
| 129 | error("Goto %s from line %d is into a structured statement", s, p->value[NL_GOLINE]); | |
| 130 | } | |
| 131 | p->value[NL_GOLEV] = level; | |
| 132 | } | |
| 133 | #endif |