projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 5d709883 ML |
1 | /* Copyright (c) 1982 Regents of the University of California */ |
| 2 | ||
| 280603e7 | 3 | static char sccsid[] = "@(#)predicates.c 1.2 %G%"; |
| 5d709883 ML |
4 | |
| 5 | /* | |
| 6 | * The basic tests on a symbol. | |
| 7 | */ | |
| 8 | ||
| 9 | #include "defs.h" | |
| 10 | #include "sym.h" | |
| 11 | #include "symtab.h" | |
| 280603e7 | 12 | #include "btypes.h" |
| 5d709883 ML |
13 | #include "classes.h" |
| 14 | #include "sym.rep" | |
| 15 | ||
| 16 | /* | |
| 17 | * Test if a symbol is a parameter. This is true if there | |
| 18 | * is a cycle from s->func to s via chain pointers. | |
| 19 | */ | |
| 20 | ||
| 21 | BOOLEAN isparam(s) | |
| 22 | SYM *s; | |
| 23 | { | |
| 24 | register SYM *t; | |
| 25 | ||
| 26 | for (t = s->func; t != NIL; t = t->chain) { | |
| 27 | if (t == s) { | |
| 28 | return(TRUE); | |
| 29 | } | |
| 30 | } | |
| 31 | return(FALSE); | |
| 32 | } | |
| 33 | ||
| 34 | /* | |
| 35 | * Test if a symbol is a var parameter, i.e. has class REF. | |
| 36 | */ | |
| 37 | ||
| 38 | BOOLEAN isvarparam(s) | |
| 39 | SYM *s; | |
| 40 | { | |
| 41 | return (BOOLEAN) s->class == REF; | |
| 42 | } | |
| 43 | ||
| 44 | /* | |
| 45 | * Test if a symbol is a block, e.g. function, procedure, or the | |
| 46 | * main program. | |
| 47 | */ | |
| 48 | ||
| 49 | BOOLEAN isblock(s) | |
| 50 | register SYM *s; | |
| 51 | { | |
| 52 | return(s->class == FUNC || s->class == PROC || s->class == PROG); | |
| 53 | } | |
| 54 | ||
| 55 | /* | |
| 56 | * Test if a symbol is builtin, that is, a predefined type or | |
| 57 | * reserved word. | |
| 58 | */ | |
| 59 | ||
| 60 | BOOLEAN isbuiltin(s) | |
| 61 | SYM *s; | |
| 62 | { | |
| 63 | return(s->blkno == 0 && s->class != PROG && s->class != VAR); | |
| 64 | } | |
| 65 | ||
| 66 | /* | |
| 67 | * Compatible tests if two types are compatible. The issue | |
| 68 | * is complicated a bit by ranges. | |
| 69 | * | |
| 70 | * Integers and reals are not compatible since they cannot always be mixed. | |
| 71 | */ | |
| 72 | ||
| 73 | BOOLEAN compatible(t1, t2) | |
| 74 | register SYM *t1, *t2; | |
| 75 | { | |
| 76 | if (t1 == t2) { | |
| 77 | return(TRUE); | |
| 78 | } | |
| 79 | t1 = rtype(t1); | |
| 80 | t2 = rtype(t2); | |
| 81 | if (t1->type == t2->type) { | |
| 82 | if (t1->class == RANGE && t2->class == RANGE) { | |
| 83 | return TRUE; | |
| 84 | } | |
| 85 | if ((t1->class == SCAL || t1->class == CONST) && | |
| 86 | (t2->class == SCAL || t2->class == CONST)) { | |
| 87 | return TRUE; | |
| 88 | } | |
| 280603e7 ML |
89 | if (t1->type == t_char && t1->class == ARRAY && t2->class == ARRAY) { |
| 90 | return TRUE; | |
| 91 | } | |
| 5d709883 ML |
92 | } |
| 93 | /* | |
| 94 | * A kludge here for "nil". Should be handled better. | |
| 95 | * Opens a pandora's box for integer/pointer compatibility. | |
| 96 | */ | |
| 97 | if (t1->class == RANGE && t2->class == PTR) { | |
| 98 | return TRUE; | |
| 99 | } | |
| 100 | if (t2->class == RANGE && t1->class == PTR) { | |
| 101 | return TRUE; | |
| 102 | } | |
| 103 | return(FALSE); | |
| 104 | } | |
| 105 | ||
| 106 | /* | |
| 107 | * Predicate to test if a symbol should be printed. We don't print | |
| 108 | * files, for example, simply because there's no good way to do it. | |
| 109 | * The symbol must be within the given function. | |
| 110 | */ | |
| 111 | ||
| 112 | BOOLEAN should_print(s, f) | |
| 113 | SYM *s; | |
| 114 | SYM *f; | |
| 115 | { | |
| 116 | SYM *t; | |
| 117 | ||
| 118 | if (s->func != f || (s->class != VAR && s->class != FVAR)) { | |
| 119 | return(FALSE); | |
| 120 | } else if (s->chain != NIL) { | |
| 121 | return(FALSE); | |
| 122 | } else { | |
| 123 | t = rtype(s->type); | |
| 280603e7 | 124 | if (t == NIL || t->class == FILET || t->class == SET) { |
| 5d709883 ML |
125 | return(FALSE); |
| 126 | } else { | |
| 127 | return(TRUE); | |
| 128 | } | |
| 129 | } | |
| 130 | } | |
| 131 | ||
| 132 | /* | |
| 133 | * Test if the name of a symbol is uniquely defined or not. | |
| 134 | */ | |
| 135 | ||
| 136 | BOOLEAN isambiguous(s) | |
| 137 | SYM *s; | |
| 138 | { | |
| 139 | SYM *t; | |
| 140 | ||
| 141 | t = st_lookup(symtab, s->symbol); | |
| 142 | if (t == NIL) { | |
| 143 | panic("symbol name vanished"); | |
| 144 | } | |
| 145 | while (t != NIL && (s == t || !streq(t->symbol, s->symbol))) { | |
| 146 | t = t->next_sym; | |
| 147 | } | |
| 148 | return t != NIL; | |
| 149 | } |