1 /* Copyright (c) 1982 Regents of the University of California */ 2 3 static char sccsid[] = "@(#)readsym.c 1.2 01/19/82"; 4 5 /* 6 * SYM representation dependent routines for reading in the 7 * symbol information from the object file. 8 */ 9 10 #include "defs.h" 11 #include "sym.h" 12 #include "symtab.h" 13 #include "object.h" 14 #include "objfmt.h" 15 #include "process.h" 16 #include "sym/classes.h" 17 #include "objsym.rep" 18 #include "sym/sym.rep" 19 20 LOCAL SYM *findblock(); 21 LOCAL SYM *enterblock(); 22 LOCAL SYM *findfunc(); 23 24 /* 25 * Read the information on a symbol from the object file, return a 26 * SYM with the info. 27 */ 28 29 SYM *readsym(fp) 30 FILE *fp; 31 { 32 register SYM *s, *t; 33 SYM cursym; 34 static SYM *func; 35 36 t = &cursym; 37 getsym(fp, t); 38 if (isblock(t)) { 39 # if (isvaxpx) 40 if (t->class == PROG) { 41 t->symvalue.funcv.codeloc = HEADER_BYTES; 42 } 43 # endif 44 s = findblock(t); 45 if (s->class == PROG) { 46 program = s; 47 s->func = NIL; 48 } else { 49 s->func = func; 50 } 51 } else if (t->class == BADUSE) { 52 func = enterblock(t); 53 return(func); 54 } else { 55 s = st_insert(symtab, t->symbol); 56 t->next_sym = s->next_sym; 57 *s = *t; 58 if (s->class == FVAR) { 59 s->func = findfunc(s); 60 } else { 61 s->func = func; 62 } 63 } 64 65 /* 66 * This glitch is pi's fault. It gives string constants 67 * a type whose symbol number is -1. For what reason, I know not. 68 */ 69 if (s->type == (SYM *) -1) { 70 s->type = NIL; 71 } else { 72 chkpatch(&s->type); 73 } 74 chkpatch(&s->chain); 75 if (s->class == RECORD || s->class == VARNT) { 76 chkpatch(&s->symvalue.varnt.vtorec); 77 chkpatch(&s->symvalue.varnt.vtag); 78 } 79 if (isblock(s)) { 80 fixparams(s); 81 } 82 return(s); 83 } 84 85 /* 86 * Read the SYM information in the object file. 87 */ 88 89 LOCAL getsym(fp, t) 90 FILE *fp; 91 SYM *t; 92 { 93 OBJSYM osym; 94 register OBJSYM *o; 95 96 get(fp, osym); 97 o = &osym; 98 if (o->strindex == 0) { 99 t->symbol = NIL; 100 } else { 101 t->symbol = &stringtab[o->strindex]; 102 } 103 t->class = o->oclass; 104 t->blkno = o->oblkno; 105 t->type = (SYM *) o->typno; 106 t->chain = (SYM *) o->chno; 107 t->symvalue.rangev.lower = o->osymvalue.orangev.lower; 108 t->symvalue.rangev.upper = o->osymvalue.orangev.upper; 109 if (t->class == RECORD || t->class == VARNT) { 110 t->symvalue.varnt.vtorec = (SYM *) o->osymvalue.ovarnt.vtorecno; 111 t->symvalue.varnt.vtag = (SYM *) o->osymvalue.ovarnt.vtagno; 112 } 113 } 114 115 /* 116 * The symbol read in is a real block so we find it's entry, 117 * copy the information, and return a pointer to it. 118 */ 119 120 LOCAL SYM *findblock(t) 121 SYM *t; 122 { 123 SYM *s; 124 125 s = st_lookup(symtab, t->symbol); 126 while (s != NIL && 127 (s->class != FUNC || s->type != NIL || 128 strcmp(s->symbol, t->symbol) != 0)) { 129 s = s->next_sym; 130 } 131 if (s == NIL) { 132 panic("can't find %s", t->symbol); 133 } 134 t->next_sym = s->next_sym; 135 *s = *t; 136 s->symvalue.funcv.codeloc -= HEADER_BYTES; 137 findbeginning(s); 138 newfunc(s); 139 return(s); 140 } 141 142 /* 143 * Found a "fake" block symbol, enter it. 144 */ 145 146 LOCAL SYM *enterblock(t) 147 SYM *t; 148 { 149 SYM *s; 150 151 s = st_insert(symtab, t->symbol); 152 t->next_sym = s->next_sym; 153 *s = *t; 154 backpatch(); 155 s->class = FUNC; 156 s->type = NIL; 157 return(s); 158 } 159 160 /* 161 * This kludge is brought to you by the pi symbol table. 162 * Parameters appear with the function in which they reside, 163 * messing up the way the "func" field is calculated. 164 * 165 * The assumption here is that parameters appear before the function. 166 */ 167 168 LOCAL fixparams(f) 169 SYM *f; 170 { 171 register SYM *s; 172 173 for (s = f->chain; s != NIL; s = s->chain) { 174 s->func = f; 175 } 176 } 177 178 /* 179 * Find the function entry associated with a function variable. 180 * Function variables come out a bit strangely in the symbol table; 181 * if we didn't do this here, a function variable would have a func 182 * field that referred to the outer block. 183 */ 184 185 #define notfunc(f, fv) (\ 186 f->class != FUNC || f->type != NIL || \ 187 strcmp(f->symbol, fv->symbol) != 0 \ 188 ) 189 190 LOCAL SYM *findfunc(fv) 191 SYM *fv; 192 { 193 register SYM *t; 194 195 t = st_lookup(symtab, fv->symbol); 196 while (t != NIL && notfunc(t, fv)) { 197 t = t->next_sym; 198 } 199 if (t == NIL) { 200 panic("no func for funcvar %s", fv->symbol); 201 } 202 return(t); 203 } 204