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Annotation of 43BSDTahoe/ucb/pascal/pdx/object/readsym.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1980 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: 
        !             7: #ifndef lint
        !             8: static char sccsid[] = "@(#)readsym.c  5.2 (Berkeley) 4/7/87";
        !             9: #endif not lint
        !            10: /*
        !            11:  * SYM representation dependent routines for reading in the
        !            12:  * symbol information from the object file.
        !            13:  */
        !            14: 
        !            15: #include "defs.h"
        !            16: #include "sym.h"
        !            17: #include "symtab.h"
        !            18: #include "object.h"
        !            19: #include "objfmt.h"
        !            20: #include "process.h"
        !            21: #include "sym/classes.h"
        !            22: #include "objsym.rep"
        !            23: #include "sym/sym.rep"
        !            24: 
        !            25: LOCAL SYM *findblock();
        !            26: LOCAL SYM *enterblock();
        !            27: LOCAL SYM *findfunc();
        !            28: 
        !            29: /*
        !            30:  * Read the information on a symbol from the object file, return a
        !            31:  * SYM with the info.
        !            32:  */
        !            33: 
        !            34: SYM *readsym(fp)
        !            35: FILE *fp;
        !            36: {
        !            37:     register SYM *s, *t;
        !            38:     SYM cursym;
        !            39:     static SYM *func;
        !            40: 
        !            41:     t = &cursym;
        !            42:     getsym(fp, t);
        !            43:     if (isblock(t)) {
        !            44:        if (t->class == PROG) {
        !            45:            t->symvalue.funcv.codeloc = HEADER_BYTES;
        !            46:        }
        !            47:        s = findblock(t);
        !            48:        if (s->class == PROG) {
        !            49:            program = s;
        !            50:            s->func = NIL;
        !            51:        } else {
        !            52:            s->func = func;
        !            53:        }
        !            54:     } else if (t->class == BADUSE) {
        !            55:        func = enterblock(t);
        !            56:        return(func);
        !            57:     } else {
        !            58:        s = st_insert(symtab, t->symbol);
        !            59:        t->next_sym = s->next_sym;
        !            60:        *s = *t;
        !            61:        if (s->class == FVAR) {
        !            62:            s->func = findfunc(s);
        !            63:        } else {
        !            64:            s->func = func;
        !            65:        }
        !            66:     }
        !            67: 
        !            68: /*
        !            69:  * This glitch is pi's fault.  It gives string constants
        !            70:  * a type whose symbol number is -1.  For what reason, I know not.
        !            71:  */
        !            72:     if (s->type == (SYM *) -1) {
        !            73:        s->type = NIL;
        !            74:     } else {
        !            75:        chkpatch(&s->type);
        !            76:     }
        !            77:     chkpatch(&s->chain);
        !            78:     if (s->class == RECORD || s->class == VARNT) {
        !            79:        chkpatch(&s->symvalue.varnt.vtorec);
        !            80:        chkpatch(&s->symvalue.varnt.vtag);
        !            81:     }
        !            82:     if (isblock(s)) {
        !            83:        fixparams(s);
        !            84:     }
        !            85:     return(s);
        !            86: }
        !            87: 
        !            88: /*
        !            89:  * Read the SYM information in the object file.
        !            90:  */
        !            91: 
        !            92: LOCAL getsym(fp, t)
        !            93: FILE *fp;
        !            94: SYM *t;
        !            95: {
        !            96:     OBJSYM osym;
        !            97:     register OBJSYM *o;
        !            98: 
        !            99:     get(fp, osym);
        !           100:     o = &osym;
        !           101:     if (o->strindex == 0) {
        !           102:        t->symbol = NIL;
        !           103:     } else {
        !           104:        t->symbol = &stringtab[o->strindex];
        !           105:     }
        !           106:     t->class = o->oclass;
        !           107:     t->blkno = o->oblkno;
        !           108:     t->type = (SYM *) o->typno;
        !           109:     t->chain = (SYM *) o->chno;
        !           110:     t->symvalue.rangev.lower = o->osymvalue.orangev.lower;
        !           111:     t->symvalue.rangev.upper = o->osymvalue.orangev.upper;
        !           112:     if (t->class == RECORD || t->class == VARNT) {
        !           113:        t->symvalue.varnt.vtorec = (SYM *) o->osymvalue.ovarnt.vtorecno;
        !           114:        t->symvalue.varnt.vtag = (SYM *) o->osymvalue.ovarnt.vtagno;
        !           115:     }
        !           116: }
        !           117: 
        !           118: /*
        !           119:  * The symbol read in is a real block so we find it's entry,
        !           120:  * copy the information, and return a pointer to it.
        !           121:  */
        !           122: 
        !           123: LOCAL SYM *findblock(t)
        !           124: SYM *t;
        !           125: {
        !           126:     SYM *s;
        !           127: 
        !           128:     s = st_lookup(symtab, t->symbol);
        !           129:     while (s != NIL &&
        !           130:        (s->class != FUNC || s->type != NIL ||
        !           131:        strcmp(s->symbol, t->symbol) != 0)) {
        !           132:        s = s->next_sym;
        !           133:     }
        !           134:     if (s == NIL) {
        !           135:        panic("can't find %s", t->symbol);
        !           136:     }
        !           137:     t->next_sym = s->next_sym;
        !           138:     *s = *t;
        !           139:     s->symvalue.funcv.codeloc -= HEADER_BYTES;
        !           140:     findbeginning(s);
        !           141:     newfunc(s);
        !           142:     return(s);
        !           143: }
        !           144: 
        !           145: /*
        !           146:  * Found a "fake" block symbol, enter it.
        !           147:  */
        !           148: 
        !           149: LOCAL SYM *enterblock(t)
        !           150: SYM *t;
        !           151: {
        !           152:     SYM *s;
        !           153: 
        !           154:     s = st_insert(symtab, t->symbol);
        !           155:     t->next_sym = s->next_sym;
        !           156:     *s = *t;
        !           157:     backpatch();
        !           158:     s->class = FUNC;
        !           159:     s->type = NIL;
        !           160:     return(s);
        !           161: }
        !           162: 
        !           163: /*
        !           164:  * This kludge is brought to you by the pi symbol table.
        !           165:  * Parameters appear with the function in which they reside,
        !           166:  * messing up the way the "func" field is calculated.
        !           167:  *
        !           168:  * The assumption here is that parameters appear before the function.
        !           169:  */
        !           170: 
        !           171: LOCAL fixparams(f)
        !           172: SYM *f;
        !           173: {
        !           174:     register SYM *s;
        !           175: 
        !           176:     for (s = f->chain; s != NIL; s = s->chain) {
        !           177:        s->func = f;
        !           178:     }
        !           179: }
        !           180: 
        !           181: /*
        !           182:  * Find the function entry associated with a function variable.
        !           183:  * Function variables come out a bit strangely in the symbol table;
        !           184:  * if we didn't do this here, a function variable would have a func
        !           185:  * field that referred to the outer block.
        !           186:  */
        !           187: 
        !           188: #define notfunc(f, fv) (\
        !           189:     f->class != FUNC || f->type != NIL || \
        !           190:     strcmp(f->symbol, fv->symbol) != 0 \
        !           191:     )
        !           192: 
        !           193: LOCAL SYM *findfunc(fv)
        !           194: SYM *fv;
        !           195: {
        !           196:     register SYM *t;
        !           197: 
        !           198:     t = st_lookup(symtab, fv->symbol);
        !           199:     while (t != NIL && notfunc(t, fv)) {
        !           200:        t = t->next_sym;
        !           201:     }
        !           202:     if (t == NIL) {
        !           203:        panic("no func for funcvar %s", fv->symbol);
        !           204:     }
        !           205:     return(t);
        !           206: }

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