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Annotation of 42BSD/ucb/pascal/pdx/object/readsym.c, revision 1.1

1.1     ! root        1: /* Copyright (c) 1982 Regents of the University of California */
        !             2: 
        !             3: static char sccsid[] = "@(#)readsym.c 1.3 5/19/82";
        !             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: }

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