Research V7 development

[unix-history] / usr / src / cmd / adb / access.c

#
/*
*
*      UNIX debugger
*
*/

#include "defs.h"


MSG             ODDADR;
MSG             BADDAT;
MSG             BADTXT;
MAP             txtmap;
MAP             datmap;
INT             wtflag;
STRING          errflg;
INT             errno;

INT             pid;




/* file handling and access routines */

put(adr,space,value)
L_INT   adr;
{
       access(WT,adr,space,value);
}

POS     get(adr, space)
L_INT           adr;
{
       return(access(RD,adr,space,0));
}

POS     chkget(n, space)
L_INT           n;
{
       REG INT         w;

       w = get(n, space);
       chkerr();
       return(w);
}

access(mode,adr,space,value)
L_INT   adr;
{
       INT             w, w1, pmode, rd, file;
       rd = mode==RD;

       IF space == NSP THEN return(0); FI

       IF pid          /* tracing on? */
       THEN IF (adr&01) ANDF !rd THEN error(ODDADR); FI
            pmode = (space&DSP?(rd?RDUSER:WDUSER):(rd?RIUSER:WIUSER));
            w = ptrace(pmode, pid, shorten(adr&~01), value);
            IF adr&01
            THEN w1 = ptrace(pmode, pid, shorten(adr+1), value);
                 w = (w>>8)&LOBYTE | (w1<<8);
            FI
            IF errno
            THEN errflg = (space&DSP ? BADDAT : BADTXT);
            FI
            return(w);
       FI
       w = 0;
       IF mode==WT ANDF wtflag==0
       THEN    error("not in write mode");
       FI
       IF !chkmap(&adr,space)
       THEN return(0);
       FI
       file=(space&DSP?datmap.ufd:txtmap.ufd);
       IF longseek(file,adr)==0 ORF
          (rd ? read(file,&w,2) : write(file,&value,2)) < 1
       THEN    errflg=(space&DSP?BADDAT:BADTXT);
       FI
       return(w);

}

chkmap(adr,space)
       REG L_INT       *adr;
       REG INT         space;
{
       REG MAPPTR amap;
       amap=((space&DSP?&datmap:&txtmap));
       IF space&STAR ORF !within(*adr,amap->b1,amap->e1)
       THEN IF within(*adr,amap->b2,amap->e2)
            THEN *adr += (amap->f2)-(amap->b2);
            ELSE errflg=(space&DSP?BADDAT:BADTXT); return(0);
            FI
       ELSE *adr += (amap->f1)-(amap->b1);
       FI
       return(1);
}

within(adr,lbd,ubd)
L_INT   adr, lbd, ubd;
{
       return(adr>=lbd && adr<ubd);
}