BSD 4_3 release

[unix-history] / usr / src / ucb / dbx / tree.c

/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/

#ifndef lint
static char sccsid[] = "@(#)tree.c      5.1 (Berkeley) 5/31/85";
#endif not lint

static char rcsid[] = "$Header: tree.c,v 1.5 84/12/26 10:42:55 linton Exp $";

/*
* Parse tree management.
*/

#include "defs.h"
#include "tree.h"
#include "operators.h"
#include "debug.h"
#include "eval.h"
#include "events.h"
#include "symbols.h"
#include "scanner.h"
#include "source.h"
#include "object.h"
#include "mappings.h"
#include "process.h"
#include "machine.h"

#ifndef public
#include "lists.h"

typedef struct Node *Node;
typedef Node Command;
typedef List Cmdlist;

#include "operators.h"
#include "symbols.h"
#include "events.h"

#define MAXNARGS 5

struct Node {
   Operator op;
   Symbol nodetype;
   union treevalue {
       Symbol sym;
       Name name;
       long lcon;
       double fcon;
       String scon;
       Node arg[MAXNARGS];
       struct {
           Node cond;
           Cmdlist actions;
       } event;
       struct {
           Boolean inst;
           Event event;
           Cmdlist actions;
       } trace;
       struct {
           Boolean source;
           Boolean skipcalls;
       } step;
       struct {
           String mode;
           Node beginaddr;
           Node endaddr;
           Integer count;
       } examine;
   } value;
};

#define evalcmd(cmd) eval(cmd)
#define cmdlist_append(cmd, cl) list_append(list_item(cmd), nil, cl)

#endif

typedef char *Arglist;

#define nextarg(type)  ((type *) (ap += sizeof(type)))[-1]

/*
* Build a tree.
*/

/* VARARGS1 */
public Node build(op, args)
Operator op;
{
   register Node p, q;
   register Arglist ap;
   Integer i;

   p = new(Node);
   p->op = op;
   p->nodetype = nil;
   ap = (Arglist) &args;
   switch (op) {
       case O_NAME:
           p->value.name = nextarg(Name);
           break;

       case O_SYM:
       case O_PRINTCALL:
       case O_PRINTRTN:
       case O_PROCRTN:
           p->value.sym = nextarg(Symbol);
           break;

       case O_DEBUG:
       case O_LCON:
       case O_CCON:
       case O_CONT:
       case O_CATCH:
       case O_IGNORE:
       case O_TRACEOFF:
           p->value.lcon = nextarg(long);
           break;

       case O_FCON:
           p->value.fcon = nextarg(double);
           break;

       case O_SCON:
       case O_CHFILE:
       case O_EDIT:
       case O_SOURCE:
           p->value.scon = nextarg(String);
           break;

       case O_RVAL:
       case O_INDIR:
           p->value.arg[0] = nextarg(Node);
           break;

       case O_CALL:
           q = nextarg(Node);
           if (q->op == O_SYM and
               (q->value.sym->class == TYPE or q->value.sym->class == TAG)
           ) {
               p->op = O_TYPERENAME;
               p->value.arg[0] = nextarg(Node);
               p->value.arg[1] = q;
               q = p->value.arg[0];
               if (q->value.arg[1] != nil) {
                   error("too many arguments to type rename");
               }
               p->value.arg[0] = q->value.arg[0];
           } else {
               p->value.arg[0] = q;
               p->value.arg[1] = nextarg(Node);
           }
           break;

       case O_ADDEVENT:
       case O_ONCE:
       case O_IF:
           p->value.event.cond = nextarg(Node);
           p->value.event.actions = nextarg(Cmdlist);
           break;

       case O_TRACEON:
           p->value.trace.inst = nextarg(Boolean);
           p->value.trace.event = nil;
           p->value.trace.actions = nextarg(Cmdlist);
           break;

       case O_STEP:
           p->value.step.source = nextarg(Boolean);
           p->value.step.skipcalls = nextarg(Boolean);
           break;

       case O_EXAMINE:
           p->value.examine.mode = nextarg(String);
           p->value.examine.beginaddr = nextarg(Node);
           p->value.examine.endaddr = nextarg(Node);
           p->value.examine.count = nextarg(Integer);
           break;

       default:
           for (i = 0; i < nargs(op); i++) {
               p->value.arg[i] = nextarg(Node);
           }
           break;
   }
   check(p);
   assigntypes(p);
   if (tracetree) {     
       printf("built %s node 0x%x with arg[0] 0x%x arg[1] 0x%x\n",
           opname(p->op), p, p->value.arg[0], p->value.arg[1]);
       fflush(stdout);
   }
   return p;
}

/*
* Strip away indirection from a node, thus returning a node for
* interpreting the expression as an lvalue.
*/

public Node unrval (exp)
Node exp;
{
   Node p;
   Symbol t;

   if (exp->op == O_RVAL) {
       p = exp->value.arg[0];
       dispose(exp);
   } else if (exp->op == O_INDIR) {
       p = exp->value.arg[0];
       if (p->op == O_RVAL) {
           p->op = O_INDIR;
           p->nodetype = exp->nodetype;
       }
       dispose(exp);
   } else {
       p = exp;
   }
   return p;
}

/*
* Create a node for renaming a node to a pointer type.
*/

public Node renameptr (p, t)
Node p;
Node t;
{
   t->nodetype = newSymbol(nil, 0, PTR, t->nodetype, nil);
   p = build(O_TYPERENAME, p, t);
}

/*
* Return the tree for a unary ampersand operator.
*/

public Node amper(p)
Node p;
{
   Node r;

   checkref(p);
   switch (p->op) {
       case O_RVAL:
       case O_INDIR:
           r = p->value.arg[0];
           r->nodetype = t_addr;
           dispose(p);
           break;

       case O_TYPERENAME:
           r = p;
           r->nodetype = newSymbol(nil, 0, PTR, r->nodetype, nil);
           break;

       case O_SYM:
           if (isblock(p->value.sym)) {
               r = build(O_LCON, codeloc(p->value.sym));
           } else {
               r = build(O_LCON, address(p->value.sym, nil));
           }
           r->nodetype = t_addr;
           dispose(p);
           break;

       case O_DOT:
           r = p;
           r->nodetype = t_addr;
           break;

       default:
           beginerrmsg();
           fprintf(stderr, "expected variable, found \"");
           prtree(stderr, p);
           fprintf(stderr, "\"");
           tfree(p);
           enderrmsg();
           /* NOTREACHED */
   }
   return r;
}

/*
* Create a "concrete" version of a node.
* This is necessary when the type of the node contains
* an unresolved type reference.
*/

public Node concrete(p)
Node p;
{
   findtype(p->nodetype);
   return build(O_INDIR, p);
}

/*
* Create a command list from a single command.
*/

public Cmdlist buildcmdlist(cmd)
Command cmd;
{
   Cmdlist cmdlist;

   cmdlist = list_alloc();
   cmdlist_append(cmd, cmdlist);
   return cmdlist;
}

/*
* Print out a command.
*/

public printcmd(f, cmd)
File f;
Command cmd;
{
   register Integer i;
   register Command c;
   register Node p;

   switch (cmd->op) {
       case O_PRINTIFCHANGED:
       case O_PRINTSRCPOS:
       case O_STOPIFCHANGED:
       case O_TRACEON:
           break;

       case O_STEP:
           if (cmd->value.step.skipcalls) {
               fprintf(f, "next");
           } else {
               fprintf(f, "step");
           }
           if (not cmd->value.step.source) {
               fprintf(f, "i");
           }
           break;

       default:
           fprintf(f, "%s", opinfo[ord(cmd->op)].opstring);
           if (nargs(cmd->op) != 0) {
               fprintf(f, " ");
           }
           break;
   }
   switch (cmd->op) {
       case O_PRINTCALL:
       case O_PRINTRTN:
       case O_PROCRTN:
           fprintf(f, "%s", symname(cmd->value.sym));
           break;

       case O_PRINTSRCPOS:
           p = cmd->value.arg[0];
           if (p != nil and p->op != O_QLINE) {
               printf("trace ");
               prtree(f, p);
           }
           break;

       case O_CHFILE:
       case O_EDIT:
       case O_SOURCE:
           fprintf(f, "%s", cmd->value.scon);
           break;

       case O_CATCH:
       case O_IGNORE:
       case O_TRACEOFF:
           fprintf(f, "%d", cmd->value.lcon);
           break;

       case O_ADDEVENT:
       case O_ONCE:
       case O_IF:
           fprintf(f, " ");
           prtree(f, cmd->value.event.cond);
           fprintf(f, " { ");
           foreach (Command, c, cmd->value.event.actions)
               printcmd(f, c);
               if (not list_islast()) {
                   fprintf(f, ";");
               }
           endfor
           fprintf(f, " }", opinfo[ord(cmd->op)].opstring);
           break;

       case O_TRACEON:
           print_tracestop(f, cmd);
           break;

       case O_EXAMINE:
           prtree(f, cmd->value.examine.beginaddr);
           if (cmd->value.examine.endaddr != nil) {
               fprintf(f, ",");
               prtree(f, cmd->value.examine.endaddr);
           }
           fprintf(f, "/");
           if (cmd->value.examine.count > 1) {
               fprintf(f, "%d", cmd->value.examine.count);
           }
           fprintf("%s", cmd->value.examine.mode);
           break;

       default:
           if (nargs(cmd->op) != 0) {
               i = 0;
               for (;;) {
                   prtree(f, cmd->value.arg[i]);
                   ++i;
               if (i >= nargs(cmd->op)) break;
                   fprintf(f, " ");
               }
           }
           break;
   }
}

/*
* Print out a trace/stop command name.
*/

#define fprintI(f, b) { if (b) fprintf(f, "i"); }

private print_tracestop(f, cmd)
File f;
Command cmd;
{
   register Command c, ifcmd, stopcmd;
   Boolean done;

   done = false;
   ifcmd = list_element(Command, list_head(cmd->value.trace.actions));
   checkref(ifcmd);
   if (ifcmd->op == O_IF) {
       stopcmd = list_element(Command, list_head(ifcmd->value.event.actions));
       checkref(stopcmd);
       if (stopcmd->op == O_STOPX) {
           fprintf(f, "stop");
           fprintI(f, cmd->value.trace.inst);
           fprintf(f, " if ");
           prtree(f, ifcmd->value.event.cond);
           done = true;
       }
   } else if (ifcmd->op == O_STOPIFCHANGED) {
       fprintf(f, "stop");
       fprintI(f, cmd->value.trace.inst);
       fprintf(f, " ");
       prtree(f, ifcmd->value.arg[0]);
       done = true;
   }
   if (not done) {
       fprintf(f, "%s ", cmd->value.trace.inst ? "tracei" : "trace");
       foreach (Command, c, cmd->value.trace.actions)
           printcmd(f, c);
           if (not list_islast()) {
               fprintf(f, ";");
           }
       endfor
   }
}

/*
* Print out a tree.
*/

public prtree(f, p)
File f;
register Node p;
{
   register Node q;
   Operator op;

   if (p != nil) {
       op = p->op;
       if (ord(op) > ord(O_LASTOP)) {
           panic("bad op %d in prtree", p->op);
       }
       switch (op) {
           case O_NAME:
               fprintf(f, "%s", ident(p->value.name));
               break;

           case O_SYM:
               printname(f, p->value.sym);
               break;

           case O_QLINE:
               if (nlhdr.nfiles > 1) {
                   prtree(f, p->value.arg[0]);
                   fprintf(f, ":");
               }
               prtree(f, p->value.arg[1]);
               break;

           case O_LCON:
               fprintf(f, "%d", p->value.lcon);
               break;

           case O_CCON:
               fprintf(f, "'%c'", p->value.lcon);
               break;

           case O_FCON:
               fprintf(f, "%g", p->value.fcon);
               break;

           case O_SCON:
               fprintf(f, "\"%s\"", p->value.scon);
               break;

           case O_INDEX:
               prtree(f, p->value.arg[0]);
               fprintf(f, "[");
               prtree(f, p->value.arg[1]);
               fprintf(f, "]");
               break;

           case O_COMMA:
               prtree(f, p->value.arg[0]);
               if (p->value.arg[1] != nil) {
                   fprintf(f, ", ");
                   prtree(f, p->value.arg[1]);
               }
               break;

           case O_RVAL:
           case O_ITOF:
               prtree(f, p->value.arg[0]);
               break;

           case O_CALL:
               prtree(f, p->value.arg[0]);
               if (p->value.arg[1]!= nil) {
                   fprintf(f, "(");
                   prtree(f, p->value.arg[1]);
                   fprintf(f, ")");
               }
               break;

           case O_INDIR:
               prtree(f, p->value.arg[0]);
               fprintf(f, "^");
               break;

           case O_DOT:
               prtree(f, p->value.arg[0]);
               fprintf(f, ".%s", symname(p->value.arg[1]->value.sym));
               break;

           case O_TYPERENAME:
               prtree(f, p->value.arg[1]);
               fprintf(f, "(");
               prtree(f, p->value.arg[0]);
               fprintf(f, ")");
               break;

           default:
               switch (degree(op)) {
                   case BINARY:
                       prtree(f, p->value.arg[0]);
                       fprintf(f, "%s", opinfo[ord(op)].opstring);
                       prtree(f, p->value.arg[1]);
                       break;

                   case UNARY:
                       fprintf(f, "%s", opinfo[ord(op)].opstring);
                       prtree(f, p->value.arg[0]);
                       break;

                   default:
                       if (opinfo[ord(op)].opstring == nil) {
                           fprintf(f, "[op %d]", ord(op));
                       } else {
                           fprintf(f, "%s", opinfo[ord(op)].opstring);
                       }
                       break;
               }
               break;
       }
   }
}

/*
* Free storage associated with a tree.
*/

public tfree(p)
Node p;
{
   Integer i;

   if (p == nil) {
       return;
   }
   switch (p->op) {
       case O_QLINE:
           dispose(p->value.arg[0]->value.scon);
           dispose(p->value.arg[0]);
           tfree(p->value.arg[1]);
           break;

       case O_SCON:
           unmkstring(p->nodetype);
           dispose(p->nodetype);
           dispose(p->value.scon);
           break;

       default:
           for (i = 0; i < nargs(p->op); i++) {
               tfree(p->value.arg[i]);
           }
           break;
   }
   dispose(p);
}