/* This should find the caller's environment (it's a .Internal) and
then get the context of the call that owns the environment. As it
is, it will restart the wrong function if used in a promise.
L.T. */
SEXP attribute_hidden do_restart(SEXP call, SEXP op, SEXP args, SEXP rho)
{
RCNTXT *cptr;
checkArity(op, args);
if( !isLogical(CAR(args)) || LENGTH(CAR(args))!= 1 )
return(R_NilValue);
for(cptr = R_GlobalContext->nextcontext; cptr!= R_ToplevelContext;
cptr = cptr->nextcontext) {
if (cptr->callflag & CTXT_FUNCTION) {
SET_RESTART_BIT_ON(cptr->callflag);
break;
}
}
if( cptr == R_ToplevelContext )
error(_("no function to restart"));
return(R_NilValue);
}
/* browser(text = "", condition = NULL, expr = TRUE, skipCalls = 0L)
* ------- but also called from ./eval.c */
SEXP attribute_hidden do_browser(SEXP call, SEXP op, SEXP args, SEXP rho)
{
RCNTXT *saveToplevelContext;
RCNTXT *saveGlobalContext;
RCNTXT thiscontext, returncontext, *cptr;
int savestack, browselevel;
SEXP ap, topExp, argList;
/* argument matching */
PROTECT(ap = list4(R_NilValue, R_NilValue, R_NilValue, R_NilValue));
SET_TAG(ap, install("text"));
SET_TAG(CDR(ap), install("condition"));
SET_TAG(CDDR(ap), install("expr"));
SET_TAG(CDDDR(ap), install("skipCalls"));
argList = matchArgs(ap, args, call);
UNPROTECT(1);
PROTECT(argList);
/* substitute defaults */
if(CAR(argList) == R_MissingArg)
SETCAR(argList, mkString(""));
if(CADR(argList) == R_MissingArg)
SETCAR(CDR(argList), R_NilValue);
if(CADDR(argList) == R_MissingArg)
SETCAR(CDDR(argList), ScalarLogical(1));
if(CADDDR(argList) == R_MissingArg)
SETCAR(CDDDR(argList), ScalarInteger(0));
/* return if 'expr' is not TRUE */
if( !asLogical(CADDR(argList)) ) {
UNPROTECT(1);
return R_NilValue;
}
/* Save the evaluator state information */
/* so that it can be restored on exit. */
browselevel = countContexts(CTXT_BROWSER, 1);
savestack = R_PPStackTop;
PROTECT(topExp = R_CurrentExpr);
saveToplevelContext = R_ToplevelContext;
saveGlobalContext = R_GlobalContext;
if (!RDEBUG(rho)) {
int skipCalls = asInteger(CADDDR(argList));
cptr = R_GlobalContext;
while ( ( !(cptr->callflag & CTXT_FUNCTION) || skipCalls--)
&& cptr->callflag )
cptr = cptr->nextcontext;
Rprintf("Called from: ");
int tmp = asInteger(GetOption(install("deparse.max.lines"), R_BaseEnv));
if(tmp != NA_INTEGER && tmp > 0) R_BrowseLines = tmp;
if( cptr != R_ToplevelContext ) {
PrintValueRec(cptr->call, rho);
SET_RDEBUG(cptr->cloenv, 1);
} else
Rprintf("top level \n");
R_BrowseLines = 0;
}
R_ReturnedValue = R_NilValue;
/* Here we establish two contexts. The first */
/* of these provides a target for return */
/* statements which a user might type at the */
/* browser prompt. The (optional) second one */
/* acts as a target for error returns. */
begincontext(&returncontext, CTXT_BROWSER, call, rho,
R_BaseEnv, argList, R_NilValue);
if (!SETJMP(returncontext.cjmpbuf)) {
begincontext(&thiscontext, CTXT_RESTART, R_NilValue, rho,
R_BaseEnv, R_NilValue, R_NilValue);
if (SETJMP(thiscontext.cjmpbuf)) {
SET_RESTART_BIT_ON(thiscontext.callflag);
R_ReturnedValue = R_NilValue;
R_Visible = FALSE;
}
R_GlobalContext = &thiscontext;
R_InsertRestartHandlers(&thiscontext, TRUE);
R_ReplConsole(rho, savestack, browselevel+1);
endcontext(&thiscontext);
}
endcontext(&returncontext);
/* Reset the interpreter state. */
R_CurrentExpr = topExp;
UNPROTECT(1);
R_PPStackTop = savestack;
UNPROTECT(1);
R_CurrentExpr = topExp;
R_ToplevelContext = saveToplevelContext;
R_GlobalContext = saveGlobalContext;
return R_ReturnedValue;
}
