Working on better handling of multithreading in general

and core dumps in particular.  See notes:

new types: register is something that when dereferenced gives you
	the registers.  the Ureg is no longer mapped at 0.
	refconst is something that gives a constant when dereferenced.

new builtin register("AX") creates register values
new builtin refconst(0x123) creates refconst values

new builtin var("foo") is equivalent to the variable foo
	(it returns foo but can also be used as the lhs of an assignment).

new acid function getregs() returns a list of the current values of registers.
new acid function setregs() sets the current registers to those values.
	note that getregs and setregs operate on register locations, not the
		register values themselves.
new acid function resetregs() sets registers to register("AX"), etc.
new acid function clearregs() sets all registers to constant -1.
the default register settings are as in resetregs(), not small numbers.

new acid variables coretext, pids, systype, corefile, cmdline.

new behavior: local variable lookup, stk, etc., use the acid values of registers
	(*PC, *SP, and so on), so the thread support code can change the context
	completely.

unary + is applicable to more data types and prints more often.

1 files changed, 109 insertions, 20 deletions

diff --git a/src/cmd/acid/expr.c b/src/cmd/acid/expr.c
index 9cfac9e3..6a0430dc 100644
--- a/src/cmd/acid/expr.c
+++ b/src/cmd/acid/expr.c
@@ -63,11 +63,29 @@ fmtsize(Value *v)
 	}
 }
 
-void
+Lsym*
 chklval(Node *lp)
 {
-	if(lp->op != ONAME)
-		error("need l-value");
+	Node res;
+	Lsym *s;
+
+	if(lp->op == ONAME)
+		return lp->sym;
+
+	if(lp->op == OCALL){
+		s = chklval(lp->left);
+		if(strcmp(s->name, "var") == 0	
+		&& (lp->builtin || s->proc == 0)){
+			if(lp->right == 0)
+				error("var(string): arg count");
+			expr(lp->right, &res);
+			if(res.type != TSTRING)
+				error("var(string): arg type");
+			return mkvar(res.store.u.string->string);
+		}
+	}
+	error("need l-value");
+	return nil;	
 }
 
 void
@@ -107,12 +125,24 @@ oindm(Node *n, Node *res)
 	if(m == 0)
 		m = symmap;
 	expr(n->left, &l);
-	if(l.type != TINT)
+	switch(l.type){
+	default:
 		error("bad type for *");
-	if(m == 0)
-		error("no map for *");
-	indir(m, l.store.u.ival, l.store.fmt, res);
-	res->store.comt = l.store.comt;
+	case TINT:
+		if(m == 0)
+			error("no map for *");
+		indir(m, l.store.u.ival, l.store.fmt, res);
+		res->store.comt = l.store.comt;
+		break;
+	case TREG:
+		indirreg(correg, l.store.u.reg, l.store.fmt, res);
+		res->store.comt = l.store.comt;
+		break;
+	case TCON:
+		*res = *l.store.u.con;
+		res->store.comt = l.store.comt;
+		break;
+	}
 }
 
 void
@@ -145,7 +175,7 @@ oframe(Node *n, Node *res)
 	while(*p && *p == '$')
 		p++;
 	lp = n->left;
-	if(localaddr(cormap, correg, p, lp->sym->name, &ival) < 0)
+	if(localaddr(cormap, acidregs, p, lp->sym->name, &ival) < 0)
 		error("colon: %r");
 		
 	res->store.u.ival = ival;
@@ -296,19 +326,24 @@ void
 oasgn(Node *n, Node *res)
 {
 	Node *lp, r;
+	Node aes;
 	Value *v;
 
 	lp = n->left;
 	switch(lp->op) {
 	case OINDM:
-		windir(cormap, lp->left, n->right, res);
+		expr(lp->left, &aes);
+		if(aes.type == TREG)
+			windirreg(correg, aes.store.u.reg, n->right, res);
+		else
+			windir(cormap, aes, n->right, res);
 		break;
 	case OINDC:
-		windir(symmap, lp->left, n->right, res);
+		expr(lp->left, &aes);
+		windir(symmap, aes, n->right, res);
 		break;
 	default:
-		chklval(lp);
-		v = lp->sym->v;
+		v = chklval(lp)->v;
 		expr(n->right, &r);
 		v->set = 1;
 		v->type = r.type;
@@ -871,8 +906,7 @@ oeinc(Node *n, Node *res)
 {
 	Value *v;
 
-	chklval(n->left);
-	v = n->left->sym->v;
+	v = chklval(n->left)->v;
 	res->op = OCONST;
 	res->type = v->type;
 	switch(v->type) {
@@ -899,8 +933,7 @@ opinc(Node *n, Node *res)
 {
 	Value *v;
 
-	chklval(n->left);
-	v = n->left->sym->v;
+	v = chklval(n->left)->v;
 	res->op = OCONST;
 	res->type = v->type;
 	res->store = v->store;
@@ -932,9 +965,7 @@ ocall(Node *n, Node *res)
 	res->type = TLIST;
 	res->store.u.l = 0;
 
-	chklval(n->left);
-	s = n->left->sym;
-
+	s = chklval(n->left);
 	if(n->builtin && !s->builtin){
 		error("no builtin %s", s->name);
 		return;
@@ -959,6 +990,12 @@ ofmt(Node *n, Node *res)
 }
 
 void
+ouplus(Node *n, Node *res)
+{
+	expr(n->left, res);
+}
+
+void
 owhat(Node *n, Node *res)
 {
 	res->op = OCONST;		/* Default return value */
@@ -1021,6 +1058,7 @@ initexpop(void)
 	expop[OFMT] = ofmt;
 	expop[OEVAL] = oeval;
 	expop[OWHAT] = owhat;
+	expop[OUPLUS] = ouplus;
 }
 
 void
@@ -1030,3 +1068,54 @@ initexpr(void)
 	initexpop();
 }
 
+int
+acidregsrw(Regs *r, char *name, ulong *u, int isr)
+{
+	Lsym *l;
+	Value *v;
+	Node *n;
+	ulong addr;
+	u32int u32;
+
+	if(!isr){
+		werrstr("cannot write registers");
+		return -1;
+	}
+	USED(r);
+	l = look(name);
+	if(l == nil){
+		werrstr("register %s not found", name);
+		return -1;
+	}
+	v = l->v;
+	switch(v->type){
+	default:
+		werrstr("*%s: bad type", name);
+		return -1;
+	case TREG:
+		if(correg == nil){
+			werrstr("*%s: register %s not mapped", name, v->store.u.reg);
+			return -1;
+		}
+		return rget(correg, v->store.u.reg, u);
+	case TCON:
+		n = v->store.u.con;
+		if(n->op != OCONST || n->type != TINT){
+			werrstr("*%s: bad register constant", name);
+			return -1;
+		}
+		*u = n->store.u.ival;
+		return 0;
+	case TINT:
+		if(cormap == nil){
+			werrstr("*%s: core not mapped", name);
+			return -1;
+		}
+		addr = v->store.u.ival;
+		/* XXX should use format to determine size */
+		if(get4(cormap, addr, &u32) < 0)
+			return -1;
+		*u = u32;
+		return 0;
+	}
+}