+static code_t* toreadwrite(code_t*in, code_t*middlepart)
+{
+ /* converts this:
+
+ [prefix code] [read instruction]
+
+ to this:
+
+ [prefix code] ([dup]) [read instruction] [setvar] [middlepart] [write instruction] [getvar]
+ */
+
+ if(in->next)
+ syntaxerror("internal error");
+
+ int temp = gettempvar();
+
+ /* chop off read instruction */
+ code_t*prefix = in;
+ code_t*r = in;
+ if(r->prev) {
+ prefix = r->prev;r->prev = 0;
+ prefix->next=0;
+ } else {
+ prefix = 0;
+ }
+
+ /* generate the write instruction, and maybe append a dup to the prefix code */
+ code_t* write = abc_nop(middlepart);
+ if(r->opcode == OPCODE_GETPROPERTY) {
+ write->opcode = OPCODE_SETPROPERTY;
+ multiname_t*m = (multiname_t*)r->data[0];
+ write->data[0] = multiname_clone(m);
+ if(m->type != QNAME)
+ syntaxerror("illegal lvalue: can't assign a value to this expression (not a qname)");
+ prefix = abc_dup(prefix); // we need the object, too
+ } else if(r->opcode == OPCODE_GETSLOT) {
+ write->opcode = OPCODE_SETSLOT;
+ write->data[0] = r->data[0];
+ prefix = abc_dup(prefix); // we need the object, too
+ } else if(r->opcode == OPCODE_GETLOCAL) {
+ write->opcode = OPCODE_SETLOCAL;
+ write->data[0] = r->data[0];
+ } else if(r->opcode == OPCODE_GETLOCAL_0) {
+ write->opcode = OPCODE_SETLOCAL_0;
+ } else if(r->opcode == OPCODE_GETLOCAL_1) {
+ write->opcode = OPCODE_SETLOCAL_1;
+ } else if(r->opcode == OPCODE_GETLOCAL_2) {
+ write->opcode = OPCODE_SETLOCAL_2;
+ } else if(r->opcode == OPCODE_GETLOCAL_3) {
+ write->opcode = OPCODE_SETLOCAL_3;
+ } else {
+ code_dump(r, 0, 0, "", stdout);
+ syntaxerror("illegal lvalue: can't assign a value to this expression");
+ }
+ code_t* c = prefix;
+ c = code_append(c, r);
+
+ c = abc_dup(c);
+ c = abc_setlocal(c, temp);
+ c = code_append(c, middlepart);
+ c = abc_getlocal(c, temp);
+ c = abc_kill(c, temp);
+
+ return c;
+}
+
+