walkstate -> walkstmt
walktype -> walkexpr; stmts moved to walkstmt
walktype and friends have a final Node **init
argument that can have side effects appended,
making it more explicit when they do and do not happen.
this replaces the old global addtop and addtotop.
delete switch map and interface conversion cases
(dropped from the language months ago).
R=ken
OCL=31465
CL=31468
needed for heap allocation if variable escapes.
package main
func main(){
var i interface{} = 42;
switch v := i.(type) {
case int:
println(&v, v);
}
}
R=ken
OCL=31245
CL=31245
package main
func main() {
var x interface {} = 42;
switch x := x.(type) {
case int:
case foo:
}
}
before:
x.go:7: non-type case in type switch
x.go:7: inappropriate case for a type switch
now:
x.go:7: foo: undefined
R=ken
OCL=31221
CL=31221
this is not a user-visible change.
before, all interface values were
struct Itype {
Sigt *type;
Sigi *inter;
void *method[n];
}
struct Iface {
void *addr;
Itype *itype;
}
the itype is basically a vtable, but it's unnecessary
if the static type is interface{ }.
for interface values with static type empty, the
new representation is
struct Eface {
void *addr;
Sigt *type;
}
this complicates the code somewhat, but
it reduces the number of Itypes that
have to be computed and cached,
it opens up opportunities to avoid function
calls in a few common cases,
and it will make it possible to lay out
interface{} values at compile time,
which i think i'll need for the new reflection.
R=ken
OCL=28701
CL=29121
