/*
* n is call to interface method.
* generate res = n.
*/
func cgen_callinter(n *gc.Node, res *gc.Node, proc int) {
i := n.Left
if i.Op != gc.ODOTINTER {
gc.Fatal("cgen_callinter: not ODOTINTER %v", gc.Oconv(int(i.Op), 0))
}
f := i.Right // field
if f.Op != gc.ONAME {
gc.Fatal("cgen_callinter: not ONAME %v", gc.Oconv(int(f.Op), 0))
}
i = i.Left // interface
if i.Addable == 0 {
var tmpi gc.Node
gc.Tempname(&tmpi, i.Type)
cgen(i, &tmpi)
i = &tmpi
}
gc.Genlist(n.List) // assign the args
// i is now addable, prepare an indirected
// register to hold its address.
var nodi gc.Node
igen(i, &nodi, res) // REG = &inter
var nodsp gc.Node
gc.Nodindreg(&nodsp, gc.Types[gc.Tptr], x86.REG_SP)
nodsp.Xoffset = 0
if proc != 0 {
nodsp.Xoffset += 2 * int64(gc.Widthptr) // leave room for size & fn
}
nodi.Type = gc.Types[gc.Tptr]
nodi.Xoffset += int64(gc.Widthptr)
cgen(&nodi, &nodsp) // {0 or 8}(SP) = 4(REG) -- i.data
var nodo gc.Node
regalloc(&nodo, gc.Types[gc.Tptr], res)
nodi.Type = gc.Types[gc.Tptr]
nodi.Xoffset -= int64(gc.Widthptr)
cgen(&nodi, &nodo) // REG = 0(REG) -- i.tab
regfree(&nodi)
var nodr gc.Node
regalloc(&nodr, gc.Types[gc.Tptr], &nodo)
if n.Left.Xoffset == gc.BADWIDTH {
gc.Fatal("cgen_callinter: badwidth")
}
gc.Cgen_checknil(&nodo)
nodo.Op = gc.OINDREG
nodo.Xoffset = n.Left.Xoffset + 3*int64(gc.Widthptr) + 8
if proc == 0 {
// plain call: use direct c function pointer - more efficient
cgen(&nodo, &nodr) // REG = 20+offset(REG) -- i.tab->fun[f]
proc = 3
} else {
// go/defer. generate go func value.
gins(x86.ALEAL, &nodo, &nodr) // REG = &(20+offset(REG)) -- i.tab->fun[f]
}
nodr.Type = n.Left.Type
ginscall(&nodr, proc)
regfree(&nodr)
regfree(&nodo)
}
/*
* n is call to interface method.
* generate res = n.
*/
func cgen_callinter(n *gc.Node, res *gc.Node, proc int) {
i := n.Left
if i.Op != gc.ODOTINTER {
gc.Fatal("cgen_callinter: not ODOTINTER %v", gc.Oconv(int(i.Op), 0))
}
f := i.Right // field
if f.Op != gc.ONAME {
gc.Fatal("cgen_callinter: not ONAME %v", gc.Oconv(int(f.Op), 0))
}
i = i.Left // interface
// Release res register during genlist and cgen,
// which might have their own function calls.
r := -1
if res != nil && (res.Op == gc.OREGISTER || res.Op == gc.OINDREG) {
r = int(res.Val.U.Reg)
reg[r]--
}
if i.Addable == 0 {
var tmpi gc.Node
gc.Tempname(&tmpi, i.Type)
cgen(i, &tmpi)
i = &tmpi
}
gc.Genlist(n.List) // args
if r >= 0 {
reg[r]++
}
var nodr gc.Node
regalloc(&nodr, gc.Types[gc.Tptr], res)
var nodo gc.Node
regalloc(&nodo, gc.Types[gc.Tptr], &nodr)
nodo.Op = gc.OINDREG
agen(i, &nodr) // REG = &inter
var nodsp gc.Node
gc.Nodindreg(&nodsp, gc.Types[gc.Tptr], arm.REGSP)
nodsp.Xoffset = int64(gc.Widthptr)
if proc != 0 {
nodsp.Xoffset += 2 * int64(gc.Widthptr) // leave room for size & fn
}
nodo.Xoffset += int64(gc.Widthptr)
cgen(&nodo, &nodsp) // {4 or 12}(SP) = 4(REG) -- i.data
nodo.Xoffset -= int64(gc.Widthptr)
cgen(&nodo, &nodr) // REG = 0(REG) -- i.tab
gc.Cgen_checknil(&nodr) // in case offset is huge
nodo.Xoffset = n.Left.Xoffset + 3*int64(gc.Widthptr) + 8
if proc == 0 {
// plain call: use direct c function pointer - more efficient
cgen(&nodo, &nodr) // REG = 20+offset(REG) -- i.tab->fun[f]
nodr.Op = gc.OINDREG
proc = 3
} else {
// go/defer. generate go func value.
p := gins(arm.AMOVW, &nodo, &nodr)
p.From.Type = obj.TYPE_ADDR // REG = &(20+offset(REG)) -- i.tab->fun[f]
}
nodr.Type = n.Left.Type
ginscall(&nodr, proc)
regfree(&nodr)
regfree(&nodo)
}