Retro68/gcc/libgo/go/reflect/makefuncgo_386.go
2014-09-21 19:33:12 +02:00

144 lines
3.4 KiB
Go

// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// MakeFunc 386 implementation.
package reflect
import "unsafe"
// The assembler stub will pass a pointer to this structure. We
// assume that no parameters are passed in registers--that is, we do
// not support the -mregparm option. On return we will set the
// registers that might hold result values.
type i386Regs struct {
esp uint32
eax uint32 // Value to return in %eax.
st0 float64 // Value to return in %st(0).
sr bool // Set to true if hidden struct pointer.
sf bool // Set to true if returning float
}
// MakeFuncStubGo implements the 386 calling convention for MakeFunc.
// This should not be called. It is exported so that assembly code
// can call it.
func MakeFuncStubGo(regs *i386Regs, c *makeFuncImpl) {
ftyp := c.typ
// See if the result requires a struct. If it does, the first
// parameter is a pointer to the struct.
retStruct := false
retEmpty := false
switch len(ftyp.out) {
case 0:
retEmpty = true
case 1:
if ftyp.out[0].size == 0 {
retEmpty = true
} else {
switch ftyp.out[0].Kind() {
case Complex64, Complex128, Array, Interface, Slice, String, Struct:
retStruct = true
}
}
default:
size := uintptr(0)
for _, typ := range ftyp.out {
size += typ.size
}
if size == 0 {
retEmpty = true
} else {
retStruct = true
}
}
in := make([]Value, 0, len(ftyp.in))
ap := uintptr(regs.esp)
regs.sr = false
regs.sf = false
var retPtr unsafe.Pointer
if retStruct {
retPtr = *(*unsafe.Pointer)(unsafe.Pointer(ap))
ap += ptrSize
regs.sr = true
}
for _, rt := range ftyp.in {
ap = align(ap, ptrSize)
// We have to copy the argument onto the heap in case
// the function hangs on the reflect.Value we pass it.
p := unsafe_New(rt)
memmove(p, unsafe.Pointer(ap), rt.size)
v := Value{rt, p, flag(rt.Kind()<<flagKindShift) | flagIndir}
in = append(in, v)
ap += rt.size
}
// Call the real function.
out := c.call(in)
if len(out) != len(ftyp.out) {
panic("reflect: wrong return count from function created by MakeFunc")
}
for i, typ := range ftyp.out {
v := out[i]
if v.typ != typ {
panic("reflect: function created by MakeFunc using " + funcName(c.fn) +
" returned wrong type: have " +
out[i].typ.String() + " for " + typ.String())
}
if v.flag&flagRO != 0 {
panic("reflect: function created by MakeFunc using " + funcName(c.fn) +
" returned value obtained from unexported field")
}
}
if retEmpty {
return
}
if retStruct {
off := uintptr(0)
for i, typ := range ftyp.out {
v := out[i]
off = align(off, uintptr(typ.fieldAlign))
addr := unsafe.Pointer(uintptr(retPtr) + off)
if v.flag&flagIndir == 0 && (v.kind() == Ptr || v.kind() == UnsafePointer) {
storeIword(addr, iword(v.val), typ.size)
} else {
memmove(addr, v.val, typ.size)
}
off += typ.size
}
regs.eax = uint32(uintptr(retPtr))
return
}
if len(ftyp.out) != 1 {
panic("inconsistency")
}
v := out[0]
w := v.iword()
switch v.Kind() {
case Ptr, UnsafePointer:
regs.eax = uint32(uintptr(w))
case Float32:
regs.st0 = float64(*(*float32)(unsafe.Pointer(w)))
regs.sf = true
case Float64:
regs.st0 = *(*float64)(unsafe.Pointer(w))
regs.sf = true
default:
regs.eax = uint32(uintptr(loadIword(unsafe.Pointer(w), v.typ.size)))
}
}