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runtime, reflect: rewrite Go to FFI type conversion in Go

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As we move toward the Go 1.7 garbage collector, it's essential that all
    allocation of values that can contain Go pointers be done using the
    correct type descriptor.  That is simplest if we do all such allocation
    in Go code.  This rewrites the code that converts from a Go type to a
    libffi CIF into Go.
    
    Reviewed-on: https://go-review.googlesource.com/33353

From-SVN: r242578
This commit is contained in:
Ian Lance Taylor 2016-11-18 00:15:38 +00:00
parent f97db488a6
commit 5302cd0250
14 changed files with 475 additions and 342 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
gcc/go/gofrontend/MERGE
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@ -1,4 +1,4 @@
d9189ebc139ff739af956094626ccc5eb92c3091
bc5ad6d10092d6238495357468ee093f7caf39f9
The first line of this file holds the git revision number of the last
merge done from the gofrontend repository.

8
libgo/Makefile.am
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@ -1052,6 +1052,14 @@ runtime_internal_atomic_lo_check_GOCFLAGS = -fgo-compiling-runtime
runtime_internal_sys_lo_GOCFLAGS = -fgo-compiling-runtime
runtime_internal_sys_lo_check_GOCFLAGS = -fgo-compiling-runtime
# If libffi is supported (the normal case) use the ffi build tag for
# the runtime package.
if USE_LIBFFI
matchargs_runtime = --tag=libffi
else
matchargs_runtime =
endif
# At least for now, we need -static-libgo for this test, because
# otherwise we can't get the line numbers.
# Also use -fno-inline to get better results from the memory profiler.

5
libgo/Makefile.in
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@ -1154,6 +1154,11 @@ runtime_internal_atomic_lo_GOCFLAGS = -fgo-compiling-runtime
runtime_internal_atomic_lo_check_GOCFLAGS = -fgo-compiling-runtime
runtime_internal_sys_lo_GOCFLAGS = -fgo-compiling-runtime
runtime_internal_sys_lo_check_GOCFLAGS = -fgo-compiling-runtime
@USE_LIBFFI_FALSE@matchargs_runtime =
# If libffi is supported (the normal case) use the ffi build tag for
# the runtime package.
@USE_LIBFFI_TRUE@matchargs_runtime = --tag=libffi
# At least for now, we need -static-libgo for this test, because
# otherwise we can't get the line numbers.

16
libgo/configure vendored
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@ -665,6 +665,8 @@ LIBGO_IS_DARWIN_FALSE
LIBGO_IS_DARWIN_TRUE
go_include
LIBATOMIC
USE_LIBFFI_FALSE
USE_LIBFFI_TRUE
LIBFFIINCS
LIBFFI
nover_glibgo_toolexeclibdir
@ -11098,7 +11100,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
#line 11101 "configure"
#line 11106 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@ -13466,6 +13468,14 @@ $as_echo "#define USE_LIBFFI 1" >>confdefs.h
fi
if test "$with_liffi" != "no"; then
USE_LIBFFI_TRUE=
USE_LIBFFI_FALSE='#'
else
USE_LIBFFI_TRUE='#'
USE_LIBFFI_FALSE=
fi
# See if the user wants to configure without libatomic. This is useful if we are
# on an architecture for which libgo does not need an atomic support library and
@ -15596,6 +15606,10 @@ if test -z "${MAINTAINER_MODE_TRUE}" && test -z "${MAINTAINER_MODE_FALSE}"; then
as_fn_error "conditional \"MAINTAINER_MODE\" was never defined.
Usually this means the macro was only invoked conditionally." "$LINENO" 5
fi
if test -z "${USE_LIBFFI_TRUE}" && test -z "${USE_LIBFFI_FALSE}"; then
as_fn_error "conditional \"USE_LIBFFI\" was never defined.
Usually this means the macro was only invoked conditionally." "$LINENO" 5
fi
if test -z "${LIBGO_IS_DARWIN_TRUE}" && test -z "${LIBGO_IS_DARWIN_FALSE}"; then
as_fn_error "conditional \"LIBGO_IS_DARWIN\" was never defined.
Usually this means the macro was only invoked conditionally." "$LINENO" 5

1
libgo/configure.ac
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@ -121,6 +121,7 @@ if test "$with_libffi" != no; then
fi
AC_SUBST(LIBFFI)
AC_SUBST(LIBFFIINCS)
AM_CONDITIONAL(USE_LIBFFI, test "$with_liffi" != "no")
# See if the user wants to configure without libatomic. This is useful if we are
# on an architecture for which libgo does not need an atomic support library and

6
libgo/go/reflect/makefunc.go
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@ -63,7 +63,7 @@ func MakeFunc(typ Type, fn func(args []Value) (results []Value)) Value {
method: -1,
}
makeFuncFFI(ftyp, unsafe.Pointer(impl))
makeFuncFFI(makeCIF(ftyp), unsafe.Pointer(impl))
return Value{t, unsafe.Pointer(&impl), flag(Func) | flagIndir}
}
@ -102,7 +102,7 @@ func makeMethodValue(op string, v Value) Value {
rcvr: rcvr,
}
makeFuncFFI(ftyp, unsafe.Pointer(fv))
makeFuncFFI(makeCIF(ftyp), unsafe.Pointer(fv))
return Value{ft, unsafe.Pointer(&fv), v.flag&flagRO | flag(Func) | flagIndir}
}
@ -128,7 +128,7 @@ func makeValueMethod(v Value) Value {
rcvr: v,
}
makeFuncFFI(ftyp, unsafe.Pointer(impl))
makeFuncFFI(makeCIF(ftyp), unsafe.Pointer(impl))
return Value{t, unsafe.Pointer(&impl), v.flag&flagRO | flag(Func) | flagIndir}
}

5
libgo/go/reflect/makefunc_ffi.go
View File

@ -10,7 +10,10 @@ import (
// The makeFuncFFI function, written in C, fills in an FFI closure.
// It arranges for ffiCall to be invoked directly from FFI.
func makeFuncFFI(ftyp *funcType, impl unsafe.Pointer)
func makeFuncFFI(cif unsafe.Pointer, impl unsafe.Pointer)
// The makeCIF function, implemented in the runtime package, allocates a CIF.
func makeCIF(ft *funcType) unsafe.Pointer
// FFICallbackGo implements the Go side of the libffi callback.
// It is exported so that C code can call it.

15
libgo/go/reflect/makefunc_ffi_c.c
View File

@ -8,7 +8,7 @@
#ifdef USE_LIBFFI
#include "go-ffi.h"
#include "ffi.h"
#if FFI_GO_CLOSURES
#define USE_LIBFFI_CLOSURES
@ -18,7 +18,7 @@
/* Declare C functions with the names used to call from Go. */
void makeFuncFFI(const struct __go_func_type *ftyp, void *impl)
void makeFuncFFI(void *cif, void *impl)
__asm__ (GOSYM_PREFIX "reflect.makeFuncFFI");
#ifdef USE_LIBFFI_CLOSURES
@ -70,20 +70,15 @@ ffi_callback (ffi_cif* cif __attribute__ ((unused)), void *results,
/* Allocate an FFI closure and arrange to call ffi_callback. */
void
makeFuncFFI(const struct __go_func_type *ftyp, void *impl)
makeFuncFFI(void *cif, void *impl)
{
ffi_cif *cif;
cif = (ffi_cif *) __go_alloc (sizeof (ffi_cif));
__go_func_to_cif (ftyp, 0, 0, cif);
ffi_prep_go_closure(impl, cif, ffi_callback);
ffi_prep_go_closure(impl, (ffi_cif*)cif, ffi_callback);
}
#else /* !defined(USE_LIBFFI_CLOSURES) */
void
makeFuncFFI(const struct __go_func_type *ftyp __attribute__ ((unused)),
makeFuncFFI(void *cif __attribute__ ((unused)),
void *impl __attribute__ ((unused)))
{
runtime_panicstring ("libgo built without FFI does not support "

315
libgo/go/runtime/ffi.go Normal file
View File

@ -0,0 +1,315 @@
// Copyright 2009 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.
// Only build this file if libffi is supported.
// +build libffi
package runtime
import "unsafe"
// This file contains the code that converts a Go type to an FFI type.
// This has to be written in Go because it allocates memory in the Go heap.
// C functions to return pointers to libffi variables.
func ffi_type_pointer() *__ffi_type
func ffi_type_sint8() *__ffi_type
func ffi_type_sint16() *__ffi_type
func ffi_type_sint32() *__ffi_type
func ffi_type_sint64() *__ffi_type
func ffi_type_uint8() *__ffi_type
func ffi_type_uint16() *__ffi_type
func ffi_type_uint32() *__ffi_type
func ffi_type_uint64() *__ffi_type
func ffi_type_float() *__ffi_type
func ffi_type_double() *__ffi_type
func ffi_supports_complex() bool
func ffi_type_complex_float() *__ffi_type
func ffi_type_complex_double() *__ffi_type
func ffi_type_void() *__ffi_type
// C functions defined in libffi.
//extern ffi_prep_cif
func ffi_prep_cif(*_ffi_cif, _ffi_abi, uint32, *__ffi_type, **__ffi_type) _ffi_status
// ffiFuncToCIF is called from C code.
//go:linkname ffiFuncToCIF runtime.ffiFuncToCIF
// ffiFuncToCIF builds an _ffi_cif struct for function described by ft.
func ffiFuncToCIF(ft *functype, isInterface bool, isMethod bool, cif *_ffi_cif) {
nparams := len(ft.in)
nargs := nparams
if isInterface {
nargs++
}
args := make([]*__ffi_type, nargs)
i := 0
off := 0
if isInterface {
args[0] = ffi_type_pointer()
off = 1
} else if isMethod {
args[0] = ffi_type_pointer()
i = 1
}
for ; i < nparams; i++ {
args[i+off] = typeToFFI(ft.in[i])
}
rettype := funcReturnFFI(ft)
var pargs **__ffi_type
if len(args) > 0 {
pargs = &args[0]
}
status := ffi_prep_cif(cif, _FFI_DEFAULT_ABI, uint32(nargs), rettype, pargs)
if status != _FFI_OK {
throw("ffi_prep_cif failed")
}
}
// funcReturnFFI returns the FFI definition of the return type of ft.
func funcReturnFFI(ft *functype) *__ffi_type {
c := len(ft.out)
if c == 0 {
return ffi_type_void()
}
// Compile a function that returns a zero-sized value as
// though it returns void. This works around a problem in
// libffi: it can't represent a zero-sized value.
var size uintptr
for _, v := range ft.out {
size += v.size
}
if size == 0 {
return ffi_type_void()
}
if c == 1 {
return typeToFFI(ft.out[0])
}
elements := make([]*__ffi_type, c+1)
for i, v := range ft.out {
elements[i] = typeToFFI(v)
}
elements[c] = nil
return &__ffi_type{
_type: _FFI_TYPE_STRUCT,
elements: &elements[0],
}
}
// typeToFFI returns the __ffi_type for a Go type.
func typeToFFI(typ *_type) *__ffi_type {
switch typ.kind & kindMask {
case kindBool:
switch unsafe.Sizeof(false) {
case 1:
return ffi_type_uint8()
case 4:
return ffi_type_uint32()
default:
throw("bad bool size")
return nil
}
case kindInt:
return intToFFI()
case kindInt8:
return ffi_type_sint8()
case kindInt16:
return ffi_type_sint16()
case kindInt32:
return ffi_type_sint32()
case kindInt64:
return ffi_type_sint64()
case kindUint:
switch unsafe.Sizeof(uint(0)) {
case 4:
return ffi_type_uint32()
case 8:
return ffi_type_uint64()
default:
throw("bad uint size")
return nil
}
case kindUint8:
return ffi_type_uint8()
case kindUint16:
return ffi_type_uint16()
case kindUint32:
return ffi_type_uint32()
case kindUint64:
return ffi_type_uint64()
case kindUintptr:
switch unsafe.Sizeof(uintptr(0)) {
case 4:
return ffi_type_uint32()
case 8:
return ffi_type_uint64()
default:
throw("bad uinptr size")
return nil
}
case kindFloat32:
return ffi_type_float()
case kindFloat64:
return ffi_type_double()
case kindComplex64:
if ffi_supports_complex() {
return ffi_type_complex_float()
} else {
return complexToFFI(ffi_type_float())
}
case kindComplex128:
if ffi_supports_complex() {
return ffi_type_complex_double()
} else {
return complexToFFI(ffi_type_double())
}
case kindArray:
return arrayToFFI((*arraytype)(unsafe.Pointer(typ)))
case kindChan, kindFunc, kindMap, kindPtr, kindUnsafePointer:
// These types are always simple pointers, and for FFI
// purposes nothing else matters.
return ffi_type_pointer()
case kindInterface:
return interfaceToFFI()
case kindSlice:
return sliceToFFI((*slicetype)(unsafe.Pointer(typ)))
case kindString:
return stringToFFI()
case kindStruct:
return structToFFI((*structtype)(unsafe.Pointer(typ)))
default:
throw("unknown type kind")
return nil
}
}
// interfaceToFFI returns an ffi_type for a Go interface type.
// This is used for both empty and non-empty interface types.
func interfaceToFFI() *__ffi_type {
elements := make([]*__ffi_type, 3)
elements[0] = ffi_type_pointer()
elements[1] = elements[0]
elements[2] = nil
return &__ffi_type{
_type: _FFI_TYPE_STRUCT,
elements: &elements[0],
}
}
// stringToFFI returns an ffi_type for a Go string type.
func stringToFFI() *__ffi_type {
elements := make([]*__ffi_type, 3)
elements[0] = ffi_type_pointer()
elements[1] = intToFFI()
elements[2] = nil
return &__ffi_type{
_type: _FFI_TYPE_STRUCT,
elements: &elements[0],
}
}
// structToFFI returns an ffi_type for a Go struct type.
func structToFFI(typ *structtype) *__ffi_type {
c := len(typ.fields)
if c == 0 {
return emptyStructToFFI()
}
fields := make([]*__ffi_type, c+1)
for i, v := range typ.fields {
fields[i] = typeToFFI(v.typ)
}
fields[c] = nil
return &__ffi_type{
_type: _FFI_TYPE_STRUCT,
elements: &fields[0],
}
}
// sliceToFFI returns an ffi_type for a Go slice type.
func sliceToFFI(typ *slicetype) *__ffi_type {
elements := make([]*__ffi_type, 4)
elements[0] = ffi_type_pointer()
elements[1] = intToFFI()
elements[2] = elements[1]
elements[3] = nil
return &__ffi_type{
_type: _FFI_TYPE_STRUCT,
elements: &elements[0],
}
}
// complexToFFI returns an ffi_type for a Go complex type.
// This is only used if libffi does not support complex types internally
// for this target.
func complexToFFI(ffiFloatType *__ffi_type) *__ffi_type {
elements := make([]*__ffi_type, 3)
elements[0] = ffiFloatType
elements[1] = ffiFloatType
elements[2] = nil
return &__ffi_type{
_type: _FFI_TYPE_STRUCT,
elements: &elements[0],
}
}
// arrayToFFI returns an ffi_type for a Go array type.
func arrayToFFI(typ *arraytype) *__ffi_type {
if typ.len == 0 {
return emptyStructToFFI()
}
elements := make([]*__ffi_type, typ.len+1)
et := typeToFFI(typ.elem)
for i := uintptr(0); i < typ.len; i++ {
elements[i] = et
}
elements[typ.len] = nil
return &__ffi_type{
_type: _FFI_TYPE_STRUCT,
elements: &elements[0],
}
}
// intToFFI returns an ffi_type for the Go int type.
func intToFFI() *__ffi_type {
switch unsafe.Sizeof(0) {
case 4:
return ffi_type_sint32()
case 8:
return ffi_type_sint64()
default:
throw("bad int size")
return nil
}
}
// emptyStructToFFI returns an ffi_type for an empty struct.
// The libffi library won't accept a struct with no fields.
func emptyStructToFFI() *__ffi_type {
elements := make([]*__ffi_type, 2)
elements[0] = ffi_type_void()
elements[1] = nil
return &__ffi_type{
_type: _FFI_TYPE_STRUCT,
elements: &elements[0],
}
}
//go:linkname makeCIF reflect.makeCIF
// makeCIF is used by the reflect package to allocate a CIF.
func makeCIF(ft *functype) *_ffi_cif {
cif := new(_ffi_cif)
ffiFuncToCIF(ft, false, false, cif)
return cif
}

1
libgo/mkrsysinfo.sh
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@ -18,6 +18,7 @@ echo 'package runtime' > ${OUT}
# will all have a leading underscore.
grep -v '^// ' gen-sysinfo.go | \
grep -v '^func' | \
grep -v '^var ' | \
grep -v '^type _timeval ' | \
grep -v '^type _timespec_t ' | \
grep -v '^type _timespec ' | \

411
libgo/runtime/go-ffi.c
View File

@ -1,357 +1,152 @@
/* go-ffi.c -- convert Go type description to libffi.
/* go-ffi.c -- libffi support functions.
Copyright 2009 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. */
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include "runtime.h"
#include "go-alloc.h"
#include "go-assert.h"
#include "go-type.h"
#ifdef USE_LIBFFI
#include "ffi.h"
/* The functions in this file are only called from reflect_call and
reflect.ffi. As these functions call libffi functions, which will
be compiled without -fsplit-stack, they will always run with a
large stack. */
/* The functions in this file are called by the Go runtime code to get
the libffi type values. */
static ffi_type *go_array_to_ffi (const struct __go_array_type *)
__attribute__ ((no_split_stack));
static ffi_type *go_slice_to_ffi (const struct __go_slice_type *)
__attribute__ ((no_split_stack));
static ffi_type *go_struct_to_ffi (const struct __go_struct_type *)
__attribute__ ((no_split_stack));
static ffi_type *go_string_to_ffi (void) __attribute__ ((no_split_stack));
static ffi_type *go_interface_to_ffi (void) __attribute__ ((no_split_stack));
static ffi_type *go_type_to_ffi (const struct __go_type_descriptor *)
__attribute__ ((no_split_stack));
static ffi_type *go_func_return_ffi (const struct __go_func_type *)
__attribute__ ((no_split_stack));
ffi_type *go_ffi_type_pointer(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_pointer(void) __asm__ ("runtime.ffi_type_pointer");
ffi_type *go_ffi_type_sint8(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_sint8(void) __asm__ ("runtime.ffi_type_sint8");
ffi_type *go_ffi_type_sint16(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_sint16(void) __asm__ ("runtime.ffi_type_sint16");
ffi_type *go_ffi_type_sint32(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_sint32(void) __asm__ ("runtime.ffi_type_sint32");
ffi_type *go_ffi_type_sint64(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_sint64(void) __asm__ ("runtime.ffi_type_sint64");
ffi_type *go_ffi_type_uint8(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_uint8(void) __asm__ ("runtime.ffi_type_uint8");
ffi_type *go_ffi_type_uint16(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_uint16(void) __asm__ ("runtime.ffi_type_uint16");
ffi_type *go_ffi_type_uint32(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_uint32(void) __asm__ ("runtime.ffi_type_uint32");
ffi_type *go_ffi_type_uint64(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_uint64(void) __asm__ ("runtime.ffi_type_uint64");
ffi_type *go_ffi_type_float(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_float(void) __asm__ ("runtime.ffi_type_float");
ffi_type *go_ffi_type_double(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_double(void) __asm__ ("runtime.ffi_type_double");
ffi_type *go_ffi_type_complex_float(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_complex_float(void) __asm__ ("runtime.ffi_type_complex_float");
ffi_type *go_ffi_type_complex_double(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_complex_double(void) __asm__ ("runtime.ffi_type_complex_double");
ffi_type *go_ffi_type_void(void) __attribute__ ((no_split_stack));
ffi_type *go_ffi_type_void(void) __asm__ ("runtime.ffi_type_void");
/* Return an ffi_type for a Go array type. The libffi library does
not have any builtin support for passing arrays as values. We work
around this by pretending that the array is a struct. */
_Bool go_ffi_supports_complex(void) __attribute__ ((no_split_stack));
_Bool go_ffi_supports_complex(void) __asm__ ("runtime.ffi_supports_complex");
static ffi_type *
go_array_to_ffi (const struct __go_array_type *descriptor)
ffi_type *
go_ffi_type_pointer(void)
{
ffi_type *ret;
uintptr_t len;
ffi_type *element;
uintptr_t i;
ret = (ffi_type *) __go_alloc (sizeof (ffi_type));
ret->type = FFI_TYPE_STRUCT;
len = descriptor->__len;
if (len == 0)
{
/* The libffi library won't accept an empty struct. */
ret->elements = (ffi_type **) __go_alloc (2 * sizeof (ffi_type *));
ret->elements[0] = &ffi_type_void;
ret->elements[1] = NULL;
return ret;
}
ret->elements = (ffi_type **) __go_alloc ((len + 1) * sizeof (ffi_type *));
element = go_type_to_ffi (descriptor->__element_type);
for (i = 0; i < len; ++i)
ret->elements[i] = element;
ret->elements[len] = NULL;
return ret;
return &ffi_type_pointer;
}
/* Return an ffi_type for a Go slice type. This describes the
__go_open_array type defines in array.h. */
static ffi_type *
go_slice_to_ffi (
const struct __go_slice_type *descriptor __attribute__ ((unused)))
ffi_type *
go_ffi_type_sint8(void)
{
ffi_type *ret;
ffi_type *ffi_intgo;
ret = (ffi_type *) __go_alloc (sizeof (ffi_type));
ret->type = FFI_TYPE_STRUCT;
ret->elements = (ffi_type **) __go_alloc (4 * sizeof (ffi_type *));
ret->elements[0] = &ffi_type_pointer;
ffi_intgo = sizeof (intgo) == 4 ? &ffi_type_sint32 : &ffi_type_sint64;
ret->elements[1] = ffi_intgo;
ret->elements[2] = ffi_intgo;
ret->elements[3] = NULL;
return ret;
return &ffi_type_sint8;
}
/* Return an ffi_type for a Go struct type. */
static ffi_type *
go_struct_to_ffi (const struct __go_struct_type *descriptor)
ffi_type *
go_ffi_type_sint16(void)
{
ffi_type *ret;
int field_count;
const struct __go_struct_field *fields;
int i;
field_count = descriptor->__fields.__count;
ret = (ffi_type *) __go_alloc (sizeof (ffi_type));
ret->type = FFI_TYPE_STRUCT;
if (field_count == 0)
{
/* The libffi library won't accept an empty struct. */
ret->elements = (ffi_type **) __go_alloc (2 * sizeof (ffi_type *));
ret->elements[0] = &ffi_type_void;
ret->elements[1] = NULL;
return ret;
}
fields = (const struct __go_struct_field *) descriptor->__fields.__values;
ret->elements = (ffi_type **) __go_alloc ((field_count + 1)
* sizeof (ffi_type *));
for (i = 0; i < field_count; ++i)
ret->elements[i] = go_type_to_ffi (fields[i].__type);
ret->elements[field_count] = NULL;
return ret;
return &ffi_type_sint16;
}
/* Return an ffi_type for a Go string type. This describes the String
struct. */
static ffi_type *
go_string_to_ffi (void)
ffi_type *
go_ffi_type_sint32(void)
{
ffi_type *ret;
ffi_type *ffi_intgo;
ret = (ffi_type *) __go_alloc (sizeof (ffi_type));
ret->type = FFI_TYPE_STRUCT;
ret->elements = (ffi_type **) __go_alloc (3 * sizeof (ffi_type *));
ret->elements[0] = &ffi_type_pointer;
ffi_intgo = sizeof (intgo) == 4 ? &ffi_type_sint32 : &ffi_type_sint64;
ret->elements[1] = ffi_intgo;
ret->elements[2] = NULL;
return ret;
return &ffi_type_sint32;
}
/* Return an ffi_type for a Go interface type. This describes the
__go_interface and __go_empty_interface structs. */
static ffi_type *
go_interface_to_ffi (void)
ffi_type *
go_ffi_type_sint64(void)
{
ffi_type *ret;
ret = (ffi_type *) __go_alloc (sizeof (ffi_type));
ret->type = FFI_TYPE_STRUCT;
ret->elements = (ffi_type **) __go_alloc (3 * sizeof (ffi_type *));
ret->elements[0] = &ffi_type_pointer;
ret->elements[1] = &ffi_type_pointer;
ret->elements[2] = NULL;
return ret;
return &ffi_type_sint64;
}
#ifndef FFI_TARGET_HAS_COMPLEX_TYPE
/* If libffi hasn't been updated for this target to support complex,
pretend complex is a structure. Warning: This does not work for
all ABIs. Eventually libffi should be updated for all targets
and this should go away. */
static ffi_type *go_complex_to_ffi (ffi_type *)
__attribute__ ((no_split_stack));
static ffi_type *
go_complex_to_ffi (ffi_type *float_type)
ffi_type *
go_ffi_type_uint8(void)
{
ffi_type *ret;
ret = (ffi_type *) __go_alloc (sizeof (ffi_type));
ret->type = FFI_TYPE_STRUCT;
ret->elements = (ffi_type **) __go_alloc (3 * sizeof (ffi_type *));
ret->elements[0] = float_type;
ret->elements[1] = float_type;
ret->elements[2] = NULL;
return ret;
}
#endif
/* Return an ffi_type for a type described by a
__go_type_descriptor. */
static ffi_type *
go_type_to_ffi (const struct __go_type_descriptor *descriptor)
{
switch (descriptor->__code & GO_CODE_MASK)
{
case GO_BOOL:
if (sizeof (_Bool) == 1)
return &ffi_type_uint8;
else if (sizeof (_Bool) == sizeof (int))
return &ffi_type_uint;
abort ();
case GO_FLOAT32:
if (sizeof (float) == 4)
return &ffi_type_float;
abort ();
case GO_FLOAT64:
if (sizeof (double) == 8)
return &ffi_type_double;
abort ();
case GO_COMPLEX64:
if (sizeof (float) == 4)
{
#ifdef FFI_TARGET_HAS_COMPLEX_TYPE
return &ffi_type_complex_float;
#else
return go_complex_to_ffi (&ffi_type_float);
#endif
}
abort ();
case GO_COMPLEX128:
if (sizeof (double) == 8)
{
#ifdef FFI_TARGET_HAS_COMPLEX_TYPE
return &ffi_type_complex_double;
#else
return go_complex_to_ffi (&ffi_type_double);
#endif
}
abort ();
case GO_INT16:
return &ffi_type_sint16;
case GO_INT32:
return &ffi_type_sint32;
case GO_INT64:
return &ffi_type_sint64;
case GO_INT8:
return &ffi_type_sint8;
case GO_INT:
return sizeof (intgo) == 4 ? &ffi_type_sint32 : &ffi_type_sint64;
case GO_UINT16:
return &ffi_type_uint16;
case GO_UINT32:
return &ffi_type_uint32;
case GO_UINT64:
return &ffi_type_uint64;
case GO_UINT8:
return &ffi_type_uint8;
case GO_UINT:
return sizeof (uintgo) == 4 ? &ffi_type_uint32 : &ffi_type_uint64;
case GO_UINTPTR:
if (sizeof (void *) == 2)
}
ffi_type *
go_ffi_type_uint16(void)
{
return &ffi_type_uint16;
else if (sizeof (void *) == 4)
}
ffi_type *
go_ffi_type_uint32(void)
{
return &ffi_type_uint32;
else if (sizeof (void *) == 8)
}
ffi_type *
go_ffi_type_uint64(void)
{
return &ffi_type_uint64;
abort ();
case GO_ARRAY:
return go_array_to_ffi ((const struct __go_array_type *) descriptor);
case GO_SLICE:
return go_slice_to_ffi ((const struct __go_slice_type *) descriptor);
case GO_STRUCT:
return go_struct_to_ffi ((const struct __go_struct_type *) descriptor);
case GO_STRING:
return go_string_to_ffi ();
case GO_INTERFACE:
return go_interface_to_ffi ();
case GO_CHAN:
case GO_FUNC:
case GO_MAP:
case GO_PTR:
case GO_UNSAFE_POINTER:
/* These types are always pointers, and for FFI purposes nothing
else matters. */
return &ffi_type_pointer;
default:
abort ();
}
}
/* Return the return type for a function, given the number of out
parameters and their types. */
static ffi_type *
go_func_return_ffi (const struct __go_func_type *func)
ffi_type *
go_ffi_type_float(void)
{
int count;
const struct __go_type_descriptor **types;
ffi_type *ret;
int i;
count = func->__out.__count;
if (count == 0)
return &ffi_type_void;
types = (const struct __go_type_descriptor **) func->__out.__values;
// We compile a function that returns a zero-sized value as though
// it returns void. This works around a problem in libffi: it can't
// represent a zero-sized value.
for (i = 0; i < count; ++i)
{
if (types[i]->__size > 0)
break;
}
if (i == count)
return &ffi_type_void;
if (count == 1)
return go_type_to_ffi (types[0]);
ret = (ffi_type *) __go_alloc (sizeof (ffi_type));
ret->type = FFI_TYPE_STRUCT;
ret->elements = (ffi_type **) __go_alloc ((count + 1) * sizeof (ffi_type *));
for (i = 0; i < count; ++i)
ret->elements[i] = go_type_to_ffi (types[i]);
ret->elements[count] = NULL;
return ret;
return &ffi_type_float;
}
/* Build an ffi_cif structure for a function described by a
__go_func_type structure. */
void
__go_func_to_cif (const struct __go_func_type *func, _Bool is_interface,
_Bool is_method, ffi_cif *cif)
ffi_type *
go_ffi_type_double(void)
{
int num_params;
const struct __go_type_descriptor **in_types;
size_t num_args;
ffi_type **args;
int off;
int i;
ffi_type *rettype;
ffi_status status;
return &ffi_type_double;
}
num_params = func->__in.__count;
in_types = ((const struct __go_type_descriptor **)
func->__in.__values);
_Bool
go_ffi_supports_complex(void)
{
#ifdef FFI_TARGET_HAS_COMPLEX_TYPE
return true;
#else
return false;
#endif
}
num_args = num_params + (is_interface ? 1 : 0);
args = (ffi_type **) __go_alloc (num_args * sizeof (ffi_type *));
i = 0;
off = 0;
if (is_interface)
{
args[0] = &ffi_type_pointer;
off = 1;
}
else if (is_method)
{
args[0] = &ffi_type_pointer;
i = 1;
}
for (; i < num_params; ++i)
args[i + off] = go_type_to_ffi (in_types[i]);
ffi_type *
go_ffi_type_complex_float(void)
{
#ifdef FFI_TARGET_HAS_COMPLEX_TYPE
return &ffi_type_complex_float;
#else
abort();
#endif
}
rettype = go_func_return_ffi (func);
ffi_type *
go_ffi_type_complex_double(void)
{
#ifdef FFI_TARGET_HAS_COMPLEX_TYPE
return &ffi_type_complex_double;
#else
abort();
#endif
}
status = ffi_prep_cif (cif, FFI_DEFAULT_ABI, num_args, rettype, args);
__go_assert (status == FFI_OK);
ffi_type *
go_ffi_type_void(void)
{
return &ffi_type_void;
}
#endif /* defined(USE_LIBFFI) */

16
libgo/runtime/go-ffi.h
View File

@ -1,16 +0,0 @@
/* go-ffi.c -- convert Go type description to libffi.
Copyright 2014 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. */
#include "config.h"
#include "go-type.h"
#ifdef USE_LIBFFI
#include "ffi.h"
void __go_func_to_cif (const struct __go_func_type *, _Bool, _Bool, ffi_cif *);
#endif

12
libgo/runtime/go-reflect-call.c
View File

@ -12,7 +12,10 @@
#include "go-alloc.h"
#include "go-assert.h"
#include "go-type.h"
#include "go-ffi.h"
#ifdef USE_LIBFFI
#include "ffi.h"
#endif
#if defined(USE_LIBFFI) && FFI_GO_CLOSURES
@ -197,6 +200,11 @@ go_set_results (const struct __go_func_type *func, unsigned char *call_result,
}
}
/* The code that converts the Go type to an FFI type is written in Go,
so that it can allocate Go heap memory. */
extern void ffiFuncToCIF(const struct __go_func_type*, _Bool, _Bool, ffi_cif*)
__asm__ ("runtime.ffiFuncToCIF");
/* Call a function. The type of the function is FUNC_TYPE, and the
closure is FUNC_VAL. PARAMS is an array of parameter addresses.
RESULTS is an array of result addresses.
@ -218,7 +226,7 @@ reflect_call (const struct __go_func_type *func_type, FuncVal *func_val,
unsigned char *call_result;
__go_assert ((func_type->__common.__code & GO_CODE_MASK) == GO_FUNC);
__go_func_to_cif (func_type, is_interface, is_method, &cif);
ffiFuncToCIF (func_type, is_interface, is_method, &cif);
call_result = (unsigned char *) malloc (go_results_size (func_type));

4
libgo/sysinfo.c
View File

@ -163,6 +163,10 @@
#include <port.h>
#endif
#ifdef USE_LIBFFI
#include "ffi.h"
#endif
/* Constants that may only be defined as expressions on some systems,
expressions too complex for -fdump-go-spec to handle. These are
handled specially below. */