GoToSocial/vendor/github.com/bytedance/sonic/loader/wrapper.go

186 lines
4.8 KiB
Go

/**
* Copyright 2023 ByteDance Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package loader
import (
`reflect`
`unsafe`
`github.com/bytedance/sonic/internal/abi`
`github.com/bytedance/sonic/internal/rt`
)
var _C_Redzone = []bool{false, false, false, false}
// CFunc is a function information for C func
type CFunc struct {
// C function name
Name string
// entry pc relative to entire text segment
EntryOff uint32
// function text size in bytes
TextSize uint32
// maximum stack depth of the function
MaxStack uintptr
// PC->SP delta lists of the function
Pcsp [][2]uint32
}
// GoC is the wrapper for Go calls to C
type GoC struct {
// CName is the name of corresponding C function
CName string
// CEntry points out where to store the entry address of corresponding C function.
// It won't be set if nil
CEntry *uintptr
// GoFunc is the POINTER of corresponding go stub function.
// It is used to generate Go-C ABI conversion wrapper and receive the wrapper's address
// eg. &func(a int, b int) int
// FOR
// int add(int a, int b)
// It won't be set if nil
GoFunc interface{}
}
// WrapGoC wraps C functions and loader it into Go stubs
func WrapGoC(text []byte, natives []CFunc, stubs []GoC, modulename string, filename string) {
funcs := make([]Func, len(natives))
// register C funcs
for i, f := range natives {
fn := Func{
Flag: FuncFlag_ASM,
EntryOff: f.EntryOff,
TextSize: f.TextSize,
Name: f.Name,
}
if len(f.Pcsp) != 0 {
fn.Pcsp = (*Pcdata)(unsafe.Pointer(&natives[i].Pcsp))
}
// NOTICE: always forbid async preempt
fn.PcUnsafePoint = &Pcdata{
{PC: f.TextSize, Val: PCDATA_UnsafePointUnsafe},
}
// NOTICE: always refer to first file
fn.Pcfile = &Pcdata{
{PC: f.TextSize, Val: 0},
}
// NOTICE: always refer to first line
fn.Pcline = &Pcdata{
{PC: f.TextSize, Val: 1},
}
// NOTICE: copystack need locals stackmap
fn.PcStackMapIndex = &Pcdata{
{PC: f.TextSize, Val: 0},
}
sm := rt.StackMapBuilder{}
sm.AddField(false)
fn.ArgsPointerMaps = sm.Build()
fn.LocalsPointerMaps = sm.Build()
funcs[i] = fn
}
rets := Load(text, funcs, modulename, []string{filename})
// got absolute entry address
native_entry := **(**uintptr)(unsafe.Pointer(&rets[0]))
// println("native_entry: ", native_entry)
wraps := make([]Func, 0, len(stubs))
wrapIds := make([]int, 0, len(stubs))
code := make([]byte, 0, len(wraps))
entryOff := uint32(0)
// register go wrappers
for i := range stubs {
for j := range natives {
if stubs[i].CName != natives[j].Name {
continue
}
// calculate corresponding C entry
pc := uintptr(native_entry + uintptr(natives[j].EntryOff))
if stubs[i].CEntry != nil {
*stubs[i].CEntry = pc
}
// no need to generate wrapper, continue next
if stubs[i].GoFunc == nil {
continue
}
// assemble wrapper codes
layout := abi.NewFunctionLayout(reflect.TypeOf(stubs[i].GoFunc).Elem())
frame := abi.NewFrame(&layout, _C_Redzone, true)
tcode := abi.CallC(pc, frame, natives[j].MaxStack)
code = append(code, tcode...)
size := uint32(len(tcode))
fn := Func{
Flag: FuncFlag_ASM,
ArgsSize: int32(layout.ArgSize()),
EntryOff: entryOff,
TextSize: size,
Name: stubs[i].CName + "_go",
}
// add check-stack and grow-stack texts' pcsp
fn.Pcsp = &Pcdata{
{PC: uint32(frame.StackCheckTextSize()), Val: 0},
{PC: size - uint32(frame.GrowStackTextSize()), Val: int32(frame.Size())},
{PC: size, Val: 0},
}
// NOTICE: always refer to first file
fn.Pcfile = &Pcdata{
{PC: size, Val: 0},
}
// NOTICE: always refer to first line
fn.Pcline = &Pcdata{
{PC: size, Val: 1},
}
// NOTICE: always forbid async preempt
fn.PcUnsafePoint = &Pcdata{
{PC: size, Val: PCDATA_UnsafePointUnsafe},
}
// register pointer stackmaps
fn.PcStackMapIndex = &Pcdata{
{PC: size, Val: 0},
}
fn.ArgsPointerMaps = frame.ArgPtrs()
fn.LocalsPointerMaps = frame.LocalPtrs()
entryOff += size
wraps = append(wraps, fn)
wrapIds = append(wrapIds, i)
}
}
gofuncs := Load(code, wraps, modulename+"/go", []string{filename+".go"})
// set go func value
for i := range gofuncs {
idx := wrapIds[i]
w := rt.UnpackEface(stubs[idx].GoFunc)
*(*Function)(w.Value) = gofuncs[i]
}
}