实现基础web服务器

vendor/github.com/bytedance/sonic/internal/jit/backend.go

@@ -0,0 +1,120 @@
+/*
+ * Copyright 2021 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 jit
+
+import (
+    `fmt`
+    `sync`
+    _ `unsafe`
+
+    `github.com/twitchyliquid64/golang-asm/asm/arch`
+    `github.com/twitchyliquid64/golang-asm/obj`
+    `github.com/twitchyliquid64/golang-asm/objabi`
+)
+
+type Backend struct {
+    Ctxt *obj.Link
+    Arch *arch.Arch
+    Head *obj.Prog
+    Tail *obj.Prog
+    Prog []*obj.Prog
+}
+
+var (
+    _progPool sync.Pool
+)
+
+//go:nosplit
+//go:linkname throw runtime.throw
+func throw(_ string)
+
+func newProg() *obj.Prog {
+    if val := _progPool.Get(); val == nil {
+        return new(obj.Prog)
+    } else {
+        return remProg(val.(*obj.Prog))
+    }
+}
+
+func remProg(p *obj.Prog) *obj.Prog {
+    *p = obj.Prog{}
+    return p
+}
+
+func newBackend(name string) (ret *Backend) {
+    ret      = new(Backend)
+    ret.Arch = arch.Set(name)
+    ret.Ctxt = newLinkContext(ret.Arch.LinkArch)
+    ret.Arch.Init(ret.Ctxt)
+    return
+}
+
+func newLinkContext(arch *obj.LinkArch) (ret *obj.Link) {
+    ret          = obj.Linknew(arch)
+    ret.Headtype = objabi.Hlinux
+    ret.DiagFunc = diagLinkContext
+    return
+}
+
+func diagLinkContext(str string, args ...interface{}) {
+    throw(fmt.Sprintf(str, args...))
+}
+
+func (self *Backend) New() (ret *obj.Prog) {
+    ret = newProg()
+    ret.Ctxt = self.Ctxt
+    self.Prog = append(self.Prog, ret)
+    return
+}
+
+func (self *Backend) Append(p *obj.Prog) {
+    if self.Head == nil {
+        self.Head = p
+        self.Tail = p
+    } else {
+        self.Tail.Link = p
+        self.Tail = p
+    }
+}
+
+func (self *Backend) Release() {
+    self.Arch = nil
+    self.Ctxt = nil
+
+    /* return all the progs into pool */
+    for _, p := range self.Prog {
+        _progPool.Put(p)
+    }
+
+    /* clear all the references */
+    self.Head = nil
+    self.Tail = nil
+    self.Prog = nil
+}
+
+func (self *Backend) Assemble() []byte {
+    var sym obj.LSym
+    var fnv obj.FuncInfo
+
+    /* construct the function */
+    sym.Func = &fnv
+    fnv.Text = self.Head
+
+    /* call the assembler */
+    self.Arch.Assemble(self.Ctxt, &sym, self.New)
+    return sym.P
+}