cl: compile async functions

cl/async.go

@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * 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 cl
+
+import (
+	"go/types"
+	"strings"
+
+	llssa "github.com/goplus/llgo/ssa"
+	"golang.org/x/tools/go/ssa"
+)
+
+// TODO(lijie): need more generics, shouldn't limit to async.Promise
+func promiseType(ty types.Type) (types.Type, bool) {
+	// ty is a generic type, so we need to check the package path and type name
+	if ptrTy, ok := ty.(*types.Pointer); ok {
+		ty = ptrTy.Elem()
+		if ty, ok := ty.(*types.Named); ok {
+			if ty.Obj().Pkg() == nil {
+				return nil, false
+			}
+			if ty.Obj().Pkg().Path() == "github.com/goplus/llgo/x/async" && ty.Obj().Name() == "Promise" {
+				return ty, true
+			}
+		}
+	}
+	return nil, false
+}
+
+// check function return async.Promise[T]
+// TODO(lijie): make it generic
+func isAsyncFunc(sig *types.Signature) bool {
+	r := sig.Results()
+	if r.Len() != 1 {
+		return false
+	}
+	ty := r.At(0).Type()
+	_, ok := promiseType(ty)
+	return ok
+}
+
+func (p *context) coAwait(b llssa.Builder, args []ssa.Value) llssa.Expr {
+	if !isAsyncFunc(b.Func.RawType().(*types.Signature)) {
+		panic("coAwait(promise *T) T: invalid context")
+	}
+	if len(args) == 1 {
+		// promise := p.compileValue(b, args[0])
+		b.Unreachable()
+		// return b.CoroutineAwait(promise)
+	}
+	panic("coAwait(promise *T) T: invalid arguments")
+}
+
+func (p *context) coSuspend(b llssa.Builder, final llssa.Expr) {
+	b.CoSuspend(b.AsyncToken(), final)
+}
+
+func (p *context) coDone(b llssa.Builder, args []ssa.Value) llssa.Expr {
+	if len(args) != 1 {
+		panic("coDone(promise *T): invalid arguments")
+	}
+	hdl := p.compileValue(b, args[0])
+	return b.CoDone(hdl)
+}
+
+func (p *context) coResume(b llssa.Builder, args []ssa.Value) {
+	if len(args) == 1 {
+		hdl := p.compileValue(b, args[0])
+		b.CoResume(hdl)
+	}
+}
+
+func (p *context) coReturn(b llssa.Builder, args []ssa.Value) {
+	cargs := make([]llssa.Expr, len(args))
+	for i, arg := range args {
+		cargs[i] = p.compileValue(b, arg)
+	}
+	b.CoReturn(cargs...)
+}
+
+func (p *context) coYield(b llssa.Builder, fn *ssa.Function, args []ssa.Value) {
+	typ := fn.Signature.Recv().Type()
+	mthds := p.goProg.MethodSets.MethodSet(typ)
+	// TODO(lijie): make llgo instruction callable (e.g. llgo.yield)
+	var setValue *ssa.Function
+	for i := 0; i < mthds.Len(); i++ {
+		m := mthds.At(i)
+		if ssaMthd := p.goProg.MethodValue(m); ssaMthd != nil {
+			if ssaMthd.Name() == "setValue" || strings.HasPrefix(ssaMthd.Name(), "setValue[") {
+				setValue = ssaMthd
+				break
+			}
+		}
+	}
+	if setValue == nil {
+		panic("coYield(): not found method setValue")
+	}
+	value := p.compileValue(b, args[1])
+	setValueFn, _, _ := p.funcOf(setValue)
+	b.CoYield(setValueFn, value)
+}
+
+func (p *context) coRun(b llssa.Builder, args []ssa.Value) {
+	panic("coRun(): not implemented")
+}