Merge pull request #666 from cpunion/async-functions

Async functions

cl/_testdata/async/in.go

@@ -0,0 +1,27 @@
+package async
+
+import (
+	"github.com/goplus/llgo/x/async"
+)
+
+func GenInts() (co *async.Promise[int]) {
+	co.Yield(1)
+	co.Yield(2)
+	co.Yield(3)
+	return
+}
+
+func WrapGenInts() *async.Promise[int] {
+	return GenInts()
+}
+
+func UseGenInts() int {
+	co := WrapGenInts()
+	r := 0
+	for !co.Done() {
+		v := co.Value()
+		r += v
+		co.Next()
+	}
+	return r
+}

cl/_testdata/async/out.ll

@@ -0,0 +1,201 @@
+; ModuleID = 'async'
+source_filename = "async"
+
+%"github.com/goplus/llgo/x/async.Promise[int]" = type { ptr, i64 }
+
+@"async.init$guard" = global i1 false, align 1
+
+define ptr @async.GenInts() presplitcoroutine {
+entry:
+  %id = call token @llvm.coro.id(i32 0, ptr null, ptr null, ptr null)
+  %frame.size = call i64 @llvm.coro.size.i64()
+  %alloc.size = add i64 16, %frame.size
+  %promise = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 %alloc.size)
+  %need.dyn.alloc = call i1 @llvm.coro.alloc(token %id)
+  br i1 %need.dyn.alloc, label %alloc, label %_llgo_5
+
+alloc:                                            ; preds = %entry
+  %0 = getelementptr ptr, ptr %promise, i64 16
+  br label %_llgo_5
+
+clean:                                            ; preds = %_llgo_8, %_llgo_7, %_llgo_6, %_llgo_5
+  %1 = call ptr @llvm.coro.free(token %id, ptr %hdl)
+  br label %suspend
+
+suspend:                                          ; preds = %_llgo_8, %_llgo_7, %_llgo_6, %_llgo_5, %clean
+  %2 = call i1 @llvm.coro.end(ptr %hdl, i1 false, token none)
+  ret ptr %promise
+
+trap:                                             ; preds = %_llgo_8
+  call void @llvm.trap()
+  unreachable
+
+_llgo_5:                                          ; preds = %alloc, %entry
+  %frame = phi ptr [ null, %entry ], [ %0, %alloc ]
+  %hdl = call ptr @llvm.coro.begin(token %id, ptr %frame)
+  store ptr %hdl, ptr %promise, align 8
+  call void @"github.com/goplus/llgo/x/async.(*Promise).setValue[int]"(ptr %promise, i64 1)
+  %3 = call i8 @llvm.coro.suspend(token %id, i1 false)
+  switch i8 %3, label %suspend [
+    i8 0, label %_llgo_6
+    i8 1, label %clean
+  ]
+
+_llgo_6:                                          ; preds = %_llgo_5
+  call void @"github.com/goplus/llgo/x/async.(*Promise).setValue[int]"(ptr %promise, i64 2)
+  %4 = call i8 @llvm.coro.suspend(token %id, i1 false)
+  switch i8 %4, label %suspend [
+    i8 0, label %_llgo_7
+    i8 1, label %clean
+  ]
+
+_llgo_7:                                          ; preds = %_llgo_6
+  call void @"github.com/goplus/llgo/x/async.(*Promise).setValue[int]"(ptr %promise, i64 3)
+  %5 = call i8 @llvm.coro.suspend(token %id, i1 false)
+  switch i8 %5, label %suspend [
+    i8 0, label %_llgo_8
+    i8 1, label %clean
+  ]
+
+_llgo_8:                                          ; preds = %_llgo_7
+  %6 = call i8 @llvm.coro.suspend(token %id, i1 true)
+  switch i8 %6, label %suspend [
+    i8 0, label %trap
+    i8 1, label %clean
+  ]
+}
+
+define i64 @async.UseGenInts() {
+_llgo_0:
+  %0 = call ptr @async.WrapGenInts()
+  br label %_llgo_3
+
+_llgo_1:                                          ; preds = %_llgo_3
+  %1 = call i64 @"github.com/goplus/llgo/x/async.(*Promise).Value[int]"(ptr %0)
+  %2 = add i64 %3, %1
+  call void @"github.com/goplus/llgo/x/async.(*Promise).Next[int]"(ptr %0)
+  br label %_llgo_3
+
+_llgo_2:                                          ; preds = %_llgo_3
+  ret i64 %3
+
+_llgo_3:                                          ; preds = %_llgo_1, %_llgo_0
+  %3 = phi i64 [ 0, %_llgo_0 ], [ %2, %_llgo_1 ]
+  %4 = call i1 @"github.com/goplus/llgo/x/async.(*Promise).Done[int]"(ptr %0)
+  br i1 %4, label %_llgo_2, label %_llgo_1
+}
+
+define ptr @async.WrapGenInts() presplitcoroutine {
+entry:
+  %id = call token @llvm.coro.id(i32 0, ptr null, ptr null, ptr null)
+  %frame.size = call i64 @llvm.coro.size.i64()
+  %alloc.size = add i64 16, %frame.size
+  %promise = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 %alloc.size)
+  %need.dyn.alloc = call i1 @llvm.coro.alloc(token %id)
+  br i1 %need.dyn.alloc, label %alloc, label %_llgo_5
+
+alloc:                                            ; preds = %entry
+  %0 = getelementptr ptr, ptr %promise, i64 16
+  br label %_llgo_5
+
+clean:                                            ; preds = %_llgo_5
+  %1 = call ptr @llvm.coro.free(token %id, ptr %hdl)
+  br label %suspend
+
+suspend:                                          ; preds = %_llgo_5, %clean
+  %2 = call i1 @llvm.coro.end(ptr %hdl, i1 false, token none)
+  ret ptr %promise
+
+trap:                                             ; preds = %_llgo_5
+  call void @llvm.trap()
+  unreachable
+
+_llgo_5:                                          ; preds = %alloc, %entry
+  %frame = phi ptr [ null, %entry ], [ %0, %alloc ]
+  %hdl = call ptr @llvm.coro.begin(token %id, ptr %frame)
+  store ptr %hdl, ptr %promise, align 8
+  %3 = call ptr @async.GenInts()
+  %4 = call i8 @llvm.coro.suspend(token %id, i1 true)
+  switch i8 %4, label %suspend [
+    i8 0, label %trap
+    i8 1, label %clean
+  ]
+}
+
+define void @async.init() {
+_llgo_0:
+  %0 = load i1, ptr @"async.init$guard", align 1
+  br i1 %0, label %_llgo_2, label %_llgo_1
+
+_llgo_1:                                          ; preds = %_llgo_0
+  store i1 true, ptr @"async.init$guard", align 1
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  ret void
+}
+
+; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: read)
+declare token @llvm.coro.id(i32, ptr readnone, ptr nocapture readonly, ptr)
+
+; Function Attrs: nounwind memory(none)
+declare i64 @llvm.coro.size.i64()
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
+
+; Function Attrs: nounwind
+declare i1 @llvm.coro.alloc(token)
+
+; Function Attrs: nounwind
+declare ptr @llvm.coro.begin(token, ptr writeonly)
+
+; Function Attrs: nounwind memory(argmem: read)
+declare ptr @llvm.coro.free(token, ptr nocapture readonly)
+
+; Function Attrs: nounwind
+declare i1 @llvm.coro.end(ptr, i1, token)
+
+; Function Attrs: cold noreturn nounwind memory(inaccessiblemem: write)
+declare void @llvm.trap()
+
+define void @"github.com/goplus/llgo/x/async.(*Promise).setValue[int]"(ptr %0, i64 %1) {
+_llgo_0:
+  %2 = getelementptr inbounds %"github.com/goplus/llgo/x/async.Promise[int]", ptr %0, i32 0, i32 1
+  store i64 %1, ptr %2, align 4
+  ret void
+}
+
+; Function Attrs: nounwind
+declare i8 @llvm.coro.suspend(token, i1)
+
+define i1 @"github.com/goplus/llgo/x/async.(*Promise).Done[int]"(ptr %0) {
+_llgo_0:
+  %1 = getelementptr inbounds %"github.com/goplus/llgo/x/async.Promise[int]", ptr %0, i32 0, i32 0
+  %2 = load ptr, ptr %1, align 8
+  %3 = call i1 @llvm.coro.done(ptr %2)
+  %4 = zext i1 %3 to i64
+  %5 = trunc i64 %4 to i8
+  %6 = icmp ne i8 %5, 0
+  ret i1 %6
+}
+
+define i64 @"github.com/goplus/llgo/x/async.(*Promise).Value[int]"(ptr %0) {
+_llgo_0:
+  %1 = getelementptr inbounds %"github.com/goplus/llgo/x/async.Promise[int]", ptr %0, i32 0, i32 1
+  %2 = load i64, ptr %1, align 4
+  ret i64 %2
+}
+
+define void @"github.com/goplus/llgo/x/async.(*Promise).Next[int]"(ptr %0) {
+_llgo_0:
+  %1 = getelementptr inbounds %"github.com/goplus/llgo/x/async.Promise[int]", ptr %0, i32 0, i32 0
+  %2 = load ptr, ptr %1, align 8
+  call void @llvm.coro.resume(ptr %2)
+  ret void
+}
+
+; Function Attrs: nounwind memory(argmem: readwrite)
+declare i1 @llvm.coro.done(ptr nocapture readonly)
+
+declare void @llvm.coro.resume(ptr)
+

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/constant"
+	"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, nil)
+}
+
+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) getSetValueFunc(fn *ssa.Function) llssa.Function {
+	typ := fn.Signature.Recv().Type()
+	mthds := p.goProg.MethodSets.MethodSet(typ)
+	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[") {
+				setValueFn, _, _ := p.compileFunction(ssaMthd)
+				return setValueFn
+			}
+		}
+	}
+	panic("method setValue not found on type " + typ.String())
+}
+
+func (p *context) coReturn(b llssa.Builder, fn *ssa.Function, args []ssa.Value) {
+	setValueFn := p.getSetValueFunc(fn)
+	value := p.compileValue(b, args[1])
+	b.CoReturn(setValueFn, value)
+}
+
+func (p *context) coYield(b llssa.Builder, fn *ssa.Function, args []ssa.Value) {
+	setValueFn := p.getSetValueFunc(fn)
+	value := p.compileValue(b, args[1])
+	// TODO(lijie): find whether the co.Yield/co.Return is the last instruction
+	final := b.Const(constant.MakeBool(false), b.Prog.Bool())
+	b.CoYield(setValueFn, value, final)
+}
+
+func (p *context) coRun(b llssa.Builder, args []ssa.Value) {
+	panic("coRun(): not implemented")
+}

cl/compile.go

@@ -218,6 +218,7 @@ func (p *context) compileFuncDecl(pkg llssa.Package, f *ssa.Function) (llssa.Fun
 			log.Println("==> NewFunc", name, "type:", sig.Recv(), sig, "ftype:", ftype)
 		}
 	}
+	async := isAsyncFunc(f.Signature)
 	if fn == nil {
 		if name == "main" {
 			argc := types.NewParam(token.NoPos, pkgTypes, "", types.Typ[types.Int32])
@@ -227,13 +228,24 @@ func (p *context) compileFuncDecl(pkg llssa.Package, f *ssa.Function) (llssa.Fun
 			results := types.NewTuple(ret)
 			sig = types.NewSignatureType(nil, nil, nil, params, results, false)
 		}
-		fn = pkg.NewFuncEx(name, sig, llssa.Background(ftype), hasCtx)
+		fn = pkg.NewFuncEx(name, sig, llssa.Background(ftype), hasCtx, async)
 	}
-
+	nBlkOff := 0
 	if nblk := len(f.Blocks); nblk > 0 {
-		fn.MakeBlocks(nblk)   // to set fn.HasBody() = true
+		var entryBlk, allocBlk, cleanBlk, suspdBlk, trapBlk, beginBlk llssa.BasicBlock
+		if async {
+			nBlkOff = 5
+			entryBlk = fn.MakeBlock("entry")
+			allocBlk = fn.MakeBlock("alloc")
+			cleanBlk = fn.MakeBlock("clean")
+			suspdBlk = fn.MakeBlock("suspend")
+			trapBlk = fn.MakeBlock("trap")
+		}
+		fn.MakeBlocks(nblk) // to set fn.HasBody() = true
+		beginBlk = fn.Block(nBlkOff)
 		if f.Recover != nil { // set recover block
-			fn.SetRecover(fn.Block(f.Recover.Index))
+			// TODO(lijie): fix this for async function because of the block offset increase
+			fn.SetRecover(fn.Block(f.Recover.Index + nBlkOff))
 		}
 		p.inits = append(p.inits, func() {
 			p.fn = fn
@@ -249,6 +261,10 @@ func (p *context) compileFuncDecl(pkg llssa.Package, f *ssa.Function) (llssa.Fun
 				log.Println("==> FuncBody", name)
 			}
 			b := fn.NewBuilder()
+			b.SetBlockOffset(nBlkOff)
+			if async {
+				b.BeginAsync(fn, entryBlk, allocBlk, cleanBlk, suspdBlk, trapBlk, beginBlk)
+			}
 			p.bvals = make(map[ssa.Value]llssa.Expr)
 			off := make([]int, len(f.Blocks))
 			for i, block := range f.Blocks {
@@ -284,7 +300,7 @@ func (p *context) compileBlock(b llssa.Builder, block *ssa.BasicBlock, n int, do
 	var pkg = p.pkg
 	var fn = p.fn
 	var instrs = block.Instrs[n:]
-	var ret = fn.Block(block.Index)
+	var ret = fn.Block(block.Index + b.BlockOffset())
 	b.SetBlock(ret)
 	if doModInit {
 		if pyModInit = p.pyMod != ""; pyModInit {
@@ -322,7 +338,7 @@ func (p *context) compileBlock(b llssa.Builder, block *ssa.BasicBlock, n int, do
 		modPtr := pkg.PyNewModVar(modName, true).Expr
 		mod := b.Load(modPtr)
 		cond := b.BinOp(token.NEQ, mod, prog.Nil(mod.Type))
-		newBlk := fn.MakeBlock()
+		newBlk := fn.MakeBlock("")
 		b.If(cond, jumpTo, newBlk)
 		b.SetBlockEx(newBlk, llssa.AtEnd, false)
 		b.Store(modPtr, b.PyImportMod(modPath))
@@ -654,7 +670,11 @@ func (p *context) compileInstr(b llssa.Builder, instr ssa.Instruction) {
 			results = make([]llssa.Expr, 1)
 			results[0] = p.prog.IntVal(0, p.prog.CInt())
 		}
-		b.Return(results...)
+		if b.Async() {
+			b.EndAsync()
+		} else {
+			b.Return(results...)
+		}
 	case *ssa.If:
 		fn := p.fn
 		cond := p.compileValue(b, v.Cond)

cl/compile_test.go

@@ -53,7 +53,7 @@ func TestFromTestrt(t *testing.T) {
 }
 
 func TestFromTestdata(t *testing.T) {
-	cltest.FromDir(t, "", "./_testdata", false)
+	cltest.FromDir(t, "", "./_testdata", true)
 }
 
 func TestFromTestpymath(t *testing.T) {
@@ -124,3 +124,114 @@ _llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
 }
 `)
 }
+
+func TestAsyncFunc(t *testing.T) {
+	testCompile(t, `package foo
+
+import "github.com/goplus/llgo/x/async"
+
+func GenInts() (co *async.Promise[int]) {
+  co.Yield(1)
+  co.Yield(2)
+  return
+}
+`, `; ModuleID = 'foo'
+source_filename = "foo"
+
+@"foo.init$guard" = global i1 false, align 1
+
+define ptr @foo.GenInts() presplitcoroutine {
+entry:
+  %id = call token @llvm.coro.id(i32 0, ptr null, ptr null, ptr null)
+  %frame.size = call i64 @llvm.coro.size.i64()
+  %alloc.size = add i64 16, %frame.size
+  %promise = call ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64 %alloc.size)
+  %need.dyn.alloc = call i1 @llvm.coro.alloc(token %id)
+  br i1 %need.dyn.alloc, label %alloc, label %_llgo_5
+
+alloc:                                            ; preds = %entry
+  %0 = getelementptr ptr, ptr %promise, i64 16
+  br label %_llgo_5
+
+clean:                                            ; preds = %_llgo_7, %_llgo_6, %_llgo_5
+  %1 = call ptr @llvm.coro.free(token %id, ptr %hdl)
+  br label %suspend
+
+suspend:                                          ; preds = %_llgo_7, %_llgo_6, %_llgo_5, %clean
+  %2 = call i1 @llvm.coro.end(ptr %hdl, i1 false, token none)
+  ret ptr %promise
+
+trap:                                             ; preds = %_llgo_7
+  call void @llvm.trap()
+  unreachable
+
+_llgo_5:                                          ; preds = %alloc, %entry
+  %frame = phi ptr [ null, %entry ], [ %0, %alloc ]
+  %hdl = call ptr @llvm.coro.begin(token %id, ptr %frame)
+  store ptr %hdl, ptr %promise, align 8
+  call void @"github.com/goplus/llgo/x/async.(*Promise).setValue[int]"(ptr %promise, i64 1)
+  %3 = call i8 @llvm.coro.suspend(token %id, i1 false)
+  switch i8 %3, label %suspend [
+    i8 0, label %_llgo_6
+    i8 1, label %clean
+  ]
+
+_llgo_6:                                          ; preds = %_llgo_5
+  call void @"github.com/goplus/llgo/x/async.(*Promise).setValue[int]"(ptr %promise, i64 2)
+  %4 = call i8 @llvm.coro.suspend(token %id, i1 false)
+  switch i8 %4, label %suspend [
+    i8 0, label %_llgo_7
+    i8 1, label %clean
+  ]
+
+_llgo_7:                                          ; preds = %_llgo_6
+  %5 = call i8 @llvm.coro.suspend(token %id, i1 true)
+  switch i8 %5, label %suspend [
+    i8 0, label %trap
+    i8 1, label %clean
+  ]
+}
+
+define void @foo.init() {
+_llgo_0:
+  %0 = load i1, ptr @"foo.init$guard", align 1
+  br i1 %0, label %_llgo_2, label %_llgo_1
+
+_llgo_1:                                          ; preds = %_llgo_0
+  store i1 true, ptr @"foo.init$guard", align 1
+  br label %_llgo_2
+
+_llgo_2:                                          ; preds = %_llgo_1, %_llgo_0
+  ret void
+}
+
+; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: read)
+declare token @llvm.coro.id(i32, ptr readnone, ptr nocapture readonly, ptr)
+
+; Function Attrs: nounwind memory(none)
+declare i64 @llvm.coro.size.i64()
+
+declare ptr @"github.com/goplus/llgo/internal/runtime.AllocZ"(i64)
+
+; Function Attrs: nounwind
+declare i1 @llvm.coro.alloc(token)
+
+; Function Attrs: nounwind
+declare ptr @llvm.coro.begin(token, ptr writeonly)
+
+; Function Attrs: nounwind memory(argmem: read)
+declare ptr @llvm.coro.free(token, ptr nocapture readonly)
+
+; Function Attrs: nounwind
+declare i1 @llvm.coro.end(ptr, i1, token)
+
+; Function Attrs: cold noreturn nounwind memory(inaccessiblemem: write)
+declare void @llvm.trap()
+
+declare void @"github.com/goplus/llgo/x/async.(*Promise).setValue[int]"(ptr, i64)
+
+; Function Attrs: nounwind
+declare i8 @llvm.coro.suspend(token, i1)
+
+`)
+}

cl/import.go

@@ -412,7 +412,16 @@ const (
 	llgoAtomicUMax = llgoAtomicOpBase + llssa.OpUMax
 	llgoAtomicUMin = llgoAtomicOpBase + llssa.OpUMin
 
-	llgoAtomicOpLast = llgoAtomicOpBase + int(llssa.OpUMin)
+	llgoCoBase    = llgoInstrBase + 0x30
+	llgoCoAwait   = llgoCoBase + 0
+	llgoCoSuspend = llgoCoBase + 1
+	llgoCoDone    = llgoCoBase + 2
+	llgoCoResume  = llgoCoBase + 3
+	llgoCoReturn  = llgoCoBase + 4
+	llgoCoYield   = llgoCoBase + 5
+	llgoCoRun     = llgoCoBase + 6
+
+	llgoAtomicOpLast = llgoCoRun
 )
 
 func (p *context) funcName(fn *ssa.Function, ignore bool) (*types.Package, string, int) {

cl/instr.go

@@ -237,6 +237,14 @@ var llgoInstrs = map[string]int{
 	"atomicMin":  int(llgoAtomicMin),
 	"atomicUMax": int(llgoAtomicUMax),
 	"atomicUMin": int(llgoAtomicUMin),
+
+	"coAwait":   int(llgoCoAwait),
+	"coResume":  int(llgoCoResume),
+	"coSuspend": int(llgoCoSuspend),
+	"coDone":    int(llgoCoDone),
+	"coReturn":  int(llgoCoReturn),
+	"coYield":   int(llgoCoYield),
+	"coRun":     int(llgoCoRun),
 }
 
 // funcOf returns a function by name and set ftype = goFunc, cFunc, etc.
@@ -265,7 +273,8 @@ func (p *context) funcOf(fn *ssa.Function) (aFn llssa.Function, pyFn llssa.PyObj
 				return nil, nil, ignoredFunc
 			}
 			sig := fn.Signature
-			aFn = pkg.NewFuncEx(name, sig, llssa.Background(ftype), false)
+			async := isAsyncFunc(sig)
+			aFn = pkg.NewFuncEx(name, sig, llssa.Background(ftype), false, async)
 		}
 	}
 	return
@@ -390,6 +399,20 @@ func (p *context) call(b llssa.Builder, act llssa.DoAction, call *ssa.CallCommon
 			ret = p.funcAddr(b, args)
 		case llgoUnreachable: // func unreachable()
 			b.Unreachable()
+		case llgoCoAwait:
+			ret = p.coAwait(b, args)
+		case llgoCoSuspend:
+			p.coSuspend(b, p.prog.BoolVal(false))
+		case llgoCoDone:
+			return p.coDone(b, args)
+		case llgoCoResume:
+			p.coResume(b, args)
+		case llgoCoReturn:
+			p.coReturn(b, cv, args)
+		case llgoCoYield:
+			p.coYield(b, cv, args)
+		case llgoCoRun:
+			p.coRun(b, args)
 		default:
 			if ftype >= llgoAtomicOpBase && ftype <= llgoAtomicOpLast {
 				ret = p.atomic(b, llssa.AtomicOp(ftype-llgoAtomicOpBase), args)

ssa/cl_test.go

@@ -50,7 +50,7 @@ func TestFromTestrt(t *testing.T) {
 }
 
 func TestFromTestdata(t *testing.T) {
-	cltest.FromDir(t, "", "../cl/_testdata", false)
+	cltest.FromDir(t, "", "../cl/_testdata", true)
 }
 
 func TestMakeInterface(t *testing.T) {

ssa/coro.go

@@ -0,0 +1,690 @@
+/*
+ * 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 ssa
+
+import (
+	"fmt"
+	"go/constant"
+	"go/token"
+	"go/types"
+)
+
+// declare void @llvm.coro.destroy(ptr <handle>)
+// declare void @llvm.coro.resume(ptr <handle>)
+// declare i1 @llvm.coro.done(ptr <handle>)
+// declare ptr @llvm.coro.promise(ptr <ptr>, i32 <alignment>, i1 <from>)
+// declare i32 @llvm.coro.size.i32()
+// declare i64 @llvm.coro.size.i64()
+// declare i32 @llvm.coro.align.i32()
+// declare i64 @llvm.coro.align.i64()
+// declare ptr @llvm.coro.begin(token <id>, ptr <mem>)
+// declare ptr @llvm.coro.free(token %id, ptr <frame>)
+// declare i1 @llvm.coro.alloc(token <id>)
+// declare ptr @llvm.coro.noop()
+// declare ptr @llvm.coro.frame()
+// declare token @llvm.coro.id(i32 <align>, ptr <promise>, ptr <coroaddr>, ptr <fnaddrs>)
+// declare token @llvm.coro.id.async(i32 <context size>, i32 <align>, ptr <context arg>, ptr <async function pointer>)
+// declare token @llvm.coro.id.retcon(i32 <size>, i32 <align>, ptr <buffer>, ptr <continuation prototype>, ptr <alloc>, ptr <dealloc>)
+// declare token @llvm.coro.id.retcon.once(i32 <size>, i32 <align>, ptr <buffer>, ptr <prototype>, ptr <alloc>, ptr <dealloc>)
+// declare i1 @llvm.coro.end(ptr <handle>, i1 <unwind>, token <result.token>)
+// declare token @llvm.coro.end.results(...)
+// declare i1 @llvm.coro.end.async(ptr <handle>, i1 <unwind>, ...)
+// declare i8 @llvm.coro.suspend(token <save>, i1 <final>)
+// declare token @llvm.coro.save(ptr <handle>)
+// declare {ptr, ptr, ptr} @llvm.coro.suspend.async(ptr <resume function>, ptr <context projection function>, ... <function to call> ... <arguments to function>)
+// declare ptr @llvm.coro.prepare.async(ptr <coroutine function>)
+// declare i1 @llvm.coro.suspend.retcon(...)
+// declare void @await_suspend_function(ptr %awaiter, ptr %hdl)
+// declare void @llvm.coro.await.suspend.void(ptr <awaiter>, ptr <handle>, ptr <await_suspend_function>)
+// declare i1 @llvm.coro.await.suspend.bool(ptr <awaiter>, ptr <handle>, ptr <await_suspend_function>)
+// declare void @llvm.coro.await.suspend.handle(ptr <awaiter>, ptr <handle>, ptr <await_suspend_function>)
+
+// -----------------------------------------------------------------------------
+
+// declare void @llvm.coro.destroy(ptr <handle>)
+func (p Program) tyCoDestroy() *types.Signature {
+	if p.coDestroyTy == nil {
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i8Ptr)
+		p.coDestroyTy = types.NewSignatureType(nil, nil, nil, params, nil, false)
+	}
+	return p.coDestroyTy
+}
+
+// declare void @llvm.coro.resume(ptr <handle>)
+func (p Program) tyCoResume() *types.Signature {
+	if p.coResumeTy == nil {
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i8Ptr)
+		p.coResumeTy = types.NewSignatureType(nil, nil, nil, params, nil, false)
+	}
+	return p.coResumeTy
+}
+
+// declare i1 @llvm.coro.done(ptr <handle>)
+func (p Program) tyCoDone() *types.Signature {
+	if p.coDoneTy == nil {
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i8Ptr)
+		results := types.NewTuple(types.NewParam(token.NoPos, nil, "", p.Bool().raw.Type))
+		p.coDoneTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coDoneTy
+}
+
+// declare ptr @llvm.coro.promise(ptr <ptr>, i32 <alignment>, i1 <from>)
+func (p Program) tyCoPromise() *types.Signature {
+	if p.coPromiseTy == nil {
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		i32 := types.NewParam(token.NoPos, nil, "", p.Int32().raw.Type)
+		boolParam := types.NewParam(token.NoPos, nil, "", p.Bool().raw.Type)
+		params := types.NewTuple(i8Ptr, i32, boolParam)
+		results := types.NewTuple(i8Ptr)
+		p.coPromiseTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coPromiseTy
+}
+
+// declare i32 @llvm.coro.size.i32()
+func (p Program) tyCoSizeI32() *types.Signature {
+	if p.coSizeI32Ty == nil {
+		results := types.NewTuple(types.NewParam(token.NoPos, nil, "", p.Int32().raw.Type))
+		p.coSizeI32Ty = types.NewSignatureType(nil, nil, nil, nil, results, false)
+	}
+	return p.coSizeI32Ty
+}
+
+// declare i64 @llvm.coro.size.i64()
+func (p Program) tyCoSizeI64() *types.Signature {
+	if p.coSizeI64Ty == nil {
+		results := types.NewTuple(types.NewParam(token.NoPos, nil, "", p.Int64().raw.Type))
+		p.coSizeI64Ty = types.NewSignatureType(nil, nil, nil, nil, results, false)
+	}
+	return p.coSizeI64Ty
+}
+
+// declare i32 @llvm.coro.align.i32()
+func (p Program) tyCoAlignI32() *types.Signature {
+	if p.coAlignI32Ty == nil {
+		results := types.NewTuple(types.NewParam(token.NoPos, nil, "", p.Int32().raw.Type))
+		p.coAlignI32Ty = types.NewSignatureType(nil, nil, nil, nil, results, false)
+	}
+	return p.coAlignI32Ty
+}
+
+// declare i64 @llvm.coro.align.i64()
+func (p Program) tyCoAlignI64() *types.Signature {
+	if p.coAlignI64Ty == nil {
+		results := types.NewTuple(types.NewParam(token.NoPos, nil, "", p.Int64().raw.Type))
+		p.coAlignI64Ty = types.NewSignatureType(nil, nil, nil, nil, results, false)
+	}
+	return p.coAlignI64Ty
+}
+
+// declare ptr @llvm.coro.begin(token <id>, ptr <mem>)
+func (p Program) tyCoBegin() *types.Signature {
+	if p.coBeginTy == nil {
+		tokenParam := types.NewParam(token.NoPos, nil, "", p.Token().raw.Type)
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(tokenParam, i8Ptr)
+		results := types.NewTuple(i8Ptr)
+		p.coBeginTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coBeginTy
+}
+
+// declare ptr @llvm.coro.free(token %id, ptr <frame>)
+func (p Program) tyCoFree() *types.Signature {
+	if p.coFreeTy == nil {
+		tokenParam := types.NewParam(token.NoPos, nil, "", p.Token().raw.Type)
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(tokenParam, i8Ptr)
+		results := types.NewTuple(i8Ptr)
+		p.coFreeTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coFreeTy
+}
+
+// declare i1 @llvm.coro.alloc(token <id>)
+func (p Program) tyCoAlloc() *types.Signature {
+	if p.coAllocTy == nil {
+		tokenParam := types.NewParam(token.NoPos, nil, "", p.Token().raw.Type)
+		params := types.NewTuple(tokenParam)
+		boolParam := types.NewParam(token.NoPos, nil, "", p.Bool().raw.Type)
+		results := types.NewTuple(boolParam)
+		p.coAllocTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coAllocTy
+}
+
+// declare ptr @llvm.coro.noop()
+func (p Program) tyCoNoop() *types.Signature {
+	if p.coNoopTy == nil {
+		results := types.NewTuple(types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type))
+		p.coNoopTy = types.NewSignatureType(nil, nil, nil, nil, results, false)
+	}
+	return p.coNoopTy
+}
+
+// declare ptr @llvm.coro.frame()
+func (p Program) tyCoFrame() *types.Signature {
+	if p.coFrameTy == nil {
+		results := types.NewTuple(types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type))
+		p.coFrameTy = types.NewSignatureType(nil, nil, nil, nil, results, false)
+	}
+	return p.coFrameTy
+}
+
+// declare token @llvm.coro.id(i32 <align>, ptr <promise>, ptr <coroaddr>, ptr <fnaddrs>)
+func (p Program) tyCoID() *types.Signature {
+	if p.coIDTy == nil {
+		i32 := types.NewParam(token.NoPos, nil, "", p.Int32().raw.Type)
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i32, i8Ptr, i8Ptr, i8Ptr)
+		tokenParam := types.NewParam(token.NoPos, nil, "", p.Token().raw.Type)
+		results := types.NewTuple(tokenParam)
+		p.coIDTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coIDTy
+}
+
+/*
+// declare token @llvm.coro.id.async(i32 <context size>, i32 <align>, ptr <context arg>, ptr <async function pointer>)
+func (p Program) tyCoIDAsync() *types.Signature {
+	if p.coIDAsyncTy == nil {
+		i32 := types.NewParam(token.NoPos, nil, "", p.Int32().raw.Type)
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i32, i32, i8Ptr, i8Ptr)
+		tokenParam := types.NewParam(token.NoPos, nil, "", p.Token().raw.Type)
+		results := types.NewTuple(tokenParam)
+		p.coIDAsyncTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coIDAsyncTy
+}
+
+// declare token @llvm.coro.id.retcon(i32 <size>, i32 <align>, ptr <buffer>, ptr <continuation prototype>, ptr <alloc>, ptr <dealloc>)
+func (p Program) tyCoIDRetcon() *types.Signature {
+	if p.coIDRetconTy == nil {
+		i32 := types.NewParam(token.NoPos, nil, "", p.Int32().raw.Type)
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i32, i32, i8Ptr, i8Ptr, i8Ptr, i8Ptr)
+		tokenParam := types.NewParam(token.NoPos, nil, "", p.Token().raw.Type)
+		results := types.NewTuple(tokenParam)
+		p.coIDRetconTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coIDRetconTy
+}
+
+// declare token @llvm.coro.id.retcon.once(i32 <size>, i32 <align>, ptr <buffer>, ptr <prototype>, ptr <alloc>, ptr <dealloc>)
+func (p Program) tyCoIDRetconOnce() *types.Signature {
+	if p.coIDRetconOnceTy == nil {
+		i32 := types.NewParam(token.NoPos, nil, "", p.Int32().raw.Type)
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i32, i32, i8Ptr, i8Ptr, i8Ptr, i8Ptr)
+		tokenParam := types.NewParam(token.NoPos, nil, "", p.Token().raw.Type)
+		results := types.NewTuple(tokenParam)
+		p.coIDRetconOnceTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coIDRetconOnceTy
+}
+*/
+
+// declare i1 @llvm.coro.end(ptr <handle>, i1 <unwind>, token <result.token>)
+func (p Program) tyCoEnd() *types.Signature {
+	if p.coEndTy == nil {
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		boolParam := types.NewParam(token.NoPos, nil, "", p.Bool().raw.Type)
+		tokenParam := types.NewParam(token.NoPos, nil, "", p.Token().raw.Type)
+		params := types.NewTuple(i8Ptr, boolParam, tokenParam)
+		results := types.NewTuple(boolParam)
+		p.coEndTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coEndTy
+}
+
+/*
+// TODO(lijie): varargs
+// declare token @llvm.coro.end.results(...)
+func (p Program) tyCoEndResults() *types.Signature {
+	panic("not implemented")
+}
+
+// TODO(lijie): varargs
+// declare i1 @llvm.coro.end.async(ptr <handle>, i1 <unwind>, ...)
+func (p Program) tyCoEndAsync() *types.Signature {
+	panic("not implemented")
+}
+*/
+
+// declare i8 @llvm.coro.suspend(token <save>, i1 <final>)
+func (p Program) tyCoSuspend() *types.Signature {
+	if p.coSuspendTy == nil {
+		tokenParam := types.NewParam(token.NoPos, nil, "", p.Token().raw.Type)
+		boolParam := types.NewParam(token.NoPos, nil, "", p.Bool().raw.Type)
+		params := types.NewTuple(tokenParam, boolParam)
+		paramByte := types.NewParam(token.NoPos, nil, "", p.Byte().raw.Type)
+		results := types.NewTuple(paramByte)
+		p.coSuspendTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coSuspendTy
+}
+
+/*
+// declare token @llvm.coro.save(ptr <handle>)
+func (p Program) tyCoSave() *types.Signature {
+	if p.coSaveTy == nil {
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i8Ptr)
+		tokenParam := types.NewParam(token.NoPos, nil, "", p.Token().raw.Type)
+		results := types.NewTuple(tokenParam)
+		p.coSaveTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coSaveTy
+}
+
+// TODO(lijie): varargs
+// declare {ptr, ptr, ptr} @llvm.coro.suspend.async(ptr <resume function>, ptr <context projection function>, ... <function to call> ... <arguments to function>)
+func (p Program) tyCoSuspendAsync() *types.Signature {
+	panic("not implemented")
+}
+
+// declare ptr @llvm.coro.prepare.async(ptr <coroutine function>)
+func (p Program) tyCoPrepareAsync() *types.Signature {
+	if p.coPrepareAsyncTy == nil {
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i8Ptr)
+		results := types.NewTuple(i8Ptr)
+		p.coPrepareAsyncTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coPrepareAsyncTy
+}
+
+// declare i1 @llvm.coro.suspend.retcon(...)
+func (p Program) tyCoSuspendRetcon() *types.Signature {
+	panic("not implemented")
+}
+
+// declare void @await_suspend_function(ptr %awaiter, ptr %hdl)
+func (p Program) tyCoAwaitSuspendFunction() *types.Signature {
+	if p.coAwaitSuspendFunctionTy == nil {
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i8Ptr, i8Ptr)
+		p.coAwaitSuspendFunctionTy = types.NewSignatureType(nil, nil, nil, params, nil, false)
+	}
+	return p.coAwaitSuspendFunctionTy
+}
+
+// declare void @llvm.coro.await.suspend.void(ptr <awaiter>, ptr <handle>, ptr <await_suspend_function>)
+func (p Program) tyCoAwaitSuspendVoid() *types.Signature {
+	if p.coAwaitSuspendVoidTy == nil {
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i8Ptr, i8Ptr, i8Ptr)
+		p.coAwaitSuspendVoidTy = types.NewSignatureType(nil, nil, nil, params, nil, false)
+	}
+	return p.coAwaitSuspendVoidTy
+}
+
+// declare i1 @llvm.coro.await.suspend.bool(ptr <awaiter>, ptr <handle>, ptr <await_suspend_function>)
+func (p Program) tyCoAwaitSuspendBool() *types.Signature {
+	if p.coAwaitSuspendBoolTy == nil {
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i8Ptr, i8Ptr, i8Ptr)
+		results := types.NewTuple(types.NewParam(token.NoPos, nil, "", p.Bool().raw.Type))
+		p.coAwaitSuspendBoolTy = types.NewSignatureType(nil, nil, nil, params, results, false)
+	}
+	return p.coAwaitSuspendBoolTy
+}
+
+// declare void @llvm.coro.await.suspend.handle(ptr <awaiter>, ptr <handle>, ptr <await_suspend_function>)
+func (p Program) tyCoAwaitSuspendHandle() *types.Signature {
+	if p.coAwaitSuspendHandleTy == nil {
+		i8Ptr := types.NewParam(token.NoPos, nil, "", p.VoidPtr().raw.Type)
+		params := types.NewTuple(i8Ptr, i8Ptr, i8Ptr)
+		p.coAwaitSuspendHandleTy = types.NewSignatureType(nil, nil, nil, params, nil, false)
+	}
+	return p.coAwaitSuspendHandleTy
+}
+*/
+
+// -----------------------------------------------------------------------------
+
+func (b Builder) SetBlockOffset(offset int) {
+	b.blkOffset = offset
+}
+
+func (b Builder) BlockOffset() int {
+	return b.blkOffset
+}
+
+func (b Builder) Async() bool {
+	return b.async
+}
+
+func (b Builder) AsyncToken() Expr {
+	return b.asyncToken
+}
+
+func (b Builder) EndAsync() {
+	b.onReturn()
+}
+
+/*
+	pesudo code:
+
+retPtr := malloc(sizeof(Promise))
+id := @llvm.coro.id(0, null, null, null)
+promiseSize := sizeof(Promise[T])
+frameSize := @llvm.coro.size.i64()
+allocSize := promiseSize + frameSize
+promise := malloc(allocSize)
+needAlloc := @llvm.coro.alloc(id)
+; Allocate memory for return type and coroutine frame
+frame := null
+
+	if needAlloc {
+		frame := malloc(frameSize)
+	}
+
+hdl := @llvm.coro.begin(id, frame)
+*retPtr = hdl
+*/
+func (b Builder) BeginAsync(fn Function, entryBlk, allocBlk, cleanBlk, suspdBlk, trapBlk, beginBlk BasicBlock) {
+	ty := fn.Type.RawType().(*types.Signature).Results().At(0).Type()
+	ptrTy, ok := ty.(*types.Pointer)
+	if !ok {
+		panic("async function must return a *async.Promise")
+	}
+	promiseTy := b.Prog.Type(ptrTy.Elem(), InGo)
+
+	b.async = true
+
+	b.SetBlock(entryBlk)
+	align := b.Const(constant.MakeInt64(0), b.Prog.CInt()).SetName("align")
+	null := b.Const(nil, b.Prog.CIntPtr())
+	id := b.CoID(align, null, null, null).SetName("id")
+	b.asyncToken = id
+	promiseSize := b.Const(constant.MakeUint64(b.Prog.SizeOf(promiseTy)), b.Prog.Int64()).SetName("alloc.size")
+	frameSize := b.CoSizeI64().SetName("frame.size")
+	allocSize := b.BinOp(token.ADD, promiseSize, frameSize).SetName("alloc.size")
+	promise := b.AllocZ(allocSize).SetName("promise")
+	b.promise = promise
+	promise.Type = b.Prog.Pointer(promiseTy)
+	needAlloc := b.CoAlloc(id).SetName("need.dyn.alloc")
+	b.If(needAlloc, allocBlk, beginBlk)
+
+	b.SetBlock(allocBlk)
+	frame := b.OffsetPtr(promise, promiseSize)
+	b.Jump(beginBlk)
+
+	b.SetBlock(beginBlk)
+	phi := b.Phi(b.Prog.VoidPtr())
+	phi.SetName("frame")
+	phi.AddIncoming(b, []BasicBlock{entryBlk, allocBlk}, func(i int, blk BasicBlock) Expr {
+		if i == 0 {
+			return null
+		}
+		return frame
+	})
+	hdl := b.CoBegin(id, phi.Expr)
+	hdl.SetName("hdl")
+	b.Store(promise, hdl)
+
+	b.SetBlock(cleanBlk)
+	b.CoFree(id, hdl)
+	b.Jump(suspdBlk)
+
+	b.SetBlock(suspdBlk)
+	b.CoEnd(hdl, b.Prog.BoolVal(false), b.Prog.TokenNone())
+	b.Return(promise)
+
+	b.SetBlock(trapBlk)
+	b.LLVMTrap()
+	b.Unreachable()
+
+	b.onSuspBlk = func(nextBlk BasicBlock) (BasicBlock, BasicBlock, BasicBlock) {
+		if nextBlk == nil {
+			nextBlk = trapBlk
+		}
+		return suspdBlk, nextBlk, cleanBlk
+	}
+	b.onReturn = func() {
+		b.CoSuspend(b.asyncToken, b.Prog.BoolVal(true), trapBlk)
+	}
+}
+
+// -----------------------------------------------------------------------------
+
+// declare void @llvm.coro.destroy(ptr <handle>)
+func (b Builder) CoDestroy(hdl Expr) {
+	fn := b.Pkg.cFunc("llvm.coro.destroy", b.Prog.tyCoDestroy())
+	b.Call(fn, hdl)
+}
+
+// declare void @llvm.coro.resume(ptr <handle>)
+func (b Builder) CoResume(hdl Expr) {
+	fn := b.Pkg.cFunc("llvm.coro.resume", b.Prog.tyCoResume())
+	b.Call(fn, hdl)
+}
+
+// declare i1 @llvm.coro.done(ptr <handle>)
+func (b Builder) coDone(hdl Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.done", b.Prog.tyCoDone())
+	return b.Call(fn, hdl)
+}
+
+// return c.Char
+func (b Builder) CoDone(hdl Expr) Expr {
+	bvar := b.coDone(hdl)
+	// TODO(lijie): inefficient
+	// %6 = zext i1 %5 to i64
+	// %7 = trunc i64 %6 to i8
+	return b.valFromData(b.Prog.Byte(), bvar.impl)
+}
+
+// declare ptr @llvm.coro.promise(ptr <ptr>, i32 <alignment>, i1 <from>)
+func (b Builder) CoPromise(ptr, align, from Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.promise", b.Prog.tyCoPromise())
+	return b.Call(fn, ptr, align, from)
+}
+
+// declare i32 @llvm.coro.size.i32()
+func (b Builder) CoSizeI32() Expr {
+	fn := b.Pkg.cFunc("llvm.coro.size.i32", b.Prog.tyCoSizeI32())
+	return b.Call(fn)
+}
+
+// declare i64 @llvm.coro.size.i64()
+func (b Builder) CoSizeI64() Expr {
+	fn := b.Pkg.cFunc("llvm.coro.size.i64", b.Prog.tyCoSizeI64())
+	return b.Call(fn)
+}
+
+// declare i32 @llvm.coro.align.i32()
+func (b Builder) CoAlignI32() Expr {
+	fn := b.Pkg.cFunc("llvm.coro.align.i32", b.Prog.tyCoAlignI32())
+	return b.Call(fn)
+}
+
+// declare i64 @llvm.coro.align.i64()
+func (b Builder) CoAlignI64() Expr {
+	fn := b.Pkg.cFunc("llvm.coro.align.i64", b.Prog.tyCoAlignI64())
+	return b.Call(fn)
+}
+
+// declare ptr @llvm.coro.begin(token <id>, ptr <mem>)
+func (b Builder) CoBegin(id, mem Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.begin", b.Prog.tyCoBegin())
+	return b.Call(fn, id, mem)
+}
+
+// declare ptr @llvm.coro.free(token %id, ptr <frame>)
+func (b Builder) CoFree(id, frame Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.free", b.Prog.tyCoFree())
+	return b.Call(fn, id, frame)
+}
+
+// declare i1 @llvm.coro.alloc(token <id>)
+func (b Builder) CoAlloc(id Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.alloc", b.Prog.tyCoAlloc())
+	return b.Call(fn, id)
+}
+
+// declare ptr @llvm.coro.noop()
+func (b Builder) CoNoop() Expr {
+	fn := b.Pkg.cFunc("llvm.coro.noop", b.Prog.tyCoNoop())
+	return b.Call(fn)
+}
+
+// declare ptr @llvm.coro.frame()
+func (b Builder) CoFrame() Expr {
+	fn := b.Pkg.cFunc("llvm.coro.frame", b.Prog.tyCoFrame())
+	return b.Call(fn)
+}
+
+// declare token @llvm.coro.id(i32 <align>, ptr <promise>, ptr <coroaddr>, ptr <fnaddrs>)
+func (b Builder) CoID(align Expr, promise, coroAddr, fnAddrs Expr) Expr {
+	if align.Type != b.Prog.Int32() {
+		panic("align must be i32")
+	}
+	fn := b.Pkg.cFunc("llvm.coro.id", b.Prog.tyCoID())
+	return b.Call(fn, align, promise, coroAddr, fnAddrs)
+}
+
+/*
+// declare token @llvm.coro.id.async(i32 <context size>, i32 <align>, ptr <context arg>, ptr <async function pointer>)
+func (b Builder) CoIDAsync(contextSize, align, contextArg, asyncFnPtr Expr) Expr {
+	if contextSize.Type != b.Prog.Int32() {
+		panic("contextSize must be i32")
+	}
+	if align.Type != b.Prog.Int32() {
+		panic("align must be i32")
+	}
+	fn := b.Pkg.cFunc("llvm.coro.id.async", b.Prog.tyCoIDAsync())
+	return b.Call(fn, contextSize, align, contextArg, asyncFnPtr)
+}
+
+// declare token @llvm.coro.id.retcon(i32 <size>, i32 <align>, ptr <buffer>, ptr <continuation prototype>, ptr <alloc>, ptr <dealloc>)
+func (b Builder) CoIDRetcon(size, align, buffer, contProto, alloc, dealloc Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.id.retcon", b.Prog.tyCoIDRetcon())
+	return b.Call(fn, size, align, buffer, contProto, alloc, dealloc)
+}
+
+// declare token @llvm.coro.id.retcon.once(i32 <size>, i32 <align>, ptr <buffer>, ptr <prototype>, ptr <alloc>, ptr <dealloc>)
+func (b Builder) CoIDRetconOnce(size, align, buffer, prototype, alloc, dealloc Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.id.retcon.once", b.Prog.tyCoIDRetconOnce())
+	return b.Call(fn, size, align, buffer, prototype, alloc, dealloc)
+}
+*/
+
+// declare i1 @llvm.coro.end(ptr <handle>, i1 <unwind>, token <result.token>)
+func (b Builder) CoEnd(hdl Expr, unwind Expr, resultToken Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.end", b.Prog.tyCoEnd())
+	return b.Call(fn, hdl, unwind, resultToken)
+}
+
+/*
+// declare token @llvm.coro.end.results(...)
+func (b Builder) CoEndResults(args []Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.end.results", b.Prog.tyCoEndResults())
+	return b.Call(fn, args...)
+}
+
+// declare i1 @llvm.coro.end.async(ptr <handle>, i1 <unwind>, ...)
+func (b Builder) CoEndAsync(handle, unwind Expr, args ...Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.end.async", b.Prog.tyCoEndAsync())
+	vargs := append([]Expr{handle, unwind}, args...)
+	return b.Call(fn, vargs...)
+}
+*/
+
+// declare i8 @llvm.coro.suspend(token <save>, i1 <final>)
+func (b Builder) coSuspend(save, final Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.suspend", b.Prog.tyCoSuspend())
+	return b.Call(fn, save, final)
+}
+
+func (b Builder) CoSuspend(save, final Expr, nextBlk BasicBlock) {
+	if !b.async {
+		panic(fmt.Errorf("suspend %v not in async block", b.Func.Name()))
+	}
+	if nextBlk == nil {
+		b.Func.MakeBlock("")
+		nextBlk = b.Func.Block(b.blk.idx + 1)
+	}
+	ret := b.coSuspend(save, final)
+	susp, next, clean := b.onSuspBlk(nextBlk)
+	swt := b.Switch(ret, susp)
+	swt.Case(b.Const(constant.MakeInt64(0), b.Prog.Byte()), next)
+	swt.Case(b.Const(constant.MakeInt64(1), b.Prog.Byte()), clean)
+	swt.End(b)
+	b.SetBlock(nextBlk)
+}
+
+func (b Builder) CoReturn(setValueFn Function, value Expr) {
+	if !b.async {
+		panic(fmt.Errorf("return %v not in async block", b.Func.Name()))
+	}
+	b.Call(setValueFn.Expr, b.promise, value)
+	_, _, cleanBlk := b.onSuspBlk(nil)
+	b.Jump(cleanBlk)
+}
+
+func (b Builder) CoYield(setValueFn Function, value Expr, final Expr) {
+	if !b.async {
+		panic(fmt.Errorf("yield %v not in async block", b.Func.Name()))
+	}
+	b.Call(setValueFn.Expr, b.promise, value)
+	b.CoSuspend(b.AsyncToken(), final, nil)
+}
+
+/*
+// declare token @llvm.coro.save(ptr <handle>)
+func (b Builder) CoSave(hdl Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.save", b.Prog.tyCoSave())
+	return b.Call(fn, hdl)
+}
+
+// declare ptr @llvm.coro.prepare.async(ptr <coroutine function>)
+func (b Builder) CoPrepareAsync(f Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.prepare.async", b.Prog.tyCoPrepareAsync())
+	return b.Call(fn, f)
+}
+
+// declare i1 @llvm.coro.suspend.retcon(...)
+func (b Builder) CoSuspendRetcon(args []Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.suspend.retcon", b.Prog.tyCoSuspendRetcon())
+	return b.Call(fn, args...)
+}
+
+// declare void @llvm.coro.await.suspend.void(ptr <awaiter>, ptr <handle>, ptr <await_suspend_function>)
+func (b Builder) CoAwaitSuspendVoid(awaiter, handle, f Expr) {
+	fn := b.Pkg.cFunc("llvm.coro.await.suspend.void", b.Prog.tyCoAwaitSuspendVoid())
+	b.Call(fn, awaiter, handle, f)
+}
+
+// declare i1 @llvm.coro.await.suspend.bool(ptr <awaiter>, ptr <handle>, ptr <await_suspend_function>)
+func (b Builder) CoAwaitSuspendBool(awaiter, handle, f Expr) Expr {
+	fn := b.Pkg.cFunc("llvm.coro.await.suspend.bool", b.Prog.tyCoAwaitSuspendBool())
+	return b.Call(fn, awaiter, handle, f)
+}
+
+// declare void @llvm.coro.await.suspend.handle(ptr <awaiter>, ptr <handle>, ptr <await_suspend_function>)
+func (b Builder) CoAwaitSuspendHandle(awaiter, handle, f Expr) {
+	fn := b.Pkg.cFunc("llvm.coro.await.suspend.handle", b.Prog.tyCoAwaitSuspendHandle())
+	b.Call(fn, awaiter, handle, f)
+}
+*/

ssa/decl.go

@@ -180,11 +180,11 @@ type Function = *aFunction
 
 // NewFunc creates a new function.
 func (p Package) NewFunc(name string, sig *types.Signature, bg Background) Function {
-	return p.NewFuncEx(name, sig, bg, false)
+	return p.NewFuncEx(name, sig, bg, false, false)
 }
 
 // NewFuncEx creates a new function.
-func (p Package) NewFuncEx(name string, sig *types.Signature, bg Background, hasFreeVars bool) Function {
+func (p Package) NewFuncEx(name string, sig *types.Signature, bg Background, hasFreeVars, async bool) Function {
 	if v, ok := p.fns[name]; ok {
 		return v
 	}
@@ -193,6 +193,9 @@ func (p Package) NewFuncEx(name string, sig *types.Signature, bg Background, has
 		log.Println("NewFunc", name, t.raw.Type, "hasFreeVars:", hasFreeVars)
 	}
 	fn := llvm.AddFunction(p.mod, name, t.ll)
+	if async {
+		fn.AddFunctionAttr(p.Prog.ctx.CreateStringAttribute("presplitcoroutine", ""))
+	}
 	ret := newFunction(fn, t, p, p.Prog, hasFreeVars)
 	p.fns[name] = ret
 	return ret
@@ -268,7 +271,7 @@ func (p Function) NewBuilder() Builder {
 	b := prog.ctx.NewBuilder()
 	// TODO(xsw): Finalize may cause panic, so comment it.
 	// b.Finalize()
-	return &aBuilder{b, nil, p, p.Pkg, prog}
+	return &aBuilder{impl: b, blk: nil, Func: p, Pkg: p.Pkg, Prog: prog}
 }
 
 // HasBody reports whether the function has a body.
@@ -293,13 +296,15 @@ func (p Function) MakeBlocks(nblk int) []BasicBlock {
 		p.blks = make([]BasicBlock, 0, nblk)
 	}
 	for i := 0; i < nblk; i++ {
-		p.addBlock(n + i)
+		p.addBlock(n+i, "")
 	}
 	return p.blks[n:]
 }
 
-func (p Function) addBlock(idx int) BasicBlock {
+func (p Function) addBlock(idx int, label string) BasicBlock {
-	label := "_llgo_" + strconv.Itoa(idx)
+	if label == "" {
+		label = "_llgo_" + strconv.Itoa(idx)
+	}
 	blk := llvm.AddBasicBlock(p.impl, label)
 	ret := &aBasicBlock{blk, blk, p, idx}
 	p.blks = append(p.blks, ret)
@@ -307,8 +312,8 @@ func (p Function) addBlock(idx int) BasicBlock {
 }
 
 // MakeBlock creates a new basic block for the function.
-func (p Function) MakeBlock() BasicBlock {
+func (p Function) MakeBlock(label string) BasicBlock {
-	return p.addBlock(len(p.blks))
+	return p.addBlock(len(p.blks), label)
 }
 
 // Block returns the ith basic block of the function.

ssa/eh.go

@@ -55,6 +55,13 @@ func (p Program) tySiglongjmp() *types.Signature {
 	return p.sigljmpTy
 }
 
+func (p Program) tyLLVMTrap() *types.Signature {
+	if p.llvmTrapTy == nil {
+		p.llvmTrapTy = types.NewSignatureType(nil, nil, nil, nil, nil, false)
+	}
+	return p.llvmTrapTy
+}
+
 func (b Builder) AllocaSigjmpBuf() Expr {
 	prog := b.Prog
 	n := unsafe.Sizeof(sigjmpbuf{})
@@ -77,6 +84,11 @@ func (b Builder) Siglongjmp(jb, retval Expr) {
 	// b.Unreachable()
 }
 
+func (b Builder) LLVMTrap() {
+	fn := b.Pkg.cFunc("llvm.trap", b.Prog.tyLLVMTrap())
+	b.Call(fn)
+}
+
 // -----------------------------------------------------------------------------
 
 const (
@@ -166,7 +178,7 @@ func (b Builder) getDefer(kind DoAction) *aDefer {
 		czero := prog.IntVal(0, prog.CInt())
 		retval := b.Sigsetjmp(jb, czero)
 		if kind != DeferAlways {
-			panicBlk = self.MakeBlock()
+			panicBlk = self.MakeBlock("")
 		} else {
 			blks = self.MakeBlocks(2)
 			next, panicBlk = blks[0], blks[1]
@@ -240,7 +252,7 @@ func (b Builder) Defer(kind DoAction, fn Expr, args ...Expr) {
 // RunDefers emits instructions to run deferred instructions.
 func (b Builder) RunDefers() {
 	self := b.getDefer(DeferInCond)
-	blk := b.Func.MakeBlock()
+	blk := b.Func.MakeBlock("")
 	self.rundsNext = append(self.rundsNext, blk)
 
 	b.Store(self.rundPtr, blk.Addr())

ssa/expr.go

@@ -59,6 +59,11 @@ func (v Expr) SetOrdering(ordering AtomicOrdering) Expr {
 	return v
 }
 
+func (v Expr) SetName(name string) Expr {
+	v.impl.SetName(name)
+	return v
+}
+
 // -----------------------------------------------------------------------------
 
 type builtinTy struct {

ssa/memory.go

@@ -232,6 +232,13 @@ func (b Builder) ArrayAlloca(telem Type, n Expr) (ret Expr) {
 	return
 }
 
+func (b Builder) OffsetPtr(ptr, offset Expr) Expr {
+	if debugInstr {
+		log.Printf("OffsetPtr %v, %v\n", ptr.impl, offset.impl)
+	}
+	return Expr{llvm.CreateGEP(b.impl, ptr.Type.ll, ptr.impl, []llvm.Value{offset.impl}), ptr.Type}
+}
+
 /* TODO(xsw):
 // ArrayAlloc allocates zero initialized space for an array of n elements of type telem.
 func (b Builder) ArrayAlloc(telem Type, n Expr) (ret Expr) {

ssa/package.go

@@ -19,8 +19,10 @@ package ssa
 import (
 	"go/token"
 	"go/types"
+	"regexp"
 	"runtime"
 	"strconv"
+	"strings"
 	"unsafe"
 
 	"github.com/goplus/llgo/ssa/abi"
@@ -136,6 +138,8 @@ type aProgram struct {
 	rtMapTy    llvm.Type
 	rtChanTy   llvm.Type
 
+	tokenType llvm.Type
+
 	anyTy     Type
 	voidTy    Type
 	voidPtr   Type
@@ -166,6 +170,8 @@ type aProgram struct {
 	deferTy   Type
 	deferPtr  Type
 
+	tokenTy Type
+
 	pyImpTy      *types.Signature
 	pyNewList    *types.Signature
 	pyListSetI   *types.Signature
@@ -189,6 +195,41 @@ type aProgram struct {
 	sigsetjmpTy *types.Signature
 	sigljmpTy   *types.Signature
 
+	llvmTrapTy *types.Signature
+
+	// coroutine manipulation intrinsics (ordered by LLVM coroutine doc)
+	coDestroyTy *types.Signature
+	coResumeTy  *types.Signature
+	coDoneTy    *types.Signature
+	coPromiseTy *types.Signature
+
+	// coroutine structure intrinsics (ordered by LLVM coroutine doc)
+	coSizeI32Ty  *types.Signature
+	coSizeI64Ty  *types.Signature
+	coAlignI32Ty *types.Signature
+	coAlignI64Ty *types.Signature
+	coBeginTy    *types.Signature
+	coFreeTy     *types.Signature
+	coAllocTy    *types.Signature
+	coNoopTy     *types.Signature
+	coFrameTy    *types.Signature
+	coIDTy       *types.Signature
+	// coIDAsyncTy              *types.Signature
+	// coIDRetconTy             *types.Signature
+	// coIDRetconOnceTy         *types.Signature
+	coEndTy *types.Signature
+	// coEndResultsTy           *types.Signature
+	// coEndAsyncTy             *types.Signature
+	coSuspendTy *types.Signature
+	// coSaveTy                 *types.Signature
+	// coSuspendAsyncTy         *types.Signature
+	// coPrepareAsyncTy         *types.Signature
+	// coSuspendRetconTy        *types.Signature
+	// coAwaitSuspendFunctionTy *types.Signature
+	// coAwaitSuspendVoidTy     *types.Signature
+	// coAwaitSuspendBoolTy     *types.Signature
+	// coAwaitSuspendHandleTy   *types.Signature
+
 	paramObjPtr_ *types.Var
 
 	ptrSize int
@@ -441,6 +482,18 @@ func (p Program) Any() Type {
 	return p.anyTy
 }
 
+func (p Program) Token() Type {
+	if p.tokenTy == nil {
+		p.tokenTy = &aType{p.tyToken(), rawType{types.Typ[types.Invalid]}, vkInvalid}
+	}
+	return p.tokenTy
+}
+
+func (p Program) TokenNone() Expr {
+	impl := llvm.ConstNull(p.Token().ll)
+	return Expr{impl: impl, Type: p.Token()}
+}
+
 /*
 // Eface returns the empty interface type.
 // It is equivalent to Any.
@@ -649,9 +702,41 @@ func (p Package) Path() string {
 	return p.abi.Pkg
 }
 
+// Find presplitcoroutine attribute and replace attribute tag with it
+// e.g. attributes #0 = { noinline nounwind readnone "presplitcoroutine" }
+// replace #0 with presplitcoroutine
+// and also remove all other attributes
+func removeLLVMAttributes(ll string) string {
+	attrRe := regexp.MustCompile(`^attributes (#\d+) = {[^}]*}$`)
+	attrRe2 := regexp.MustCompile(`(\) #\d+ {|\) #\d+)$`)
+	lines := strings.Split(ll, "\n")
+	newLines := make([]string, 0, len(lines))
+	presplitcoroutine := ""
+	for _, line := range lines {
+		if m := attrRe.FindStringSubmatch(line); m != nil {
+			if strings.Contains(line, "\"presplitcoroutine\"") {
+				presplitcoroutine = " " + m[1] + " "
+			}
+		} else {
+			newLines = append(newLines, line)
+		}
+	}
+
+	for i, line := range newLines {
+		if presplitcoroutine != "" {
+			line = strings.Replace(line, presplitcoroutine, " presplitcoroutine ", 1)
+		}
+		line = attrRe2.ReplaceAllString(line, ")")
+		newLines[i] = line
+	}
+
+	return strings.Join(newLines, "\n")
+}
+
 // String returns a string representation of the package.
 func (p Package) String() string {
-	return p.mod.String()
+	// TODO(lijie): workaround for compiling errors of LLVM attributes
+	return removeLLVMAttributes(p.mod.String())
 }
 
 // SetPatch sets a patch function.

ssa/ssa_test.go

@@ -469,6 +469,47 @@ _llgo_0:
 `)
 }
 
+func TestSwitch(t *testing.T) {
+	prog := NewProgram(nil)
+	pkg := prog.NewPackage("bar", "foo/bar")
+	params := types.NewTuple(types.NewVar(0, nil, "a", types.Typ[types.Int]))
+	rets := types.NewTuple(types.NewVar(0, nil, "", types.Typ[types.Int]))
+	sig := types.NewSignatureType(nil, nil, nil, params, rets, false)
+	fn := pkg.NewFunc("fn", sig, InGo)
+	b := fn.MakeBody(4)
+	cond := fn.Param(0)
+	case1 := fn.Block(1)
+	case2 := fn.Block(2)
+	defb := fn.Block(3)
+	swc := b.Switch(cond, defb)
+	swc.Case(prog.Val(1), case1)
+	swc.Case(prog.Val(2), case2)
+	swc.End(b)
+	b.SetBlock(case1).Return(prog.Val(3))
+	b.SetBlock(case2).Return(prog.Val(4))
+	b.SetBlock(defb).Return(prog.Val(5))
+	assertPkg(t, pkg, `; ModuleID = 'foo/bar'
+source_filename = "foo/bar"
+
+define i64 @fn(i64 %0) {
+_llgo_0:
+  switch i64 %0, label %_llgo_3 [
+    i64 1, label %_llgo_1
+    i64 2, label %_llgo_2
+  ]
+
+_llgo_1:                                          ; preds = %_llgo_0
+  ret i64 3
+
+_llgo_2:                                          ; preds = %_llgo_0
+  ret i64 4
+
+_llgo_3:                                          ; preds = %_llgo_0
+  ret i64 5
+}
+`)
+}
+
 func TestUnOp(t *testing.T) {
 	prog := NewProgram(nil)
 	pkg := prog.NewPackage("bar", "foo/bar")
@@ -552,3 +593,194 @@ _llgo_0:
 }
 `)
 }
+
+func TestPointerOffset(t *testing.T) {
+	prog := NewProgram(nil)
+	pkg := prog.NewPackage("bar", "foo/bar")
+	params := types.NewTuple(
+		types.NewVar(0, nil, "p", types.NewPointer(types.Typ[types.Int])),
+		types.NewVar(0, nil, "offset", types.Typ[types.Int]),
+	)
+	rets := types.NewTuple(types.NewVar(0, nil, "", types.NewPointer(types.Typ[types.Int])))
+	sig := types.NewSignatureType(nil, nil, nil, params, rets, false)
+	fn := pkg.NewFunc("fn", sig, InGo)
+	b := fn.MakeBody(1)
+	ptr := fn.Param(0)
+	offset := fn.Param(1)
+	result := b.OffsetPtr(ptr, offset)
+	b.Return(result)
+	assertPkg(t, pkg, `; ModuleID = 'foo/bar'
+source_filename = "foo/bar"
+
+define ptr @fn(ptr %0, i64 %1) {
+_llgo_0:
+  %2 = getelementptr ptr, ptr %0, i64 %1
+  ret ptr %2
+}
+`)
+}
+
+func TestLLVMTrap(t *testing.T) {
+	prog := NewProgram(nil)
+	pkg := prog.NewPackage("bar", "foo/bar")
+	b := pkg.NewFunc("fn", NoArgsNoRet, InGo).MakeBody(1)
+	b.LLVMTrap()
+	b.Unreachable()
+	assertPkg(t, pkg, `; ModuleID = 'foo/bar'
+source_filename = "foo/bar"
+
+define void @fn() {
+_llgo_0:
+  call void @llvm.trap()
+  unreachable
+}
+
+; Function Attrs: cold noreturn nounwind memory(inaccessiblemem: write)
+declare void @llvm.trap()
+
+`)
+}
+
+func TestCoroFuncs(t *testing.T) {
+	prog := NewProgram(nil)
+	pkg := prog.NewPackage("bar", "foo/bar")
+	fn := pkg.NewFunc("fn", NoArgsNoRet, InGo)
+	entryBlk := fn.MakeBlock("entry")
+	suspdBlk := fn.MakeBlock("suspend")
+	cleanBlk := fn.MakeBlock("clean")
+	b := fn.NewBuilder()
+	b.async = true
+
+	b.SetBlock(entryBlk)
+	align := b.Const(constant.MakeInt64(0), prog.Int32())
+	align8 := b.Const(constant.MakeInt64(8), prog.Int32())
+	null := b.Const(nil, b.Prog.CIntPtr())
+	b.promise = null
+	id := b.CoID(align, null, null, null)
+	bf := b.Const(constant.MakeBool(false), prog.Bool())
+	b.CoSizeI32()
+	size := b.CoSizeI64()
+	b.CoAlignI32()
+	b.CoAlignI64()
+	b.CoAlloc(id)
+	frame := b.Alloca(size)
+	hdl := b.CoBegin(id, frame)
+
+	b.SetBlock(cleanBlk)
+	b.CoFree(id, frame)
+	b.Jump(suspdBlk)
+
+	b.SetBlock(suspdBlk)
+	b.CoEnd(hdl, bf, prog.TokenNone())
+	// b.Return(b.promise)
+
+	b.SetBlock(entryBlk)
+
+	b.CoResume(hdl)
+	b.CoDone(hdl)
+	b.CoDestroy(hdl)
+
+	b.CoPromise(null, align8, bf)
+	b.CoNoop()
+	b.CoFrame()
+	setArgs := types.NewTuple(types.NewVar(0, nil, "value", types.Typ[types.Int]))
+	setSig := types.NewSignatureType(nil, nil, nil, setArgs, nil, false)
+	setFn := pkg.NewFunc("setValue", setSig, InGo)
+	one := b.Const(constant.MakeInt64(1), prog.Int())
+
+	b.onSuspBlk = func(next BasicBlock) (BasicBlock, BasicBlock, BasicBlock) {
+		return suspdBlk, next, cleanBlk
+	}
+	b.CoYield(setFn, one, bf)
+	b.CoReturn(setFn, one)
+
+	assertPkg(t, pkg, `; ModuleID = 'foo/bar'
+source_filename = "foo/bar"
+
+define void @fn() {
+entry:
+  %0 = call token @llvm.coro.id(i32 0, ptr null, ptr null, ptr null)
+  %1 = call i32 @llvm.coro.size.i32()
+  %2 = call i64 @llvm.coro.size.i64()
+  %3 = call i32 @llvm.coro.align.i32()
+  %4 = call i64 @llvm.coro.align.i64()
+  %5 = call i1 @llvm.coro.alloc(token %0)
+  %6 = alloca i8, i64 %2, align 1
+  %7 = call ptr @llvm.coro.begin(token %0, ptr %6)
+  call void @llvm.coro.resume(ptr %7)
+  %8 = call i1 @llvm.coro.done(ptr %7)
+  %9 = zext i1 %8 to i64
+  %10 = trunc i64 %9 to i8
+  call void @llvm.coro.destroy(ptr %7)
+  %11 = call ptr @llvm.coro.promise(ptr null, i32 8, i1 false)
+  %12 = call ptr @llvm.coro.noop()
+  %13 = call ptr @llvm.coro.frame()
+  call void @setValue(ptr null, i64 1)
+  %14 = call i8 @llvm.coro.suspend(<null operand!>, i1 false)
+  switch i8 %14, label %suspend [
+    i8 0, label %suspend
+    i8 1, label %clean
+  ]
+
+suspend:                                          ; preds = %entry, %entry, %clean
+  %15 = call i1 @llvm.coro.end(ptr %7, i1 false, token none)
+  call void @setValue(ptr null, i64 1)
+  br label %clean
+
+clean:                                            ; preds = %suspend, %entry
+  %16 = call ptr @llvm.coro.free(token %0, ptr %6)
+  br label %suspend
+
+_llgo_3:                                          ; No predecessors!
+}
+
+; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: read)
+declare token @llvm.coro.id(i32, ptr readnone, ptr nocapture readonly, ptr)
+
+; Function Attrs: nounwind memory(none)
+declare i32 @llvm.coro.size.i32()
+
+; Function Attrs: nounwind memory(none)
+declare i64 @llvm.coro.size.i64()
+
+; Function Attrs: nounwind memory(none)
+declare i32 @llvm.coro.align.i32()
+
+; Function Attrs: nounwind memory(none)
+declare i64 @llvm.coro.align.i64()
+
+; Function Attrs: nounwind
+declare i1 @llvm.coro.alloc(token)
+
+; Function Attrs: nounwind
+declare ptr @llvm.coro.begin(token, ptr writeonly)
+
+; Function Attrs: nounwind memory(argmem: read)
+declare ptr @llvm.coro.free(token, ptr nocapture readonly)
+
+; Function Attrs: nounwind
+declare i1 @llvm.coro.end(ptr, i1, token)
+
+declare void @llvm.coro.resume(ptr)
+
+; Function Attrs: nounwind memory(argmem: readwrite)
+declare i1 @llvm.coro.done(ptr nocapture readonly)
+
+declare void @llvm.coro.destroy(ptr)
+
+; Function Attrs: nounwind memory(none)
+declare ptr @llvm.coro.promise(ptr nocapture, i32, i1)
+
+; Function Attrs: nounwind memory(none)
+declare ptr @llvm.coro.noop()
+
+; Function Attrs: nounwind memory(none)
+declare ptr @llvm.coro.frame()
+
+declare void @setValue(i64)
+
+; Function Attrs: nounwind
+declare i8 @llvm.coro.suspend(token, i1)
+
+`)
+}

ssa/stmt_builder.go

@@ -63,6 +63,13 @@ type aBuilder struct {
 	Func Function
 	Pkg  Package
 	Prog Program
+
+	async      bool
+	asyncToken Expr
+	promise    Expr
+	onSuspBlk  func(blk BasicBlock) (susp BasicBlock, next BasicBlock, clean BasicBlock)
+	onReturn   func()
+	blkOffset  int
 }
 
 // Builder represents a builder for creating instructions in a function.
@@ -94,7 +101,7 @@ func (b Builder) setBlockMoveLast(blk BasicBlock) (next BasicBlock) {
 
 	impl := b.impl
 
-	next = b.Func.MakeBlock()
+	next = b.Func.MakeBlock("")
 	impl.SetInsertPointAtEnd(next.last)
 	impl.Insert(last)
 
@@ -288,7 +295,7 @@ func (b Builder) Times(n Expr, loop func(i Expr)) {
 }
 
 // -----------------------------------------------------------------------------
-/*
+
 type caseStmt struct {
 	v   llvm.Value
 	blk llvm.BasicBlock
@@ -326,7 +333,7 @@ func (b Builder) Switch(v Expr, defb BasicBlock) Switch {
 	}
 	return &aSwitch{v.impl, defb.first, nil}
 }
-*/
+
 // -----------------------------------------------------------------------------
 
 // Phi represents a phi node.

ssa/type.go

@@ -58,6 +58,7 @@ const (
 	vkIface
 	vkStruct
 	vkChan
+	vkToken
 )
 
 // -----------------------------------------------------------------------------
@@ -282,6 +283,13 @@ func (p Program) tyInt() llvm.Type {
 	return p.intType
 }
 
+func (p Program) tyToken() llvm.Type {
+	if p.tokenType.IsNil() {
+		p.tokenType = p.ctx.TokenType()
+	}
+	return p.tokenType
+}
+
 func llvmIntType(ctx llvm.Context, size int) llvm.Type {
 	if size <= 4 {
 		return ctx.Int32Type()
@@ -362,6 +370,9 @@ func (p Program) toType(raw types.Type) Type {
 			return &aType{p.rtString(), typ, vkString}
 		case types.UnsafePointer:
 			return &aType{p.tyVoidPtr(), typ, vkPtr}
+		// TODO(lijie): temporary solution, should be replaced by a proper type
+		case types.Invalid:
+			return &aType{p.tyToken(), typ, vkInvalid}
 		}
 	case *types.Pointer:
 		elem := p.rawType(t.Elem())
@@ -444,7 +455,8 @@ func (p Program) toLLVMTypes(t *types.Tuple, n int) (ret []llvm.Type) {
 	if n > 0 {
 		ret = make([]llvm.Type, n)
 		for i := 0; i < n; i++ {
-			ret[i] = p.rawType(t.At(i).Type()).ll
+			pt := t.At(i)
+			ret[i] = p.rawType(pt.Type()).ll
 		}
 	}
 	return

x/async/_demo/asyncdemo/asyncdemo.go

@@ -0,0 +1,229 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"strings"
+	"time"
+
+	"github.com/goplus/llgo/x/async"
+	"github.com/goplus/llgo/x/tuple"
+)
+
+// -----------------------------------------------------------------------------
+
+func http(method string, url string, callback func(resp *Response, err error)) {
+	go func() {
+		body := ""
+		if strings.HasPrefix(url, "http://example.com/user/") {
+			name := url[len("http://example.com/user/"):]
+			body = `{"name":"` + name + `"}`
+		} else if strings.HasPrefix(url, "http://example.com/score/") {
+			body = "99.5"
+		}
+		time.Sleep(200 * time.Millisecond)
+		resp := &Response{StatusCode: 200, Body: body}
+		callback(resp, nil)
+	}()
+}
+
+// -----------------------------------------------------------------------------
+
+type Response struct {
+	StatusCode int
+
+	Body string
+}
+
+func (r *Response) Text() (co async.Promise[tuple.Tuple2[string, error]]) {
+	co.Return(tuple.Tuple2[string, error]{V1: r.Body, V2: nil})
+	return
+}
+
+//	async AsyncHttpGet(url string) (resp *Response, err error) {
+//	  http("GET", url, func(resp *Response, err error) {
+//	    return resp, err
+//	  })
+//	}
+func AsyncHttpGet(url string) (co async.Promise[tuple.Tuple2[*Response, error]]) {
+	return co.Async(func(resolve func(tuple.Tuple2[*Response, error])) {
+		http("GET", url, func(resp *Response, err error) {
+			resolve(tuple.Tuple2[*Response, error]{V1: resp, V2: nil})
+		})
+	})
+}
+
+func AsyncHttpPost(url string) (co async.Promise[tuple.Tuple2[*Response, error]]) {
+	http("POST", url, func(resp *Response, err error) {
+		// co.Return(tuple.Tuple2[*Response, error]{V1: resp, V2: nil})
+	})
+	co.Suspend()
+	return
+}
+
+// -----------------------------------------------------------------------------
+
+type User struct {
+	Name string
+}
+
+func GetUser(name string) (co async.Promise[tuple.Tuple2[User, error]]) {
+	resp, err := AsyncHttpGet("http://example.com/user/" + name).Await().Values()
+	if err != nil {
+		// return User{}, err
+		co.Return(tuple.Tuple2[User, error]{V1: User{}, V2: err})
+		return
+	}
+
+	if resp.StatusCode != 200 {
+		// return User{}, fmt.Errorf("http status code: %d", resp.StatusCode)
+		co.Return(tuple.Tuple2[User, error]{V1: User{}, V2: fmt.Errorf("http status code: %d", resp.StatusCode)})
+		return
+	}
+
+	body, err := resp.Text().Await().Values()
+	if err != nil {
+		// return User{}, err
+		co.Return(tuple.Tuple2[User, error]{V1: User{}, V2: err})
+		return
+	}
+	user := User{}
+	if err := json.Unmarshal([]byte(body), &user); err != nil {
+		// return User{}, err
+		co.Return(tuple.Tuple2[User, error]{V1: User{}, V2: err})
+		return
+	}
+
+	// return user, nil
+	co.Return(tuple.Tuple2[User, error]{V1: user, V2: nil})
+	return
+}
+
+func GetScore() (co *async.Promise[tuple.Tuple2[float64, error]]) {
+	resp, err := AsyncHttpGet("http://example.com/score/").Await().Values()
+	if err != nil {
+		co.Return(tuple.Tuple2[float64, error]{V1: 0, V2: err})
+		return
+	}
+
+	if resp.StatusCode != 200 {
+		// return 0, fmt.Errorf("http status code: %d", resp.StatusCode)
+		co.Return(tuple.Tuple2[float64, error]{V1: 0, V2: fmt.Errorf("http status code: %d", resp.StatusCode)})
+		return
+	}
+
+	body, err := resp.Text().Await().Values()
+	if err != nil {
+		// return 0, err
+		co.Return(tuple.Tuple2[float64, error]{V1: 0, V2: err})
+		return
+	}
+
+	score := 0.0
+	if _, err := fmt.Sscanf(body, "%f", &score); err != nil {
+		// return 0, err
+		co.Return(tuple.Tuple2[float64, error]{V1: 0, V2: err})
+		return
+	}
+
+	// return score, nil
+	co.Return(tuple.Tuple2[float64, error]{V1: score, V2: nil})
+	return
+}
+
+func DoUpdate(op string) (co *async.Promise[error]) {
+	resp, err := AsyncHttpPost("http://example.com/update/" + op).Await().Values()
+	if err != nil {
+		co.Return(err)
+		return
+	}
+
+	if resp.StatusCode != 200 {
+		co.Return(fmt.Errorf("http status code: %d", resp.StatusCode))
+	}
+
+	co.Return(nil)
+	return
+}
+
+func GenInts() (co *async.Promise[int]) {
+	co.Yield(3)
+	co.Yield(2)
+	co.Yield(5)
+	return
+}
+
+// Generator with async calls and panic
+func GenUsers() (co *async.Promise[User]) {
+	u, err := GetUser("Alice").Await().Values()
+	if err != nil {
+		panic(err)
+	}
+	co.Yield(u)
+	u, err = GetUser("Bob").Await().Values()
+	if err != nil {
+		panic(err)
+	}
+	co.Yield(u)
+	u, err = GetUser("Cindy").Await().Values()
+	if err != nil {
+		panic(err)
+	}
+	co.Yield(u)
+	log.Printf("genUsers done\n")
+	return
+}
+
+func Demo() (co *async.Promise[async.Void]) {
+	user, err := GetUser("1").Await().Values()
+	log.Println(user, err)
+
+	// user, err = naive.Race[tuple.Tuple2[User, error]](GetUser("2"), GetUser("3"), GetUser("4")).Value().Values()
+	// log.Println(user, err)
+
+	// users := naive.All[tuple.Tuple2[User, error]]([]naive.AsyncCall[tuple.Tuple2[User, error]]{GetUser("5"), GetUser("6"), GetUser("7")}).Value()
+	// log.Println(users, err)
+
+	// user, score, _ := naive.Await3Compiled[User, float64, async.Void](GetUser("8"), GetScore(), DoUpdate("update sth.")).Value().Values()
+	// log.Println(user, score, err)
+
+	// for loop with generator
+	g := GenInts()
+	for !g.Done() {
+		log.Println("genInt:", g.Value(), g.Done())
+		g.Resume()
+	}
+
+	// for loop with async generator
+	// for u, err := range GenUsers() {...}
+	g1 := GenUsers()
+	for !g1.Done() {
+		u := g1.Value()
+		log.Println("genUser:", u)
+		g1.Resume()
+	}
+
+	// TODO(lijie): select from multiple promises without channel
+	// select {
+	// case user := <-GetUser("123").Chan():
+	// 	log.Println("user:", user)
+	// case score := <-GetScore().Chan():
+	// 	log.Println("score:", score)
+	// case <-async.Timeout(5 * time.Second).Chan():
+	// 	log.Println("timeout")
+	// }
+
+	log.Println("Demo done")
+	co.Return(async.Void{})
+	return
+}
+
+func main() {
+	log.SetFlags(log.Lshortfile | log.LstdFlags)
+
+	log.Printf("=========== Run Demo ===========\n")
+	v1 := Demo()
+	log.Println(v1)
+	log.Printf("=========== Run Demo finished ===========\n")
+}

x/async/_demo/gendemo/gendemo.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/goplus/llgo/x/async"
+)
+
+func GenInts() (co *async.Promise[int]) {
+	println("gen: 1")
+	co.Yield(1)
+	println("gen: 2")
+	co.Yield(2)
+	println("gen: 3")
+	co.Yield(3)
+	return
+}
+
+func main() {
+	co := GenInts()
+	for !co.Done() {
+		fmt.Printf("got: %v\n", co.Value())
+		co.Next()
+	}
+	fmt.Printf("done\n")
+}

x/async/async.go

@@ -0,0 +1,77 @@
+/*
+ * 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 async
+
+import (
+	"unsafe"
+	_ "unsafe"
+)
+
+const (
+	LLGoPackage = "decl"
+)
+
+type Void = [0]byte
+
+// -----------------------------------------------------------------------------
+
+type Promise[TOut any] struct {
+	hdl   unsafe.Pointer
+	value TOut
+}
+
+// // llgo:link (*Promise).Await llgo.coAwait
+func (p *Promise[TOut]) Await() TOut {
+	panic("should not executed")
+}
+
+func (p *Promise[TOut]) Return(v TOut) {
+	p.value = v
+	coReturn(p.hdl)
+}
+
+// llgo:link (*Promise).Yield llgo.coYield
+func (p *Promise[TOut]) Yield(v TOut) {}
+
+// llgo:link (*Promise).Suspend llgo.coSuspend
+func (p *Promise[TOut]) Suspend() {}
+
+func (p *Promise[TOut]) Resume() {
+	coResume(p.hdl)
+}
+
+func (p *Promise[TOut]) Next() {
+	coResume(p.hdl)
+}
+
+// TODO(lijie): should merge to Yield()
+// call by llgo.coYield
+func (p *Promise[TOut]) setValue(v TOut) {
+	p.value = v
+}
+
+func (p *Promise[TOut]) Value() TOut {
+	return p.value
+}
+
+func (p *Promise[TOut]) Done() bool {
+	return coDone(p.hdl) != 0
+}
+
+func Run[TOut any](f func() TOut) TOut {
+	panic("should not executed")
+}

x/async/coro.go

@@ -0,0 +1,39 @@
+/*
+ * 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 async
+
+import (
+	"unsafe"
+	_ "unsafe"
+
+	"github.com/goplus/llgo/c"
+)
+
+// llgo:link coDone llgo.coDone
+func coDone(hdl unsafe.Pointer) c.Char {
+	panic("should not executed")
+}
+
+// llgo:link coResume llgo.coResume
+func coResume(hdl unsafe.Pointer) {
+	panic("should not executed")
+}
+
+// llgo:link coReturn llgo.coReturn
+func coReturn(hdl unsafe.Pointer) {
+	panic("should not executed")
+}

x/io/_demo/asyncdemo/async.go

@@ -1,290 +0,0 @@
-package main
-
-import (
-	"encoding/json"
-	"fmt"
-	"log"
-	"time"
-
-	"github.com/goplus/llgo/x/io"
-)
-
-// -----------------------------------------------------------------------------
-
-type Response struct {
-	StatusCode int
-
-	mockBody string
-}
-
-func (r *Response) mock(body string) {
-	r.mockBody = body
-}
-
-func (r *Response) Text() (resolve io.Promise[string]) {
-	resolve(r.mockBody, nil)
-	return
-}
-
-func (r *Response) TextCompiled() *io.PromiseImpl[string] {
-	P := &io.PromiseImpl[string]{}
-	P.Func = func(resolve func(string, error)) {
-		for {
-			switch P.Prev = P.Next; P.Prev {
-			case 0:
-				resolve(r.mockBody, nil)
-				P.Next = -1
-				return
-			default:
-				panic("Promise already done")
-			}
-		}
-	}
-	return P
-}
-
-func HttpGet(url string, callback func(resp *Response, err error)) {
-	resp := &Response{StatusCode: 200}
-	callback(resp, nil)
-}
-
-func AsyncHttpGet(url string) (resolve io.Promise[*Response]) {
-	HttpGet(url, resolve)
-	return
-}
-
-func AsyncHttpGetCompiled(url string) *io.PromiseImpl[*Response] {
-	P := &io.PromiseImpl[*Response]{}
-	P.Func = func(resolve func(*Response, error)) {
-		for {
-			switch P.Prev = P.Next; P.Prev {
-			case 0:
-				HttpGet(url, resolve)
-				P.Next = -1
-				return
-			default:
-				panic("Promise already done")
-			}
-		}
-	}
-	return P
-}
-
-// -----------------------------------------------------------------------------
-
-type User struct {
-	Name string
-}
-
-func GetUser(uid string) (resolve io.Promise[User]) {
-	resp, err := AsyncHttpGet("http://example.com/user/" + uid).Await()
-	if err != nil {
-		resolve(User{}, err)
-		return
-	}
-
-	if resp.StatusCode != 200 {
-		resolve(User{}, fmt.Errorf("http status code: %d", resp.StatusCode))
-		return
-	}
-
-	resp.mock(`{"name":"Alice"}`)
-
-	body, err := resp.Text().Await()
-	if err != nil {
-		resolve(User{}, err)
-		return
-	}
-	user := User{}
-	if err := json.Unmarshal([]byte(body), &user); err != nil {
-		resolve(User{}, err)
-		return
-	}
-
-	resolve(user, nil)
-	return
-}
-
-func GetUserCompiled(uid string) *io.PromiseImpl[User] {
-	var state1 *io.PromiseImpl[*Response]
-	var state2 *io.PromiseImpl[string]
-
-	P := &io.PromiseImpl[User]{}
-	P.Func = func(resolve func(User, error)) {
-		for {
-			switch P.Prev = P.Next; P.Prev {
-			case 0:
-				state1 = AsyncHttpGetCompiled("http://example.com/user/" + uid)
-				P.Next = 1
-				return
-			case 1:
-				state1.EnsureDone()
-				resp, err := state1.Value, state1.Err
-				if err != nil {
-					resolve(User{}, err)
-					return
-				}
-
-				if resp.StatusCode != 200 {
-					resolve(User{}, fmt.Errorf("http status code: %d", resp.StatusCode))
-					return
-				}
-
-				resp.mock(`{"name":"Alice"}`)
-
-				state2 = resp.TextCompiled()
-				P.Next = 2
-				return
-			case 2:
-				state2.EnsureDone()
-				body, err := state2.Value, state2.Err
-				if err != nil {
-					resolve(User{}, err)
-					return
-				}
-				user := User{}
-				if err := json.Unmarshal([]byte(body), &user); err != nil {
-					resolve(User{}, err)
-					return
-				}
-
-				resolve(user, nil)
-				P.Next = -1
-				return
-			default:
-				panic("Promise already done")
-			}
-		}
-	}
-	return P
-}
-
-func GetScore() *io.Promise[float64] {
-	panic("todo: GetScore")
-}
-
-func GetScoreCompiled() *io.PromiseImpl[float64] {
-	P := &io.PromiseImpl[float64]{}
-	P.Func = func(resolve func(float64, error)) {
-		for {
-			switch P.Prev = P.Next; P.Prev {
-			case 0:
-				panic("todo: GetScore")
-			default:
-				panic("Promise already done")
-			}
-		}
-	}
-	return P
-}
-
-func DoUpdate(op string) *io.Promise[io.Void] {
-	panic("todo: DoUpdate")
-}
-
-func DoUpdateCompiled(op string) *io.PromiseImpl[io.Void] {
-	P := &io.PromiseImpl[io.Void]{}
-	P.Func = func(resolve func(io.Void, error)) {
-		for {
-			switch P.Prev = P.Next; P.Prev {
-			case 0:
-				panic("todo: DoUpdate")
-			default:
-				panic("Promise already done")
-			}
-		}
-	}
-	return P
-}
-
-func Demo() (resolve io.Promise[io.Void]) {
-	user, err := GetUser("123").Await()
-	log.Println(user, err)
-
-	user, err = io.Race[User](GetUser("123"), GetUser("456"), GetUser("789")).Await()
-	log.Println(user, err)
-
-	users, err := io.All[User]([]io.AsyncCall[User]{GetUser("123"), GetUser("456"), GetUser("789")}).Await()
-	log.Println(users, err)
-
-	user, score, _, err := io.Await3[User, float64, io.Void](GetUser("123"), GetScore(), DoUpdate("update sth."))
-	log.Println(user, score, err)
-
-	// TODO(lijie): select from multiple promises without channel
-	select {
-	case user := <-GetUser("123").Chan():
-		log.Println("user:", user)
-	case score := <-GetScore().Chan():
-		log.Println("score:", score)
-	case <-io.Timeout(5 * time.Second).Chan():
-		log.Println("timeout")
-	}
-	return
-}
-
-func DemoCompiled() *io.PromiseImpl[io.Void] {
-	var state1 *io.PromiseImpl[User]
-	var state2 *io.PromiseImpl[User]
-	var state3 *io.PromiseImpl[[]User]
-	var state4 *io.PromiseImpl[io.Await3Result[User, float64, io.Void]]
-
-	P := &io.PromiseImpl[io.Void]{}
-	P.Func = func(resolve func(io.Void, error)) {
-		for {
-			switch P.Prev = P.Next; P.Prev {
-			case 0:
-				state1 = GetUserCompiled("123")
-				P.Next = 1
-				return
-			case 1:
-				state1.EnsureDone()
-				user, err := state1.Value, state1.Err
-				log.Printf("user: %v, err: %v\n", user, err)
-
-				state2 = io.Race[User](GetUserCompiled("123"), GetUserCompiled("456"), GetUserCompiled("789"))
-				P.Next = 2
-				return
-			case 2:
-				state2.EnsureDone()
-				user, err := state2.Value, state2.Err
-				log.Println(user, err)
-
-				state3 = io.All[User]([]io.AsyncCall[User]{GetUserCompiled("123"), GetUserCompiled("456"), GetUserCompiled("789")})
-				P.Next = 3
-				return
-			case 3:
-				state3.EnsureDone()
-				users, err := state3.Value, state3.Err
-				log.Println(users, err)
-
-				state4 = io.Await3Compiled[User, float64, io.Void](GetUserCompiled("123"), GetScoreCompiled(), DoUpdateCompiled("update sth."))
-				P.Next = 4
-				return
-			case 4:
-				state4.EnsureDone()
-				user, score, _, err := state4.Value.V1, state4.Value.V2, state4.Value.V3, state4.Value.Err
-				log.Println(user, score, err)
-
-				select {
-				case user := <-GetUserCompiled("123").Chan():
-					log.Println("user:", user)
-				case score := <-GetScoreCompiled().Chan():
-					log.Println("score:", score)
-				case <-io.TimeoutCompiled(5 * time.Second).Chan():
-					log.Println("timeout")
-				}
-				P.Next = -1
-				return
-			default:
-				panic("Promise already done")
-			}
-		}
-	}
-	return P
-}
-
-func main() {
-	log.SetFlags(log.Lshortfile | log.LstdFlags)
-	// io.Run(Demo())
-	io.Run(DemoCompiled())
-}

x/io/io.go

@@ -1,170 +0,0 @@
-/*
- * 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 io
-
-import (
-	_ "unsafe"
-
-	"time"
-)
-
-const (
-	LLGoPackage = "decl"
-)
-
-type Void = [0]byte
-
-// -----------------------------------------------------------------------------
-
-type AsyncCall[OutT any] interface {
-	Await(timeout ...time.Duration) (ret OutT, err error)
-	Chan() <-chan OutT
-	EnsureDone()
-}
-
-// llgo:link AsyncCall.Await llgo.await
-func Await[OutT any](call AsyncCall[OutT], timeout ...time.Duration) (ret OutT, err error) {
-	return
-}
-
-//go:linkname Timeout llgo.timeout
-func Timeout(time.Duration) (ret AsyncCall[Void])
-
-func TimeoutCompiled(d time.Duration) *PromiseImpl[Void] {
-	P := &PromiseImpl[Void]{}
-	P.Func = func(resolve func(Void, error)) {
-		go func() {
-			time.Sleep(d)
-			resolve(Void{}, nil)
-		}()
-	}
-	return P
-}
-
-// llgo:link Race llgo.race
-func Race[OutT any](acs ...AsyncCall[OutT]) (ret *PromiseImpl[OutT]) {
-	return
-}
-
-func All[OutT any](acs []AsyncCall[OutT]) (ret *PromiseImpl[[]OutT]) {
-	return nil
-}
-
-// llgo:link Await2 llgo.await
-func Await2[OutT1, OutT2 any](
-	ac1 AsyncCall[OutT1], ac2 AsyncCall[OutT2],
-	timeout ...time.Duration) (ret1 OutT1, ret2 OutT2, err error) {
-	return
-}
-
-type Await2Result[T1 any, T2 any] struct {
-	V1  T1
-	V2  T2
-	Err error
-}
-
-func Await2Compiled[OutT1, OutT2 any](
-	ac1 AsyncCall[OutT1], ac2 AsyncCall[OutT2],
-	timeout ...time.Duration) (ret *PromiseImpl[Await2Result[OutT1, OutT2]]) {
-	return
-}
-
-// llgo:link Await3 llgo.await
-func Await3[OutT1, OutT2, OutT3 any](
-	ac1 AsyncCall[OutT1], ac2 AsyncCall[OutT2], ac3 AsyncCall[OutT3],
-	timeout ...time.Duration) (ret1 OutT1, ret2 OutT2, ret3 OutT3, err error) {
-	return
-}
-
-type Await3Result[T1 any, T2 any, T3 any] struct {
-	V1  T1
-	V2  T2
-	V3  T3
-	Err error
-}
-
-func Await3Compiled[OutT1, OutT2, OutT3 any](
-	ac1 AsyncCall[OutT1], ac2 AsyncCall[OutT2], ac3 AsyncCall[OutT3],
-	timeout ...time.Duration) (ret *PromiseImpl[Await3Result[OutT1, OutT2, OutT3]]) {
-	return
-}
-
-func Run(ac AsyncCall[Void]) {
-	p := ac.(*PromiseImpl[Void])
-	p.Resume()
-	<-ac.Chan()
-}
-
-// -----------------------------------------------------------------------------
-
-type Promise[OutT any] func(OutT, error)
-
-// llgo:link Promise.Await llgo.await
-func (p Promise[OutT]) Await(timeout ...time.Duration) (ret OutT, err error) {
-	return
-}
-
-func (p Promise[OutT]) Chan() <-chan OutT {
-	return nil
-}
-
-func (p Promise[OutT]) EnsureDone() {
-
-}
-
-// -----------------------------------------------------------------------------
-
-type PromiseImpl[TOut any] struct {
-	Func  func(resolve func(TOut, error))
-	Value TOut
-	Err   error
-	Prev  int
-	Next  int
-
-	c chan TOut
-}
-
-func (p *PromiseImpl[TOut]) Resume() {
-	p.Func(func(v TOut, err error) {
-		p.Value = v
-		p.Err = err
-	})
-}
-
-func (p *PromiseImpl[TOut]) EnsureDone() {
-	if p.Next == -1 {
-		panic("Promise already done")
-	}
-}
-
-func (p *PromiseImpl[TOut]) Chan() <-chan TOut {
-	if p.c == nil {
-		p.c = make(chan TOut, 1)
-		p.Func(func(v TOut, err error) {
-			p.Value = v
-			p.Err = err
-			p.c <- v
-		})
-	}
-	return p.c
-}
-
-func (p *PromiseImpl[TOut]) Await(timeout ...time.Duration) (ret TOut, err error) {
-	panic("should not called")
-}
-
-// -----------------------------------------------------------------------------

x/tuple/tuple.go

@@ -0,0 +1,57 @@
+/*
+ * 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 tuple
+
+// -----------------------------------------------------------------------------
+
+type Tuple1[T any] struct {
+	V1 T
+}
+
+func (r Tuple1[T]) Values() T {
+	return r.V1
+}
+
+type Tuple2[T1 any, T2 any] struct {
+	V1 T1
+	V2 T2
+}
+
+func (r Tuple2[T1, T2]) Values() (T1, T2) {
+	return r.V1, r.V2
+}
+
+type Tuple3[T1 any, T2 any, T3 any] struct {
+	V1 T1
+	V2 T2
+	V3 T3
+}
+
+func (r Tuple3[T1, T2, T3]) Values() (T1, T2, T3) {
+	return r.V1, r.V2, r.V3
+}
+
+type Tuple4[T1 any, T2 any, T3 any, T4 any] struct {
+	V1 T1
+	V2 T2
+	V3 T3
+	V4 T4
+}
+
+func (r Tuple4[T1, T2, T3, T4]) Values() (T1, T2, T3, T4) {
+	return r.V1, r.V2, r.V3, r.V4
+}