Skip partially instantiated generics

compiler/function.go

@@ -249,6 +249,11 @@ func (c *compiler) generateFunctypes(p *packages.Package, f *ast.File, colors ma
 				}
 				for _, instance := range instances {
 					g := newGenericInstance(fn, instance)
+					if g.partial() {
+						// Skip instances where not all type params have concrete types.
+						// I'm not sure why these are generated in the SSA program.
+						continue
+					}
 					scope := &funcscope{vars: map[string]*funcvar{}}
 					name := g.gcshapePath()
 					collectFunctypes(p, name, instance.Syntax(), scope, colors, functypes, g)
@@ -430,6 +435,23 @@ func (g *genericInstance) typeOfParam(t types.Type) (types.Type, bool) {
 	return v, ok
 }
 
+func (g *genericInstance) partial() bool {
+	sig := g.instance.Signature
+	params := sig.Params()
+	for i := 0; i < params.Len(); i++ {
+		if _, ok := params.At(i).Type().(*types.TypeParam); ok {
+			return true
+		}
+	}
+	results := sig.Results()
+	for i := 0; i < results.Len(); i++ {
+		if _, ok := results.At(i).Type().(*types.TypeParam); ok {
+			return true
+		}
+	}
+	return false
+}
+
 func (g *genericInstance) scanRecvTypeArgs(fn func(*types.TypeParam, int, types.Type)) {
 	typeParams := g.recvType.TypeParams()
 	typeArgs := g.recvType.TypeArgs()

compiler/testdata/coroutine_durable.go

@@ -3255,7 +3255,7 @@ func IdentityGenericStructInt(n int) { (&IdentityGenericStruct[int]{n: n}).Run()
 
 //go:noinline
 func IdentityGenericClosure[T any](_fn0 T) {
-	_c := coroutine.LoadContext[T, any]()
+	_c := coroutine.LoadContext[int, any]()
 	var _f0 *struct {
 		IP int
 		X0 T
@@ -3443,10 +3443,5 @@ func init() {
 		F  uintptr
 		X0 int
 	}]("github.com/stealthrocket/coroutine/compiler/testdata.buildClosure[go.shape.int].func1")
-	_types.RegisterFunc[func(n T) func()]("github.com/stealthrocket/coroutine/compiler/testdata.buildClosure[go.shape.interface{}]")
-	_types.RegisterClosure[func(), struct {
-		F  uintptr
-		X0 T
-	}]("github.com/stealthrocket/coroutine/compiler/testdata.buildClosure[go.shape.interface{}].func1")
 	_types.RegisterFunc[func(_fn0 ...int)]("github.com/stealthrocket/coroutine/compiler/testdata.varArgs")
 }