diff --git a/src/cmd/compile/internal/inline/inl.go b/src/cmd/compile/internal/inline/inl.go index 1b1a9cf338..84a13e5796 100644 --- a/src/cmd/compile/internal/inline/inl.go +++ b/src/cmd/compile/internal/inline/inl.go @@ -1033,6 +1033,28 @@ func canInlineCallExpr(callerfn *ir.Func, n *ir.CallExpr, callee *ir.Func, bigCa return false, 0, false } } + do := func(fn *ir.Func) bool { + // Can't recursively inline a function if the function body contains + // a call to a function f, which the function f is one of the call arguments. + return ir.Any(fn, func(node ir.Node) bool { + if call, ok := node.(*ir.CallExpr); ok { + for _, arg := range call.Args { + if call.Fun == arg { + return true + } + } + } + return false + }) + } + for _, fn := range []*ir.Func{callerfn, callee} { + if do(fn) { + if log && logopt.Enabled() { + logopt.LogOpt(n.Pos(), "cannotInlineCall", "inline", fmt.Sprintf("recursive call to function: %s", ir.FuncName(fn))) + } + return false, 0, false + } + } if base.Flag.Cfg.Instrumenting && types.IsNoInstrumentPkg(callee.Sym().Pkg) { // Runtime package must not be instrumented. diff --git a/test/fixedbugs/issue72063.go b/test/fixedbugs/issue72063.go new file mode 100644 index 0000000000..7b9c13e452 --- /dev/null +++ b/test/fixedbugs/issue72063.go @@ -0,0 +1,40 @@ +// run + +// Copyright 2025 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package main + +import "fmt" + +// Y is the Y-combinator based on https://dreamsongs.com/Files/WhyOfY.pdf +func Y[Endo ~func(RecFct) RecFct, RecFct ~func(T) R, T, R any](f Endo) RecFct { + + type internal[RecFct ~func(T) R, T, R any] func(internal[RecFct, T, R]) RecFct + + g := func(h internal[RecFct, T, R]) RecFct { + return func(t T) R { + return f(h(h))(t) + } + } + return g(g) +} + +func main() { + + fct := Y(func(r func(int) int) func(int) int { + return func(n int) int { + if n <= 0 { + return 1 + } + return n * r(n-1) + } + }) + + want := 3628800 + if got := fct(10); got != want { + msg := fmt.Sprintf("unexpected result, got: %d, want: %d", got, want) + panic(msg) + } +}