Initial commit: Go 1.23 release state

test/stack.go

@@ -0,0 +1,100 @@
+// run
+
+// Copyright 2009 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.
+
+// Test stack splitting code.
+// Try to tickle stack splitting bugs by doing
+// go, defer, and closure calls at different stack depths.
+
+package main
+
+type T [20]int
+
+func g(c chan int, t T) {
+	s := 0
+	for i := 0; i < len(t); i++ {
+		s += t[i]
+	}
+	c <- s
+}
+
+func d(t T) {
+	s := 0
+	for i := 0; i < len(t); i++ {
+		s += t[i]
+	}
+	if s != len(t) {
+		println("bad defer", s)
+		panic("fail")
+	}
+}
+
+func f0() {
+	// likely to make a new stack for f0,
+	// because the call to f1 puts 3000 bytes
+	// in our frame.
+	f1()
+}
+
+func f1() [3000]byte {
+	// likely to make a new stack for f1,
+	// because 3000 bytes were used by f0
+	// and we need 3000 more for the call
+	// to f2.  if the call to morestack in f1
+	// does not pass the frame size, the new
+	// stack (default size 5k) will not be big
+	// enough for the frame, and the morestack
+	// check in f2 will die, if we get that far 
+	// without faulting.
+	f2()
+	return [3000]byte{}
+}
+
+func f2() [3000]byte {
+	// just take up space
+	return [3000]byte{}
+}
+
+var c = make(chan int)
+var t T
+var b = []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+
+func recur(n int) {
+	ss := string(b)
+	if len(ss) != len(b) {
+		panic("bad []byte -> string")
+	}
+	go g(c, t)
+	f0()
+	s := <-c
+	if s != len(t) {
+		println("bad go", s)
+		panic("fail")
+	}
+	f := func(t T) int {
+		s := 0
+		for i := 0; i < len(t); i++ {
+			s += t[i]
+		}
+		s += n
+		return s
+	}
+	s = f(t)
+	if s != len(t)+n {
+		println("bad func", s, "at level", n)
+		panic("fail")
+	}
+	if n > 0 {
+		recur(n - 1)
+	}
+	defer d(t)
+}
+
+func main() {
+	for i := 0; i < len(t); i++ {
+		t[i] = 1
+	}
+	recur(8000)
+}