Initial commit: Go 1.23 release state

test/fixedbugs/issue13799.go

@@ -0,0 +1,191 @@
+// errorcheck -0 -m -l
+
+// Copyright 2015 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, using compiler diagnostic flags, that the escape analysis is working.
+// Compiles but does not run.  Inlining is disabled.
+// Registerization is disabled too (-N), which should
+// have no effect on escape analysis.
+
+package main
+
+import "fmt"
+
+func main() {
+	// Just run test over and over again. This main func is just for
+	// convenience; if test were the main func, we could also trigger
+	// the panic just by running the program over and over again
+	// (sometimes it takes 1 time, sometimes it takes ~4,000+).
+	for iter := 0; ; iter++ {
+		if iter%50 == 0 {
+			fmt.Println(iter) // ERROR "iter escapes to heap$" "... argument does not escape$"
+		}
+		test1(iter)
+		test2(iter)
+		test3(iter)
+		test4(iter)
+		test5(iter)
+		test6(iter)
+	}
+}
+
+func test1(iter int) {
+
+	const maxI = 500
+	m := make(map[int][]int) // ERROR "make\(map\[int\]\[\]int\) escapes to heap$"
+
+	// The panic seems to be triggered when m is modified inside a
+	// closure that is both recursively called and reassigned to in a
+	// loop.
+
+	// Cause of bug -- escape of closure failed to escape (shared) data structures
+	// of map.  Assign to fn declared outside of loop triggers escape of closure.
+	// Heap -> stack pointer eventually causes badness when stack reallocation
+	// occurs.
+
+	var fn func() // ERROR "moved to heap: fn$"
+	i := 0        // ERROR "moved to heap: i$"
+	for ; i < maxI; i++ {
+		// var fn func() // this makes it work, because fn stays off heap
+		j := 0        // ERROR "moved to heap: j$"
+		fn = func() { // ERROR "func literal escapes to heap$"
+			m[i] = append(m[i], 0)
+			if j < 25 {
+				j++
+				fn()
+			}
+		}
+		fn()
+	}
+
+	if len(m) != maxI {
+		panic(fmt.Sprintf("iter %d: maxI = %d, len(m) = %d", iter, maxI, len(m))) // ERROR "iter escapes to heap$" "len\(m\) escapes to heap$" "500 escapes to heap$" "... argument does not escape$" "fmt.Sprintf\(.*\) escapes to heap"
+	}
+}
+
+func test2(iter int) {
+
+	const maxI = 500
+	m := make(map[int][]int) // ERROR "make\(map\[int\]\[\]int\) does not escape$"
+
+	// var fn func()
+	for i := 0; i < maxI; i++ {
+		var fn func() // this makes it work, because fn stays off heap
+		j := 0
+		fn = func() { // ERROR "func literal does not escape$"
+			m[i] = append(m[i], 0)
+			if j < 25 {
+				j++
+				fn()
+			}
+		}
+		fn()
+	}
+
+	if len(m) != maxI {
+		panic(fmt.Sprintf("iter %d: maxI = %d, len(m) = %d", iter, maxI, len(m))) // ERROR "iter escapes to heap$" "len\(m\) escapes to heap$" "500 escapes to heap$" "... argument does not escape$" "fmt.Sprintf\(.*\) escapes to heap"
+	}
+}
+
+func test3(iter int) {
+
+	const maxI = 500
+	var x int // ERROR "moved to heap: x$"
+	m := &x
+
+	var fn func() // ERROR "moved to heap: fn$"
+	for i := 0; i < maxI; i++ {
+		// var fn func() // this makes it work, because fn stays off heap
+		j := 0        // ERROR "moved to heap: j$"
+		fn = func() { // ERROR "func literal escapes to heap$"
+			if j < 100 {
+				j++
+				fn()
+			} else {
+				*m = *m + 1
+			}
+		}
+		fn()
+	}
+
+	if *m != maxI {
+		panic(fmt.Sprintf("iter %d: maxI = %d, *m = %d", iter, maxI, *m)) // ERROR "\*m escapes to heap$" "iter escapes to heap$" "500 escapes to heap$" "... argument does not escape$" "fmt.Sprintf\(.*\) escapes to heap"
+	}
+}
+
+func test4(iter int) {
+
+	const maxI = 500
+	var x int
+	m := &x
+
+	// var fn func()
+	for i := 0; i < maxI; i++ {
+		var fn func() // this makes it work, because fn stays off heap
+		j := 0
+		fn = func() { // ERROR "func literal does not escape$"
+			if j < 100 {
+				j++
+				fn()
+			} else {
+				*m = *m + 1
+			}
+		}
+		fn()
+	}
+
+	if *m != maxI {
+		panic(fmt.Sprintf("iter %d: maxI = %d, *m = %d", iter, maxI, *m)) // ERROR "\*m escapes to heap$" "iter escapes to heap$" "500 escapes to heap$" "... argument does not escape$" "fmt.Sprintf\(.*\) escapes to heap"
+	}
+}
+
+type str struct {
+	m *int
+}
+
+func recur1(j int, s *str) { // ERROR "s does not escape"
+	if j < 100 {
+		j++
+		recur1(j, s)
+	} else {
+		*s.m++
+	}
+}
+
+func test5(iter int) {
+
+	const maxI = 500
+	var x int // ERROR "moved to heap: x$"
+	m := &x
+
+	var fn *str
+	for i := 0; i < maxI; i++ {
+		// var fn *str // this makes it work, because fn stays off heap
+		fn = &str{m} // ERROR "&str{...} escapes to heap"
+		recur1(0, fn)
+	}
+
+	if *m != maxI {
+		panic(fmt.Sprintf("iter %d: maxI = %d, *m = %d", iter, maxI, *m)) // ERROR "\*m escapes to heap$" "iter escapes to heap$" "500 escapes to heap$" "... argument does not escape$" "fmt.Sprintf\(.*\) escapes to heap"
+	}
+}
+
+func test6(iter int) {
+
+	const maxI = 500
+	var x int
+	m := &x
+
+	// var fn *str
+	for i := 0; i < maxI; i++ {
+		var fn *str  // this makes it work, because fn stays off heap
+		fn = &str{m} // ERROR "&str{...} does not escape"
+		recur1(0, fn)
+	}
+
+	if *m != maxI {
+		panic(fmt.Sprintf("iter %d: maxI = %d, *m = %d", iter, maxI, *m)) // ERROR "\*m escapes to heap$" "iter escapes to heap$" "500 escapes to heap$" "... argument does not escape$" "fmt.Sprintf\(.*\) escapes to heap"
+	}
+}