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-rw-r--r--test/fixedbugs/issue5373.go71
1 files changed, 71 insertions, 0 deletions
diff --git a/test/fixedbugs/issue5373.go b/test/fixedbugs/issue5373.go
new file mode 100644
index 0000000..8aee9a2
--- /dev/null
+++ b/test/fixedbugs/issue5373.go
@@ -0,0 +1,71 @@
+// run
+
+// 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.
+
+// Ensure that zeroing range loops have the requisite side-effects.
+
+package main
+
+import (
+ "fmt"
+ "os"
+)
+
+func check(n int) {
+ // When n == 0, i is untouched by the range loop.
+ // Picking an initial value of -1 for i makes the
+ // "want" calculation below correct in all cases.
+ i := -1
+ s := make([]byte, n)
+ for i = range s {
+ s[i] = 0
+ }
+ if want := n - 1; i != want {
+ fmt.Printf("index after range with side-effect = %d want %d\n", i, want)
+ os.Exit(1)
+ }
+
+ i = n + 1
+ // i is shadowed here, so its value should be unchanged.
+ for i := range s {
+ s[i] = 0
+ }
+ if want := n + 1; i != want {
+ fmt.Printf("index after range without side-effect = %d want %d\n", i, want)
+ os.Exit(1)
+ }
+
+ // Index variable whose evaluation has side-effects
+ var x int
+ f := func() int {
+ x++
+ return 0
+ }
+ var a [1]int
+ for a[f()] = range s {
+ s[a[f()]] = 0
+ }
+ if want := n * 2; x != want {
+ fmt.Printf("index function calls = %d want %d\n", x, want)
+ os.Exit(1)
+ }
+
+ // Range expression whose evaluation has side-effects
+ x = 0
+ b := [1][]byte{s}
+ for i := range b[f()] {
+ b[f()][i] = 0
+ }
+ if want := n + 1; x != n+1 {
+ fmt.Printf("range expr function calls = %d want %d\n", x, want)
+ os.Exit(1)
+ }
+}
+
+func main() {
+ check(0)
+ check(1)
+ check(15)
+}