add a test that structures pack. 6g fails.
R=rsc
CC=golang-dev
https://golang.org/cl/237041
diff --git a/test/bugs/bug260.go b/test/bugs/bug260.go
new file mode 100644
index 0000000..cbdd148
--- /dev/null
+++ b/test/bugs/bug260.go
@@ -0,0 +1,41 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// Test that structures pack densely, according to the alignment of the largest field.
+
+package main
+
+import (
+ "fmt"
+ "os"
+ "strconv"
+)
+
+type T1 struct { x uint8 }
+type T2 struct { x uint16 }
+type T4 struct { x uint32 }
+
+func main() {
+ status := 0
+ var b1 [10]T1
+ a0, _ := strconv.Btoui64(fmt.Sprintf("%p", &b1[0])[2:], 16)
+ a1, _ := strconv.Btoui64(fmt.Sprintf("%p", &b1[1])[2:], 16)
+ if a1 != a0 + 1 {
+ fmt.Println("FAIL: alignment should be 1, is", a1-a0)
+ status = 1
+ }
+ var b2 [10]T2
+ a0, _ = strconv.Btoui64(fmt.Sprintf("%p", &b2[0])[2:], 16)
+ a1, _ = strconv.Btoui64(fmt.Sprintf("%p", &b2[1])[2:], 16)
+ if a1 != a0 + 2 {
+ fmt.Println("FAIL: alignment should be 2, is", a1-a0)
+ status = 1
+ }
+ var b4 [10]T4
+ a0, _ = strconv.Btoui64(fmt.Sprintf("%p", &b4[0])[2:], 16)
+ a1, _ = strconv.Btoui64(fmt.Sprintf("%p", &b4[1])[2:], 16)
+ if a1 != a0 + 4 {
+ fmt.Println("FAIL: alignment should be 4, is", a1-a0)
+ status = 1
+ }
+ os.Exit(status)
+}
