test: silence/coalesce some tests

Add copyright notice to nilptr.go.

R=golang-dev, r
CC=golang-dev
http://codereview.appspot.com/5139048

1 files changed, 170 insertions, 0 deletions

diff --git a/test/cmp.go b/test/cmp.go
new file mode 100644
index 000000000..570487db6
--- /dev/null
+++ b/test/cmp.go
@@ -0,0 +1,170 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// 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.
+
+package main
+
+import "unsafe"
+
+func use(bool) {}
+
+func stringptr(s string) uintptr { return *(*uintptr)(unsafe.Pointer(&s)) }
+
+func isfalse(b bool) {
+	if b {
+		// stack will explain where
+		panic("wanted false, got true")
+	}
+}
+
+func istrue(b bool) {
+	if !b {
+		// stack will explain where
+		panic("wanted true, got false")
+	}
+}
+
+type T *int
+
+func main() {
+	var a []int
+	var b map[string]int
+
+	var c string = "hello"
+	var d string = "hel" // try to get different pointer
+	d = d + "lo"
+	if stringptr(c) == stringptr(d) {
+		panic("compiler too smart -- got same string")
+	}
+
+	var e = make(chan int)
+
+	var ia interface{} = a
+	var ib interface{} = b
+	var ic interface{} = c
+	var id interface{} = d
+	var ie interface{} = e
+
+	// these comparisons are okay because
+	// string compare is okay and the others
+	// are comparisons where the types differ.
+	isfalse(ia == ib)
+	isfalse(ia == ic)
+	isfalse(ia == id)
+	isfalse(ib == ic)
+	isfalse(ib == id)
+	istrue(ic == id)
+	istrue(ie == ie)
+	
+	// these are okay because one side of the
+	// comparison need only be assignable to the other.
+	isfalse(a == ib)
+	isfalse(a == ic)
+	isfalse(a == id)
+	isfalse(b == ic)
+	isfalse(b == id)
+	istrue(c == id)
+	istrue(e == ie)
+
+	isfalse(ia == b)
+	isfalse(ia == c)
+	isfalse(ia == d)
+	isfalse(ib == c)
+	isfalse(ib == d)
+	istrue(ic == d)
+	istrue(ie == e)
+
+	// 6g used to let this go through as true.
+	var g uint64 = 123
+	var h int64 = 123
+	var ig interface{} = g
+	var ih interface{} = h
+	isfalse(ig == ih)
+
+	// map of interface should use == on interface values,
+	// not memory.
+	// TODO: should m[c], m[d] be valid here?
+	var m = make(map[interface{}]int)
+	m[ic] = 1
+	m[id] = 2
+	if m[ic] != 2 {
+		println("m[ic] = ", m[ic])
+		panic("bad m[ic]")
+	}
+	
+	// non-interface comparisons
+	{
+		c := make(chan int)
+		c1 := (<-chan int)(c)
+		c2 := (chan<- int)(c)
+		istrue(c == c1)
+		istrue(c == c2)
+		istrue(c1 == c)
+		istrue(c2 == c)
+		
+		d := make(chan int)
+		isfalse(c == d)
+		isfalse(d == c)
+		isfalse(d == c1)
+		isfalse(d == c2)
+		isfalse(c1 == d)
+		isfalse(c2 == d)
+	}
+
+	// named types vs not
+	{
+		var x = new(int)
+		var y T
+		var z T = x
+		
+		isfalse(x == y)
+		istrue(x == z)
+		isfalse(y == z)
+
+		isfalse(y == x)
+		istrue(z == x)
+		isfalse(z == y)
+	}
+	
+	shouldPanic(p1)
+	shouldPanic(p2)
+	shouldPanic(p3)
+	shouldPanic(p4)
+}
+
+func p1() {
+	var a []int
+	var ia interface{} = a
+	use(ia == ia)
+}
+
+func p2() {
+	var b []int
+	var ib interface{} = b
+	use(ib == ib)
+}
+
+func p3() {
+	var a []int
+	var ia interface{} = a
+	var m = make(map[interface{}] int)
+	m[ia] = 1
+}
+
+func p4() {
+	var b []int
+	var ib interface{} = b
+	var m = make(map[interface{}] int)
+	m[ib] = 1
+}
+
+func shouldPanic(f func()) {
+	defer func() {
+		if recover() == nil {
+			panic("function should panic")
+		}
+	}()
+	f()
+}