misc/cgo/test,cmd/dist: enable (most) Cgo tests on Android

Some tests cannot build for Android; use build tags and stubs to
skip them.

For #15919

Change-Id: Ieedcb73d4cabe23c3775cfb1d44c1276982dccd9
Reviewed-on: https://go-review.googlesource.com/23634
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>

misc/cgo/test/cgo_stubs_android_test.go

+// Copyright 2012 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 cgotest
+
+import "testing"
+
+// Stubs for tests that fails to build on Android
+func test6997(t *testing.T)        {}
+func test3775(t *testing.T)        {}
+func test8694(t *testing.T)        {}
+func testSigaltstack(t *testing.T) {}

misc/cgo/test/issue3775.go

+// +build !android
+
 package cgotest
 
 /*

misc/cgo/test/issue6997_linux.c

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build !android
+
 #include <pthread.h>
 #include <stdio.h>
 #include <unistd.h>

misc/cgo/test/issue6997_linux.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build !android
+
 // Test that pthread_cancel works as expected
 // (NPTL uses SIGRTMIN to implement thread cancelation)
 // See https://golang.org/issue/6997

misc/cgo/test/issue7978.go

@@ -103,6 +103,9 @@ func test7978(t *testing.T) {
 	if C.HAS_SYNC_FETCH_AND_ADD == 0 {
 		t.Skip("clang required for __sync_fetch_and_add support on darwin/arm")
 	}
+	if runtime.GOOS == "android" {
+		t.Skip("GOTRACEBACK is not passed on to the exec wrapper")
+	}
 	if os.Getenv("GOTRACEBACK") != "2" {
 		t.Fatalf("GOTRACEBACK must be 2")
 	}

misc/cgo/test/issue8694.go

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build !android
+
 package cgotest
 
 /*

misc/cgo/test/sigaltstack.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !windows
+// +build !windows,!android
 
 // Test that the Go runtime still works if C code changes the signal stack.
 

src/cmd/dist/test.go

@@ -432,8 +432,8 @@ func (t *tester) registerTests() {
 		},
 	})
 
-	if t.cgoEnabled && t.goos != "android" && !t.iOS() {
-		// Disabled on android and iOS. golang.org/issue/8345
+	if t.cgoEnabled && !t.iOS() {
+		// Disabled on iOS. golang.org/issue/15919
 		t.tests = append(t.tests, distTest{
 			name:    "cgo_stdio",
 			heading: "../misc/cgo/stdio",
@@ -465,9 +465,9 @@ func (t *tester) registerTests() {
 			})
 		}
 	}
-	if t.cgoEnabled && t.goos != "android" && !t.iOS() {
-		// TODO(crawshaw): reenable on android and iOS
-		// golang.org/issue/8345
+	if t.cgoEnabled && !t.iOS() {
+		// TODO(crawshaw): reenable on iOS
+		// golang.org/issue/15919
 		//
 		// These tests are not designed to run off the host.
 		t.tests = append(t.tests, distTest{
@@ -729,7 +729,7 @@ func (t *tester) runHostTest(dirBanner, pkg string) error {
 func (t *tester) cgoTest(dt *distTest) error {
 	env := mergeEnvLists([]string{"GOTRACEBACK=2"}, os.Environ())
 
-	if t.goos == "android" || t.iOS() {
+	if t.iOS() {
 		cmd := t.dirCmd("misc/cgo/test", "go", "test", t.tags())
 		cmd.Env = env
 		return cmd.Run()
@@ -738,7 +738,7 @@ func (t *tester) cgoTest(dt *distTest) error {
 	cmd := t.addCmd(dt, "misc/cgo/test", "go", "test", t.tags(), "-ldflags", "-linkmode=auto", t.runFlag(""))
 	cmd.Env = env
 
-	if t.gohostos != "dragonfly" && t.gohostarch != "ppc64le" {
+	if t.gohostos != "dragonfly" && t.gohostarch != "ppc64le" && t.goos != "android" {
 		// linkmode=internal fails on dragonfly since errno is a TLS relocation.
 		// linkmode=internal fails on ppc64le because cmd/link doesn't
 		// handle the TOC correctly (issue 15409).
@@ -792,8 +792,10 @@ func (t *tester) cgoTest(dt *distTest) error {
 			if err := cmd.Run(); err != nil {
 				fmt.Println("No support for static linking found (lacks libc.a?), skip cgo static linking test.")
 			} else {
+				if t.goos != "android" {
 					cmd = t.addCmd(dt, "misc/cgo/testtls", "go", "test", "-ldflags", `-linkmode=external -extldflags "-static -pthread"`)
 					cmd.Env = env
+				}
 
 				cmd = t.addCmd(dt, "misc/cgo/nocgo", "go", "test")
 				cmd.Env = env
@@ -801,9 +803,11 @@ func (t *tester) cgoTest(dt *distTest) error {
 				cmd = t.addCmd(dt, "misc/cgo/nocgo", "go", "test", "-ldflags", `-linkmode=external`)
 				cmd.Env = env
 
+				if t.goos != "android" {
 					cmd = t.addCmd(dt, "misc/cgo/nocgo", "go", "test", "-ldflags", `-linkmode=external -extldflags "-static -pthread"`)
 					cmd.Env = env
 				}
+			}
 
 			if pair != "freebsd-amd64" { // clang -pie fails to link misc/cgo/test
 				cmd := t.dirCmd("misc/cgo/test",