misc/cgo/testcshared: add a c-shared test for android/arm.

- main3.c tests main.main is exported when compiled for GOOS=android.
- wait longer for main2.c (it's slow on android/arm)
- rearranged test.bash

Fixes #10070.

Change-Id: I6e5a98d1c5fae776afa54ecb5da633b59b269316
Reviewed-on: https://go-review.googlesource.com/9296
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>

misc/cgo/testcshared/main2.c

@@ -21,7 +21,7 @@ int main(void) {
 
   // The descriptor will be initialized in a thread, so we have to
   // give a chance to get opened.
-  for (i = 0; i < 10; i++) {
+  for (i = 0; i < 100; i++) {
     n = read(fd, buf, sizeof buf);
     if (n >= 0)
       break;

misc/cgo/testcshared/main3.c

@@ -0,0 +1,29 @@
+// 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.
+
+#include <stdint.h>
+#include <stdio.h>
+#include <dlfcn.h>
+
+// Tests "main.main" is exported on android/arm,
+// which golang.org/x/mobile/app depends on.
+int main(int argc, char** argv) {
+  void* handle = dlopen(argv[1], RTLD_LAZY | RTLD_GLOBAL);
+  if (!handle) {
+    fprintf(stderr, "ERROR: failed to open the shared library: %s\n",
+            dlerror());
+    return 2;
+  }
+
+  uintptr_t main_fn = (uintptr_t)dlsym(handle, "main.main");
+  if (!main_fn) {
+    fprintf(stderr, "ERROR: missing main.main: %s\n", dlerror());
+    return 2;
+  }
+
+  // TODO(hyangah): check that main.main can run.
+
+  printf("PASS\n");
+  return 0;
+}

misc/cgo/testcshared/src/libgo/libgo.go

@@ -23,7 +23,6 @@ func init() {
 
 func main() {
 	ranMain = true
-	panic("FAIL: main ran")
 }
 
 //export DidInitRun

misc/cgo/testcshared/test.bash

@@ -3,37 +3,98 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
+# For testing Android, this script requires adb to push and run compiled
+# binaries on a target device.
+
 set -e
 
+if [ ! -f src/libgo/libgo.go ]; then
+	cwd=$(pwd)
+	echo 'misc/cgo/testcshared/test.bash is running in $cwd' 1>&2
+	exit 1
+fi
+
+goos=$(go env GOOS)
+
+# Temporary directory on the android device.
+androidpath=/data/local/tmp/testcshared-$$
+
 function cleanup() {
-	rm -f libgo.so libgo2.so testp testp2
+	rm -f libgo.so libgo2.so testp testp2 testp3
+
+	if [ "$(go env GOOS)" == "android" ]; then
+		adb shell rm -rf $androidpath
+	fi
 }
 trap cleanup EXIT
 
+if [ "$goos" == "android" ]; then
+	adb shell mkdir -p "$androidpath"
+fi
+
+function run() {
+	case "$goos" in
+	"android")
+		local args=$@
+		for ((i=0; i < ${#args}; i++)); do
+			args[$i]=${args[$i]//.\//${androidpath}\/}
+			args[$i]=${args[$i]//=./=${androidpath}}
+		done
+		echo $(adb shell ${args} | tr -d '\r')
+		;;
+	*)
+		echo $(env $@)
+		;;
+	esac
+}
+
+function binpush() {
+	bin=${1}
+	if [ "$goos" == "android" ]; then
+		adb push "$bin"  "${androidpath}/${bin}" 2>/dev/null
+	fi
+}
+
 GOPATH=$(pwd) go build -buildmode=c-shared -o libgo.so src/libgo/libgo.go
+binpush libgo.so
 
+# test0: exported symbols in shared lib are accessible.
 $(go env CC) $(go env GOGCCFLAGS) -o testp main0.c libgo.so
-output=$(LD_LIBRARY_PATH=$LD_LIBRARY_PATH:. ./testp)
-# testp prints PASS at the end of its execution.
+binpush testp
+output=$(run LD_LIBRARY_PATH=. ./testp)
 if [ "$output" != "PASS" ]; then
-	echo "FAIL: got $output"
+	echo "FAIL test0 got ${output}"
 	exit 1
 fi
 
+# test1: .so can be dynamically loaded and exported symbols are accessible.
 $(go env CC) $(go env GOGCCFLAGS) -o testp main1.c -ldl
-output=$(./testp ./libgo.so) 
-# testp prints PASS at the end of its execution.
+binpush testp
+output=$(run ./testp ./libgo.so)
 if [ "$output" != "PASS" ]; then
-	echo "FAIL: got $output"
+	echo "FAIL test1 got ${output}"
 	exit 1
 fi
 
+# test2: tests libgo2.so which does not export any functions.
 GOPATH=$(pwd) go build -buildmode=c-shared -o libgo2.so src/libgo2/libgo2.go
-
+binpush libgo2.so
 $(go env CC) $(go env GOGCCFLAGS) -o testp2 main2.c -Wl,--no-as-needed libgo2.so
-output=$(LD_LIBRARY_PATH=$LD_LIBRARY_PATH:. ./testp2)
-# testp2 prints PASS at the end of its execution.
+binpush testp2
+output=$(run LD_LIBRARY_PATH=. ./testp2)
 if [ "$output" != "PASS" ]; then
-	echo "FAIL: got $output"
+	echo "FAIL test2 got ${output}"
 	exit 1
 fi
+
+# test3: tests main.main is exported on android.
+if [ "$goos" == "android" ]; then
+	$(go env CC) $(go env GOGCCFLAGS) -o testp3 main3.c -ldl
+	binpush testp3
+	output=$(run ./testp ./libgo.so)
+	if [ "$output" != "PASS" ]; then
+		echo "FAIL test3 got ${output}"
+		exit 1
+	fi
+fi
+echo "ok"

src/cmd/dist/test.go

@@ -383,26 +383,25 @@ func (t *tester) extLink() bool {
 }
 
 func (t *tester) buildmode(mode string) bool {
+	pair := t.goos + "-" + t.goarch
 	switch mode {
 	case "c-archive":
-		switch {
-		case !t.extLink():
-			return false
-		case t.goos == "darwin":
-			switch t.goarch {
-			case "amd64", "arm", "arm64":
-				return true
-			default:
-				return false
-			}
-		case t.goos == "linux" && (t.goarch == "amd64" || t.goarch == "386"):
-			return true
-		default:
+		if !t.extLink() {
 			return false
 		}
+		switch pair {
+		case "darwin-amd64", "darwin-arm", "darwin-arm64",
+			"linux-amd64", "linux-386":
+			return true
+		}
+		return false
 	case "c-shared":
-		// TODO(hyangah): add linux/386.
-		return t.goos == "linux" && t.goarch == "amd64"
+		// TODO(hyangah): add linux-386.
+		switch pair {
+		case "linux-amd64", "android-arm":
+			return true
+		}
+		return false
 	default:
 		log.Fatal("internal error: unknown buildmode %s", mode)
 		return false