Add a sample to demonstrate module exports in the NDK.

+ add .gitignore

Change-Id: Ifa160316e37cf201099ab0d8d89fdd375ee3eb59

ndk/.gitignore

@@ -0,0 +1,6 @@
+samples/*/libs/
+samples/*/obj/
+samples/*/bin/
+samples/*/gen/
+local.properties
+build.xml

ndk/samples/module-exports/README.TXT

@@ -0,0 +1,9 @@
+This sample is used to demonstrate the usage of module exports
+(i.e. LOCAL_EXPORT_CFLAGS and similar other variables).
+
+Here, three modules are defined: foo, bar, zoo
+
+'foo' exports its include directory and a linker flag
+bar simply uses 'foo', as a static library
+zoo uses bar, is a shared library.
+

ndk/samples/module-exports/jni/Android.mk

@@ -0,0 +1,23 @@
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := foo
+LOCAL_SRC_FILES := foo/foo.c
+LOCAL_CFLAGS := -DFOO=2
+LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/foo
+LOCAL_EXPORT_CFLAGS := -DFOO=1
+LOCAL_EXPORT_LDLIBS := -llog
+include $(BUILD_STATIC_LIBRARY)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := bar
+LOCAL_SRC_FILES := bar/bar.c
+LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/bar
+LOCAL_STATIC_LIBRARIES := foo
+include $(BUILD_SHARED_LIBRARY)
+
+include $(CLEAR_VARS)
+LOCAL_MODULE := zoo
+LOCAL_SRC_FILES := zoo/zoo.c
+LOCAL_SHARED_LIBRARIES := bar
+include $(BUILD_SHARED_LIBRARY)

ndk/samples/module-exports/jni/bar/bar.c

@@ -0,0 +1,6 @@
+#include "bar.h"
+
+int  bar(int  x)
+{
+    return foo(x)-1;
+}

ndk/samples/module-exports/jni/bar/bar.h

@@ -0,0 +1,15 @@
+#ifndef BAR_H
+#define BAR_H
+
+/* FOO should be defined to '1' here with the magic of LOCAL_EXPORT_CFLAGS */
+#ifndef FOO
+#error FOO should be defined here !
+#endif
+
+#if FOO != 1
+#error FOO is not correctly defined here !
+#endif
+
+extern int  bar(int  x);
+
+#endif /* BAR_H */

ndk/samples/module-exports/jni/foo/foo.c

@@ -0,0 +1,20 @@
+#include "foo.h"
+#include <android/log.h>
+
+/* FOO should be defined to '2' when building foo.c */
+#ifndef FOO
+#error FOO is not defined here !
+#endif
+
+#if FOO != 2
+#error FOO is incorrectly defined here !
+#endif
+
+#define  LOG_TAG    "libfoo"
+#define  LOGI(...)  __android_log_print(ANDROID_LOG_INFO,LOG_TAG,__VA_ARGS__)
+
+int  foo(int  x)
+{
+    LOGI("foo(%d) called !", x);
+    return x+1;
+}

ndk/samples/module-exports/jni/foo/foo.h

@@ -0,0 +1,6 @@
+#ifndef FOO_H
+#define FOO_H
+
+extern int  foo(int x);
+
+#endif /* FOO_H */

ndk/samples/module-exports/jni/zoo/zoo.c

@@ -0,0 +1,6 @@
+#include "bar.h"
+
+int something(void)
+{
+    return bar(42);
+}