make jni libs Android-agnostic to be able to write robolectric tests

Summary:
- in the next diff D25963204, unit test with Robolectric is added that utilize these jni deps
- make these jni deps Android-aware to be able to run Robolectric tests (basically shimming the necessary deps when `#ifndef __ANDROID__`)

Differential Revision: D25921303

fbshipit-source-id: 16feca072155543c72a5362f746e81d7b8109dd4

deps/build/build.cpp

@@ -3,22 +3,29 @@
 #include <stdlib.h>
 #include <string.h>
 
+#ifdef __ANDROID__
 #include <sys/system_properties.h>
+#endif
 
 namespace facebook {
 namespace build {
 
 int getAndroidSdk() {
+#ifdef __ANDROID__
   static auto android_sdk = ([] {
      char sdk_version_str[PROP_VALUE_MAX];
      __system_property_get("ro.build.version.sdk", sdk_version_str);
      return atoi(sdk_version_str);
   })();
 
   return android_sdk;
+#else
+  return 0;
+#endif
 }
 
 bool isArt() {
+#ifdef __ANDROID__
   int sdk = getAndroidSdk();
   if (sdk >= 21) { // Lollipop (5.0)
     return true;
@@ -33,6 +40,9 @@ bool isArt() {
 
     return running_art;
   }
+#else
+  return false;
+#endif
 }
 
 bool isDalvik() {

deps/cjni/log.h

@@ -15,7 +15,43 @@
  */
 
 #pragma once
+#ifdef ANDROID
 #include <android/log.h>
+#else
+// These declarations are needed for our internal use even on non-Android
+// builds.
+// (they are borrowed from <android/log.h>)
+
+/*
+ * Android log priority values, in ascending priority order.
+ */
+typedef enum android_LogPriority {
+  ANDROID_LOG_UNKNOWN = 0,
+  ANDROID_LOG_DEFAULT, /* only for SetMinPriority() */
+  ANDROID_LOG_VERBOSE,
+  ANDROID_LOG_DEBUG,
+  ANDROID_LOG_INFO,
+  ANDROID_LOG_WARN,
+  ANDROID_LOG_ERROR,
+  ANDROID_LOG_FATAL,
+  ANDROID_LOG_SILENT, /* only for SetMinPriority(); must be last */
+} android_LogPriority;
+
+/*
+ * Send a simple string to the log.
+ */
+int __android_log_write(int prio, const char *tag, const char *text);
+
+/*
+ * Send a formatted string to the log, used like printf(fmt,...)
+ */
+int __android_log_print(int prio, const char *tag, const char *fmt, ...)
+#if defined(__GNUC__)
+    __attribute__((format(printf, 3, 4)))
+#endif
+    ;
+
+#endif
 
 #define LOGV(...) __android_log_print(ANDROID_LOG_VERBOSE, LOG_TAG, __VA_ARGS__)
 #define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__)

deps/linker/elfSharedLibData.cpp

@@ -20,7 +20,6 @@
 
 #include <build/build.h>
 
-#include <sys/system_properties.h>
 #include <stdlib.h>
 #include <dlfcn.h>
 #include <stdexcept>

deps/linker/sharedlibs.cpp

@@ -19,11 +19,13 @@
 
 #include <build/build.h>
 
-#include <sys/system_properties.h>
 #include <stdlib.h>
 #include <dlfcn.h>
 #include <unordered_map>
 #include <libgen.h>
+#ifndef __ANDROID__
+char * basename(char const* path);
+#endif
 
 #define DT_GNU_HASH	0x6ffffef5	/* GNU-style hash table.  */