diff --git a/Makefile b/Makefile
index c284d4c8b..2858c6ec2 100644
--- a/Makefile
+++ b/Makefile
@@ -16,67 +16,16 @@ OPT ?= -O2 -DNDEBUG       # (A) Production use (optimized mode)
 
 # detect what platform we're building on
 $(shell sh ./build_detect_platform)
-# this file is generated by build_detect_platform to set build flags
+# this file is generated by build_detect_platform to set build flags and sources
 include build_config.mk
 
-# If Snappy is installed, add compilation and linker flags
-# (see http://code.google.com/p/snappy/)
-ifeq ($(SNAPPY), 1)
-SNAPPY_CFLAGS=-DSNAPPY
-SNAPPY_LDFLAGS=-lsnappy
-else
-SNAPPY_CFLAGS=
-SNAPPY_LDFLAGS=
-endif
+CFLAGS += -c -I. -I./include $(PLATFORM_CCFLAGS) $(OPT)
+CXXFLAGS += -c -I. -I./include $(PLATFORM_CXXFLAGS) $(OPT)
 
-# If Google Perf Tools are installed, add compilation and linker flags
-# (see http://code.google.com/p/google-perftools/)
-ifeq ($(GOOGLE_PERFTOOLS), 1)
-GOOGLE_PERFTOOLS_LDFLAGS=-ltcmalloc
-else
-GOOGLE_PERFTOOLS_LDFLAGS=
-endif
+LDFLAGS += $(PLATFORM_LDFLAGS)
 
-CFLAGS = -c -I. -I./include $(PORT_CFLAGS) $(PLATFORM_CFLAGS) $(OPT) $(SNAPPY_CFLAGS)
-
-LDFLAGS += $(PLATFORM_LDFLAGS) $(SNAPPY_LDFLAGS) $(GOOGLE_PERFTOOLS_LDFLAGS)
-
-LIBOBJECTS = \
-	./db/builder.o \
-	./db/c.o \
-	./db/db_impl.o \
-	./db/db_iter.o \
-	./db/filename.o \
-	./db/dbformat.o \
-	./db/log_reader.o \
-	./db/log_writer.o \
-	./db/memtable.o \
-	./db/repair.o \
-	./db/table_cache.o \
-	./db/version_edit.o \
-	./db/version_set.o \
-	./db/write_batch.o \
-	./port/port_posix.o \
-	./table/block.o \
-	./table/block_builder.o \
-	./table/format.o \
-	./table/iterator.o \
-	./table/merger.o \
-	./table/table.o \
-	./table/table_builder.o \
-	./table/two_level_iterator.o \
-	./util/arena.o \
-	./util/cache.o \
-	./util/coding.o \
-	./util/comparator.o \
-	./util/crc32c.o \
-	./util/env.o \
-	./util/env_posix.o \
-	./util/hash.o \
-	./util/histogram.o \
-	./util/logging.o \
-	./util/options.o \
-	./util/status.o
+LIBOBJECTS = $(SOURCES:.cc=.o)
+MEMENVOBJECTS = $(MEMENV_SOURCES:.cc=.o)
 
 TESTUTIL = ./util/testutil.o
 TESTHARNESS = ./util/testharness.o $(TESTUTIL)
@@ -121,13 +70,13 @@ $(LIBRARY): $(LIBOBJECTS)
 	$(AR) -rs $@ $(LIBOBJECTS)
 
 db_bench: db/db_bench.o $(LIBOBJECTS) $(TESTUTIL)
-	$(CXX) $(LDFLAGS) db/db_bench.o $(LIBOBJECTS) $(TESTUTIL) -o $@
+	$(CXX) db/db_bench.o $(LIBOBJECTS) $(TESTUTIL) -o $@  $(LDFLAGS)
 
 db_bench_sqlite3: doc/bench/db_bench_sqlite3.o $(LIBOBJECTS) $(TESTUTIL)
-	$(CXX) -lsqlite3 doc/bench/db_bench_sqlite3.o $(LIBOBJECTS) $(TESTUTIL) -o $@ $(LDFLAGS
+	$(CXX) doc/bench/db_bench_sqlite3.o $(LIBOBJECTS) $(TESTUTIL) -o $@ $(LDFLAGS) -lsqlite3
 
 db_bench_tree_db: doc/bench/db_bench_tree_db.o $(LIBOBJECTS) $(TESTUTIL)
-	$(CXX) $(LDFLAGS) -lkyotocabinet doc/bench/db_bench_tree_db.o $(LIBOBJECTS) $(TESTUTIL) -o $@
+	$(CXX) doc/bench/db_bench_tree_db.o $(LIBOBJECTS) $(TESTUTIL) -o $@ $(LDFLAGS) -lkyotocabinet
 
 arena_test: util/arena_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) util/arena_test.o $(LIBOBJECTS) $(TESTHARNESS) -o $@ $(LDFLAGS)
@@ -177,9 +126,9 @@ version_set_test: db/version_set_test.o $(LIBOBJECTS) $(TESTHARNESS)
 write_batch_test: db/write_batch_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) db/write_batch_test.o $(LIBOBJECTS) $(TESTHARNESS) -o $@ $(LDFLAGS)
 
-$(MEMENVLIBRARY) : helpers/memenv/memenv.o
+$(MEMENVLIBRARY) : $(MEMENVOBJECTS)
 	rm -f $@
-	$(AR) -rs $@ helpers/memenv/memenv.o
+	$(AR) -rs $@ $(MEMENVOBJECTS)
 
 memenv_test : helpers/memenv/memenv_test.o $(MEMENVLIBRARY) $(LIBRARY) $(TESTHARNESS)
 	$(CXX) helpers/memenv/memenv_test.o $(MEMENVLIBRARY) $(LIBRARY) $(TESTHARNESS) -o $@ $(LDFLAGS)
@@ -193,9 +142,9 @@ IOSVERSION=$(shell defaults read /Developer/Platforms/iPhoneOS.platform/version
 
 .cc.o:
 	mkdir -p ios-x86/$(dir $@)
-	$(SIMULATORROOT)/usr/bin/$(CXX) $(CFLAGS) -isysroot $(SIMULATORROOT)/SDKs/iPhoneSimulator$(IOSVERSION).sdk -arch i686 $< -o ios-x86/$@
+	$(SIMULATORROOT)/usr/bin/$(CXX) $(CXXFLAGS) -isysroot $(SIMULATORROOT)/SDKs/iPhoneSimulator$(IOSVERSION).sdk -arch i686 $< -o ios-x86/$@
 	mkdir -p ios-arm/$(dir $@)
-	$(DEVICEROOT)/usr/bin/$(CXX) $(CFLAGS) -isysroot $(DEVICEROOT)/SDKs/iPhoneOS$(IOSVERSION).sdk -arch armv6 -arch armv7 $< -o ios-arm/$@
+	$(DEVICEROOT)/usr/bin/$(CXX) $(CXXFLAGS) -isysroot $(DEVICEROOT)/SDKs/iPhoneOS$(IOSVERSION).sdk -arch armv6 -arch armv7 $< -o ios-arm/$@
 	lipo ios-x86/$@ ios-arm/$@ -create -output $@
 
 .c.o:
@@ -207,7 +156,7 @@ IOSVERSION=$(shell defaults read /Developer/Platforms/iPhoneOS.platform/version
 
 else
 .cc.o:
-	$(CXX) $(CFLAGS) $< -o $@
+	$(CXX) $(CXXFLAGS) $< -o $@
 
 .c.o:
 	$(CC) $(CFLAGS) $< -o $@
diff --git a/build_detect_platform b/build_detect_platform
index 5f9e02187..df85264dc 100644
--- a/build_detect_platform
+++ b/build_detect_platform
@@ -1,93 +1,145 @@
 #!/bin/sh
-
+#
 # Detects OS we're compiling on and generates build_config.mk,
 # which in turn gets read while processing Makefile.
-
+#
 # build_config.mk will set the following variables:
-# - PORT_CFLAGS will either set:
-#               -DLEVELDB_PLATFORM_POSIX if cstatomic is present
-#               -DLEVELDB_PLATFORM_NOATOMIC if it is not
-# - PLATFORM_CFLAGS with compiler flags for the platform
-# - PLATFORM_LDFLAGS with linker flags for the platform
+#   PLATFORM_LDFLAGS            Linker flags
+#   PLATFORM_CCFLAGS            C compiler flags
+#   PLATFORM_CXXFLAGS           C++ compiler flags.  Will contain:
+#       -DLEVELDB_PLATFORM_POSIX if cstdatomic is present
+#       -DLEVELDB_PLATFORM_NOATOMIC if it is not
+
+SCRIPT_DIR=`dirname $0`
 
 # Delete existing build_config.mk
 rm -f build_config.mk
+touch build_config.mk
 
 if test -z "$CXX"; then
     CXX=g++
 fi
 
 # Detect OS
-case `uname -s` in
+if test -z "$TARGET_OS"; then
+    TARGET_OS=`uname -s`
+fi
+
+COMMON_FLAGS=
+PLATFORM_CCFLAGS=
+PLATFORM_CXXFLAGS=
+PLATFORM_LDFLAGS=
+
+# On GCC, we pick libc's memcmp over GCC's memcmp via -fno-builtin-memcmp
+case "$TARGET_OS" in
     Darwin)
         PLATFORM=OS_MACOSX
-        echo "PLATFORM_CFLAGS=-DOS_MACOSX" >> build_config.mk
-        echo "PLATFORM_LDFLAGS="  >> build_config.mk
+        COMMON_FLAGS="-fno-builtin-memcmp -DOS_MACOSX"
+        PORT_FILE=port/port_posix.cc
         ;;
     Linux)
         PLATFORM=OS_LINUX
-        echo "PLATFORM_CFLAGS=-pthread -DOS_LINUX" >> build_config.mk
-        echo "PLATFORM_LDFLAGS=-pthread"  >> build_config.mk
+        COMMON_FLAGS="-fno-builtin-memcmp -pthread -DOS_LINUX"
+        PLATFORM_LDFLAGS="-pthread"
+        PORT_FILE=port/port_posix.cc
         ;;
     SunOS)
         PLATFORM=OS_SOLARIS
-        echo "PLATFORM_CFLAGS=-D_REENTRANT -DOS_SOLARIS"  >> build_config.mk
-        echo "PLATFORM_LDFLAGS=-lpthread -lrt" >> build_config.mk
+        COMMON_FLAGS="-fno-builtin-memcmp -D_REENTRANT -DOS_SOLARIS"
+        PLATFORM_LDFLAGS="-lpthread -lrt"
+        PORT_FILE=port/port_posix.cc
         ;;
     FreeBSD)
         PLATFORM=OS_FREEBSD
-        echo "PLATFORM_CFLAGS=-D_REENTRANT -DOS_FREEBSD"  >> build_config.mk
-        echo "PLATFORM_LDFLAGS=-lpthread" >> build_config.mk
+        COMMON_FLAGS="-fno-builtin-memcmp -D_REENTRANT -DOS_FREEBSD"
+        PLATFORM_LDFLAGS="-lpthread"
+        PORT_FILE=port/port_posix.cc
         ;;
     NetBSD)
         PLATFORM=OS_NETBSD
-        echo "PLATFORM_CFLAGS=-D_REENTRANT -DOS_NETBSD"  >> build_config.mk
-        echo "PLATFORM_LDFLAGS=-lpthread -lgcc_s" >> build_config.mk
+        COMMON_FLAGS="-fno-builtin-memcmp -D_REENTRANT -DOS_NETBSD"
+        PLATFORM_LDFLAGS="-lpthread -lgcc_s"
+        PORT_FILE=port/port_posix.cc
         ;;
     OpenBSD)
         PLATFORM=OS_OPENBSD
-        echo "PLATFORM_CFLAGS=-D_REENTRANT -DOS_OPENBSD"  >> build_config.mk
-        echo "PLATFORM_LDFLAGS=-pthread" >> build_config.mk
+        COMMON_FLAGS="-fno-builtin-memcmp -D_REENTRANT -DOS_OPENBSD"
+        PLATFORM_LDFLAGS="-pthread"
+        PORT_FILE=port/port_posix.cc
         ;;
     DragonFly)
         PLATFORM=OS_DRAGONFLYBSD
-        echo "PLATFORM_CFLAGS=-D_REENTRANT -DOS_DRAGONFLYBSD"  >> build_config.mk
-        echo "PLATFORM_LDFLAGS=-lpthread" >> build_config.mk
+        COMMON_FLAGS="-fno-builtin-memcmp -D_REENTRANT -DOS_DRAGONFLYBSD"
+        PLATFORM_LDFLAGS="-lpthread"
+        PORT_FILE=port/port_posix.cc
+        ;;
+    OS_ANDROID_CROSSCOMPILE)
+        PLATFORM="$TARGET_OS"
+        COMMON_FLAGS=""
+        PLATFORM_LDFLAGS=""
+        PORT_FILE=port/port_android.cc
         ;;
     *)
         echo "Unknown platform!"
         exit 1
 esac
 
+# We want to make a list of all cc files within util, db, table, and helpers
+# except for the test and benchmark files. By default, find will output a list
+# of all files matching either rule, so we need to append -print to make the
+# prune take effect.
+DIRS="$SCRIPT_DIR/util $SCRIPT_DIR/db $SCRIPT_DIR/table"
+set -f # temporarily disable globbing so that our patterns aren't expanded
+PRUNE_TEST="-name *test*.cc -prune"
+PRUNE_BENCH="-name *_bench.cc -prune"
+PORTABLE_FILES=`find $DIRS $PRUNE_TEST -o $PRUNE_BENCH -o -name '*.cc' -print | sort | tr "\n" " "`
+set +f # re-enable globbing
+
+# The sources consist of the portable files, plus the platform-specific port
+# file.
+echo "SOURCES=$PORTABLE_FILES $PORT_FILE" >> build_config.mk
+echo "MEMENV_SOURCES=helpers/memenv/memenv.cc" >> build_config.mk
+
+if [ "$PLATFORM" = "OS_ANDROID_CROSSCOMPILE" ]; then
+    # Cross-compiling; do not try any compilation tests.
+    true
+else
+    # If -std=c++0x works, use <cstdatomic>.  Otherwise use port_posix.h.
+    $CXX $CFLAGS -std=c++0x -x c++ - -o /dev/null 2>/dev/null  <<EOF
+      #include <cstdatomic>
+      int main() {}
+EOF
+    if [ "$?" = 0 ]; then
+        COMMON_FLAGS="$COMMON_FLAGS -DLEVELDB_PLATFORM_POSIX -DLEVELDB_CSTDATOMIC_PRESENT"
+        PLATFORM_CXXFLAGS="-std=c++0x"
+    else
+        COMMON_FLAGS="$COMMON_FLAGS -DLEVELDB_PLATFORM_POSIX"
+    fi
+
+    # Test whether Snappy library is installed
+    # http://code.google.com/p/snappy/
+    $CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
+      #include <snappy.h>
+      int main() {}
+EOF
+    if [ "$?" = 0 ]; then
+        COMMON_FLAGS="$COMMON_FLAGS -DSNAPPY"
+        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lsnappy"
+    fi
+
+    # Test whether tcmalloc is available
+    $CXX $CFLAGS -x c++ - -o /dev/null -ltcmalloc 2>/dev/null  <<EOF
+      int main() {}
+EOF
+    if [ "$?" = 0 ]; then
+        PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -ltcmalloc"
+    fi
+fi
+
+PLATFORM_CCFLAGS="$PLATFORM_CCFLAGS $COMMON_FLAGS"
+PLATFORM_CXXFLAGS="$PLATFORM_CXXFLAGS $COMMON_FLAGS"
+
 echo "PLATFORM=$PLATFORM" >> build_config.mk
-
-# On GCC, use libc's memcmp, not GCC's memcmp
-PORT_CFLAGS="-fno-builtin-memcmp"
-
-# Detect C++0x -- this determines whether we'll use port_noatomic.h
-# or port_posix.h by:
-# 1. Rrying to compile with -std=c++0x and including <cstdatomic>.
-# 2. If $CXX returns error code, we know to use port_posix.h
-$CXX $CFLAGS -std=c++0x -x c++ - -o /dev/null 2>/dev/null  <<EOF
-  #include <cstdatomic>
-  int main() {}
-EOF
-if [ "$?" = 0 ]; then
-    PORT_CFLAGS="$PORT_CFLAGS -DLEVELDB_PLATFORM_POSIX -DLEVELDB_CSTDATOMIC_PRESENT -std=c++0x"
-else
-    PORT_CFLAGS="$PORT_CFLAGS -DLEVELDB_PLATFORM_POSIX"
-fi
-
-# Test whether Snappy library is installed
-# http://code.google.com/p/snappy/
-$CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
-  #include <snappy.h>
-  int main() {}
-EOF
-if [ "$?" = 0 ]; then
-    echo "SNAPPY=1" >> build_config.mk
-else
-    echo "SNAPPY=0" >> build_config.mk
-fi
-
-echo "PORT_CFLAGS=$PORT_CFLAGS" >> build_config.mk
+echo "PLATFORM_LDFLAGS=$PLATFORM_LDFLAGS" >> build_config.mk
+echo "PLATFORM_CCFLAGS=$PLATFORM_CCFLAGS" >> build_config.mk
+echo "PLATFORM_CXXFLAGS=$PLATFORM_CXXFLAGS" >> build_config.mk
diff --git a/port/port_android.h b/port/port_android.h
index 64cdcbf0f..92f009028 100644
--- a/port/port_android.h
+++ b/port/port_android.h
@@ -10,7 +10,7 @@
 #include <endian.h>
 #include <pthread.h>
 #include <stdint.h>
-#include <cstdatomic>
+#include <unistd.h>
 #include <string>
 #include <cctype>