Reproducible MongoRocks compile with FB toolchain

Summary:
Added a script that will compile MongoRocks with the same flags as RocksDB binary. On FB infra, we can now do:

  cd ~/rocksdb; make static_lib
  cd ~/mongo; ~/rocksdb/build_tools/fb_compile_mongo.sh

No need to upgrade the g++ on the devbox (like Aaron and I did) or maintain a separate script to compile (like Mark did)

fb_compile_mongo.sh gets the settings from fbcode_config.sh, so it also makes it easier to upgrade the environment one day.

Test Plan: Compiled mongod with new script. Also, ldd output looks good: https://phabricator.fb.com/P19891602

Reviewers: AaronFeldman, MarkCallaghan, anthony

Reviewed By: anthony

Subscribers: anthony, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D40659

build_tools/fb_compile_mongo.sh

@@ -0,0 +1,53 @@
+#!/bin/sh
+
+if test -z $ROCKSDB_PATH; then
+  ROCKSDB_PATH=~/rocksdb
+fi
+source $ROCKSDB_PATH/build_tools/fbcode_config.sh
+
+EXTRA_LDFLAGS=""
+
+if test -z $ALLOC; then
+  # default
+  ALLOC=tcmalloc
+elif [[ $ALLOC == "jemalloc" ]]; then
+  ALLOC=system
+  EXTRA_LDFLAGS+=" -Wl,--whole-archive $JEMALLOC_LIB -Wl,--no-whole-archive"
+fi
+
+# we need to force mongo to use static library, not shared
+TEMP_COMPILE_DIR=`mktemp -d /tmp/tmp.mongo_compile.XXX`
+ln -s $SNAPPY_LIBS $TEMP_COMPILE_DIR
+ln -s $LZ4_LIBS $TEMP_COMPILE_DIR
+
+EXTRA_LDFLAGS+=" -L $TEMP_COMPILE_DIR"
+
+set -x
+
+EXTRA_CMD=""
+if ! test -e version.json; then
+  # this is Mongo 3.0
+  EXTRA_CMD="--rocksdb \
+    --variant-dir=linux2/norm
+    --cxx=${CXX} \
+    --cc=${CC} \
+    --use-system-zlib"  # add this line back to normal code path
+                        # when https://jira.mongodb.org/browse/SERVER-19123 is resolved
+fi
+
+scons \
+  LINKFLAGS="$EXTRA_LDFLAGS $EXEC_LDFLAGS $PLATFORM_LDFLAGS" \
+  CCFLAGS="$CXXFLAGS -L $TEMP_COMPILE_DIR" \
+  LIBS="lz4 gcc stdc++" \
+  LIBPATH="$ROCKSDB_PATH" \
+  CPPPATH="$ROCKSDB_PATH/include" \
+  -j32 \
+  --allocator=$ALLOC \
+  --nostrip \
+  --opt=on \
+  --use-system-snappy \
+  --disable-warnings-as-errors \
+  $EXTRA_CMD $*
+
+set +x
+rm -rf $TEMP_COMPILE_DIR

build_tools/fbcode_config.sh

@@ -18,19 +18,6 @@ GLIBC_REV=7397bed99280af5d9543439cdb7d018af7542720
 GLIBC_INCLUDE="/mnt/gvfs/third-party2/glibc/$GLIBC_REV/2.20/gcc-4.9-glibc-2.20/99df8fc/include"
 GLIBC_LIBS=" -L /mnt/gvfs/third-party2/glibc/$GLIBC_REV/2.20/gcc-4.9-glibc-2.20/99df8fc/lib"
 
-# snappy and zlib depend are bundled with MongoDB so we wan't to pick up the bundled headers when
-# building for it and disable block compressors supported by RocksDB but not used by MongoDB.
-
-if [[ -n $ROCKSDB_FOR_MONGO ]]; then
-
-MONGO_SRC="$ROCKSDB_FOR_MONGO/src/third_party"
-SNAPPY_INCLUDE=" -I $MONGO_SRC/snappy-1.1.2"
-CFLAGS+=" -DSNAPPY"
-ZLIB_INCLUDE=" -I $MONGO_SRC/zlib-1.2.8"
-CFLAGS+=" -DZLIB"
-
-else
-
 SNAPPY_INCLUDE=" -I /mnt/gvfs/third-party2/snappy/b0f269b3ca47770121aa159b99e1d8d2ab260e1f/1.0.3/gcc-4.9-glibc-2.20/c32916f/include/"
 
 if test -z $PIC_BUILD; then
@@ -56,7 +43,6 @@ if test -z $PIC_BUILD; then
   LZ4_LIBS=" /mnt/gvfs/third-party2/lz4/79d2943e2dd7208a3e0b06cf95e9f85f05fe9e1b/r124/gcc-4.9-glibc-2.20/4230243/lib/liblz4.a"
   CFLAGS+=" -DLZ4"
 fi
-fi
 
 # location of gflags headers and libraries
 GFLAGS_INCLUDE=" -I /mnt/gvfs/third-party2/gflags/0fa60e2b88de3e469db6c482d6e6dac72f5d65f9/1.6/gcc-4.9-glibc-2.20/4230243/include/"