Add ROCKSDB_DISABLE_* environment variables

Summary:
Should fix #3036.
Closes https://github.com/facebook/rocksdb/pull/3042

Differential Revision: D6452921

Pulled By: sagar0

fbshipit-source-id: eaf11e43fee1f8747006530cfc0c7a358f1c2f0f

build_tools/build_detect_platform

@@ -210,6 +210,7 @@ EOF
         fi
     fi
 
+    if ! test $ROCKSDB_DISABLE_SNAPPY; then
         # Test whether Snappy library is installed
         # http://code.google.com/p/snappy/
         $CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
@@ -221,7 +222,9 @@ EOF
             PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lsnappy"
             JAVA_LDFLAGS="$JAVA_LDFLAGS -lsnappy"
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_GFLAGS; then
         # Test whether gflags library is installed
         # http://gflags.github.io/gflags/
         # check if the namespace is gflags
@@ -232,8 +235,21 @@ EOF
         if [ "$?" = 0 ]; then
             COMMON_FLAGS="$COMMON_FLAGS -DGFLAGS=1"
             PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lgflags"
+        else
+          # check if namespace is google
+          $CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null << EOF
+            #include <gflags/gflags.h>
+            using namespace google;
+            int main() {}
+EOF
+          if [ "$?" = 0 ]; then
+              COMMON_FLAGS="$COMMON_FLAGS -DGFLAGS=google"
+              PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lgflags"
+          fi
+        fi
     fi
 
+    if ! test $ROCKSDB_DISABLE_ZLIB; then
         # Test whether zlib library is installed
         $CXX $CFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
           #include <zlib.h>
@@ -244,7 +260,9 @@ EOF
             PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lz"
             JAVA_LDFLAGS="$JAVA_LDFLAGS -lz"
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_BZIP; then
         # Test whether bzip library is installed
         $CXX $CFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
           #include <bzlib.h>
@@ -255,7 +273,9 @@ EOF
             PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lbz2"
             JAVA_LDFLAGS="$JAVA_LDFLAGS -lbz2"
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_LZ4; then
         # Test whether lz4 library is installed
         $CXX $CFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
           #include <lz4.h>
@@ -267,7 +287,9 @@ EOF
             PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -llz4"
             JAVA_LDFLAGS="$JAVA_LDFLAGS -llz4"
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_ZSTD; then
         # Test whether zstd library is installed
         $CXX $CFLAGS $COMMON_FLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
           #include <zstd.h>
@@ -278,7 +300,9 @@ EOF
             PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lzstd"
             JAVA_LDFLAGS="$JAVA_LDFLAGS -lzstd"
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_NUMA; then
         # Test whether numa is available
         $CXX $CFLAGS -x c++ - -o /dev/null -lnuma 2>/dev/null  <<EOF
           #include <numa.h>
@@ -290,7 +314,9 @@ EOF
             PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -lnuma"
             JAVA_LDFLAGS="$JAVA_LDFLAGS -lnuma"
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_TBB; then
         # Test whether tbb is available
         $CXX $CFLAGS $LDFLAGS -x c++ - -o /dev/null -ltbb 2>/dev/null  <<EOF
           #include <tbb/tbb.h>
@@ -301,7 +327,9 @@ EOF
             PLATFORM_LDFLAGS="$PLATFORM_LDFLAGS -ltbb"
             JAVA_LDFLAGS="$JAVA_LDFLAGS -ltbb"
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_JEMALLOC; then
         # Test whether jemalloc is available
         if echo 'int main() {}' | $CXX $CFLAGS -x c++ - -o /dev/null -ljemalloc \
           2>/dev/null; then
@@ -310,7 +338,9 @@ EOF
             # JEMALLOC can be enabled either using the flag (like here) or by
             # providing direct link to the jemalloc library
             WITH_JEMALLOC_FLAG=1
-    else
+        fi
+    fi
+    if ! test $JEMALLOC && ! test $ROCKSDB_DISABLE_TCMALLOC; then
         # jemalloc is not available. Let's try tcmalloc
         if echo 'int main() {}' | $CXX $CFLAGS -x c++ - -o /dev/null \
           -ltcmalloc 2>/dev/null; then
@@ -319,6 +349,7 @@ EOF
         fi
     fi
 
+    if ! test $ROCKSDB_DISABLE_MALLOC_USABLE_SIZE; then
         # Test whether malloc_usable_size is available
         $CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
           #include <malloc.h>
@@ -330,7 +361,9 @@ EOF
         if [ "$?" = 0 ]; then
             COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_MALLOC_USABLE_SIZE"
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_PTHREAD_MUTEX_ADAPTIVE_NP; then
         # Test whether PTHREAD_MUTEX_ADAPTIVE_NP mutex type is available
         $CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
           #include <pthread.h>
@@ -342,7 +375,9 @@ EOF
         if [ "$?" = 0 ]; then
             COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_PTHREAD_ADAPTIVE_MUTEX"
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_BACKTRACE; then
         # Test whether backtrace is available
         $CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
           #include <execinfo.h>>
@@ -369,7 +404,9 @@ EOF
                 JAVA_LDFLAGS="$JAVA_LDFLAGS -lexecinfo"
             fi
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_PG; then
         # Test if -pg is supported
         $CXX $CFLAGS -pg -x c++ - -o /dev/null 2>/dev/null  <<EOF
           int main() {
@@ -379,7 +416,9 @@ EOF
         if [ "$?" = 0 ]; then
             PROFILING_FLAGS=-pg
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_SYNC_FILE_RANGE; then
         # Test whether sync_file_range is supported for compatibility with an old glibc
         $CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
           #include <fcntl.h>
@@ -391,7 +430,9 @@ EOF
         if [ "$?" = 0 ]; then
             COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_RANGESYNC_PRESENT"
         fi
+    fi
 
+    if ! test $ROCKSDB_DISABLE_SCHED_GETCPU; then
         # Test whether sched_getcpu is supported
         $CXX $CFLAGS -x c++ - -o /dev/null 2>/dev/null  <<EOF
           #include <sched.h>
@@ -403,6 +444,7 @@ EOF
             COMMON_FLAGS="$COMMON_FLAGS -DROCKSDB_SCHED_GETCPU_PRESENT"
         fi
     fi
+fi
 
 # TODO(tec): Fix -Wshorten-64-to-32 errors on FreeBSD and enable the warning.
 # -Wshorten-64-to-32 breaks compilation on FreeBSD i386