Turn on -Wshadow

Summary:
Only one more try, I promise.

I talked to Jim and he mentioned that if we include our system includes with -isystem rather than with -I, that signals to the compile that those are system includes and thus no warnings are issued. So I turned our glibc includes into system includes and now we no longer get the warning from there, making us shadow-warning-free!

Test Plan: compiles with both clang and gcc

Reviewers: sdong, yhchiang, rven, ljin

Reviewed By: ljin

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28479

.travis.yml

@@ -14,6 +14,6 @@ before_install:
  - sudo dpkg -i libgflags-dev_2.0-1_amd64.deb
 # Lousy hack to disable use and testing of fallocate, which doesn't behave quite
 # as EnvPosixTest::AllocateTest expects within the Travis OpenVZ environment.
-script: OPT=-DTRAVIS make unity && make clean && OPT="-DTRAVIS -Wshadow" make check -j8
+script: OPT=-DTRAVIS make unity && make clean && OPT=-DTRAVIS make check -j8
 notifications:
     email: false

Makefile

@@ -69,7 +69,7 @@ install:
 	@[ ! -e $(SHARED) ] || install -C -m 644 $(SHARED) $(INSTALL_PATH)/lib
 #-------------------------------------------------
 
-WARNING_FLAGS = -Wall -Werror -Wsign-compare
+WARNING_FLAGS = -Wall -Werror -Wsign-compare -Wshadow
 CFLAGS += $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CCFLAGS) $(OPT)
 CXXFLAGS += $(WARNING_FLAGS) -I. -I./include $(PLATFORM_CXXFLAGS) $(OPT) -Woverloaded-virtual
 

build_tools/fbcode_config.sh

@@ -64,10 +64,8 @@ if [ -z "$USE_CLANG" ]; then
   CXX="$GCC_BASE/bin/g++"
   
   CFLAGS="-B$BINUTILS/gold -m64 -mtune=generic"
-  CFLAGS+=" -I $LIBGCC_INCLUDE -I $GLIBC_INCLUDE"
+  CFLAGS+=" -isystem $GLIBC_INCLUDE"
-  CFLAGS+=" $DEPS_INCLUDE"
+  CFLAGS+=" -isystem $LIBGCC_INCLUDE"
-  CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_FALLOCATE_PRESENT"
-  CFLAGS+=" -DSNAPPY -DGFLAGS=google -DZLIB -DBZIP2 -DLZ4 -DNUMA"
 else
   # clang 
   CLANG_BASE="/mnt/gvfs/third-party2/clang/9ab68376f938992c4eb5946ca68f90c3185cffc8/3.4"
@@ -77,7 +75,7 @@ else
 
   KERNEL_HEADERS_INCLUDE="/mnt/gvfs/third-party2/kernel-headers/a683ed7135276731065a9d76d3016c9731f4e2f9/3.2.18_70_fbk11_00129_gc8882d0/gcc-4.8.1-glibc-2.17/da39a3e/include/"
 
-  CFLAGS="-B$BINUTILS  -nostdinc -nostdlib"
+  CFLAGS="-B$BINUTILS/gold -nostdinc -nostdlib"
   CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/4.8.1 "
   CFLAGS+=" -isystem $LIBGCC_BASE/include/c++/4.8.1/x86_64-facebook-linux "
   CFLAGS+=" -isystem $GLIBC_INCLUDE"
@@ -85,13 +83,14 @@ else
   CFLAGS+=" -isystem $CLANG_INCLUDE"
   CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE/linux "
   CFLAGS+=" -isystem $KERNEL_HEADERS_INCLUDE "
-  CFLAGS+=" -Wall -Wno-sign-compare -Wno-unused-variable -Winvalid-pch -Wno-deprecated -Woverloaded-virtual"
+  CXXFLAGS="-nostdinc++"
-  CFLAGS+=" $DEPS_INCLUDE"
-  CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_FALLOCATE_PRESENT"
-  CFLAGS+=" -DSNAPPY -DGFLAGS=google -DZLIB -DBZIP2 -DLZ4 -DNUMA"
-  CXXFLAGS="$CFLAGS -nostdinc++"
 fi
 
+CFLAGS+=" $DEPS_INCLUDE"
+CFLAGS+=" -DROCKSDB_PLATFORM_POSIX -DROCKSDB_FALLOCATE_PRESENT"
+CFLAGS+=" -DSNAPPY -DGFLAGS=google -DZLIB -DBZIP2 -DLZ4 -DNUMA"
+CXXFLAGS+=" $CFLAGS"
+
 EXEC_LDFLAGS=" $SNAPPY_LIBS $ZLIB_LIBS $BZIP_LIBS $LZ4_LIBS $GFLAGS_LIBS $NUMA_LIB"
 EXEC_LDFLAGS+=" -Wl,--dynamic-linker,/usr/local/fbcode/gcc-4.8.1-glibc-2.17/lib/ld.so"
 EXEC_LDFLAGS+=" -Wl,--no-whole-archive $LIBUNWIND"