Without this flag, it's unable to compile libv8 on OS X 10.10 due to
this error message:
ruby ext/libv8/extconf.rb
creating Makefile
HEAD is now at 7ce3fe1... Version 3.16.14
Using existing [svn-remote "svn"]
HEAD is now at f7bc250... Make gyp/win32 compatible with upstream ninja.
Compiling v8 for x64
Using python 2.7.6
Using compiler: /usr/bin/c++ (clang version 5.1)
../src/cached-powers.cc:136:18: error: unused variable 'kCachedPowersLength' [-Werror,-Wunused-const-variable]
static const int kCachedPowersLength = ARRAY_SIZE(kCachedPowers);
^
1 error generated.
make[1]: *** [/Users/sikachu/Projects/libv8/vendor/v8/out/x64.release/obj.target/preparser_lib/src/cached-powers.o] Error 1
make: *** [x64.release] Error 2
GYP_GENERATORS=make \
build/gyp/gyp --generator-output="out" build/all.gyp \
-Ibuild/standalone.gypi --depth=. \
-Dv8_target_arch=x64 \
-S.x64 -Dv8_enable_backtrace=1 -Dv8_can_use_vfp2_instructions=true -Darm_fpu=vfpv2 -Dv8_can_use_vfp3_instructions=true -Darm_fpu=vfpv3
CXX(target) /Users/sikachu/Projects/libv8/vendor/v8/out/x64.release/obj.target/preparser_lib/src/allocation.o
CXX(target) /Users/sikachu/Projects/libv8/vendor/v8/out/x64.release/obj.target/preparser_lib/src/atomicops_internals_x86_gcc.o
CXX(target) /Users/sikachu/Projects/libv8/vendor/v8/out/x64.release/obj.target/preparser_lib/src/bignum.o
CXX(target) /Users/sikachu/Projects/libv8/vendor/v8/out/x64.release/obj.target/preparser_lib/src/bignum-dtoa.o
CXX(target) /Users/sikachu/Projects/libv8/vendor/v8/out/x64.release/obj.target/preparser_lib/src/cached-powers.o
This has been tested against this version of clang and OS X:
$ g++ -v
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn)
Target: x86_64-apple-darwin14.0.0
Thread model: posix
This should fix#123
