以下行
# define always_inline __attribute__((always_inline))
被包含（来自另一个包含的文件）并被 gcc 4.9 抱怨：
inc/compiler.h:98:40: error: '__always_inline__' was not declared in this scope
# define always_inline __attribute__((always_inline))
^
奇怪的是，相同的头文件（compiler.h）包含在另一个编译成功的源文件中。有任何想法吗？编辑：我只是确保这always_inline不是预先定义的。供参考：
> g++ -v
Using built-in specs.
COLLECT_GCC=/opt/local/bin/g++-mp-4.9
COLLECT_LTO_WRAPPER=/opt/local/libexec/gcc/x86_64-apple-darwin13/4.9.0/lto-wrapper
Target: x86_64-apple-darwin13
Configured with: /opt/local/var/macports/build/_opt_mports_dports_lang_gcc49/gcc49/work/gcc-4.9-20140406/configure --prefix=/opt/local --build=x86_64-apple-darwin13 --enable-languages=c,c++,objc,obj-c++,fortran,java --libdir=/opt/local/lib/gcc49 --includedir=/opt/local/include/gcc49 --infodir=/opt/local/share/info --mandir=/opt/local/share/man --datarootdir=/opt/local/share/gcc-4.9 --with-local-prefix=/opt/local --with-system-zlib --disable-nls --program-suffix=-mp-4.9 --with-gxx-include-dir=/opt/local/include/gcc49/c++/ --with-gmp=/opt/local --with-mpfr=/opt/local --with-mpc=/opt/local --with-cloog=/opt/local --enable-cloog-backend=isl --disable-cloog-version-check --enable-stage1-checking --disable-multilib --enable-lto --enable-libstdcxx-time --with-as=/opt/local/bin/as --with-ld=/opt/local/bin/ld --with-ar=/opt/local/bin/ar --with-bugurl=https://trac.macports.org/newticket --with-pkgversion='MacPorts gcc49 4.9-20140406_0'
Thread model: posix
gcc version 4.9.0 20140406 (experimental) (MacPorts gcc49 4.9-20140406_0)