https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82787
--- Comment #6 from Ev Drikos <drikosev at gmail dot com> --- 1) the exact version of GCC: $ gcc7 --version gcc7 (GCC) 7.1.1 20170622 Copyright (C) 2017 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 2) the system type: $ uname -a Darwin miniserver.local 17.0.0 Darwin Kernel Version 17.0.0: Thu Aug 24 21:48:19 PDT 2017; root:xnu-4570.1.46~2/RELEASE_X86_64 x86_64 3) the options given when GCC was configured/built $ gcc7 -v Using built-in specs. COLLECT_GCC=gcc7 COLLECT_LTO_WRAPPER=/opt/local/libexec/gcc/x86_64-apple-darwin17/7.1.1/lto-wrapper Target: x86_64-apple-darwin17 Configured with: ../gcc-7-20170622/configure --prefix=/opt/local --program-suffix=7 --build=x86_64-apple-darwin17 --enable-languages=c,c++,fortran --disable-bootstrap --disable-nls --enable-checking=release --with-system-zlib --enable-threads=posix --with-as=/usr/bin/as --with-ld=/usr/bin/ld --with-ar=/usr/bin/ar AR_FOR_TARGET=/usr/bin/ar AS_FOR_TARGET=/usr/bin/as LD_FOR_TARGET=/usr/bin/ld NM_FOR_TARGET=/usr/bin/nm OBJDUMP_FOR_TARGET=/usr/bin/objdump RANLIB_FOR_TARGET=/usr/bin/ranlib STRIP_FOR_TARGET=/usr/bin/strip OTOOL=/usr/bin/otool OTOOL64=/usr/bin/otool LIPO=/usr/bin/lipo LIPO_FOR_TARGET=/usr/bin/lipo CC=/opt/local/bin/gcc CXX=/opt/local/bin/g++ CPP=/opt/local/bin/cpp GCC=/opt/local/bin/gcc CC_FOR_TARGET=/opt/local/bin/gcc CXX_FOR_TARGET=/opt/local/bin/g++ CPP_FOR_TARGET=/opt/local/bin/cpp GCC_FOR_TARGET=/opt/local/bin/gcc CFLAGS='-O2 -g -mmacosx-version-min=10.13 -fstack-protector-strong --param=ssp-buffer-size=4 ' CXXFLAGS='-O2 -g -mmacosx-version-min=10.13 -fstack-protector-strong --param=ssp-buffer-size=4' 'CFLAGS_FOR_TARGET=-O2 -g -mmacosx-version-min=10.13 -fstack-protector-strong --param=ssp-buffer-size=4 ' 'CXXFLAGS_FOR_TARGET=-O2 -g -mmacosx-version-min=10.13 -fstack-protector-strong --param=ssp-buffer-size=4' Thread model: posix gcc version 7.1.1 20170622 (GCC) 4) the complete command line that triggers the bug: $ gcc7 -save-temps syslog.c 5) the compiler output (error messages, warnings, etc.): In file included from /usr/include/syslog.h:23:0, from syslog.c:1: /usr/include/sys/syslog.h:227:84: error: expected ',' or ';' before '__asm' void syslog(int, const char *, ...) __printflike(2, 3) __not_tail_called __DARWIN_ALIAS_STARTING(__MAC_10_13, __IPHONE_NA, __DARWIN_EXTSN(syslog)); ^~~~~ 6) the preprocessed file (*.i*) that triggers the bug, generated by adding -save-temps to the complete compilation command. It's the attachment syslog.i