[Bug preprocessor/63662] New: __has_include defined but not implemented

["andre.mccurdy at linaro dot org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63662

            Bug ID: 63662
           Summary: __has_include defined but not implemented
           Product: gcc
           Version: 4.9.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: preprocessor
          Assignee: unassigned at gcc dot gnu.org
          Reporter: andre.mccurdy at linaro dot org

Issue seen with Linaro GCC 4.9-2014.10, but believed to also be present in
upstream gcc 4.9.x

$ i586-rdk-linux-gcc -v
Using built-in specs.
COLLECT_GCC=i586-rdk-linux-gcc
COLLECT_LTO_WRAPPER=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr/libexec/i586-rdk-linux/gcc/i586-rdk-linux/4.9.2/lto-wrapper
Target: i586-rdk-linux
Configured with:
/home/andre/rdk/rdk-master/build-qemux86/tmp/work-shared/gcc-linaro-4.9-r2014.10/gcc-linaro-4.9-2014.10/configure
--build=x86_64-linux --host=x86_64-linux --target=i586-rdk-linux
--prefix=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr
--exec_prefix=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr
--bindir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr/bin/i586-rdk-linux
--sbindir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr/bin/i586-rdk-linux
--libexecdir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr/libexec/i586-rdk-linux
--datadir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr/share
--sysconfdir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/etc
--sharedstatedir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/com
--localstatedir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/var
--libdir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr/lib/i586-rdk-linux
--includedir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr/include
--oldincludedir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr/include
--infodir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr/share/info
--mandir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr/share/man
--disable-silent-rules --disable-dependency-tracking
--with-libtool-sysroot=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux
--enable-clocale=generic --with-gnu-ld --enable-shared --enable-languages=c,c++
--enable-threads=posix --disable-multilib --enable-c99 --enable-long-long
--enable-symvers=gnu --enable-libstdcxx-pch --program-prefix=i586-rdk-linux-
--without-local-prefix --enable-target-optspace --enable-lto --enable-libssp
--disable-bootstrap --disable-libmudflap --with-system-zlib
--with-linker-hash-style=gnu --enable-linker-build-id --with-ppl=no
--with-cloog=no --enable-checking=release --enable-cheaders=c_global
--with-gxx-include-dir=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/qemux86/usr/include/c++/4.9.2
--with-sysroot=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/qemux86
--with-build-sysroot=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/qemux86
--enable-targets=all --enable-poison-system-directories
--with-mpfr=/home/andre/rdk/rdk-master/build-qemux86/tmp/sysroots/x86_64-linux/usr
--with-system-zlib --disable-nls --enable-__cxa_atexit
Thread model: posix
gcc version 4.9.2 20141013 (prerelease) (Linaro GCC 4.9-2014.10) 


Issue originally seen when building Qt 5.4 alpha1, which includes references to
__has_include such as:

https://qt.gitorious.org/qt/qtbase/source/8e512fbe0b0f99d80d0cf60cd6187a9a9a5a3eb9:src/corelib/global/qlogging.cpp#L77

Minimal testcase:

$ cat tst.c
#ifdef __has_include
#  if __has_include(<stdio.h>)
#    include <stdio.h>
#  endif
#endif

$ i586-rdk-linux-gcc -c tst.c
tst.c:2:7: error: missing binary operator before token "("
 #  if __has_include(<stdio.h>)
       ^

Related gcc-4_9-branch check-in ( SVN r215998 ):

https://gcc.gnu.org/viewcvs/gcc?limit_changes=0&view=revision&revision=215998