include-what-you-use-4.0 fails, even on a very simple file: $ cat hello.cpp #include <iostream> int main() { std::clog << "Hello, world!\n"; } $ include-what-you-use hello.cpp In file included from hello.cpp:1: In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/include/g++-v6/iostream:39: In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/include/g++-v6/ostream:38: In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/include/g++-v6/ios:38: In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/include/g++-v6/iosfwd:40: In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/include/g++-v6/bits/postypes.h:40: In file included from /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/include/g++-v6/cwchar:44: /usr/include/wchar.h:39:11: fatal error: 'stdarg.h' file not found # include <stdarg.h> ^~~~~~~~~~ hello.cpp should add these lines: hello.cpp should remove these lines: - #include <iostream> // lines 1-1 The full include-list for hello.cpp: --- The include path seems to be incorrect: $ include-what-you-use -v hello.cpp (…) ignoring nonexistent directory "/usr/local/include" ignoring nonexistent directory "/usr/bin/../../../../lib/clang/4.0.1/include" ignoring nonexistent directory "/include" #include "..." search starts here: #include <...> search starts here: /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/include/g++-v6 /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/include/g++-v6/x86_64-pc-linux-gnu /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/include/g++-v6/backward /usr/include End of search list. (…) # emerge --info Portage 2.3.6 (python 2.7.13-final-0, default/linux/amd64/17.0/desktop/gnome/systemd, gcc-6.3.0, glibc-2.24-r3, 4.13.0-rc1 x86_64) ================================================================= System uname: Linux-4.13.0-rc1-x86_64-Intel-R-_Core-TM-_i7-2720QM_CPU_@_2.20GHz-with-gentoo-2.4.1 KiB Mem: 16367964 total, 2548944 free KiB Swap: 8388604 total, 8388604 free Timestamp of repository gentoo: Sat, 22 Jul 2017 21:43:07 +0000 sh bash 4.4_p12 ld GNU ld (Gentoo 2.28 p1.2) 2.28 app-shells/bash: 4.4_p12::gentoo dev-java/java-config: 2.2.0-r3::gentoo dev-lang/perl: 5.24.2::gentoo dev-lang/python: 2.7.13::gentoo, 3.5.3::gentoo, 3.6.1-r1::gentoo dev-util/cmake: 3.9.0::gentoo dev-util/pkgconfig: 0.29.2::gentoo sys-apps/baselayout: 2.4.1::gentoo sys-apps/openrc: 0.28::gentoo sys-apps/sandbox: 2.10-r4::gentoo sys-devel/autoconf: 2.13::gentoo, 2.69-r3::gentoo sys-devel/automake: 1.11.6-r2::gentoo, 1.13.4-r1::gentoo, 1.15.1::gentoo sys-devel/binutils: 2.28-r2::gentoo sys-devel/gcc: 6.3.0::gentoo sys-devel/gcc-config: 1.8-r1::gentoo sys-devel/libtool: 2.4.6-r4::gentoo sys-devel/make: 4.2.1-r1::gentoo sys-kernel/linux-headers: 4.10::gentoo (virtual/os-headers) sys-libs/glibc: 2.24-r3::gentoo Repositories: gentoo location: /var/cache/repos/gentoo sync-type: rsync sync-uri: rsync://fraktal/gentoo-portage priority: -1000 sync-rsync-extra-opts: -c --filter=clear sync-rsync-vcs-ignore: true embe location: /var/cache/repos/embe sync-type: laymansync sync-uri: git://git.bzium.org/~embe/overlay.git masters: gentoo priority: 50 ACCEPT_KEYWORDS="amd64 ~amd64" ACCEPT_LICENSE="* -@EULA AdobeFlash-11.x Google-TOS google-chrome GIMPS" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=native -O2 -pipe -ggdb" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/share/gnupg/qualified.txt" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/chromium/policies/managed/chrome-gnome-shell.json /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/init.d /etc/opt/chrome/policies/managed/chrome-gnome-shell.json /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c" CXXFLAGS="-march=native -O2 -pipe -ggdb" DISTDIR="/var/cache/distfiles" EMERGE_DEFAULT_OPTS="--with-bdeps y --complete-graph y --quiet-build y" FCFLAGS="-march=native -O2 -pipe -ggdb" FEATURES="assume-digests binpkg-logs buildpkg cgroup clean-logs compressdebug config-protect-if-modified distlocks ebuild-locks fixlafiles ipc-sandbox merge-sync network-sandbox news parallel-fetch preserve-libs protect-owned sandbox sfperms split-log splitdebug strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr" FFLAGS="-march=native -O2 -pipe -ggdb" GENTOO_MIRRORS="http://gentoo.prz.rzeszow.pl http://distfiles.gentoo.org http://www.ibiblio.org/pub/Linux/distributions/gentoo" INSTALL_MASK="/etc/rmt /var/run /etc/xinetd.d /var/lock /var/mail /var/spool/mail /etc/skel /usr/share/man/cat*" LANG="en_US.UTF-8" LC_ALL="en_US.UTF-8" LDFLAGS="-Wl,-O1 -Wl,--as-needed -Wl,--hash-style=gnu -Wl,-z,now" MAKEOPTS="-j8" PKGDIR="/var/cache/packages" PORTAGE_BUNZIP2_COMMAND="lbunzip2" PORTAGE_BZIP2_COMMAND="lbzip2" PORTAGE_COMPRESS="gzip" PORTAGE_COMPRESS_FLAGS="--best" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages --exclude=/.git" PORTAGE_TMPDIR="/tmp" USE="R X a52 aac aacplus acl acpi adns alsa amd64 android archive ass avahi avx bazaar bluetooth bzip2 cairo caps cdb cdda cddb cdr cli clutter colord conntrack crypt cryptsetup cups curl cvs cxx dbus dconf device-mapper dirac djvu dri dts dvb dvd dvdr dvi eds egl elfutils emboss encode evdev evo exif fam fat ffmpeg fftw firefox flac fontconfig fortran fuse gadu gd gdbm gegl geoclue gif gimp git glamor gmp gnome gnome-keyring gnome-online-accounts gnuplot gpg gphoto2 graphicsmagick graphviz gsl gstreamer gtk gtk3 gtkstyle guile http2 iconv icu idn introspection iproute2 ipv6 java jit jpeg jpeg2k lame lapack latex lcms libass libkms libnotify libproxy libsamplerate libsecret live llvm lua lzma lzo mad maildir man matroska mercurial metalink metric mms mmxext mng modemmanager modules mp3 mp4 mpeg mtp multilib musepack nautilus ncurses netlink networkmanager nls nptl obex offensive ogg openal openexr opengl openmp opus osmesa pam pango pcap pch pcre pdf pgf pkcs11 playlist plotutils png policykit postproc postscript ppds pulseaudio python qt3support raw rdp readline rtmp rubberband samba schroedinger sdl seccomp session sftp sip smartcard smi smp snappy speex spell spice sqlite sse3 sse4 sse41 sse4_1 ssl ssse3 startup-notification subversion svg syslog systemd telepathy theora tiff tls tracker truetype udev udisks unicode upnp upnp-av upower urandom usb uuid v4l vaapi vala vdpau vim-syntax vlc vorbis vpx vte webp wifi wxwidgets x264 xattr xcb xinerama xml xmp xmpp xv xvid zeroconf zlib zsh-completion" ABI_X86="32 64" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" APACHE2_MPMS="prefork" CALLIGRA_FEATURES="kexi words flow plan sheets stage tables krita karbon braindump author" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_X86="aes avx mmx mmxext popcnt sse sse2 sse3 sse4_1 sse4_2 ssse3" CURL_SSL="openssl" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock isync itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 timing tsip tripmate tnt ublox ubx" GRUB_PLATFORMS="pc efi-64" INPUT_DEVICES="libinput" KERNEL="linux" L10N="en pl" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="pdfimport nlpsolver" LINGUAS="en en_US pl pl_PL" LLVM_TARGETS="AMDGPU BPF X86" OFFICE_IMPLEMENTATION="libreoffice" POSTGRES_TARGETS="postgres9_5" PYTHON_SINGLE_TARGET="python3_5" PYTHON_TARGETS="python2_7 python3_5 python3_6" QEMU_SOFTMMU_TARGETS="x86_64 i386 arm" QEMU_USER_TARGETS="arm" RUBY_TARGETS="ruby24" USERLAND="GNU" VIDEO_CARDS="radeon r600" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: CC, CPPFLAGS, CTARGET, CXX, PORTAGE_RSYNC_EXTRA_OPTS, USE_PYTHON
Poked a bit at whey that happens. Gentoo's clang can't find one of standard paths for headers. The workaround is to manually pass path to system includes as: - gcc: $ include-what-you-use -I/usr/lib/gcc/x86_64-pc-linux-gnu/7.1.0/include ... - clang: $ include-what-you-use -I/usr/lib/clang/4.0.1/include IWYU uses clang to infer these paths. It's surprising for me why it failed to find clang path. I'll poke a bit more if we can add it to Gentoo's IWYU or clang.
(In reply to Sergei Trofimovich from comment #1) > Poked a bit at whey that happens. Gentoo's clang can't find one of standard > paths for headers. > > The workaround is to manually pass path to system includes as: > > - gcc: $ include-what-you-use > -I/usr/lib/gcc/x86_64-pc-linux-gnu/7.1.0/include ... > - clang: $ include-what-you-use -I/usr/lib/clang/4.0.1/include > > IWYU uses clang to infer these paths. It's surprising for me why > it failed to find clang path. > > I'll poke a bit more if we can add it to Gentoo's IWYU or clang. Aha, found the reason. It's because clang-4.0.1 is installed not into /usr/bin but a few layers deeper: $ cat a.c #include <stddef.h> $ clang -E a.c | grep stddef # 1 "/usr/lib64/llvm/4/bin/../../../../lib/clang/4.0.1/include/stddef.h" 1 3 Note the four ../../../../. When include-what-you-use is installed into /usr/bin it does the same dance against relative binary location causing include search failure: $ strace -f -etrace=stat include-what-you-use a.c ... stat("/usr/include/x86_64-linux-gnu", 0x7fffc44be2c0) = -1 ENOENT (No such file or directory) stat("/usr/include/i686-linux-gnu/64", 0x7fffc44be2c0) = -1 ENOENT (No such file or directory) stat("/usr/include/i486-linux-gnu/64", 0x7fffc44be2c0) = -1 ENOENT (No such file or directory) stat("/usr/local/include", 0x7fffc44c0140) = -1 ENOENT (No such file or directory) stat("/usr/local/include", 0x7fffc44c0060) = -1 ENOENT (No such file or directory) stat("/usr/bin/../../../../lib/clang/4.0.1/include", 0x7fffc44c0140) = -1 ENOENT (No such file or directory) stat("/include", 0x7fffc44c0140) = -1 ENOENT (No such file or directory) stat("/include", 0x7fffc44c0060) = -1 ENOENT (No such file or directory) stat("/usr/include", {st_mode=S_IFDIR|0755, st_size=36130, ...}) = 0 Note the "/usr/bin/../../../../lib/clang/4.0.1/include" Next workaround for me to try is to install IWYU into the same PATH as clang itself. +llvm@ in case it's a known problem with a known workaround.
I've pushed a workaround as: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=c3759ec007c6cda0a7c1100247d455f33a2a1314 Thanks for the report!
