iwyu tries and fails to include stddef.h

[Jeff Abrahamson]

iwyu tries to include stddef.h, fails, and emits a fatal error. But compiling the same file succeeds.

jeff@birdsong:tmp $ cat foo.cc
#include <string>

std::string hello;
jeff@birdsong:tmp $ iwyu -v -std=c++14 foo.cc
clang version 5.0.1-2 (tags/RELEASE_501/final)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/5.5.0
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/6.5.0
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.4.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0
Candidate multilib: .;@m64
Selected multilib: .;@m64
clang invocation:
 "/usr/bin/include-what-you-use" "-cc1" "-triple" "x86_64-pc-linux-gnu" "-fsyntax-only" "-disable-free" "-disable-llvm-verifier" "-discard-value-names" "-main-file-name" "foo.cc" "-mrelocation-model" "static" "-mthread-model" "posix" "-mdisable-fp-elim" "-fmath-errno" "-masm-verbose" "-mconstructor-aliases" "-munwind-tables" "-fuse-init-array" "-target-cpu" "x86-64" "-v" "-dwarf-column-info" "-debugger-tuning=gdb" "-resource-dir" "/usr/lib/clang/5.0.1" "-internal-isystem" "/usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/c++/7.4.0" "-internal-isystem" "/usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/x86_64-linux-gnu/c++/7.4.0" "-internal-isystem" "/usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/x86_64-linux-gnu/c++/7.4.0" "-internal-isystem" "/usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/c++/7.4.0/backward" "-internal-isystem" "/usr/include/clang/5.0.1/include/" "-internal-isystem" "/usr/local/include" "-internal-isystem" "/usr/lib/clang/5.0.1/include" "-internal-externc-isystem" "/usr/include/x86_64-linux-gnu" "-internal-externc-isystem" "/include" "-internal-externc-isystem" "/usr/include" "-std=c++14" "-fdeprecated-macro" "-fdebug-compilation-dir" "/tmp" "-ferror-limit" "19" "-fmessage-length" "105" "-fobjc-runtime=gcc" "-fcxx-exceptions" "-fexceptions" "-fdiagnostics-show-option" "-x" "c++" "foo.cc"

clang -cc1 version 5.0.1 based upon LLVM 5.0.1 default target x86_64-pc-linux-gnu
ignoring nonexistent directory "/usr/include/clang/5.0.1/include/"
ignoring nonexistent directory "/usr/lib/clang/5.0.1/include"
ignoring nonexistent directory "/include"
ignoring duplicate directory "/usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/x86_64-linux-gnu/c++/7.4.0"
#include "..." search starts here:
#include <...> search starts here:
 /usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/c++/7.4.0
 /usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/x86_64-linux-gnu/c++/7.4.0
 /usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/c++/7.4.0/backward
 /usr/local/include
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
In file included from foo.cc:1:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/c++/7.4.0/string:40:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/c++/7.4.0/bits/char_traits.h:40:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/c++/7.4.0/bits/postypes.h:40:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/7.4.0/../../../../include/c++/7.4.0/cwchar:44:
/usr/include/wchar.h:35:10: fatal error: 'stddef.h' file not found
#include <stddef.h>
         ^~~~~~~~~~

(foo.cc has correct #includes/fwd-decls)
2, jeff@birdsong:tmp $

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: iwyu 5.0-1
ProcVersionSignature: Ubuntu 4.15.0-47.50-generic 4.15.18
Uname: Linux 4.15.0-47-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
CurrentDesktop: i3
Date: Wed Jun 12 16:24:07 2019
EcryptfsInUse: Yes
InstallationDate: Installed on 2015-10-23 (1328 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
SourcePackage: iwyu
UpgradeStatus: Upgraded to bionic on 2018-06-14 (363 days ago)

[Jeff Abrahamson (jeff-purple)]

This may be related to the following upstream bugs:

https://github.com/include-what-you-use/include-what-you-use/issues/270
https://github.com/include-what-you-use/include-what-you-use/issues/679

[Martin (martid0311)]

Has there been any issue on this? As a result of this issue, IWYU doesn't work on any projects which include, say, stdlib.h, which makes it completely useless.

While there is an associated upstream bug (https://github.com/include-what-you-use/include-what-you-use/issues/100 being the canonical github issue for it), it can be worked around: https://github.com/include-what-you-use/include-what-you-use#how-to-install. Clearly, the Ubuntu IWYU package doesn't follow those instructions, so this seems like a packaging bug.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Martin (martid0311)]

Actually, this seems to be fixed by installing the `libclang-common-11-dev` package. That makes this basically just a repeat of https://bugs.launchpad.net/ubuntu/+source/iwyu/+bug/1769334.