From: Brian Inglis <Brian.Inglis@Shaw.ca>
To: cygwin@cygwin.com
Cc: ggl329 <ggl329@gmail.com>
Subject: Re: iostream doesn't work (clang++)
Date: Wed, 5 Jul 2023 17:08:34 -0600 [thread overview]
Message-ID: <dbce604a-f7ac-e30f-19db-609a71d2757e@Shaw.ca> (raw)
In-Reply-To: <3c02f650-248e-9e03-94a8-d508c857474e@gmail.com>
On 2023-07-05 09:54, ggl329 via Cygwin wrote:
> Hi Mark,
>
> On 2023/07/05 12:06, Mark Geisert via Cygwin wrote:
>> My previous reply addressed the specific error reported by your testcase.
>> But I am unable to make progress on the root cause because I can't reproduce
>> your report.
>
> Hm, it seems to be difficult to track down the root cause...
>
>> On my system I try the compilation and see:
>> ~ clang++ sample.cc
>> sample.cc:1:10: fatal error: 'iostream' file not found
>> #include <iostream>
>> ^~~~~~~~~~
>> 1 error generated.
>
> I tried with clang++ --verbose, and the log showed search paths for #include.
> iostream is at /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/iostream.
> Can you find it? It comes from gcc-g++.
> Or the search path includes /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++?
Package clang pulls in headers and libraries from libc++-devel libclang8
libunwind-devel gcc-g++ libstdc++6 gcc-core cygwin-devel so the primary include
paths should be from:
libc++-devel /usr/include/c++/v1/ for most language and library definitions and
libraries,
libclang8 /usr/lib/clang/8.0.1/include/ for clang intrinsics and builtins,
libunwind-devel /usr/include/ for exception handling definitions and libraries,
gcc-g++ /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/{x86_64-pc-cygwin/,} and
libstdc++6 for C++ system dependent and low level definitions and libraries,
gcc-core /usr/lib/gcc/x86_64-pc-cygwin/11/include/ for system dependent and low
level intrinsics and interfaces, and
cygwin-devel /usr/include/{*/,} for system dependent and low level definitions
and libraries.
Everything clang should be prioritized over anything gcc to prevent such issues,
so cygcheck -c clang llvm libc++-devel libclang8 libunwind-devel gcc-g++
libstdc++6 gcc-core cygwin-devel to ensure eveything has been installed properly.
Unfortunately clang{,++,-cpp} -print-search-dirs does *NOT* show include paths,
but -v and -### complain about nonexistent /usr/include/c++/11 where
/usr/include/c++/v1 exists!
It appears the search list ignores the directories populated in libc++-devel:
... -resource-dir /usr/lib/clang/8.0.1
-internal-isystem /usr/x86_64-pc-cygwin/include/c++
-internal-isystem /usr/x86_64-pc-cygwin/include/c++/x86_64-pc-cygwin
-internal-isystem /usr/x86_64-pc-cygwin/include/c++/backward
-internal-isystem /usr/x86_64-pc-cygwin/include/c++/11
-internal-isystem /usr/x86_64-pc-cygwin/include/c++/11/x86_64-pc-cygwin
-internal-isystem /usr/x86_64-pc-cygwin/include/c++/11/backward
-internal-isystem /usr/include/c++/11
-internal-isystem /usr/include/c++/11/x86_64-pc-cygwin
-internal-isystem /usr/include/c++/11/backward
-internal-isystem /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++
-internal-isystem /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/x86_64-pc-cygwin
-internal-isystem /usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/backward
-internal-isystem /usr/lib/clang/8.0.1/include
-internal-isystem /usr/local/include
-internal-isystem /usr/lib/clang/8.0.1/include
-internal-isystem /usr/x86_64-pc-cygwin/include
-internal-isystem /usr/include
-internal-isystem /usr/include/w32api ...
ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include/c++"
ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include/c++/x86_64-pc-cygwin"
ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include/c++/backward"
ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include/c++/11"
ignoring nonexistent directory
"/usr/x86_64-pc-cygwin/include/c++/11/x86_64-pc-cygwin"
ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include/c++/11/backward"
ignoring nonexistent directory "/usr/include/c++/11"
ignoring nonexistent directory "/usr/include/c++/11/x86_64-pc-cygwin"
ignoring nonexistent directory "/usr/include/c++/11/backward"
ignoring nonexistent directory "/usr/x86_64-pc-cygwin/include"
ignoring duplicate directory "/usr/lib/clang/8.0.1/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/lib/gcc/x86_64-pc-cygwin/11/include/c++
/usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/x86_64-pc-cygwin
/usr/lib/gcc/x86_64-pc-cygwin/11/include/c++/backward
/usr/lib/clang/8.0.1/include
/usr/local/include
/usr/include
/usr/include/w32api
End of search list.
You may want to try to override the built in includes from -internal-isystem
with those mentioned above but not built in.
I have no idea why both compilers would include w32api headers as if they were
building Mingw cross compilers!
--
Take care. Thanks, Brian Inglis Calgary, Alberta, Canada
La perfection est atteinte Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut
-- Antoine de Saint-Exupéry
next prev parent reply other threads:[~2023-07-05 23:08 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-04 16:48 ggl329
2023-07-04 18:51 ` Mark Geisert
2023-07-05 3:06 ` Mark Geisert
2023-07-05 15:54 ` ggl329
2023-07-05 23:08 ` Brian Inglis [this message]
2023-07-07 8:01 ` Mark Geisert
2023-07-07 15:48 ` Jon Turney
2023-07-07 18:18 ` gs-cygwin.com
2023-07-08 9:12 ` Jon Turney
2023-07-13 5:52 ` Mark Geisert
2023-07-13 16:11 ` ggl329
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