From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/13630 Path: news.gmane.org!.POSTED!not-for-mail From: Szabolcs Nagy Newsgroups: gmane.linux.lib.musl.general Subject: Re: New to musl and C++ compiling Date: Mon, 21 Jan 2019 13:02:24 +0100 Message-ID: <20190121120224.GS21289@port70.net> References: <20190121115313.GR21289@port70.net> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: ciao.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Trace: ciao.gmane.org 1548072159 40077 195.159.176.228 (21 Jan 2019 12:02:39 GMT) X-Complaints-To: usenet@ciao.gmane.org NNTP-Posting-Date: Mon, 21 Jan 2019 12:02:39 +0000 (UTC) User-Agent: Mutt/1.10.1 (2018-07-13) To: musl@lists.openwall.com, Michele Portolan Original-X-From: musl-return-13646-gllmg-musl=m.gmane.org@lists.openwall.com Mon Jan 21 13:02:33 2019 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by ciao.gmane.org with smtp (Exim 4.84_2) (envelope-from ) id 1glYHd-000AF9-5z for gllmg-musl@m.gmane.org; Mon, 21 Jan 2019 13:02:29 +0100 Original-Received: (qmail 3214 invoked by uid 550); 21 Jan 2019 12:02:36 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 3196 invoked from network); 21 Jan 2019 12:02:36 -0000 Mail-Followup-To: musl@lists.openwall.com, Michele Portolan Content-Disposition: inline In-Reply-To: <20190121115313.GR21289@port70.net> Xref: news.gmane.org gmane.linux.lib.musl.general:13630 Archived-At: * Szabolcs Nagy [2019-01-21 12:53:13 +0100]: > * Michele Portolan [2019-01-21 11:24:1= 2 +0100]: > > Hello, > >=20 > > I just installed MUSL because I have a C++ multithreaded application th= at > > uses threads heavily and I would like to make it independent from an OS= =2E I > > was able to easily install and run MUSL for C targets, but when I try a > > simple C++ Hello world I get an error for the standard libs. > >=20 > > My file is the simplest possible (no multithreading to start with): > >=20 > > =C2=A0#include > >=20 > > =C2=A0int main() { > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 std::cout << "He= llo, World" << std::endl; > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 return 0; > > } > >=20 > > Here is my output for standard and musl-based compilation. > >=20 > > portolan@noumea:~/musl/examples$ g++ -o test_cpp test_cpp.cpp > > portolan@noumea:~/musl/examples$ ./test_cpp > > Hello, World > > portolan@noumea:~/musl/examples$ g++ -o test_cpp test_cpp.cpp -specs > > "/home/portolan/musl/install/lib/musl-gcc.specs" >=20 > for c++ the recommended practice is to use a cross compiler that > is built for musl, instead of a glibc based native compiler with > a specs file or other wrapping mechanism, because c++ headers are > difficult to get right: in this case the specs file disabled all > c++ header paths, you need to add those back manually, see >=20 > g++ -v -E -xc++ - =20 > but there may be still issues > - the header ordering matters as libstdc++ uses include_next and > - some headers are installed based on the libc found at configure > time of gcc, so the abi is slightly different depending on what > libc you built your compiler for, > - e.g. with static linking (which you need if you want a portable > executable) one issue is that libstdc++ has a broken way to > detect multi-threadedness and all locks become nops (unless your > binary has a definition for the 'pthread_cancel' symbol). > if gcc is configured for *-musl* this is fixed. >=20 > in short: use a cross compiler targetting *-linux-musl, there are > prebuilt ones at http://musl.cc/ > (note that you will have to build and install all your application > dependencies into a path where the cross compiler can find them) oh and if you have many dependencies then the simplest way is of course to use a musl based distro (alpine, void, adelie,..) then you can use all the prebuilt packages and the native toolchain with g++ -static and you get a portable executable. (setting up a chroot or docker with whatever distro should not be too much work). > > test_cpp.cpp:1:11: fatal error: iostream: No such file or directory > > =C2=A0 #include > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ^~~~~~~~~~ > > compilation terminated. > >=20 > > I am probably missing something REALLY basic, at least I hope so! > >=20 > > Best regards, > >=20 > >=20 > > Michele