Message ID | 20220413142359.577396-1-jwakely@redhat.com |
---|---|
State | New |
Headers | show |
Series | libstdc++: Use LTLIBICONV when linking libstdc++.so [PR93602] | expand |
Pushed to trunk now. On Wed, 13 Apr 2022 at 15:24, Jonathan Wakely via Libstdc++ <libstdc++@gcc.gnu.org> wrote: > > Tested x86_64-linux, without libiconv installed, with libiconv installed, > with libiconv installed but using an in-tree libiconv, with libiconv.a > installed and using --with-libiconv-type=static, and with libiconv.so > installed and using --without-libiconv-prefix (which still fails). > > I'm not entirely happy about the fact that libtool's LTLIBICONV adds an > rpath to libstdc++.so, but that can be avoided (as documented by this > patch) and I don't really see a better solution. Another option would be > to use -l:libiconv.a if configure defines LTLIBICONV to non-empty and > the linker supports it, which would *force* the use of a static lib. But > that seems unnecessarily hostile; not all users will dislike the rpath > solution. The proposed patch makes it Just Work™ for users who (for > whatever reason) have installed libiconv, while also allowing them to do > something more sensible if they care enough to do so. > > Thoughts? > > -- >8 -- > > This fixes missing libiconv symbols when libstdc++ is built on a system > that has libiconv installed. If the libiconv headers are found then > libstdc++ depends on libiconv_open etc instead of libc's iconv_open. But > without this fix libstdc++ is not linked to the libiconv library that > provides the definitions of those symbols. > > As discussed in PR 93602 this changed means that libstdc++.so.6 might > have an rpath pointing to the location of the libiconv.so library. If > that is not desired, then GCC must be configured to link to a static > libiconv.a instead, using either --with-libiconv-type=static or an > in-tree build of libiconv. > > libstdc++-v3/ChangeLog: > > PR libstdc++/93602 > * doc/xml/manual/prerequisites.xml: Document libiconv > workarounds. > * doc/html/manual/setup.html: Regenerate. > * src/Makefile.am (CXXLINK): Add $(LTLIBICONV). > * src/Makefile.in: Regenerate. > --- > diff --git a/libstdc++-v3/doc/xml/manual/prerequisites.xml b/libstdc++-v3/doc/xml/manual/prerequisites.xml > index 22e90a7e79d..8799487c821 100644 > --- a/libstdc++-v3/doc/xml/manual/prerequisites.xml > +++ b/libstdc++-v3/doc/xml/manual/prerequisites.xml > @@ -48,6 +48,56 @@ > <varlistentry> > <term>linux</term> > > + <listitem> > + <para> > + The 'gnu' locale model makes use of <function>iconv</function> > + for character set conversions. The relevant functions are provided > + by Glibc and so are always available, however they can also be > + provided by the separate GNU libiconv library. If GNU libiconv is > + found when GCC is built (e.g., because its headers are installed > + in <filename class="directory">/usr/local/include</filename>) > + then the <filename>libstdc++.so.6</filename> library will have a > + run-time dependency on <filename>libiconv.so.2</filename>. > + If you do not want that run-time dependency then you should do > + one of the following: > + </para> > + <itemizedlist> > + <listitem> > + <para> > + Uninstall the libiconv headers before building GCC. > + Glibc already provides <function>iconv</function> so you should > + not need libiconv anyway. > + </para> > + </listitem> > + <listitem> > + <para> > + <link linkend="https://www.gnu.org/software/libiconv/#downloading"> > + Download</link> the libiconv sources and extract them into the > + top level of the GCC source tree, e.g., > + </para> > +<programlisting> > +wget https://ftp.gnu.org/pub/gnu/libiconv/libiconv-1.16.tar.gz > +tar xf libiconv-1.16.tar.gz > +ln -s libiconv-1.16 libiconv > +</programlisting> > + <para> > + This will build libiconv as part of building GCC and link to > + it statically, so there is no <filename>libiconv.so.2</filename> > + dependency. > + </para> > + </listitem> > + <listitem> > + <para> > + Configure GCC with <option>--with-libiconv-type=static</option>. > + This requires the static <filename>libiconv.a</filename> library, > + which is not installed by default. You might need to reinstall > + libiconv using the <option>--enable-static</option> configure > + option to get the static library. > + </para> > + </listitem> > + </itemizedlist> > + </listitem> > + > <listitem> > <para> > If GCC 3.1.0 or later on is being used on GNU/Linux, an attempt > diff --git a/libstdc++-v3/src/Makefile.am b/libstdc++-v3/src/Makefile.am > index 18f57632c3d..9c3f4aca655 100644 > --- a/libstdc++-v3/src/Makefile.am > +++ b/libstdc++-v3/src/Makefile.am > @@ -278,7 +278,9 @@ CXXLINK = \ > $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \ > --mode=link $(CXX) \ > $(VTV_CXXLINKFLAGS) \ > - $(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@ > + $(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) \ > + $(LTLDFLAGS) $(LTLIBICONV) \ > + -o $@ > > # Symbol versioning for shared libraries. > if ENABLE_SYMVERS >
Hi, Will this be in GCC12? -- Yubin On Wed, Apr 20, 2022 at 8:58 PM Jonathan Wakely via Libstdc++ <libstdc++@gcc.gnu.org> wrote: > > Pushed to trunk now. > > On Wed, 13 Apr 2022 at 15:24, Jonathan Wakely via Libstdc++ > <libstdc++@gcc.gnu.org> wrote: > > > > Tested x86_64-linux, without libiconv installed, with libiconv installed, > > with libiconv installed but using an in-tree libiconv, with libiconv.a > > installed and using --with-libiconv-type=static, and with libiconv.so > > installed and using --without-libiconv-prefix (which still fails). > > > > I'm not entirely happy about the fact that libtool's LTLIBICONV adds an > > rpath to libstdc++.so, but that can be avoided (as documented by this > > patch) and I don't really see a better solution. Another option would be > > to use -l:libiconv.a if configure defines LTLIBICONV to non-empty and > > the linker supports it, which would *force* the use of a static lib. But > > that seems unnecessarily hostile; not all users will dislike the rpath > > solution. The proposed patch makes it Just Work™ for users who (for > > whatever reason) have installed libiconv, while also allowing them to do > > something more sensible if they care enough to do so. > > > > Thoughts? > > > > -- >8 -- > > > > This fixes missing libiconv symbols when libstdc++ is built on a system > > that has libiconv installed. If the libiconv headers are found then > > libstdc++ depends on libiconv_open etc instead of libc's iconv_open. But > > without this fix libstdc++ is not linked to the libiconv library that > > provides the definitions of those symbols. > > > > As discussed in PR 93602 this changed means that libstdc++.so.6 might > > have an rpath pointing to the location of the libiconv.so library. If > > that is not desired, then GCC must be configured to link to a static > > libiconv.a instead, using either --with-libiconv-type=static or an > > in-tree build of libiconv. > > > > libstdc++-v3/ChangeLog: > > > > PR libstdc++/93602 > > * doc/xml/manual/prerequisites.xml: Document libiconv > > workarounds. > > * doc/html/manual/setup.html: Regenerate. > > * src/Makefile.am (CXXLINK): Add $(LTLIBICONV). > > * src/Makefile.in: Regenerate. > > --- > > diff --git a/libstdc++-v3/doc/xml/manual/prerequisites.xml b/libstdc++-v3/doc/xml/manual/prerequisites.xml > > index 22e90a7e79d..8799487c821 100644 > > --- a/libstdc++-v3/doc/xml/manual/prerequisites.xml > > +++ b/libstdc++-v3/doc/xml/manual/prerequisites.xml > > @@ -48,6 +48,56 @@ > > <varlistentry> > > <term>linux</term> > > > > + <listitem> > > + <para> > > + The 'gnu' locale model makes use of <function>iconv</function> > > + for character set conversions. The relevant functions are provided > > + by Glibc and so are always available, however they can also be > > + provided by the separate GNU libiconv library. If GNU libiconv is > > + found when GCC is built (e.g., because its headers are installed > > + in <filename class="directory">/usr/local/include</filename>) > > + then the <filename>libstdc++.so.6</filename> library will have a > > + run-time dependency on <filename>libiconv.so.2</filename>. > > + If you do not want that run-time dependency then you should do > > + one of the following: > > + </para> > > + <itemizedlist> > > + <listitem> > > + <para> > > + Uninstall the libiconv headers before building GCC. > > + Glibc already provides <function>iconv</function> so you should > > + not need libiconv anyway. > > + </para> > > + </listitem> > > + <listitem> > > + <para> > > + <link linkend="https://www.gnu.org/software/libiconv/#downloading"> > > + Download</link> the libiconv sources and extract them into the > > + top level of the GCC source tree, e.g., > > + </para> > > +<programlisting> > > +wget https://ftp.gnu.org/pub/gnu/libiconv/libiconv-1.16.tar.gz > > +tar xf libiconv-1.16.tar.gz > > +ln -s libiconv-1.16 libiconv > > +</programlisting> > > + <para> > > + This will build libiconv as part of building GCC and link to > > + it statically, so there is no <filename>libiconv.so.2</filename> > > + dependency. > > + </para> > > + </listitem> > > + <listitem> > > + <para> > > + Configure GCC with <option>--with-libiconv-type=static</option>. > > + This requires the static <filename>libiconv.a</filename> library, > > + which is not installed by default. You might need to reinstall > > + libiconv using the <option>--enable-static</option> configure > > + option to get the static library. > > + </para> > > + </listitem> > > + </itemizedlist> > > + </listitem> > > + > > <listitem> > > <para> > > If GCC 3.1.0 or later on is being used on GNU/Linux, an attempt > > diff --git a/libstdc++-v3/src/Makefile.am b/libstdc++-v3/src/Makefile.am > > index 18f57632c3d..9c3f4aca655 100644 > > --- a/libstdc++-v3/src/Makefile.am > > +++ b/libstdc++-v3/src/Makefile.am > > @@ -278,7 +278,9 @@ CXXLINK = \ > > $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \ > > --mode=link $(CXX) \ > > $(VTV_CXXLINKFLAGS) \ > > - $(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@ > > + $(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) \ > > + $(LTLDFLAGS) $(LTLIBICONV) \ > > + -o $@ > > > > # Symbol versioning for shared libraries. > > if ENABLE_SYMVERS > > >
On Thu, 21 Apr 2022 at 11:14, Yubin Ruan wrote: > > Hi, > > Will this be in GCC12? Unless the patch gets reverted, yes. GCC 12 hasn't branched from trunk yet, so everything on trunk will be in GCC 12. > > -- > Yubin > > On Wed, Apr 20, 2022 at 8:58 PM Jonathan Wakely via Libstdc++ > <libstdc++@gcc.gnu.org> wrote: > > > > Pushed to trunk now. > > > > On Wed, 13 Apr 2022 at 15:24, Jonathan Wakely via Libstdc++ > > <libstdc++@gcc.gnu.org> wrote: > > > > > > Tested x86_64-linux, without libiconv installed, with libiconv installed, > > > with libiconv installed but using an in-tree libiconv, with libiconv.a > > > installed and using --with-libiconv-type=static, and with libiconv.so > > > installed and using --without-libiconv-prefix (which still fails). > > > > > > I'm not entirely happy about the fact that libtool's LTLIBICONV adds an > > > rpath to libstdc++.so, but that can be avoided (as documented by this > > > patch) and I don't really see a better solution. Another option would be > > > to use -l:libiconv.a if configure defines LTLIBICONV to non-empty and > > > the linker supports it, which would *force* the use of a static lib. But > > > that seems unnecessarily hostile; not all users will dislike the rpath > > > solution. The proposed patch makes it Just Work™ for users who (for > > > whatever reason) have installed libiconv, while also allowing them to do > > > something more sensible if they care enough to do so. > > > > > > Thoughts? > > > > > > -- >8 -- > > > > > > This fixes missing libiconv symbols when libstdc++ is built on a system > > > that has libiconv installed. If the libiconv headers are found then > > > libstdc++ depends on libiconv_open etc instead of libc's iconv_open. But > > > without this fix libstdc++ is not linked to the libiconv library that > > > provides the definitions of those symbols. > > > > > > As discussed in PR 93602 this changed means that libstdc++.so.6 might > > > have an rpath pointing to the location of the libiconv.so library. If > > > that is not desired, then GCC must be configured to link to a static > > > libiconv.a instead, using either --with-libiconv-type=static or an > > > in-tree build of libiconv. > > > > > > libstdc++-v3/ChangeLog: > > > > > > PR libstdc++/93602 > > > * doc/xml/manual/prerequisites.xml: Document libiconv > > > workarounds. > > > * doc/html/manual/setup.html: Regenerate. > > > * src/Makefile.am (CXXLINK): Add $(LTLIBICONV). > > > * src/Makefile.in: Regenerate. > > > --- > > > diff --git a/libstdc++-v3/doc/xml/manual/prerequisites.xml b/libstdc++-v3/doc/xml/manual/prerequisites.xml > > > index 22e90a7e79d..8799487c821 100644 > > > --- a/libstdc++-v3/doc/xml/manual/prerequisites.xml > > > +++ b/libstdc++-v3/doc/xml/manual/prerequisites.xml > > > @@ -48,6 +48,56 @@ > > > <varlistentry> > > > <term>linux</term> > > > > > > + <listitem> > > > + <para> > > > + The 'gnu' locale model makes use of <function>iconv</function> > > > + for character set conversions. The relevant functions are provided > > > + by Glibc and so are always available, however they can also be > > > + provided by the separate GNU libiconv library. If GNU libiconv is > > > + found when GCC is built (e.g., because its headers are installed > > > + in <filename class="directory">/usr/local/include</filename>) > > > + then the <filename>libstdc++.so.6</filename> library will have a > > > + run-time dependency on <filename>libiconv.so.2</filename>. > > > + If you do not want that run-time dependency then you should do > > > + one of the following: > > > + </para> > > > + <itemizedlist> > > > + <listitem> > > > + <para> > > > + Uninstall the libiconv headers before building GCC. > > > + Glibc already provides <function>iconv</function> so you should > > > + not need libiconv anyway. > > > + </para> > > > + </listitem> > > > + <listitem> > > > + <para> > > > + <link linkend="https://www.gnu.org/software/libiconv/#downloading"> > > > + Download</link> the libiconv sources and extract them into the > > > + top level of the GCC source tree, e.g., > > > + </para> > > > +<programlisting> > > > +wget https://ftp.gnu.org/pub/gnu/libiconv/libiconv-1.16.tar.gz > > > +tar xf libiconv-1.16.tar.gz > > > +ln -s libiconv-1.16 libiconv > > > +</programlisting> > > > + <para> > > > + This will build libiconv as part of building GCC and link to > > > + it statically, so there is no <filename>libiconv.so.2</filename> > > > + dependency. > > > + </para> > > > + </listitem> > > > + <listitem> > > > + <para> > > > + Configure GCC with <option>--with-libiconv-type=static</option>. > > > + This requires the static <filename>libiconv.a</filename> library, > > > + which is not installed by default. You might need to reinstall > > > + libiconv using the <option>--enable-static</option> configure > > > + option to get the static library. > > > + </para> > > > + </listitem> > > > + </itemizedlist> > > > + </listitem> > > > + > > > <listitem> > > > <para> > > > If GCC 3.1.0 or later on is being used on GNU/Linux, an attempt > > > diff --git a/libstdc++-v3/src/Makefile.am b/libstdc++-v3/src/Makefile.am > > > index 18f57632c3d..9c3f4aca655 100644 > > > --- a/libstdc++-v3/src/Makefile.am > > > +++ b/libstdc++-v3/src/Makefile.am > > > @@ -278,7 +278,9 @@ CXXLINK = \ > > > $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \ > > > --mode=link $(CXX) \ > > > $(VTV_CXXLINKFLAGS) \ > > > - $(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@ > > > + $(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) \ > > > + $(LTLDFLAGS) $(LTLIBICONV) \ > > > + -o $@ > > > > > > # Symbol versioning for shared libraries. > > > if ENABLE_SYMVERS > > > > > >
diff --git a/libstdc++-v3/doc/xml/manual/prerequisites.xml b/libstdc++-v3/doc/xml/manual/prerequisites.xml index 22e90a7e79d..8799487c821 100644 --- a/libstdc++-v3/doc/xml/manual/prerequisites.xml +++ b/libstdc++-v3/doc/xml/manual/prerequisites.xml @@ -48,6 +48,56 @@ <varlistentry> <term>linux</term> + <listitem> + <para> + The 'gnu' locale model makes use of <function>iconv</function> + for character set conversions. The relevant functions are provided + by Glibc and so are always available, however they can also be + provided by the separate GNU libiconv library. If GNU libiconv is + found when GCC is built (e.g., because its headers are installed + in <filename class="directory">/usr/local/include</filename>) + then the <filename>libstdc++.so.6</filename> library will have a + run-time dependency on <filename>libiconv.so.2</filename>. + If you do not want that run-time dependency then you should do + one of the following: + </para> + <itemizedlist> + <listitem> + <para> + Uninstall the libiconv headers before building GCC. + Glibc already provides <function>iconv</function> so you should + not need libiconv anyway. + </para> + </listitem> + <listitem> + <para> + <link linkend="https://www.gnu.org/software/libiconv/#downloading"> + Download</link> the libiconv sources and extract them into the + top level of the GCC source tree, e.g., + </para> +<programlisting> +wget https://ftp.gnu.org/pub/gnu/libiconv/libiconv-1.16.tar.gz +tar xf libiconv-1.16.tar.gz +ln -s libiconv-1.16 libiconv +</programlisting> + <para> + This will build libiconv as part of building GCC and link to + it statically, so there is no <filename>libiconv.so.2</filename> + dependency. + </para> + </listitem> + <listitem> + <para> + Configure GCC with <option>--with-libiconv-type=static</option>. + This requires the static <filename>libiconv.a</filename> library, + which is not installed by default. You might need to reinstall + libiconv using the <option>--enable-static</option> configure + option to get the static library. + </para> + </listitem> + </itemizedlist> + </listitem> + <listitem> <para> If GCC 3.1.0 or later on is being used on GNU/Linux, an attempt diff --git a/libstdc++-v3/src/Makefile.am b/libstdc++-v3/src/Makefile.am index 18f57632c3d..9c3f4aca655 100644 --- a/libstdc++-v3/src/Makefile.am +++ b/libstdc++-v3/src/Makefile.am @@ -278,7 +278,9 @@ CXXLINK = \ $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \ --mode=link $(CXX) \ $(VTV_CXXLINKFLAGS) \ - $(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@ + $(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) \ + $(LTLDFLAGS) $(LTLIBICONV) \ + -o $@ # Symbol versioning for shared libraries. if ENABLE_SYMVERS