Hi! Ping, after another month. Reposting the patches below; freshly re-tested, both to cause no change if the new configure options are not used, and to do the right thing if they are.
On Tue, 12 Nov 2013 14:52:37 +0100, I wrote:
> Could a global maintainer or build machinery maintainer please review the
> two unreviewed patches posted in this series?
>
> On Mon, 4 Nov 2013 10:13:39 -0800, Cary Coutant <ccout...@google.com> wrote:
> > >> Ping. To sum it up, with these patches applied, there are no changes for
> > >> a "regular" build (not using the new configure options). On the other
> > >> hand, configuring GCC as described, it is possible use the 32-bit x86
> > >> linker for/with a x86_64 build, and get the very same GCC test results as
> > >> when using a x86_64 linker.
> >
> > Sorry, I've been hoping someone with more global approval authority
> > would respond.
> >
> > > Allow overriding the libiberty used for building the LTO plugin.
> > >
> > > lto-plugin/
> > > * configure.ac (--with-libiberty): New configure option.
> > > * configure: Regenerate.
> > > * Makefile.am (libiberty, libiberty_pic): New variables.
> > > (liblto_plugin_la_LIBADD, liblto_plugin_la_LDFLAGS)
> > > (liblto_plugin_la_DEPENDENCIES): Use them.
> > > * Makefile.in: Regenerate.
> >
> > These look OK to me.
> >
> > > Allow for overriding a module's srcdir.
> > >
> > > * Makefile.tpl (configure-[+prefix+][+module+])
> > > (configure-stage[+id+]-[+prefix+][+module+]): Allow for
> > > overriding a module's srcdir.
> > > * Makefile.in: Regenerate.
> >
> > These look OK, but I think a global maintainer or build machinery
> > maintainer should give approval.
> >
> > > Non-host system configuration for linker plugins.
> > >
> > > * configure.ac (--enable-linker-plugin-flags)
> > > (--enable-linker-plugin-configure-flags): New flags.
> > > (configdirs): Conditionally add libiberty-linker-plugin.
> > > * configure: Regenerate.
> > > * Makefile.def (host_modules): Add libiberty-linker-plugin.
> > > (host_modules) <lto-plugin>: Pay attention to
> > > @extra_linker_plugin_flags@ and
> > > @extra_linker_plugin_configure_flags@.
> > > (all-lto-plugin): Also depend on all-libiberty-linker-plugin.
> > > * Makefile.in: Regenerate.
> > > gcc/
> > > * doc/install.texi (--enable-linker-plugin-flags)
> > > (--enable-linker-plugin-configure-flags): Document new flags.
> >
> > Same here.
commit d09a4afcf55cde981ec9dad86950be5ade51f9eb
Author: Thomas Schwinge <tho...@codesourcery.com>
Date: Sun Oct 13 16:15:56 2013 +0200
Allow overriding the libiberty used for building the LTO plugin.
lto-plugin/
* configure.ac (--with-libiberty): New configure option.
* configure: Regenerate.
* Makefile.am (libiberty, libiberty_pic): New variables.
(liblto_plugin_la_LIBADD, liblto_plugin_la_LDFLAGS)
(liblto_plugin_la_DEPENDENCIES): Use them.
* Makefile.in: Regenerate.
diff --git lto-plugin/Makefile.am lto-plugin/Makefile.am
index b24015e..8b7bb54 100644
--- lto-plugin/Makefile.am
+++ lto-plugin/Makefile.am
@@ -15,17 +15,19 @@ libexecsub_LTLIBRARIES = liblto_plugin.la
gcc_build_dir = ../$(host_subdir)/gcc
in_gcc_libs = $(foreach lib, $(libexecsub_LTLIBRARIES),
$(gcc_build_dir)/$(lib))
-# Can be removed when libiberty becomes a normal convenience library
-Wc=-Wc,
-
liblto_plugin_la_SOURCES = lto-plugin.c
+# Note that we intentionally override the bindir supplied by ACX_LT_HOST_FLAGS.
+liblto_plugin_la_LDFLAGS = $(lt_host_flags) -module -bindir $(libexecsubdir)
+# Can be simplified when libiberty becomes a normal convenience library.
+libiberty=$(with_libiberty)/libiberty.a
+libiberty_pic=$(with_libiberty)/pic/libiberty.a
+Wc=-Wc,
liblto_plugin_la_LIBADD = \
- $(if $(wildcard
../libiberty/pic/libiberty.a),$(Wc)../libiberty/pic/libiberty.a,)
-# Note that we intentionally override the bindir supplied by ACX_LT_HOST_FLAGS
-liblto_plugin_la_LDFLAGS = $(lt_host_flags) -module -bindir $(libexecsubdir) \
- $(if $(wildcard
../libiberty/pic/libiberty.a),,-Wc,../libiberty/libiberty.a)
-liblto_plugin_la_DEPENDENCIES = $(if $(wildcard \
- ../libiberty/pic/libiberty.a),../libiberty/pic/libiberty.a,)
+ $(if $(wildcard $(libiberty_pic)),$(Wc)$(libiberty_pic),)
+liblto_plugin_la_LDFLAGS += \
+ $(if $(wildcard $(libiberty_pic)),,-Wc,$(libiberty))
+liblto_plugin_la_DEPENDENCIES = \
+ $(if $(wildcard $(libiberty_pic)),$(libiberty_pic),)
all-local: $(in_gcc_libs)
diff --git lto-plugin/Makefile.in lto-plugin/Makefile.in
[...]
diff --git lto-plugin/configure lto-plugin/configure
[...]
diff --git lto-plugin/configure.ac lto-plugin/configure.ac
index 9a418d2..b73fabb 100644
--- lto-plugin/configure.ac
+++ lto-plugin/configure.ac
@@ -4,6 +4,11 @@ AC_CANONICAL_SYSTEM
GCC_TOPLEV_SUBDIRS
AM_INIT_AUTOMAKE([foreign no-dist])
AM_MAINTAINER_MODE
+AC_ARG_WITH(libiberty,
+ [AS_HELP_STRING([--with-libiberty=PATH],
+ [specify the directory where to find libiberty [../libiberty]])],
+ [], with_libiberty=../libiberty)
+AC_SUBST(with_libiberty)
AC_PROG_CC
AC_SYS_LARGEFILE
ACX_PROG_CC_WARNING_OPTS([-Wall], [ac_lto_plugin_warn_cflags])
commit c02c5075066e1e4e461efa0752d56eab3ac301de
Author: Thomas Schwinge <tho...@codesourcery.com>
Date: Sun Oct 13 14:36:07 2013 +0200
Allow for overriding a module's srcdir.
* Makefile.tpl (configure-[+prefix+][+module+])
(configure-stage[+id+]-[+prefix+][+module+]): If specified, use
"module_srcdir" instead of "module" for locating a module's srcdir.
* Makefile.in: Regenerate.
diff --git Makefile.in Makefile.in
[...]
diff --git Makefile.tpl Makefile.tpl
index 92f3f61..d505b5e 100644
--- Makefile.tpl
+++ Makefile.tpl
@@ -1002,12 +1002,13 @@ configure-[+prefix+][+module+]: [+ IF bootstrap +][+
ELSE +]
*) topdir=`echo [+subdir+]/[+module+]/ | \
sed -e 's,\./,,g' -e 's,[^/]*/,../,g' `$(srcdir) ;; \
esac; \
- srcdiroption="--srcdir=$${topdir}/[+module+]"; \
- libsrcdir="$$s/[+module+]"; \
+ module_srcdir=[+? module_srcdir (get "module_srcdir") (get "module")+];
\
[+ IF no-config-site +]rm -f no-such-file || : ; \
- CONFIG_SITE=no-such-file [+ ENDIF +]$(SHELL) $${libsrcdir}/configure \
+ CONFIG_SITE=no-such-file [+ ENDIF +]$(SHELL) \
+ $$s/$$module_srcdir/configure \
+ --srcdir=$${topdir}/$$module_srcdir \
[+args+] --build=${build_alias} --host=[+host_alias+] \
- --target=[+target_alias+] $${srcdiroption} [+extra_configure_flags+] \
+ --target=[+target_alias+] [+extra_configure_flags+] \
|| exit 1
@endif [+prefix+][+module+]
@@ -1055,12 +1056,12 @@ configure-stage[+id+]-[+prefix+][+module+]:
*) topdir=`echo [+subdir+]/[+module+]/ | \
sed -e 's,\./,,g' -e 's,[^/]*/,../,g' `$(srcdir) ;; \
esac; \
- srcdiroption="--srcdir=$${topdir}/[+module+]"; \
- libsrcdir="$$s/[+module+]"; \
- $(SHELL) $${libsrcdir}/configure \
+ module_srcdir=[+? module_srcdir (get "module_srcdir") (get "module")+];
\
+ $(SHELL) $$s/$$module_srcdir/configure \
+ --srcdir=$${topdir}/$$module_srcdir \
[+args+] --build=${build_alias} --host=[+host_alias+] \
- --target=[+target_alias+] $${srcdiroption} [+ IF prev +]\
- --with-build-libsubdir=$(HOST_SUBDIR) [+ ENDIF prev +]\
+ --target=[+target_alias+] \
+ [+ IF prev +] --with-build-libsubdir=$(HOST_SUBDIR) [+ ENDIF prev +] \
$(STAGE[+id+]_CONFIGURE_FLAGS)[+ IF extra_configure_flags +] \
[+extra_configure_flags+][+ ENDIF extra_configure_flags +]
@endif [+prefix+][+module+]-bootstrap
commit 9292bf8e327e2c729677eaaac2c263456cb77aec
Author: Thomas Schwinge <tho...@codesourcery.com>
Date: Sun Oct 13 20:05:14 2013 +0200
Non-host system configuration for linker plugins.
* configure.ac (--enable-linker-plugin-configure-flags)
(--enable-linker-plugin-flags): New flags.
(configdirs): Conditionally add libiberty-linker-plugin.
* configure: Regenerate.
* Makefile.def (host_modules): Add libiberty-linker-plugin.
(host_modules) <lto-plugin>: Pay attention to
@extra_linker_plugin_flags@ and
@extra_linker_plugin_configure_flags@.
(all-lto-plugin): Also depend on all-libiberty-linker-plugin.
* Makefile.in: Regenerate.
gcc/
* doc/install.texi (--enable-linker-plugin-configure-flags)
(--enable-linker-plugin-flags): Document new flags.
diff --git Makefile.def Makefile.def
index 32296d1..2a64866 100644
--- Makefile.def
+++ Makefile.def
@@ -85,6 +85,14 @@ host_modules= { module= libdecnumber; bootstrap=true; };
host_modules= { module= libgui; };
host_modules= { module= libiberty; bootstrap=true;
extra_configure_flags='@extra_host_libiberty_configure_flags@';};
+// Linker plugins may need their own build of libiberty; see
+// gcc/doc/install.texi. We take care that this build of libiberty doesn't get
+// installed. It's a helper library for linker plugins, so we pay attention to
+// @extra_linker_plugin_flags@ and @extra_linker_plugin_configure_flags@.
+host_modules= { module= libiberty-linker-plugin; bootstrap=true;
+ module_srcdir=libiberty;
+ extra_configure_flags='@extra_host_libiberty_configure_flags@
--disable-install-libiberty @extra_linker_plugin_flags@
@extra_linker_plugin_configure_flags@';
+ extra_make_flags='@extra_linker_plugin_flags@'; };
// We abuse missing to avoid installing anything for libiconv.
host_modules= { module= libiconv;
extra_configure_flags='--disable-shared';
@@ -111,7 +119,8 @@ host_modules= { module= libtermcap; no_check=true;
host_modules= { module= utils; no_check=true; };
host_modules= { module= gnattools; };
host_modules= { module= lto-plugin; bootstrap=true;
- extra_configure_flags=--enable-shared; };
+ extra_configure_flags='--enable-shared
@extra_linker_plugin_flags@ @extra_linker_plugin_configure_flags@';
+ extra_make_flags='@extra_linker_plugin_flags@'; };
target_modules = { module= libstdc++-v3;
bootstrap=true;
@@ -337,7 +346,10 @@ dependencies = { module=all-fixincludes; on=all-libiberty;
};
dependencies = { module=all-gnattools; on=all-target-libada; };
+// Depending on the specific configuration, the LTO plugin will either use the
+// generic libiberty build or the specific build for linker plugins.
dependencies = { module=all-lto-plugin; on=all-libiberty; };
+dependencies = { module=all-lto-plugin; on=all-libiberty-linker-plugin; };
dependencies = { module=all-utils; on=all-libiberty; };
diff --git Makefile.in Makefile.in
[...]
diff --git configure configure
[...]
diff --git configure.ac configure.ac
index 30190d6..1fa99c3 100644
--- configure.ac
+++ configure.ac
@@ -1731,6 +1731,19 @@ ACX_ELF_TARGET_IFELSE([# ELF platforms build the
lto-plugin always.
esac
])
+AC_ARG_ENABLE(linker-plugin-configure-flags,
+ [AS_HELP_STRING([[--enable-linker-plugin-configure-flags=FLAGS]],
+ [additional flags for configuring linker plugins @<:@none@:>@])],
+ extra_linker_plugin_configure_flags=$enableval,
+ extra_linker_plugin_configure_flags=)
+AC_SUBST(extra_linker_plugin_configure_flags)
+AC_ARG_ENABLE(linker-plugin-flags,
+ [AS_HELP_STRING([[--enable-linker-plugin-flags=FLAGS]],
+ [additional flags for configuring and building linker plugins
@<:@none@:>@])],
+ extra_linker_plugin_flags=$enableval,
+ extra_linker_plugin_flags=)
+AC_SUBST(extra_linker_plugin_flags)
+
# By default, C and C++ are the only stage 1 languages.
stage1_languages=,c,
@@ -2133,6 +2146,21 @@ for i in ${target_configdirs_all} ; do
fi
done
+# libiberty-linker-plugin is special: it doesn't have its own source directory,
+# so we have to add it after the preceding checks.
+if test x"$extra_linker_plugin_flags$extra_linker_plugin_configure_flags" != x
+then
+ case " $configdirs " in
+ *" libiberty "*)
+ # If we can build libiberty, we can also build libiberty-linker-plugin.
+ configdirs="$configdirs libiberty-linker-plugin"
+
extra_linker_plugin_configure_flags="$extra_linker_plugin_configure_flags \
+ --with-libiberty=../libiberty-linker-plugin";;
+ *)
+ AC_MSG_ERROR([libiberty missing]);;
+ esac
+fi
+
# Produce a warning message for the subdirs we can't configure.
# This isn't especially interesting in the Cygnus tree, but in the individual
# FSF releases, it's important to let people know when their machine isn't
diff --git gcc/doc/install.texi gcc/doc/install.texi
index 71aa7fc..19f54c4 100644
--- gcc/doc/install.texi
+++ gcc/doc/install.texi
@@ -1775,6 +1775,25 @@ GLIBC 2.11 or above, otherwise disabled.
Enable support for link-time optimization (LTO). This is enabled by
default, and may be disabled using @option{--disable-lto}.
+@item --enable-linker-plugin-configure-flags=FLAGS
+@itemx --enable-linker-plugin-flags=FLAGS
+By default, linker plugins (such as the LTO plugin) are built for the
+host system architecture. For the case that the linker has a
+different (but run-time compatible) architecture, these flags can be
+specified to build plugins that are compatible to the linker. For
+example, if you are building GCC for a 64-bit x86_64
+(@samp{x86_64-unknown-linux-gnu}) host system, but have a 32-bit x86
+GNU/Linux (@samp{i686-pc-linux-gnu}) linker executable (which is
+executable on the former system), you can configure GCC as follows for
+getting compatible linker plugins:
+
+@smallexample
+% @var{srcdir}/configure \
+ --host=x86_64-unknown-linux-gnu \
+ --enable-linker-plugin-configure-flags=--host=i686-pc-linux-gnu \
+ --enable-linker-plugin-flags='CC=gcc\ -m32\
-Wl,-rpath,[...]/i686-pc-linux-gnu/lib'
+@end smallexample
+
@item --with-plugin-ld=@var{pathname}
Enable an alternate linker to be used at link-time optimization (LTO)
link time when @option{-fuse-linker-plugin} is enabled.
Grüße,
Thomas
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