[2/2] Add gcc-ar, gcc-ranlib, gcc-ld wrappers v2

Message ID 20101029190349.GB12649@basil.fritz.box
State New
Headers show

Commit Message

Andi Kleen Oct. 29, 2010, 7:03 p.m.
On Fri, Oct 29, 2010 at 11:46:01AM -0700, H.J. Lu wrote:
> On Fri, Oct 29, 2010 at 11:41 AM, Andi Kleen <andi@firstfloor.org> wrote:
> >>
> >> exec $AR -s --plugin `$BINDIR/gcc -print-lto-plugin` "$@"
> >
> > Yes you're right of course. Fixed.
> gcc-ranlib have the same problem. Don't we also need "gcc -nm"?

I fixed both. I can add a nm in the same way if people want.

I personally didn't need it because i have an own utility to dump the 
lto symbol tables that I typically use.

Current version appended.


From: Andi Kleen <ak@linux.intel.com>
Subject: [PATCH] Add gcc-ar, gcc-ranlib, gcc-ld wrappers v3

[Updated version, see changelog below. I decided to drop
gcc-ld for now because that one seemed to be problematic
and is only needed for some specific project. I guess I can
keep it separate.]

Earlier review resulted in a request for having gcc-... wrappers
to handle the LTO symbol tables for ranlib/ar. This is needed for slim
lto files, because these tools cannot read the symbol table
otherwise. Essentially they just call binutils with
the LTO plugin specified.

Other compilers with LTO support tend to have similar tools.

This patch implements those wrappers.

The wrappers are also needed for a LTO slim of gcc. Right now
they have to be manually specified for that.

The wrappers require uptodate binutils (the upcoming release)
with plugin support enabled.  There is currently no autoconf
support to detect that. The wrappers query the gcc driver
in an attempt to handle cross compilation and so naming everywhere

v2: drop gcc-ld for now. support relocated installation trees.
v3: fix typo, support xgcc


2010-10-26  Andi Kleen  <ak@linux.intel.com>

	(lto.all.cross, lto.start.cross): Add dependency to LTO_WRAPPERS.
	(lto.install.common): Install wrappers.
	(lto.mostlyclean): Clean wrappers.
	* gcc-ar, gcc-ranlib.in: Add.


2010-10-26  Andi Kleen  <ak@linux.intel.com>

	* doc/invoke.texi (gcc-ar, gcc-ranlib): Document.


Ralf Wildenhues Oct. 29, 2010, 7:09 p.m. | #1
* Andi Kleen wrote on Fri, Oct 29, 2010 at 09:03:49PM CEST:
> --- /dev/null
> +++ b/gcc/lto/gcc-ar
> @@ -0,0 +1,18 @@
> +#!/bin/sh
> +# wrapper for ar with GCC LTO support
> +# requires binutils 2.21+
> +
> +BASE=`readlink -f $0`
> +BINDIR=`dirname $BASE`
> +
> +if [ -x "$BINDIR/xgcc" ] ; then
> +	GCC=xgcc
> +else
> +	GCC=gcc
> +	ARG=
> +fi
> +
> +AR=${AR:-`"$BINDIR/$GCC" -print-prog-name=ar`}

> +exec $AR --plugin `$BINDIR/$GCC $ARG -print-lto-plugin` "$@"

If you're double-quoting $BINDIR before in this script for a reason,
then you should do so here as well.  Likewise in the gcc-ranlib script.

Joseph Myers Oct. 29, 2010, 7:34 p.m. | #2
On Fri, 29 Oct 2010, Andi Kleen wrote:

> +if [ -x "$BINDIR/xgcc" ] ; then
> +	GCC=xgcc
> +else
> +	GCC=gcc

No, it's not "gcc" in a cross toolchain or likely in GNU/Linux 
distribution toolchains.  It's gcc as modified by 
$(program_transform_name).  And if someone happens to have "xgcc" in their 
installation directory that should not affect how the program behaves; at 
most, "xgcc" should be a fallback if the expected name is not found, but 
actually I don't think working in a GCC build directory is important here 
(we should move towards staged installation to let parts of GCC find each 
other before the final install).

$ gcc -v
Using built-in specs.
Target: i686-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 
4.4.4-14ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs 
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr 
--program-suffix=-4.4 --enable-shared --enable-multiarch 
--enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib 
--without-included-gettext --enable-threads=posix 
--with-gxx-include-dir=/usr/include/c++/4.4 --libdir=/usr/lib --enable-nls 
--with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug 
--enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i686 
--with-tune=generic --enable-checking=release --build=i686-linux-gnu 
--host=i686-linux-gnu --target=i686-linux-gnu
Thread model: posix
gcc version 4.4.5 (Ubuntu/Linaro 4.4.4-14ubuntu5) 

That's system GCC on Ubuntu Maverick, note the --program-suffix to support 
simultaneous installation of multiple versions.

All the previous comments that you should be using C wrappers still apply.


diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index d6784ad..5cae0e4 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -7565,6 +7565,9 @@  be exported, it is possible to combine @option{-flto} and
 interprocedural optimizers to use more aggressive assumptions which
 may lead to improved optimization opportunities.
+In some cases you may need to use the @command{gcc-ar} and 
+@command{gcc-ranlib} commands to manage ar files of LTO objects. 
 Regarding portability: the current implementation of LTO makes no
 attempt at generating bytecode that can be ported between different
 types of hosts.  The bytecode files are versioned and there is a
diff --git a/gcc/lto/Make-lang.in b/gcc/lto/Make-lang.in
index 2dc6409..56f126d 100644
--- a/gcc/lto/Make-lang.in
+++ b/gcc/lto/Make-lang.in
@@ -28,16 +28,29 @@  LTO_H = lto/lto.h $(HASHTAB_H)
 LINKER_PLUGIN_API_H = $(srcdir)/../include/plugin-api.h
 LTO_TREE_H = lto/lto-tree.h $(LINKER_PLUGIN_API_H)
+AR_INSTALL_NAME := $(shell echo gcc-ar|sed '$(program_transform_name)')
+RANLIB_INSTALL_NAME := $(shell echo gcc-ranlib|sed '$(program_transform_name)')
+ifeq ($(enable_plugin),yes)
+LTO_WRAPPERS = lto/gcc-ar lto/gcc-ranlib
 # Rules
 # These hooks are used by the main GCC Makefile.  Consult that
 # Makefile for documentation.
-lto.all.cross: $(LTO_EXE)
-lto.start.encap: $(LTO_EXE)
+lto.all.cross: $(LTO_EXE) $(LTO_WRAPPERS)
+lto.start.encap: $(LTO_EXE) $(LTO_WRAPPERS)
+ifeq ($(enable_plugin),yes)
+	$(INSTALL_SCRIPT) lto/gcc-ar $(DESTDIR)$(bindir)/$(AR_INSTALL_NAME)
+	$(INSTALL_SCRIPT) lto/gcc-ranlib $(DESTDIR)$(bindir)/$(RANLIB_INSTALL_NAME)
diff --git a/gcc/lto/gcc-ar b/gcc/lto/gcc-ar
new file mode 100755
index 0000000..892a0c0
--- /dev/null
+++ b/gcc/lto/gcc-ar
@@ -0,0 +1,18 @@ 
+# wrapper for ar with GCC LTO support
+# requires binutils 2.21+
+BASE=`readlink -f $0`
+BINDIR=`dirname $BASE`
+if [ -x "$BINDIR/xgcc" ] ; then
+	GCC=xgcc
+	GCC=gcc
+	ARG=
+AR=${AR:-`"$BINDIR/$GCC" -print-prog-name=ar`}
+exec $AR --plugin `$BINDIR/$GCC $ARG -print-lto-plugin` "$@"
diff --git a/gcc/lto/gcc-ranlib b/gcc/lto/gcc-ranlib
new file mode 100644
index 0000000..d8482cc
--- /dev/null
+++ b/gcc/lto/gcc-ranlib
@@ -0,0 +1,18 @@ 
+# wrapper for ranlib with GCC LTO support
+# requires binutils 2.21+
+BASE=`readlink -f $0`
+BINDIR=`dirname $BASE`
+if [ -x "$BINDIR/xgcc" ] ; then
+	GCC=xgcc
+	GCC=gcc
+	ARG=
+AR=${AR:-`"$BINDIR/$GCC" -print-prog-name=ar`}
+exec $AR -s --plugin `$BINDIR/$GCC $ARG -print-lto-plugin` "$@"