[PATCH] New configuration options to enable additional executable/startfile/shared library prefixes

[Michael Meissner <meissner at linux dot vnet dot ibm dot com>]

I may have submitted this shortly before the Caudren, and it got lost.

This patch adds 4 additional configuration switches, that allow the person
building the compiler to add additional prefixes to search for additional
executables and startfiles.

If the backend has the appropriate tweaks installed, it will also add
additional prefixes to search for the dynamic linker.  At the moment, only the
PowerPC Linux port has the modifications.  It is fairly easy to modify other
targets if desired.

The motivation for this comes from the IBM Advance Toolchain (AT), which runs
on PowerPC Linux 64-bit system running on IBM server class machines (power4
through power7).  AT provides its own version of the standard libraries and its
own dynamic linker.  Unlike a cross compiler environment where you want to use
--sysroot to not reference any of the host libraries, a release compiler like
this wants to be able to use the system libraries and include files if it
doesn't provide for them in the release.

The released version of the AT has the sources modified so that it uses the
pathnames for the release instead of the standard library and executable
pathnames.  When we are doing development, it would be convenient to have the
compilers that we build target the AT directly without having to use the
appropriate linker/include options to use the AT executables, libraries, and
dynamic linker.

I have built compilers without these patches, with the patches but not adding
the configuration options, and with these patches using the configuration
options.  The compilers all bootstrapped.  In running the regression suite
there are two differences when the option is used:

gcc.dg/cproj-fails-with-broken-glibc.c fails on SLES 11SP1, but works fine when
linked with the AT 6.0 libraries, which is expected, since the AT library is
based on a newer baseline thatn Sles 11SP1.

gfortran.dg/bessel_6.f90 fails when using the Advance Toolchain 6.0 libraries,
due to the bessel jn function returning slightly differenct values, which
causes the test to fail.  If I use the Advance Toolchain 5.0 library, it works
fine.  I have entered the bug into AT bugzilla.

Both of these errors show that when the options are used, it does in fact use
the alternative library instead of the system libraries.

I have broken these patches into 2 attachments.  The first attachment
(gcc-power7.patch369c) are the machine independent changes.  The second
attachment (gcc-power7.patch369d) are just the powerpc specific changes.

Are these patches ok to install?

2012-11-01  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* configure.ac (--with-extra-prefix=): Add configure time switches
	to add addition prefix directories for the compiler to search for
	extra executables, startfiles, and directories to add to the list
	of shared library locations.
	(--with-extra-exec-prefix=): Likewise.
	(--with-extra-startfile-prefix=): Likewise.
	(--with-extra-rpath-prefix=): Likewise.
	* configure: Regenerate.

	* doc/install.texi (--with-extra-prefix=): Document new configure
	switches.
	(--with-extra-exec-prefix=): Likewise.
	(--with-extra-startfile-prefix=): Likewise.
	(--with-extra-rpath-prefix=): Likewise.

	* gcc.c (LINK_RPATH_DIRS_SPEC): Add support for configuration time
	additional executable, startfile, and shared library location
	prefixes.  Add %find-dynamic-linker(), %extra-rpath-dirs(),
	%extra-cpu-dirs() as spec functions.
	(LINK_COMMAND_SPEC): Likewise.
	(CONFIGURE_STARTFILE_PREFIX): Likewise.
	(configure_startfile_prefix): Likewise.
	(configure_exec_prefix): Likewise.
	(static_spec_functions): Likewise.
	(IS_STD_DIR): Likewise.
	(config_rpath): Likewise.
	(build_rpath_or_cpu_dirs): Likewise.
	(extra_rpath_dirs_spec_function): Likewsie.
	(extra_cpu_dirs_spec_function): Likewise.
	(find_dynamic_linker_spec_function): Likewise.
	(add_multiple_prefix): New function that is like add_prefix, but
	splits the prefix at PATH_SEPARATOR.
	(process_command): Simplify processing COMPILER_PATH, LPATH, and
	LIBRARY_PATH_ENV environment variables by using the function
	add_multiple_prefix to do the splitting of the separate prefixes.
	Add support for the configuration switch to add new executable,
	startfile, and shared library prefixes.

	* gcc.h (extra_cpu_dirs_spec_function): Add declaration.

	* config.in (CONFIGURE_EXEC_PREFIX): Add defines for the configure
	switches to add executable, startfile, and shared library
	configuration directories.
	(CONFIGURE_STARTFILE_PREFIX): Likewise.
	(CONFIGURE_RPATH_PREFIX): Likewise.

	* config/rs6000/x-rs6000 (driver-rs6000.o): Add $(GCC_H)
	dependency.

	* config/rs6000/linux64.h (GLIBC_DYNAMIC_LINKER32): If
	--with-extra-startfile-prefix or --with-extra-prefix was used, use
	%find-dynamic-linker() to find the dynamic linker in the startfile
	prefixes.
	(GLIBC_DYNAMIC_LINKER64): Likewise.
	(LINUX_EXTRA_STATIC_LIBDIRS64): Likewise.
	(LINK_OS_LINUX_SPEC32): Likewise.
	(LINK_OS_LINUX_SPEC64): Likewise.
	* config/rs6000/rs6000.h (EXTRA_SPEC_FUNCTIONS): Likewise.
	(LOCAL_CPU_EXTR_SPEC_FUNCTIONS): Likewise.
	* config/rs6000/sysv4.h (GLIBC_DYNAMIC_LINKER): Likewise.
	(LINUX_EXTRA_STATIC_LIBDIRS32): Likewise.
	(LINK_OS_LINUX_SPEC): Likewise.
	(rs6000_extra_static_libdirs): Likewise.
	(SUBTARGET_EXTRA_SPEC_FUNCTIONS): Likewise.

	* config/rs6000/driver-rs6000.c (toplevel): Include gcc.h.
	(rs6000_extra_static_libdirs): If we have extra configure
	startfile prefixes, look for a machine specific file as a
	subdirectory in the startfile prefixes if the user used
	-mcpu=<xxx>.

-- 
Michael Meissner, IBM
5 Technology Place Drive, M/S 2757, Westford, MA 01886-3141, USA
meissner@linux.vnet.ibm.com	fax +1 (978) 399-6899

Attachment: gcc-power7.patch369c
Description: Text document

Attachment: gcc-power7.patch369d
Description: Text document