Re: [PATCH] configure: Add new --enable-install-elfh option.

[Mark Wielaard <mark@klomp.org>]

Hi Ulf,

On Thu, Jan 24, 2019 at 06:53:15PM +0100, Mark Wielaard wrote:
> On Fri, 2019-01-18 at 14:03 +0000, Ulf Hermann wrote:
> > I think you should also adapt tests/Makefile.am to use our own elf.h
> > in 
> > this case. See https://codereview.qt-project.org/#/c/187812/25 for
> > my 
> > solution to this.
> 
> Yes, it should indeed.
> I used a slightly different solution though.
> It relies on the default include flags already including the srcdirs.
> Does that work for your use case too? (See revised patch attached.)

Please let me know if you have any more comments or suggestions.
I like to push this to master.

> I looked at the features.h tweak also in your patch.
> But I am not comfortable including something like that.
> It feels like it needs a different test (whether we are actually on a
> POSIX system or not). And I am not sure it really should define uid_t,
> gid_t, mode_t, and pid_t. Those normally don't come from features.h
> (they would come from sys/types.h).

Thanks,

Mark

> From 86f9481187bccb78b2533674bb905a0de1a03abf Mon Sep 17 00:00:00 2001
> From: Mark Wielaard <mark@klomp.org>
> Date: Fri, 18 Jan 2019 14:18:22 +0100
> Subject: [PATCH] configure: Add new --enable-install-elfh option.
> 
> We explicitly test (with system-elf-libelf) that our include headers
> work with the system elf.h header. But it might be helpful to install
> the elf.h file for a private install. Our elf.h header really is just
> a copy of the latest glibc elf.h. But it might be newer and include
> more constants than the system installed elf.h.
> 
> Add a new configure option --enable-install-elfh to install elf.h.
> But warn when it is enabled for the default /usr or /usr/local prefix
> because it might clash with the glibc/system elf.h header in that case.
> 
> Signed-off-by: Mark Wielaard <mark@klomp.org>
> ---
>  ChangeLog          |  4 ++++
>  configure.ac       | 12 ++++++++++++
>  libelf/ChangeLog   |  5 +++++
>  libelf/Makefile.am | 13 ++++++++++---
>  tests/ChangeLog    |  5 +++++
>  tests/Makefile.am  |  4 +++-
>  6 files changed, 39 insertions(+), 4 deletions(-)
> 
> diff --git a/ChangeLog b/ChangeLog
> index 45418a0..148ce77 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,7 @@
> +2019-01-18  Mark Wielaard  <mark@klomp.org>
> +
> +	* configure.ac: Add new --enable-install-elfh.
> +
>  2018-07-04  Ross Burton <ross.burton@intel.com>
>  
>  	* configure.ac: Check for gawk.
> diff --git a/configure.ac b/configure.ac
> index b89b867..7d4e69d 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -323,6 +323,11 @@ if test "$use_valgrind" = yes; then
>  fi
>  AM_CONDITIONAL(USE_VALGRIND, test "$use_valgrind" = yes)
>  
> +AC_ARG_ENABLE([install-elfh],
> +AS_HELP_STRING([--enable-install-elfh],[install elf.h in include dir]),
> +               [install_elfh=$enableval], [install_elfh=no])
> +AM_CONDITIONAL(INSTALL_ELFH, test "$install_elfh" = yes)
> +
>  AM_CONDITIONAL(BUILD_STATIC, [dnl
>  test "$use_gprof" = yes -o "$use_gcov" = yes])
>  
> @@ -658,6 +663,7 @@ AC_MSG_NOTICE([
>  
>    NOT RECOMMENDED FEATURES (should all be no)
>      Experimental thread safety         : ${use_locks}
> +    install elf.h                      : ${install_elfh}
>  
>    OTHER FEATURES
>      Deterministic archives by default  : ${default_ar_deterministic}
> @@ -673,3 +679,9 @@ AC_MSG_NOTICE([
>      use rpath in tests                 : ${tests_use_rpath}
>      test biarch                        : ${utrace_cv_cc_biarch}
>  ])
> +
> +if test "$install_elfh" = yes; then
> +  if test "${prefix}" = "/usr/local" -o "${prefix}" = "/usr"; then
> +    AC_MSG_WARN([installing elf.h in ${includedir} might conflict with glibc/system elf.h])
> +  fi
> +fi
> diff --git a/libelf/ChangeLog b/libelf/ChangeLog
> index 5783f0c..b89e93f 100644
> --- a/libelf/ChangeLog
> +++ b/libelf/ChangeLog
> @@ -1,3 +1,8 @@
> +2019-01-18  Mark Wielaard  <mark@klomp.org>
> +
> +	* Makefile.am (INSTALL_ELFH): Add elf.h to include_HEADERS when
> +	defined, otherwise (the default) add elf.h to noinst_HEADERS.
> +
>  2019-01-16  Mark Wielaard  <mark@klomp.org>
>  
>  	* note_xlate.h (elf_cvt_note): Check n_namesz and n_descsz don't
> diff --git a/libelf/Makefile.am b/libelf/Makefile.am
> index ddaeaa2..d5d63f7 100644
> --- a/libelf/Makefile.am
> +++ b/libelf/Makefile.am
> @@ -39,6 +39,16 @@ noinst_LIBRARIES = libelf_pic.a
>  noinst_PROGRAMS = $(noinst_LIBRARIES:_pic.a=.so)
>  include_HEADERS = libelf.h gelf.h nlist.h
>  
> +noinst_HEADERS = abstract.h common.h exttypes.h gelf_xlate.h libelfP.h \
> +		 version_xlate.h gnuhash_xlate.h note_xlate.h dl-hash.h \
> +		 chdr_xlate.h
> +
> +if INSTALL_ELFH
> +include_HEADERS += elf.h
> +else
> +noinst_HEADERS += elf.h
> +endif
> +
>  pkginclude_HEADERS = elf-knowledge.h
>  
>  libelf_a_SOURCES = elf_version.c elf_hash.c elf_error.c elf_fill.c \
> @@ -123,9 +133,6 @@ uninstall: uninstall-am
>  	rm -f $(DESTDIR)$(libdir)/libelf.so.$(VERSION)
>  	rm -f $(DESTDIR)$(libdir)/libelf.so
>  
> -noinst_HEADERS = elf.h abstract.h common.h exttypes.h gelf_xlate.h libelfP.h \
> -		 version_xlate.h gnuhash_xlate.h note_xlate.h dl-hash.h \
> -		 chdr_xlate.h
>  EXTRA_DIST = libelf.map
>  
>  CLEANFILES += $(am_libelf_pic_a_OBJECTS) libelf.so.$(VERSION)
> diff --git a/tests/ChangeLog b/tests/ChangeLog
> index 8c9e780..1a7bc81 100644
> --- a/tests/ChangeLog
> +++ b/tests/ChangeLog
> @@ -1,3 +1,8 @@
> +2019-01-24  Mark Wielaard  <mark@klomp.org>
> +
> +	* Makefile.am (system_elf_libelf_test_CPPFLAGS): Guard by
> +	!INSTALL_ELFH.
> +
>  2019-01-09  Ulf Hermann <ulf.hermann@qt.io>
>  
>  	* run-readelf-compressed.sh: Skip if USE_BZIP2 not found.
> diff --git a/tests/Makefile.am b/tests/Makefile.am
> index bc8c19a..4c4af78 100644
> --- a/tests/Makefile.am
> +++ b/tests/Makefile.am
> @@ -595,8 +595,10 @@ elfcopy_LDADD = $(libelf)
>  addsections_LDADD = $(libelf)
>  
>  # We want to test the libelf header against the system elf.h header.
> -# Don't include any -I CPPFLAGS.
> +# Don't include any -I CPPFLAGS. Except when we install our own elf.h.
> +if !INSTALL_ELFH
>  system_elf_libelf_test_CPPFLAGS =
> +endif
>  system_elf_libelf_test_LDADD = $(libelf)
>  
>  # A lock file used to make sure only one test dumps core at a time
> -- 
> 1.8.3.1
>