[PATCH] Supply --build-id=none to ld if building modules

[Pavel Roskin]

This doesn't make any difference to the compiled files, but suppresses
linker warnings on systems where build ID is enabled by default, such as
Fedora 9.

ChangeLog:

        * Makefile.in (MODULE_LDFLAGS): New variable.
        * aclocal.m4 (grub_PROG_LD_BUILD_ID_NONE): New macro.  Check if
        the linker accepts --build-id=none.
        * configure.ac: Call grub_PROG_LD_BUILD_ID_NONE.  Substitute
        MODULE_LDFLAGS.
        * genmk.rb: Use MODULE_LDFLAGS when linking modules.
---

 Makefile.in  |    1 +
 aclocal.m4   |   20 ++++++++++++++++++++
 configure.ac |    2 ++
 genmk.rb     |    2 +-
 4 files changed, 24 insertions(+), 1 deletions(-)

diff --git a/Makefile.in b/Makefile.in
index c29c5fd..c255203 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -68,6 +68,7 @@ TARGET_CFLAGS = @TARGET_CFLAGS@
 TARGET_CPPFLAGS = @TARGET_CPPFLAGS@ -I. -Iinclude -I$(srcdir)/include \
        -Wall -W
 TARGET_LDFLAGS = @TARGET_LDFLAGS@
+MODULE_LDFLAGS = @MODULE_LDFLAGS@
 OBJCOPY = @OBJCOPY@
 STRIP = @STRIP@
 NM = @NM@
diff --git a/aclocal.m4 b/aclocal.m4
index fc67066..a673263 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -81,6 +81,26 @@ fi
 ])
 
 
+dnl Supply --build-id=none to ld if building modules.
+dnl This suppresses warnings from ld on some systems
+AC_DEFUN(grub_PROG_LD_BUILD_ID_NONE,
+[AC_MSG_CHECKING([whether linker accepts --build-id=none])
+AC_CACHE_VAL(grub_cv_prog_ld_build_id_none,
+[save_LDFLAGS="$LDFLAGS"
+LDFLAGS="$LDFLAGS -Wl,--build-id=none"
+AC_TRY_LINK([], [],
+   grub_cv_prog_ld_build_id_none=yes,
+   grub_cv_prog_ld_build_id_none=no)
+LDFLAGS="$save_LDFLAGS"
+])
+AC_MSG_RESULT([$grub_cv_prog_ld_build_id_none])
+
+if test "x$grub_cv_prog_ld_build_id_none" = xyes; then
+  MODULE_LDFLAGS="$MODULE_LDFLAGS -Wl,--build-id=none"
+fi
+])
+
+
 dnl Mass confusion!
 dnl Older versions of GAS interpret `.code16' to mean ``generate 32-bit
 dnl instructions, but implicitly insert addr32 and data32 bytes so
diff --git a/configure.ac b/configure.ac
index 5ec7a47..18049db 100644
--- a/configure.ac
+++ b/configure.ac
@@ -253,6 +253,7 @@ fi
 AC_SUBST(TARGET_CFLAGS)
 AC_SUBST(TARGET_CPPFLAGS)
 AC_SUBST(TARGET_LDFLAGS)
+AC_SUBST(MODULE_LDFLAGS)
 
 # Set them to their new values for the tests below.
 CC="$TARGET_CC"
@@ -262,6 +263,7 @@ LDFLAGS="$TARGET_LDFLAGS"
 
 # Defined in aclocal.m4.
 grub_PROG_OBJCOPY_ABSOLUTE
+grub_PROG_LD_BUILD_ID_NONE
 grub_ASM_USCORE
 if test "x$target_cpu" = xi386; then
   grub_CHECK_START_SYMBOL
diff --git a/genmk.rb b/genmk.rb
index a2179fa..56dee5c 100644
--- a/genmk.rb
+++ b/genmk.rb
@@ -114,7 +114,7 @@ UNDSYMFILES += #{undsym}
 
 address@hidden: #{pre_obj} #{mod_obj}
        -rm -f $@
-       $(TARGET_CC) $(#{prefix}_LDFLAGS) $(TARGET_LDFLAGS) -Wl,-r,-d -o $@ $^
+       $(TARGET_CC) $(#{prefix}_LDFLAGS) $(TARGET_LDFLAGS) $(MODULE_LDFLAGS) 
-Wl,-r,-d -o $@ $^
        $(STRIP) --strip-unneeded -K grub_mod_init -K grub_mod_fini -R .note -R 
.comment $@
 
 #{pre_obj}: $(#{prefix}_DEPENDENCIES) #{objs_str}