[PATCH] PR other/91396 Fix static link error with -fvtable-verify

["Caroline Tice via gcc-patches" <gcc-patches at gcc dot gnu dot org>]

Hi,

This patch is to fix a bug where linking with -fvtable-verify  and
-static causes the linker to complain about multiple definitions of
things in the vtv_end*.o files (once from the .o file and once from
libvtv.a).   (See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91396).
The fix is for the GNU_USER_TARGET_ENDFILE_SPEC to only include the
vtv_end*.o files if we're not doing static linking (and we are using
-fvtable-verify flags).

Tested this fix by verifying that the test case in the bug compiles
both with and without -static, and that there were no new regressions
in the libvtv testsuite.  I'm in the process of doing a full bootstrap
build with this change.   Assuming the bootstrap passes, is this ok to
commit?

Index: gcc/config/gnu-user.h
===================================================================
--- gcc/config/gnu-user.h (revision 274317)
+++ gcc/config/gnu-user.h (working copy)
@@ -73,9 +73,9 @@
    GNU userspace "finalizer" file, `crtn.o'.  */

 #define GNU_USER_TARGET_ENDFILE_SPEC \
-  "%{fvtable-verify=none:%s; \
+  "%{!static:%{fvtable-verify=none:%s; \
      fvtable-verify=preinit:vtv_end_preinit.o%s; \
-     fvtable-verify=std:vtv_end.o%s} \
+     fvtable-verify=std:vtv_end.o%s}} \
    %{static:crtend.o%s; \
      shared|static-pie|" PIE_SPEC ":crtendS.o%s; \
      :crtend.o%s} " \

ChangeLog entry:

2019-08-12  Caroline Tice  <cmtice@google.com>

        PR other/91396
        * config/gnu-user.h (GNU_USER_TARGET_ENDFILE_SPEC): Only add the
        vtv_end.o or vtv_end_preinit.o files if !static.