gold: Treat symbols with version index 0 as unversioned

Oracle Solaris 11.4 Linker and Libraries Guide:

https://docs.oracle.com/en/operating-systems/solaris/oracle-solaris/11.4/linkers-libraries/version-symbol-section.html

defines VER_NDX_LOCAL to 0 with a comment, "Symbol has local scope".  This
leads to different interpretations by different linker implementations.
However Solaris as well as ld and ld.so in glibc always treat symbols
with version index 0 as unversioned symbols with global binding.  As
discussed in

https://sourceware.org/bugzilla/show_bug.cgi?id=33577

in hindsight, VER_NDX_NONE might be a better name.  Ali from Oracle is
working on clarifying what version index 0 really means for unversioned
symbols with global binding.  In the meantime, update gold to treat
symbols with version index 0 as unversioned with global binding.

elfcpp/

	PR gold/33577
	* elfcpp.h (VER_NDX_LOCAL): Update comments.
	(VER_NDX_GLOBAL): Likewise.

gold/

	PR gold/33577
	* dynobj.cc (Versions::symbol_section_contents): Set unversioned
	symbol version index to VER_NDX_LOCAL.
	* symtab.cc (Symbol_table::add_from_dynobj): Don't check
	VER_NDX_LOCAL.
	* testsuite/Makefile.am (check_SCRIPTS): Add ver_test_pr33577.sh.
	(check_DATA): Add ver_test_pr33577a.syms and
	ver_test_pr33577b.syms.
	(ver_test_pr33577a.syms): New rule.
	(ver_test_pr33577.so): Likewise.
	(ver_test_pr33577b.syms): Likewise.
	(ver_test_pr33577): Likewise.
	* testsuite/Makefile.in: Regenerated.
	* testsuite/ver_matching_test.sh: Updated to checking missing
	Base version.
	* testsuite/ver_test_14.sh (check_missing): New.
	Updated to check missing Base version.
	* testsuite/ver_test_pr33577.sh: New fille.
	* testsuite/ver_test_pr33577a.c: Likewise.
	* testsuite/ver_test_pr33577b.c: Likewise.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>

diff --git a/elfcpp/elfcpp.h b/elfcpp/elfcpp.h
index 3ceddbda19c17c3ef13448aa365a1f01ef1a1bd1..a363294506f069b5c77c3c0b0b7a79bb723d7eca 100644 (file)
--- a/elfcpp/elfcpp.h
+++ b/elfcpp/elfcpp.h
@@ -951,7 +951,9 @@ const int VER_FLG_INFO = 0x4;
 
 // Special constants found in the SHT_GNU_versym entries.
 
+// Symbol is a local symbol or an unversioned symbol with global binding.
 const int VER_NDX_LOCAL = 0;
+// Symbol is a base symbol with global binding.
 const int VER_NDX_GLOBAL = 1;
 
 // A SHT_GNU_versym section holds 16-bit words.  This bit is set if

diff --git a/gold/dynobj.cc b/gold/dynobj.cc
index d6b06e80976cbac93ffd52d56f2610399ff2a1bd..380b2e297cb735d31193ee383beacda2dd12e6c6 100644 (file)
--- a/gold/dynobj.cc
+++ b/gold/dynobj.cc
@@ -1756,12 +1756,7 @@ Versions::symbol_section_contents(const Symbol_table* symtab,
       unsigned int version_index;
       const char* version = (*p)->version();
       if (version == NULL)
-       {
-         if ((*p)->is_defined() && !(*p)->is_from_dynobj())
-           version_index = elfcpp::VER_NDX_GLOBAL;
-         else
-           version_index = elfcpp::VER_NDX_LOCAL;
-       }
+       version_index = elfcpp::VER_NDX_LOCAL;
       else if (version[0] == '\0')
         version_index = elfcpp::VER_NDX_GLOBAL;
       else

diff --git a/gold/symtab.cc b/gold/symtab.cc
index 6615a44f26b25b75c8fd37fead5d246cdb92fd62..877ddd7547c48034aee53900e3c187be238fc580 100644 (file)
--- a/gold/symtab.cc
+++ b/gold/symtab.cc
@@ -1632,24 +1632,15 @@ Symbol_table::add_from_dynobj(
          bool hidden = (v & elfcpp::VERSYM_HIDDEN) != 0;
          v &= elfcpp::VERSYM_VERSION;
 
-         // The Sun documentation says that V can be VER_NDX_LOCAL,
-         // or VER_NDX_GLOBAL, or a version index.  The meaning of
-         // VER_NDX_LOCAL is defined as "Symbol has local scope."
-         // The old GNU linker will happily generate VER_NDX_LOCAL
-         // for an undefined symbol.  I don't know what the Sun
-         // linker will generate.
-
-         if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
-             && st_shndx != elfcpp::SHN_UNDEF)
-           {
-             // This symbol should not be visible outside the object.
-             continue;
-           }
-
          // At this point we are definitely going to add this symbol.
          Stringpool::Key name_key;
          name = this->namepool_.add(name, true, &name_key);
 
+         // The Sun documentation says that V can be VER_NDX_LOCAL,
+         // or VER_NDX_GLOBAL, or a version index.  The meaning of
+         // VER_NDX_LOCAL means that symbol is a local dynamic symbol
+         // or an unversioned global/weak symbol which is defined or
+         // undefined.
          if (v == static_cast<unsigned int>(elfcpp::VER_NDX_LOCAL)
              || v == static_cast<unsigned int>(elfcpp::VER_NDX_GLOBAL))
            {

diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am
index 8f158ba20ccd1dbdb89e7861af60395f1f1f9d90..71ef3e32a3428d0ab0b13589c286b471960826df 100644 (file)
--- a/gold/testsuite/Makefile.am
+++ b/gold/testsuite/Makefile.am
@@ -2002,6 +2002,17 @@ ver_test_pr31830_lto_b.syms: ver_test_pr31830_lto_b.so
 ver_test_pr31830_lto_b.so: gcctestdir/ld $(srcdir)/ver_test_pr31830_lto.c $(srcdir)/ver_test_pr31830.script
        $(LINK) -Bgcctestdir/ -shared -o $@ -O2 -fPIC -flto-partition=max -flto=2 $(srcdir)/ver_test_pr31830_lto.c -Wl,--version-script,$(srcdir)/ver_test_pr31830.script
 
+check_SCRIPTS += ver_test_pr33577.sh
+check_DATA += ver_test_pr33577a.syms ver_test_pr33577b.syms
+ver_test_pr33577a.syms: ver_test_pr33577.so
+       $(TEST_READELF) --dyn-syms -W $< >$@
+ver_test_pr33577.so: gcctestdir/ld $(srcdir)/ver_test_pr33577a.c
+       $(LINK) -Bgcctestdir/ -shared -o $@ -O2 -fPIC $(srcdir)/ver_test_pr33577a.c
+ver_test_pr33577b.syms: ver_test_pr33577
+       $(TEST_READELF) --dyn-syms -W $< >$@
+ver_test_pr33577: gcctestdir/ld $(srcdir)/ver_test_pr33577b.c ver_test_pr33577.so
+       $(LINK) -Bgcctestdir/ -o $@ -O2 $(srcdir)/ver_test_pr33577b.c ver_test_pr33577.so
+
 check_SCRIPTS += weak_as_needed.sh
 check_DATA += weak_as_needed.stdout
 weak_as_needed.stdout: weak_as_needed_a.so

diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in
index 357dec0d4f9adcc23a50c6517978c520ca1bcb08..bdfc7770855e60f3237c8ecdea05abcab70e8c6c 100644 (file)
--- a/gold/testsuite/Makefile.in
+++ b/gold/testsuite/Makefile.in
@@ -475,6 +475,7 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_test_pr23409.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_test_pr31830.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_test_pr31830_lto.sh \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_test_pr33577.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ weak_as_needed.sh relro_test.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_matching_test.sh \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ script_test_3.sh \
@@ -536,6 +537,8 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_test_pr31830_b.syms \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_test_pr31830_lto_a.syms \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_test_pr31830_lto_b.syms \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_test_pr33577a.syms \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ ver_test_pr33577b.syms \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ weak_as_needed.stdout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ protected_3.err \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ relro_test.stdout \
@@ -5929,6 +5932,13 @@ ver_test_pr31830_lto.sh.log: ver_test_pr31830_lto.sh
        --log-file $$b.log --trs-file $$b.trs \
        $(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
        "$$tst" $(AM_TESTS_FD_REDIRECT)
+ver_test_pr33577.sh.log: ver_test_pr33577.sh
+       @p='ver_test_pr33577.sh'; \
+       b='ver_test_pr33577.sh'; \
+       $(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
+       --log-file $$b.log --trs-file $$b.trs \
+       $(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
+       "$$tst" $(AM_TESTS_FD_REDIRECT)
 weak_as_needed.sh.log: weak_as_needed.sh
        @p='weak_as_needed.sh'; \
        b='weak_as_needed.sh'; \
@@ -8963,6 +8973,14 @@ uninstall-am:
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_READELF) --dyn-syms -W $< >$@
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ver_test_pr31830_lto_b.so: gcctestdir/ld $(srcdir)/ver_test_pr31830_lto.c $(srcdir)/ver_test_pr31830.script
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ $(LINK) -Bgcctestdir/ -shared -o $@ -O2 -fPIC -flto-partition=max -flto=2 $(srcdir)/ver_test_pr31830_lto.c -Wl,--version-script,$(srcdir)/ver_test_pr31830.script
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ver_test_pr33577a.syms: ver_test_pr33577.so
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_READELF) --dyn-syms -W $< >$@
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ver_test_pr33577.so: gcctestdir/ld $(srcdir)/ver_test_pr33577a.c
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(LINK) -Bgcctestdir/ -shared -o $@ -O2 -fPIC $(srcdir)/ver_test_pr33577a.c
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ver_test_pr33577b.syms: ver_test_pr33577
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_READELF) --dyn-syms -W $< >$@
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ver_test_pr33577: gcctestdir/ld $(srcdir)/ver_test_pr33577b.c ver_test_pr33577.so
+@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(LINK) -Bgcctestdir/ -o $@ -O2 $(srcdir)/ver_test_pr33577b.c ver_test_pr33577.so
 @GCC_TRUE@@NATIVE_LINKER_TRUE@weak_as_needed.stdout: weak_as_needed_a.so
 @GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_READELF) -dW --dyn-syms $< >$@
 @GCC_TRUE@@NATIVE_LINKER_TRUE@weak_as_needed_a.so: gcctestdir/ld weak_as_needed_a.o weak_as_needed_b.so weak_as_needed_c.so

diff --git a/gold/testsuite/ver_matching_test.sh b/gold/testsuite/ver_matching_test.sh
index 3c34086fd823c71557be4045f34adab0d6ab94e5..9abdfbdc96c485d7b9d6339f517dcaf49a3877e7 100755 (executable)
--- a/gold/testsuite/ver_matching_test.sh
+++ b/gold/testsuite/ver_matching_test.sh
@@ -54,22 +54,22 @@ check_missing()
 }
 
 check ver_matching_test.stdout "V1  *sizeof_headers$"
-check ver_matching_test.stdout "Base  *globaoeufostuff$"
+check ver_matching_test.stdout "globaoeufostuff$"
 check ver_matching_test.stdout "V1  *globaoeufxstuff$"
 check ver_matching_test.stdout "V2  *otherns::stuff$"
-check ver_matching_test.stdout "Base  *otherns::biz$"
+check ver_matching_test.stdout "otherns::biz$"
 check ver_matching_test.stdout "V1  *foo$"
 check ver_matching_test.stdout "V1  *bar()$"
-check ver_matching_test.stdout "Base  *bar1()$"
+check ver_matching_test.stdout "bar1()$"
 check ver_matching_test.stdout "V1  *bar2$"
 check ver_matching_test.stdout "V1  *myns::blah()$"
 check ver_matching_test.stdout "V1  *myns::bip()$"
 check ver_matching_test.stdout "V1  *myns::Stuff::Stuff()$"
-check ver_matching_test.stdout "Base  *Biz::Biz()$"
+check ver_matching_test.stdout "Biz::Biz()$"
 check ver_matching_test.stdout "V2  *blaza1$"
 check ver_matching_test.stdout "V2  *blaza2$"
 check ver_matching_test.stdout "V2  *blaza$"
-check ver_matching_test.stdout "Base  *bla$"
+check ver_matching_test.stdout "bla$"
 check ver_matching_test.stdout "V2  *blaz$"
 check ver_matching_test.stdout "V2  *blazb$"
 
@@ -79,6 +79,12 @@ check ver_matching_test.stdout "V1   *baz(int\\*)$"
 check_missing ver_matching_test.stdout "V1   *baz(int\\*, char)$"
 check_missing ver_matching_test.stdout "V1   *baz(char\\*, int)$"
 
+check_missing ver_matching_test.stdout "Base  *globaoeufostuff$"
+check_missing ver_matching_test.stdout "Base  *otherns::biz$"
+check_missing ver_matching_test.stdout "Base  *bar1()$"
+check_missing ver_matching_test.stdout "Base  *Biz::Biz()$"
+check_missing ver_matching_test.stdout "Base  *bla$"
+
 check_missing ver_matching_test.stdout "foo1"
 
 # This symbols is injected by the linker itself, but should still

diff --git a/gold/testsuite/ver_test_14.sh b/gold/testsuite/ver_test_14.sh
index 362507d65481c12967c7e9efad795b4a542f8ad8..7c1f0d4c16cac242f047ae5983ff1b9c0d1a3e14 100755 (executable)
--- a/gold/testsuite/ver_test_14.sh
+++ b/gold/testsuite/ver_test_14.sh
@@ -35,9 +35,23 @@ check()
     fi
 }
 
+check_missing()
+{
+    if grep -q "$2" "$1"
+    then
+       echo "Found unexpected symbol in $1:"
+       echo "   $2"
+       echo ""
+       echo "Actual output below:"
+       cat "$1"
+       exit 1
+    fi
+}
+
 check ver_test_14.syms "V1 *\(0x[0-9a-f][048c]\)\? t2()$"
 check ver_test_14.syms "V1 *\(0x[0-9a-f][048c]\)\? t3()$"
 check ver_test_14.syms "V1 *\(0x[0-9a-f][048c]\)\? t4()$"
-check ver_test_14.syms "Base *\(0x[0-9a-f][048c]\)\? t4_2a$"
+check ver_test_14.syms "t4_2a$"
+check_missing ver_test_14.syms "Base *\(0x[0-9a-f][048c]\)\? t4_2a$"
 
 exit 0

diff --git a/gold/testsuite/ver_test_pr33577.sh b/gold/testsuite/ver_test_pr33577.sh
new file mode 100755 (executable)
index 0000000..b2dd6de
--- /dev/null
+++ b/gold/testsuite/ver_test_pr33577.sh
@@ -0,0 +1,47 @@
+#!/bin/sh
+
+# ver_test_pr33577.sh -- a test case for unversioned symbols.
+
+# Copyright (C) 2025 Free Software Foundation, Inc.
+
+# This file is part of gold.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+# MA 02110-1301, USA.
+
+# This test verifies that linker-generated symbols (e.g., _end)
+# get correct version information even in the presence of
+# a shared library that provides those symbols with different
+# versions.
+
+check()
+{
+    if ! grep -q "$2" "$1"
+    then
+       echo "Did not find expected symbol in $1:"
+       echo "   $2"
+       echo ""
+       echo "Actual output below:"
+       cat "$1"
+       exit 1
+    fi
+}
+
+check ver_test_pr33577a.syms "bar$"
+check ver_test_pr33577a.syms "foo$"
+check ver_test_pr33577b.syms "bar$"
+check ver_test_pr33577b.syms "foo$"
+
+exit 0

diff --git a/gold/testsuite/ver_test_pr33577a.c b/gold/testsuite/ver_test_pr33577a.c
new file mode 100644 (file)
index 0000000..34655ba
--- /dev/null
+++ b/gold/testsuite/ver_test_pr33577a.c
@@ -0,0 +1,11 @@
+#include <stdio.h>
+
+extern void foo (void);
+extern void bar (void);
+
+void
+foo (void)
+{
+  bar ();
+  printf ("base\n");
+}

diff --git a/gold/testsuite/ver_test_pr33577b.c b/gold/testsuite/ver_test_pr33577b.c
new file mode 100644 (file)
index 0000000..821d53c
--- /dev/null
+++ b/gold/testsuite/ver_test_pr33577b.c
@@ -0,0 +1,17 @@
+#include <stdio.h>
+
+extern void foo (void);
+extern void bar (void);
+
+void
+bar (void)
+{
+  printf ("bar\n");
+}
+
+int
+main ()
+{
+  foo ();
+  return 0;
+}