From a100d66fb42044153dc0e93c96d7944dab0cc674 Mon Sep 17 00:00:00 2001 From: Sriraman Tallam Date: Thu, 23 Apr 2015 13:56:40 -0700 Subject: [PATCH] Add option --weak-unresolved-symbols to treat unresolved symbols as weak ref. This patch adds option --weak-unresolved-symbols to treat unresolved symbols as weak references. This is helpful when we want the link to succeed with unresolved symbols and the dynamic loader to not complain at run-time. Option --warn-unresolved-symbols lets the link succeed but could fail at run-time with unresolved symbol warnings especially when the unresolved symbols have GOT entries and dynamic relocations against them, like when -fPIE is used. --- gold/ChangeLog | 10 +++++++++ gold/options.h | 3 +++ gold/symtab.cc | 7 +++++++ gold/symtab.h | 6 ++++-- gold/testsuite/Makefile.am | 5 +++++ gold/testsuite/Makefile.in | 43 +++++++++++++++++++++++++++++++++++--- 6 files changed, 69 insertions(+), 5 deletions(-) diff --git a/gold/ChangeLog b/gold/ChangeLog index e736d331043..c5b30933b4a 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,13 @@ +2015-04-23 Sriraman Tallam + * options.h (--weak-unresolved-symbols): New option. + * symtab.cc (Symbol_table::sized_write_globals): Change symbol + binding to weak with new option. + * symtab.h (is_weak_undefined): Check for new option. + (is_strong_undefined): Check for new option. + * testsuite/Makefile.am (weak_unresolved_symbols_test): New test. + * testsuite/Makefile.in: Regenerate. + * testsuite/weak_unresolved_symbols_test.cc: New file. + 2015-04-20 Ian Coolidge * symtab.cc (Symbol::should_add_dynsym_entry): Return true for diff --git a/gold/options.h b/gold/options.h index c1a5743ebaf..bb3bee6b10a 100644 --- a/gold/options.h +++ b/gold/options.h @@ -1219,6 +1219,9 @@ class General_options options::TWO_DASHES, '\0', N_("Report unresolved symbols as errors"), NULL, true); + DEFINE_bool(weak_unresolved_symbols, options::TWO_DASHES, '\0', false, + N_("Convert unresolved symbols to weak references"), + NULL); DEFINE_bool(wchar_size_warning, options::TWO_DASHES, '\0', true, NULL, N_("(ARM only) Do not warn about objects with incompatible " diff --git a/gold/symtab.cc b/gold/symtab.cc index c1972210d67..d2ed3520da0 100644 --- a/gold/symtab.cc +++ b/gold/symtab.cc @@ -2920,6 +2920,13 @@ Symbol_table::sized_write_globals(const Stringpool* sympool, typename elfcpp::Elf_types::Elf_Addr dynsym_value = sym_value; elfcpp::STB binding = sym->binding(); + // If --weak-unresolved-symbols is set, change binding of unresolved + // global symbols to STB_WEAK. + if (parameters->options().weak_unresolved_symbols() + && binding == elfcpp::STB_GLOBAL + && sym->is_undefined()) + binding = elfcpp::STB_WEAK; + // If --no-gnu-unique is set, change STB_GNU_UNIQUE to STB_GLOBAL. if (binding == elfcpp::STB_GNU_UNIQUE && !parameters->options().gnu_unique()) diff --git a/gold/symtab.h b/gold/symtab.h index 9413360fc23..6f47c5e1b19 100644 --- a/gold/symtab.h +++ b/gold/symtab.h @@ -526,7 +526,8 @@ class Symbol { return (this->is_undefined() && (this->binding() == elfcpp::STB_WEAK - || this->is_undef_binding_weak())); + || this->is_undef_binding_weak() + || parameters->options().weak_unresolved_symbols())); } // Return whether this is a strong undefined symbol. @@ -535,7 +536,8 @@ class Symbol { return (this->is_undefined() && this->binding() != elfcpp::STB_WEAK - && !this->is_undef_binding_weak()); + && !this->is_undef_binding_weak() + && !parameters->options().weak_unresolved_symbols()); } // Return whether this is an absolute symbol. diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am index c57b2b3ef29..e47174dca2f 100644 --- a/gold/testsuite/Makefile.am +++ b/gold/testsuite/Makefile.am @@ -533,6 +533,11 @@ pie_copyrelocs_shared_test.o: pie_copyrelocs_shared_test.cc pie_copyrelocs_shared_test.so: pie_copyrelocs_shared_test.o gcctestdir/ld $(CXXLINK) -Bgcctestdir/ -shared pie_copyrelocs_shared_test.o +check_PROGRAMS += weak_unresolved_symbols_test +weak_unresolved_symbols_test_SOURCES = weak_unresolved_symbols_test.cc +weak_unresolved_symbols_test_CXXFLAGS = -fPIE +weak_unresolved_symbols_test_LDFLAGS = -Bgcctestdir/ -pie -Wl,--weak-unresolved-symbols + check_SCRIPTS += two_file_shared.sh check_DATA += two_file_shared.dbg MOSTLYCLEANFILES += two_file_shared.dbg diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in index 90c305463d0..4d7a54f51f5 100644 --- a/gold/testsuite/Makefile.in +++ b/gold/testsuite/Makefile.in @@ -147,7 +147,8 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ two_file_separate_shared_21_test \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ two_file_relocatable_test \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ two_file_pie_test \ -@GCC_TRUE@@NATIVE_LINKER_TRUE@ pie_copyrelocs_test +@GCC_TRUE@@NATIVE_LINKER_TRUE@ pie_copyrelocs_test \ +@GCC_TRUE@@NATIVE_LINKER_TRUE@ weak_unresolved_symbols_test # The nonpic tests will fail on platforms which can not put non-PIC # code into shared libraries, so we just don't run them in that case. @@ -842,7 +843,8 @@ libgoldtest_a_OBJECTS = $(am_libgoldtest_a_OBJECTS) @GCC_TRUE@@NATIVE_LINKER_TRUE@ two_file_separate_shared_21_test$(EXEEXT) \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ two_file_relocatable_test$(EXEEXT) \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ two_file_pie_test$(EXEEXT) \ -@GCC_TRUE@@NATIVE_LINKER_TRUE@ pie_copyrelocs_test$(EXEEXT) +@GCC_TRUE@@NATIVE_LINKER_TRUE@ pie_copyrelocs_test$(EXEEXT) \ +@GCC_TRUE@@NATIVE_LINKER_TRUE@ weak_unresolved_symbols_test$(EXEEXT) @FN_PTRS_IN_SO_WITHOUT_PIC_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@am__EXEEXT_9 = two_file_shared_1_nonpic_test$(EXEEXT) \ @FN_PTRS_IN_SO_WITHOUT_PIC_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ two_file_shared_2_nonpic_test$(EXEEXT) \ @FN_PTRS_IN_SO_WITHOUT_PIC_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ two_file_same_shared_nonpic_test$(EXEEXT) \ @@ -1966,6 +1968,17 @@ weak_undef_test_LINK = $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) \ weak_undef_test_2_OBJECTS = $(am_weak_undef_test_2_OBJECTS) weak_undef_test_2_LINK = $(CXXLD) $(AM_CXXFLAGS) $(CXXFLAGS) \ $(weak_undef_test_2_LDFLAGS) $(LDFLAGS) -o $@ +@GCC_TRUE@@NATIVE_LINKER_TRUE@am_weak_unresolved_symbols_test_OBJECTS = weak_unresolved_symbols_test-weak_unresolved_symbols_test.$(OBJEXT) +weak_unresolved_symbols_test_OBJECTS = \ + $(am_weak_unresolved_symbols_test_OBJECTS) +weak_unresolved_symbols_test_LDADD = $(LDADD) +weak_unresolved_symbols_test_DEPENDENCIES = libgoldtest.a ../libgold.a \ + ../../libiberty/libiberty.a $(am__DEPENDENCIES_1) \ + $(am__DEPENDENCIES_1) $(am__DEPENDENCIES_1) \ + $(am__DEPENDENCIES_1) +weak_unresolved_symbols_test_LINK = $(CXXLD) \ + $(weak_unresolved_symbols_test_CXXFLAGS) $(CXXFLAGS) \ + $(weak_unresolved_symbols_test_LDFLAGS) $(LDFLAGS) -o $@ DEFAULT_INCLUDES = -I.@am__isrc@ -I$(top_builddir) depcomp = $(SHELL) $(top_srcdir)/../depcomp am__depfiles_maybe = depfiles @@ -2057,7 +2070,8 @@ SOURCES = $(libgoldtest_a_SOURCES) basic_pic_test.c basic_pie_test.c \ $(ver_test_8_SOURCES) $(ver_test_9_SOURCES) \ $(weak_alias_test_SOURCES) weak_plt.c $(weak_test_SOURCES) \ $(weak_undef_nonpic_test_SOURCES) $(weak_undef_test_SOURCES) \ - $(weak_undef_test_2_SOURCES) + $(weak_undef_test_2_SOURCES) \ + $(weak_unresolved_symbols_test_SOURCES) ETAGS = etags CTAGS = ctags am__tty_colors = \ @@ -2465,6 +2479,9 @@ LDADD = libgoldtest.a ../libgold.a ../../libiberty/libiberty.a $(LIBINTL) \ @GCC_TRUE@@NATIVE_LINKER_TRUE@pie_copyrelocs_test_CXXFLAGS = -fno-exceptions -fno-asynchronous-unwind-tables @GCC_TRUE@@NATIVE_LINKER_TRUE@pie_copyrelocs_test_LDFLAGS = -Bgcctestdir/ -Wl,-R,. -pie @GCC_TRUE@@NATIVE_LINKER_TRUE@pie_copyrelocs_test_LDADD = pie_copyrelocs_shared_test.so +@GCC_TRUE@@NATIVE_LINKER_TRUE@weak_unresolved_symbols_test_SOURCES = weak_unresolved_symbols_test.cc +@GCC_TRUE@@NATIVE_LINKER_TRUE@weak_unresolved_symbols_test_CXXFLAGS = -fPIE +@GCC_TRUE@@NATIVE_LINKER_TRUE@weak_unresolved_symbols_test_LDFLAGS = -Bgcctestdir/ -pie -Wl,--weak-unresolved-symbols @FN_PTRS_IN_SO_WITHOUT_PIC_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@two_file_shared_1_nonpic_test_SOURCES = \ @FN_PTRS_IN_SO_WITHOUT_PIC_TRUE@@GCC_TRUE@@NATIVE_LINKER_TRUE@ two_file_test_2.cc two_file_test_main.cc @@ -3722,6 +3739,9 @@ weak_undef_test$(EXEEXT): $(weak_undef_test_OBJECTS) $(weak_undef_test_DEPENDENC weak_undef_test_2$(EXEEXT): $(weak_undef_test_2_OBJECTS) $(weak_undef_test_2_DEPENDENCIES) @rm -f weak_undef_test_2$(EXEEXT) $(weak_undef_test_2_LINK) $(weak_undef_test_2_OBJECTS) $(weak_undef_test_2_LDADD) $(LIBS) +weak_unresolved_symbols_test$(EXEEXT): $(weak_unresolved_symbols_test_OBJECTS) $(weak_unresolved_symbols_test_DEPENDENCIES) + @rm -f weak_unresolved_symbols_test$(EXEEXT) + $(weak_unresolved_symbols_test_LINK) $(weak_unresolved_symbols_test_OBJECTS) $(weak_unresolved_symbols_test_LDADD) $(LIBS) mostlyclean-compile: -rm -f *.$(OBJEXT) @@ -3852,6 +3872,7 @@ distclean-compile: @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/weak_test.Po@am__quote@ @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/weak_undef_test.Po@am__quote@ @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/weak_undef_test_2.Po@am__quote@ +@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/weak_unresolved_symbols_test-weak_unresolved_symbols_test.Po@am__quote@ .c.o: @am__fastdepCC_TRUE@ $(COMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ $< @@ -3979,6 +4000,20 @@ pie_copyrelocs_test-pie_copyrelocs_test.obj: pie_copyrelocs_test.cc @AMDEP_TRUE@@am__fastdepCXX_FALSE@ DEPDIR=$(DEPDIR) $(CXXDEPMODE) $(depcomp) @AMDEPBACKSLASH@ @am__fastdepCXX_FALSE@ $(CXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(pie_copyrelocs_test_CXXFLAGS) $(CXXFLAGS) -c -o pie_copyrelocs_test-pie_copyrelocs_test.obj `if test -f 'pie_copyrelocs_test.cc'; then $(CYGPATH_W) 'pie_copyrelocs_test.cc'; else $(CYGPATH_W) '$(srcdir)/pie_copyrelocs_test.cc'; fi` +weak_unresolved_symbols_test-weak_unresolved_symbols_test.o: weak_unresolved_symbols_test.cc +@am__fastdepCXX_TRUE@ $(CXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(weak_unresolved_symbols_test_CXXFLAGS) $(CXXFLAGS) -MT weak_unresolved_symbols_test-weak_unresolved_symbols_test.o -MD -MP -MF $(DEPDIR)/weak_unresolved_symbols_test-weak_unresolved_symbols_test.Tpo -c -o weak_unresolved_symbols_test-weak_unresolved_symbols_test.o `test -f 'weak_unresolved_symbols_test.cc' || echo '$(srcdir)/'`weak_unresolved_symbols_test.cc +@am__fastdepCXX_TRUE@ $(am__mv) $(DEPDIR)/weak_unresolved_symbols_test-weak_unresolved_symbols_test.Tpo $(DEPDIR)/weak_unresolved_symbols_test-weak_unresolved_symbols_test.Po +@AMDEP_TRUE@@am__fastdepCXX_FALSE@ source='weak_unresolved_symbols_test.cc' object='weak_unresolved_symbols_test-weak_unresolved_symbols_test.o' libtool=no @AMDEPBACKSLASH@ +@AMDEP_TRUE@@am__fastdepCXX_FALSE@ DEPDIR=$(DEPDIR) $(CXXDEPMODE) $(depcomp) @AMDEPBACKSLASH@ +@am__fastdepCXX_FALSE@ $(CXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(weak_unresolved_symbols_test_CXXFLAGS) $(CXXFLAGS) -c -o weak_unresolved_symbols_test-weak_unresolved_symbols_test.o `test -f 'weak_unresolved_symbols_test.cc' || echo '$(srcdir)/'`weak_unresolved_symbols_test.cc + +weak_unresolved_symbols_test-weak_unresolved_symbols_test.obj: weak_unresolved_symbols_test.cc +@am__fastdepCXX_TRUE@ $(CXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(weak_unresolved_symbols_test_CXXFLAGS) $(CXXFLAGS) -MT weak_unresolved_symbols_test-weak_unresolved_symbols_test.obj -MD -MP -MF $(DEPDIR)/weak_unresolved_symbols_test-weak_unresolved_symbols_test.Tpo -c -o weak_unresolved_symbols_test-weak_unresolved_symbols_test.obj `if test -f 'weak_unresolved_symbols_test.cc'; then $(CYGPATH_W) 'weak_unresolved_symbols_test.cc'; else $(CYGPATH_W) '$(srcdir)/weak_unresolved_symbols_test.cc'; fi` +@am__fastdepCXX_TRUE@ $(am__mv) $(DEPDIR)/weak_unresolved_symbols_test-weak_unresolved_symbols_test.Tpo $(DEPDIR)/weak_unresolved_symbols_test-weak_unresolved_symbols_test.Po +@AMDEP_TRUE@@am__fastdepCXX_FALSE@ source='weak_unresolved_symbols_test.cc' object='weak_unresolved_symbols_test-weak_unresolved_symbols_test.obj' libtool=no @AMDEPBACKSLASH@ +@AMDEP_TRUE@@am__fastdepCXX_FALSE@ DEPDIR=$(DEPDIR) $(CXXDEPMODE) $(depcomp) @AMDEPBACKSLASH@ +@am__fastdepCXX_FALSE@ $(CXX) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(weak_unresolved_symbols_test_CXXFLAGS) $(CXXFLAGS) -c -o weak_unresolved_symbols_test-weak_unresolved_symbols_test.obj `if test -f 'weak_unresolved_symbols_test.cc'; then $(CYGPATH_W) 'weak_unresolved_symbols_test.cc'; else $(CYGPATH_W) '$(srcdir)/weak_unresolved_symbols_test.cc'; fi` + ID: $(HEADERS) $(SOURCES) $(LISP) $(TAGS_FILES) list='$(SOURCES) $(HEADERS) $(LISP) $(TAGS_FILES)'; \ unique=`for i in $$list; do \ @@ -4403,6 +4438,8 @@ two_file_pie_test.log: two_file_pie_test$(EXEEXT) @p='two_file_pie_test$(EXEEXT)'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post) pie_copyrelocs_test.log: pie_copyrelocs_test$(EXEEXT) @p='pie_copyrelocs_test$(EXEEXT)'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post) +weak_unresolved_symbols_test.log: weak_unresolved_symbols_test$(EXEEXT) + @p='weak_unresolved_symbols_test$(EXEEXT)'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post) two_file_shared_1_nonpic_test.log: two_file_shared_1_nonpic_test$(EXEEXT) @p='two_file_shared_1_nonpic_test$(EXEEXT)'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post) two_file_shared_2_nonpic_test.log: two_file_shared_2_nonpic_test$(EXEEXT) -- 2.30.2