Fix case where IR file provides symbol visibility but replacement file does not.

In PR 22868, two IR files provide conflicting visibility for a symbol.
When a def with PROTECTED visibility is seen after a def with DEFAULT
visibility, gold does not override the visibility. Later, if the
replacement object define the symbol with DEFAULT visibility, the symbol
remains DEFAULT. This was caused by a recent change to allow multiply-defined
absolute symbols, combined with the fact that the plugin framework was using
SHN_ABS as the section index for placeholder symbols. The solution is to
use a real (but arbitrary) section index.

gold/
	PR gold/22868
	* plugin.cc (Sized_pluginobj::do_add_symbols): Use a real section
	index instead of SHN_ABS for defined symbols.
	* testsuite/Makefile.am (plugin_pr22868): New test case.
	* testsuite/Makefile.in: Regenerate
	* testsuite/plugin_pr22868.sh: New test script.
	* testsuite/plugin_pr22868_a.c: New source file.
	* testsuite/plugin_pr22868_b.c: New source file.

1 files changed, 25 insertions, 3 deletions

diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in
index 6f61eae..2f52741 100644
--- a/gold/testsuite/Makefile.in
+++ b/gold/testsuite/Makefile.in
@@ -603,16 +603,19 @@ check_PROGRAMS = $(am__EXEEXT_1) $(am__EXEEXT_2) $(am__EXEEXT_3) \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@am__append_52 = unused.c \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_final_layout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_layout_new_file \
-@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_layout_with_alignment
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_layout_with_alignment \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_pr22868.stdout
 @GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@am__append_53 = plugin_final_layout.sh \
-@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_layout_with_alignment.sh
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_layout_with_alignment.sh \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_pr22868.sh
 
 # Uses the plugin_final_layout.sh script above to avoid duplication
 @GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@am__append_54 = plugin_final_layout.stdout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_final_layout_readelf.stdout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_layout_new_file.stdout \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_layout_new_file_readelf.stdout \
-@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_layout_with_alignment.stdout
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_layout_with_alignment.stdout \
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	plugin_pr22868.stdout
 @GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_55 = exclude_libs_test \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	local_labels_test \
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	discard_locals_test
@@ -5353,6 +5356,8 @@ plugin_final_layout.sh.log: plugin_final_layout.sh
 	@p='plugin_final_layout.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
 plugin_layout_with_alignment.sh.log: plugin_layout_with_alignment.sh
 	@p='plugin_layout_with_alignment.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
+plugin_pr22868.sh.log: plugin_pr22868.sh
+	@p='plugin_pr22868.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
 exclude_libs_test.sh.log: exclude_libs_test.sh
 	@p='exclude_libs_test.sh'; $(am__check_pre) $(LOG_COMPILE) "$$tst" $(am__check_post)
 discard_locals_test.sh.log: discard_locals_test.sh
@@ -7168,6 +7173,23 @@ uninstall-am:
 @GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	$(CXXLINK) -Bgcctestdir/ -shared plugin_section_alignment.o
 @GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_section_alignment.o: plugin_section_alignment.cc
 @GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	$(CXXCOMPILE) -O0 -c -fpic -o $@ $<
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_pr22868.stdout: plugin_pr22868.so
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	$(TEST_READELF) -W --dyn-syms $< >$@ 2>/dev/null
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_pr22868.so: plugin_pr22868_a.o.syms plugin_pr22868_b.o.syms plugin_pr22868_b.o plugin_test.so gcctestdir/ld
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	$(LINK) -Bgcctestdir/ -shared -Wl,--plugin,"./plugin_test.so" plugin_pr22868_a.o.syms plugin_pr22868_b.o.syms
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_pr22868_a.o.syms: plugin_pr22868_a.o
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	$(TEST_READELF) -sW $< >$@ 2>/dev/null
+# Generate the .syms file from an alternate version of the original source
+# file, with a "protected" visibility attribute. We'll link with a
+# "replacement" object that does not have that attribute.
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_pr22868_b.o.syms: plugin_pr22868_b_ir.o
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	$(TEST_READELF) -sW $< >$@ 2>/dev/null
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_pr22868_a.o: plugin_pr22868_a.c
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	$(COMPILE) -c -fpic -o $@ $<
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_pr22868_b_ir.o: plugin_pr22868_b.c
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	$(COMPILE) -c -DIR -fpic -o $@ $<
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_pr22868_b.o: plugin_pr22868_b.c
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@	$(COMPILE) -c -fpic -o $@ $<
 @GCC_TRUE@@NATIVE_LINKER_TRUE@exclude_libs_test.syms: exclude_libs_test
 @GCC_TRUE@@NATIVE_LINKER_TRUE@	$(TEST_READELF) -sW $< >$@ 2>/dev/null
 @GCC_TRUE@@NATIVE_LINKER_TRUE@libexclude_libs_test_1.a: exclude_libs_test_1.o