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[gold][patch] Fix plugin API so that add_symbols is not required
- From: Cary Coutant <ccoutant at google dot com>
- To: Binutils <binutils at sourceware dot org>
- Date: Mon, 15 Dec 2008 16:47:04 -0800
- Subject: [gold][patch] Fix plugin API so that add_symbols is not required
This patch fixes the gold plugin API so that the add_symbols callback
does not need to be called if the claimed file has no global symbols.
Previously, gold would issue a link error in this case and then go on
to try to process the claimed file as an ordinary object.
The patch also moves the LDPT_MESSAGE entry to the front of the
transfer vector so that the plugin can use that API while processing
subsequent entries, and fixes a possible array bounds error if the
plugin asks for more symbols than it provided.
OK?
-cary
* plugin.cc (Plugin::load): Move LDPT_MESSAGE to front of transfer
vector.
(Plugin_manager::claim_file): Create plugin object even if
plugin did not call the add_symbols callback.
(Plugin_obj::get_symbol_resolution_info): Guard against plugin
asking for more symbols than were added.
* testsuite/Makefile.am (plugin_test_1): Add test case with
no global symbols.
(empty.syms): New target.
* testsuite/Makefile.in: Regenerate.
* testsuite/plugin_test.c (claim_file_hook): Add new debug
message. Don't call add_symbols if no globals.
(all_symbols_read_hook): Don't provide replacement for empty
claimed file.
Index: plugin.cc
===================================================================
RCS file: /cvs/src/src/gold/plugin.cc,v
retrieving revision 1.4
diff -u -p -r1.4 plugin.cc
--- plugin.cc 5 Dec 2008 21:34:50 -0000 1.4
+++ plugin.cc 16 Dec 2008 00:33:58 -0000
@@ -116,7 +116,13 @@ Plugin::load()
int tv_size = this->args_.size() + tv_fixed_size;
ld_plugin_tv *tv = new ld_plugin_tv[tv_size];
+ // Put LDPT_MESSAGE at the front of the list so the plugin can use it
+ // while processing subsequent entries.
int i = 0;
+ tv[i].tv_tag = LDPT_MESSAGE;
+ tv[i].tv_u.tv_message = message;
+
+ ++i;
tv[i].tv_tag = LDPT_API_VERSION;
tv[i].tv_u.tv_val = LD_PLUGIN_API_VERSION;
@@ -165,10 +171,6 @@ Plugin::load()
tv[i].tv_u.tv_add_input_file = add_input_file;
++i;
- tv[i].tv_tag = LDPT_MESSAGE;
- tv[i].tv_u.tv_message = message;
-
- ++i;
tv[i].tv_tag = LDPT_NULL;
tv[i].tv_u.tv_val = 0;
@@ -265,14 +267,13 @@ Plugin_manager::claim_file(Input_file* i
{
if ((*this->current_)->claim_file(&this->plugin_input_file_))
{
- if (this->objects_.size() <= handle)
- {
- gold_error(_("%s: plugin claimed the file "
- "but did not provide any symbols"),
- this->plugin_input_file_.name);
- return NULL;
- }
- return this->objects_[handle];
+ if (this->objects_.size() > handle)
+ return this->objects_[handle];
+
+ // If the plugin claimed the file but did not call the
+ // add_symbols callback, we need to create the Pluginobj now.
+ Pluginobj* obj = this->make_plugin_object(handle);
+ return obj;
}
}
@@ -369,7 +370,7 @@ Pluginobj::Pluginobj(const std::string&
ld_plugin_status
Pluginobj::get_symbol_resolution_info(int nsyms, ld_plugin_symbol* syms) const
{
- if (this->nsyms_ == 0)
+ if (nsyms > this->nsyms_)
return LDPS_NO_SYMS;
for (int i = 0; i < nsyms; i++)
{
Index: testsuite/Makefile.am
===================================================================
RCS file: /cvs/src/src/gold/testsuite/Makefile.am,v
retrieving revision 1.80
diff -u -p -r1.80 Makefile.am
--- testsuite/Makefile.am 5 Dec 2008 21:34:50 -0000 1.80
+++ testsuite/Makefile.am 16 Dec 2008 00:33:58 -0000
@@ -958,8 +958,8 @@ check_PROGRAMS += plugin_test_1
check_SCRIPTS += plugin_test_1.sh
check_DATA += plugin_test_1.err
MOSTLYCLEANFILES += plugin_test_1.err
-plugin_test_1: two_file_test_main.o two_file_test_1.syms
two_file_test_1b.syms two_file_test_2.syms gcctestdir/ld
plugin_test.so
- $(CXXLINK) -Bgcctestdir/
-Wl,--no-demangle,--plugin,"./plugin_test.so",--plugin-opt,"_Z4f13iv"
two_file_test_main.o two_file_test_1.syms two_file_test_1b.syms
two_file_test_2.syms 2>plugin_test_1.err
+plugin_test_1: two_file_test_main.o two_file_test_1.syms
two_file_test_1b.syms two_file_test_2.syms empty.syms gcctestdir/ld
plugin_test.so
+ $(CXXLINK) -Bgcctestdir/
-Wl,--no-demangle,--plugin,"./plugin_test.so",--plugin-opt,"_Z4f13iv"
two_file_test_main.o two_file_test_1.syms two_file_test_1b.syms
two_file_test_2.syms empty.syms 2>plugin_test_1.err
plugin_test_1.err: plugin_test_1
@touch plugin_test_1.err
@@ -985,6 +985,9 @@ two_file_test_1b.syms: two_file_test_1b.
$(TEST_READELF) -sW $< >$@ 2>/dev/null
two_file_test_2.syms: two_file_test_2.o
$(TEST_READELF) -sW $< >$@ 2>/dev/null
+empty.syms:
+ @echo "" >empty.syms
+ @echo "Symbol table" >>empty.syms
endif PLUGINS
Index: testsuite/Makefile.in
===================================================================
RCS file: /cvs/src/src/gold/testsuite/Makefile.in,v
retrieving revision 1.85
diff -u -p -r1.85 Makefile.in
--- testsuite/Makefile.in 5 Dec 2008 21:34:54 -0000 1.85
+++ testsuite/Makefile.in 16 Dec 2008 00:33:58 -0000
@@ -1463,9 +1463,9 @@ $(srcdir)/Makefile.in: @MAINTAINER_MODE_
exit 1;; \
esac; \
done; \
- echo ' cd $(top_srcdir) && $(AUTOMAKE) --gnu testsuite/Makefile'; \
+ echo ' cd $(top_srcdir) && $(AUTOMAKE) --foreign testsuite/Makefile'; \
cd $(top_srcdir) && \
- $(AUTOMAKE) --gnu testsuite/Makefile
+ $(AUTOMAKE) --foreign testsuite/Makefile
.PRECIOUS: Makefile
Makefile: $(srcdir)/Makefile.in $(top_builddir)/config.status
@case '$?' in \
@@ -2453,8 +2453,8 @@ uninstall-am: uninstall-info-am
@GCC_TRUE@@NATIVE_LINKER_TRUE@alt/thin_archive_test_4.o: thin_archive_test_4.cc
@GCC_TRUE@@NATIVE_LINKER_TRUE@ test -d alt || mkdir -p alt
@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXCOMPILE) -c -o $@ $<
-@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_test_1:
two_file_test_main.o two_file_test_1.syms two_file_test_1b.syms
two_file_test_2.syms gcctestdir/ld plugin_test.so
-@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@ $(CXXLINK) -Bgcctestdir/
-Wl,--no-demangle,--plugin,"./plugin_test.so",--plugin-opt,"_Z4f13iv"
two_file_test_main.o two_file_test_1.syms two_file_test_1b.syms
two_file_test_2.syms 2>plugin_test_1.err
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_test_1:
two_file_test_main.o two_file_test_1.syms two_file_test_1b.syms
two_file_test_2.syms empty.syms gcctestdir/ld plugin_test.so
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@ $(CXXLINK) -Bgcctestdir/
-Wl,--no-demangle,--plugin,"./plugin_test.so",--plugin-opt,"_Z4f13iv"
two_file_test_main.o two_file_test_1.syms two_file_test_1b.syms
two_file_test_2.syms empty.syms 2>plugin_test_1.err
@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_test_1.err: plugin_test_1
@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@ @touch plugin_test_1.err
@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@plugin_test_2:
two_file_test_main.o two_file_test_1.syms two_file_test_1b.syms
two_file_shared_2.so gcctestdir/ld plugin_test.so
@@ -2475,6 +2475,9 @@ uninstall-am: uninstall-info-am
@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@ $(TEST_READELF) -sW $<
>$@ 2>/dev/null
@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@two_file_test_2.syms:
two_file_test_2.o
@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@ $(TEST_READELF) -sW $<
>$@ 2>/dev/null
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@empty.syms:
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@ @echo "" >empty.syms
+@GCC_TRUE@@NATIVE_LINKER_TRUE@@PLUGINS_TRUE@ @echo "Symbol table" >>empty.syms
# Tell versions [3.59,3.63) of GNU make to not export all variables.
# Otherwise a system limit (for SysV at least) may be exceeded.
.NOEXPORT:
Index: testsuite/plugin_test.c
===================================================================
RCS file: /cvs/src/src/gold/testsuite/plugin_test.c,v
retrieving revision 1.1
diff -u -p -r1.1 plugin_test.c
--- testsuite/plugin_test.c 19 Sep 2008 22:54:57 -0000 1.1
+++ testsuite/plugin_test.c 16 Dec 2008 00:33:58 -0000
@@ -319,7 +319,11 @@ claim_file_hook (const struct ld_plugin_
last_claimed_file->next = claimed_file;
last_claimed_file = claimed_file;
- (*add_symbols)(file->handle, nsyms, syms);
+ (*message)(LDPL_INFO, "%s: claiming file, adding %d symbols",
+ file->name, nsyms);
+
+ if (nsyms > 0)
+ (*add_symbols)(file->handle, nsyms, syms);
*claimed = 1;
return LDPS_OK;
@@ -398,6 +402,8 @@ all_symbols_read_hook(void)
claimed_file != NULL;
claimed_file = claimed_file->next)
{
+ if (claimed_file->nsyms == 0)
+ continue;
if (strlen(claimed_file->name) >= sizeof(buf))
{
(*message)(LDPL_FATAL, "%s: filename too long", claimed_file->name);