diff options
| -rw-r--r-- | gold/ChangeLog | 20 | ||||
| -rw-r--r-- | gold/gc.h | 46 | ||||
| -rw-r--r-- | gold/gold.h | 17 | ||||
| -rw-r--r-- | gold/layout.cc | 15 | ||||
| -rw-r--r-- | gold/object.cc | 8 | ||||
| -rw-r--r-- | gold/testsuite/Makefile.am | 10 | ||||
| -rw-r--r-- | gold/testsuite/Makefile.in | 11 | ||||
| -rw-r--r-- | gold/testsuite/gc_orphan_section_test.cc | 36 | ||||
| -rwxr-xr-x | gold/testsuite/gc_orphan_section_test.sh | 46 |
9 files changed, 198 insertions, 11 deletions
diff --git a/gold/ChangeLog b/gold/ChangeLog index b52505f..65c0c90 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,23 @@ +2010-01-06 Sriraman Tallam <tmsriram@google.com> + + * gc.h (Garbage_collection::Cident_section_map): New typedef. + (Garbage_collection::cident_sections): New function. + (Garbage_collection::add_cident_section): New function. + (Garbage_collection::cident_sections_): New member. + (gc_process_relocs): Add references to sections whose names are C + identifiers. + * gold.h (cident_section_start_prefix): New constant. + (cident_section_stop_prefix): New constant. + (is_cident): New function. + * layout.cc (Layout::define_section_symbols): Replace string constants + with the newly defined constants. + * object.cc (Sized_relobj::do_layout): Track sections whose names are + C identifiers. + * testsuite/Makefile.am: Add gc_orphan_section_test. + * testsuite/Makefile.in: Regenerate. + * testsuite/gc_orphan_section_test.cc: New file. + * testsuite/gc_orphan_section_test.sh: New file. + 2010-01-06 Ian Lance Taylor <iant@google.com> PR 10980 @@ -60,6 +60,10 @@ class Garbage_collection typedef Unordered_set<Section_id, Section_id_hash> Sections_reachable; typedef std::map<Section_id, Sections_reachable> Section_ref; typedef std::queue<Section_id> Worklist_type; + // This maps the name of the section which can be represented as a C + // identifier (cident) to the list of sections that have that name. + // Different object files can have cident sections with the same name. + typedef std::map<std::string, Sections_reachable> Cident_section_map; Garbage_collection() : is_worklist_ready_(false) @@ -94,12 +98,23 @@ class Garbage_collection is_section_garbage(Object* obj, unsigned int shndx) { return (this->referenced_list().find(Section_id(obj, shndx)) == this->referenced_list().end()); } + + Cident_section_map* + cident_sections() + { return &cident_sections_; } + + void + add_cident_section(std::string section_name, + Section_id secn) + { this->cident_sections_[section_name].insert(secn); } + private: Worklist_type work_list_; bool is_worklist_ready_; Section_ref section_reloc_map_; Sections_reachable referenced_list_; + Cident_section_map cident_sections_; }; // Data to pass between successive invocations of do_layout @@ -161,6 +176,7 @@ gc_process_relocs( std::vector<Symbol*>* symvec = NULL; std::vector<std::pair<long long, long long> >* addendvec = NULL; bool is_icf_tracked = false; + const char* cident_section_name = NULL; if (parameters->options().icf_enabled() && is_section_foldable_candidate(src_obj->section_name(src_indx).c_str())) @@ -218,6 +234,19 @@ gc_process_relocs( if (!is_ordinary) continue; Section_id dst_id(dst_obj, dst_indx); + // If the symbol name matches '__start_XXX' then the section with + // the C identifier like name 'XXX' should not be garbage collected. + // A similar treatment to symbols with the name '__stop_XXX'. + if (is_prefix_of(cident_section_start_prefix, gsym->name())) + { + cident_section_name = (gsym->name() + + strlen(cident_section_start_prefix)); + } + else if (is_prefix_of(cident_section_stop_prefix, gsym->name())) + { + cident_section_name = (gsym->name() + + strlen(cident_section_stop_prefix)); + } if (is_icf_tracked) { (*secvec).push_back(dst_id); @@ -245,6 +274,23 @@ gc_process_relocs( Garbage_collection::Sections_reachable& v(map_it->second); v.insert(dst_id); } + if (cident_section_name != NULL) + { + Garbage_collection::Cident_section_map::iterator ele = + symtab->gc()->cident_sections()->find(std::string(cident_section_name)); + if (ele == symtab->gc()->cident_sections()->end()) + continue; + Garbage_collection::Sections_reachable& + v(symtab->gc()->section_reloc_map()[src_id]); + Garbage_collection::Sections_reachable& cident_secn(ele->second); + for (Garbage_collection::Sections_reachable::iterator it_v + = cident_secn.begin(); + it_v != cident_secn.end(); + ++it_v) + { + v.insert(*it_v); + } + } } } return; diff --git a/gold/gold.h b/gold/gold.h index dc5a1c1..5c98de0 100644 --- a/gold/gold.h +++ b/gold/gold.h @@ -1,6 +1,6 @@ // gold.h -- general definitions for gold -*- C++ -*- -// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor <iant@google.com>. // This file is part of gold. @@ -349,6 +349,21 @@ is_prefix_of(const char* prefix, const char* str) return strncmp(prefix, str, strlen(prefix)) == 0; } +const char* const cident_section_start_prefix = "__start_"; +const char* const cident_section_stop_prefix = "__stop_"; + +// Returns true if the name is a valid C identifier +inline bool +is_cident(const char* name) +{ + return (name[strspn(name, + ("0123456789" + "ABCDEFGHIJKLMNOPWRSTUVWXYZ" + "abcdefghijklmnopqrstuvwxyz" + "_"))] + == '\0'); +} + // We sometimes need to hash strings. Ideally we should use std::tr1::hash or // __gnu_cxx::hash on some systems but there is no guarantee that either // one is available. For portability, we define simple string hash functions. diff --git a/gold/layout.cc b/gold/layout.cc index f3deb9a..f427af5 100644 --- a/gold/layout.cc +++ b/gold/layout.cc @@ -1,6 +1,6 @@ // layout.cc -- lay out output file sections for gold -// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor <iant@google.com>. // This file is part of gold. @@ -1232,16 +1232,13 @@ Layout::define_section_symbols(Symbol_table* symtab) ++p) { const char* const name = (*p)->name(); - if (name[strspn(name, - ("0123456789" - "ABCDEFGHIJKLMNOPWRSTUVWXYZ" - "abcdefghijklmnopqrstuvwxyz" - "_"))] - == '\0') + if (is_cident(name)) { const std::string name_string(name); - const std::string start_name("__start_" + name_string); - const std::string stop_name("__stop_" + name_string); + const std::string start_name(cident_section_start_prefix + + name_string); + const std::string stop_name(cident_section_stop_prefix + + name_string); symtab->define_in_output_data(start_name.c_str(), NULL, // version diff --git a/gold/object.cc b/gold/object.cc index 3fedcf8..89ff34c 100644 --- a/gold/object.cc +++ b/gold/object.cc @@ -1180,6 +1180,14 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab, { symtab->gc()->worklist().push(Section_id(this, i)); } + // If the section name XXX can be represented as a C identifier + // it cannot be discarded if there are references to + // __start_XXX and __stop_XXX symbols. These need to be + // specially handled. + if (is_cident(name)) + { + symtab->gc()->add_cident_section(name, Section_id(this, i)); + } } // When doing a relocatable link we are going to copy input diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am index 7b5532e..2bf5bbe 100644 --- a/gold/testsuite/Makefile.am +++ b/gold/testsuite/Makefile.am @@ -139,6 +139,16 @@ gc_tls_test:gc_tls_test.o gcctestdir/ld gc_tls_test.stdout: gc_tls_test $(TEST_NM) -C gc_tls_test > gc_tls_test.stdout +check_SCRIPTS += gc_orphan_section_test.sh +check_DATA += gc_orphan_section_test.stdout +MOSTLYCLEANFILES += gc_orphan_section_test +gc_orphan_section_test.o: gc_orphan_section_test.cc + $(CXXCOMPILE) -O0 -c -g -o $@ $< +gc_orphan_section_test:gc_orphan_section_test.o gcctestdir/ld + $(CXXLINK) -Bgcctestdir/ -Wl,--gc-sections gc_orphan_section_test.o +gc_orphan_section_test.stdout: gc_orphan_section_test + $(TEST_NM) gc_orphan_section_test > gc_orphan_section_test.stdout + check_SCRIPTS += icf_test.sh check_DATA += icf_test.stdout MOSTLYCLEANFILES += icf_test diff --git a/gold/testsuite/Makefile.in b/gold/testsuite/Makefile.in index 291eab7..21fca3d 100644 --- a/gold/testsuite/Makefile.in +++ b/gold/testsuite/Makefile.in @@ -57,6 +57,7 @@ check_PROGRAMS = object_unittest$(EXEEXT) binary_unittest$(EXEEXT) \ # and --dynamic-list-cpp-typeinfo @GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_1 = incremental_test.sh \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ gc_comdat_test.sh gc_tls_test.sh \ +@GCC_TRUE@@NATIVE_LINKER_TRUE@ gc_orphan_section_test.sh \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_test.sh \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_keep_unique_test.sh \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_safe_test.sh \ @@ -82,6 +83,7 @@ check_PROGRAMS = object_unittest$(EXEEXT) binary_unittest$(EXEEXT) \ @GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_2 = incremental_test.stdout \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ gc_comdat_test.stdout \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ gc_tls_test.stdout \ +@GCC_TRUE@@NATIVE_LINKER_TRUE@ gc_orphan_section_test.stdout \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_test.stdout \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_keep_unique_test.stdout \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_safe_test.stdout \ @@ -103,7 +105,8 @@ check_PROGRAMS = object_unittest$(EXEEXT) binary_unittest$(EXEEXT) \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ dynamic_list.stdout @GCC_TRUE@@NATIVE_LINKER_TRUE@am__append_3 = incremental_test \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ gc_comdat_test gc_tls_test \ -@GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_test icf_keep_unique_test \ +@GCC_TRUE@@NATIVE_LINKER_TRUE@ gc_orphan_section_test icf_test \ +@GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_keep_unique_test \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ icf_safe_test \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ two_file_shared.dbg \ @GCC_TRUE@@NATIVE_LINKER_TRUE@ alt/weak_undef_lib.so @@ -2582,6 +2585,12 @@ uninstall-am: @GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXLINK) -Bgcctestdir/ -Wl,--gc-sections gc_tls_test.o @GCC_TRUE@@NATIVE_LINKER_TRUE@gc_tls_test.stdout: gc_tls_test @GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_NM) -C gc_tls_test > gc_tls_test.stdout +@GCC_TRUE@@NATIVE_LINKER_TRUE@gc_orphan_section_test.o: gc_orphan_section_test.cc +@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXCOMPILE) -O0 -c -g -o $@ $< +@GCC_TRUE@@NATIVE_LINKER_TRUE@gc_orphan_section_test:gc_orphan_section_test.o gcctestdir/ld +@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXLINK) -Bgcctestdir/ -Wl,--gc-sections gc_orphan_section_test.o +@GCC_TRUE@@NATIVE_LINKER_TRUE@gc_orphan_section_test.stdout: gc_orphan_section_test +@GCC_TRUE@@NATIVE_LINKER_TRUE@ $(TEST_NM) gc_orphan_section_test > gc_orphan_section_test.stdout @GCC_TRUE@@NATIVE_LINKER_TRUE@icf_test.o: icf_test.cc @GCC_TRUE@@NATIVE_LINKER_TRUE@ $(CXXCOMPILE) -O0 -c -ffunction-sections -g -o $@ $< @GCC_TRUE@@NATIVE_LINKER_TRUE@icf_test: icf_test.o gcctestdir/ld diff --git a/gold/testsuite/gc_orphan_section_test.cc b/gold/testsuite/gc_orphan_section_test.cc new file mode 100644 index 0000000..3443f8d --- /dev/null +++ b/gold/testsuite/gc_orphan_section_test.cc @@ -0,0 +1,36 @@ +// gc_orphan_section_test.cc -- a test case for gold + +// Copyright 2010 Free Software Foundation, Inc. +// Written by Sriraman Tallam <tmsriram@google.com>. + +// 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. + +// The goal of this program is to verify if garbage collection does not +// discard orphan sections when references to them through __start_XXX +// and __stop_XXX are present. Here section _foo must not be gc'ed but +// _boo should be gc'ed. + +extern const int *__start__foo; +int foo __attribute__((__section__("_foo"))) = 1; +int boo __attribute__((__section__("_boo"))) = 1; + +int main() +{ + return *__start__foo; +} + diff --git a/gold/testsuite/gc_orphan_section_test.sh b/gold/testsuite/gc_orphan_section_test.sh new file mode 100755 index 0000000..6ce524d --- /dev/null +++ b/gold/testsuite/gc_orphan_section_test.sh @@ -0,0 +1,46 @@ +#!/bin/sh + +# gc_orphan_section_test.sh -- test --gc-sections + +# Copyright 2010 Free Software Foundation, Inc. +# Written by Sriraman Tallam <tmsriram@google.com>. + +# 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. + +# The goal of this program is to verify if gc-sections works as expected +# with orphan sections. +# File gc_orphan_sections_test.cc is in this test. This program checks if +# the orphan sections are retained when they are referenced through +# __start_XXX and __stop_XXX symbols. + +check() +{ + if grep -q " boo" "$1" + then + echo "Garbage collection failed to collect boo" + exit 1 + fi + grep_foo=`grep -q " foo" $1` + if [ $? != 0 ]; + then + echo "Garbage collection should not discard foo" + exit 1 + fi +} + +check gc_orphan_section_test.stdout |