From 21bb3914d64c5fb946423572fe895d2a08531030 Mon Sep 17 00:00:00 2001 From: Sriraman Tallam Date: Sat, 13 Feb 2010 02:04:21 +0000 Subject: 2010-02-12 Sriraman Tallam * arm.cc (Scan::local_reloc_may_be_function_pointer): New function. (Scan::global_reloc_may_be_function_pointer): New function. * sparc.cc (Scan::local_reloc_may_be_function_pointer): New function. (Scan::global_reloc_may_be_function_pointer): New function. * powerpc.cc (Scan::local_reloc_may_be_function_pointer): New function. (Scan::global_reloc_may_be_function_pointer): New function. * i386.cc (Scan::local_reloc_may_be_function_pointer): New function. (Scan::global_reloc_may_be_function_pointer): New function. * x86_64.cc (Scan::local_reloc_may_be_function_pointer): New function. (Scan::global_reloc_may_be_function_pointer): New function. (Scan::possible_function_pointer_reloc): New function. (Target_x86_64::can_check_for_function_pointers): New function. * gc.h (gc_process_relocs): Scan relocation types to determine if function pointers were taken for targets that support it. * icf.cc (Icf::find_identical_sections): Include functions for folding in safe ICF whose pointer is not taken. * icf.h (Secn_fptr_taken_set): New typedef. (fptr_section_id_): New member. (section_has_function_pointers): New function. (set_section_has_function_pointers): New function. (check_section_for_function_pointers): New function. * options.h: Fix comment for safe ICF option. * target.h (can_check_for_function_pointers): New function. * testsuite/Makefile.am: Add icf_safe_so_test test case. Modify icf_safe_test for X86-64. * testsuite/Makefile.in: Regenerate. * testsuite/icf_safe_so_test.cc: New file. * testsuite/icf_safe_so_test.sh: New file. * testsuite/icf_safe_test.cc (kept_func_3): New function. (main): Change to take pointer to function kept_func_3. * testsuite/icf_safe_test.sh (arch_specific_safe_fold): Check if safe folding is done correctly for X86-64. --- gold/gc.h | 46 +++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 41 insertions(+), 5 deletions(-) (limited to 'gold/gc.h') diff --git a/gold/gc.h b/gold/gc.h index 1ffb590..d4fd02e 100644 --- a/gold/gc.h +++ b/gold/gc.h @@ -163,18 +163,19 @@ inline void gc_process_relocs( Symbol_table* symtab, Layout*, - Target_type* , + Target_type* target, Sized_relobj* src_obj, unsigned int src_indx, const unsigned char* prelocs, size_t reloc_count, Output_section*, - bool , + bool, size_t local_count, const unsigned char* plocal_syms) { Object *dst_obj; unsigned int dst_indx; + Scan scan; typedef typename Reloc_types::Reloc Reltype; const int reloc_size = Reloc_types::reloc_size; @@ -186,8 +187,14 @@ gc_process_relocs( bool is_icf_tracked = false; const char* cident_section_name = NULL; + std::string src_section_name = (parameters->options().icf_enabled() + ? src_obj->section_name(src_indx) + : ""); + + bool check_section_for_function_pointers = false; + if (parameters->options().icf_enabled() - && is_section_foldable_candidate(src_obj->section_name(src_indx).c_str())) + && is_section_foldable_candidate(src_section_name.c_str())) { is_icf_tracked = true; Section_id src_id(src_obj, src_indx); @@ -196,11 +203,16 @@ gc_process_relocs( addendvec = &symtab->icf()->addend_reloc_list()[src_id]; } + check_section_for_function_pointers = + symtab->icf()->check_section_for_function_pointers(src_section_name, + target); + for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size) { Reltype reloc(prelocs); typename elfcpp::Elf_types::Elf_WXword r_info = reloc.get_r_info(); unsigned int r_sym = elfcpp::elf_r_sym(r_info); + unsigned int r_type = elfcpp::elf_r_type(r_info); typename elfcpp::Elf_types::Elf_Swxword addend = Reloc_types::get_reloc_addend_noerror(&reloc); @@ -225,6 +237,18 @@ gc_process_relocs( (*addendvec).push_back(std::make_pair(symvalue, static_cast(addend))); } + + // When doing safe folding, check to see if this relocation is that + // of a function pointer being taken. + if (check_section_for_function_pointers + && lsym.get_st_type() != elfcpp::STT_OBJECT + && scan.local_reloc_may_be_function_pointer(symtab, NULL, NULL, + src_obj, src_indx, + NULL, reloc, r_type, + lsym)) + symtab->icf()->set_section_has_function_pointers( + src_obj, lsym.get_st_shndx()); + if (shndx == src_indx) continue; } @@ -239,9 +263,21 @@ gc_process_relocs( bool is_ordinary; dst_obj = gsym->object(); dst_indx = gsym->shndx(&is_ordinary); + Section_id dst_id(dst_obj, dst_indx); + + // When doing safe folding, check to see if this relocation is that + // of a function pointer being taken. + if (check_section_for_function_pointers + && gsym->type() != elfcpp::STT_OBJECT + && (!is_ordinary + || scan.global_reloc_may_be_function_pointer( + symtab, NULL, NULL, src_obj, src_indx, NULL, reloc, + r_type, gsym))) + symtab->icf()->set_section_has_function_pointers(dst_obj, dst_indx); + 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'. @@ -265,7 +301,7 @@ gc_process_relocs( static_cast(sized_gsym->value()); (*addendvec).push_back(std::make_pair(symvalue, static_cast(addend))); - } + } } if (parameters->options().gc_sections()) { -- cgit v1.1