X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gold%2Fcommon.cc;h=88a40f847e8cb4fad4ad40856f5f58870a2c97d2;hb=4a422785822ec9302f681c8fbc6ba2cc35231b09;hp=7ba8adc2697d68987e146b50aeb1df5f303b681f;hpb=dbe717effbdf31236088837f4686fd5ad5e71893;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/common.cc b/gold/common.cc index 7ba8adc269..88a40f847e 100644 --- a/gold/common.cc +++ b/gold/common.cc @@ -1,10 +1,31 @@ // common.cc -- handle common symbols for gold +// Copyright (C) 2006-2019 Free Software Foundation, Inc. +// Written by Ian Lance Taylor . + +// 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. + #include "gold.h" #include #include "workqueue.h" +#include "mapfile.h" #include "layout.h" #include "output.h" #include "symtab.h" @@ -15,38 +36,21 @@ namespace gold // Allocate_commons_task methods. -// This task allocates the common symbols. We need a lock on the -// symbol table. +// This task allocates the common symbols. We arrange to run it +// before anything else which needs to access the symbol table. -Task::Is_runnable_type -Allocate_commons_task::is_runnable(Workqueue*) +Task_token* +Allocate_commons_task::is_runnable() { - if (!this->symtab_lock_->is_writable()) - return IS_LOCKED; - return IS_RUNNABLE; + return NULL; } -// Return the locks we hold: one on the symbol table, and one blocker. +// Release a blocker. -class Allocate_commons_task::Allocate_commons_locker : public Task_locker -{ - public: - Allocate_commons_locker(Task_token& symtab_lock, Task* task, - Task_token& blocker, Workqueue* workqueue) - : symtab_locker_(symtab_lock, task), - blocker_(blocker, workqueue) - { } - - private: - Task_locker_write symtab_locker_; - Task_locker_block blocker_; -}; - -Task_locker* -Allocate_commons_task::locks(Workqueue* workqueue) +void +Allocate_commons_task::locks(Task_locker* tl) { - return new Allocate_commons_locker(*this->symtab_lock_, this, - *this->blocker_, workqueue); + tl->add(this, this->blocker_); } // Allocate the common symbols. @@ -54,24 +58,29 @@ Allocate_commons_task::locks(Workqueue* workqueue) void Allocate_commons_task::run(Workqueue*) { - this->symtab_->allocate_commons(this->options_, this->layout_); + this->symtab_->allocate_commons(this->layout_, this->mapfile_); } -// This class is used to sort the common symbol by size. We put the -// larger common symbols first. +// This class is used to sort the common symbol. We normally put the +// larger common symbols first. This can be changed by using +// --sort-commons, which tells the linker to sort by alignment. template class Sort_commons { public: - Sort_commons(const Symbol_table* symtab) - : symtab_(symtab) + Sort_commons(const Symbol_table* symtab, + Symbol_table::Sort_commons_order sort_order) + : symtab_(symtab), sort_order_(sort_order) { } bool operator()(const Symbol* a, const Symbol* b) const; private: + // The symbol table. const Symbol_table* symtab_; + // How to sort. + Symbol_table::Sort_commons_order sort_order_; }; template @@ -84,27 +93,51 @@ Sort_commons::operator()(const Symbol* pa, const Symbol* pb) const return true; const Symbol_table* symtab = this->symtab_; - const Sized_symbol* psa; - psa = symtab->get_sized_symbol SELECT_SIZE_NAME(size) (pa - SELECT_SIZE(size)); - const Sized_symbol* psb; - psb = symtab->get_sized_symbol SELECT_SIZE_NAME(size) (pb - SELECT_SIZE(size)); + const Sized_symbol* psa = symtab->get_sized_symbol(pa); + const Sized_symbol* psb = symtab->get_sized_symbol(pb); + // The size. typename Sized_symbol::Size_type sa = psa->symsize(); typename Sized_symbol::Size_type sb = psb->symsize(); + + // The alignment. + typename Sized_symbol::Value_type aa = psa->value(); + typename Sized_symbol::Value_type ab = psb->value(); + + if (this->sort_order_ == Symbol_table::SORT_COMMONS_BY_ALIGNMENT_DESCENDING) + { + if (aa < ab) + return false; + else if (ab < aa) + return true; + } + else if (this->sort_order_ + == Symbol_table::SORT_COMMONS_BY_ALIGNMENT_ASCENDING) + { + if (aa < ab) + return true; + else if (ab < aa) + return false; + } + else + gold_assert(this->sort_order_ + == Symbol_table::SORT_COMMONS_BY_SIZE_DESCENDING); + + // Sort by descending size. if (sa < sb) return false; - else if (sb > sa) + else if (sb < sa) return true; - // When the symbols are the same size, we sort them by alignment. - typename Sized_symbol::Value_type va = psa->value(); - typename Sized_symbol::Value_type vb = psb->value(); - if (va < vb) - return false; - else if (vb > va) - return true; + if (this->sort_order_ == Symbol_table::SORT_COMMONS_BY_SIZE_DESCENDING) + { + // When the symbols are the same size, we sort them by + // alignment, largest alignment first. + if (aa < ab) + return false; + else if (ab < aa) + return true; + } // Otherwise we stabilize the sort by sorting by name. return strcmp(psa->name(), psb->name()) < 0; @@ -113,33 +146,89 @@ Sort_commons::operator()(const Symbol* pa, const Symbol* pb) const // Allocate the common symbols. void -Symbol_table::allocate_commons(const General_options& options, Layout* layout) +Symbol_table::allocate_commons(Layout* layout, Mapfile* mapfile) { - if (this->get_size() == 32) - this->do_allocate_commons<32>(options, layout); - else if (this->get_size() == 64) - this->do_allocate_commons<64>(options, layout); + Sort_commons_order sort_order; + if (!parameters->options().user_set_sort_common()) + sort_order = SORT_COMMONS_BY_SIZE_DESCENDING; else - abort(); + { + const char* order = parameters->options().sort_common(); + if (*order == '\0' || strcmp(order, "descending") == 0) + sort_order = SORT_COMMONS_BY_ALIGNMENT_DESCENDING; + else if (strcmp(order, "ascending") == 0) + sort_order = SORT_COMMONS_BY_ALIGNMENT_ASCENDING; + else + { + gold_error("invalid --sort-common argument: %s", order); + sort_order = SORT_COMMONS_BY_SIZE_DESCENDING; + } + } + + if (parameters->target().get_size() == 32) + { +#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) + this->do_allocate_commons<32>(layout, mapfile, sort_order); +#else + gold_unreachable(); +#endif + } + else if (parameters->target().get_size() == 64) + { +#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) + this->do_allocate_commons<64>(layout, mapfile, sort_order); +#else + gold_unreachable(); +#endif + } + else + gold_unreachable(); } // Allocated the common symbols, sized version. template void -Symbol_table::do_allocate_commons(const General_options&, - Layout* layout) +Symbol_table::do_allocate_commons(Layout* layout, Mapfile* mapfile, + Sort_commons_order sort_order) { - typedef typename Sized_symbol::Value_type Value_type; - typedef typename Sized_symbol::Size_type Size_type; + if (!this->commons_.empty()) + this->do_allocate_commons_list(layout, COMMONS_NORMAL, + &this->commons_, mapfile, + sort_order); + if (!this->tls_commons_.empty()) + this->do_allocate_commons_list(layout, COMMONS_TLS, + &this->tls_commons_, mapfile, + sort_order); + if (!this->small_commons_.empty()) + this->do_allocate_commons_list(layout, COMMONS_SMALL, + &this->small_commons_, mapfile, + sort_order); + if (!this->large_commons_.empty()) + this->do_allocate_commons_list(layout, COMMONS_LARGE, + &this->large_commons_, mapfile, + sort_order); +} + +// Allocate the common symbols in a list. IS_TLS indicates whether +// these are TLS common symbols. +template +void +Symbol_table::do_allocate_commons_list( + Layout* layout, + Commons_section_type commons_section_type, + Commons_type* commons, + Mapfile* mapfile, + Sort_commons_order sort_order) +{ // We've kept a list of all the common symbols. But the symbol may // have been resolved to a defined symbol by now. And it may be a // forwarder. First remove all non-common symbols. bool any = false; uint64_t addralign = 0; - for (Commons_type::iterator p = this->commons_.begin(); - p != this->commons_.end(); + for (Commons_type::iterator p = commons->begin(); + p != commons->end(); ++p) { Symbol* sym = *p; @@ -153,10 +242,7 @@ Symbol_table::do_allocate_commons(const General_options&, else { any = true; - Sized_symbol* ssym; - ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) ( - sym - SELECT_SIZE(size)); + Sized_symbol* ssym = this->get_sized_symbol(sym); if (ssym->value() > addralign) addralign = ssym->value(); } @@ -164,47 +250,115 @@ Symbol_table::do_allocate_commons(const General_options&, if (!any) return; - // Sort the common symbols by size, so that they pack better into - // memory. - std::sort(this->commons_.begin(), this->commons_.end(), - Sort_commons(this)); + // Sort the common symbols. + std::sort(commons->begin(), commons->end(), + Sort_commons(this, sort_order)); + + // Place them in a newly allocated BSS section. + elfcpp::Elf_Xword flags = elfcpp::SHF_WRITE | elfcpp::SHF_ALLOC; + const char* name; + const char* ds_name; + switch (commons_section_type) + { + case COMMONS_NORMAL: + name = ".bss"; + ds_name = "** common"; + break; + case COMMONS_TLS: + flags |= elfcpp::SHF_TLS; + name = ".tbss"; + ds_name = "** tls common"; + break; + case COMMONS_SMALL: + flags |= parameters->target().small_common_section_flags(); + name = ".sbss"; + ds_name = "** small common"; + break; + case COMMONS_LARGE: + flags |= parameters->target().large_common_section_flags(); + name = ".lbss"; + ds_name = "** large common"; + break; + default: + gold_unreachable(); + } - // Place them in a newly allocated .bss section. + Output_data_space* poc; + Output_section* os; - Output_data_common *poc = new Output_data_common(addralign); + if (!parameters->incremental_update()) + { + poc = new Output_data_space(addralign, ds_name); + os = layout->add_output_section_data(name, elfcpp::SHT_NOBITS, flags, + poc, ORDER_INVALID, false); + } + else + { + // When doing an incremental update, we need to allocate each common + // directly from the output section's free list. + poc = NULL; + os = layout->find_output_section(name); + } - layout->add_output_section_data(".bss", elfcpp::SHT_NOBITS, - elfcpp::SHF_WRITE | elfcpp::SHF_ALLOC, - poc); + if (os != NULL) + { + if (commons_section_type == COMMONS_SMALL) + os->set_is_small_section(); + else if (commons_section_type == COMMONS_LARGE) + os->set_is_large_section(); + } // Allocate them all. off_t off = 0; - for (Commons_type::iterator p = this->commons_.begin(); - p != this->commons_.end(); + for (Commons_type::iterator p = commons->begin(); + p != commons->end(); ++p) { Symbol* sym = *p; if (sym == NULL) break; - Sized_symbol* ssym; - ssym = this->get_sized_symbol SELECT_SIZE_NAME(size) (sym - SELECT_SIZE(size)); + // Because we followed forwarding symbols above, but we didn't + // do it reliably before adding symbols to the list, it is + // possible for us to have the same symbol on the list twice. + // This can happen in the horrible case where a program defines + // a common symbol with the same name as a versioned libc + // symbol. That will show up here as a symbol which has already + // been allocated and is therefore no longer a common symbol. + if (!sym->is_common()) + continue; - off = align_address(off, ssym->value()); + Sized_symbol* ssym = this->get_sized_symbol(sym); - Size_type symsize = ssym->symsize(); - ssym->init(ssym->name(), poc, off, symsize, ssym->type(), - ssym->binding(), ssym->visibility(), ssym->nonvis(), - false); + // Record the symbol in the map file now, before we change its + // value. Pass the size in separately so that we don't have to + // templatize the map code, which is not performance sensitive. + if (mapfile != NULL) + mapfile->report_allocate_common(sym, ssym->symsize()); - off += symsize; + if (poc != NULL) + { + off = align_address(off, ssym->value()); + ssym->allocate_common(poc, off); + off += ssym->symsize(); + } + else + { + // For an incremental update, allocate from the free list. + off = os->allocate(ssym->symsize(), ssym->value()); + if (off == -1) + gold_fallback(_("out of patch space in section %s; " + "relink with --incremental-full"), + os->name()); + ssym->allocate_common(os, off); + } } - poc->set_common_size(off); + if (poc != NULL) + poc->set_current_data_size(off); - this->commons_.clear(); + commons->clear(); } } // End namespace gold.