diff options
| -rw-r--r-- | gold/ChangeLog | 19 | ||||
| -rw-r--r-- | gold/layout.cc | 41 | ||||
| -rw-r--r-- | gold/layout.h | 65 | ||||
| -rw-r--r-- | gold/object.cc | 67 | ||||
| -rw-r--r-- | gold/object.h | 28 | ||||
| -rw-r--r-- | gold/plugin.cc | 7 |
6 files changed, 126 insertions, 101 deletions
diff --git a/gold/ChangeLog b/gold/ChangeLog index cac3405..cbd3d4b 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,22 @@ +2009-03-01 Mikolaj Zalewski <mikolajz@google.com> + + * layout.cc (Layout::find_or_add_kept_section): New function. + (Layout::add_comdat): Removed. + * layout.h (struct Kept_section): Move out of class Layout. + Remove trailing underscores from field names. Add group_sections + field. Rename group_ field to is_group. Change all uses. + (class Layout): Declare find_or_add_kept_section, not add_comdat. + * object.cc (Sized_relobj::Sized_relobj): Don't initialize + comdat_groups_ field. + (Sized_relobj::include_section_group): Use + find_or_add_kept_section and Kept_section::group_sections. + (Sized_relobj::include_linkonce_section): Likewise. + * object.cc (class Sized_relobj): Don't define Comdat_group or + Comdat_group_table. Remove find_comdat_group and + add_comdat_group. Remove comdat_groups_ field. + * plugin.cc (include_comdat_group): Use + Layout::find_or_add_kept_section. + 2009-02-28 Ian Lance Taylor <iant@google.com> * README: --gc-sections and map files are now supported. Document diff --git a/gold/layout.cc b/gold/layout.cc index 01b7c87..df74df3 100644 --- a/gold/layout.cc +++ b/gold/layout.cc @@ -2930,46 +2930,50 @@ Layout::output_section_name(const char* name, size_t* plen) return name; } -// Record the signature of a comdat section, and return whether to -// include it in the link. If GROUP is true, this is a regular -// section group. If GROUP is false, this is a group signature -// derived from the name of a linkonce section. We want linkonce -// signatures and group signatures to block each other, but we don't -// want a linkonce signature to block another linkonce signature. +// Check if a comdat group or .gnu.linkonce section with the given +// NAME is selected for the link. If there is already a section, +// *KEPT_SECTION is set to point to the signature and the function +// returns false. Otherwise, the CANDIDATE signature is recorded for +// this NAME in the layout object, *KEPT_SECTION is set to the +// internal copy and the function return false. In some cases, with +// CANDIDATE->GROUP_ being false, KEPT_SECTION can point back to +// CANDIDATE. bool -Layout::add_comdat(Relobj* object, unsigned int shndx, - const std::string& signature, bool group) +Layout::find_or_add_kept_section(const std::string name, + Kept_section* candidate, + Kept_section** kept_section) { - Kept_section kept(object, shndx, group); std::pair<Signatures::iterator, bool> ins( - this->signatures_.insert(std::make_pair(signature, kept))); + this->signatures_.insert(std::make_pair(name, *candidate))); + if (kept_section) + *kept_section = &ins.first->second; if (ins.second) { // This is the first time we've seen this signature. return true; } - if (ins.first->second.group_) + if (ins.first->second.is_group) { // We've already seen a real section group with this signature. // If the kept group is from a plugin object, and we're in // the replacement phase, accept the new one as a replacement. - if (ins.first->second.object_ == NULL + if (ins.first->second.object == NULL && parameters->options().plugins()->in_replacement_phase()) { - ins.first->second = kept; + ins.first->second = *candidate; return true; } return false; } - else if (group) + else if (candidate->is_group) { // This is a real section group, and we've already seen a // linkonce section with this signature. Record that we've seen // a section group, and don't include this section group. - ins.first->second.group_ = true; + ins.first->second.is_group = true; return false; } else @@ -2977,6 +2981,7 @@ Layout::add_comdat(Relobj* object, unsigned int shndx, // We've already seen a linkonce section and this is a linkonce // section. These don't block each other--this may be the same // symbol name with different section types. + *kept_section = candidate; return true; } } @@ -2991,8 +2996,8 @@ Layout::find_kept_object(const std::string& signature, if (p == this->signatures_.end()) return NULL; if (pshndx != NULL) - *pshndx = p->second.shndx_; - return p->second.object_; + *pshndx = p->second.shndx; + return p->second.object; } // Store the allocated sections into the section list. @@ -3101,7 +3106,7 @@ Layout::write_sections_after_input_sections(Output_file* of) { off_t off = this->output_file_size_; off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS); - + // Now that we've finalized the names, we can finalize the shstrab. off = this->set_section_offsets(off, diff --git a/gold/layout.h b/gold/layout.h index ca8b7c7..ca0f89a 100644 --- a/gold/layout.h +++ b/gold/layout.h @@ -1,6 +1,6 @@ // layout.h -- lay out output file sections for gold -*- C++ -*- -// Copyright 2006, 2007, 2008 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. // Written by Ian Lance Taylor <iant@google.com>. // This file is part of gold. @@ -89,6 +89,37 @@ class Layout_task_runner : public Task_function_runner Mapfile* mapfile_; }; +// This struct holds information about the comdat or .gnu.linkonce +// that will be kept. + +struct Kept_section +{ + Kept_section() + : object(NULL), shndx(0), is_group(false), group_sections(NULL) + { } + Kept_section(Relobj* a_object, unsigned int a_shndx, bool a_is_group) + : object(a_object), shndx(a_shndx), is_group(a_is_group), + group_sections(NULL) + { } + + typedef Unordered_map<std::string, unsigned int> Comdat_group; + + // The object containing the comdat or .gnu.linkonce. + Relobj* object; + // Index to the group section for comdats and the section itself for + // .gnu.linkonce. + unsigned int shndx; + // The Kept_sections are values of a mapping, that maps names to + // them. This field is true if this struct is associated with the + // name of a comdat or .gnu.linkonce, false if it is associated with + // the name of a symbol obtained from the .gnu.linkonce.* name + // through some heuristics. + bool is_group; + // For comdats, a map from names of the sections in the group to + // indexes in OBJECT_. NULL for .gnu.linkonce. + Comdat_group* group_sections; +}; + // This class handles the details of laying out input sections. class Layout @@ -225,18 +256,24 @@ class Layout { // Debugging sections can only be recognized by name. return (strncmp(name, ".debug", sizeof(".debug") - 1) == 0 - || strncmp(name, ".gnu.linkonce.wi.", + || strncmp(name, ".gnu.linkonce.wi.", sizeof(".gnu.linkonce.wi.") - 1) == 0 || strncmp(name, ".line", sizeof(".line") - 1) == 0 || strncmp(name, ".stab", sizeof(".stab") - 1) == 0); } - // Record the signature of a comdat section, and return whether to - // include it in the link. The GROUP parameter is true for a - // section group signature, false for a signature derived from a - // .gnu.linkonce section. + // Check if a comdat group or .gnu.linkonce section with the given + // NAME is selected for the link. If there is already a section, + // *KEPT_SECTION is set to point to the signature and the function + // returns false. Otherwise, the CANDIDATE signature is recorded + // for this NAME in the layout object, *KEPT_SECTION is set to the + // internal copy and the function return false. In some cases, with + // CANDIDATE->GROUP_ being false, KEPT_SECTION can point back to + // CANDIDATE. bool - add_comdat(Relobj*, unsigned int, const std::string&, bool group); + find_or_add_kept_section(const std::string name, + Kept_section* candidate, + Kept_section** kept_section); // Find the given comdat signature, and return the object and section // index of the kept group. @@ -577,19 +614,7 @@ class Layout static bool segment_precedes(const Output_segment* seg1, const Output_segment* seg2); - // A mapping used for group signatures. - struct Kept_section - { - Kept_section() - : object_(NULL), shndx_(0), group_(false) - { } - Kept_section(Relobj* object, unsigned int shndx, bool group) - : object_(object), shndx_(shndx), group_(group) - { } - Relobj* object_; - unsigned int shndx_; - bool group_; - }; + // A mapping used for kept comdats/.gnu.linkonce group signatures. typedef Unordered_map<std::string, Kept_section> Signatures; // Mapping from input section name/type/flags to output section. We diff --git a/gold/object.cc b/gold/object.cc index c70fdce..9cea076 100644 --- a/gold/object.cc +++ b/gold/object.cc @@ -327,7 +327,6 @@ Sized_relobj<size, big_endian>::Sized_relobj( local_values_(), local_got_offsets_(), kept_comdat_sections_(), - comdat_groups_(), has_eh_frame_(false) { } @@ -674,29 +673,25 @@ Sized_relobj<size, big_endian>::include_section_group( // Record this section group in the layout, and see whether we've already // seen one with the same signature. - bool include_group = ((flags & elfcpp::GRP_COMDAT) == 0 - || layout->add_comdat(this, index, signature, true)); - + bool include_group; Sized_relobj<size, big_endian>* kept_object = NULL; - Comdat_group* kept_group = NULL; + Kept_section::Comdat_group* kept_group = NULL; - if (!include_group) - { - // This group is being discarded. Find the object and group - // that was kept in its place. - unsigned int kept_group_index = 0; - Relobj* kept_relobj = layout->find_kept_object(signature, - &kept_group_index); - kept_object = static_cast<Sized_relobj<size, big_endian>*>(kept_relobj); - if (kept_object != NULL) - kept_group = kept_object->find_comdat_group(kept_group_index); - } - else if (flags & elfcpp::GRP_COMDAT) + if ((flags & elfcpp::GRP_COMDAT) == 0) + include_group = true; + else { - // This group is being kept. Create the table to map section names - // to section indexes and add it to the table of groups. - kept_group = new Comdat_group(); - this->add_comdat_group(index, kept_group); + Kept_section this_group(this, index, true); + Kept_section *kept_section_group; + include_group = layout->find_or_add_kept_section(signature, + &this_group, + &kept_section_group); + if (include_group) + kept_section_group->group_sections = new Kept_section::Comdat_group; + + kept_group = kept_section_group->group_sections; + kept_object = (static_cast<Sized_relobj<size, big_endian>*> + (kept_section_group->object)); } size_t count = shdr.get_sh_size() / sizeof(elfcpp::Elf_Word); @@ -745,7 +740,8 @@ Sized_relobj<size, big_endian>::include_section_group( { // Find the corresponding kept section, and store that info // in the discarded section table. - Comdat_group::const_iterator p = kept_group->find(mname); + Kept_section::Comdat_group::const_iterator p = + kept_group->find(mname); if (p != kept_group->end()) { Kept_comdat_section* kept = @@ -808,8 +804,12 @@ Sized_relobj<size, big_endian>::include_linkonce_section( symname = strrchr(name, '.') + 1; std::string sig1(symname); std::string sig2(name); - bool include1 = layout->add_comdat(this, index, sig1, false); - bool include2 = layout->add_comdat(this, index, sig2, true); + Kept_section candidate1(this, index, false); + Kept_section candidate2(this, index, true); + Kept_section* kept1; + Kept_section* kept2; + bool include1 = layout->find_or_add_kept_section(sig1, &candidate1, &kept1); + bool include2 = layout->find_or_add_kept_section(sig2, &candidate2, &kept2); if (!include2) { @@ -817,12 +817,12 @@ Sized_relobj<size, big_endian>::include_linkonce_section( // name (i.e., the kept section was also a linkonce section). // In this case, the section index stored with the layout object // is the linkonce section that was kept. - unsigned int kept_group_index = 0; - Relobj* kept_relobj = layout->find_kept_object(sig2, &kept_group_index); + unsigned int kept_group_index = kept2->shndx; + Relobj* kept_relobj = kept2->object; if (kept_relobj != NULL) { - Sized_relobj<size, big_endian>* kept_object - = static_cast<Sized_relobj<size, big_endian>*>(kept_relobj); + Sized_relobj<size, big_endian>* kept_object = + static_cast<Sized_relobj<size, big_endian>*>(kept_relobj); Kept_comdat_section* kept = new Kept_comdat_section(kept_object, kept_group_index); this->set_kept_comdat_section(index, kept); @@ -837,17 +837,16 @@ Sized_relobj<size, big_endian>::include_linkonce_section( // this linkonce section. We'll handle the simple case where // the group has only one member section. Otherwise, it's not // worth the effort. - unsigned int kept_group_index = 0; - Relobj* kept_relobj = layout->find_kept_object(sig1, &kept_group_index); + Relobj* kept_relobj = kept1->object; if (kept_relobj != NULL) { Sized_relobj<size, big_endian>* kept_object = - static_cast<Sized_relobj<size, big_endian>*>(kept_relobj); - Comdat_group* kept_group = - kept_object->find_comdat_group(kept_group_index); + static_cast<Sized_relobj<size, big_endian>*>(kept_relobj); + Kept_section::Comdat_group* kept_group = kept1->group_sections; if (kept_group != NULL && kept_group->size() == 1) { - Comdat_group::const_iterator p = kept_group->begin(); + Kept_section::Comdat_group::const_iterator p = + kept_group->begin(); gold_assert(p != kept_group->end()); Kept_comdat_section* kept = new Kept_comdat_section(kept_object, p->second); diff --git a/gold/object.h b/gold/object.h index 9e4c66f..2e49fd0 100644 --- a/gold/object.h +++ b/gold/object.h @@ -1584,32 +1584,6 @@ class Sized_relobj : public Relobj typedef std::map<unsigned int, Kept_comdat_section*> Kept_comdat_section_table; - // Information needed to keep track of kept comdat groups. This is - // simply a map from the section name to its section index. This may - // not be a one-to-one mapping, but we ignore that possibility since - // this is used only to attempt to handle stray relocations from - // non-comdat debug sections that refer to comdat loadable sections. - typedef Unordered_map<std::string, unsigned int> Comdat_group; - - // A map from group section index to the table of group members. - typedef std::map<unsigned int, Comdat_group*> Comdat_group_table; - - // Find a comdat group table given its group section SHNDX. - Comdat_group* - find_comdat_group(unsigned int shndx) const - { - Comdat_group_table::const_iterator p = - this->comdat_groups_.find(shndx); - if (p != this->comdat_groups_.end()) - return p->second; - return NULL; - } - - // Record a new comdat group whose group section index is SHNDX. - void - add_comdat_group(unsigned int shndx, Comdat_group* group) - { this->comdat_groups_[shndx] = group; } - // Adjust a section index if necessary. unsigned int adjust_shndx(unsigned int shndx) @@ -1823,8 +1797,6 @@ class Sized_relobj : public Relobj std::vector<Address> section_offsets_; // Table mapping discarded comdat sections to corresponding kept sections. Kept_comdat_section_table kept_comdat_sections_; - // Table of kept comdat groups. - Comdat_group_table comdat_groups_; // Whether this object has a GNU style .eh_frame section. bool has_eh_frame_; // The list of sections whose layout was deferred. diff --git a/gold/plugin.cc b/gold/plugin.cc index e58751e..4550371 100644 --- a/gold/plugin.cc +++ b/gold/plugin.cc @@ -506,7 +506,12 @@ Pluginobj::include_comdat_group(std::string comdat_key, Layout* layout) // If this is the first time we've seen this comdat key, ask the // layout object whether it should be included. if (ins.second) - ins.first->second = layout->add_comdat(NULL, 1, comdat_key, true); + { + Kept_section to_add(NULL, 1, true); + ins.first->second = layout->find_or_add_kept_section(comdat_key, + &to_add, + NULL); + } return ins.first->second; } |