// object.cc -- support for an object file for linking in 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.
namespace gold
{
+// Struct Read_symbols_data.
+
+// Destroy any remaining File_view objects.
+
+Read_symbols_data::~Read_symbols_data()
+{
+ if (this->section_headers != NULL)
+ delete this->section_headers;
+ if (this->section_names != NULL)
+ delete this->section_names;
+ if (this->symbols != NULL)
+ delete this->symbols;
+ if (this->symbol_names != NULL)
+ delete this->symbol_names;
+ if (this->versym != NULL)
+ delete this->versym;
+ if (this->verdef != NULL)
+ delete this->verdef;
+ if (this->verneed != NULL)
+ delete this->verneed;
+}
+
// Class Xindex.
// Initialize the symtab_xindex_ array. Find the SHT_SYMTAB_SHNDX
return false;
}
+// If NAME is the name of the special section which indicates that
+// this object was compiled with -fstack-split, mark it accordingly.
+
+bool
+Object::handle_split_stack_section(const char* name)
+{
+ if (strcmp(name, ".note.GNU-split-stack") == 0)
+ {
+ this->uses_split_stack_ = true;
+ return true;
+ }
+ if (strcmp(name, ".note.GNU-no-split-stack") == 0)
+ {
+ this->has_no_split_stack_ = true;
+ return true;
+ }
+ return false;
+}
+
// Class Relobj
// To copy the symbols data read from the file to a local data structure.
&& strstr(name, "personality"))
|| (is_prefix_of(".data", name)
&& strstr(name, "personality"))
- || (is_prefix_of(".gnu.linkonce.d", name) &&
- strstr(name, "personality")))
+ || (is_prefix_of(".gnu.linkonce.d", name)
+ && strstr(name, "personality")))
{
return true;
}
}
// Set up an object file based on the file header. This sets up the
-// target and reads the section information.
+// section information.
template<int size, bool big_endian>
void
-Sized_relobj<size, big_endian>::setup(Target *target)
+Sized_relobj<size, big_endian>::do_setup()
{
- this->set_target(target);
-
const unsigned int shnum = this->elf_file_.shnum();
this->set_shnum(shnum);
}
const unsigned int shnum = this->shnum();
bool is_gc_pass_one = ((parameters->options().gc_sections()
&& !symtab->gc()->is_worklist_ready())
- || (parameters->options().icf()
+ || (parameters->options().icf_enabled()
&& !symtab->icf()->is_icf_ready()));
bool is_gc_pass_two = ((parameters->options().gc_sections()
&& symtab->gc()->is_worklist_ready())
- || (parameters->options().icf()
+ || (parameters->options().icf_enabled()
&& symtab->icf()->is_icf_ready()));
bool is_gc_or_icf = (parameters->options().gc_sections()
- || parameters->options().icf());
+ || parameters->options().icf_enabled());
// Both is_gc_pass_one and is_gc_pass_two should not be true.
gold_assert(!(is_gc_pass_one && is_gc_pass_two));
omit[i] = true;
}
+ // The .note.GNU-split-stack section is also special. It
+ // indicates that the object was compiled with
+ // -fsplit-stack.
+ if (this->handle_split_stack_section(name))
+ {
+ if (!parameters->options().relocatable()
+ && !parameters->options().shared())
+ omit[i] = true;
+ }
+
+ // Skip attributes section.
+ if (parameters->target().is_attributes_section(name))
+ {
+ omit[i] = true;
+ }
+
bool discard = omit[i];
if (!discard)
{
{
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
}
}
- if (is_gc_pass_two && parameters->options().icf())
+ if (is_gc_pass_two && parameters->options().icf_enabled())
{
if (out_sections[i] == NULL)
{
}
}
- if (!is_gc_pass_one)
+ if (!is_gc_pass_two)
layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
// When doing a relocatable link handle the reloc sections at the
}
Output_section* data_section = out_sections[data_shndx];
+ if (data_section == reinterpret_cast<Output_section*>(2))
+ {
+ // The layout for the data section was deferred, so we need
+ // to defer the relocation section, too.
+ const char* name = pnames + shdr.get_sh_name();
+ this->deferred_layout_relocs_.push_back(
+ Deferred_layout(i, name, pshdr, 0, elfcpp::SHT_NULL));
+ out_sections[i] = reinterpret_cast<Output_section*>(2);
+ out_section_offsets[i] = invalid_address;
+ continue;
+ }
if (data_section == NULL)
{
out_sections[i] = NULL;
reloc_type[i],
&offset);
out_sections[i] = os;
- if (offset == -1)
+ if (os == NULL || offset == -1)
{
// An object can contain at most one section holding exception
// frame information.
// If this section requires special handling, and if there are
// relocs that apply to it, then we must do the special handling
// before we apply the relocs.
- if (offset == -1 && reloc_shndx[i] != 0)
+ if (os != NULL && offset == -1 && reloc_shndx[i] != 0)
this->set_relocs_must_follow_section_writes();
}
++deferred)
{
typename This::Shdr shdr(deferred->shdr_data_);
+ // If the section is not included, it is because the garbage collector
+ // decided it is not needed. Avoid reverting that decision.
+ if (!this->is_section_included(deferred->shndx_))
+ continue;
+
this->layout_section(layout, deferred->shndx_, deferred->name_.c_str(),
shdr, deferred->reloc_shndx_, deferred->reloc_type_);
}
this->deferred_layout_.clear();
+
+ // Now handle the deferred relocation sections.
+
+ Output_sections& out_sections(this->output_sections());
+ std::vector<Address>& out_section_offsets(this->section_offsets_);
+
+ for (deferred = this->deferred_layout_relocs_.begin();
+ deferred != this->deferred_layout_relocs_.end();
+ ++deferred)
+ {
+ unsigned int shndx = deferred->shndx_;
+ typename This::Shdr shdr(deferred->shdr_data_);
+ unsigned int data_shndx = this->adjust_shndx(shdr.get_sh_info());
+
+ Output_section* data_section = out_sections[data_shndx];
+ if (data_section == NULL)
+ {
+ out_sections[shndx] = NULL;
+ out_section_offsets[shndx] = invalid_address;
+ continue;
+ }
+
+ Relocatable_relocs* rr = new Relocatable_relocs();
+ this->set_relocatable_relocs(shndx, rr);
+
+ Output_section* os = layout->layout_reloc(this, shndx, shdr,
+ data_section, rr);
+ out_sections[shndx] = os;
+ out_section_offsets[shndx] = invalid_address;
+ }
}
// Add the symbols to the symbol table.
sd->symbol_names = NULL;
}
+// Find out if this object, that is a member of a lib group, should be included
+// in the link. We check every symbol defined by this object. If the symbol
+// table has a strong undefined reference to that symbol, we have to include
+// the object.
+
+template<int size, bool big_endian>
+Archive::Should_include
+Sized_relobj<size, big_endian>::do_should_include_member(Symbol_table* symtab,
+ Read_symbols_data* sd,
+ std::string* why)
+{
+ char* tmpbuf = NULL;
+ size_t tmpbuflen = 0;
+ const char* sym_names =
+ reinterpret_cast<const char*>(sd->symbol_names->data());
+ const unsigned char* syms =
+ sd->symbols->data() + sd->external_symbols_offset;
+ const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
+ size_t symcount = ((sd->symbols_size - sd->external_symbols_offset)
+ / sym_size);
+
+ const unsigned char* p = syms;
+
+ for (size_t i = 0; i < symcount; ++i, p += sym_size)
+ {
+ elfcpp::Sym<size, big_endian> sym(p);
+ unsigned int st_shndx = sym.get_st_shndx();
+ if (st_shndx == elfcpp::SHN_UNDEF)
+ continue;
+
+ unsigned int st_name = sym.get_st_name();
+ const char* name = sym_names + st_name;
+ Symbol* symbol;
+ Archive::Should_include t = Archive::should_include_member(symtab, name,
+ &symbol, why,
+ &tmpbuf,
+ &tmpbuflen);
+ if (t == Archive::SHOULD_INCLUDE_YES)
+ {
+ if (tmpbuf != NULL)
+ free(tmpbuf);
+ return t;
+ }
+ }
+ if (tmpbuf != NULL)
+ free(tmpbuf);
+ return Archive::SHOULD_INCLUDE_UNKNOWN;
+}
+
// First pass over the local symbols. Here we add their names to
// *POOL and *DYNPOOL, and we store the symbol value in
// THIS->LOCAL_VALUES_. This function is always called from a
unsigned int dyncount = 0;
// Skip the first, dummy, symbol.
psyms += sym_size;
+ bool discard_all = parameters->options().discard_all();
bool discard_locals = parameters->options().discard_locals();
for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
{
// Decide whether this symbol should go into the output file.
if ((shndx < shnum && out_sections[shndx] == NULL)
- || (shndx == this->discarded_eh_frame_shndx_))
+ || shndx == this->discarded_eh_frame_shndx_)
{
lv.set_no_output_symtab_entry();
gold_assert(!lv.needs_output_dynsym_entry());
continue;
}
+ const char* name = pnames + sym.get_st_name();
+
+ // If needed, add the symbol to the dynamic symbol table string pool.
+ if (lv.needs_output_dynsym_entry())
+ {
+ dynpool->add(name, true, NULL);
+ ++dyncount;
+ }
+
+ if (discard_all && lv.may_be_discarded_from_output_symtab())
+ {
+ lv.set_no_output_symtab_entry();
+ continue;
+ }
+
// If --discard-locals option is used, discard all temporary local
// symbols. These symbols start with system-specific local label
// prefixes, typically .L for ELF system. We want to be compatible
// - the symbol has a name.
//
// We do not discard a symbol if it needs a dynamic symbol entry.
- const char* name = pnames + sym.get_st_name();
if (discard_locals
&& sym.get_st_type() != elfcpp::STT_FILE
&& !lv.needs_output_dynsym_entry()
+ && lv.may_be_discarded_from_output_symtab()
&& parameters->target().is_local_label_name(name))
{
lv.set_no_output_symtab_entry();
continue;
}
+ // Discard the local symbol if -retain_symbols_file is specified
+ // and the local symbol is not in that file.
+ if (!parameters->options().should_retain_symbol(name))
+ {
+ lv.set_no_output_symtab_entry();
+ continue;
+ }
+
// Add the symbol to the symbol table string pool.
pool->add(name, true, NULL);
++count;
-
- // If needed, add the symbol to the dynamic symbol table string pool.
- if (lv.needs_output_dynsym_entry())
- {
- dynpool->add(name, true, NULL);
- ++dyncount;
- }
}
this->output_local_symbol_count_ = count;
os = folded_obj->output_section(folded.second);
gold_assert(os != NULL);
secoffset = folded_obj->get_output_section_offset(folded.second);
- gold_assert(secoffset != invalid_address);
+
+ // This could be a relaxed input section.
+ if (secoffset == invalid_address)
+ {
+ const Output_relaxed_input_section* relaxed_section =
+ os->find_relaxed_input_section(folded_obj, folded.second);
+ gold_assert(relaxed_section != NULL);
+ secoffset = relaxed_section->address() - os->address();
+ }
}
if (os == NULL)
}
else if (!os->find_starting_output_address(this, shndx, &start))
{
- // This is a section symbol, but apparently not one
- // in a merged section. Just use the start of the
- // output section. This happens with relocatable
- // links when the input object has section symbols
- // for arbitrary non-merge sections.
- lv.set_output_value(os->address());
+ // This is a section symbol, but apparently not one in a
+ // merged section. First check to see if this is a relaxed
+ // input section. If so, use its address. Otherwise just
+ // use the start of the output section. This happens with
+ // relocatable links when the input object has section
+ // symbols for arbitrary non-merge sections.
+ const Output_section_data* posd =
+ os->find_relaxed_input_section(this, shndx);
+ if (posd != NULL)
+ {
+ Address relocatable_link_adjustment =
+ relocatable ? os->address() : 0;
+ lv.set_output_value(posd->address()
+ - relocatable_link_adjustment);
+ }
+ else
+ lv.set_output_value(os->address());
}
else
{
// We have to consider the addend to determine the
// value to use in a relocation. START is the start
- // of this input section.
+ // of this input section. If we are doing a relocatable
+ // link, use offset from start output section instead of
+ // address.
+ Address adjusted_start =
+ relocatable ? start - os->address() : start;
Merged_symbol_value<size>* msv =
- new Merged_symbol_value<size>(lv.input_value(), start);
+ new Merged_symbol_value<size>(lv.input_value(),
+ adjusted_start);
lv.set_merged_symbol_value(msv);
}
}
+ lv.input_value());
}
- if (lv.needs_output_symtab_entry())
+ if (!lv.is_output_symtab_index_set())
{
lv.set_output_symtab_index(index);
++index;
st_shndx = out_sections[st_shndx]->out_shndx();
if (st_shndx >= elfcpp::SHN_LORESERVE)
{
- if (lv.needs_output_symtab_entry() && !strip_all)
+ if (lv.has_output_symtab_entry())
symtab_xindex->add(lv.output_symtab_index(), st_shndx);
- if (lv.needs_output_dynsym_entry())
+ if (lv.has_output_dynsym_entry())
dynsym_xindex->add(lv.output_dynsym_index(), st_shndx);
st_shndx = elfcpp::SHN_XINDEX;
}
}
// Write the symbol to the output symbol table.
- if (!strip_all && lv.needs_output_symtab_entry())
+ if (lv.has_output_symtab_entry())
{
elfcpp::Sym_write<size, big_endian> osym(ov);
}
// Write the symbol to the output dynamic symbol table.
- if (lv.needs_output_dynsym_entry())
+ if (lv.has_output_dynsym_entry())
{
gold_assert(dyn_ov < dyn_oview + dyn_output_size);
elfcpp::Sym_write<size, big_endian> osym(dyn_ov);
bool
Input_objects::add_object(Object* obj)
{
- // Set the global target from the first object file we recognize.
- Target* target = obj->target();
- if (!parameters->target_valid())
- set_parameters_target(target);
- else if (target != ¶meters->target())
- {
- obj->error(_("incompatible target"));
- return false;
- }
-
// Print the filename if the -t/--trace option is selected.
if (parameters->options().trace())
gold_info("%s", obj->name().c_str());
}
// Add this object to the cross-referencer if requested.
- if (parameters->options().user_set_print_symbol_counts())
+ if (parameters->options().user_set_print_symbol_counts()
+ || parameters->options().cref())
{
if (this->cref_ == NULL)
this->cref_ = new Cref();
void
Input_objects::check_dynamic_dependencies() const
{
+ bool issued_copy_dt_needed_error = false;
for (Dynobj_list::const_iterator p = this->dynobj_list_.begin();
p != this->dynobj_list_.end();
++p)
{
const Dynobj::Needed& needed((*p)->needed());
bool found_all = true;
- for (Dynobj::Needed::const_iterator pneeded = needed.begin();
- pneeded != needed.end();
- ++pneeded)
+ Dynobj::Needed::const_iterator pneeded;
+ for (pneeded = needed.begin(); pneeded != needed.end(); ++pneeded)
{
if (this->sonames_.find(*pneeded) == this->sonames_.end())
{
}
}
(*p)->set_has_unknown_needed_entries(!found_all);
+
+ // --copy-dt-needed-entries aka --add-needed is a GNU ld option
+ // that gold does not support. However, they cause no trouble
+ // unless there is a DT_NEEDED entry that we don't know about;
+ // warn only in that case.
+ if (!found_all
+ && !issued_copy_dt_needed_error
+ && (parameters->options().copy_dt_needed_entries()
+ || parameters->options().add_needed()))
+ {
+ const char* optname;
+ if (parameters->options().copy_dt_needed_entries())
+ optname = "--copy-dt-needed-entries";
+ else
+ optname = "--add-needed";
+ gold_error(_("%s is not supported but is required for %s in %s"),
+ optname, (*pneeded).c_str(), (*p)->name().c_str());
+ issued_copy_dt_needed_error = true;
+ }
}
}
void
Input_objects::archive_start(Archive* archive)
{
- if (parameters->options().user_set_print_symbol_counts())
+ if (parameters->options().user_set_print_symbol_counts()
+ || parameters->options().cref())
{
if (this->cref_ == NULL)
this->cref_ = new Cref();
void
Input_objects::archive_stop(Archive* archive)
{
- if (parameters->options().user_set_print_symbol_counts())
+ if (parameters->options().user_set_print_symbol_counts()
+ || parameters->options().cref())
this->cref_->add_archive_stop(archive);
}
this->cref_->print_symbol_counts(symtab);
}
+// Print a cross reference table.
+
+void
+Input_objects::print_cref(const Symbol_table* symtab, FILE* f) const
+{
+ if (parameters->options().cref() && this->cref_ != NULL)
+ this->cref_->print_cref(symtab, f);
+}
+
// Relocate_info methods.
// Return a string describing the location of a relocation. This is
template<int size, bool big_endian>
Object*
make_elf_sized_object(const std::string& name, Input_file* input_file,
- off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
+ off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr,
+ bool* punconfigured)
{
Target* target = select_target(ehdr.get_e_machine(), size, big_endian,
ehdr.get_e_ident()[elfcpp::EI_OSABI],
if (target == NULL)
gold_fatal(_("%s: unsupported ELF machine number %d"),
name.c_str(), ehdr.get_e_machine());
+
+ if (!parameters->target_valid())
+ set_parameters_target(target);
+ else if (target != ¶meters->target())
+ {
+ if (punconfigured != NULL)
+ *punconfigured = true;
+ else
+ gold_error(_("%s: incompatible target"), name.c_str());
+ return NULL;
+ }
+
return target->make_elf_object<size, big_endian>(name, input_file, offset,
ehdr);
}
const unsigned char** start, int *read_size)
{
off_t filesize = input_file->file().filesize();
- int want = elfcpp::Elf_sizes<64>::ehdr_size;
+ int want = elfcpp::Elf_recognizer::max_header_size;
if (filesize - offset < want)
want = filesize - offset;
*start = p;
*read_size = want;
- if (want < 4)
- return false;
-
- static unsigned char elfmagic[4] =
- {
- elfcpp::ELFMAG0, elfcpp::ELFMAG1,
- elfcpp::ELFMAG2, elfcpp::ELFMAG3
- };
- return memcmp(p, elfmagic, 4) == 0;
+ return elfcpp::Elf_recognizer::is_elf_file(p, want);
}
// Read an ELF file and return the appropriate instance of Object.
if (punconfigured != NULL)
*punconfigured = false;
- if (bytes < elfcpp::EI_NIDENT)
- {
- gold_error(_("%s: ELF file too short"), name.c_str());
- return NULL;
- }
-
- int v = p[elfcpp::EI_VERSION];
- if (v != elfcpp::EV_CURRENT)
- {
- if (v == elfcpp::EV_NONE)
- gold_error(_("%s: invalid ELF version 0"), name.c_str());
- else
- gold_error(_("%s: unsupported ELF version %d"), name.c_str(), v);
- return NULL;
- }
-
- int c = p[elfcpp::EI_CLASS];
- if (c == elfcpp::ELFCLASSNONE)
- {
- gold_error(_("%s: invalid ELF class 0"), name.c_str());
- return NULL;
- }
- else if (c != elfcpp::ELFCLASS32
- && c != elfcpp::ELFCLASS64)
- {
- gold_error(_("%s: unsupported ELF class %d"), name.c_str(), c);
- return NULL;
- }
-
- int d = p[elfcpp::EI_DATA];
- if (d == elfcpp::ELFDATANONE)
- {
- gold_error(_("%s: invalid ELF data encoding"), name.c_str());
- return NULL;
- }
- else if (d != elfcpp::ELFDATA2LSB
- && d != elfcpp::ELFDATA2MSB)
+ std::string error;
+ bool big_endian = false;
+ int size = 0;
+ if (!elfcpp::Elf_recognizer::is_valid_header(p, bytes, &size,
+ &big_endian, &error))
{
- gold_error(_("%s: unsupported ELF data encoding %d"), name.c_str(), d);
+ gold_error(_("%s: %s"), name.c_str(), error.c_str());
return NULL;
}
- bool big_endian = d == elfcpp::ELFDATA2MSB;
-
- if (c == elfcpp::ELFCLASS32)
+ if (size == 32)
{
- if (bytes < elfcpp::Elf_sizes<32>::ehdr_size)
- {
- gold_error(_("%s: ELF file too short"), name.c_str());
- return NULL;
- }
if (big_endian)
{
#ifdef HAVE_TARGET_32_BIG
elfcpp::Ehdr<32, true> ehdr(p);
return make_elf_sized_object<32, true>(name, input_file,
- offset, ehdr);
+ offset, ehdr, punconfigured);
#else
if (punconfigured != NULL)
*punconfigured = true;
#ifdef HAVE_TARGET_32_LITTLE
elfcpp::Ehdr<32, false> ehdr(p);
return make_elf_sized_object<32, false>(name, input_file,
- offset, ehdr);
+ offset, ehdr, punconfigured);
#else
if (punconfigured != NULL)
*punconfigured = true;
#endif
}
}
- else
+ else if (size == 64)
{
- if (bytes < elfcpp::Elf_sizes<64>::ehdr_size)
- {
- gold_error(_("%s: ELF file too short"), name.c_str());
- return NULL;
- }
if (big_endian)
{
#ifdef HAVE_TARGET_64_BIG
elfcpp::Ehdr<64, true> ehdr(p);
return make_elf_sized_object<64, true>(name, input_file,
- offset, ehdr);
+ offset, ehdr, punconfigured);
#else
if (punconfigured != NULL)
*punconfigured = true;
#ifdef HAVE_TARGET_64_LITTLE
elfcpp::Ehdr<64, false> ehdr(p);
return make_elf_sized_object<64, false>(name, input_file,
- offset, ehdr);
+ offset, ehdr, punconfigured);
#else
if (punconfigured != NULL)
*punconfigured = true;
#endif
}
}
+ else
+ gold_unreachable();
}
// Instantiate the templates we need.
struct Relocate_info<64, true>;
#endif
+#ifdef HAVE_TARGET_32_LITTLE
+template
+void
+Xindex::initialize_symtab_xindex<32, false>(Object*, unsigned int);
+
+template
+void
+Xindex::read_symtab_xindex<32, false>(Object*, unsigned int,
+ const unsigned char*);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+void
+Xindex::initialize_symtab_xindex<32, true>(Object*, unsigned int);
+
+template
+void
+Xindex::read_symtab_xindex<32, true>(Object*, unsigned int,
+ const unsigned char*);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+void
+Xindex::initialize_symtab_xindex<64, false>(Object*, unsigned int);
+
+template
+void
+Xindex::read_symtab_xindex<64, false>(Object*, unsigned int,
+ const unsigned char*);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+void
+Xindex::initialize_symtab_xindex<64, true>(Object*, unsigned int);
+
+template
+void
+Xindex::read_symtab_xindex<64, true>(Object*, unsigned int,
+ const unsigned char*);
+#endif
+
} // End namespace gold.