// symtab.cc -- the gold symbol table
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "gold.h"
#include <stdint.h>
+#include <set>
#include <string>
#include <utility>
+#include "demangle.h"
#include "object.h"
+#include "dwarf_reader.h"
#include "dynobj.h"
#include "output.h"
#include "target.h"
this->has_got_offset_ = false;
this->has_plt_offset_ = false;
this->has_warning_ = false;
+ this->is_copied_from_dynobj_ = false;
+}
+
+// Return the demangled version of the symbol's name, but only
+// if the --demangle flag was set.
+
+static std::string
+demangle(const char* name)
+{
+ if (!parameters->demangle())
+ return name;
+
+ // cplus_demangle allocates memory for the result it returns,
+ // and returns NULL if the name is already demangled.
+ char* demangled_name = cplus_demangle(name, DMGL_ANSI | DMGL_PARAMS);
+ if (demangled_name == NULL)
+ return name;
+
+ std::string retval(demangled_name);
+ free(demangled_name);
+ return retval;
+}
+
+std::string
+Symbol::demangled_name() const
+{
+ return demangle(this->name());
}
// Initialize the fields in the base class Symbol for SYM in OBJECT.
this->in_reg_ = true;
}
+// Allocate a common symbol in the base.
+
+void
+Symbol::allocate_base_common(Output_data* od)
+{
+ gold_assert(this->is_common());
+ this->source_ = IN_OUTPUT_DATA;
+ this->u_.in_output_data.output_data = od;
+ this->u_.in_output_data.offset_is_from_end = false;
+}
+
// Initialize the fields in Sized_symbol for SYM in OBJECT.
template<int size>
this->symsize_ = symsize;
}
+// Allocate a common symbol.
+
+template<int size>
+void
+Sized_symbol<size>::allocate_common(Output_data* od, Value_type value)
+{
+ this->allocate_base_common(od);
+ this->value_ = value;
+}
+
// Return true if this symbol should be added to the dynamic symbol
// table.
// Class Symbol_table.
-Symbol_table::Symbol_table()
- : saw_undefined_(0), offset_(0), table_(), namepool_(),
+Symbol_table::Symbol_table(unsigned int count)
+ : saw_undefined_(0), offset_(0), table_(count), namepool_(),
forwarders_(), commons_(), warnings_()
{
+ namepool_.reserve(count);
}
Symbol_table::~Symbol_table()
{
}
-// The hash function. The key is always canonicalized, so we use a
-// simple combination of the pointers.
+// The hash function. The key values are Stringpool keys.
-size_t
+inline size_t
Symbol_table::Symbol_table_hash::operator()(const Symbol_table_key& key) const
{
return key.first ^ key.second;
}
-// The symbol table key equality function. This is only called with
-// canonicalized name and version strings, so we can use pointer
-// comparison.
+// The symbol table key equality function. This is called with
+// Stringpool keys.
-bool
+inline bool
Symbol_table::Symbol_table_eq::operator()(const Symbol_table_key& k1,
const Symbol_table_key& k2) const
{
return k1.first == k2.first && k1.second == k2.second;
}
-// Make TO a symbol which forwards to FROM.
+// Make TO a symbol which forwards to FROM.
void
Symbol_table::make_forwarder(Symbol* from, Symbol* to)
esym.put_st_info(from->binding(), from->type());
esym.put_st_other(from->visibility(), from->nonvis());
esym.put_st_shndx(from->shndx());
- this->resolve(to, esym.sym(), from->object(), version);
+ this->resolve(to, esym.sym(), esym.sym(), from->object(), version);
if (from->in_reg())
to->set_in_reg();
if (from->in_dyn())
// object file as a forwarder, and record it in the forwarders_ map.
// Note that entries in the hash table will never be marked as
// forwarders.
+//
+// SYM and ORIG_SYM are almost always the same. ORIG_SYM is the
+// symbol exactly as it existed in the input file. SYM is usually
+// that as well, but can be modified, for instance if we determine
+// it's in a to-be-discarded section.
template<int size, bool big_endian>
Sized_symbol<size>*
const char *version,
Stringpool::Key version_key,
bool def,
- const elfcpp::Sym<size, big_endian>& sym)
+ const elfcpp::Sym<size, big_endian>& sym,
+ const elfcpp::Sym<size, big_endian>& orig_sym)
{
Symbol* const snull = NULL;
std::pair<typename Symbol_table_type::iterator, bool> ins =
was_undefined = ret->is_undefined();
was_common = ret->is_common();
- this->resolve(ret, sym, object, version);
+ this->resolve(ret, sym, orig_sym, object, version);
if (def)
{
// NAME/NULL point to NAME/VERSION.
insdef.first->second = ret;
}
- else if (insdef.first->second != ret)
+ else if (insdef.first->second != ret
+ && insdef.first->second->is_undefined())
{
// This is the unfortunate case where we already have
- // entries for both NAME/VERSION and NAME/NULL.
+ // entries for both NAME/VERSION and NAME/NULL. Note
+ // that we don't want to combine them if the existing
+ // symbol is going to override the new one. FIXME: We
+ // currently just test is_undefined, but this may not do
+ // the right thing if the existing symbol is from a
+ // shared library and the new one is from a regular
+ // object.
+
const Sized_symbol<size>* sym2;
sym2 = this->get_sized_symbol SELECT_SIZE_NAME(size) (
insdef.first->second
ret = this->get_sized_symbol SELECT_SIZE_NAME(size) (
insdef.first->second
SELECT_SIZE(size));
- this->resolve(ret, sym, object, version);
+ this->resolve(ret, sym, orig_sym, object, version);
ins.first->second = ret;
}
else
size_t count,
const char* sym_names,
size_t sym_name_size,
- Symbol** sympointers)
+ typename Sized_relobj<size, big_endian>::Symbols* sympointers)
{
gold_assert(size == relobj->target()->get_size());
gold_assert(size == parameters->get_size());
Stringpool::Key name_key;
name = this->namepool_.add(name, true, &name_key);
res = this->add_from_object(relobj, name, name_key, NULL, 0,
- false, *psym);
+ false, *psym, sym);
}
else
{
Stringpool::Key name_key;
- name = this->namepool_.add_prefix(name, ver - name, &name_key);
+ name = this->namepool_.add_with_length(name, ver - name, true,
+ &name_key);
bool def = false;
++ver;
ver = this->namepool_.add(ver, true, &ver_key);
res = this->add_from_object(relobj, name, name_key, ver, ver_key,
- def, *psym);
+ def, *psym, sym);
}
- *sympointers++ = res;
+ (*sympointers)[i] = res;
}
}
Stringpool::Key name_key;
name = this->namepool_.add(name, true, &name_key);
res = this->add_from_object(dynobj, name, name_key, NULL, 0,
- false, sym);
+ false, sym, sym);
}
else
{
{
// This symbol does not have a version.
res = this->add_from_object(dynobj, name, name_key, NULL, 0,
- false, sym);
+ false, sym, sym);
}
else
{
if (sym.get_st_shndx() == elfcpp::SHN_ABS
&& name_key == version_key)
res = this->add_from_object(dynobj, name, name_key, NULL, 0,
- false, sym);
+ false, sym, sym);
else
{
const bool def = (!hidden
&& (sym.get_st_shndx()
!= elfcpp::SHN_UNDEF));
res = this->add_from_object(dynobj, name, name_key, version,
- version_key, def, sym);
+ version_key, def, sym, sym);
}
}
}
sym->init(name, od, value, symsize, type, binding, visibility, nonvis,
offset_is_from_end);
- if (oldsym != NULL
- && Symbol_table::should_override_with_special(oldsym))
- this->override_with_special(oldsym, sym);
+ if (oldsym == NULL)
+ return sym;
- return sym;
+ if (Symbol_table::should_override_with_special(oldsym))
+ this->override_with_special(oldsym, sym);
+ delete sym;
+ return oldsym;
}
// Define a symbol based on an Output_segment.
sym->init(name, os, value, symsize, type, binding, visibility, nonvis,
offset_base);
- if (oldsym != NULL
- && Symbol_table::should_override_with_special(oldsym))
- this->override_with_special(oldsym, sym);
+ if (oldsym == NULL)
+ return sym;
- return sym;
+ if (Symbol_table::should_override_with_special(oldsym))
+ this->override_with_special(oldsym, sym);
+ delete sym;
+ return oldsym;
}
// Define a special symbol with a constant value. It is a multiple
gold_assert(version == NULL || oldsym != NULL);
sym->init(name, value, symsize, type, binding, visibility, nonvis);
- if (oldsym != NULL
- && Symbol_table::should_override_with_special(oldsym))
- this->override_with_special(oldsym, sym);
+ if (oldsym == NULL)
+ return sym;
- return sym;
+ if (Symbol_table::should_override_with_special(oldsym))
+ this->override_with_special(oldsym, sym);
+ delete sym;
+ return oldsym;
}
// Define a set of symbols in output sections.
}
}
+// Define CSYM using a COPY reloc. POSD is the Output_data where the
+// symbol should be defined--typically a .dyn.bss section. VALUE is
+// the offset within POSD.
+
+template<int size>
+void
+Symbol_table::define_with_copy_reloc(
+ const Target* target,
+ Sized_symbol<size>* csym,
+ Output_data* posd,
+ typename elfcpp::Elf_types<size>::Elf_Addr value)
+{
+ gold_assert(csym->is_from_dynobj());
+ gold_assert(!csym->is_copied_from_dynobj());
+ Object* object = csym->object();
+ gold_assert(object->is_dynamic());
+ Dynobj* dynobj = static_cast<Dynobj*>(object);
+
+ // Our copied variable has to override any variable in a shared
+ // library.
+ elfcpp::STB binding = csym->binding();
+ if (binding == elfcpp::STB_WEAK)
+ binding = elfcpp::STB_GLOBAL;
+
+ this->define_in_output_data(target, csym->name(), csym->version(),
+ posd, value, csym->symsize(),
+ csym->type(), binding,
+ csym->visibility(), csym->nonvis(),
+ false, false);
+
+ csym->set_is_copied_from_dynobj();
+ csym->set_needs_dynsym_entry();
+
+ this->copied_symbol_dynobjs_[csym] = dynobj;
+
+ // We have now defined all aliases, but we have not entered them all
+ // in the copied_symbol_dynobjs_ map.
+ if (csym->has_alias())
+ {
+ Symbol* sym = csym;
+ while (true)
+ {
+ sym = this->weak_aliases_[sym];
+ if (sym == csym)
+ break;
+ gold_assert(sym->output_data() == posd);
+
+ sym->set_is_copied_from_dynobj();
+ this->copied_symbol_dynobjs_[sym] = dynobj;
+ }
+ }
+}
+
+// SYM is defined using a COPY reloc. Return the dynamic object where
+// the original definition was found.
+
+Dynobj*
+Symbol_table::get_copy_source(const Symbol* sym) const
+{
+ gold_assert(sym->is_copied_from_dynobj());
+ Copied_symbol_dynobjs::const_iterator p =
+ this->copied_symbol_dynobjs_.find(sym);
+ gold_assert(p != this->copied_symbol_dynobjs_.end());
+ return p->second;
+}
+
// Set the dynamic symbol indexes. INDEX is the index of the first
// global dynamic symbol. Pointers to the symbols are stored into the
// vector SYMS. The names are added to DYNPOOL. This returns an
// updated dynamic symbol index.
unsigned int
-Symbol_table::set_dynsym_indexes(const General_options* options,
- const Target* target,
+Symbol_table::set_dynsym_indexes(const Target* target,
unsigned int index,
std::vector<Symbol*>* syms,
Stringpool* dynpool,
// Record any version information.
if (sym->version() != NULL)
- versions->record_version(options, dynpool, sym);
+ versions->record_version(this, dynpool, sym);
}
}
&& shndx != elfcpp::SHN_ABS)
{
gold_error(_("%s: unsupported symbol section 0x%x"),
- sym->name(), shndx);
+ sym->demangled_name().c_str(), shndx);
shndx = elfcpp::SHN_UNDEF;
}
else
{
Relobj* relobj = static_cast<Relobj*>(symobj);
- off_t secoff;
+ section_offset_type secoff;
Output_section* os = relobj->output_section(shndx, &secoff);
if (os == NULL)
continue;
}
- value = sym->value() + os->address() + secoff;
+ if (sym->type() == elfcpp::STT_TLS)
+ value = sym->value() + os->tls_offset() + secoff;
+ else
+ value = sym->value() + os->address() + secoff;
}
}
break;
// Write out the global symbols.
void
-Symbol_table::write_globals(const Target* target, const Stringpool* sympool,
+Symbol_table::write_globals(const Input_objects* input_objects,
+ const Stringpool* sympool,
const Stringpool* dynpool, Output_file* of) const
{
if (parameters->get_size() == 32)
if (parameters->is_big_endian())
{
#ifdef HAVE_TARGET_32_BIG
- this->sized_write_globals<32, true>(target, sympool, dynpool, of);
+ this->sized_write_globals<32, true>(input_objects, sympool,
+ dynpool, of);
#else
gold_unreachable();
#endif
else
{
#ifdef HAVE_TARGET_32_LITTLE
- this->sized_write_globals<32, false>(target, sympool, dynpool, of);
+ this->sized_write_globals<32, false>(input_objects, sympool,
+ dynpool, of);
#else
gold_unreachable();
#endif
if (parameters->is_big_endian())
{
#ifdef HAVE_TARGET_64_BIG
- this->sized_write_globals<64, true>(target, sympool, dynpool, of);
+ this->sized_write_globals<64, true>(input_objects, sympool,
+ dynpool, of);
#else
gold_unreachable();
#endif
else
{
#ifdef HAVE_TARGET_64_LITTLE
- this->sized_write_globals<64, false>(target, sympool, dynpool, of);
+ this->sized_write_globals<64, false>(input_objects, sympool,
+ dynpool, of);
#else
gold_unreachable();
#endif
template<int size, bool big_endian>
void
-Symbol_table::sized_write_globals(const Target* target,
+Symbol_table::sized_write_globals(const Input_objects* input_objects,
const Stringpool* sympool,
const Stringpool* dynpool,
Output_file* of) const
{
+ const Target* const target = input_objects->target();
+
const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
unsigned int index = this->first_global_index_;
const off_t oview_size = this->output_count_ * sym_size;
{
Sized_symbol<size>* sym = static_cast<Sized_symbol<size>*>(p->second);
+ // Possibly warn about unresolved symbols in shared libraries.
+ this->warn_about_undefined_dynobj_symbol(input_objects, sym);
+
unsigned int sym_index = sym->symtab_index();
unsigned int dynsym_index;
if (dynamic_view == NULL)
&& in_shndx != elfcpp::SHN_ABS)
{
gold_error(_("%s: unsupported symbol section 0x%x"),
- sym->name(), in_shndx);
+ sym->demangled_name().c_str(), in_shndx);
shndx = in_shndx;
}
else
else
{
Relobj* relobj = static_cast<Relobj*>(symobj);
- off_t secoff;
+ section_offset_type secoff;
Output_section* os = relobj->output_section(in_shndx,
&secoff);
gold_assert(os != NULL);
osym.put_st_shndx(shndx);
}
+// Check for unresolved symbols in shared libraries. This is
+// controlled by the --allow-shlib-undefined option.
+
+// We only warn about libraries for which we have seen all the
+// DT_NEEDED entries. We don't try to track down DT_NEEDED entries
+// which were not seen in this link. If we didn't see a DT_NEEDED
+// entry, we aren't going to be able to reliably report whether the
+// symbol is undefined.
+
+// We also don't warn about libraries found in the system library
+// directory (the directory were we find libc.so); we assume that
+// those libraries are OK. This heuristic avoids problems in
+// GNU/Linux, in which -ldl can have undefined references satisfied by
+// ld-linux.so.
+
+inline void
+Symbol_table::warn_about_undefined_dynobj_symbol(
+ const Input_objects* input_objects,
+ Symbol* sym) const
+{
+ if (sym->source() == Symbol::FROM_OBJECT
+ && sym->object()->is_dynamic()
+ && sym->shndx() == elfcpp::SHN_UNDEF
+ && sym->binding() != elfcpp::STB_WEAK
+ && !parameters->allow_shlib_undefined()
+ && !input_objects->target()->is_defined_by_abi(sym)
+ && !input_objects->found_in_system_library_directory(sym->object()))
+ {
+ // A very ugly cast.
+ Dynobj* dynobj = static_cast<Dynobj*>(sym->object());
+ if (!dynobj->has_unknown_needed_entries())
+ gold_error(_("%s: undefined reference to '%s'"),
+ sym->object()->name().c_str(),
+ sym->demangled_name().c_str());
+ }
+}
+
// Write out a section symbol. Return the update offset.
void
of->write_output_view(offset, sym_size, pov);
}
+// Print statistical information to stderr. This is used for --stats.
+
+void
+Symbol_table::print_stats() const
+{
+#if defined(HAVE_TR1_UNORDERED_MAP) || defined(HAVE_EXT_HASH_MAP)
+ fprintf(stderr, _("%s: symbol table entries: %zu; buckets: %zu\n"),
+ program_name, this->table_.size(), this->table_.bucket_count());
+#else
+ fprintf(stderr, _("%s: symbol table entries: %zu\n"),
+ program_name, this->table_.size());
+#endif
+ this->namepool_.print_stats("symbol table stringpool");
+}
+
+// We check for ODR violations by looking for symbols with the same
+// name for which the debugging information reports that they were
+// defined in different source locations. When comparing the source
+// location, we consider instances with the same base filename and
+// line number to be the same. This is because different object
+// files/shared libraries can include the same header file using
+// different paths, and we don't want to report an ODR violation in
+// that case.
+
+// This struct is used to compare line information, as returned by
+// Dwarf_line_info::one_addr2line. It implements a < comparison
+// operator used with std::set.
+
+struct Odr_violation_compare
+{
+ bool
+ operator()(const std::string& s1, const std::string& s2) const
+ {
+ std::string::size_type pos1 = s1.rfind('/');
+ std::string::size_type pos2 = s2.rfind('/');
+ if (pos1 == std::string::npos
+ || pos2 == std::string::npos)
+ return s1 < s2;
+ return s1.compare(pos1, std::string::npos,
+ s2, pos2, std::string::npos) < 0;
+ }
+};
+
+// Check candidate_odr_violations_ to find symbols with the same name
+// but apparently different definitions (different source-file/line-no).
+
+void
+Symbol_table::detect_odr_violations(const Task* task,
+ const char* output_file_name) const
+{
+ for (Odr_map::const_iterator it = candidate_odr_violations_.begin();
+ it != candidate_odr_violations_.end();
+ ++it)
+ {
+ const char* symbol_name = it->first;
+ // We use a sorted set so the output is deterministic.
+ std::set<std::string, Odr_violation_compare> line_nums;
+
+ for (Unordered_set<Symbol_location, Symbol_location_hash>::const_iterator
+ locs = it->second.begin();
+ locs != it->second.end();
+ ++locs)
+ {
+ // We need to lock the object in order to read it. This
+ // means that we have to run in a singleton Task. If we
+ // want to run this in a general Task for better
+ // performance, we will need one Task for object, plus
+ // appropriate locking to ensure that we don't conflict with
+ // other uses of the object.
+ Task_lock_obj<Object> tl(task, locs->object);
+ std::string lineno = Dwarf_line_info::one_addr2line(
+ locs->object, locs->shndx, locs->offset);
+ if (!lineno.empty())
+ line_nums.insert(lineno);
+ }
+
+ if (line_nums.size() > 1)
+ {
+ gold_warning(_("while linking %s: symbol '%s' defined in multiple "
+ "places (possible ODR violation):"),
+ output_file_name, demangle(symbol_name).c_str());
+ for (std::set<std::string>::const_iterator it2 = line_nums.begin();
+ it2 != line_nums.end();
+ ++it2)
+ fprintf(stderr, " %s\n", it2->c_str());
+ }
+ }
+}
+
// Warnings functions.
// Add a new warning.
void
Warnings::add_warning(Symbol_table* symtab, const char* name, Object* obj,
- unsigned int shndx)
+ const std::string& warning)
{
name = symtab->canonicalize_name(name);
- this->warnings_[name].set(obj, shndx);
+ this->warnings_[name].set(obj, warning);
}
// Look through the warnings and mark the symbols for which we should
if (sym != NULL
&& sym->source() == Symbol::FROM_OBJECT
&& sym->object() == p->second.object)
- {
- sym->set_has_warning();
-
- // Read the section contents to get the warning text. It
- // would be nicer if we only did this if we have to actually
- // issue a warning. Unfortunately, warnings are issued as
- // we relocate sections. That means that we can not lock
- // the object then, as we might try to issue the same
- // warning multiple times simultaneously.
- {
- Task_locker_obj<Object> tl(*p->second.object);
- const unsigned char* c;
- off_t len;
- c = p->second.object->section_contents(p->second.shndx, &len,
- false);
- p->second.set_text(reinterpret_cast<const char*>(c), len);
- }
- }
+ sym->set_has_warning();
}
}
// script to restrict this to only the ones needed for implemented
// targets.
+#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
+template
+void
+Sized_symbol<32>::allocate_common(Output_data*, Value_type);
+#endif
+
+#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
+template
+void
+Sized_symbol<64>::allocate_common(Output_data*, Value_type);
+#endif
+
#ifdef HAVE_TARGET_32_LITTLE
template
void
size_t count,
const char* sym_names,
size_t sym_name_size,
- Symbol** sympointers);
+ Sized_relobj<32, true>::Symbols* sympointers);
#endif
#ifdef HAVE_TARGET_32_BIG
size_t count,
const char* sym_names,
size_t sym_name_size,
- Symbol** sympointers);
+ Sized_relobj<32, false>::Symbols* sympointers);
#endif
#ifdef HAVE_TARGET_64_LITTLE
size_t count,
const char* sym_names,
size_t sym_name_size,
- Symbol** sympointers);
+ Sized_relobj<64, true>::Symbols* sympointers);
#endif
#ifdef HAVE_TARGET_64_BIG
size_t count,
const char* sym_names,
size_t sym_name_size,
- Symbol** sympointers);
+ Sized_relobj<64, false>::Symbols* sympointers);
#endif
#ifdef HAVE_TARGET_32_LITTLE
const std::vector<const char*>* version_map);
#endif
+#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
+template
+void
+Symbol_table::define_with_copy_reloc<32>(
+ const Target* target,
+ Sized_symbol<32>* sym,
+ Output_data* posd,
+ elfcpp::Elf_types<32>::Elf_Addr value);
+#endif
+
+#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
+template
+void
+Symbol_table::define_with_copy_reloc<64>(
+ const Target* target,
+ Sized_symbol<64>* sym,
+ Output_data* posd,
+ elfcpp::Elf_types<64>::Elf_Addr value);
+#endif
+
#ifdef HAVE_TARGET_32_LITTLE
template
void
size_t relnum, off_t reloffset) const;
#endif
-
} // End namespace gold.
projects / deliverable / binutils-gdb.git / blobdiff