// symtab.h -- the gold symbol table -*- 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.
#include <utility>
#include <vector>
+#include "gc.h"
#include "elfcpp.h"
#include "parameters.h"
#include "stringpool.h"
namespace gold
{
+class Mapfile;
class Object;
class Relobj;
template<int size, bool big_endian>
class Sized_relobj;
+template<int size, bool big_endian>
+class Sized_pluginobj;
class Dynobj;
template<int size, bool big_endian>
class Sized_dynobj;
class Output_segment;
class Output_file;
class Output_symtab_xindex;
+class Garbage_collection;
// The base class of an entry in the symbol table. The symbol table
// can have a lot of entries, so we don't want this class to big.
// section.
IN_OUTPUT_SEGMENT,
// Symbol value is constant.
- CONSTANT
+ IS_CONSTANT,
+ // Symbol is undefined.
+ IS_UNDEFINED
};
// When the source is IN_OUTPUT_SEGMENT, we need to describe what
visibility() const
{ return this->visibility_; }
+ // Set the visibility.
+ void
+ set_visibility(elfcpp::STV visibility)
+ { this->visibility_ = visibility; }
+
+ // Override symbol visibility.
+ void
+ override_visibility(elfcpp::STV);
+
// Return the non-visibility part of the st_other field.
unsigned char
nonvis() const
set_in_dyn()
{ this->in_dyn_ = true; }
+ // Return whether this symbol has been seen in a real ELF object.
+ // (IN_REG will return TRUE if the symbol has been seen in either
+ // a real ELF object or an object claimed by a plugin.)
+ bool
+ in_real_elf() const
+ { return this->in_real_elf_; }
+
+ // Mark this symbol as having been seen in a real ELF object.
+ void
+ set_in_real_elf()
+ { this->in_real_elf_ = true; }
+
// Return the index of this symbol in the output file symbol table.
// A value of -1U means that this symbol is not going into the
// output file. This starts out as zero, and is set to a non-zero
{
bool is_ordinary;
if (this->source_ != FROM_OBJECT)
- return true;
+ return this->source_ != IS_UNDEFINED;
unsigned int shndx = this->shndx(&is_ordinary);
return (is_ordinary
? shndx != elfcpp::SHN_UNDEF
is_undefined() const
{
bool is_ordinary;
- return (this->source_ == FROM_OBJECT
- && this->shndx(&is_ordinary) == elfcpp::SHN_UNDEF
- && is_ordinary);
+ return ((this->source_ == FROM_OBJECT
+ && this->shndx(&is_ordinary) == elfcpp::SHN_UNDEF
+ && is_ordinary)
+ || this->source_ == IS_UNDEFINED);
}
// Return whether this is a weak undefined symbol.
bool
is_weak_undefined() const
- {
- bool is_ordinary;
- return (this->source_ == FROM_OBJECT
- && this->binding() == elfcpp::STB_WEAK
- && this->shndx(&is_ordinary) == elfcpp::SHN_UNDEF
- && is_ordinary);
- }
+ { return this->is_undefined() && this->binding() == elfcpp::STB_WEAK; }
// Return whether this is an absolute symbol.
bool
is_absolute() const
{
bool is_ordinary;
- return (this->source_ == FROM_OBJECT
- && this->shndx(&is_ordinary) == elfcpp::SHN_ABS
- && !is_ordinary);
+ return ((this->source_ == FROM_OBJECT
+ && this->shndx(&is_ordinary) == elfcpp::SHN_ABS
+ && !is_ordinary)
+ || this->source_ == IS_CONSTANT);
}
// Return whether this is a common symbol.
bool
needs_plt_entry() const
{
+ // An undefined symbol from an executable does not need a PLT entry.
+ if (this->is_undefined() && !parameters->options().shared())
+ return false;
+
return (!parameters->doing_static_link()
&& this->type() == elfcpp::STT_FUNC
&& (this->is_from_dynobj()
if (parameters->doing_static_link())
return false;
- // A reference to a weak undefined symbol from an executable should be
+ // A reference to an undefined symbol from an executable should be
// statically resolved to 0, and does not need a dynamic relocation.
// This matches gnu ld behavior.
- if (this->is_weak_undefined() && !parameters->options().shared())
+ if (this->is_undefined() && !parameters->options().shared())
return false;
// A reference to an absolute symbol does not need a dynamic relocation.
return false;
}
+ // Whether we should use the PLT offset associated with a symbol for
+ // a relocation. IS_NON_PIC_REFERENCE is true if this is a non-PIC
+ // reloc--the same set of relocs for which we would pass NON_PIC_REF
+ // to the needs_dynamic_reloc function.
+
+ bool
+ use_plt_offset(bool is_non_pic_reference) const
+ {
+ // If the symbol doesn't have a PLT offset, then naturally we
+ // don't want to use it.
+ if (!this->has_plt_offset())
+ return false;
+
+ // If we are going to generate a dynamic relocation, then we will
+ // wind up using that, so no need to use the PLT entry.
+ if (this->needs_dynamic_reloc(FUNCTION_CALL
+ | (is_non_pic_reference
+ ? NON_PIC_REF
+ : 0)))
+ return false;
+
+ // If the symbol is from a dynamic object, we need to use the PLT
+ // entry.
+ if (this->is_from_dynobj())
+ return true;
+
+ // If we are generating a shared object, and this symbol is
+ // undefined or preemptible, we need to use the PLT entry.
+ if (parameters->options().shared()
+ && (this->is_undefined() || this->is_preemptible()))
+ return true;
+
+ // If this is a weak undefined symbol, we need to use the PLT
+ // entry; the symbol may be defined by a library loaded at
+ // runtime.
+ if (this->is_weak_undefined())
+ return true;
+
+ // Otherwise we can use the regular definition.
+ return false;
+ }
+
// Given a direct absolute static relocation against
// the global symbol, where a dynamic relocation is needed, this
// function returns whether a relative dynamic relocation can be used.
// index rather than a special code.
template<int size, bool big_endian>
void
- init_base(const char *name, const char* version, Object* object,
- const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
- bool is_ordinary);
+ init_base_object(const char *name, const char* version, Object* object,
+ const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
+ bool is_ordinary);
// Initialize fields for an Output_data.
void
- init_base(const char* name, Output_data*, elfcpp::STT, elfcpp::STB,
- elfcpp::STV, unsigned char nonvis, bool offset_is_from_end);
+ init_base_output_data(const char* name, const char* version, Output_data*,
+ elfcpp::STT, elfcpp::STB, elfcpp::STV,
+ unsigned char nonvis, bool offset_is_from_end);
// Initialize fields for an Output_segment.
void
- init_base(const char* name, Output_segment* os, elfcpp::STT type,
- elfcpp::STB binding, elfcpp::STV visibility,
- unsigned char nonvis, Segment_offset_base offset_base);
+ init_base_output_segment(const char* name, const char* version,
+ Output_segment* os, elfcpp::STT type,
+ elfcpp::STB binding, elfcpp::STV visibility,
+ unsigned char nonvis,
+ Segment_offset_base offset_base);
// Initialize fields for a constant.
void
- init_base(const char* name, elfcpp::STT type, elfcpp::STB binding,
- elfcpp::STV visibility, unsigned char nonvis);
+ init_base_constant(const char* name, const char* version, elfcpp::STT type,
+ elfcpp::STB binding, elfcpp::STV visibility,
+ unsigned char nonvis);
+
+ // Initialize fields for an undefined symbol.
+ void
+ init_base_undefined(const char* name, const char* version, elfcpp::STT type,
+ elfcpp::STB binding, elfcpp::STV visibility,
+ unsigned char nonvis);
// Override existing symbol.
template<int size, bool big_endian>
void
override_base_with_special(const Symbol* from);
+ // Override symbol version.
+ void
+ override_version(const char* version);
+
// Allocate a common symbol by giving it a location in the output
// file.
void
bool is_forced_local_ : 1;
// True if the field u_.from_object.shndx is an ordinary section
// index, not one of the special codes from SHN_LORESERVE to
- // SHN_HIRESERVE.
+ // SHN_HIRESERVE (bit 31).
bool is_ordinary_shndx_ : 1;
+ // True if we've seen this symbol in a real ELF object.
+ bool in_real_elf_ : 1;
};
// The parts of a symbol which are size specific. Using a template
// index rather than a special code.
template<bool big_endian>
void
- init(const char *name, const char* version, Object* object,
- const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
- bool is_ordinary);
+ init_object(const char *name, const char* version, Object* object,
+ const elfcpp::Sym<size, big_endian>&, unsigned int st_shndx,
+ bool is_ordinary);
// Initialize fields for an Output_data.
void
- init(const char* name, Output_data*, Value_type value, Size_type symsize,
- elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis,
- bool offset_is_from_end);
+ init_output_data(const char* name, const char* version, Output_data*,
+ Value_type value, Size_type symsize, elfcpp::STT,
+ elfcpp::STB, elfcpp::STV, unsigned char nonvis,
+ bool offset_is_from_end);
// Initialize fields for an Output_segment.
void
- init(const char* name, Output_segment*, Value_type value, Size_type symsize,
- elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis,
- Segment_offset_base offset_base);
+ init_output_segment(const char* name, const char* version, Output_segment*,
+ Value_type value, Size_type symsize, elfcpp::STT,
+ elfcpp::STB, elfcpp::STV, unsigned char nonvis,
+ Segment_offset_base offset_base);
// Initialize fields for a constant.
void
- init(const char* name, Value_type value, Size_type symsize,
- elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis);
+ init_constant(const char* name, const char* version, Value_type value,
+ Size_type symsize, elfcpp::STT, elfcpp::STB, elfcpp::STV,
+ unsigned char nonvis);
+
+ // Initialize fields for an undefined symbol.
+ void
+ init_undefined(const char* name, const char* version, elfcpp::STT,
+ elfcpp::STB, elfcpp::STV, unsigned char nonvis);
// Override existing symbol.
template<bool big_endian>
~Symbol_table();
+ void
+ set_gc(Garbage_collection* gc)
+ { this->gc_ = gc; }
+
+ Garbage_collection*
+ gc()
+ { return this->gc_; }
+
+ // During garbage collection, this keeps undefined symbols.
+ void
+ gc_mark_undef_symbols();
+
+ // During garbage collection, this ensures externally visible symbols
+ // are not treated as garbage while building shared objects.
+ void
+ gc_mark_symbol_for_shlib(Symbol* sym);
+
+ // During garbage collection, this keeps sections that correspond to
+ // symbols seen in dynamic objects.
+ inline void
+ gc_mark_dyn_syms(Symbol* sym);
+
// Add COUNT external symbols from the relocatable object RELOBJ to
// the symbol table. SYMS is the symbols, SYMNDX_OFFSET is the
// offset in the symbol table of the first symbol, SYM_NAMES is
// their names, SYM_NAME_SIZE is the size of SYM_NAMES. This sets
- // SYMPOINTERS to point to the symbols in the symbol table.
+ // SYMPOINTERS to point to the symbols in the symbol table. It sets
+ // *DEFINED to the number of defined symbols.
template<int size, bool big_endian>
void
add_from_relobj(Sized_relobj<size, big_endian>* relobj,
const unsigned char* syms, size_t count,
size_t symndx_offset, const char* sym_names,
size_t sym_name_size,
- typename Sized_relobj<size, big_endian>::Symbols*);
+ typename Sized_relobj<size, big_endian>::Symbols*,
+ size_t* defined);
+
+ // Add one external symbol from the plugin object OBJ to the symbol table.
+ // Returns a pointer to the resolved symbol in the symbol table.
+ template<int size, bool big_endian>
+ Symbol*
+ add_from_pluginobj(Sized_pluginobj<size, big_endian>* obj,
+ const char* name, const char* ver,
+ elfcpp::Sym<size, big_endian>* sym);
// Add COUNT dynamic symbols from the dynamic object DYNOBJ to the
// symbol table. SYMS is the symbols. SYM_NAMES is their names.
const unsigned char* syms, size_t count,
const char* sym_names, size_t sym_name_size,
const unsigned char* versym, size_t versym_size,
- const std::vector<const char*>*);
+ const std::vector<const char*>*,
+ typename Sized_relobj<size, big_endian>::Symbols*,
+ size_t* defined);
// Define a special symbol based on an Output_data. It is a
// multiple definition error if this symbol is already defined.
// Allocate the common symbols
void
- allocate_commons(Layout*);
+ allocate_commons(Layout*, Mapfile*);
// Add a warning for symbol NAME in object OBJ. WARNING is the text
// of the warning.
void
detect_odr_violations(const Task*, const char* output_file_name) const;
+ // Add any undefined symbols named on the command line to the symbol
+ // table.
+ void
+ add_undefined_symbols_from_command_line();
+
// SYM is defined using a COPY reloc. Return the dynamic object
// where the original definition was found.
Dynobj*
// Write out the global symbols.
void
- write_globals(const Input_objects*, const Stringpool*, const Stringpool*,
+ write_globals(const Stringpool*, const Stringpool*,
Output_symtab_xindex*, Output_symtab_xindex*,
Output_file*) const;
// The type of the list of common symbols.
typedef std::vector<Symbol*> Commons_type;
+ // The type of the symbol hash table.
+
+ typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key;
+
+ struct Symbol_table_hash
+ {
+ size_t
+ operator()(const Symbol_table_key&) const;
+ };
+
+ struct Symbol_table_eq
+ {
+ bool
+ operator()(const Symbol_table_key&, const Symbol_table_key&) const;
+ };
+
+ typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash,
+ Symbol_table_eq> Symbol_table_type;
+
// Make FROM a forwarder symbol to TO.
void
make_forwarder(Symbol* from, Symbol* to);
unsigned int st_shndx, bool is_ordinary,
unsigned int orig_st_shndx);
+ // Define a default symbol.
+ template<int size, bool big_endian>
+ void
+ define_default_version(Sized_symbol<size>*, bool,
+ Symbol_table_type::iterator);
+
// Resolve symbols.
template<int size, bool big_endian>
void
template<int size, bool big_endian>
void
- resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from,
- const char* version);
+ resolve(Sized_symbol<size>* to, const Sized_symbol<size>* from);
- // Record that a symbol is forced to be local by a version script.
+ // Record that a symbol is forced to be local by a version script or
+ // by visibility.
void
force_local(Symbol*);
template<int size, bool big_endian>
Sized_symbol<size>*
define_special_symbol(const char** pname, const char** pversion,
- bool only_if_ref, Sized_symbol<size>** poldsym);
+ bool only_if_ref, Sized_symbol<size>** poldsym,
+ bool* resolve_oldsym);
// Define a symbol in an Output_data, sized version.
template<int size>
elfcpp::STV visibility, unsigned char nonvis,
bool only_if_ref, bool force_override);
+ // Add any undefined symbols named on the command line to the symbol
+ // table, sized version.
+ template<int size>
+ void
+ do_add_undefined_symbols_from_command_line();
+
// Allocate the common symbols, sized version.
template<int size>
void
- do_allocate_commons(Layout*);
+ do_allocate_commons(Layout*, Mapfile*);
// Allocate the common symbols from one list.
template<int size>
void
- do_allocate_commons_list(Layout*, bool is_tls, Commons_type*);
+ do_allocate_commons_list(Layout*, bool is_tls, Commons_type*, Mapfile*);
// Implement detect_odr_violations.
template<int size, bool big_endian>
// Write globals specialized for size and endianness.
template<int size, bool big_endian>
void
- sized_write_globals(const Input_objects*, const Stringpool*,
- const Stringpool*, Output_symtab_xindex*,
- Output_symtab_xindex*, Output_file*) const;
+ sized_write_globals(const Stringpool*, const Stringpool*,
+ Output_symtab_xindex*, Output_symtab_xindex*,
+ Output_file*) const;
// Write out a symbol to P.
template<int size, bool big_endian>
// Possibly warn about an undefined symbol from a dynamic object.
void
- warn_about_undefined_dynobj_symbol(const Input_objects*, Symbol*) const;
+ warn_about_undefined_dynobj_symbol(Symbol*) const;
// Write out a section symbol, specialized for size and endianness.
template<int size, bool big_endian>
sized_write_section_symbol(const Output_section*, Output_symtab_xindex*,
Output_file*, off_t) const;
- // The type of the symbol hash table.
-
- typedef std::pair<Stringpool::Key, Stringpool::Key> Symbol_table_key;
-
- struct Symbol_table_hash
- {
- size_t
- operator()(const Symbol_table_key&) const;
- };
-
- struct Symbol_table_eq
- {
- bool
- operator()(const Symbol_table_key&, const Symbol_table_key&) const;
- };
-
- typedef Unordered_map<Symbol_table_key, Symbol*, Symbol_table_hash,
- Symbol_table_eq> Symbol_table_type;
-
// The type of the list of symbols which have been forced local.
typedef std::vector<Symbol*> Forced_locals;
Copied_symbol_dynobjs copied_symbol_dynobjs_;
// Information parsed from the version script, if any.
const Version_script_info& version_script_;
+ Garbage_collection* gc_;
};
// We inline get_sized_symbol for efficiency.
projects / deliverable / binutils-gdb.git / blobdiff