X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gold%2Fsymtab.h;h=7d99cd52bb61303d002ad5760ee73d119beaefde;hb=7d9e3d985416edccb274f0c704901839234cf4a9;hp=816afb3884a8380053882a8c53fbed1124cff834;hpb=429c15693cbc151d24546c397e8c7435f77e1b14;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/symtab.h b/gold/symtab.h index 816afb3884..7d99cd52bb 100644 --- a/gold/symtab.h +++ b/gold/symtab.h @@ -1,5 +1,25 @@ // symtab.h -- the gold symbol table -*- C++ -*- +// Copyright 2006, 2007, 2008 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. + // Symbol_table // The symbol table. @@ -8,6 +28,7 @@ #include #include "elfcpp.h" +#include "parameters.h" #include "stringpool.h" #include "object.h" @@ -17,6 +38,7 @@ namespace gold { +class Mapfile; class Object; class Relobj; template @@ -25,11 +47,13 @@ class Dynobj; template class Sized_dynobj; class Versions; +class Version_script_info; +class Input_objects; class Output_data; class Output_section; class Output_segment; class Output_file; -class Target; +class Output_symtab_xindex; // 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. @@ -55,7 +79,9 @@ class Symbol // 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 @@ -76,12 +102,34 @@ class Symbol name() const { return this->name_; } + // Return the (ANSI) demangled version of the name, if + // parameters.demangle() is true. Otherwise, return the name. This + // is intended to be used only for logging errors, so it's not + // super-efficient. + std::string + demangled_name() const; + // Return the symbol version. This will return NULL for an // unversioned symbol. const char* version() const { return this->version_; } + // Return whether this version is the default for this symbol name + // (eg, "foo@@V2" is a default version; "foo@V1" is not). Only + // meaningful for versioned symbols. + bool + is_default() const + { + gold_assert(this->version_ != NULL); + return this->is_def_; + } + + // Set that this version is the default for this symbol name. + void + set_is_default() + { this->is_def_ = true; } + // Return the symbol source. Source source() const @@ -98,9 +146,10 @@ class Symbol // Return the index of the section in the input relocatable or // dynamic object file. unsigned int - shndx() const + shndx(bool* is_ordinary) const { gold_assert(this->source_ == FROM_OBJECT); + *is_ordinary = this->is_ordinary_shndx_; return this->u_.from_object.shndx; } @@ -174,6 +223,17 @@ class Symbol set_forwarder() { this->is_forwarder_ = true; } + // Return whether this symbol has an alias in the weak aliases table + // in Symbol_table. + bool + has_alias() const + { return this->has_alias_; } + + // Mark this symbol as having an alias. + void + set_has_alias() + { this->has_alias_ = true; } + // Return whether this symbol needs an entry in the dynamic symbol // table. bool @@ -188,6 +248,11 @@ class Symbol set_needs_dynsym_entry() { this->needs_dynsym_entry_ = true; } + // Return whether this symbol should be added to the dynamic symbol + // table. + bool + should_add_dynsym_entry() const; + // Return whether this symbol has been seen in a regular object. bool in_reg() const @@ -261,25 +326,24 @@ class Symbol { return this->dynsym_index_ != 0; } // Return whether this symbol has an entry in the GOT section. + // For a TLS symbol, this GOT entry will hold its tp-relative offset. bool - has_got_offset() const - { return this->has_got_offset_; } + has_got_offset(unsigned int got_type) const + { return this->got_offsets_.get_offset(got_type) != -1U; } // Return the offset into the GOT section of this symbol. unsigned int - got_offset() const + got_offset(unsigned int got_type) const { - gold_assert(this->has_got_offset()); - return this->got_offset_; + unsigned int got_offset = this->got_offsets_.get_offset(got_type); + gold_assert(got_offset != -1U); + return got_offset; } // Set the GOT offset of this symbol. void - set_got_offset(unsigned int got_offset) - { - this->has_got_offset_ = true; - this->got_offset_ = got_offset; - } + set_got_offset(unsigned int got_type, unsigned int got_offset) + { this->got_offsets_.set_offset(got_type, got_offset); } // Return whether this symbol has an entry in the PLT section. bool @@ -302,24 +366,38 @@ class Symbol this->plt_offset_ = plt_offset; } - // Return true if the final value of this symbol is known at link - // time. + // Return whether this dynamic symbol needs a special value in the + // dynamic symbol table. bool - final_value_is_known(const General_options* options) const + needs_dynsym_value() const + { return this->needs_dynsym_value_; } + + // Set that this dynamic symbol needs a special value in the dynamic + // symbol table. + void + set_needs_dynsym_value() { - if (options->is_shared()) - return false; - return this->source_ != FROM_OBJECT || !this->object()->is_dynamic(); + gold_assert(this->object()->is_dynamic()); + this->needs_dynsym_value_ = true; } + // Return true if the final value of this symbol is known at link + // time. + bool + final_value_is_known() const; + // Return whether this is a defined symbol (not undefined or // common). bool is_defined() const { - return (this->source_ != FROM_OBJECT - || (this->shndx() != elfcpp::SHN_UNDEF - && this->shndx() != elfcpp::SHN_COMMON)); + bool is_ordinary; + if (this->source_ != FROM_OBJECT) + return this->source_ != IS_UNDEFINED; + unsigned int shndx = this->shndx(&is_ordinary); + return (is_ordinary + ? shndx != elfcpp::SHN_UNDEF + : shndx != elfcpp::SHN_COMMON); } // Return true if this symbol is from a dynamic object. @@ -333,15 +411,37 @@ class Symbol bool is_undefined() const { - return this->source_ == FROM_OBJECT && this->shndx() == elfcpp::SHN_UNDEF; + bool 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 + { 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) + || this->source_ == IS_CONSTANT); } // Return whether this is a common symbol. bool is_common() const { + bool is_ordinary; return (this->source_ == FROM_OBJECT - && (this->shndx() == elfcpp::SHN_COMMON + && ((this->shndx(&is_ordinary) == elfcpp::SHN_COMMON + && !is_ordinary) || this->type_ == elfcpp::STT_COMMON)); } @@ -353,6 +453,166 @@ class Symbol || this->visibility_ == elfcpp::STV_PROTECTED); } + // Return true if this symbol can be preempted by a definition in + // another link unit. + bool + is_preemptible() const + { + // It doesn't make sense to ask whether a symbol defined in + // another object is preemptible. + gold_assert(!this->is_from_dynobj()); + + // It doesn't make sense to ask whether an undefined symbol + // is preemptible. + gold_assert(!this->is_undefined()); + + // If a symbol does not have default visibility, it can not be + // seen outside this link unit and therefore is not preemptible. + if (this->visibility_ != elfcpp::STV_DEFAULT) + return false; + + // If this symbol has been forced to be a local symbol by a + // version script, then it is not visible outside this link unit + // and is not preemptible. + if (this->is_forced_local_) + return false; + + // If we are not producing a shared library, then nothing is + // preemptible. + if (!parameters->options().shared()) + return false; + + // If the user used -Bsymbolic, then nothing is preemptible. + if (parameters->options().Bsymbolic()) + return false; + + // If the user used -Bsymbolic-functions, then functions are not + // preemptible. We explicitly check for not being STT_OBJECT, + // rather than for being STT_FUNC, because that is what the GNU + // linker does. + if (this->type() != elfcpp::STT_OBJECT + && parameters->options().Bsymbolic_functions()) + return false; + + // Otherwise the symbol is preemptible. + return true; + } + + // Return true if this symbol is a function that needs a PLT entry. + // If the symbol is defined in a dynamic object or if it is subject + // to pre-emption, we need to make a PLT entry. If we're doing a + // static link, we don't create PLT entries. + bool + needs_plt_entry() const + { + return (!parameters->doing_static_link() + && this->type() == elfcpp::STT_FUNC + && (this->is_from_dynobj() + || this->is_undefined() + || this->is_preemptible())); + } + + // When determining whether a reference to a symbol needs a dynamic + // relocation, we need to know several things about the reference. + // These flags may be or'ed together. + enum Reference_flags + { + // Reference to the symbol's absolute address. + ABSOLUTE_REF = 1, + // A non-PIC reference. + NON_PIC_REF = 2, + // A function call. + FUNCTION_CALL = 4 + }; + + // Given a direct absolute or pc-relative static relocation against + // the global symbol, this function returns whether a dynamic relocation + // is needed. + + bool + needs_dynamic_reloc(int flags) const + { + // No dynamic relocations in a static link! + if (parameters->doing_static_link()) + return false; + + // A reference to a weak 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()) + return false; + + // A reference to an absolute symbol does not need a dynamic relocation. + if (this->is_absolute()) + return false; + + // An absolute reference within a position-independent output file + // will need a dynamic relocation. + if ((flags & ABSOLUTE_REF) + && parameters->options().output_is_position_independent()) + return true; + + // A function call that can branch to a local PLT entry does not need + // a dynamic relocation. A non-pic pc-relative function call in a + // shared library cannot use a PLT entry. + if ((flags & FUNCTION_CALL) + && this->has_plt_offset() + && !((flags & NON_PIC_REF) && parameters->options().shared())) + return false; + + // A reference to any PLT entry in a non-position-independent executable + // does not need a dynamic relocation. + if (!parameters->options().output_is_position_independent() + && this->has_plt_offset()) + return false; + + // A reference to a symbol defined in a dynamic object or to a + // symbol that is preemptible will need a dynamic relocation. + if (this->is_from_dynobj() + || this->is_undefined() + || this->is_preemptible()) + return true; + + // For all other cases, return FALSE. + 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. + // The caller must determine separately whether the static relocation + // is compatible with a relative relocation. + + bool + can_use_relative_reloc(bool is_function_call) const + { + // A function call that can branch to a local PLT entry can + // use a RELATIVE relocation. + if (is_function_call && this->has_plt_offset()) + return true; + + // A reference to a symbol defined in a dynamic object or to a + // symbol that is preemptible can not use a RELATIVE relocaiton. + if (this->is_from_dynobj() + || this->is_undefined() + || this->is_preemptible()) + return false; + + // For all other cases, return TRUE. + return true; + } + + // Return the output section where this symbol is defined. Return + // NULL if the symbol has an absolute value. + Output_section* + output_section() const; + + // Set the symbol's output section. This is used for symbols + // defined in scripts. This should only be called after the symbol + // table has been finalized. + void + set_output_section(Output_section*); + // Return whether there should be a warning for references to this // symbol. bool @@ -364,6 +624,28 @@ class Symbol set_has_warning() { this->has_warning_ = true; } + // Return whether this symbol is defined by a COPY reloc from a + // dynamic object. + bool + is_copied_from_dynobj() const + { return this->is_copied_from_dynobj_; } + + // Mark this symbol as defined by a COPY reloc. + void + set_is_copied_from_dynobj() + { this->is_copied_from_dynobj_ = true; } + + // Return whether this symbol is forced to visibility STB_LOCAL + // by a "local:" entry in a version script. + bool + is_forced_local() const + { return this->is_forced_local_; } + + // Mark this symbol as forced to STB_LOCAL visibility. + void + set_is_forced_local() + { this->is_forced_local_ = true; } + protected: // Instances of this class should always be created at a specific // size. @@ -376,33 +658,59 @@ class Symbol elfcpp::STT type, elfcpp::STB binding, elfcpp::STV visibility, unsigned char nonvis); - // Initialize fields from an ELF symbol in OBJECT. + // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the + // section index, IS_ORDINARY is whether it is a normal section + // index rather than a special code. template void - init_base(const char *name, const char* version, Object* object, - const elfcpp::Sym&); + init_base_object(const char *name, const char* version, Object* object, + const elfcpp::Sym&, 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 void - override_base(const elfcpp::Sym&, Object* object, - const char* version); + override_base(const elfcpp::Sym&, unsigned int st_shndx, + bool is_ordinary, Object* object, const char* version); + + // Override existing symbol with a special symbol. + 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 + allocate_base_common(Output_data*); private: Symbol(const Symbol&); @@ -462,28 +770,31 @@ class Symbol unsigned int dynsym_index_; // If this symbol has an entry in the GOT section (has_got_offset_ - // is true), this is the offset from the start of the GOT section. - unsigned int got_offset_; + // is true), this holds the offset from the start of the GOT section. + // A symbol may have more than one GOT offset (e.g., when mixing + // modules compiled with two different TLS models), but will usually + // have at most one. + Got_offset_list got_offsets_; // If this symbol has an entry in the PLT section (has_plt_offset_ // is true), then this is the offset from the start of the PLT // section. unsigned int plt_offset_; - // Symbol type. + // Symbol type (bits 0 to 3). elfcpp::STT type_ : 4; - // Symbol binding. + // Symbol binding (bits 4 to 7). elfcpp::STB binding_ : 4; - // Symbol visibility. + // Symbol visibility (bits 8 to 9). elfcpp::STV visibility_ : 2; - // Rest of symbol st_other field. + // Rest of symbol st_other field (bits 10 to 15). unsigned int nonvis_ : 6; - // The type of symbol. + // The type of symbol (bits 16 to 18). Source source_ : 3; // True if this symbol always requires special target-specific - // handling. + // handling (bit 19). bool is_target_special_ : 1; - // True if this is the default version of the symbol. + // True if this is the default version of the symbol (bit 20). bool is_def_ : 1; // True if this symbol really forwards to another symbol. This is // used when we discover after the fact that two different entries @@ -491,20 +802,35 @@ class Symbol // never be set for a symbol found in the hash table, but may be set // for a symbol found in the list of symbols attached to an Object. // It forwards to the symbol found in the forwarders_ map of - // Symbol_table. + // Symbol_table (bit 21). bool is_forwarder_ : 1; - // True if this symbol needs to be in the dynamic symbol table. + // True if the symbol has an alias in the weak_aliases table in + // Symbol_table (bit 22). + bool has_alias_ : 1; + // True if this symbol needs to be in the dynamic symbol table (bit + // 23). bool needs_dynsym_entry_ : 1; - // True if we've seen this symbol in a regular object. + // True if we've seen this symbol in a regular object (bit 24). bool in_reg_ : 1; - // True if we've seen this symbol in a dynamic object. + // True if we've seen this symbol in a dynamic object (bit 25). bool in_dyn_ : 1; - // True if the symbol has an entry in the GOT section. - bool has_got_offset_ : 1; - // True if the symbol has an entry in the PLT section. + // True if the symbol has an entry in the PLT section (bit 26). bool has_plt_offset_ : 1; - // True if there is a warning for this symbol. + // True if this is a dynamic symbol which needs a special value in + // the dynamic symbol table (bit 27). + bool needs_dynsym_value_ : 1; + // True if there is a warning for this symbol (bit 28). bool has_warning_ : 1; + // True if we are using a COPY reloc for this symbol, so that the + // real definition lives in a dynamic object (bit 29). + bool is_copied_from_dynobj_ : 1; + // True if this symbol was forced to local visibility by a version + // script (bit 30). + 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. + bool is_ordinary_shndx_ : 1; }; // The parts of a symbol which are size specific. Using a template @@ -520,34 +846,49 @@ class Sized_symbol : public Symbol Sized_symbol() { } - // Initialize fields from an ELF symbol in OBJECT. + // Initialize fields from an ELF symbol in OBJECT. ST_SHNDX is the + // section index, IS_ORDINARY is whether it is a normal section + // index rather than a special code. template void - init(const char *name, const char* version, Object* object, - const elfcpp::Sym&); + init_object(const char *name, const char* version, Object* object, + const elfcpp::Sym&, 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 void - override(const elfcpp::Sym&, Object* object, - const char* version); + override(const elfcpp::Sym&, unsigned int st_shndx, + bool is_ordinary, Object* object, const char* version); + + // Override existing symbol with a special symbol. + void + override_with_special(const Sized_symbol*); // Return the symbol's value. Value_type @@ -571,6 +912,11 @@ class Sized_symbol : public Symbol set_value(Value_type value) { this->value_ = value; } + // Allocate a common symbol by giving it a location in the output + // file. + void + allocate_common(Output_data*, Value_type value); + private: Sized_symbol(const Sized_symbol&); Sized_symbol& operator=(const Sized_symbol&); @@ -676,19 +1022,22 @@ class Warnings : warnings_() { } - // Add a warning for symbol NAME in section SHNDX in object OBJ. + // Add a warning for symbol NAME in object OBJ. WARNING is the text + // of the warning. void add_warning(Symbol_table* symtab, const char* name, Object* obj, - unsigned int shndx); + const std::string& warning); // For each symbol for which we should give a warning, make a note // on the symbol. void note_warnings(Symbol_table* symtab); - // Issue a warning for a reference to SYM at LOCATION. + // Issue a warning for a reference to SYM at RELINFO's location. + template void - issue_warning(const Symbol* sym, const std::string& location) const; + issue_warning(const Symbol* sym, const Relocate_info*, + size_t relnum, off_t reloffset) const; private: Warnings(const Warnings&); @@ -699,29 +1048,23 @@ class Warnings { // The object the warning is in. Object* object; - // The index of the warning section. - unsigned int shndx; - // The warning text if we have already loaded it. + // The warning text. std::string text; Warning_location() - : object(NULL), shndx(0), text() + : object(NULL), text() { } void - set(Object* o, unsigned int s) + set(Object* o, const std::string& t) { this->object = o; - this->shndx = s; + this->text = t; } - - void - set_text(const char* t, off_t l) - { this->text.assign(t, l); } }; // A mapping from warning symbol names (canonicalized in - // Symbol_table's namepool_ field) to + // Symbol_table's namepool_ field) to warning information. typedef Unordered_map Warning_table; Warning_table warnings_; @@ -732,20 +1075,25 @@ class Warnings class Symbol_table { public: - Symbol_table(); + // COUNT is an estimate of how many symbosl will be inserted in the + // symbol table. It's ok to put 0 if you don't know; a correct + // guess will just save some CPU by reducing hashtable resizes. + Symbol_table(unsigned int count, const Version_script_info& version_script); ~Symbol_table(); // Add COUNT external symbols from the relocatable object RELOBJ to - // the symbol table. SYMS is the symbols, 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. + // 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. template void add_from_relobj(Sized_relobj* relobj, const unsigned char* syms, size_t count, - const char* sym_names, size_t sym_name_size, - Symbol** sympointers); + size_t symndx_offset, const char* sym_names, + size_t sym_name_size, + typename Sized_relobj::Symbols*); // Add COUNT dynamic symbols from the dynamic object DYNOBJ to the // symbol table. SYMS is the symbols. SYM_NAMES is their names. @@ -762,7 +1110,7 @@ class Symbol_table // Define a special symbol based on an Output_data. It is a // multiple definition error if this symbol is already defined. Symbol* - define_in_output_data(const Target*, const char* name, const char* version, + define_in_output_data(const char* name, const char* version, Output_data*, uint64_t value, uint64_t symsize, elfcpp::STT type, elfcpp::STB binding, elfcpp::STV visibility, unsigned char nonvis, @@ -771,9 +1119,8 @@ class Symbol_table // Define a special symbol based on an Output_segment. It is a // multiple definition error if this symbol is already defined. Symbol* - define_in_output_segment(const Target*, const char* name, - const char* version, Output_segment*, - uint64_t value, uint64_t symsize, + define_in_output_segment(const char* name, const char* version, + Output_segment*, uint64_t value, uint64_t symsize, elfcpp::STT type, elfcpp::STB binding, elfcpp::STV visibility, unsigned char nonvis, Symbol::Segment_offset_base, bool only_if_ref); @@ -781,20 +1128,31 @@ class Symbol_table // Define a special symbol with a constant value. It is a multiple // definition error if this symbol is already defined. Symbol* - define_as_constant(const Target*, const char* name, const char* version, + define_as_constant(const char* name, const char* version, uint64_t value, uint64_t symsize, elfcpp::STT type, elfcpp::STB binding, elfcpp::STV visibility, - unsigned char nonvis, bool only_if_ref); + unsigned char nonvis, bool only_if_ref, + bool force_override); - // Define a set of symbols in output sections. + // Define a set of symbols in output sections. If ONLY_IF_REF is + // true, only define them if they are referenced. void - define_symbols(const Layout*, const Target*, int count, - const Define_symbol_in_section*); + define_symbols(const Layout*, int count, const Define_symbol_in_section*, + bool only_if_ref); - // Define a set of symbols in output segments. + // Define a set of symbols in output segments. If ONLY_IF_REF is + // true, only defined them if they are referenced. void - define_symbols(const Layout*, const Target*, int count, - const Define_symbol_in_segment*); + define_symbols(const Layout*, int count, const Define_symbol_in_segment*, + bool only_if_ref); + + // Define SYM 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 + void + define_with_copy_reloc(Sized_symbol* sym, Output_data* posd, + typename elfcpp::Elf_types::Elf_Addr); // Look up a symbol. Symbol* @@ -804,19 +1162,14 @@ class Symbol_table Symbol* resolve_forwards(const Symbol* from) const; - // Return the bitsize (32 or 64) of the symbols in the table. - int - get_size() const - { return this->size_; } - // Return the sized version of a symbol in this table. template Sized_symbol* - get_sized_symbol(Symbol* ACCEPT_SIZE) const; + get_sized_symbol(Symbol*) const; template const Sized_symbol* - get_sized_symbol(const Symbol* ACCEPT_SIZE) const; + get_sized_symbol(const Symbol*) const; // Return the count of undefined symbols seen. int @@ -825,62 +1178,91 @@ class Symbol_table // Allocate the common symbols void - allocate_commons(const General_options&, Layout*); + allocate_commons(Layout*, Mapfile*); - // Add a warning for symbol NAME in section SHNDX in object OBJ. + // Add a warning for symbol NAME in object OBJ. WARNING is the text + // of the warning. void - add_warning(const char* name, Object* obj, unsigned int shndx) - { this->warnings_.add_warning(this, name, obj, shndx); } + add_warning(const char* name, Object* obj, const std::string& warning) + { this->warnings_.add_warning(this, name, obj, warning); } // Canonicalize a symbol name for use in the hash table. const char* canonicalize_name(const char* name) - { return this->namepool_.add(name, NULL); } + { return this->namepool_.add(name, true, NULL); } // Possibly issue a warning for a reference to SYM at LOCATION which // is in OBJ. + template void - issue_warning(const Symbol* sym, const std::string& location) const - { this->warnings_.issue_warning(sym, location); } + issue_warning(const Symbol* sym, + const Relocate_info* relinfo, + size_t relnum, off_t reloffset) const + { this->warnings_.issue_warning(sym, relinfo, relnum, reloffset); } + + // Check candidate_odr_violations_ to find symbols with the same name + // but apparently different definitions (different source-file/line-no). + 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* + get_copy_source(const Symbol* sym) const; // Set the dynamic symbol indexes. INDEX is the index of the first // global dynamic symbol. Pointers to the symbols are stored into // the vector. The names are stored into the Stringpool. This // returns an updated dynamic symbol index. unsigned int - set_dynsym_indexes(const General_options*, const Target*, unsigned int index, - std::vector*, Stringpool*, Versions*); + set_dynsym_indexes(unsigned int index, std::vector*, + Stringpool*, Versions*); // Finalize the symbol table after we have set the final addresses // of all the input sections. This sets the final symbol indexes, - // values and adds the names to *POOL. INDEX is the index of the - // first global symbol. OFF is the file offset of the global symbol - // table, DYNOFF is the offset of the globals in the dynamic symbol - // table, DYN_GLOBAL_INDEX is the index of the first global dynamic - // symbol, and DYNCOUNT is the number of global dynamic symbols. - // This records the parameters, and returns the new file offset. + // values and adds the names to *POOL. *PLOCAL_SYMCOUNT is the + // index of the first global symbol. OFF is the file offset of the + // global symbol table, DYNOFF is the offset of the globals in the + // dynamic symbol table, DYN_GLOBAL_INDEX is the index of the first + // global dynamic symbol, and DYNCOUNT is the number of global + // dynamic symbols. This records the parameters, and returns the + // new file offset. It updates *PLOCAL_SYMCOUNT if it created any + // local symbols. off_t - finalize(unsigned int index, off_t off, off_t dynoff, - size_t dyn_global_index, size_t dyncount, Stringpool* pool); + finalize(off_t off, off_t dynoff, size_t dyn_global_index, size_t dyncount, + Stringpool* pool, unsigned int *plocal_symcount); // Write out the global symbols. void - write_globals(const Target*, const Stringpool*, const Stringpool*, + write_globals(const Input_objects*, const Stringpool*, const Stringpool*, + Output_symtab_xindex*, Output_symtab_xindex*, Output_file*) const; // Write out a section symbol. Return the updated offset. void - write_section_symbol(const Target*, const Output_section*, Output_file*, - off_t) const; + write_section_symbol(const Output_section*, Output_symtab_xindex*, + Output_file*, off_t) const; + + // Dump statistical information to stderr. + void + print_stats() const; + + // Return the version script information. + const Version_script_info& + version_script() const + { return version_script_; } private: Symbol_table(const Symbol_table&); Symbol_table& operator=(const Symbol_table&); - // Set the size (32 or 64) of the symbols in the table. - void - set_size(int size) - { this->size_ = size; } + // The type of the list of common symbols. + typedef std::vector Commons_type; // Make FROM a forwarder symbol to TO. void @@ -888,35 +1270,74 @@ class Symbol_table // Add a symbol. template - Symbol* + Sized_symbol* add_from_object(Object*, const char *name, Stringpool::Key name_key, const char *version, Stringpool::Key version_key, - bool def, const elfcpp::Sym& sym); + bool def, const elfcpp::Sym& sym, + unsigned int st_shndx, bool is_ordinary, + unsigned int orig_st_shndx); // Resolve symbols. template - static void + void resolve(Sized_symbol* to, const elfcpp::Sym& sym, + unsigned int st_shndx, bool is_ordinary, + unsigned int orig_st_shndx, Object*, const char* version); template - static void + void resolve(Sized_symbol* to, const Sized_symbol* from, - const char* version ACCEPT_SIZE_ENDIAN); + const char* version); + + // Record that a symbol is forced to be local by a version script. + void + force_local(Symbol*); + + // Adjust NAME and *NAME_KEY for wrapping. + const char* + wrap_symbol(Object* object, const char*, Stringpool::Key* name_key); + + // Whether we should override a symbol, based on flags in + // resolve.cc. + static bool + should_override(const Symbol*, unsigned int, Object*, bool*); + + // Override a symbol. + template + void + override(Sized_symbol* tosym, + const elfcpp::Sym& fromsym, + unsigned int st_shndx, bool is_ordinary, + Object* object, const char* version); + + // Whether we should override a symbol with a special symbol which + // is automatically defined by the linker. + static bool + should_override_with_special(const Symbol*); + + // Override a symbol with a special symbol. + template + void + override_with_special(Sized_symbol* tosym, + const Sized_symbol* fromsym); + + // Record all weak alias sets for a dynamic object. + template + void + record_weak_aliases(std::vector*>*); // Define a special symbol. template Sized_symbol* - define_special_symbol(const Target* target, const char* name, - const char* version, bool only_if_ref - ACCEPT_SIZE_ENDIAN); + define_special_symbol(const char** pname, const char** pversion, + bool only_if_ref, Sized_symbol** poldsym); // Define a symbol in an Output_data, sized version. template Sized_symbol* - do_define_in_output_data(const Target*, const char* name, - const char* version, Output_data*, + do_define_in_output_data(const char* name, const char* version, Output_data*, typename elfcpp::Elf_types::Elf_Addr value, typename elfcpp::Elf_types::Elf_WXword ssize, elfcpp::STT type, elfcpp::STB binding, @@ -927,7 +1348,7 @@ class Symbol_table template Sized_symbol* do_define_in_output_segment( - const Target*, const char* name, const char* version, Output_segment* os, + const char* name, const char* version, Output_segment* os, typename elfcpp::Elf_types::Elf_Addr value, typename elfcpp::Elf_types::Elf_WXword ssize, elfcpp::STT type, elfcpp::STB binding, @@ -938,40 +1359,74 @@ class Symbol_table template Sized_symbol* do_define_as_constant( - const Target*, const char* name, const char* version, + const char* name, const char* version, typename elfcpp::Elf_types::Elf_Addr value, typename elfcpp::Elf_types::Elf_WXword ssize, elfcpp::STT type, elfcpp::STB binding, elfcpp::STV visibility, unsigned char nonvis, - bool only_if_ref); + bool only_if_ref, bool force_override); + + // Add any undefined symbols named on the command line to the symbol + // table, sized version. + template + void + do_add_undefined_symbols_from_command_line(); // Allocate the common symbols, sized version. template void - do_allocate_commons(const General_options&, Layout*); + do_allocate_commons(Layout*, Mapfile*); + + // Allocate the common symbols from one list. + template + void + do_allocate_commons_list(Layout*, bool is_tls, Commons_type*, Mapfile*); + + // Implement detect_odr_violations. + template + void + sized_detect_odr_violations() const; // Finalize symbols specialized for size. template off_t - sized_finalize(unsigned int, off_t, Stringpool*); + sized_finalize(off_t, Stringpool*, unsigned int*); + + // Finalize a symbol. Return whether it should be added to the + // symbol table. + template + bool + sized_finalize_symbol(Symbol*); + + // Add a symbol the final symtab by setting its index. + template + void + add_to_final_symtab(Symbol*, Stringpool*, unsigned int* pindex, off_t* poff); // Write globals specialized for size and endianness. template void - sized_write_globals(const Target*, const Stringpool*, const Stringpool*, - Output_file*) const; + sized_write_globals(const Input_objects*, const Stringpool*, + const Stringpool*, Output_symtab_xindex*, + Output_symtab_xindex*, Output_file*) const; // Write out a symbol to P. template void - sized_write_symbol(Sized_symbol*, unsigned int shndx, - const Stringpool*, unsigned char* p - ACCEPT_SIZE_ENDIAN) const; + sized_write_symbol(Sized_symbol*, + typename elfcpp::Elf_types::Elf_Addr value, + unsigned int shndx, + const Stringpool*, unsigned char* p) const; + + // Possibly warn about an undefined symbol from a dynamic object. + void + warn_about_undefined_dynobj_symbol(const Input_objects*, Symbol*) const; // Write out a section symbol, specialized for size and endianness. template void - sized_write_section_symbol(const Output_section*, Output_file*, off_t) const; + sized_write_section_symbol(const Output_section*, Output_symtab_xindex*, + Output_file*, off_t) const; // The type of the symbol hash table. @@ -992,72 +1447,109 @@ class Symbol_table typedef Unordered_map Symbol_table_type; - // The type of the list of common symbols. + // The type of the list of symbols which have been forced local. + typedef std::vector Forced_locals; - typedef std::vector Commons_type; + // A map from symbols with COPY relocs to the dynamic objects where + // they are defined. + typedef Unordered_map Copied_symbol_dynobjs; + + // A map from symbol name (as a pointer into the namepool) to all + // the locations the symbols is (weakly) defined (and certain other + // conditions are met). This map will be used later to detect + // possible One Definition Rule (ODR) violations. + struct Symbol_location + { + Object* object; // Object where the symbol is defined. + unsigned int shndx; // Section-in-object where the symbol is defined. + off_t offset; // Offset-in-section where the symbol is defined. + bool operator==(const Symbol_location& that) const + { + return (this->object == that.object + && this->shndx == that.shndx + && this->offset == that.offset); + } + }; + + struct Symbol_location_hash + { + size_t operator()(const Symbol_location& loc) const + { return reinterpret_cast(loc.object) ^ loc.offset ^ loc.shndx; } + }; - // The size of the symbols in the symbol table (32 or 64). - int size_; + typedef Unordered_map > + Odr_map; // We increment this every time we see a new undefined symbol, for // use in archive groups. int saw_undefined_; - // The index of the first global symbol in the output file. unsigned int first_global_index_; - // The file offset within the output symtab section where we should // write the table. off_t offset_; - // The number of global symbols we want to write out. - size_t output_count_; - + unsigned int output_count_; // The file offset of the global dynamic symbols, or 0 if none. off_t dynamic_offset_; - // The index of the first global dynamic symbol. unsigned int first_dynamic_global_index_; - // The number of global dynamic symbols, or 0 if none. - off_t dynamic_count_; - + unsigned int dynamic_count_; // The symbol hash table. Symbol_table_type table_; - // A pool of symbol names. This is used for all global symbols. // Entries in the hash table point into this pool. Stringpool namepool_; - // Forwarding symbols. Unordered_map forwarders_; - + // Weak aliases. A symbol in this list points to the next alias. + // The aliases point to each other in a circular list. + Unordered_map weak_aliases_; // We don't expect there to be very many common symbols, so we keep // a list of them. When we find a common symbol we add it to this // list. It is possible that by the time we process the list the // symbol is no longer a common symbol. It may also have become a // forwarder. Commons_type commons_; - + // This is like the commons_ field, except that it holds TLS common + // symbols. + Commons_type tls_commons_; + // A list of symbols which have been forced to be local. We don't + // expect there to be very many of them, so we keep a list of them + // rather than walking the whole table to find them. + Forced_locals forced_locals_; // Manage symbol warnings. Warnings warnings_; + // Manage potential One Definition Rule (ODR) violations. + Odr_map candidate_odr_violations_; + + // When we emit a COPY reloc for a symbol, we define it in an + // Output_data. When it's time to emit version information for it, + // we need to know the dynamic object in which we found the original + // definition. This maps symbols with COPY relocs to the dynamic + // object where they were defined. + Copied_symbol_dynobjs copied_symbol_dynobjs_; + // Information parsed from the version script, if any. + const Version_script_info& version_script_; }; // We inline get_sized_symbol for efficiency. template Sized_symbol* -Symbol_table::get_sized_symbol(Symbol* sym ACCEPT_SIZE) const +Symbol_table::get_sized_symbol(Symbol* sym) const { - gold_assert(size == this->get_size()); + gold_assert(size == parameters->target().get_size()); return static_cast*>(sym); } template const Sized_symbol* -Symbol_table::get_sized_symbol(const Symbol* sym ACCEPT_SIZE) const +Symbol_table::get_sized_symbol(const Symbol* sym) const { - gold_assert(size == this->get_size()); + gold_assert(size == parameters->target().get_size()); return static_cast*>(sym); }