X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gold%2Fsymtab.h;h=1a1f1c78633b76d05224f5d6ec6878b931a8d8a7;hb=55c144e691ec05a7b8231b5c58dc6d6659a1c4eb;hp=419613810450b340b62c2a33b8efd8ee047e5cf4;hpb=cdc29364d17efa132576dc586850a378bc569433;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/symtab.h b/gold/symtab.h index 4196138104..1a1f1c7863 100644 --- a/gold/symtab.h +++ b/gold/symtab.h @@ -1,6 +1,6 @@ // symtab.h -- the gold symbol table -*- C++ -*- -// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. +// Copyright (C) 2006-2015 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -42,7 +42,7 @@ class Mapfile; class Object; class Relobj; template -class Sized_relobj; +class Sized_relobj_file; template class Sized_pluginobj; class Dynobj; @@ -62,7 +62,7 @@ class Garbage_collection; class Icf; // 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. +// can have a lot of entries, so we don't want this class too big. // Size dependent fields can be found in the template class // Sized_symbol. Targets may support their own derived classes. @@ -121,6 +121,10 @@ class Symbol version() const { return this->version_; } + void + clear_version() + { this->version_ = NULL; } + // 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. @@ -136,6 +140,15 @@ class Symbol set_is_default() { this->is_def_ = true; } + // Set that this version is not the default for this symbol name. + void + set_is_not_default() + { this->is_def_ = false; } + + // Return the symbol's name as name@version (or name@@version). + std::string + versioned_name() const; + // Return the symbol source. Source source() const @@ -207,6 +220,11 @@ class Symbol type() const { return this->type_; } + // Set the symbol type. + void + set_type(elfcpp::STT type) + { this->type_ = type; } + // Return true for function symbol. bool is_func() const @@ -230,7 +248,7 @@ class Symbol override_visibility(elfcpp::STV); // Set whether the symbol was originally a weak undef or a regular undef - // when resolved by a dynamic def. + // when resolved by a dynamic def or by a special symbol. inline void set_undef_binding(elfcpp::STB bind) { @@ -241,7 +259,8 @@ class Symbol } } - // Return TRUE if a weak undef was resolved by a dynamic def. + // Return TRUE if a weak undef was resolved by a dynamic def or + // by a special symbol. inline bool is_undef_binding_weak() const { return this->undef_binding_weak_; } @@ -251,6 +270,11 @@ class Symbol nonvis() const { return this->nonvis_; } + // Set the non-visibility part of the st_other field. + void + set_nonvis(unsigned int nonvis) + { this->nonvis_ = nonvis; } + // Return whether this symbol is a forwarder. This will never be // true of a symbol found in the hash table, but may be true of // symbol pointers attached to object files. @@ -504,7 +528,22 @@ class Symbol // Return whether this is a weak undefined symbol. bool is_weak_undefined() const - { return this->is_undefined() && this->binding() == elfcpp::STB_WEAK; } + { + return (this->is_undefined() + && (this->binding() == elfcpp::STB_WEAK + || this->is_undef_binding_weak() + || parameters->options().weak_unresolved_symbols())); + } + + // Return whether this is a strong undefined symbol. + bool + is_strong_undefined() const + { + return (this->is_undefined() + && this->binding() != elfcpp::STB_WEAK + && !this->is_undef_binding_weak() + && !parameters->options().weak_unresolved_symbols()); + } // Return whether this is an absolute symbol. bool @@ -523,8 +562,6 @@ class Symbol { if (this->source_ != FROM_OBJECT) return false; - if (this->type_ == elfcpp::STT_COMMON) - return true; bool is_ordinary; unsigned int shndx = this->shndx(&is_ordinary); return !is_ordinary && Symbol::is_common_shndx(shndx); @@ -534,8 +571,9 @@ class Symbol bool is_externally_visible() const { - return (this->visibility_ == elfcpp::STV_DEFAULT - || this->visibility_ == elfcpp::STV_PROTECTED); + return ((this->visibility_ == elfcpp::STV_DEFAULT + || this->visibility_ == elfcpp::STV_PROTECTED) + && !this->is_forced_local_); } // Return true if this symbol can be preempted by a definition in @@ -567,7 +605,11 @@ class Symbol if (!parameters->options().shared()) return false; - // If the user used -Bsymbolic, then nothing is preemptible. + // If the symbol was named in a --dynamic-list script, it is preemptible. + if (parameters->options().in_dynamic_list(this->name())) + return true; + + // If the user used -Bsymbolic, then nothing (else) is preemptible. if (parameters->options().Bsymbolic()) return false; @@ -629,7 +671,10 @@ class Symbol // A TLS-related reference. TLS_REF = 4, // A reference that can always be treated as a function call. - FUNCTION_CALL = 8 + FUNCTION_CALL = 8, + // When set, says that dynamic relocations are needed even if a + // symbol has a plt entry. + FUNC_DESC_ABI = 16, }; // Given a direct absolute or pc-relative static relocation against @@ -666,7 +711,8 @@ class Symbol // 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() + if (!(flags & FUNC_DESC_ABI) + && !parameters->options().output_is_position_independent() && this->has_plt_offset()) return false; @@ -758,6 +804,18 @@ class Symbol void set_output_section(Output_section*); + // Set the symbol's output segment. This is used for pre-defined + // symbols whose segments aren't known until after layout is done + // (e.g., __ehdr_start). + void + set_output_segment(Output_segment*, Segment_offset_base); + + // Set the symbol to undefined. This is used for pre-defined + // symbols whose segments aren't known until after layout is done + // (e.g., __ehdr_start). + void + set_undefined(); + // Return whether there should be a warning for references to this // symbol. bool @@ -797,12 +855,21 @@ class Symbol bool may_need_copy_reloc() const { - return (!parameters->options().output_is_position_independent() - && parameters->options().copyreloc() + return (parameters->options().copyreloc() && this->is_from_dynobj() && !this->is_func()); } + // Return true if this symbol was predefined by the linker. + bool + is_predefined() const + { return this->is_predefined_; } + + // Return true if this is a C++ vtable symbol. + bool + is_cxx_vtable() const + { return is_prefix_of("_ZTV", this->name_); } + protected: // Instances of this class should always be created at a specific // size. @@ -828,7 +895,8 @@ class Symbol void 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); + unsigned char nonvis, bool offset_is_from_end, + bool is_predefined); // Initialize fields for an Output_segment. void @@ -836,13 +904,14 @@ class Symbol Output_segment* os, elfcpp::STT type, elfcpp::STB binding, elfcpp::STV visibility, unsigned char nonvis, - Segment_offset_base offset_base); + Segment_offset_base offset_base, + bool is_predefined); // Initialize fields for a constant. void init_base_constant(const char* name, const char* version, elfcpp::STT type, elfcpp::STB binding, elfcpp::STV visibility, - unsigned char nonvis); + unsigned char nonvis, bool is_predefined); // Initialize fields for an undefined symbol. void @@ -981,7 +1050,12 @@ class Symbol // index, not one of the special codes from SHN_LORESERVE to // SHN_HIRESERVE (bit 29). bool is_ordinary_shndx_ : 1; - // True if we've seen this symbol in a real ELF object (bit 30). + // True if we've seen this symbol in a "real" ELF object (bit 30). + // If the symbol has been seen in a relocatable, non-IR, object file, + // it's known to be referenced from outside the IR. A reference from + // a dynamic object doesn't count as a "real" ELF, and we'll simply + // mark the symbol as "visible" from outside the IR. The compiler + // can use this distinction to guide its handling of COMDAT symbols. bool in_real_elf_ : 1; // True if this symbol is defined in a section which was discarded // (bit 31). @@ -989,8 +1063,10 @@ class Symbol // True if UNDEF_BINDING_WEAK_ has been set (bit 32). bool undef_binding_set_ : 1; // True if this symbol was a weak undef resolved by a dynamic def - // (bit 33). + // or by a special symbol (bit 33). bool undef_binding_weak_ : 1; + // True if this symbol is a predefined linker symbol (bit 34). + bool is_predefined_ : 1; }; // The parts of a symbol which are size specific. Using a template @@ -1020,20 +1096,20 @@ class Sized_symbol : public Symbol 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); + bool offset_is_from_end, bool is_predefined); // Initialize fields for an Output_segment. void 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); + Segment_offset_base offset_base, bool is_predefined); // Initialize fields for a constant. void init_constant(const char* name, const char* version, Value_type value, Size_type symsize, elfcpp::STT, elfcpp::STB, elfcpp::STV, - unsigned char nonvis); + unsigned char nonvis, bool is_predefined); // Initialize fields for an undefined symbol. void @@ -1161,6 +1237,25 @@ struct Define_symbol_in_segment bool only_if_ref; }; +// Specify an object/section/offset location. Used by ODR code. + +struct Symbol_location +{ + // Object where the symbol is defined. + Object* object; + // Section-in-object where the symbol is defined. + unsigned int shndx; + // For relocatable objects, offset-in-section where the symbol is defined. + // For dynamic objects, address where the symbol is defined. + off_t offset; + bool operator==(const Symbol_location& that) const + { + return (this->object == that.object + && this->shndx == that.shndx + && this->offset == that.offset); + } +}; + // This class manages warnings. Warnings are a GNU extension. When // we see a section named .gnu.warning.SYM in an object file, and if // we wind using the definition of SYM from that object file, then we @@ -1250,6 +1345,9 @@ class Symbol_table SCRIPT, // Predefined by the linker. PREDEFINED, + // Defined by the linker during an incremental base link, but not + // a predefined symbol (e.g., common, defined in script). + INCREMENTAL_BASE, }; // The order in which we sort common symbols. @@ -1277,7 +1375,7 @@ class Symbol_table // Returns true if ICF determined that this is a duplicate section. bool - is_section_folded(Object* obj, unsigned int shndx) const; + is_section_folded(Relobj* obj, unsigned int shndx) const; void set_gc(Garbage_collection* gc) @@ -1291,10 +1389,9 @@ class Symbol_table void gc_mark_undef_symbols(Layout*); - // During garbage collection, this ensures externally visible symbols - // are not treated as garbage while building shared objects. + // This tells garbage collection that this symbol is referenced. void - gc_mark_symbol_for_shlib(Symbol* sym); + gc_mark_symbol(Symbol* sym); // During garbage collection, this keeps sections that correspond to // symbols seen in dynamic objects. @@ -1309,11 +1406,11 @@ class Symbol_table // *DEFINED to the number of defined symbols. template void - add_from_relobj(Sized_relobj* relobj, + add_from_relobj(Sized_relobj_file* relobj, const unsigned char* syms, size_t count, size_t symndx_offset, const char* sym_names, size_t sym_name_size, - typename Sized_relobj::Symbols*, + typename Sized_relobj_file::Symbols*, size_t* defined); // Add one external symbol from the plugin object OBJ to the symbol table. @@ -1335,13 +1432,13 @@ class Symbol_table const char* sym_names, size_t sym_name_size, const unsigned char* versym, size_t versym_size, const std::vector*, - typename Sized_relobj::Symbols*, + typename Sized_relobj_file::Symbols*, size_t* defined); // Add one external symbol from the incremental object OBJ to the symbol // table. Returns a pointer to the resolved symbol in the symbol table. template - Symbol* + Sized_symbol* add_from_incrobj(Object* obj, const char* name, const char* ver, elfcpp::Sym* sym); @@ -1578,19 +1675,6 @@ class Symbol_table // 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 @@ -1627,7 +1711,8 @@ class Symbol_table const elfcpp::Sym& sym, unsigned int st_shndx, bool is_ordinary, unsigned int orig_st_shndx, - Object*, const char* version); + Object*, const char* version, + bool is_default_version); template void @@ -1645,7 +1730,8 @@ class Symbol_table // Whether we should override a symbol, based on flags in // resolve.cc. static bool - should_override(const Symbol*, unsigned int, Defined, Object*, bool*, bool*); + should_override(const Symbol*, unsigned int, elfcpp::STT, Defined, + Object*, bool*, bool*, bool); // Report a problem in symbol resolution. static void @@ -1663,7 +1749,7 @@ class Symbol_table // 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*, Defined); + should_override_with_special(const Symbol*, elfcpp::STT, Defined); // Override a symbol with a special symbol. template