X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gold%2Fsymtab.h;h=913ccdebca1c64d19bdd36cd53e68c3b3140632f;hb=40c75bc8b07abc5d5774ea1c439b69c96e7fd485;hp=87e70990d1dc4c54273bcbe8852f7867ed277518;hpb=6fa2a40bf45fcc738eb580a6b644ac74b42c2d6a;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/symtab.h b/gold/symtab.h index 87e70990d1..913ccdebca 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) 2006-2020 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -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 @@ -146,7 +159,7 @@ class Symbol object() const { gold_assert(this->source_ == FROM_OBJECT); - return this->u_.from_object.object; + return this->u1_.object; } // Return the index of the section in the input relocatable or @@ -156,7 +169,7 @@ class Symbol { gold_assert(this->source_ == FROM_OBJECT); *is_ordinary = this->is_ordinary_shndx_; - return this->u_.from_object.shndx; + return this->u2_.shndx; } // Return the output data section with which this symbol is @@ -166,7 +179,7 @@ class Symbol output_data() const { gold_assert(this->source_ == IN_OUTPUT_DATA); - return this->u_.in_output_data.output_data; + return this->u1_.output_data; } // If this symbol was defined with respect to an output data @@ -175,7 +188,7 @@ class Symbol offset_is_from_end() const { gold_assert(this->source_ == IN_OUTPUT_DATA); - return this->u_.in_output_data.offset_is_from_end; + return this->u2_.offset_is_from_end; } // Return the output segment with which this symbol is associated, @@ -185,7 +198,7 @@ class Symbol output_segment() const { gold_assert(this->source_ == IN_OUTPUT_SEGMENT); - return this->u_.in_output_segment.output_segment; + return this->u1_.output_segment; } // If this symbol was defined with respect to an output segment, @@ -194,7 +207,7 @@ class Symbol offset_base() const { gold_assert(this->source_ == IN_OUTPUT_SEGMENT); - return this->u_.in_output_segment.offset_base; + return this->u2_.offset_base; } // Return the symbol binding. @@ -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. @@ -305,6 +329,11 @@ class Symbol set_in_reg() { this->in_reg_ = true; } + // Forget this symbol was seen in a regular object. + void + clear_in_reg() + { this->in_reg_ = false; } + // Return whether this symbol has been seen in a dynamic object. bool in_dyn() const @@ -315,6 +344,11 @@ class Symbol set_in_dyn() { this->in_dyn_ = true; } + // Return whether this symbol is defined in a dynamic object. + bool + from_dyn() const + { return this->source_ == FROM_OBJECT && this->object()->is_dynamic(); } + // 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.) @@ -504,7 +538,22 @@ 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 +572,6 @@ 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 +581,9 @@ 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 +615,11 @@ 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 +681,10 @@ 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 +721,8 @@ 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 +814,18 @@ 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 @@ -797,17 +865,56 @@ 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_); } + + // Return true if this symbol is protected in a shared object. + // This is not the same as checking if visibility() == elfcpp::STV_PROTECTED, + // because the visibility_ field reflects the symbol's visibility from + // outside the shared object. + bool + is_protected() const + { return this->is_protected_; } + + // Mark this symbol as protected in a shared object. + void + set_is_protected() + { this->is_protected_ = true; } + + // Return state of PowerPC64 ELFv2 specific flag. + bool + non_zero_localentry() const + { return this->non_zero_localentry_; } + + // Set PowerPC64 ELFv2 specific flag. + void + set_non_zero_localentry() + { this->non_zero_localentry_ = true; } + + // Completely override existing symbol. Everything bar name_, + // version_, and is_forced_local_ flag are copied. version_ is + // cleared if from->version_ is clear. Returns true if this symbol + // should be forced local. + bool + clone(const Symbol* from); + protected: // Instances of this class should always be created at a specific // size. Symbol() - { memset(this, 0, sizeof *this); } + { memset(static_cast(this), 0, sizeof *this); } // Initialize the general fields. void @@ -828,7 +935,8 @@ 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 +944,14 @@ 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 @@ -881,38 +990,38 @@ class Symbol union { - // This struct is used if SOURCE_ == FROM_OBJECT. - struct - { - // Object in which symbol is defined, or in which it was first - // seen. - Object* object; - // Section number in object_ in which symbol is defined. - unsigned int shndx; - } from_object; - - // This struct is used if SOURCE_ == IN_OUTPUT_DATA. - struct - { - // Output_data in which symbol is defined. Before - // Layout::finalize the symbol's value is an offset within the - // Output_data. - Output_data* output_data; - // True if the offset is from the end, false if the offset is - // from the beginning. - bool offset_is_from_end; - } in_output_data; - - // This struct is used if SOURCE_ == IN_OUTPUT_SEGMENT. - struct - { - // Output_segment in which the symbol is defined. Before - // Layout::finalize the symbol's value is an offset. - Output_segment* output_segment; - // The base to use for the offset before Layout::finalize. - Segment_offset_base offset_base; - } in_output_segment; - } u_; + // This is used if SOURCE_ == FROM_OBJECT. + // Object in which symbol is defined, or in which it was first + // seen. + Object* object; + + // This is used if SOURCE_ == IN_OUTPUT_DATA. + // Output_data in which symbol is defined. Before + // Layout::finalize the symbol's value is an offset within the + // Output_data. + Output_data* output_data; + + // This is used if SOURCE_ == IN_OUTPUT_SEGMENT. + // Output_segment in which the symbol is defined. Before + // Layout::finalize the symbol's value is an offset. + Output_segment* output_segment; + } u1_; + + union + { + // This is used if SOURCE_ == FROM_OBJECT. + // Section number in object in which symbol is defined. + unsigned int shndx; + + // This is used if SOURCE_ == IN_OUTPUT_DATA. + // True if the offset is from the end, false if the offset is + // from the beginning. + bool offset_is_from_end; + + // This is used if SOURCE_ == IN_OUTPUT_SEGMENT. + // The base to use for the offset before Layout::finalize. + Segment_offset_base offset_base; + } u2_; // The index of this symbol in the output file. If the symbol is // not going into the output file, this value is -1U. This field @@ -926,16 +1035,16 @@ class Symbol // non-zero value during Layout::finalize. unsigned int dynsym_index_; - // The GOT section entries for this symbol. 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, then this is the // offset from the start of the PLT section. This is -1U if there // is no PLT entry. unsigned int plt_offset_; + // The GOT section entries for this symbol. 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_; + // Symbol type (bits 0 to 3). elfcpp::STT type_ : 4; // Symbol binding (bits 4 to 7). @@ -977,11 +1086,16 @@ class Symbol // True if this symbol was forced to local visibility by a version // script (bit 28). bool is_forced_local_ : 1; - // True if the field u_.from_object.shndx is an ordinary section + // True if the field u2_.shndx is an ordinary section // 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 +1103,16 @@ 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; + // True if this symbol has protected visibility in a shared object (bit 35). + // The visibility_ field will be STV_DEFAULT in this case because we + // must treat it as such from outside the shared object. + bool is_protected_ : 1; + // Used by PowerPC64 ELFv2 to track st_other localentry (bit 36). + bool non_zero_localentry_ : 1; }; // The parts of a symbol which are size specific. Using a template @@ -1020,25 +1142,25 @@ 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 - init_undefined(const char* name, const char* version, elfcpp::STT, - elfcpp::STB, elfcpp::STV, unsigned char nonvis); + init_undefined(const char* name, const char* version, Value_type value, + elfcpp::STT, elfcpp::STB, elfcpp::STV, unsigned char nonvis); // Override existing symbol. template @@ -1077,6 +1199,13 @@ class Sized_symbol : public Symbol void allocate_common(Output_data*, Value_type value); + // Completely override existing symbol. Everything bar name_, + // version_, and is_forced_local_ flag are copied. version_ is + // cleared if from->version_ is clear. Returns true if this symbol + // should be forced local. + bool + clone(const Sized_symbol* from); + private: Sized_symbol(const Sized_symbol&); Sized_symbol& operator=(const Sized_symbol&); @@ -1161,6 +1290,35 @@ 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); + } +}; + +// 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_hash +{ + size_t operator()(const Symbol_location& loc) const + { return reinterpret_cast(loc.object) ^ loc.offset ^ loc.shndx; } +}; + // 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 +1408,9 @@ 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 +1438,7 @@ 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 +1452,9 @@ 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. @@ -1341,7 +1501,7 @@ class Symbol_table // 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); @@ -1384,6 +1544,12 @@ class Symbol_table define_symbols(const Layout*, int count, const Define_symbol_in_segment*, bool only_if_ref); + // Add a target-specific global symbol. + // (Used by SPARC backend to add STT_SPARC_REGISTER symbols.) + void + add_target_global_symbol(Symbol* sym) + { this->target_symbols_.push_back(sym); } + // 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. @@ -1414,6 +1580,10 @@ class Symbol_table saw_undefined() const { return this->saw_undefined_; } + void + set_has_gnu_output() + { this->has_gnu_output_ = true; } + // Allocate the common symbols void allocate_commons(Layout*, Mapfile*); @@ -1454,12 +1624,13 @@ class Symbol_table 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 + // global dynamic symbol. Return the count of forced-local symbols in + // *PFORCED_LOCAL_COUNT. 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(unsigned int index, std::vector*, - Stringpool*, Versions*); + set_dynsym_indexes(unsigned int index, unsigned int* pforced_local_count, + 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, @@ -1544,6 +1715,15 @@ class Symbol_table version_script() const { return version_script_; } + // Completely override existing symbol. + template + void + clone(Sized_symbol* to, const Sized_symbol* from) + { + if (to->clone(from)) + this->force_local(to); + } + private: Symbol_table(const Symbol_table&); Symbol_table& operator=(const Symbol_table&); @@ -1574,29 +1754,6 @@ class Symbol_table typedef Unordered_map Symbol_table_type; - // 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; } - }; - typedef Unordered_map > Odr_map; @@ -1627,7 +1784,8 @@ 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 +1803,8 @@ 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 +1822,7 @@ 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 @@ -1680,8 +1839,9 @@ class Symbol_table template Sized_symbol* define_special_symbol(const char** pname, const char** pversion, - bool only_if_ref, Sized_symbol** poldsym, - bool* resolve_oldsym); + bool only_if_ref, elfcpp::STV visibility, + Sized_symbol** poldsym, + bool* resolve_oldsym, bool is_forced_local); // Define a symbol in an Output_data, sized version. template @@ -1819,10 +1979,14 @@ class Symbol_table 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. + // The index of the first global dynamic symbol (including + // forced-local symbols). unsigned int first_dynamic_global_index_; - // The number of global dynamic symbols, or 0 if none. + // The number of global dynamic symbols (including forced-local symbols), + // or 0 if none. unsigned int dynamic_count_; + // Set if a STT_GNU_IFUNC or STB_GNU_UNIQUE symbol will be output. + bool has_gnu_output_; // The symbol hash table. Symbol_table_type table_; // A pool of symbol names. This is used for all global symbols. @@ -1865,6 +2029,8 @@ class Symbol_table const Version_script_info& version_script_; Garbage_collection* gc_; Icf* icf_; + // Target-specific symbols, if any. + std::vector target_symbols_; }; // We inline get_sized_symbol for efficiency.