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Diffstat (limited to 'binutils-2.25/gold/reloc.h')
| -rw-r--r-- | binutils-2.25/gold/reloc.h | 899 |
1 files changed, 899 insertions, 0 deletions
diff --git a/binutils-2.25/gold/reloc.h b/binutils-2.25/gold/reloc.h new file mode 100644 index 00000000..4eca71a7 --- /dev/null +++ b/binutils-2.25/gold/reloc.h @@ -0,0 +1,899 @@ +// reloc.h -- relocate input files for gold -*- C++ -*- + +// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012 +// Free Software Foundation, Inc. +// Written by Ian Lance Taylor <iant@google.com>. + +// 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. + +#ifndef GOLD_RELOC_H +#define GOLD_RELOC_H + +#include <vector> +#ifdef HAVE_BYTESWAP_H +#include <byteswap.h> +#endif + +#include "elfcpp.h" +#include "workqueue.h" + +namespace gold +{ + +class General_options; +class Object; +class Relobj; +struct Read_relocs_data; +class Symbol; +class Layout; +class Output_data; +class Output_section; + +template<int size> +class Sized_symbol; + +template<int size, bool big_endian> +class Sized_relobj_file; + +template<int size> +class Symbol_value; + +template<int sh_type, bool dynamic, int size, bool big_endian> +class Output_data_reloc; + +// A class to read the relocations for an object file, and then queue +// up a task to see if they require any GOT/PLT/COPY relocations in +// the symbol table. + +class Read_relocs : public Task +{ + public: + // THIS_BLOCKER and NEXT_BLOCKER are passed along to a Scan_relocs + // or Gc_process_relocs task, so that they run in a deterministic + // order. + Read_relocs(Symbol_table* symtab, Layout* layout, Relobj* object, + Task_token* this_blocker, Task_token* next_blocker) + : symtab_(symtab), layout_(layout), object_(object), + this_blocker_(this_blocker), next_blocker_(next_blocker) + { } + + // The standard Task methods. + + Task_token* + is_runnable(); + + void + locks(Task_locker*); + + void + run(Workqueue*); + + std::string + get_name() const; + + private: + Symbol_table* symtab_; + Layout* layout_; + Relobj* object_; + Task_token* this_blocker_; + Task_token* next_blocker_; +}; + +// Process the relocs to figure out which sections are garbage. +// Very similar to scan relocs. + +class Gc_process_relocs : public Task +{ + public: + // THIS_BLOCKER prevents this task from running until the previous + // one is finished. NEXT_BLOCKER prevents the next task from + // running. + Gc_process_relocs(Symbol_table* symtab, Layout* layout, Relobj* object, + Read_relocs_data* rd, Task_token* this_blocker, + Task_token* next_blocker) + : symtab_(symtab), layout_(layout), object_(object), rd_(rd), + this_blocker_(this_blocker), next_blocker_(next_blocker) + { } + + ~Gc_process_relocs(); + + // The standard Task methods. + + Task_token* + is_runnable(); + + void + locks(Task_locker*); + + void + run(Workqueue*); + + std::string + get_name() const; + + private: + Symbol_table* symtab_; + Layout* layout_; + Relobj* object_; + Read_relocs_data* rd_; + Task_token* this_blocker_; + Task_token* next_blocker_; +}; + +// Scan the relocations for an object to see if they require any +// GOT/PLT/COPY relocations. + +class Scan_relocs : public Task +{ + public: + // THIS_BLOCKER prevents this task from running until the previous + // one is finished. NEXT_BLOCKER prevents the next task from + // running. + Scan_relocs(Symbol_table* symtab, Layout* layout, Relobj* object, + Read_relocs_data* rd, Task_token* this_blocker, + Task_token* next_blocker) + : symtab_(symtab), layout_(layout), object_(object), rd_(rd), + this_blocker_(this_blocker), next_blocker_(next_blocker) + { } + + ~Scan_relocs(); + + // The standard Task methods. + + Task_token* + is_runnable(); + + void + locks(Task_locker*); + + void + run(Workqueue*); + + std::string + get_name() const; + + private: + Symbol_table* symtab_; + Layout* layout_; + Relobj* object_; + Read_relocs_data* rd_; + Task_token* this_blocker_; + Task_token* next_blocker_; +}; + +// A class to perform all the relocations for an object file. + +class Relocate_task : public Task +{ + public: + Relocate_task(const Symbol_table* symtab, const Layout* layout, + Relobj* object, Output_file* of, + Task_token* input_sections_blocker, + Task_token* output_sections_blocker, Task_token* final_blocker) + : symtab_(symtab), layout_(layout), object_(object), of_(of), + input_sections_blocker_(input_sections_blocker), + output_sections_blocker_(output_sections_blocker), + final_blocker_(final_blocker) + { } + + // The standard Task methods. + + Task_token* + is_runnable(); + + void + locks(Task_locker*); + + void + run(Workqueue*); + + std::string + get_name() const; + + private: + const Symbol_table* symtab_; + const Layout* layout_; + Relobj* object_; + Output_file* of_; + Task_token* input_sections_blocker_; + Task_token* output_sections_blocker_; + Task_token* final_blocker_; +}; + +// During a relocatable link, this class records how relocations +// should be handled for a single input reloc section. An instance of +// this class is created while scanning relocs, and it is used while +// processing relocs. + +class Relocatable_relocs +{ + public: + // We use a vector of unsigned char to indicate how the input relocs + // should be handled. Each element is one of the following values. + // We create this vector when we initially scan the relocations. + enum Reloc_strategy + { + // Copy the input reloc. Don't modify it other than updating the + // r_offset field and the r_sym part of the r_info field. + RELOC_COPY, + // Copy the input reloc which is against an STT_SECTION symbol. + // Update the r_offset and r_sym part of the r_info field. Adjust + // the addend by subtracting the value of the old local symbol and + // adding the value of the new local symbol. The addend is in the + // SHT_RELA reloc and the contents of the data section do not need + // to be changed. + RELOC_ADJUST_FOR_SECTION_RELA, + // Like RELOC_ADJUST_FOR_SECTION_RELA but the addend should not be + // adjusted. + RELOC_ADJUST_FOR_SECTION_0, + // Like RELOC_ADJUST_FOR_SECTION_RELA but the contents of the + // section need to be changed. The number indicates the number of + // bytes in the addend in the section contents. + RELOC_ADJUST_FOR_SECTION_1, + RELOC_ADJUST_FOR_SECTION_2, + RELOC_ADJUST_FOR_SECTION_4, + RELOC_ADJUST_FOR_SECTION_8, + // Like RELOC_ADJUST_FOR_SECTION_4 but for unaligned relocs. + RELOC_ADJUST_FOR_SECTION_4_UNALIGNED, + // Discard the input reloc--process it completely when relocating + // the data section contents. + RELOC_DISCARD, + // An input reloc which is not discarded, but which requires + // target specific processing in order to update it. + RELOC_SPECIAL + }; + + Relocatable_relocs() + : reloc_strategies_(), output_reloc_count_(0), posd_(NULL) + { } + + // Record the number of relocs. + void + set_reloc_count(size_t reloc_count) + { this->reloc_strategies_.reserve(reloc_count); } + + // Record what to do for the next reloc. + void + set_next_reloc_strategy(Reloc_strategy strategy) + { + this->reloc_strategies_.push_back(static_cast<unsigned char>(strategy)); + if (strategy != RELOC_DISCARD) + ++this->output_reloc_count_; + } + + // Record the Output_data associated with this reloc section. + void + set_output_data(Output_data* posd) + { + gold_assert(this->posd_ == NULL); + this->posd_ = posd; + } + + // Return the Output_data associated with this reloc section. + Output_data* + output_data() const + { return this->posd_; } + + // Return what to do for reloc I. + Reloc_strategy + strategy(unsigned int i) const + { + gold_assert(i < this->reloc_strategies_.size()); + return static_cast<Reloc_strategy>(this->reloc_strategies_[i]); + } + + // Return the number of relocations to create in the output file. + size_t + output_reloc_count() const + { return this->output_reloc_count_; } + + private: + typedef std::vector<unsigned char> Reloc_strategies; + + // The strategies for the input reloc. There is one entry in this + // vector for each relocation in the input section. + Reloc_strategies reloc_strategies_; + // The number of relocations to be created in the output file. + size_t output_reloc_count_; + // The output data structure associated with this relocation. + Output_data* posd_; +}; + +// Standard relocation routines which are used on many targets. Here +// SIZE and BIG_ENDIAN refer to the target, not the relocation type. + +template<int size, bool big_endian> +class Relocate_functions +{ +private: + // Do a simple relocation with the addend in the section contents. + // VALSIZE is the size of the value. + template<int valsize> + static inline void + rel(unsigned char* view, + typename elfcpp::Swap<valsize, big_endian>::Valtype value) + { + typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; + Valtype* wv = reinterpret_cast<Valtype*>(view); + Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv); + elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value); + } + + // Like the above but for relocs at unaligned addresses. + template<int valsize> + static inline void + rel_unaligned(unsigned char* view, + typename elfcpp::Swap<valsize, big_endian>::Valtype value) + { + typedef typename elfcpp::Swap_unaligned<valsize, big_endian>::Valtype + Valtype; + Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view); + elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view, x + value); + } + + // Do a simple relocation using a Symbol_value with the addend in + // the section contents. VALSIZE is the size of the value to + // relocate. + template<int valsize> + static inline void + rel(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval) + { + typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; + Valtype* wv = reinterpret_cast<Valtype*>(view); + Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv); + x = psymval->value(object, x); + elfcpp::Swap<valsize, big_endian>::writeval(wv, x); + } + + // Like the above but for relocs at unaligned addresses. + template<int valsize> + static inline void + rel_unaligned(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval) + { + typedef typename elfcpp::Swap_unaligned<valsize, big_endian>::Valtype + Valtype; + Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view); + x = psymval->value(object, x); + elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view, x); + } + + // Do a simple relocation with the addend in the relocation. + // VALSIZE is the size of the value. + template<int valsize> + static inline void + rela(unsigned char* view, + typename elfcpp::Swap<valsize, big_endian>::Valtype value, + typename elfcpp::Swap<valsize, big_endian>::Valtype addend) + { + typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; + Valtype* wv = reinterpret_cast<Valtype*>(view); + elfcpp::Swap<valsize, big_endian>::writeval(wv, value + addend); + } + + // Do a simple relocation using a symbol value with the addend in + // the relocation. VALSIZE is the size of the value. + template<int valsize> + static inline void + rela(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + typename elfcpp::Swap<valsize, big_endian>::Valtype addend) + { + typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; + Valtype* wv = reinterpret_cast<Valtype*>(view); + Valtype x = psymval->value(object, addend); + elfcpp::Swap<valsize, big_endian>::writeval(wv, x); + } + + // Do a simple PC relative relocation with the addend in the section + // contents. VALSIZE is the size of the value. + template<int valsize> + static inline void + pcrel(unsigned char* view, + typename elfcpp::Swap<valsize, big_endian>::Valtype value, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { + typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; + Valtype* wv = reinterpret_cast<Valtype*>(view); + Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv); + elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value - address); + } + + // Like the above but for relocs at unaligned addresses. + template<int valsize> + static inline void + pcrel_unaligned(unsigned char* view, + typename elfcpp::Swap<valsize, big_endian>::Valtype value, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { + typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; + Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view); + elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view, + x + value - address); + } + + // Do a simple PC relative relocation with a Symbol_value with the + // addend in the section contents. VALSIZE is the size of the + // value. + template<int valsize> + static inline void + pcrel(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { + typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; + Valtype* wv = reinterpret_cast<Valtype*>(view); + Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv); + x = psymval->value(object, x); + elfcpp::Swap<valsize, big_endian>::writeval(wv, x - address); + } + + // Do a simple PC relative relocation with the addend in the + // relocation. VALSIZE is the size of the value. + template<int valsize> + static inline void + pcrela(unsigned char* view, + typename elfcpp::Swap<valsize, big_endian>::Valtype value, + typename elfcpp::Swap<valsize, big_endian>::Valtype addend, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { + typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; + Valtype* wv = reinterpret_cast<Valtype*>(view); + elfcpp::Swap<valsize, big_endian>::writeval(wv, value + addend - address); + } + + // Do a simple PC relative relocation with a Symbol_value with the + // addend in the relocation. VALSIZE is the size of the value. + template<int valsize> + static inline void + pcrela(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + typename elfcpp::Swap<valsize, big_endian>::Valtype addend, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { + typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; + Valtype* wv = reinterpret_cast<Valtype*>(view); + Valtype x = psymval->value(object, addend); + elfcpp::Swap<valsize, big_endian>::writeval(wv, x - address); + } + + typedef Relocate_functions<size, big_endian> This; + +public: + // Do a simple 8-bit REL relocation with the addend in the section + // contents. + static inline void + rel8(unsigned char* view, unsigned char value) + { This::template rel<8>(view, value); } + + static inline void + rel8(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval) + { This::template rel<8>(view, object, psymval); } + + // Do an 8-bit RELA relocation with the addend in the relocation. + static inline void + rela8(unsigned char* view, unsigned char value, unsigned char addend) + { This::template rela<8>(view, value, addend); } + + static inline void + rela8(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + unsigned char addend) + { This::template rela<8>(view, object, psymval, addend); } + + // Do a simple 8-bit PC relative relocation with the addend in the + // section contents. + static inline void + pcrel8(unsigned char* view, unsigned char value, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrel<8>(view, value, address); } + + static inline void + pcrel8(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrel<8>(view, object, psymval, address); } + + // Do a simple 8-bit PC relative RELA relocation with the addend in + // the reloc. + static inline void + pcrela8(unsigned char* view, unsigned char value, unsigned char addend, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrela<8>(view, value, addend, address); } + + static inline void + pcrela8(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + unsigned char addend, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrela<8>(view, object, psymval, addend, address); } + + // Do a simple 16-bit REL relocation with the addend in the section + // contents. + static inline void + rel16(unsigned char* view, elfcpp::Elf_Half value) + { This::template rel<16>(view, value); } + + static inline void + rel16(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval) + { This::template rel<16>(view, object, psymval); } + + // Do an 16-bit RELA relocation with the addend in the relocation. + static inline void + rela16(unsigned char* view, elfcpp::Elf_Half value, elfcpp::Elf_Half addend) + { This::template rela<16>(view, value, addend); } + + static inline void + rela16(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + elfcpp::Elf_Half addend) + { This::template rela<16>(view, object, psymval, addend); } + + // Do a simple 16-bit PC relative REL relocation with the addend in + // the section contents. + static inline void + pcrel16(unsigned char* view, elfcpp::Elf_Half value, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrel<16>(view, value, address); } + + static inline void + pcrel16(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrel<16>(view, object, psymval, address); } + + // Do a simple 16-bit PC relative RELA relocation with the addend in + // the reloc. + static inline void + pcrela16(unsigned char* view, elfcpp::Elf_Half value, + elfcpp::Elf_Half addend, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrela<16>(view, value, addend, address); } + + static inline void + pcrela16(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + elfcpp::Elf_Half addend, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrela<16>(view, object, psymval, addend, address); } + + // Do a simple 32-bit REL relocation with the addend in the section + // contents. + static inline void + rel32(unsigned char* view, elfcpp::Elf_Word value) + { This::template rel<32>(view, value); } + + // Like above but for relocs at unaligned addresses. + static inline void + rel32_unaligned(unsigned char* view, elfcpp::Elf_Word value) + { This::template rel_unaligned<32>(view, value); } + + static inline void + rel32(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval) + { This::template rel<32>(view, object, psymval); } + + // Like above but for relocs at unaligned addresses. + static inline void + rel32_unaligned(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval) + { This::template rel_unaligned<32>(view, object, psymval); } + + // Do an 32-bit RELA relocation with the addend in the relocation. + static inline void + rela32(unsigned char* view, elfcpp::Elf_Word value, elfcpp::Elf_Word addend) + { This::template rela<32>(view, value, addend); } + + static inline void + rela32(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + elfcpp::Elf_Word addend) + { This::template rela<32>(view, object, psymval, addend); } + + // Do a simple 32-bit PC relative REL relocation with the addend in + // the section contents. + static inline void + pcrel32(unsigned char* view, elfcpp::Elf_Word value, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrel<32>(view, value, address); } + + // Unaligned version of the above. + static inline void + pcrel32_unaligned(unsigned char* view, elfcpp::Elf_Word value, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrel_unaligned<32>(view, value, address); } + + static inline void + pcrel32(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrel<32>(view, object, psymval, address); } + + // Do a simple 32-bit PC relative RELA relocation with the addend in + // the relocation. + static inline void + pcrela32(unsigned char* view, elfcpp::Elf_Word value, + elfcpp::Elf_Word addend, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrela<32>(view, value, addend, address); } + + static inline void + pcrela32(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + elfcpp::Elf_Word addend, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrela<32>(view, object, psymval, addend, address); } + + // Do a simple 64-bit REL relocation with the addend in the section + // contents. + static inline void + rel64(unsigned char* view, elfcpp::Elf_Xword value) + { This::template rel<64>(view, value); } + + static inline void + rel64(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval) + { This::template rel<64>(view, object, psymval); } + + // Do a 64-bit RELA relocation with the addend in the relocation. + static inline void + rela64(unsigned char* view, elfcpp::Elf_Xword value, + elfcpp::Elf_Xword addend) + { This::template rela<64>(view, value, addend); } + + static inline void + rela64(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + elfcpp::Elf_Xword addend) + { This::template rela<64>(view, object, psymval, addend); } + + // Do a simple 64-bit PC relative REL relocation with the addend in + // the section contents. + static inline void + pcrel64(unsigned char* view, elfcpp::Elf_Xword value, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrel<64>(view, value, address); } + + static inline void + pcrel64(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrel<64>(view, object, psymval, address); } + + // Do a simple 64-bit PC relative RELA relocation with the addend in + // the relocation. + static inline void + pcrela64(unsigned char* view, elfcpp::Elf_Xword value, + elfcpp::Elf_Xword addend, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrela<64>(view, value, addend, address); } + + static inline void + pcrela64(unsigned char* view, + const Sized_relobj_file<size, big_endian>* object, + const Symbol_value<size>* psymval, + elfcpp::Elf_Xword addend, + typename elfcpp::Elf_types<size>::Elf_Addr address) + { This::template pcrela<64>(view, object, psymval, addend, address); } +}; + +// Integer manipulation functions used by various targets when +// performing relocations. + +template<int bits> +class Bits +{ + public: + // Sign extend an n-bit unsigned integer stored in a uint32_t into + // an int32_t. BITS must be between 1 and 32. + static inline int32_t + sign_extend32(uint32_t val) + { + gold_assert(bits > 0 && bits <= 32); + if (bits == 32) + return static_cast<int32_t>(val); + uint32_t mask = (~static_cast<uint32_t>(0)) >> (32 - bits); + val &= mask; + uint32_t top_bit = 1U << (bits - 1); + int32_t as_signed = static_cast<int32_t>(val); + if ((val & top_bit) != 0) + as_signed -= static_cast<int32_t>(top_bit * 2); + return as_signed; + } + + // Return true if VAL (stored in a uint32_t) has overflowed a signed + // value with BITS bits. + static inline bool + has_overflow32(uint32_t val) + { + gold_assert(bits > 0 && bits <= 32); + if (bits == 32) + return false; + int32_t max = (1 << (bits - 1)) - 1; + int32_t min = -(1 << (bits - 1)); + int32_t as_signed = static_cast<int32_t>(val); + return as_signed > max || as_signed < min; + } + + // Return true if VAL (stored in a uint32_t) has overflowed both a + // signed and an unsigned value. E.g., + // Bits<8>::has_signed_unsigned_overflow32 would check -128 <= VAL < + // 255. + static inline bool + has_signed_unsigned_overflow32(uint32_t val) + { + gold_assert(bits > 0 && bits <= 32); + if (bits == 32) + return false; + int32_t max = static_cast<int32_t>((1U << bits) - 1); + int32_t min = -(1 << (bits - 1)); + int32_t as_signed = static_cast<int32_t>(val); + return as_signed > max || as_signed < min; + } + + // Select bits from A and B using bits in MASK. For each n in + // [0..31], the n-th bit in the result is chosen from the n-th bits + // of A and B. A zero selects A and a one selects B. + static inline uint32_t + bit_select32(uint32_t a, uint32_t b, uint32_t mask) + { return (a & ~mask) | (b & mask); } + + // Sign extend an n-bit unsigned integer stored in a uint64_t into + // an int64_t. BITS must be between 1 and 64. + static inline int64_t + sign_extend(uint64_t val) + { + gold_assert(bits > 0 && bits <= 64); + if (bits == 64) + return static_cast<int64_t>(val); + uint64_t mask = (~static_cast<uint64_t>(0)) >> (64 - bits); + val &= mask; + uint64_t top_bit = static_cast<uint64_t>(1) << (bits - 1); + int64_t as_signed = static_cast<int64_t>(val); + if ((val & top_bit) != 0) + as_signed -= static_cast<int64_t>(top_bit * 2); + return as_signed; + } + + // Return true if VAL (stored in a uint64_t) has overflowed a signed + // value with BITS bits. + static inline bool + has_overflow(uint64_t val) + { + gold_assert(bits > 0 && bits <= 64); + if (bits == 64) + return false; + int64_t max = (static_cast<int64_t>(1) << (bits - 1)) - 1; + int64_t min = -(static_cast<int64_t>(1) << (bits - 1)); + int64_t as_signed = static_cast<int64_t>(val); + return as_signed > max || as_signed < min; + } + + // Return true if VAL (stored in a uint64_t) has overflowed both a + // signed and an unsigned value. E.g., + // Bits<8>::has_signed_unsigned_overflow would check -128 <= VAL < + // 255. + static inline bool + has_signed_unsigned_overflow64(uint64_t val) + { + gold_assert(bits > 0 && bits <= 64); + if (bits == 64) + return false; + int64_t max = static_cast<int64_t>((static_cast<uint64_t>(1) << bits) - 1); + int64_t min = -(static_cast<int64_t>(1) << (bits - 1)); + int64_t as_signed = static_cast<int64_t>(val); + return as_signed > max || as_signed < min; + } + + // Select bits from A and B using bits in MASK. For each n in + // [0..31], the n-th bit in the result is chosen from the n-th bits + // of A and B. A zero selects A and a one selects B. + static inline uint64_t + bit_select64(uint64_t a, uint64_t b, uint64_t mask) + { return (a & ~mask) | (b & mask); } +}; + +// Track relocations while reading a section. This lets you ask for +// the relocation at a certain offset, and see how relocs occur +// between points of interest. + +template<int size, bool big_endian> +class Track_relocs +{ + public: + Track_relocs() + : prelocs_(NULL), len_(0), pos_(0), reloc_size_(0) + { } + + // Initialize the Track_relocs object. OBJECT is the object holding + // the reloc section, RELOC_SHNDX is the section index of the reloc + // section, and RELOC_TYPE is the type of the reloc section + // (elfcpp::SHT_REL or elfcpp::SHT_RELA). This returns false if + // something went wrong. + bool + initialize(Object* object, unsigned int reloc_shndx, + unsigned int reloc_type); + + // Return the offset in the data section to which the next reloc + // applies. This returns -1 if there is no next reloc. + off_t + next_offset() const; + + // Return the symbol index of the next reloc. This returns -1U if + // there is no next reloc. + unsigned int + next_symndx() const; + + // Return the addend of the next reloc. This returns 0 if there is + // no next reloc. + uint64_t + next_addend() const; + + // Advance to OFFSET within the data section, and return the number + // of relocs which would be skipped. + int + advance(off_t offset); + + // Checkpoint the current position in the reloc section. + section_size_type + checkpoint() const + { return this->pos_; } + + // Reset the position to CHECKPOINT. + void + reset(section_size_type checkpoint) + { this->pos_ = checkpoint; } + + private: + // The contents of the input object's reloc section. + const unsigned char* prelocs_; + // The length of the reloc section. + section_size_type len_; + // Our current position in the reloc section. + section_size_type pos_; + // The size of the relocs in the section. + int reloc_size_; +}; + +} // End namespace gold. + +#endif // !defined(GOLD_RELOC_H) |