diff options
Diffstat (limited to 'gold/merge.cc')
| -rw-r--r-- | gold/merge.cc | 200 |
1 files changed, 84 insertions, 116 deletions
diff --git a/gold/merge.cc b/gold/merge.cc index beb0906..75a3eee 100644 --- a/gold/merge.cc +++ b/gold/merge.cc @@ -30,121 +30,7 @@ namespace gold { -// For each object with merge sections, we store an Object_merge_map. -// This is used to map locations in input sections to a merged output -// section. The output section itself is not recorded here--it can be -// found in the map_to_output_ field of the Object. - -class Object_merge_map -{ - public: - Object_merge_map() - : first_shnum_(-1U), first_map_(), - second_shnum_(-1U), second_map_(), - section_merge_maps_() - { } - - ~Object_merge_map(); - - // Add a mapping for MERGE_MAP, for the bytes from OFFSET to OFFSET - // + LENGTH in the input section SHNDX to OUTPUT_OFFSET in the - // output section. An OUTPUT_OFFSET of -1 means that the bytes are - // discarded. OUTPUT_OFFSET is relative to the start of the merged - // data in the output section. - void - add_mapping(const Merge_map*, unsigned int shndx, section_offset_type offset, - section_size_type length, section_offset_type output_offset); - - // Get the output offset for an input address in MERGE_MAP. The - // input address is at offset OFFSET in section SHNDX. This sets - // *OUTPUT_OFFSET to the offset in the output section; this will be - // -1 if the bytes are not being copied to the output. This returns - // true if the mapping is known, false otherwise. *OUTPUT_OFFSET is - // relative to the start of the merged data in the output section. - bool - get_output_offset(const Merge_map*, unsigned int shndx, - section_offset_type offset, - section_offset_type *output_offset); - - private: - // Map input section offsets to a length and an output section - // offset. An output section offset of -1 means that this part of - // the input section is being discarded. - struct Input_merge_entry - { - // The offset in the input section. - section_offset_type input_offset; - // The length. - section_size_type length; - // The offset in the output section. - section_offset_type output_offset; - }; - - // A less-than comparison routine for Input_merge_entry. - struct Input_merge_compare - { - bool - operator()(const Input_merge_entry& i1, const Input_merge_entry& i2) const - { return i1.input_offset < i2.input_offset; } - }; - - // A list of entries for a particular input section. - struct Input_merge_map - { - // We store these with the Relobj, and we look them up by input - // section. It is possible to have two different merge maps - // associated with a single output section. For example, this - // happens routinely with .rodata, when merged string constants - // and merged fixed size constants are both put into .rodata. The - // output offset that we store is not the offset from the start of - // the output section; it is the offset from the start of the - // merged data in the output section. That means that the caller - // is going to add the offset of the merged data within the output - // section, which means that the caller needs to know which set of - // merged data it found the entry in. So it's not enough to find - // this data based on the input section and the output section; we - // also have to find it based on a set of merged data in the - // output section. In order to verify that we are looking at the - // right data, we store a pointer to the Merge_map here, and we - // pass in a pointer when looking at the data. If we are asked to - // look up information for a different Merge_map, we report that - // we don't have it, rather than trying a lookup and returning an - // answer which will receive the wrong offset. - const Merge_map* merge_map; - // The list of mappings. - std::vector<Input_merge_entry> entries; - // Whether the ENTRIES field is sorted by input_offset. - bool sorted; - - Input_merge_map() - : merge_map(NULL), entries(), sorted(true) - { } - }; - - // Map input section indices to merge maps. - typedef std::map<unsigned int, Input_merge_map*> Section_merge_maps; - - // Return a pointer to the Input_merge_map to use for the input - // section SHNDX, or NULL. - Input_merge_map* - get_input_merge_map(unsigned int shndx); - - // Get or make the the Input_merge_map to use for the section SHNDX - // with MERGE_MAP. - Input_merge_map* - get_or_make_input_merge_map(const Merge_map* merge_map, unsigned int shndx); - - // Any given object file will normally only have a couple of input - // sections with mergeable contents. So we keep the first two input - // section numbers inline, and push any further ones into a map. A - // value of -1U in first_shnum_ or second_shnum_ means that we don't - // have a corresponding entry. - unsigned int first_shnum_; - Input_merge_map first_map_; - unsigned int second_shnum_; - Input_merge_map second_map_; - Section_merge_maps section_merge_maps_; -}; +// Class Object_merge_map. // Destructor. @@ -261,7 +147,8 @@ Object_merge_map::get_output_offset(const Merge_map* merge_map, section_offset_type *output_offset) { Input_merge_map* map = this->get_input_merge_map(shndx); - if (map == NULL || map->merge_map != merge_map) + if (map == NULL + || (merge_map != NULL && map->merge_map != merge_map)) return false; if (!map->sorted) @@ -294,6 +181,49 @@ Object_merge_map::get_output_offset(const Merge_map* merge_map, return true; } +// Return whether this is the merge map for section SHNDX. + +inline bool +Object_merge_map::is_merge_section_for(const Merge_map* merge_map, + unsigned int shndx) +{ + Input_merge_map* map = this->get_input_merge_map(shndx); + return map != NULL && map->merge_map == merge_map; +} + +// Initialize a mapping from input offsets to output addresses. + +template<int size> +void +Object_merge_map::initialize_input_to_output_map( + unsigned int shndx, + typename elfcpp::Elf_types<size>::Elf_Addr starting_address, + Unordered_map<section_offset_type, + typename elfcpp::Elf_types<size>::Elf_Addr>* initialize_map) +{ + Input_merge_map* map = this->get_input_merge_map(shndx); + gold_assert(map != NULL); + + for (Input_merge_map::Entries::const_iterator p = map->entries.begin(); + p != map->entries.end(); + ++p) + { + section_offset_type output_offset = p->output_offset; + if (output_offset != -1) + output_offset += starting_address; + else + { + // If we see a relocation against an address we have chosen + // to discard, we relocate to zero. FIXME: We could also + // issue a warning in this case; that would require + // reporting this somehow and checking it in the routines in + // reloc.h. + output_offset = 0; + } + initialize_map->insert(std::make_pair(p->input_offset, output_offset)); + } +} + // Class Merge_map. // Add a mapping for the bytes from OFFSET to OFFSET + LENGTH in input @@ -333,6 +263,17 @@ Merge_map::get_output_offset(const Relobj* object, unsigned int shndx, output_offset); } +// Return whether this is the merge section for SHNDX in OBJECT. + +bool +Merge_map::is_merge_section_for(const Relobj* object, unsigned int shndx) const +{ + Object_merge_map* object_merge_map = object->merge_map(); + if (object_merge_map == NULL) + return false; + return object_merge_map->is_merge_section_for(this, shndx); +} + // Class Output_merge_base. // Return the output offset for an input offset. The input address is @@ -348,6 +289,15 @@ Output_merge_base::do_output_offset(const Relobj* object, return this->merge_map_.get_output_offset(object, shndx, offset, poutput); } +// Return whether this is the merge section for SHNDX in OBJECT. + +bool +Output_merge_base::do_is_merge_section_for(const Relobj* object, + unsigned int shndx) const +{ + return this->merge_map_.is_merge_section_for(object, shndx); +} + // Class Output_merge_data. // Compute the hash code for a fixed-size constant. @@ -666,4 +616,22 @@ class Output_merge_string<uint16_t>; template class Output_merge_string<uint32_t>; +#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG) +template +void +Object_merge_map::initialize_input_to_output_map<32>( + unsigned int shndx, + elfcpp::Elf_types<32>::Elf_Addr starting_address, + Unordered_map<section_offset_type, elfcpp::Elf_types<32>::Elf_Addr>*); +#endif + +#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG) +template +void +Object_merge_map::initialize_input_to_output_map<64>( + unsigned int shndx, + elfcpp::Elf_types<64>::Elf_Addr starting_address, + Unordered_map<section_offset_type, elfcpp::Elf_types<64>::Elf_Addr>*); +#endif + } // End namespace gold. |