X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=gold%2Fmerge.h;h=fb6721d2925da70c63a5f5e2f1c785af8fec1cb6;hb=b302c308cd92656419cddc2672f43a1cbd027961;hp=ab382a1165907274f707b14d581b2478f36a94ed;hpb=6cb15b7f89d59fb61780b01ad3de2340f33c3728;p=binutils-gdb.git diff --git a/gold/merge.h b/gold/merge.h index ab382a11659..fb6721d2925 100644 --- a/gold/merge.h +++ b/gold/merge.h @@ -1,6 +1,6 @@ // merge.h -- handle section merging for gold -*- C++ -*- -// Copyright 2006, 2007 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -24,6 +24,8 @@ #define GOLD_MERGE_H #include +#include +#include #include "stringpool.h" #include "output.h" @@ -31,55 +33,223 @@ namespace gold { -// A general class for SHF_MERGE data, to hold functions shared by -// fixed-size constant data and string data. +class Merge_map; -class Output_merge_base : public Output_section_data +// 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 output_sections_ field of the Object. + +class Object_merge_map { public: - Output_merge_base(uint64_t entsize) - : Output_section_data(1), merge_map_(), entsize_(entsize) + Object_merge_map() + : first_shnum_(-1U), first_map_(), + second_shnum_(-1U), second_map_(), + section_merge_maps_() { } - // Return the output address for an input address. + ~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. MERGE_MAP is the map + // we are looking for, or NULL if we don't care. 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 - do_output_address(const Relobj* object, unsigned int shndx, off_t offset, - uint64_t output_section_address, uint64_t* poutput) const; + get_output_offset(const Merge_map*, unsigned int shndx, + section_offset_type offset, + section_offset_type *output_offset); - protected: - // Return the entry size. - uint64_t - entsize() const - { return this->entsize_; } + // Return whether this is the merge map for section SHNDX. + bool + is_merge_section_for(const Merge_map*, unsigned int shndx); - // Add a mapping from an OFFSET in input section SHNDX in object - // OBJECT to an OUTPUT_OFFSET in the output section. + // Initialize an mapping from input offsets to output addresses for + // section SHNDX. STARTING_ADDRESS is the output address of the + // merged section. + template void - add_mapping(Relobj* object, unsigned int shndx, off_t offset, - off_t output_offset); + initialize_input_to_output_map( + unsigned int shndx, + typename elfcpp::Elf_types::Elf_Addr starting_address, + Unordered_map::Elf_Addr>*); private: - // We build a mapping from OBJECT/SHNDX/OFFSET to an offset in the - // output section. - struct Merge_key + // 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 { - const Relobj* object; - unsigned int shndx; - off_t offset; + // 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; }; - struct Merge_key_less + // A less-than comparison routine for Input_merge_entry. + struct Input_merge_compare { bool - operator()(const Merge_key&, const Merge_key&) const; + operator()(const Input_merge_entry& i1, const Input_merge_entry& i2) const + { return i1.input_offset < i2.input_offset; } }; - typedef std::map Merge_map; + // A list of entries for a particular input section. + struct Input_merge_map + { + typedef std::vector Entries; + + // 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. + Entries 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 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_; +}; + +// This class manages mappings from input sections to offsets in an +// output section. This is used where input sections are merged. The +// actual data is stored in fields in Object. + +class Merge_map +{ + public: + Merge_map() + { } + + // Add a mapping for the bytes from OFFSET to OFFSET + LENGTH in the + // input section SHNDX in object OBJECT to OUTPUT_OFFSET in the + // output section. An OUTPUT_OFFSET of -1 means that the bytes are + // discarded. OUTPUT_OFFSET is not the offset from the start of the + // output section, it is the offset from the start of the merged + // data within the output section. + void + add_mapping(Relobj* object, unsigned int shndx, + section_offset_type offset, section_size_type length, + section_offset_type output_offset); + + // Return the output offset for an input address. The input address + // is at offset OFFSET in section SHNDX in OBJECT. 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. This returns the + // value stored by add_mapping, namely the offset from the start of + // the merged data within the output section. + bool + get_output_offset(const Relobj* object, unsigned int shndx, + section_offset_type offset, + section_offset_type *output_offset) const; + + // Return whether this is the merge mapping for section SHNDX in + // OBJECT. This should return true when get_output_offset would + // return true for some input offset. + bool + is_merge_section_for(const Relobj* object, unsigned int shndx) const; +}; + +// A general class for SHF_MERGE data, to hold functions shared by +// fixed-size constant data and string data. + +class Output_merge_base : public Output_section_data +{ + public: + Output_merge_base(uint64_t entsize, uint64_t addralign) + : Output_section_data(addralign), merge_map_(), entsize_(entsize) + { } + + protected: + // Return the output offset for an input offset. + bool + do_output_offset(const Relobj* object, unsigned int shndx, + section_offset_type offset, + section_offset_type* poutput) const; + + // Return whether this is the merge section for an input section. + bool + do_is_merge_section_for(const Relobj*, unsigned int shndx) const; + + // Return the entry size. + uint64_t + entsize() const + { return this->entsize_; } + + // Add a mapping from an OFFSET in input section SHNDX in object + // OBJECT to an OUTPUT_OFFSET in the output section. OUTPUT_OFFSET + // is the offset from the start of the merged data in the output + // section. + void + add_mapping(Relobj* object, unsigned int shndx, section_offset_type offset, + section_size_type length, section_offset_type output_offset) + { + this->merge_map_.add_mapping(object, shndx, offset, length, output_offset); + } + private: // A mapping from input object/section/offset to offset in output // section. Merge_map merge_map_; - // The entry size. For fixed-size constants, this is the size of // the constants. For strings, this is the size of a character. uint64_t entsize_; @@ -90,30 +260,45 @@ class Output_merge_base : public Output_section_data class Output_merge_data : public Output_merge_base { public: - Output_merge_data(uint64_t entsize) - : Output_merge_base(entsize), p_(NULL), len_(0), alc_(0), + Output_merge_data(uint64_t entsize, uint64_t addralign) + : Output_merge_base(entsize, addralign), p_(NULL), len_(0), alc_(0), + input_count_(0), hashtable_(128, Merge_data_hash(this), Merge_data_eq(this)) { } + protected: // Add an input section. bool do_add_input_section(Relobj* object, unsigned int shndx); // Set the final data size. void - do_set_address(uint64_t, off_t); + set_final_data_size(); // Write the data to the file. void do_write(Output_file*); + // Write the data to a buffer. + void + do_write_to_buffer(unsigned char*); + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** merge constants")); } + + // Print merge stats to stderr. + void + do_print_merge_stats(const char* section_name); + private: // We build a hash table of the fixed-size constants. Each constant // is stored as a pointer into the section data we are accumulating. // A key in the hash table. This is an offset in the section // contents we are building. - typedef off_t Merge_data_key; + typedef section_offset_type Merge_data_key; // Compute the hash code. To do this we need a pointer back to the // object holding the data. @@ -163,7 +348,7 @@ class Output_merge_data : public Output_merge_base const unsigned char* constant(Merge_data_key k) const { - gold_assert(k >= 0 && k < this->len_); + gold_assert(k >= 0 && k < static_cast(this->len_)); return this->p_ + k; } @@ -174,9 +359,11 @@ class Output_merge_data : public Output_merge_base // The accumulated data. unsigned char* p_; // The length of the accumulated data. - off_t len_; + section_size_type len_; // The size of the allocated buffer. - size_t alc_; + section_size_type alc_; + // The number of entries seen in input files. + size_t input_count_; // The hash table. Merge_data_hashtable hashtable_; }; @@ -188,23 +375,60 @@ template class Output_merge_string : public Output_merge_base { public: - Output_merge_string() - : Output_merge_base(sizeof(Char_type)), stringpool_(), merged_strings_() - { this->stringpool_.set_no_zero_null(); } + Output_merge_string(uint64_t addralign) + : Output_merge_base(sizeof(Char_type), addralign), stringpool_(), + merged_strings_(), input_count_(0) + { + gold_assert(addralign <= sizeof(Char_type)); + this->stringpool_.set_no_zero_null(); + } + protected: // Add an input section. bool do_add_input_section(Relobj* object, unsigned int shndx); + // Do all the final processing after the input sections are read in. + // Returns the final data size. + section_size_type + finalize_merged_data(); + // Set the final data size. void - do_set_address(uint64_t, off_t); + set_final_data_size(); // Write the data to the file. void do_write(Output_file*); + // Write the data to a buffer. + void + do_write_to_buffer(unsigned char*); + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** merge strings")); } + + // Print merge stats to stderr. + void + do_print_merge_stats(const char* section_name); + + // Writes the stringpool to a buffer. + void + stringpool_to_buffer(unsigned char* buffer, section_size_type buffer_size) + { this->stringpool_.write_to_buffer(buffer, buffer_size); } + + // Clears all the data in the stringpool, to save on memory. + void + clear_stringpool() + { this->stringpool_.clear(); } + private: + // The name of the string type, for stats. + const char* + string_name(); + // As we see input sections, we build a mapping from object, section // index and offset to strings. struct Merged_string @@ -214,13 +438,19 @@ class Output_merge_string : public Output_merge_base // The input section in the input object. unsigned int shndx; // The offset in the input section. - off_t offset; + section_offset_type offset; // The string itself, a pointer into a Stringpool. const Char_type* string; - - Merged_string(Relobj *objecta, unsigned int shndxa, off_t offseta, - const Char_type* stringa) - : object(objecta), shndx(shndxa), offset(offseta), string(stringa) + // The length of the string in bytes, including the null terminator. + size_t length; + // The key in the Stringpool. + Stringpool::Key stringpool_key; + + Merged_string(Relobj *objecta, unsigned int shndxa, + section_offset_type offseta, const Char_type* stringa, + size_t lengtha, Stringpool::Key stringpool_keya) + : object(objecta), shndx(shndxa), offset(offseta), string(stringa), + length(lengtha), stringpool_key(stringpool_keya) { } }; @@ -231,6 +461,8 @@ class Output_merge_string : public Output_merge_base // Map from a location in an input object to an entry in the // Stringpool. Merged_strings merged_strings_; + // The number of entries seen in input files. + size_t input_count_; }; } // End namespace gold.