#define GOLD_MERGE_H
#include <climits>
+#include <map>
+#include <vector>
#include "stringpool.h"
#include "output.h"
namespace gold
{
+class Merge_map;
+
+// 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. 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
+ get_output_offset(const Merge_map*, unsigned int shndx,
+ section_offset_type offset,
+ section_offset_type *output_offset);
+
+ // Return whether this is the merge map for section SHNDX.
+ bool
+ is_merge_section_for(const Merge_map*, unsigned int shndx);
+
+ // Initialize an mapping from input offsets to output addresses for
+ // section SHNDX. STARTING_ADDRESS is the output address of the
+ // merged section.
+ template<int size>
+ void
+ 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>*);
+
+ 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
+ {
+ typedef std::vector<Input_merge_entry> 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<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_;
+};
+
// 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.
// 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.
+ // 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,
// 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.
+ // 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
: 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;
- protected:
+ // 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.
+ // 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)
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