// merge.cc -- handle section merging for gold
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
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.
// Get the output offset for an input address.
-inline bool
+bool
Object_merge_map::get_output_offset(const Merge_map* merge_map,
unsigned int shndx,
section_offset_type input_offset,
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)
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
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
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.
this->add_mapping(p->object, p->shndx, p->offset, p->length, offset);
}
- // Save some memory.
+ // Save some memory. This also ensures that this function will work
+ // if called twice, as may happen if Layout::set_segment_offsets
+ // finds a better alignment.
this->merged_strings_.clear();
return this->stringpool_.get_strtab_size();
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.
projects / deliverable / binutils-gdb.git / blobdiff