summaryrefslogtreecommitdiff
path: root/gold/reloc.h
diff options
context:
space:
mode:
Diffstat (limited to 'gold/reloc.h')
-rw-r--r--gold/reloc.h95
1 files changed, 94 insertions, 1 deletions
diff --git a/gold/reloc.h b/gold/reloc.h
index 7829440bf49..1edaa579cee 100644
--- a/gold/reloc.h
+++ b/gold/reloc.h
@@ -17,6 +17,12 @@ class Stringpool;
class Symbol;
class Layout;
+template<int size>
+class Sized_symbol;
+
+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.
@@ -229,12 +235,99 @@ public:
{
This::template pcrel<64>(view, value, address);
}
+};
+
+// We try to avoid COPY relocations when possible. A COPY relocation
+// may be required when an executable refers to a variable defined in
+// a shared library. COPY relocations are problematic because they
+// tie the executable to the exact size of the variable in the shared
+// library. We can avoid them if all the references to the variable
+// are in a writeable section. In that case we can simply use dynamic
+// relocations. However, when scanning relocs, we don't know when we
+// see the relocation whether we will be forced to use a COPY
+// relocation or not. So we have to save the relocation during the
+// reloc scanning, and then emit it as a dynamic relocation if
+// necessary. This class implements that. It is used by the target
+// specific code.
+
+template<int size, bool big_endian>
+class Copy_relocs
+{
+ public:
+ Copy_relocs()
+ : entries_()
+ { }
// Return whether we need a COPY reloc for a reloc against GSYM,
// which is being applied to section SHNDX in OBJECT.
static bool
need_copy_reloc(const General_options*, Relobj* object, unsigned int shndx,
- Symbol* gsym);
+ Sized_symbol<size>* gsym);
+
+ // Save a Rel against SYM for possible emission later. SHNDX is the
+ // index of the section to which the reloc is being applied.
+ void
+ save(Symbol* sym, Relobj*, unsigned int shndx,
+ const elfcpp::Rel<size, big_endian>&);
+
+ // Save a Rela against SYM for possible emission later.
+ void
+ save(Symbol* sym, Relobj*, unsigned int shndx,
+ const elfcpp::Rela<size, big_endian>&);
+
+ // Return whether there are any relocs to emit. This also discards
+ // entries which need not be emitted.
+ bool
+ any_to_emit();
+
+ // Emit relocs for each symbol which did not get a COPY reloc (i.e.,
+ // is still defined in the dynamic object).
+ template<int sh_type>
+ void
+ emit(Output_data_reloc<sh_type, true, size, big_endian>*);
+
+ private:
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
+ typedef typename elfcpp::Elf_types<size>::Elf_Addr Addend;
+
+ // This POD class holds the entries we are saving.
+ class Copy_reloc_entry
+ {
+ public:
+ Copy_reloc_entry(Symbol* sym, unsigned int reloc_type,
+ Relobj* relobj, unsigned int shndx,
+ Address address, Addend addend)
+ : sym_(sym), reloc_type_(reloc_type), relobj_(relobj),
+ shndx_(shndx), address_(address), addend_(addend)
+ { }
+
+ // Return whether we should emit this reloc. If we should not
+ // emit, we clear it.
+ bool
+ should_emit();
+
+ // Emit this reloc.
+
+ void
+ emit(Output_data_reloc<elfcpp::SHT_REL, true, size, big_endian>*);
+
+ void
+ emit(Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>*);
+
+ private:
+ Symbol* sym_;
+ unsigned int reloc_type_;
+ Relobj* relobj_;
+ unsigned int shndx_;
+ Address address_;
+ Addend addend_;
+ };
+
+ // A list of relocs to be saved.
+ typedef std::vector<Copy_reloc_entry> Copy_reloc_entries;
+
+ // The list of relocs we are saving.
+ Copy_reloc_entries entries_;
};
} // End namespace gold.