#ifndef GOLD_RELOC_H
#define GOLD_RELOC_H
+#include <byteswap.h>
+
#include "workqueue.h"
namespace gold
{
+class General_options;
+class Relobj;
+class Read_relocs_data;
+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.
+
+class Read_relocs : public Task
+{
+ public:
+ // SYMTAB_LOCK is used to lock the symbol table. BLOCKER should be
+ // unblocked when the Scan_relocs task completes.
+ Read_relocs(const General_options& options, Symbol_table* symtab,
+ Layout* layout, Relobj* object, Task_token* symtab_lock,
+ Task_token* blocker)
+ : options_(options), symtab_(symtab), layout_(layout), object_(object),
+ symtab_lock_(symtab_lock), blocker_(blocker)
+ { }
+
+ // The standard Task methods.
+
+ Is_runnable_type
+ is_runnable(Workqueue*);
+
+ Task_locker*
+ locks(Workqueue*);
+
+ void
+ run(Workqueue*);
+
+ private:
+ const General_options& options_;
+ Symbol_table* symtab_;
+ Layout* layout_;
+ Relobj* object_;
+ Task_token* symtab_lock_;
+ Task_token* blocker_;
+};
+
+// Scan the relocations for an object to see if they require any
+// GOT/PLT/COPY relocations.
+
+class Scan_relocs : public Task
+{
+ public:
+ // SYMTAB_LOCK is used to lock the symbol table. BLOCKER should be
+ // unblocked when the task completes.
+ Scan_relocs(const General_options& options, Symbol_table* symtab,
+ Layout* layout, Relobj* object, Read_relocs_data* rd,
+ Task_token* symtab_lock, Task_token* blocker)
+ : options_(options), symtab_(symtab), layout_(layout), object_(object),
+ rd_(rd), symtab_lock_(symtab_lock), blocker_(blocker)
+ { }
+
+ // The standard Task methods.
+
+ Is_runnable_type
+ is_runnable(Workqueue*);
+
+ Task_locker*
+ locks(Workqueue*);
+
+ void
+ run(Workqueue*);
+
+ private:
+ class Scan_relocs_locker;
+
+ const General_options& options_;
+ Symbol_table* symtab_;
+ Layout* layout_;
+ Relobj* object_;
+ Read_relocs_data* rd_;
+ Task_token* symtab_lock_;
+ Task_token* blocker_;
+};
+
+// A class to perform all the relocations for an object file.
+
class Relocate_task : public Task
{
public:
Relocate_task(const General_options& options, const Symbol_table* symtab,
- const Stringpool* sympool, Object* object, Output_file* of,
+ const Layout* layout, Relobj* object, Output_file* of,
Task_token* final_blocker)
- : options_(options), symtab_(symtab), sympool_(sympool), object_(object),
+ : options_(options), symtab_(symtab), layout_(layout), object_(object),
of_(of), final_blocker_(final_blocker)
{ }
const General_options& options_;
const Symbol_table* symtab_;
- const Stringpool* sympool_;
- Object* object_;
+ const Layout* layout_;
+ Relobj* object_;
Output_file* of_;
Task_token* final_blocker_;
};
+// Standard relocation routines which are used on many targets. Here
+// SIZE and BIG_ENDIAN refer to the target, not the relocation type.
+
+template<int size, bool big_endian>
+class Relocate_functions
+{
+private:
+ // Do a simple relocation with the addend in the section contents.
+ // VALSIZE is the size of the value.
+ template<int valsize>
+ static inline void
+ rel(unsigned char* view,
+ typename elfcpp::Swap<valsize, big_endian>::Valtype value)
+ {
+ typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
+ elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value);
+ }
+
+ // Do a simple PC relative relocation with the addend in the section
+ // contents. VALSIZE is the size of the value.
+ template<int valsize>
+ static inline void
+ pcrel(unsigned char* view,
+ typename elfcpp::Swap<valsize, big_endian>::Valtype value,
+ typename elfcpp::Elf_types<size>::Elf_Addr address)
+ {
+ typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv);
+ elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value - address);
+ }
+
+ typedef Relocate_functions<size, big_endian> This;
+
+public:
+ // Do a simple 8-bit REL relocation with the addend in the object
+ // file data.
+ static inline void
+ rel8(unsigned char* view, unsigned char value)
+ {
+ This::template rel<8>(view, value);
+ }
+
+ // Do a simple 8-bit PC relative relocation with the addend in the
+ // object file data.
+ static inline void
+ pcrel8(unsigned char* view, unsigned char value,
+ typename elfcpp::Elf_types<size>::Elf_Addr address)
+ {
+ This::template pcrel<8>(view, value, address);
+ }
+
+ // Do a simple 16-bit REL relocation with the addend in the object
+ // file data.
+ static inline void
+ rel16(unsigned char* view, elfcpp::Elf_Half value)
+ {
+ This::template rel<16>(view, value);
+ }
+
+ // Do a simple 32-bit PC relative REL relocation with the addend in
+ // the object file data.
+ static inline void
+ pcrel16(unsigned char* view, elfcpp::Elf_Word value,
+ typename elfcpp::Elf_types<size>::Elf_Addr address)
+ {
+ This::template pcrel<16>(view, value, address);
+ }
+
+ // Do a simple 32-bit REL relocation with the addend in the section
+ // contents.
+ static inline void
+ rel32(unsigned char* view, elfcpp::Elf_Word value)
+ {
+ This::template rel<32>(view, value);
+ }
+
+ // Do a simple 32-bit PC relative REL relocation with the addend in
+ // the section contents.
+ static inline void
+ pcrel32(unsigned char* view, elfcpp::Elf_Word value,
+ typename elfcpp::Elf_types<size>::Elf_Addr address)
+ {
+ This::template pcrel<32>(view, value, address);
+ }
+
+ // Do a simple 64-bit REL relocation with the addend in the section
+ // contents.
+ static inline void
+ rel64(unsigned char* view, elfcpp::Elf_Xword value)
+ {
+ This::template rel<64>(view, value);
+ }
+
+ // Do a simple 64-bit PC relative REL relocation with the addend in
+ // the section contents.
+ static inline void
+ pcrel64(unsigned char* view, elfcpp::Elf_Xword value,
+ typename elfcpp::Elf_types<size>::Elf_Addr address)
+ {
+ 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,
+ 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.
#endif // !defined(GOLD_RELOC_H)
projects / deliverable / binutils-gdb.git / blobdiff