From 4d625b70fc3fb7facc7159feb8d49b78ac6641f9 Mon Sep 17 00:00:00 2001 From: Cary Coutant Date: Fri, 11 Dec 2015 07:43:59 -0800 Subject: Refactor gold to enable support for MIPS-64 relocation format. For MIPS-64, the r_info field in the relocation format is replaced by several individual fields, including r_sym and r_type. To enable support for this format, I've refactored target-independent code to remove almost all uses of the r_info field. (I've left alone a couple of routines used only for incremental linking, which I can update if/when the MIPS target adds support for incremental linking.) For routines that are already templated on a Classify_reloc class (namely, gc_process_relocs, relocate_section, and relocate_relocs), I've extended the Classify_reloc interface to include sh_type (which no longer needs to be a separate template parameter) as well as get_r_sym() and get_r_type() methods for extracting the r_sym and r_type fields. For scan_relocatable_relocs, I've extended the Default_scan_relocatable_relocs class by converting it to a class template with Classify_reloc as a template parameter. For the remaining routines that need to access r_sym, I've added a virtual Target::get_r_sym() method with an override for the MIPS target. In elfcpp, I've added Mips64_rel, etc., accessor classes and corresponding internal data structures. The MIPS target uses these new classes within its own Mips_classify_reloc class. The Mips64_ accessor classes also expose the r_ssym, r_type2, and r_type3 fields from the relocation. These changes should be functionally the same for all but the MIPS target. elfcpp/ * elfcpp.h (Mips64_rel, Mips64_rel_write): New classes. (Mips64_rela, Mips64_rela_write): New classes. * elfcpp_internal.h (Mips64_rel_data, Mips64_rela_data): New structs. gold/ * gc.h (get_embedded_addend_size): Remove sh_type parameter. (gc_process_relocs): Remove sh_type template parameter. Use Classify_reloc to access r_sym, r_type, and r_addend fields. * object.h (Sized_relobj_file::split_stack_adjust): Add target parameter. (Sized_relobj_file::split_stack_adjust_reltype): Likewise. * reloc-types.h (Reloc_types::copy_reloc_addend): (SHT_REL and SHT_RELA specializations) Remove. * reloc.cc (Emit_relocs_strategy): Rename and move to target-reloc.h. (Sized_relobj_file::emit_relocs_scan): Call Target::emit_relocs_scan(). (Sized_relobj_file::emit_relocs_scan_reltype): Remove. (Sized_relobj_file::split_stack_adjust): Add target parameter. Adjust all callers. (Sized_relobj_file::split_stack_adjust_reltype): Likewise. Call Target::get_r_sym() to get r_sym field from relocations. (Track_relocs::next_symndx): Call Target::get_r_sym(). * target-reloc.h (scan_relocs): Remove sh_type template parameter; add Classify_reloc template parameter. Use for accessing r_sym and r_type. (relocate_section): Likewise. (Default_classify_reloc): New class (renamed and moved from reloc.cc). (Default_scan_relocatable_relocs): Remove sh_type template parameter. (Default_scan_relocatable_relocs::Reltype): New typedef. (Default_scan_relocatable_relocs::reloc_size): New const. (Default_scan_relocatable_relocs::sh_type): New const. (Default_scan_relocatable_relocs::get_r_sym): New method. (Default_scan_relocatable_relocs::get_r_type): New method. (Default_emit_relocs_strategy): New class. (scan_relocatable_relocs): Replace sh_type template parameter with Scan_relocatable_relocs class. Use it to access r_sym and r_type fields. (relocate_relocs): Replace sh_type template parameter with Classify_reloc class. Use it to access r_sym and r_type fields. * target.h (Target::is_call_to_non_split): Replace r_type parameter with pointer to relocation. Adjust all callers. (Target::do_is_call_to_non_split): Likewise. (Target::emit_relocs_scan): New virtual method. (Sized_target::get_r_sym): New virtual method. * target.cc (Target::do_is_call_to_non_split): Replace r_type parameter with pointer to relocation. * aarch64.cc (Target_aarch64::emit_relocs_scan): New method. (Target_aarch64::Relocatable_size_for_reloc): Remove. (Target_aarch64::gc_process_relocs): Use Default_classify_reloc. (Target_aarch64::scan_relocs): Likewise. (Target_aarch64::relocate_section): Likewise. (Target_aarch64::Relocatable_size_for_reloc::get_size_for_reloc): Remove. (Target_aarch64::scan_relocatable_relocs): Use Default_classify_reloc. (Target_aarch64::relocate_relocs): Use Default_classify_reloc. * arm.cc (Target_arm::Arm_scan_relocatable_relocs): Remove sh_type template parameter. (Target_arm::emit_relocs_scan): New method. (Target_arm::Relocatable_size_for_reloc): Replace with... (Target_arm::Classify_reloc): ...this. (Target_arm::gc_process_relocs): Use Classify_reloc. (Target_arm::scan_relocs): Likewise. (Target_arm::relocate_section): Likewise. (Target_arm::scan_relocatable_relocs): Likewise. (Target_arm::relocate_relocs): Likewise. * i386.cc (Target_i386::emit_relocs_scan): New method. (Target_i386::Relocatable_size_for_reloc): Replace with... (Target_i386::Classify_reloc): ...this. (Target_i386::gc_process_relocs): Use Classify_reloc. (Target_i386::scan_relocs): Likewise. (Target_i386::relocate_section): Likewise. (Target_i386::scan_relocatable_relocs): Likewise. (Target_i386::relocate_relocs): Likewise. * mips.cc (Mips_scan_relocatable_relocs): Remove sh_type template parameter. (Mips_reloc_types): New class template. (Mips_classify_reloc): New class template. (Target_mips::Reltype): New typedef. (Target_mips::Relatype): New typedef. (Target_mips::emit_relocs_scan): New method. (Target_mips::get_r_sym): New method. (Target_mips::Relocatable_size_for_reloc): Replace with Mips_classify_reloc. (Target_mips::copy_reloc): Use Mips_classify_reloc. (Target_mips::gc_process_relocs): Likewise. (Target_mips::scan_relocs): Likewise. (Target_mips::relocate_section): Likewise. (Target_mips::scan_relocatable_relocs): Likewise. (Target_mips::relocate_relocs): Likewise. (mips_get_size_for_reloc): New function, factored out from Relocatable_size_for_reloc::get_size_for_reloc. (Target_mips::Scan::local): Use Mips_classify_reloc. (Target_mips::Scan::global): Likewise. (Target_mips::Relocate::relocate): Likewise. * powerpc.cc (Target_powerpc::emit_relocs_scan): New method. (Target_powerpc::Relocatable_size_for_reloc): Remove. (Target_powerpc::gc_process_relocs): Use Default_classify_reloc. (Target_powerpc::scan_relocs): Likewise. (Target_powerpc::relocate_section): Likewise. (Powerpc_scan_relocatable_reloc): Convert to class template. (Powerpc_scan_relocatable_reloc::Reltype): New typedef. (Powerpc_scan_relocatable_reloc::reloc_size): New const. (Powerpc_scan_relocatable_reloc::sh_type): New const. (Powerpc_scan_relocatable_reloc::get_r_sym): New method. (Powerpc_scan_relocatable_reloc::get_r_type): New method. (Target_powerpc::scan_relocatable_relocs): Use Powerpc_scan_relocatable_reloc. (Target_powerpc::relocate_relocs): Use Default_classify_reloc. * s390.cc (Target_s390::emit_relocs_scan): New method. (Target_s390::Relocatable_size_for_reloc): Remove. (Target_s390::gc_process_relocs): Use Default_classify_reloc. (Target_s390::scan_relocs): Likewise. (Target_s390::relocate_section): Likewise. (Target_s390::Relocatable_size_for_reloc::get_size_for_reloc): Remove. (Target_s390::scan_relocatable_relocs): Use Default_classify_reloc. (Target_s390::relocate_relocs): Use Default_classify_reloc. * sparc.cc (Target_sparc::emit_relocs_scan): New method. (Target_sparc::Relocatable_size_for_reloc): Remove. (Target_sparc::gc_process_relocs): Use Default_classify_reloc. (Target_sparc::scan_relocs): Likewise. (Target_sparc::relocate_section): Likewise. (Target_sparc::Relocatable_size_for_reloc::get_size_for_reloc): Remove. (Target_sparc::scan_relocatable_relocs): Use Default_classify_reloc. (Target_sparc::relocate_relocs): Use Default_classify_reloc. * tilegx.cc (Target_tilegx::emit_relocs_scan): New method. (Target_tilegx::Relocatable_size_for_reloc): Remove. (Target_tilegx::gc_process_relocs): Use Default_classify_reloc. (Target_tilegx::scan_relocs): Likewise. (Target_tilegx::relocate_section): Likewise. (Target_tilegx::Relocatable_size_for_reloc::get_size_for_reloc): Remove. (Target_tilegx::scan_relocatable_relocs): Use Default_classify_reloc. (Target_tilegx::relocate_relocs): Use Default_classify_reloc. * x86_64.cc (Target_x86_64::emit_relocs_scan): New method. (Target_x86_64::Relocatable_size_for_reloc): Remove. (Target_x86_64::gc_process_relocs): Use Default_classify_reloc. (Target_x86_64::scan_relocs): Likewise. (Target_x86_64::relocate_section): Likewise. (Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc): Remove. (Target_x86_64::scan_relocatable_relocs): Use Default_classify_reloc. (Target_x86_64::relocate_relocs): Use Default_classify_reloc. * testsuite/testfile.cc (Target_test::emit_relocs_scan): New method. --- gold/target.h | 37 +++++++++++++++++++++++++++++++++---- 1 file changed, 33 insertions(+), 4 deletions(-) (limited to 'gold/target.h') diff --git a/gold/target.h b/gold/target.h index 27e8a2e..c0f24ee 100644 --- a/gold/target.h +++ b/gold/target.h @@ -321,13 +321,13 @@ class Target ehframe_datarel_base() const { return this->do_ehframe_datarel_base(); } - // Return true if a reference to SYM from a reloc of type R_TYPE + // Return true if a reference to SYM from a reloc at *PRELOC // means that the current function may call an object compiled // without -fsplit-stack. SYM is known to be defined in an object // compiled without -fsplit-stack. bool - is_call_to_non_split(const Symbol* sym, unsigned int r_type) const - { return this->do_is_call_to_non_split(sym, r_type); } + is_call_to_non_split(const Symbol* sym, const unsigned char* preloc) const + { return this->do_is_call_to_non_split(sym, preloc); } // A function starts at OFFSET in section SHNDX in OBJECT. That // function was compiled with -fsplit-stack, but it refers to a @@ -661,7 +661,7 @@ class Target // default implementation is that any function not defined by the // ABI is a call to a non-split function. virtual bool - do_is_call_to_non_split(const Symbol* sym, unsigned int) const; + do_is_call_to_non_split(const Symbol* sym, const unsigned char*) const; // Virtual function which may be overridden by the child class. virtual void @@ -926,6 +926,22 @@ class Sized_target : public Target const unsigned char* plocal_symbols, Relocatable_relocs*) = 0; + // Scan the relocs for --emit-relocs. The parameters are + // like scan_relocatable_relocs. + virtual void + emit_relocs_scan(Symbol_table* symtab, + Layout* layout, + Sized_relobj_file* object, + unsigned int data_shndx, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + bool needs_special_offset_handling, + size_t local_symbol_count, + const unsigned char* plocal_syms, + Relocatable_relocs* rr) = 0; + // Emit relocations for a section during a relocatable link, and for // --emit-relocs. The parameters are like relocate_section, with // additional parameters for the view of the output reloc section. @@ -1084,6 +1100,19 @@ class Sized_target : public Target dst_obj, dst_shndx, dst_off); } + // Return the r_sym field from a relocation. + // Most targets can use the default version of this routine, + // but some targets have a non-standard r_info field, and will + // need to provide a target-specific version. + virtual unsigned int + get_r_sym(const unsigned char* preloc) const + { + // Since REL and RELA relocs share the same structure through + // the r_info field, we can just use REL here. + elfcpp::Rel rel(preloc); + return elfcpp::elf_r_sym(rel.get_r_info()); + } + protected: Sized_target(const Target::Target_info* pti) : Target(pti) -- cgit v1.1