Mips: Omit empty objects for merging processor-specific data.

gold/
	* mips.cc (Mips_relobj::merge_processor_specific_data_): New data
	member.
	(Mips_relobj::merge_processor_specific_data): New method.
	(Mips_relobj::do_read_symbols): Set merge_processor_specific_data_
	to false, only if the input file is a binary or if object has no
	contents except the section name string table and an empty symbol
	table with the undefined symbol.
	(Target_mips::do_finalize_sections): Refactor.  Skip empty object files
	for merging processor-specific data.
This commit is contained in:
Vladimir Radosavljevic
2017-03-15 16:46:26 -07:00
committed by Cary Coutant
parent 152c92b261
commit 4d78db49e6
2 changed files with 69 additions and 40 deletions

View File

@ -1,3 +1,15 @@
2017-03-15 Vladimir Radosavljevic <Vladimir.Radosavljevic@imgtec.com>
* mips.cc (Mips_relobj::merge_processor_specific_data_): New data
member.
(Mips_relobj::merge_processor_specific_data): New method.
(Mips_relobj::do_read_symbols): Set merge_processor_specific_data_
to false, only if the input file is a binary or if object has no
contents except the section name string table and an empty symbol
table with the undefined symbol.
(Target_mips::do_finalize_sections): Refactor. Skip empty object files
for merging processor-specific data.
2017-03-15 Vladimir Radosavljevic <Vladimir.Radosavljevic@imgtec.com>
* mips.cc (Target_mips::Relocate::calculated_value_): New data

View File

@ -1592,10 +1592,11 @@ class Mips_relobj : public Sized_relobj_file<size, big_endian>
local_symbol_is_micromips_(), mips16_stub_sections_(),
local_non_16bit_calls_(), local_16bit_calls_(), local_mips16_fn_stubs_(),
local_mips16_call_stubs_(), gp_(0), has_reginfo_section_(false),
got_info_(NULL), section_is_mips16_fn_stub_(),
section_is_mips16_call_stub_(), section_is_mips16_call_fp_stub_(),
pdr_shndx_(-1U), attributes_section_data_(NULL), abiflags_(NULL),
gprmask_(0), cprmask1_(0), cprmask2_(0), cprmask3_(0), cprmask4_(0)
merge_processor_specific_data_(true), got_info_(NULL),
section_is_mips16_fn_stub_(), section_is_mips16_call_stub_(),
section_is_mips16_call_fp_stub_(), pdr_shndx_(-1U),
attributes_section_data_(NULL), abiflags_(NULL), gprmask_(0),
cprmask1_(0), cprmask2_(0), cprmask3_(0), cprmask4_(0)
{
this->is_pic_ = (ehdr.get_e_flags() & elfcpp::EF_MIPS_PIC) != 0;
this->is_n32_ = elfcpp::abi_n32(ehdr.get_e_flags());
@ -1836,6 +1837,11 @@ class Mips_relobj : public Sized_relobj_file<size, big_endian>
has_reginfo_section() const
{ return this->has_reginfo_section_; }
// Return whether we want to merge processor-specific data.
bool
merge_processor_specific_data() const
{ return this->merge_processor_specific_data_; }
// Return gprmask from the .reginfo section of this object.
Valtype
gprmask() const
@ -1926,6 +1932,8 @@ class Mips_relobj : public Sized_relobj_file<size, big_endian>
bool is_n32_ : 1;
// Whether the object contains a .reginfo section.
bool has_reginfo_section_ : 1;
// Whether we merge processor-specific data of this object to output.
bool merge_processor_specific_data_ : 1;
// The Mips_got_info for this object.
Mips_got_info<size, big_endian>* got_info_;
@ -6818,6 +6826,16 @@ Mips_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
// Call parent class to read symbol information.
this->base_read_symbols(sd);
// If this input file is a binary file, it has no processor
// specific data.
Input_file::Format format = this->input_file()->format();
if (format != Input_file::FORMAT_ELF)
{
gold_assert(format == Input_file::FORMAT_BINARY);
this->merge_processor_specific_data_ = false;
return;
}
// Read processor-specific flags in ELF file header.
const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
elfcpp::Elf_sizes<size>::ehdr_size,
@ -6837,10 +6855,27 @@ Mips_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
const size_t shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
const unsigned char* pshdrs = sd->section_headers->data();
const unsigned char* ps = pshdrs + shdr_size;
bool must_merge_processor_specific_data = false;
for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
{
elfcpp::Shdr<size, big_endian> shdr(ps);
// Sometimes an object has no contents except the section name string
// table and an empty symbol table with the undefined symbol. We
// don't want to merge processor-specific data from such an object.
if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
{
// Symbol table is not empty.
const typename elfcpp::Elf_types<size>::Elf_WXword sym_size =
elfcpp::Elf_sizes<size>::sym_size;
if (shdr.get_sh_size() > sym_size)
must_merge_processor_specific_data = true;
}
else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
// If this is neither an empty symbol table nor a string table,
// be conservative.
must_merge_processor_specific_data = true;
if (shdr.get_sh_type() == elfcpp::SHT_MIPS_REGINFO)
{
this->has_reginfo_section_ = true;
@ -7013,6 +7048,10 @@ Mips_relobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd)
this->pdr_shndx_ = i;
}
}
// This is rare.
if (!must_merge_processor_specific_data)
this->merge_processor_specific_data_ = false;
}
// Discard MIPS16 stub secions that are not needed.
@ -9600,6 +9639,8 @@ Target_mips<size, big_endian>::do_finalize_sections(Layout* layout,
const Input_objects* input_objects,
Symbol_table* symtab)
{
const bool relocatable = parameters->options().relocatable();
// Add +1 to MIPS16 and microMIPS init_ and _fini symbols so that DT_INIT and
// DT_FINI have correct values.
Mips_symbol<size>* init = static_cast<Mips_symbol<size>*>(
@ -9633,19 +9674,6 @@ Target_mips<size, big_endian>::do_finalize_sections(Layout* layout,
if (this->got16_addends_.size() > 0)
gold_error("Can't find matching LO16 reloc");
// Check for any mips16 stub sections that we can discard.
if (!parameters->options().relocatable())
{
for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
p != input_objects->relobj_end();
++p)
{
Mips_relobj<size, big_endian>* object =
Mips_relobj<size, big_endian>::as_mips_relobj(*p);
object->discard_mips16_stub_sections(symtab);
}
}
Valtype gprmask = 0;
Valtype cprmask1 = 0;
Valtype cprmask2 = 0;
@ -9660,6 +9688,13 @@ Target_mips<size, big_endian>::do_finalize_sections(Layout* layout,
Mips_relobj<size, big_endian>* relobj =
Mips_relobj<size, big_endian>::as_mips_relobj(*p);
// Check for any mips16 stub sections that we can discard.
if (!relocatable)
relobj->discard_mips16_stub_sections(symtab);
if (!relobj->merge_processor_specific_data())
continue;
// Merge .reginfo contents of input objects.
if (relobj->has_reginfo_section())
{
@ -9671,24 +9706,6 @@ Target_mips<size, big_endian>::do_finalize_sections(Layout* layout,
cprmask4 |= relobj->cprmask4();
}
Input_file::Format format = relobj->input_file()->format();
if (format != Input_file::FORMAT_ELF)
continue;
// If all input sections will be discarded, don't use this object
// file for merging processor specific flags.
bool should_merge_processor_specific_flags = false;
for (unsigned int i = 1; i < relobj->shnum(); ++i)
if (relobj->output_section(i) != NULL)
{
should_merge_processor_specific_flags = true;
break;
}
if (!should_merge_processor_specific_flags)
continue;
// Merge processor specific flags.
Mips_abiflags<big_endian> in_abiflags;
@ -9723,7 +9740,7 @@ Target_mips<size, big_endian>::do_finalize_sections(Layout* layout,
elfcpp::SHF_ALLOC,
abiflags_section, ORDER_INVALID, false);
if (!parameters->options().relocatable() && os != NULL)
if (!relocatable && os != NULL)
{
Output_segment* abiflags_segment =
layout->make_output_segment(elfcpp::PT_MIPS_ABIFLAGS, elfcpp::PF_R);
@ -9744,7 +9761,7 @@ Target_mips<size, big_endian>::do_finalize_sections(Layout* layout,
elfcpp::SHF_ALLOC, reginfo_section,
ORDER_INVALID, false);
if (!parameters->options().relocatable() && os != NULL)
if (!relocatable && os != NULL)
{
Output_segment* reginfo_segment =
layout->make_output_segment(elfcpp::PT_MIPS_REGINFO,
@ -9789,7 +9806,7 @@ Target_mips<size, big_endian>::do_finalize_sections(Layout* layout,
false, false);
}
if (!parameters->options().relocatable() && !parameters->doing_static_link())
if (!relocatable && !parameters->doing_static_link())
// In case there is no .got section, create one.
this->got_section(symtab, layout);
@ -9821,7 +9838,7 @@ Target_mips<size, big_endian>::do_finalize_sections(Layout* layout,
symtab));
// Add NULL segment.
if (!parameters->options().relocatable())
if (!relocatable)
layout->make_output_segment(elfcpp::PT_NULL, 0);
// Fill in some more dynamic tags.
@ -9833,7 +9850,7 @@ Target_mips<size, big_endian>::do_finalize_sections(Layout* layout,
Output_data_dynamic* const odyn = layout->dynamic_data();
if (odyn != NULL
&& !parameters->options().relocatable()
&& !relocatable
&& !parameters->doing_static_link())
{
unsigned int d_val;