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authorIan Lance Taylor <iant@google.com>2008-02-04 05:43:05 +0000
committerIan Lance Taylor <iant@google.com>2008-02-04 05:43:05 +0000
commita445fddf828b0e8251fbdce91bc9372e7efd24f0 (patch)
tree6af0ee8254a9432643798126eef663603d92eb08 /gold/output.cc
parentd16c732117ed4b752abd51dd1598c9cec9d2b26c (diff)
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Fully implement the SECTIONS clause.
Diffstat (limited to 'gold/output.cc')
-rw-r--r--gold/output.cc269
1 files changed, 226 insertions, 43 deletions
diff --git a/gold/output.cc b/gold/output.cc
index 1060de6..c0db1af 100644
--- a/gold/output.cc
+++ b/gold/output.cc
@@ -275,6 +275,7 @@ Output_segment_headers::do_sized_write(Output_file* of)
{
const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
+ gold_assert(all_phdrs_size == this->data_size());
unsigned char* view = of->get_output_view(this->offset(),
all_phdrs_size);
unsigned char* v = view;
@@ -287,6 +288,8 @@ Output_segment_headers::do_sized_write(Output_file* of)
v += phdr_size;
}
+ gold_assert(v - view == all_phdrs_size);
+
of->write_output_view(this->offset(), all_phdrs_size, view);
}
@@ -1371,6 +1374,15 @@ Output_section::Input_section::set_address_and_file_offset(
this->u2_.posd->set_address_and_file_offset(address, file_offset);
}
+// Reset the address and file offset.
+
+void
+Output_section::Input_section::reset_address_and_file_offset()
+{
+ if (!this->is_input_section())
+ this->u2_.posd->reset_address_and_file_offset();
+}
+
// Finalize the data size.
void
@@ -1444,6 +1456,7 @@ Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
: name_(name),
addralign_(0),
entsize_(0),
+ load_address_(0),
link_section_(NULL),
link_(0),
info_section_(NULL),
@@ -1463,6 +1476,8 @@ Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
should_link_to_dynsym_(false),
after_input_sections_(false),
requires_postprocessing_(false),
+ found_in_sections_clause_(false),
+ has_load_address_(false),
tls_offset_(0)
{
// An unallocated section has no address. Forcing this means that
@@ -1495,7 +1510,9 @@ Output_section::set_entsize(uint64_t v)
// receive special handling. In the normal case we don't always keep
// track of input sections for an Output_section. Instead, each
// Object keeps track of the Output_section for each of its input
-// sections.
+// sections. However, if HAVE_SECTIONS_SCRIPT is true, we do keep
+// track of input sections here; this is used when SECTIONS appears in
+// a linker script.
template<int size, bool big_endian>
off_t
@@ -1503,7 +1520,8 @@ Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
unsigned int shndx,
const char* secname,
const elfcpp::Shdr<size, big_endian>& shdr,
- unsigned int reloc_shndx)
+ unsigned int reloc_shndx,
+ bool have_sections_script)
{
elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
if ((addralign & (addralign - 1)) != 0)
@@ -1517,6 +1535,11 @@ Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
this->addralign_ = addralign;
typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
+ this->flags_ |= (sh_flags
+ & (elfcpp::SHF_WRITE
+ | elfcpp::SHF_ALLOC
+ | elfcpp::SHF_EXECINSTR));
+
uint64_t entsize = shdr.get_sh_entsize();
// .debug_str is a mergeable string section, but is not always so
@@ -1547,6 +1570,7 @@ Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
addralign);
if (aligned_offset_in_section > offset_in_section
+ && !have_sections_script
&& (sh_flags & elfcpp::SHF_EXECINSTR) != 0
&& object->target()->has_code_fill())
{
@@ -1572,7 +1596,7 @@ Output_section::add_input_section(Sized_relobj<size, big_endian>* object,
// We need to keep track of this section if we are already keeping
// track of sections, or if we are relaxing. FIXME: Add test for
// relaxing.
- if (!this->input_sections_.empty())
+ if (have_sections_script || !this->input_sections_.empty())
this->input_sections_.push_back(Input_section(object, shndx,
shdr.get_sh_size(),
addralign));
@@ -1587,6 +1611,15 @@ Output_section::add_output_section_data(Output_section_data* posd)
{
Input_section inp(posd);
this->add_output_section_data(&inp);
+
+ if (posd->is_data_size_valid())
+ {
+ off_t offset_in_section = this->current_data_size_for_child();
+ off_t aligned_offset_in_section = align_address(offset_in_section,
+ posd->addralign());
+ this->set_current_data_size_for_child(aligned_offset_in_section
+ + posd->data_size());
+ }
}
// Add arbitrary data to an output section by Input_section.
@@ -1809,6 +1842,17 @@ Output_section::set_final_data_size()
this->set_data_size(off - startoff);
}
+// Reset the address and file offset.
+
+void
+Output_section::do_reset_address_and_file_offset()
+{
+ for (Input_section_list::iterator p = this->input_sections_.begin();
+ p != this->input_sections_.end();
+ ++p)
+ p->reset_address_and_file_offset();
+}
+
// Set the TLS offset. Called only for SHT_TLS sections.
void
@@ -1863,7 +1907,7 @@ Output_section::do_write(Output_file* of)
{
std::string fill_data(parameters->target()->code_fill(p->length()));
of->write(output_section_file_offset + p->section_offset(),
- fill_data.data(), fill_data.size());
+ fill_data.data(), fill_data.size());
}
for (Input_section_list::iterator p = this->input_sections_.begin();
@@ -1917,7 +1961,8 @@ Output_section::write_to_postprocessing_buffer()
++p)
{
std::string fill_data(target->code_fill(p->length()));
- memcpy(buffer + p->section_offset(), fill_data.data(), fill_data.size());
+ memcpy(buffer + p->section_offset(), fill_data.data(),
+ fill_data.size());
}
off_t off = this->first_input_offset_;
@@ -1931,6 +1976,89 @@ Output_section::write_to_postprocessing_buffer()
}
}
+// Get the input sections for linker script processing. We leave
+// behind the Output_section_data entries. Note that this may be
+// slightly incorrect for merge sections. We will leave them behind,
+// but it is possible that the script says that they should follow
+// some other input sections, as in:
+// .rodata { *(.rodata) *(.rodata.cst*) }
+// For that matter, we don't handle this correctly:
+// .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
+// With luck this will never matter.
+
+uint64_t
+Output_section::get_input_sections(
+ uint64_t address,
+ const std::string& fill,
+ std::list<std::pair<Relobj*, unsigned int> >* input_sections)
+{
+ uint64_t orig_address = address;
+
+ address = align_address(address, this->addralign());
+
+ Input_section_list remaining;
+ for (Input_section_list::iterator p = this->input_sections_.begin();
+ p != this->input_sections_.end();
+ ++p)
+ {
+ if (p->is_input_section())
+ input_sections->push_back(std::make_pair(p->relobj(), p->shndx()));
+ else
+ {
+ uint64_t aligned_address = align_address(address, p->addralign());
+ if (aligned_address != address && !fill.empty())
+ {
+ section_size_type length =
+ convert_to_section_size_type(aligned_address - address);
+ std::string this_fill;
+ this_fill.reserve(length);
+ while (this_fill.length() + fill.length() <= length)
+ this_fill += fill;
+ if (this_fill.length() < length)
+ this_fill.append(fill, 0, length - this_fill.length());
+
+ Output_section_data* posd = new Output_data_const(this_fill, 0);
+ remaining.push_back(Input_section(posd));
+ }
+ address = aligned_address;
+
+ remaining.push_back(*p);
+
+ p->finalize_data_size();
+ address += p->data_size();
+ }
+ }
+
+ this->input_sections_.swap(remaining);
+ this->first_input_offset_ = 0;
+
+ uint64_t data_size = address - orig_address;
+ this->set_current_data_size_for_child(data_size);
+ return data_size;
+}
+
+// Add an input section from a script.
+
+void
+Output_section::add_input_section_for_script(Relobj* object,
+ unsigned int shndx,
+ off_t data_size,
+ uint64_t addralign)
+{
+ if (addralign > this->addralign_)
+ this->addralign_ = addralign;
+
+ off_t offset_in_section = this->current_data_size_for_child();
+ off_t aligned_offset_in_section = align_address(offset_in_section,
+ addralign);
+
+ this->set_current_data_size_for_child(aligned_offset_in_section
+ + data_size);
+
+ this->input_sections_.push_back(Input_section(object, shndx,
+ data_size, addralign));
+}
+
// Print stats for merge sections to stderr.
void
@@ -1951,12 +2079,14 @@ Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
vaddr_(0),
paddr_(0),
memsz_(0),
- align_(0),
+ max_align_(0),
+ min_p_align_(0),
offset_(0),
filesz_(0),
type_(type),
flags_(flags),
- is_align_known_(false)
+ is_max_align_known_(false),
+ are_addresses_set_(false)
{
}
@@ -1968,7 +2098,7 @@ Output_segment::add_output_section(Output_section* os,
bool front)
{
gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
- gold_assert(!this->is_align_known_);
+ gold_assert(!this->is_max_align_known_);
// Update the segment flags.
this->flags_ |= seg_flags;
@@ -2069,38 +2199,37 @@ Output_segment::add_output_section(Output_section* os,
void
Output_segment::add_initial_output_data(Output_data* od)
{
- gold_assert(!this->is_align_known_);
+ gold_assert(!this->is_max_align_known_);
this->output_data_.push_front(od);
}
// Return the maximum alignment of the Output_data in Output_segment.
-// Once we compute this, we prohibit new sections from being added.
uint64_t
-Output_segment::addralign()
+Output_segment::maximum_alignment()
{
- if (!this->is_align_known_)
+ if (!this->is_max_align_known_)
{
uint64_t addralign;
- addralign = Output_segment::maximum_alignment(&this->output_data_);
- if (addralign > this->align_)
- this->align_ = addralign;
+ addralign = Output_segment::maximum_alignment_list(&this->output_data_);
+ if (addralign > this->max_align_)
+ this->max_align_ = addralign;
- addralign = Output_segment::maximum_alignment(&this->output_bss_);
- if (addralign > this->align_)
- this->align_ = addralign;
+ addralign = Output_segment::maximum_alignment_list(&this->output_bss_);
+ if (addralign > this->max_align_)
+ this->max_align_ = addralign;
- this->is_align_known_ = true;
+ this->is_max_align_known_ = true;
}
- return this->align_;
+ return this->max_align_;
}
// Return the maximum alignment of a list of Output_data.
uint64_t
-Output_segment::maximum_alignment(const Output_data_list* pdl)
+Output_segment::maximum_alignment_list(const Output_data_list* pdl)
{
uint64_t ret = 0;
for (Output_data_list::const_iterator p = pdl->begin();
@@ -2136,33 +2265,41 @@ Output_segment::dynamic_reloc_count_list(const Output_data_list* pdl) const
return count;
}
-// Set the section addresses for an Output_segment. ADDR is the
-// address and *POFF is the file offset. Set the section indexes
-// starting with *PSHNDX. Return the address of the immediately
-// following segment. Update *POFF and *PSHNDX.
+// Set the section addresses for an Output_segment. If RESET is true,
+// reset the addresses first. ADDR is the address and *POFF is the
+// file offset. Set the section indexes starting with *PSHNDX.
+// Return the address of the immediately following segment. Update
+// *POFF and *PSHNDX.
uint64_t
-Output_segment::set_section_addresses(uint64_t addr, off_t* poff,
+Output_segment::set_section_addresses(bool reset, uint64_t addr, off_t* poff,
unsigned int* pshndx)
{
gold_assert(this->type_ == elfcpp::PT_LOAD);
- this->vaddr_ = addr;
- this->paddr_ = addr;
+ if (!reset && this->are_addresses_set_)
+ {
+ gold_assert(this->paddr_ == addr);
+ addr = this->vaddr_;
+ }
+ else
+ {
+ this->vaddr_ = addr;
+ this->paddr_ = addr;
+ this->are_addresses_set_ = true;
+ }
off_t orig_off = *poff;
this->offset_ = orig_off;
- *poff = align_address(*poff, this->addralign());
-
- addr = this->set_section_list_addresses(&this->output_data_, addr, poff,
- pshndx);
+ addr = this->set_section_list_addresses(reset, &this->output_data_,
+ addr, poff, pshndx);
this->filesz_ = *poff - orig_off;
off_t off = *poff;
- uint64_t ret = this->set_section_list_addresses(&this->output_bss_, addr,
- poff, pshndx);
+ uint64_t ret = this->set_section_list_addresses(reset, &this->output_bss_,
+ addr, poff, pshndx);
this->memsz_ = *poff - orig_off;
// Ignore the file offset adjustments made by the BSS Output_data
@@ -2176,7 +2313,7 @@ Output_segment::set_section_addresses(uint64_t addr, off_t* poff,
// structures.
uint64_t
-Output_segment::set_section_list_addresses(Output_data_list* pdl,
+Output_segment::set_section_list_addresses(bool reset, Output_data_list* pdl,
uint64_t addr, off_t* poff,
unsigned int* pshndx)
{
@@ -2188,7 +2325,23 @@ Output_segment::set_section_list_addresses(Output_data_list* pdl,
++p)
{
off = align_address(off, (*p)->addralign());
- (*p)->set_address_and_file_offset(addr + (off - startoff), off);
+
+ if (reset)
+ (*p)->reset_address_and_file_offset();
+
+ // When using a linker script the section will most likely
+ // already have an address.
+ if (!(*p)->is_address_valid())
+ (*p)->set_address_and_file_offset(addr + (off - startoff), off);
+ else
+ {
+ // The script may have inserted a skip forward, but it
+ // better not have moved backward.
+ gold_assert((*p)->address() >= addr);
+ off = startoff + ((*p)->address() - addr);
+ (*p)->set_file_offset(off);
+ (*p)->finalize_data_size();
+ }
// Unless this is a PT_TLS segment, we want to ignore the size
// of a SHF_TLS/SHT_NOBITS section. Such a section does not
@@ -2217,12 +2370,15 @@ Output_segment::set_offset()
{
gold_assert(this->type_ != elfcpp::PT_LOAD);
+ gold_assert(!this->are_addresses_set_);
+
if (this->output_data_.empty() && this->output_bss_.empty())
{
this->vaddr_ = 0;
this->paddr_ = 0;
+ this->are_addresses_set_ = true;
this->memsz_ = 0;
- this->align_ = 0;
+ this->min_p_align_ = 0;
this->offset_ = 0;
this->filesz_ = 0;
return;
@@ -2234,7 +2390,10 @@ Output_segment::set_offset()
else
first = this->output_data_.front();
this->vaddr_ = first->address();
- this->paddr_ = this->vaddr_;
+ this->paddr_ = (first->has_load_address()
+ ? first->load_address()
+ : this->vaddr_);
+ this->are_addresses_set_ = true;
this->offset_ = first->offset();
if (this->output_data_.empty())
@@ -2275,6 +2434,26 @@ Output_segment::set_tls_offsets()
(*p)->set_tls_offset(this->vaddr_);
}
+// Return the address of the first section.
+
+uint64_t
+Output_segment::first_section_load_address() const
+{
+ for (Output_data_list::const_iterator p = this->output_data_.begin();
+ p != this->output_data_.end();
+ ++p)
+ if ((*p)->is_section())
+ return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
+
+ for (Output_data_list::const_iterator p = this->output_bss_.begin();
+ p != this->output_bss_.end();
+ ++p)
+ if ((*p)->is_section())
+ return (*p)->has_load_address() ? (*p)->load_address() : (*p)->address();
+
+ gold_unreachable();
+}
+
// Return the number of Output_sections in an Output_segment.
unsigned int
@@ -2313,7 +2492,7 @@ Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
ophdr->put_p_filesz(this->filesz_);
ophdr->put_p_memsz(this->memsz_);
ophdr->put_p_flags(this->flags_);
- ophdr->put_p_align(this->addralign());
+ ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
}
// Write the section headers into V.
@@ -2534,7 +2713,8 @@ Output_section::add_input_section<32, false>(
unsigned int shndx,
const char* secname,
const elfcpp::Shdr<32, false>& shdr,
- unsigned int reloc_shndx);
+ unsigned int reloc_shndx,
+ bool have_sections_script);
#endif
#ifdef HAVE_TARGET_32_BIG
@@ -2545,7 +2725,8 @@ Output_section::add_input_section<32, true>(
unsigned int shndx,
const char* secname,
const elfcpp::Shdr<32, true>& shdr,
- unsigned int reloc_shndx);
+ unsigned int reloc_shndx,
+ bool have_sections_script);
#endif
#ifdef HAVE_TARGET_64_LITTLE
@@ -2556,7 +2737,8 @@ Output_section::add_input_section<64, false>(
unsigned int shndx,
const char* secname,
const elfcpp::Shdr<64, false>& shdr,
- unsigned int reloc_shndx);
+ unsigned int reloc_shndx,
+ bool have_sections_script);
#endif
#ifdef HAVE_TARGET_64_BIG
@@ -2567,7 +2749,8 @@ Output_section::add_input_section<64, true>(
unsigned int shndx,
const char* secname,
const elfcpp::Shdr<64, true>& shdr,
- unsigned int reloc_shndx);
+ unsigned int reloc_shndx,
+ bool have_sections_script);
#endif
#ifdef HAVE_TARGET_32_LITTLE