* elf_file.h: (class Elf_strtab): New class.
gold/:
	* gold.cc: (queue_initial_tasks): Pass incremental_inputs to
	Incremental_checker.
	* incremental.cc: (INCREMENTAL_LINK_VERSION): Change type to
	unsigned int.
	(class Incremental_inputs_header): New class.
	(Incremental_inputs_header_writer): Edit comment.
	(Incremental_inputs_entry): New class.
	(Incremental_inputs_entry_writer): Edit comment.
	(Sized_incremental_binary::do_find_incremental_inputs_section):
	Add *strtab_shndx parameter, fill it.
	(Sized_incremental_binary::do_check_inputs): New method.
	(Incremental_checker::can_incrementally_link_output_file): Use
	Sized_incremental_binary::check_inputs.
	(Incremental_inputs::report_command_line): Save command line in
	command_line_.
	* incremental.h:
	(Incremental_binary::find_incremental_inputs_section): New
	method.
	(Incremental_binary::do_find_incremental_inputs_section): Add
	strtab_shndx parameter.
	(Incremental_binary::do_check_inputs): New pure virtual method.
	(Sized_incremental_binary::do_check_inputs): Declare.
	(Incremental_checker::Incremental_checker): Add incremental_inputs
	parameter, use it to initialize incremental_inputs_.
	(Incremental_checker::incremental_inputs_): New field.
	(Incremental_checker::command_line): New method.
	(Incremental_checker::inputs): New method.
	(Incremental_checker::command_line_): New field.
This commit is contained in:
Ian Lance Taylor 2009-10-09 22:38:07 +00:00
parent c549a6949c
commit c4aa1e2d74
6 changed files with 276 additions and 21 deletions

View File

@ -1,3 +1,7 @@
2009-10-09 Mikolaj Zalewski <mikolajz@google.com>
* elf_file.h: (class Elf_strtab): New class.
2009-10-09 Mikolaj Zalewski <mikolajz@google.com>
* elfcpp_file.h: Fix header guard. Include <cstdio>.

View File

@ -228,6 +228,33 @@ class Elf_file
int large_shndx_offset_;
};
// A small wrapper around SHT_STRTAB data mapped to memory. It checks that the
// index is not out of bounds and the string is NULL-terminated.
class Elf_strtab
{
public:
// Construct an Elf_strtab for a section with contents *P and size SIZE.
Elf_strtab(const unsigned char* p, size_t size);
// Return the file offset to the section headers.
bool
get_c_string(size_t offset, const char** cstring) const
{
if (offset >= this->usable_size_)
return false;
*cstring = this->base_ + offset;
return true;
}
private:
// Contents of the section mapped to memory.
const char* base_;
// One larger that the position of the last NULL character in the section.
// For valid SHT_STRTAB sections, this is the size of the section.
size_t usable_size_;
};
// Inline function definitions.
// Check for presence of the ELF magic number.
@ -642,6 +669,18 @@ Elf_file<size, big_endian, File>::section_addralign(unsigned int shndx)
return shdr.get_sh_addralign();
}
inline
Elf_strtab::Elf_strtab(const unsigned char* p, size_t size)
{
// Check if the section is NUL-terminated. If it isn't, we ignore
// the last part to make sure we don't return non-NUL-terminated
// strings.
while (size > 0 && p[size - 1] != 0)
size--;
this->base_ = reinterpret_cast<const char*>(p);
this->usable_size_ = size;
}
} // End namespace elfcpp.
#endif // !defined(ELFCPP_FILE_H)

View File

@ -1,3 +1,34 @@
2009-10-09 Mikolaj Zalewski <mikolajz@google.com>
* gold.cc: (queue_initial_tasks): Pass incremental_inputs to
Incremental_checker.
* incremental.cc: (INCREMENTAL_LINK_VERSION): Change type to
unsigned int.
(class Incremental_inputs_header): New class.
(Incremental_inputs_header_writer): Edit comment.
(Incremental_inputs_entry): New class.
(Incremental_inputs_entry_writer): Edit comment.
(Sized_incremental_binary::do_find_incremental_inputs_section):
Add *strtab_shndx parameter, fill it.
(Sized_incremental_binary::do_check_inputs): New method.
(Incremental_checker::can_incrementally_link_output_file): Use
Sized_incremental_binary::check_inputs.
(Incremental_inputs::report_command_line): Save command line in
command_line_.
* incremental.h:
(Incremental_binary::find_incremental_inputs_section): New
method.
(Incremental_binary::do_find_incremental_inputs_section): Add
strtab_shndx parameter.
(Incremental_binary::do_check_inputs): New pure virtual method.
(Sized_incremental_binary::do_check_inputs): Declare.
(Incremental_checker::Incremental_checker): Add incremental_inputs
parameter, use it to initialize incremental_inputs_.
(Incremental_checker::incremental_inputs_): New field.
(Incremental_checker::command_line): New method.
(Incremental_checker::inputs): New method.
(Incremental_checker::command_line_): New field.
2009-10-09 Mikolaj Zalewski <mikolajz@google.com>
* incremental.cc: Include <cstdarg> and "target-select.h".

View File

@ -180,7 +180,8 @@ queue_initial_tasks(const General_options& options,
if (cmdline.options().incremental())
{
Incremental_checker incremental_checker(
parameters->options().output_file_name());
parameters->options().output_file_name(),
layout->incremental_inputs());
if (incremental_checker.can_incrementally_link_output_file())
{
// TODO: remove when incremental linking implemented.

View File

@ -37,7 +37,7 @@ namespace gold {
// Version information. Will change frequently during the development, later
// we could think about backward (and forward?) compatibility.
const int INCREMENTAL_LINK_VERSION = 1;
const unsigned int INCREMENTAL_LINK_VERSION = 1;
namespace internal {
@ -84,7 +84,42 @@ struct Incremental_inputs_entry_data
// Accessors.
// See internal::Incremental_input_header for fields descriptions.
// Reader class for .gnu_incremental_inputs header. See
// internal::Incremental_input_header for fields descriptions.
template<int size, bool big_endian>
class Incremental_inputs_header
{
public:
Incremental_inputs_header(const unsigned char *p)
: p_(reinterpret_cast<const internal::Incremental_inputs_header_data*>(p))
{ }
static const int data_size = sizeof(internal::Incremental_inputs_header_data);
elfcpp::Elf_Word
get_version() const
{ return Convert<32, big_endian>::convert_host(this->p_->version); }
elfcpp::Elf_Word
get_input_file_count() const
{ return Convert<32, big_endian>::convert_host(this->p_->input_file_count); }
elfcpp::Elf_Word
get_command_line_offset() const
{ return Convert<32, big_endian>::convert_host(this->p_->command_line_offset); }
elfcpp::Elf_Word
get_reserved() const
{ return Convert<32, big_endian>::convert_host(this->p_->reserved); }
private:
const internal::Incremental_inputs_header_data* p_;
};
// Writer class for .gnu_incremental_inputs header. See
// internal::Incremental_input_header for fields descriptions.
template<int size, bool big_endian>
class Incremental_inputs_header_write
{
@ -115,7 +150,48 @@ class Incremental_inputs_header_write
internal::Incremental_inputs_header_data* p_;
};
// See internal::Incremental_input_entry for fields descriptions.
// Reader class for an .gnu_incremental_inputs entry. See
// internal::Incremental_input_entry for fields descriptions.
template<int size, bool big_endian>
class Incremental_inputs_entry
{
public:
Incremental_inputs_entry(const unsigned char *p)
: p_(reinterpret_cast<const internal::Incremental_inputs_entry_data*>(p))
{ }
static const int data_size = sizeof(internal::Incremental_inputs_entry_data);
elfcpp::Elf_Word
get_filename_offset(elfcpp::Elf_Word v)
{ return Convert<32, big_endian>::convert_host(this->p_->filename_offset); }
elfcpp::Elf_Word
get_data_offset(elfcpp::Elf_Word v)
{ return Convert<32, big_endian>::convert_host(this->p_->data_offset); }
elfcpp::Elf_Xword
get_timestamp_sec(elfcpp::Elf_Xword v)
{ return Convert<64, big_endian>::convert_host(this->p_->timestamp_sec); }
elfcpp::Elf_Word
get_timestamp_nsec(elfcpp::Elf_Word v)
{ return Convert<32, big_endian>::convert_host(this->p_->timestamp_nsec); }
elfcpp::Elf_Word
get_input_type(elfcpp::Elf_Word v)
{ return Convert<32, big_endian>::convert_host(this->p_->input_type); }
elfcpp::Elf_Word
get_reserved(elfcpp::Elf_Word v)
{ return Convert<32, big_endian>::convert_host(this->p_->reserved); }
private:
const internal::Incremental_inputs_entry_data* p_;
};
// Writer class for an .gnu_incremental_inputs entry. See
// internal::Incremental_input_entry for fields descriptions.
template<int size, bool big_endian>
class Incremental_inputs_entry_write
{
@ -196,16 +272,77 @@ Incremental_binary::error(const char* format, ...) const
template<int size, bool big_endian>
bool
Sized_incremental_binary<size, big_endian>::do_find_incremental_inputs_section(
Location* location)
Location* location,
unsigned int* strtab_shndx)
{
unsigned int shndx = this->elf_file_.find_section_by_type(
elfcpp::SHT_GNU_INCREMENTAL_INPUTS);
if (shndx == elfcpp::SHN_UNDEF) // Not found.
return false;
*strtab_shndx = this->elf_file_.section_link(shndx);
*location = this->elf_file_.section_contents(shndx);
return true;
}
template<int size, bool big_endian>
bool
Sized_incremental_binary<size, big_endian>::do_check_inputs(
Incremental_inputs* incremental_inputs)
{
const int entry_size =
Incremental_inputs_entry_write<size, big_endian>::data_size;
const int header_size =
Incremental_inputs_header_write<size, big_endian>::data_size;
unsigned int strtab_shndx;
Location location;
if (!do_find_incremental_inputs_section(&location, &strtab_shndx))
{
explain_no_incremental(_("no incremental data from previous build"));
return false;
}
if (location.data_size < header_size
|| strtab_shndx >= this->elf_file_.shnum()
|| this->elf_file_.section_type(strtab_shndx) != elfcpp::SHT_STRTAB)
{
explain_no_incremental(_("invalid incremental build data"));
return false;
}
Location strtab_location(this->elf_file_.section_contents(strtab_shndx));
View data_view(view(location));
View strtab_view(view(strtab_location));
elfcpp::Elf_strtab strtab(strtab_view.data(), strtab_location.data_size);
Incremental_inputs_header<size, big_endian> header(data_view.data());
if (header.get_version() != INCREMENTAL_LINK_VERSION)
{
explain_no_incremental(_("different version of incremental build data"));
return false;
}
const char* command_line;
// We divide instead of multiplying to make sure there is no integer
// overflow.
size_t max_input_entries = (location.data_size - header_size) / entry_size;
if (header.get_input_file_count() > max_input_entries
|| !strtab.get_c_string(header.get_command_line_offset(), &command_line))
{
explain_no_incremental(_("invalid incremental build data"));
return false;
}
if (incremental_inputs->command_line() != command_line)
{
explain_no_incremental(_("command line changed"));
return false;
}
// TODO: compare incremental_inputs->inputs() with entries in data_view.
return true;
}
namespace
{
@ -322,14 +459,7 @@ Incremental_checker::can_incrementally_link_output_file()
Incremental_binary* binary = open_incremental_binary(&output);
if (binary == NULL)
return false;
Incremental_binary::Location inputs_location;
if (!binary->find_incremental_inputs_section(&inputs_location))
{
explain_no_incremental("no incremental data from previous build");
delete binary;
return false;
}
return true;
return binary->check_inputs(this->incremental_inputs_);
}
// Add the command line to the string table, setting
@ -366,7 +496,10 @@ Incremental_inputs::report_command_line(int argc, const char* const* argv)
}
args.append("'");
}
this->strtab_->add(args.c_str(), true, &this->command_line_key_);
this->command_line_ = args;
this->strtab_->add(this->command_line_.c_str(), false,
&this->command_line_key_);
}
// Record that the input argument INPUT is an achive ARCHIVE. This is

View File

@ -119,18 +119,34 @@ class Incremental_binary
void
error(const char* format, ...) const ATTRIBUTE_PRINTF_2;
// Find the .gnu_incremental_inputs section. It selects the first section
// of type SHT_GNU_INCREMENTAL_INPUTS. Returns false if such a section
// is not found.
bool
find_incremental_inputs_section(Location* location)
{ return do_find_incremental_inputs_section(location); }
find_incremental_inputs_section(Location* location,
unsigned int* strtab_shndx)
{ return do_find_incremental_inputs_section(location, strtab_shndx); }
// Check the .gnu_incremental_inputs section to see whether an incremental
// build is possible.
// TODO: on success, should report what files needs to be rebuilt.
// INCREMENTAL_INPUTS is used to read the canonical form of the command line
// and read the input arguments. TODO: for items that don't need to be
// rebuilt, we should also copy the incremental input information.
virtual bool
check_inputs(Incremental_inputs* incremental_inputs)
{ return do_check_inputs(incremental_inputs); }
protected:
// Find incremental inputs section.
virtual bool
do_find_incremental_inputs_section(Location* location) = 0;
do_find_incremental_inputs_section(Location* location,
unsigned int* strtab_shndx) = 0;
// Check the .gnu_incremental_inputs section to see whether an incremental
// build is possible.
virtual bool
do_check_inputs(Incremental_inputs* incremental_inputs) = 0;
private:
// Edited output file object.
@ -151,7 +167,11 @@ class Sized_incremental_binary : public Incremental_binary
protected:
virtual bool
do_find_incremental_inputs_section(Location* location);
do_find_incremental_inputs_section(Location* location,
unsigned int* strtab_shndx);
virtual bool
do_check_inputs(Incremental_inputs* incremental_inputs);
private:
// Output as an ELF file.
@ -168,8 +188,14 @@ open_incremental_binary(Output_file* file);
class Incremental_checker
{
public:
Incremental_checker(const char* output_name)
: output_name_(output_name)
// Check if the file named OUTPUT_NAME can be linked incrementally.
// INCREMENTAL_INPUTS must have the canonical form of the command line
// and input arguments filled - at this point of linking other fields are
// probably not filled yet. TODO: for inputs that don't need to be
// rebuilt, this function should fill the incremental input information.
Incremental_checker(const char* output_name,
Incremental_inputs* incremental_inputs)
: output_name_(output_name), incremental_inputs_(incremental_inputs)
{ }
// Analyzes the output file to check if incremental linking is possible and
@ -178,7 +204,12 @@ class Incremental_checker
can_incrementally_link_output_file();
private:
// Name of the output file to analyze.
const char* output_name_;
// The Incremental_inputs object. At this stage of link, only the command
// line and inputs are filled.
Incremental_inputs* incremental_inputs_;
};
// This class contains the information needed during an incremental
@ -227,6 +258,17 @@ class Incremental_inputs
get_stringpool()
{ return this->strtab_; }
// Return the canonical form of the command line, as will be stored in
// .gnu_incremental_strtab.
const std::string&
command_line()
{ return this->command_line_; }
// Return the input files found in the command line.
const Input_arguments*
inputs()
{ return this->inputs_; }
private:
// Code for each of the four possible variants of create_inputs_section_data.
template<int size, bool big_endian>
@ -289,8 +331,13 @@ class Incremental_inputs
// A map containing additional information about the input elements.
Inputs_info_map inputs_map_;
// Canonical form of the command line, as will be stored in
// .gnu_incremental_strtab.
std::string command_line_;
// The key of the command line string in the string pool.
Stringpool::Key command_line_key_;
// The .gnu_incremental_strtab string pool associated with the
// .gnu_incremental_inputs.
Stringpool* strtab_;