1 // inremental.h -- incremental linking support for gold -*- C++ -*-
3 // Copyright 2009 Free Software Foundation, Inc.
4 // Written by Mikolaj Zalewski <mikolajz@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
23 #ifndef GOLD_INCREMENTAL_H
24 #define GOLD_INCREMENTAL_H
29 #include "elfcpp_file.h"
30 #include "stringpool.h"
31 #include "workqueue.h"
40 class Incremental_inputs_checker
;
42 class Output_section_data
;
44 // Incremental input type as stored in .gnu_incremental_inputs.
46 enum Incremental_input_type
48 INCREMENTAL_INPUT_INVALID
= 0,
49 INCREMENTAL_INPUT_OBJECT
= 1,
50 INCREMENTAL_INPUT_ARCHIVE
= 2,
51 INCREMENTAL_INPUT_SHARED_LIBRARY
= 3,
52 INCREMENTAL_INPUT_SCRIPT
= 4
55 // Header of the .gnu_incremental_input section.
56 struct Incremental_inputs_header_data
58 // Incremental linker version.
59 elfcpp::Elf_Word version
;
61 // Numer of input files in the link.
62 elfcpp::Elf_Word input_file_count
;
64 // Offset of command line options in .gnu_incremental_strtab.
65 elfcpp::Elf_Word command_line_offset
;
68 elfcpp::Elf_Word reserved
;
71 // Data stored in .gnu_incremental_input after the header for each of the
72 // Incremental_input_header_data::input_file_count input entries.
73 struct Incremental_inputs_entry_data
75 // Offset of file name in .gnu_incremental_strtab section.
76 elfcpp::Elf_Word filename_offset
;
78 // Offset of data in .gnu_incremental_input.
79 elfcpp::Elf_Word data_offset
;
81 // Timestamp (in seconds).
82 elfcpp::Elf_Xword timestamp_sec
;
84 // Nano-second part of timestamp (if supported).
85 elfcpp::Elf_Word timestamp_nsec
;
87 // Type of the input entry.
88 elfcpp::Elf_Half input_type
;
91 elfcpp::Elf_Half reserved
;
94 // An object representing the ELF file we edit during an incremental build.
95 // Similar to Object or Dynobj, but operates on Output_file and contains
96 // method specific to file edition (TBD). This is the abstract parent class
97 // implemented in Sized_incremental_binary<size, big_endian> for a specific
98 // endianness and size.
100 class Incremental_binary
103 Incremental_binary(Output_file
* output
, Target
* target
)
104 : output_(output
), target_(target
)
108 ~Incremental_binary()
111 // Functions and types for the elfcpp::Elf_file interface. This
112 // permit us to use Incremental_binary as the File template parameter for
115 // The View class is returned by view. It must support a single
116 // method, data(). This is trivial, because Output_file::get_output_view
117 // does what we need.
121 View(const unsigned char* p
)
130 const unsigned char* p_
;
135 view(off_t file_offset
, section_size_type data_size
)
136 { return View(this->output_
->get_input_view(file_offset
, data_size
)); }
138 // A location in the file.
144 Location(off_t fo
, section_size_type ds
)
145 : file_offset(fo
), data_size(ds
)
149 : file_offset(0), data_size(0)
153 // Get a View given a Location.
154 View
view(Location loc
)
155 { return View(this->view(loc
.file_offset
, loc
.data_size
)); }
159 error(const char* format
, ...) const ATTRIBUTE_PRINTF_2
;
161 // Find the .gnu_incremental_inputs section. It selects the first section
162 // of type SHT_GNU_INCREMENTAL_INPUTS. Returns false if such a section
165 find_incremental_inputs_section(Location
* location
,
166 unsigned int* strtab_shndx
)
167 { return do_find_incremental_inputs_section(location
, strtab_shndx
); }
169 // Check the .gnu_incremental_inputs section to see whether an incremental
170 // build is possible.
171 // TODO: on success, should report what files needs to be rebuilt.
172 // INCREMENTAL_INPUTS is used to read the canonical form of the command line
173 // and read the input arguments. TODO: for items that don't need to be
174 // rebuilt, we should also copy the incremental input information.
176 check_inputs(Incremental_inputs
* incremental_inputs
)
177 { return do_check_inputs(incremental_inputs
); }
180 // Find incremental inputs section.
182 do_find_incremental_inputs_section(Location
* location
,
183 unsigned int* strtab_shndx
) = 0;
185 // Check the .gnu_incremental_inputs section to see whether an incremental
186 // build is possible.
188 do_check_inputs(Incremental_inputs
* incremental_inputs
) = 0;
191 // Edited output file object.
192 Output_file
* output_
;
193 // Target of the output file.
197 template<int size
, bool big_endian
>
198 class Sized_incremental_binary
: public Incremental_binary
201 Sized_incremental_binary(Output_file
* output
,
202 const elfcpp::Ehdr
<size
, big_endian
>& ehdr
,
204 : Incremental_binary(output
, target
), elf_file_(this, ehdr
)
209 do_find_incremental_inputs_section(Location
* location
,
210 unsigned int* strtab_shndx
);
213 do_check_inputs(Incremental_inputs
* incremental_inputs
);
216 // Output as an ELF file.
217 elfcpp::Elf_file
<size
, big_endian
, Incremental_binary
> elf_file_
;
220 // Create an Incremental_binary object for FILE. Returns NULL is this is not
221 // possible, e.g. FILE is not an ELF file or has an unsupported target.
223 open_incremental_binary(Output_file
* file
);
225 // Code invoked early during an incremental link that checks what files need
227 class Incremental_checker
230 // Check if the file named OUTPUT_NAME can be linked incrementally.
231 // INCREMENTAL_INPUTS must have the canonical form of the command line
232 // and input arguments filled - at this point of linking other fields are
233 // probably not filled yet. TODO: for inputs that don't need to be
234 // rebuilt, this function should fill the incremental input information.
235 Incremental_checker(const char* output_name
,
236 Incremental_inputs
* incremental_inputs
)
237 : output_name_(output_name
), incremental_inputs_(incremental_inputs
)
240 // Analyzes the output file to check if incremental linking is possible and
241 // what files needs to be relinked.
243 can_incrementally_link_output_file();
246 // Name of the output file to analyze.
247 const char* output_name_
;
249 // The Incremental_inputs object. At this stage of link, only the command
250 // line and inputs are filled.
251 Incremental_inputs
* incremental_inputs_
;
254 // This class contains the information needed during an incremental
255 // build about the inputs necessary to build the .gnu_incremental_inputs.
256 class Incremental_inputs
260 : lock_(new Lock()), inputs_(NULL
), command_line_key_(0),
261 strtab_(new Stringpool())
263 ~Incremental_inputs() { delete this->strtab_
; }
265 // Record the command line.
267 report_command_line(int argc
, const char* const* argv
);
269 // Record the input arguments obtained from parsing the command line.
271 report_inputs(const Input_arguments
& inputs
)
272 { this->inputs_
= &inputs
; }
274 // Record that the input argument INPUT is an archive ARCHIVE.
276 report_archive(const Input_argument
* input
, Archive
* archive
);
278 // Record that the input argument INPUT is to an object OBJ.
280 report_object(const Input_argument
* input
, Object
* obj
);
282 // Record that the input argument INPUT is to an script SCRIPT.
284 report_script(const Input_argument
* input
, Timespec mtime
,
285 Script_info
* script
);
287 // Prepare for layout. Called from Layout::finalize.
291 // Create the content of the .gnu_incremental_inputs section.
293 create_incremental_inputs_section_data();
295 // Return the .gnu_incremental_strtab stringpool.
298 { return this->strtab_
; }
300 // Return the canonical form of the command line, as will be stored in
301 // .gnu_incremental_strtab.
304 { return this->command_line_
; }
306 // Return the input files found in the command line.
307 const Input_arguments
*
309 { return this->inputs_
; }
312 // Code for each of the four possible variants of create_inputs_section_data.
313 template<int size
, bool big_endian
>
315 sized_create_inputs_section_data();
317 // Compute indexes in the order in which the inputs should appear in
318 // .gnu_incremental_inputs and put file names to the stringtable.
319 // This needs to be done after all the scripts are parsed.
322 finalize_inputs(Input_argument_list::const_iterator begin
,
323 Input_argument_list::const_iterator end
,
324 unsigned int* index
);
326 // Additional data about an input needed for an incremental link.
327 // None of these pointers is owned by the structure.
331 : type(INCREMENTAL_INPUT_INVALID
), archive(NULL
), filename_key(0),
335 // Type of the file pointed by this argument.
336 Incremental_input_type type
;
340 // Present if type == INCREMENTAL_INPUT_ARCHIVE.
343 // Present if type == INCREMENTAL_INPUT_OBJECT or
344 // INCREMENTAL_INPUT_SHARED_LIBRARY.
347 // Present if type == INCREMENTAL_INPUT_SCRIPT.
351 // Key of the filename string in the section stringtable.
352 Stringpool::Key filename_key
;
354 // Position of the entry information in the output section.
357 // Last modification time of the file.
361 typedef std::map
<const Input_argument
*, Input_info
> Inputs_info_map
;
363 // A lock guarding access to inputs_ during the first phase of linking, when
364 // report_ function may be called from multiple threads.
367 // The list of input arguments obtained from parsing the command line.
368 const Input_arguments
* inputs_
;
370 // A map containing additional information about the input elements.
371 Inputs_info_map inputs_map_
;
373 // Canonical form of the command line, as will be stored in
374 // .gnu_incremental_strtab.
375 std::string command_line_
;
377 // The key of the command line string in the string pool.
378 Stringpool::Key command_line_key_
;
380 // The .gnu_incremental_strtab string pool associated with the
381 // .gnu_incremental_inputs.
385 } // End namespace gold.
387 #endif // !defined(GOLD_INCREMENTAL_H)