Commit | Line | Data |
---|---|---|
dbe717ef ILT |
1 | // script.h -- handle linker scripts for gold -*- C++ -*- |
2 | ||
62dfdd4d | 3 | // Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. |
6cb15b7f ILT |
4 | // Written by Ian Lance Taylor <iant@google.com>. |
5 | ||
6 | // This file is part of gold. | |
7 | ||
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. | |
12 | ||
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. | |
17 | ||
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. | |
22 | ||
dbe717ef ILT |
23 | // We implement a subset of the original GNU ld linker script language |
24 | // for compatibility. The goal is not to implement the entire | |
25 | // language. It is merely to implement enough to handle common uses. | |
26 | // In particular we need to handle /usr/lib/libc.so on a typical | |
27 | // GNU/Linux system, and we want to handle linker scripts used by the | |
28 | // Linux kernel build. | |
29 | ||
30 | #ifndef GOLD_SCRIPT_H | |
31 | #define GOLD_SCRIPT_H | |
32 | ||
494e05f4 | 33 | #include <cstdio> |
04bf7072 | 34 | #include <string> |
e5756efb ILT |
35 | #include <vector> |
36 | ||
494e05f4 | 37 | #include "script-sections.h" |
09124467 | 38 | |
dbe717ef ILT |
39 | namespace gold |
40 | { | |
41 | ||
42 | class General_options; | |
3c2fafa5 | 43 | class Command_line; |
dbe717ef ILT |
44 | class Symbol_table; |
45 | class Layout; | |
7d9e3d98 | 46 | class Mapfile; |
3c2fafa5 | 47 | class Input_argument; |
072fe7ce | 48 | class Input_arguments; |
dbe717ef ILT |
49 | class Input_objects; |
50 | class Input_group; | |
51 | class Input_file; | |
a445fddf | 52 | class Output_segment; |
dbe717ef | 53 | class Task_token; |
3c2fafa5 | 54 | class Workqueue; |
494e05f4 ILT |
55 | struct Version_dependency_list; |
56 | struct Version_expression_list; | |
57 | struct Version_tree; | |
98e090bd ILT |
58 | struct Version_expression; |
59 | class Lazy_demangler; | |
dbe717ef | 60 | |
e5756efb ILT |
61 | // This class represents an expression in a linker script. |
62 | ||
63 | class Expression | |
64 | { | |
65 | protected: | |
66 | // These should only be created by child classes. | |
67 | Expression() | |
68 | { } | |
69 | ||
70 | public: | |
71 | virtual ~Expression() | |
72 | { } | |
73 | ||
a445fddf | 74 | // Return the value of the expression which is not permitted to |
919ed24c ILT |
75 | // refer to the dot symbol. CHECK_ASSERTIONS is true if we should |
76 | // check whether assertions are true. | |
e5756efb | 77 | uint64_t |
919ed24c | 78 | eval(const Symbol_table*, const Layout*, bool check_assertions); |
e5756efb | 79 | |
a445fddf | 80 | // Return the value of an expression which is permitted to refer to |
77e65537 ILT |
81 | // the dot symbol. DOT_VALUE is the absolute value of the dot |
82 | // symbol. DOT_SECTION is the section in which dot is defined; it | |
83 | // should be NULL if the dot symbol has an absolute value (e.g., is | |
84 | // defined in a SECTIONS clause outside of any output section | |
85 | // definition). This sets *RESULT_SECTION to indicate where the | |
86 | // value is defined. If the value is absolute *RESULT_SECTION will | |
87 | // be NULL. Note that the returned value is still an absolute | |
88 | // value; to get a section relative value the caller must subtract | |
89 | // the section address. | |
a445fddf | 90 | uint64_t |
919ed24c ILT |
91 | eval_with_dot(const Symbol_table*, const Layout*, bool check_assertions, |
92 | uint64_t dot_value, Output_section* dot_section, | |
93 | Output_section** result_section); | |
a445fddf ILT |
94 | |
95 | // Return the value of an expression which may or may not be | |
96 | // permitted to refer to the dot symbol, depending on | |
97 | // is_dot_available. | |
98 | uint64_t | |
919ed24c ILT |
99 | eval_maybe_dot(const Symbol_table*, const Layout*, bool check_assertions, |
100 | bool is_dot_available, uint64_t dot_value, | |
101 | Output_section* dot_section, | |
77e65537 | 102 | Output_section** result_section); |
a445fddf | 103 | |
494e05f4 ILT |
104 | // Print the expression to the FILE. This is for debugging. |
105 | virtual void | |
106 | print(FILE*) const = 0; | |
107 | ||
e5756efb ILT |
108 | protected: |
109 | struct Expression_eval_info; | |
110 | ||
111 | public: | |
112 | // Compute the value of the expression (implemented by child class). | |
113 | // This is public rather than protected because it is called | |
114 | // directly by children of Expression on other Expression objects. | |
115 | virtual uint64_t | |
116 | value(const Expression_eval_info*) = 0; | |
117 | ||
118 | private: | |
119 | // May not be copied. | |
120 | Expression(const Expression&); | |
121 | Expression& operator=(const Expression&); | |
122 | }; | |
123 | ||
09124467 ILT |
124 | |
125 | // Version_script_info stores information parsed from the version | |
126 | // script, either provided by --version-script or as part of a linker | |
127 | // script. A single Version_script_info object per target is owned by | |
128 | // Script_options. | |
129 | ||
494e05f4 ILT |
130 | class Version_script_info |
131 | { | |
09124467 | 132 | public: |
6affe781 ILT |
133 | // The languages which can be specified in a versionn script. |
134 | enum Language | |
135 | { | |
136 | LANGUAGE_C, // No demangling. | |
137 | LANGUAGE_CXX, // C++ demangling. | |
138 | LANGUAGE_JAVA, // Java demangling. | |
139 | LANGUAGE_COUNT | |
140 | }; | |
141 | ||
142 | Version_script_info(); | |
143 | ||
09124467 ILT |
144 | ~Version_script_info(); |
145 | ||
1ef1f3d3 ILT |
146 | // Clear everything. |
147 | void | |
148 | clear(); | |
149 | ||
6affe781 ILT |
150 | // Finalize the version control information. |
151 | void | |
152 | finalize(); | |
153 | ||
154 | // Return whether the information is finalized. | |
155 | bool | |
156 | is_finalized() const | |
157 | { return this->is_finalized_; } | |
158 | ||
09124467 ILT |
159 | // Return whether any version were defined in the version script. |
160 | bool | |
161 | empty() const | |
162 | { return this->version_trees_.empty(); } | |
163 | ||
057ead22 | 164 | // If there is a version associated with SYMBOL, return true, and |
98e090bd ILT |
165 | // set *VERSION to the version, and *IS_GLOBAL to whether the symbol |
166 | // should be global. Otherwise, return false. | |
057ead22 | 167 | bool |
98e090bd ILT |
168 | get_symbol_version(const char* symbol, std::string* version, |
169 | bool* is_global) const; | |
057ead22 ILT |
170 | |
171 | // Return whether this symbol matches the local: section of some | |
172 | // version. | |
09124467 ILT |
173 | bool |
174 | symbol_is_local(const char* symbol) const | |
98e090bd ILT |
175 | { |
176 | bool is_global; | |
177 | return (this->get_symbol_version(symbol, NULL, &is_global) | |
178 | && !is_global); | |
179 | } | |
09124467 ILT |
180 | |
181 | // Return the names of versions defined in the version script. | |
09124467 ILT |
182 | std::vector<std::string> |
183 | get_versions() const; | |
184 | ||
185 | // Return the list of dependencies for this version. | |
186 | std::vector<std::string> | |
187 | get_dependencies(const char* version) const; | |
188 | ||
189 | // The following functions should only be used by the bison helper | |
190 | // functions. They allocate new structs whose memory belongs to | |
191 | // Version_script_info. The bison functions copy the information | |
192 | // from the version script into these structs. | |
193 | struct Version_dependency_list* | |
194 | allocate_dependency_list(); | |
195 | ||
196 | struct Version_expression_list* | |
197 | allocate_expression_list(); | |
198 | ||
199 | struct Version_tree* | |
200 | allocate_version_tree(); | |
201 | ||
6affe781 ILT |
202 | // Build the lookup tables after all data have been read. |
203 | void | |
204 | build_lookup_tables(); | |
205 | ||
62dfdd4d ILT |
206 | // Give an error if there are any unmatched names in the version |
207 | // script. | |
208 | void | |
209 | check_unmatched_names(const Symbol_table*) const; | |
210 | ||
494e05f4 ILT |
211 | // Print contents to the FILE. This is for debugging. |
212 | void | |
213 | print(FILE*) const; | |
214 | ||
09124467 | 215 | private: |
494e05f4 ILT |
216 | void |
217 | print_expression_list(FILE* f, const Version_expression_list*) const; | |
218 | ||
6affe781 ILT |
219 | bool |
220 | get_symbol_version_helper(const char* symbol, | |
221 | bool check_global, | |
222 | std::string* pversion) const; | |
223 | ||
98e090bd ILT |
224 | // Fast lookup information for a given language. |
225 | ||
226 | // We map from exact match strings to Version_tree's. Historically | |
227 | // version scripts sometimes have the same symbol multiple times, | |
228 | // which is ambiguous. We warn about that case by storing the | |
229 | // second Version_tree we see. | |
230 | struct Version_tree_match | |
231 | { | |
232 | Version_tree_match(const Version_tree* r, bool ig, | |
233 | const Version_expression* e) | |
234 | : real(r), is_global(ig), expression(e), ambiguous(NULL) | |
235 | { } | |
236 | ||
237 | // The Version_tree that we return. | |
238 | const Version_tree* real; | |
239 | // True if this is a global match for the REAL member, false if it | |
240 | // is a local match. | |
241 | bool is_global; | |
242 | // Point back to the Version_expression for which we created this | |
243 | // match. | |
244 | const Version_expression* expression; | |
245 | // If not NULL, another Version_tree that defines the symbol. | |
246 | const Version_tree* ambiguous; | |
247 | }; | |
248 | ||
249 | // Map from an exact match string to a Version_tree. | |
250 | ||
251 | typedef Unordered_map<std::string, Version_tree_match> Exact; | |
62dfdd4d | 252 | |
6affe781 ILT |
253 | // Fast lookup information for a glob pattern. |
254 | struct Glob | |
255 | { | |
256 | Glob() | |
98e090bd | 257 | : expression(NULL), version(NULL), is_global(false) |
6affe781 ILT |
258 | { } |
259 | ||
98e090bd ILT |
260 | Glob(const Version_expression* e, const Version_tree* v, bool ig) |
261 | : expression(e), version(v), is_global(ig) | |
6affe781 ILT |
262 | { } |
263 | ||
98e090bd ILT |
264 | // A pointer to the version expression holding the pattern to |
265 | // match and the language to use for demangling the symbol before | |
266 | // doing the match. | |
267 | const Version_expression* expression; | |
6affe781 ILT |
268 | // The Version_tree we use if this pattern matches. |
269 | const Version_tree* version; | |
98e090bd ILT |
270 | // True if this is a global symbol. |
271 | bool is_global; | |
6affe781 ILT |
272 | }; |
273 | ||
98e090bd | 274 | typedef std::vector<Glob> Globs; |
6affe781 | 275 | |
98e090bd ILT |
276 | bool |
277 | unquote(std::string*) const; | |
6affe781 | 278 | |
98e090bd ILT |
279 | void |
280 | add_exact_match(const std::string&, const Version_tree*, bool is_global, | |
281 | const Version_expression*, Exact*); | |
09124467 | 282 | |
6affe781 ILT |
283 | void |
284 | build_expression_list_lookup(const Version_expression_list*, | |
98e090bd ILT |
285 | const Version_tree*, bool); |
286 | ||
287 | const char* | |
288 | get_name_to_match(const char*, int, | |
289 | Lazy_demangler*, Lazy_demangler*) const; | |
6affe781 ILT |
290 | |
291 | // All the version dependencies we allocate. | |
292 | std::vector<Version_dependency_list*> dependency_lists_; | |
293 | // All the version expressions we allocate. | |
294 | std::vector<Version_expression_list*> expression_lists_; | |
295 | // The list of versions. | |
296 | std::vector<Version_tree*> version_trees_; | |
98e090bd ILT |
297 | // Exact matches for global symbols, by language. |
298 | Exact* exact_[LANGUAGE_COUNT]; | |
299 | // A vector of glob patterns mapping to Version_trees. | |
300 | Globs globs_; | |
301 | // The default version to use, if there is one. This is from a | |
302 | // pattern of "*". | |
303 | const Version_tree* default_version_; | |
304 | // True if the default version is global. | |
305 | bool default_is_global_; | |
6affe781 ILT |
306 | // Whether this has been finalized. |
307 | bool is_finalized_; | |
09124467 ILT |
308 | }; |
309 | ||
494e05f4 ILT |
310 | // This class manages assignments to symbols. These can appear in |
311 | // three different locations in scripts: outside of a SECTIONS clause, | |
312 | // within a SECTIONS clause, and within an output section definition | |
313 | // within a SECTIONS clause. This can also appear on the command line | |
314 | // via the --defsym command line option. | |
315 | ||
316 | class Symbol_assignment | |
317 | { | |
318 | public: | |
99fff23b ILT |
319 | Symbol_assignment(const char* name, size_t namelen, bool is_defsym, |
320 | Expression* val, bool provide, bool hidden) | |
321 | : name_(name, namelen), val_(val), is_defsym_(is_defsym), | |
322 | provide_(provide), hidden_(hidden), sym_(NULL) | |
494e05f4 ILT |
323 | { } |
324 | ||
325 | // Add the symbol to the symbol table. | |
326 | void | |
9b07f471 | 327 | add_to_table(Symbol_table*); |
494e05f4 ILT |
328 | |
329 | // Finalize the symbol value. | |
a445fddf ILT |
330 | void |
331 | finalize(Symbol_table*, const Layout*); | |
332 | ||
333 | // Finalize the symbol value when it can refer to the dot symbol. | |
334 | void | |
77e65537 ILT |
335 | finalize_with_dot(Symbol_table*, const Layout*, uint64_t dot_value, |
336 | Output_section* dot_section); | |
a445fddf ILT |
337 | |
338 | // Set the symbol value, but only if the value is absolute. This is | |
77e65537 | 339 | // used while processing a SECTIONS clause. We assume that dot is |
919ed24c | 340 | // an absolute value here. We do not check assertions. |
a445fddf ILT |
341 | void |
342 | set_if_absolute(Symbol_table*, const Layout*, bool is_dot_available, | |
77e65537 | 343 | uint64_t dot_value); |
494e05f4 ILT |
344 | |
345 | // Print the assignment to the FILE. This is for debugging. | |
346 | void | |
347 | print(FILE*) const; | |
348 | ||
349 | private: | |
a445fddf ILT |
350 | // Shared by finalize and finalize_with_dot. |
351 | void | |
352 | finalize_maybe_dot(Symbol_table*, const Layout*, bool is_dot_available, | |
77e65537 | 353 | uint64_t dot_value, Output_section* dot_section); |
a445fddf | 354 | |
494e05f4 ILT |
355 | // Sized version of finalize. |
356 | template<int size> | |
357 | void | |
a445fddf | 358 | sized_finalize(Symbol_table*, const Layout*, bool is_dot_available, |
77e65537 | 359 | uint64_t dot_value, Output_section*); |
494e05f4 ILT |
360 | |
361 | // Symbol name. | |
362 | std::string name_; | |
363 | // Expression to assign to symbol. | |
364 | Expression* val_; | |
99fff23b ILT |
365 | // True if this symbol is defined by a --defsym, false if it is |
366 | // defined in a linker script. | |
367 | bool is_defsym_; | |
494e05f4 ILT |
368 | // Whether the assignment should be provided (only set if there is |
369 | // an undefined reference to the symbol. | |
370 | bool provide_; | |
371 | // Whether the assignment should be hidden. | |
372 | bool hidden_; | |
373 | // The entry in the symbol table. | |
374 | Symbol* sym_; | |
375 | }; | |
376 | ||
377 | // This class manages assertions in linker scripts. These can appear | |
378 | // in all the places where a Symbol_assignment can appear. | |
379 | ||
380 | class Script_assertion | |
381 | { | |
382 | public: | |
2ea97941 | 383 | Script_assertion(Expression* check, const char* message, |
494e05f4 | 384 | size_t messagelen) |
2ea97941 | 385 | : check_(check), message_(message, messagelen) |
494e05f4 ILT |
386 | { } |
387 | ||
388 | // Check the assertion. | |
389 | void | |
390 | check(const Symbol_table*, const Layout*); | |
391 | ||
392 | // Print the assertion to the FILE. This is for debugging. | |
393 | void | |
394 | print(FILE*) const; | |
395 | ||
396 | private: | |
397 | // The expression to check. | |
398 | Expression* check_; | |
399 | // The message to issue if the expression fails. | |
400 | std::string message_; | |
401 | }; | |
402 | ||
e5756efb ILT |
403 | // We can read a linker script in two different contexts: when |
404 | // initially parsing the command line, and when we find an input file | |
405 | // which is actually a linker script. Also some of the data which can | |
406 | // be set by a linker script can also be set via command line options | |
407 | // like -e and --defsym. This means that we have a type of data which | |
408 | // can be set both during command line option parsing and while | |
409 | // reading input files. We store that data in an instance of this | |
410 | // object. We will keep pointers to that instance in both the | |
411 | // Command_line and Layout objects. | |
412 | ||
413 | class Script_options | |
414 | { | |
415 | public: | |
416 | Script_options(); | |
417 | ||
494e05f4 | 418 | // Add a symbol to be defined. |
e5756efb | 419 | void |
99fff23b ILT |
420 | add_symbol_assignment(const char* name, size_t length, bool is_defsym, |
421 | Expression* value, bool provide, bool hidden); | |
494e05f4 ILT |
422 | |
423 | // Add an assertion. | |
424 | void | |
425 | add_assertion(Expression* check, const char* message, size_t messagelen); | |
e5756efb ILT |
426 | |
427 | // Define a symbol from the command line. | |
428 | bool | |
429 | define_symbol(const char* definition); | |
430 | ||
919ed24c ILT |
431 | // Create sections required by any linker scripts. |
432 | void | |
433 | create_script_sections(Layout*); | |
434 | ||
e5756efb ILT |
435 | // Add all symbol definitions to the symbol table. |
436 | void | |
9b07f471 | 437 | add_symbols_to_table(Symbol_table*); |
e5756efb | 438 | |
a445fddf | 439 | // Finalize the symbol values. Also check assertions. |
e5756efb ILT |
440 | void |
441 | finalize_symbols(Symbol_table*, const Layout*); | |
442 | ||
09124467 ILT |
443 | // Version information parsed from a version script. Everything |
444 | // else has a pointer to this object. | |
445 | Version_script_info* | |
446 | version_script_info() | |
494e05f4 | 447 | { return &this->version_script_info_; } |
09124467 | 448 | |
a5dc0706 ILT |
449 | const Version_script_info* |
450 | version_script_info() const | |
451 | { return &this->version_script_info_; } | |
452 | ||
494e05f4 ILT |
453 | // A SECTIONS clause parsed from a linker script. Everything else |
454 | // has a pointer to this object. | |
455 | Script_sections* | |
456 | script_sections() | |
457 | { return &this->script_sections_; } | |
e5756efb | 458 | |
8f2eb564 ILT |
459 | const Script_sections* |
460 | script_sections() const | |
461 | { return &this->script_sections_; } | |
462 | ||
a445fddf ILT |
463 | // Whether we saw a SECTIONS clause. |
464 | bool | |
465 | saw_sections_clause() const | |
466 | { return this->script_sections_.saw_sections_clause(); } | |
467 | ||
1c4f3631 ILT |
468 | // Whether we saw a PHDRS clause. |
469 | bool | |
470 | saw_phdrs_clause() const | |
471 | { return this->script_sections_.saw_phdrs_clause(); } | |
472 | ||
a445fddf ILT |
473 | // Set section addresses using a SECTIONS clause. Return the |
474 | // segment which should hold the file header and segment headers; | |
475 | // this may return NULL, in which case the headers are not in a | |
476 | // loadable segment. | |
477 | Output_segment* | |
478 | set_section_addresses(Symbol_table*, Layout*); | |
479 | ||
494e05f4 | 480 | // Print the script to the FILE. This is for debugging. |
e5756efb | 481 | void |
494e05f4 ILT |
482 | print(FILE*) const; |
483 | ||
484 | private: | |
485 | // We keep a list of symbol assignments which occur outside of a | |
486 | // SECTIONS clause. | |
487 | typedef std::vector<Symbol_assignment*> Symbol_assignments; | |
488 | ||
489 | // We keep a list of all assertions whcih occur outside of a | |
490 | // SECTIONS clause. | |
491 | typedef std::vector<Script_assertion*> Assertions; | |
e5756efb ILT |
492 | |
493 | // The entry address. This will be empty if not set. | |
494 | std::string entry_; | |
495 | // Symbols to set. | |
496 | Symbol_assignments symbol_assignments_; | |
494e05f4 ILT |
497 | // Assertions to check. |
498 | Assertions assertions_; | |
09124467 ILT |
499 | // Version information parsed from a version script. |
500 | Version_script_info version_script_info_; | |
494e05f4 ILT |
501 | // Information from any SECTIONS clauses. |
502 | Script_sections script_sections_; | |
e5756efb ILT |
503 | }; |
504 | ||
072fe7ce ILT |
505 | // Information about a script input that will persist during the whole linker |
506 | // run. Needed only during an incremental build to retrieve the input files | |
507 | // added by this script. | |
508 | ||
509 | class Script_info | |
510 | { | |
511 | public: | |
2ea97941 ILT |
512 | Script_info(Input_arguments* inputs) |
513 | : inputs_(inputs) | |
072fe7ce ILT |
514 | { } |
515 | ||
516 | // Returns the input files included because of this script. | |
517 | Input_arguments* | |
518 | inputs() | |
98fa85cb | 519 | { return this->inputs_; } |
072fe7ce ILT |
520 | |
521 | private: | |
522 | Input_arguments* inputs_; | |
523 | }; | |
524 | ||
dbe717ef | 525 | // FILE was found as an argument on the command line, but was not |
da769d56 ILT |
526 | // recognized as an ELF file. Try to read it as a script. Return |
527 | // true if the file was handled. This has to handle /usr/lib/libc.so | |
528 | // on a GNU/Linux system. *USED_NEXT_BLOCKER is set to indicate | |
529 | // whether the function took over NEXT_BLOCKER. | |
dbe717ef ILT |
530 | |
531 | bool | |
15f8229b | 532 | read_input_script(Workqueue*, Symbol_table*, Layout*, Dirsearch*, int, |
f1ed28fb | 533 | Input_objects*, Mapfile*, Input_group*, |
da769d56 ILT |
534 | const Input_argument*, Input_file*, |
535 | Task_token* next_blocker, bool* used_next_blocker); | |
dbe717ef | 536 | |
3c2fafa5 ILT |
537 | // FILE was found as an argument to --script (-T). |
538 | // Read it as a script, and execute its contents immediately. | |
539 | ||
540 | bool | |
c82fbeee | 541 | read_commandline_script(const char* filename, Command_line* cmdline); |
3c2fafa5 | 542 | |
09124467 ILT |
543 | // FILE was found as an argument to --version-script. Read it as a |
544 | // version script, and store its contents in | |
545 | // cmdline->script_options()->version_script_info(). | |
546 | ||
547 | bool | |
548 | read_version_script(const char* filename, Command_line* cmdline); | |
549 | ||
c82fbeee CS |
550 | // FILENAME was found as an argument to --dynamic-list. Read it as a |
551 | // version script (actually, a versym_node from a version script), and | |
552 | // store its contents in DYNAMIC_LIST. | |
553 | ||
554 | bool | |
555 | read_dynamic_list(const char* filename, Command_line* cmdline, | |
556 | Script_options* dynamic_list); | |
557 | ||
dbe717ef ILT |
558 | } // End namespace gold. |
559 | ||
560 | #endif // !defined(GOLD_SCRIPT_H) |