1 /* Definitions for symbol file management in GDB. 2 3 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 4 2002, 2003, 2004, 2007, 2008, 2009, 2010, 2011 5 Free Software Foundation, Inc. 6 7 This file is part of GDB. 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 3 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 21 22 #if !defined (OBJFILES_H) 23 #define OBJFILES_H 24 25 #include "gdb_obstack.h" /* For obstack internals. */ 26 #include "symfile.h" /* For struct psymbol_allocation_list. */ 27 #include "progspace.h" 28 29 struct bcache; 30 struct htab; 31 struct symtab; 32 struct objfile_data; 33 34 /* This structure maintains information on a per-objfile basis about the 35 "entry point" of the objfile, and the scope within which the entry point 36 exists. It is possible that gdb will see more than one objfile that is 37 executable, each with its own entry point. 38 39 For example, for dynamically linked executables in SVR4, the dynamic linker 40 code is contained within the shared C library, which is actually executable 41 and is run by the kernel first when an exec is done of a user executable 42 that is dynamically linked. The dynamic linker within the shared C library 43 then maps in the various program segments in the user executable and jumps 44 to the user executable's recorded entry point, as if the call had been made 45 directly by the kernel. 46 47 The traditional gdb method of using this info was to use the 48 recorded entry point to set the entry-file's lowpc and highpc from 49 the debugging information, where these values are the starting 50 address (inclusive) and ending address (exclusive) of the 51 instruction space in the executable which correspond to the 52 "startup file", i.e. crt0.o in most cases. This file is assumed to 53 be a startup file and frames with pc's inside it are treated as 54 nonexistent. Setting these variables is necessary so that 55 backtraces do not fly off the bottom of the stack. 56 57 NOTE: cagney/2003-09-09: It turns out that this "traditional" 58 method doesn't work. Corinna writes: ``It turns out that the call 59 to test for "inside entry file" destroys a meaningful backtrace 60 under some conditions. E.g. the backtrace tests in the asm-source 61 testcase are broken for some targets. In this test the functions 62 are all implemented as part of one file and the testcase is not 63 necessarily linked with a start file (depending on the target). 64 What happens is, that the first frame is printed normaly and 65 following frames are treated as being inside the enttry file then. 66 This way, only the #0 frame is printed in the backtrace output.'' 67 Ref "frame.c" "NOTE: vinschen/2003-04-01". 68 69 Gdb also supports an alternate method to avoid running off the bottom 70 of the stack. 71 72 There are two frames that are "special", the frame for the function 73 containing the process entry point, since it has no predecessor frame, 74 and the frame for the function containing the user code entry point 75 (the main() function), since all the predecessor frames are for the 76 process startup code. Since we have no guarantee that the linked 77 in startup modules have any debugging information that gdb can use, 78 we need to avoid following frame pointers back into frames that might 79 have been built in the startup code, as we might get hopelessly 80 confused. However, we almost always have debugging information 81 available for main(). 82 83 These variables are used to save the range of PC values which are 84 valid within the main() function and within the function containing 85 the process entry point. If we always consider the frame for 86 main() as the outermost frame when debugging user code, and the 87 frame for the process entry point function as the outermost frame 88 when debugging startup code, then all we have to do is have 89 DEPRECATED_FRAME_CHAIN_VALID return false whenever a frame's 90 current PC is within the range specified by these variables. In 91 essence, we set "ceilings" in the frame chain beyond which we will 92 not proceed when following the frame chain back up the stack. 93 94 A nice side effect is that we can still debug startup code without 95 running off the end of the frame chain, assuming that we have usable 96 debugging information in the startup modules, and if we choose to not 97 use the block at main, or can't find it for some reason, everything 98 still works as before. And if we have no startup code debugging 99 information but we do have usable information for main(), backtraces 100 from user code don't go wandering off into the startup code. */ 101 102 struct entry_info 103 { 104 /* The relocated value we should use for this objfile entry point. */ 105 CORE_ADDR entry_point; 106 107 /* Set to 1 iff ENTRY_POINT contains a valid value. */ 108 unsigned entry_point_p : 1; 109 }; 110 111 /* Sections in an objfile. The section offsets are stored in the 112 OBJFILE. */ 113 114 struct obj_section 115 { 116 struct bfd_section *the_bfd_section; /* BFD section pointer */ 117 118 /* Objfile this section is part of. */ 119 struct objfile *objfile; 120 121 /* True if this "overlay section" is mapped into an "overlay region". */ 122 int ovly_mapped; 123 }; 124 125 /* Relocation offset applied to S. */ 126 #define obj_section_offset(s) \ 127 (((s)->objfile->section_offsets)->offsets[(s)->the_bfd_section->index]) 128 129 /* The memory address of section S (vma + offset). */ 130 #define obj_section_addr(s) \ 131 (bfd_get_section_vma ((s)->objfile->abfd, s->the_bfd_section) \ 132 + obj_section_offset (s)) 133 134 /* The one-passed-the-end memory address of section S 135 (vma + size + offset). */ 136 #define obj_section_endaddr(s) \ 137 (bfd_get_section_vma ((s)->objfile->abfd, s->the_bfd_section) \ 138 + bfd_get_section_size ((s)->the_bfd_section) \ 139 + obj_section_offset (s)) 140 141 /* The "objstats" structure provides a place for gdb to record some 142 interesting information about its internal state at runtime, on a 143 per objfile basis, such as information about the number of symbols 144 read, size of string table (if any), etc. */ 145 146 struct objstats 147 { 148 int n_minsyms; /* Number of minimal symbols read */ 149 int n_psyms; /* Number of partial symbols read */ 150 int n_syms; /* Number of full symbols read */ 151 int n_stabs; /* Number of ".stabs" read (if applicable) */ 152 int n_types; /* Number of types */ 153 int sz_strtab; /* Size of stringtable, (if applicable) */ 154 }; 155 156 #define OBJSTAT(objfile, expr) (objfile -> stats.expr) 157 #define OBJSTATS struct objstats stats 158 extern void print_objfile_statistics (void); 159 extern void print_symbol_bcache_statistics (void); 160 161 /* Number of entries in the minimal symbol hash table. */ 162 #define MINIMAL_SYMBOL_HASH_SIZE 2039 163 164 /* Master structure for keeping track of each file from which 165 gdb reads symbols. There are several ways these get allocated: 1. 166 The main symbol file, symfile_objfile, set by the symbol-file command, 167 2. Additional symbol files added by the add-symbol-file command, 168 3. Shared library objfiles, added by ADD_SOLIB, 4. symbol files 169 for modules that were loaded when GDB attached to a remote system 170 (see remote-vx.c). */ 171 172 struct objfile 173 { 174 175 /* All struct objfile's are chained together by their next pointers. 176 The global variable "object_files" points to the first link in this 177 chain. 178 179 FIXME: There is a problem here if the objfile is reusable, and if 180 multiple users are to be supported. The problem is that the objfile 181 list is linked through a member of the objfile struct itself, which 182 is only valid for one gdb process. The list implementation needs to 183 be changed to something like: 184 185 struct list {struct list *next; struct objfile *objfile}; 186 187 where the list structure is completely maintained separately within 188 each gdb process. */ 189 190 struct objfile *next; 191 192 /* The object file's name, tilde-expanded and absolute. Malloc'd; free it 193 if you free this struct. This pointer is never NULL. */ 194 195 char *name; 196 197 CORE_ADDR addr_low; 198 199 /* Some flag bits for this objfile. */ 200 201 unsigned short flags; 202 203 /* The program space associated with this objfile. */ 204 205 struct program_space *pspace; 206 207 /* Each objfile points to a linked list of symtabs derived from this file, 208 one symtab structure for each compilation unit (source file). Each link 209 in the symtab list contains a backpointer to this objfile. */ 210 211 struct symtab *symtabs; 212 213 /* Each objfile points to a linked list of partial symtabs derived from 214 this file, one partial symtab structure for each compilation unit 215 (source file). */ 216 217 struct partial_symtab *psymtabs; 218 219 /* Map addresses to the entries of PSYMTABS. It would be more efficient to 220 have a map per the whole process but ADDRMAP cannot selectively remove 221 its items during FREE_OBJFILE. This mapping is already present even for 222 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */ 223 224 struct addrmap *psymtabs_addrmap; 225 226 /* List of freed partial symtabs, available for re-use. */ 227 228 struct partial_symtab *free_psymtabs; 229 230 /* The object file's BFD. Can be null if the objfile contains only 231 minimal symbols, e.g. the run time common symbols for SunOS4. */ 232 233 bfd *obfd; 234 235 /* The gdbarch associated with the BFD. Note that this gdbarch is 236 determined solely from BFD information, without looking at target 237 information. The gdbarch determined from a running target may 238 differ from this e.g. with respect to register types and names. */ 239 240 struct gdbarch *gdbarch; 241 242 /* The modification timestamp of the object file, as of the last time 243 we read its symbols. */ 244 245 long mtime; 246 247 /* Obstack to hold objects that should be freed when we load a new symbol 248 table from this object file. */ 249 250 struct obstack objfile_obstack; 251 252 /* A byte cache where we can stash arbitrary "chunks" of bytes that 253 will not change. */ 254 255 struct psymbol_bcache *psymbol_cache; /* Byte cache for partial syms. */ 256 struct bcache *macro_cache; /* Byte cache for macros. */ 257 struct bcache *filename_cache; /* Byte cache for file names. */ 258 259 /* Hash table for mapping symbol names to demangled names. Each 260 entry in the hash table is actually two consecutive strings, 261 both null-terminated; the first one is a mangled or linkage 262 name, and the second is the demangled name or just a zero byte 263 if the name doesn't demangle. */ 264 struct htab *demangled_names_hash; 265 266 /* Vectors of all partial symbols read in from file. The actual data 267 is stored in the objfile_obstack. */ 268 269 struct psymbol_allocation_list global_psymbols; 270 struct psymbol_allocation_list static_psymbols; 271 272 /* Each file contains a pointer to an array of minimal symbols for all 273 global symbols that are defined within the file. The array is 274 terminated by a "null symbol", one that has a NULL pointer for the 275 name and a zero value for the address. This makes it easy to walk 276 through the array when passed a pointer to somewhere in the middle 277 of it. There is also a count of the number of symbols, which does 278 not include the terminating null symbol. The array itself, as well 279 as all the data that it points to, should be allocated on the 280 objfile_obstack for this file. */ 281 282 struct minimal_symbol *msymbols; 283 int minimal_symbol_count; 284 285 /* This is a hash table used to index the minimal symbols by name. */ 286 287 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE]; 288 289 /* This hash table is used to index the minimal symbols by their 290 demangled names. */ 291 292 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE]; 293 294 /* Structure which keeps track of functions that manipulate objfile's 295 of the same type as this objfile. I.e. the function to read partial 296 symbols for example. Note that this structure is in statically 297 allocated memory, and is shared by all objfiles that use the 298 object module reader of this type. */ 299 300 const struct sym_fns *sf; 301 302 /* The per-objfile information about the entry point, the scope (file/func) 303 containing the entry point, and the scope of the user's main() func. */ 304 305 struct entry_info ei; 306 307 /* Information about stabs. Will be filled in with a dbx_symfile_info 308 struct by those readers that need it. */ 309 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile 310 data points implemented using "data" and "num_data" below. For 311 an example of how to use this replacement, see "objfile_data" 312 in "mips-tdep.c". */ 313 314 struct dbx_symfile_info *deprecated_sym_stab_info; 315 316 /* Hook for information for use by the symbol reader (currently used 317 for information shared by sym_init and sym_read). It is 318 typically a pointer to malloc'd memory. The symbol reader's finish 319 function is responsible for freeing the memory thusly allocated. */ 320 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile 321 data points implemented using "data" and "num_data" below. For 322 an example of how to use this replacement, see "objfile_data" 323 in "mips-tdep.c". */ 324 325 void *deprecated_sym_private; 326 327 /* Per objfile data-pointers required by other GDB modules. */ 328 /* FIXME: kettenis/20030711: This mechanism could replace 329 deprecated_sym_stab_info and deprecated_sym_private 330 entirely. */ 331 332 void **data; 333 unsigned num_data; 334 335 /* Set of relocation offsets to apply to each section. 336 Currently on the objfile_obstack (which makes no sense, but I'm 337 not sure it's harming anything). 338 339 These offsets indicate that all symbols (including partial and 340 minimal symbols) which have been read have been relocated by this 341 much. Symbols which are yet to be read need to be relocated by 342 it. */ 343 344 struct section_offsets *section_offsets; 345 int num_sections; 346 347 /* Indexes in the section_offsets array. These are initialized by the 348 *_symfile_offsets() family of functions (som_symfile_offsets, 349 xcoff_symfile_offsets, default_symfile_offsets). In theory they 350 should correspond to the section indexes used by bfd for the 351 current objfile. The exception to this for the time being is the 352 SOM version. */ 353 354 int sect_index_text; 355 int sect_index_data; 356 int sect_index_bss; 357 int sect_index_rodata; 358 359 /* These pointers are used to locate the section table, which 360 among other things, is used to map pc addresses into sections. 361 SECTIONS points to the first entry in the table, and 362 SECTIONS_END points to the first location past the last entry 363 in the table. Currently the table is stored on the 364 objfile_obstack (which makes no sense, but I'm not sure it's 365 harming anything). */ 366 367 struct obj_section 368 *sections, *sections_end; 369 370 /* GDB allows to have debug symbols in separate object files. This is 371 used by .gnu_debuglink, ELF build id note and Mach-O OSO. 372 Although this is a tree structure, GDB only support one level 373 (ie a separate debug for a separate debug is not supported). Note that 374 separate debug object are in the main chain and therefore will be 375 visited by ALL_OBJFILES & co iterators. Separate debug objfile always 376 has a non-nul separate_debug_objfile_backlink. */ 377 378 /* Link to the first separate debug object, if any. */ 379 struct objfile *separate_debug_objfile; 380 381 /* If this is a separate debug object, this is used as a link to the 382 actual executable objfile. */ 383 struct objfile *separate_debug_objfile_backlink; 384 385 /* If this is a separate debug object, this is a link to the next one 386 for the same executable objfile. */ 387 struct objfile *separate_debug_objfile_link; 388 389 /* Place to stash various statistics about this objfile. */ 390 OBJSTATS; 391 392 /* A symtab that the C++ code uses to stash special symbols 393 associated to namespaces. */ 394 395 /* FIXME/carlton-2003-06-27: Delete this in a few years once 396 "possible namespace symbols" go away. */ 397 struct symtab *cp_namespace_symtab; 398 399 /* A linked list of symbols created when reading template types or 400 function templates. These symbols are not stored in any symbol 401 table, so we have to keep them here to relocate them 402 properly. */ 403 struct symbol *template_symbols; 404 }; 405 406 /* Defines for the objfile flag word. */ 407 408 /* When an object file has its functions reordered (currently Irix-5.2 409 shared libraries exhibit this behaviour), we will need an expensive 410 algorithm to locate a partial symtab or symtab via an address. 411 To avoid this penalty for normal object files, we use this flag, 412 whose setting is determined upon symbol table read in. */ 413 414 #define OBJF_REORDERED (1 << 0) /* Functions are reordered */ 415 416 /* Distinguish between an objfile for a shared library and a "vanilla" 417 objfile. (If not set, the objfile may still actually be a solib. 418 This can happen if the user created the objfile by using the 419 add-symbol-file command. GDB doesn't in that situation actually 420 check whether the file is a solib. Rather, the target's 421 implementation of the solib interface is responsible for setting 422 this flag when noticing solibs used by an inferior.) */ 423 424 #define OBJF_SHARED (1 << 1) /* From a shared library */ 425 426 /* User requested that this objfile be read in it's entirety. */ 427 428 #define OBJF_READNOW (1 << 2) /* Immediate full read */ 429 430 /* This objfile was created because the user explicitly caused it 431 (e.g., used the add-symbol-file command). This bit offers a way 432 for run_command to remove old objfile entries which are no longer 433 valid (i.e., are associated with an old inferior), but to preserve 434 ones that the user explicitly loaded via the add-symbol-file 435 command. */ 436 437 #define OBJF_USERLOADED (1 << 3) /* User loaded */ 438 439 /* Set if we have tried to read partial symtabs for this objfile. 440 This is used to allow lazy reading of partial symtabs. */ 441 442 #define OBJF_PSYMTABS_READ (1 << 4) 443 444 /* The object file that contains the runtime common minimal symbols 445 for SunOS4. Note that this objfile has no associated BFD. */ 446 447 extern struct objfile *rt_common_objfile; 448 449 /* When we need to allocate a new type, we need to know which objfile_obstack 450 to allocate the type on, since there is one for each objfile. The places 451 where types are allocated are deeply buried in function call hierarchies 452 which know nothing about objfiles, so rather than trying to pass a 453 particular objfile down to them, we just do an end run around them and 454 set current_objfile to be whatever objfile we expect to be using at the 455 time types are being allocated. For instance, when we start reading 456 symbols for a particular objfile, we set current_objfile to point to that 457 objfile, and when we are done, we set it back to NULL, to ensure that we 458 never put a type someplace other than where we are expecting to put it. 459 FIXME: Maybe we should review the entire type handling system and 460 see if there is a better way to avoid this problem. */ 461 462 extern struct objfile *current_objfile; 463 464 /* Declarations for functions defined in objfiles.c */ 465 466 extern struct objfile *allocate_objfile (bfd *, int); 467 468 extern struct gdbarch *get_objfile_arch (struct objfile *); 469 470 extern void init_entry_point_info (struct objfile *); 471 472 extern int entry_point_address_query (CORE_ADDR *entry_p); 473 474 extern CORE_ADDR entry_point_address (void); 475 476 extern int build_objfile_section_table (struct objfile *); 477 478 extern void terminate_minimal_symbol_table (struct objfile *objfile); 479 480 extern struct objfile *objfile_separate_debug_iterate (const struct objfile *, 481 const struct objfile *); 482 483 extern void put_objfile_before (struct objfile *, struct objfile *); 484 485 extern void objfile_to_front (struct objfile *); 486 487 extern void add_separate_debug_objfile (struct objfile *, struct objfile *); 488 489 extern void unlink_objfile (struct objfile *); 490 491 extern void free_objfile (struct objfile *); 492 493 extern void free_objfile_separate_debug (struct objfile *); 494 495 extern struct cleanup *make_cleanup_free_objfile (struct objfile *); 496 497 extern void free_all_objfiles (void); 498 499 extern void objfile_relocate (struct objfile *, struct section_offsets *); 500 501 extern int objfile_has_partial_symbols (struct objfile *objfile); 502 503 extern int objfile_has_full_symbols (struct objfile *objfile); 504 505 extern int objfile_has_symbols (struct objfile *objfile); 506 507 extern int have_partial_symbols (void); 508 509 extern int have_full_symbols (void); 510 511 extern void objfiles_changed (void); 512 513 /* This operation deletes all objfile entries that represent solibs that 514 weren't explicitly loaded by the user, via e.g., the add-symbol-file 515 command. */ 516 517 extern void objfile_purge_solibs (void); 518 519 /* Functions for dealing with the minimal symbol table, really a misc 520 address<->symbol mapping for things we don't have debug symbols for. */ 521 522 extern int have_minimal_symbols (void); 523 524 extern struct obj_section *find_pc_section (CORE_ADDR pc); 525 526 extern int in_plt_section (CORE_ADDR, char *); 527 528 /* Keep a registry of per-objfile data-pointers required by other GDB 529 modules. */ 530 531 /* Allocate an entry in the per-objfile registry. */ 532 extern const struct objfile_data *register_objfile_data (void); 533 534 /* Allocate an entry in the per-objfile registry. 535 SAVE and FREE are called when clearing objfile data. 536 First all registered SAVE functions are called. 537 Then all registered FREE functions are called. 538 Either or both of SAVE, FREE may be NULL. */ 539 extern const struct objfile_data *register_objfile_data_with_cleanup 540 (void (*save) (struct objfile *, void *), 541 void (*free) (struct objfile *, void *)); 542 543 extern void clear_objfile_data (struct objfile *objfile); 544 extern void set_objfile_data (struct objfile *objfile, 545 const struct objfile_data *data, void *value); 546 extern void *objfile_data (struct objfile *objfile, 547 const struct objfile_data *data); 548 549 extern struct bfd *gdb_bfd_ref (struct bfd *abfd); 550 extern void gdb_bfd_unref (struct bfd *abfd); 551 extern int gdb_bfd_close_or_warn (struct bfd *abfd); 552 553 554 /* Traverse all object files in the current program space. 555 ALL_OBJFILES_SAFE works even if you delete the objfile during the 556 traversal. */ 557 558 /* Traverse all object files in program space SS. */ 559 560 #define ALL_PSPACE_OBJFILES(ss, obj) \ 561 for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next) \ 562 563 #define ALL_PSPACE_OBJFILES_SAFE(ss, obj, nxt) \ 564 for ((obj) = ss->objfiles; \ 565 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \ 566 (obj) = (nxt)) 567 568 #define ALL_OBJFILES(obj) \ 569 for ((obj) = current_program_space->objfiles; \ 570 (obj) != NULL; \ 571 (obj) = (obj)->next) 572 573 #define ALL_OBJFILES_SAFE(obj,nxt) \ 574 for ((obj) = current_program_space->objfiles; \ 575 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \ 576 (obj) = (nxt)) 577 578 /* Traverse all symtabs in one objfile. */ 579 580 #define ALL_OBJFILE_SYMTABS(objfile, s) \ 581 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next) 582 583 /* Traverse all minimal symbols in one objfile. */ 584 585 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \ 586 for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++) 587 588 /* Traverse all symtabs in all objfiles in the current symbol 589 space. */ 590 591 #define ALL_SYMTABS(objfile, s) \ 592 ALL_OBJFILES (objfile) \ 593 ALL_OBJFILE_SYMTABS (objfile, s) 594 595 #define ALL_PSPACE_SYMTABS(ss, objfile, s) \ 596 ALL_PSPACE_OBJFILES (ss, objfile) \ 597 ALL_OBJFILE_SYMTABS (objfile, s) 598 599 /* Traverse all symtabs in all objfiles in the current program space, 600 skipping included files (which share a blockvector with their 601 primary symtab). */ 602 603 #define ALL_PRIMARY_SYMTABS(objfile, s) \ 604 ALL_OBJFILES (objfile) \ 605 ALL_OBJFILE_SYMTABS (objfile, s) \ 606 if ((s)->primary) 607 608 #define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s) \ 609 ALL_PSPACE_OBJFILES (ss, objfile) \ 610 ALL_OBJFILE_SYMTABS (objfile, s) \ 611 if ((s)->primary) 612 613 /* Traverse all minimal symbols in all objfiles in the current symbol 614 space. */ 615 616 #define ALL_MSYMBOLS(objfile, m) \ 617 ALL_OBJFILES (objfile) \ 618 ALL_OBJFILE_MSYMBOLS (objfile, m) 619 620 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \ 621 for (osect = objfile->sections; osect < objfile->sections_end; osect++) 622 623 /* Traverse all obj_sections in all objfiles in the current program 624 space. 625 626 Note that this detects a "break" in the inner loop, and exits 627 immediately from the outer loop as well, thus, client code doesn't 628 need to know that this is implemented with a double for. The extra 629 hair is to make sure that a "break;" stops the outer loop iterating 630 as well, and both OBJFILE and OSECT are left unmodified: 631 632 - The outer loop learns about the inner loop's end condition, and 633 stops iterating if it detects the inner loop didn't reach its 634 end. In other words, the outer loop keeps going only if the 635 inner loop reached its end cleanly [(osect) == 636 (objfile)->sections_end]. 637 638 - OSECT is initialized in the outer loop initialization 639 expressions, such as if the inner loop has reached its end, so 640 the check mentioned above succeeds the first time. 641 642 - The trick to not clearing OBJFILE on a "break;" is, in the outer 643 loop's loop expression, advance OBJFILE, but iff the inner loop 644 reached its end. If not, there was a "break;", so leave OBJFILE 645 as is; the outer loop's conditional will break immediately as 646 well (as OSECT will be different from OBJFILE->sections_end). */ 647 648 #define ALL_OBJSECTIONS(objfile, osect) \ 649 for ((objfile) = current_program_space->objfiles, \ 650 (objfile) != NULL ? ((osect) = (objfile)->sections_end) : 0; \ 651 (objfile) != NULL \ 652 && (osect) == (objfile)->sections_end; \ 653 ((osect) == (objfile)->sections_end \ 654 ? ((objfile) = (objfile)->next, \ 655 (objfile) != NULL ? (osect) = (objfile)->sections_end : 0) \ 656 : 0)) \ 657 for ((osect) = (objfile)->sections; \ 658 (osect) < (objfile)->sections_end; \ 659 (osect)++) 660 661 #define SECT_OFF_DATA(objfile) \ 662 ((objfile->sect_index_data == -1) \ 663 ? (internal_error (__FILE__, __LINE__, \ 664 _("sect_index_data not initialized")), -1) \ 665 : objfile->sect_index_data) 666 667 #define SECT_OFF_RODATA(objfile) \ 668 ((objfile->sect_index_rodata == -1) \ 669 ? (internal_error (__FILE__, __LINE__, \ 670 _("sect_index_rodata not initialized")), -1) \ 671 : objfile->sect_index_rodata) 672 673 #define SECT_OFF_TEXT(objfile) \ 674 ((objfile->sect_index_text == -1) \ 675 ? (internal_error (__FILE__, __LINE__, \ 676 _("sect_index_text not initialized")), -1) \ 677 : objfile->sect_index_text) 678 679 /* Sometimes the .bss section is missing from the objfile, so we don't 680 want to die here. Let the users of SECT_OFF_BSS deal with an 681 uninitialized section index. */ 682 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss 683 684 /* Answer whether there is more than one object file loaded. */ 685 686 #define MULTI_OBJFILE_P() (object_files && object_files->next) 687 688 #endif /* !defined (OBJFILES_H) */ 689