gdb/psympriv.h

   1 /* Private partial symbol table definitions.
   2
   3    Copyright (C) 2009-2021 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef PSYMPRIV_H
  21 #define PSYMPRIV_H
  22
  23 #include "psymtab.h"
  24 #include "objfiles.h"
  25 #include "gdbsupport/gdb_string_view.h"
  26
  27 /* A partial_symbol records the name, domain, and address class of
  28    symbols whose types we have not parsed yet.  For functions, it also
  29    contains their memory address, so we can find them from a PC value.
  30    Each partial_symbol sits in a partial_symtab, all of which are chained
  31    on a  partial symtab list and which points to the corresponding
  32    normal symtab once the partial_symtab has been referenced.  */
  33
  34 /* This structure is space critical.  See space comments at the top of
  35    symtab.h.  */
  36
  37 struct partial_symbol
  38 {
  39   /* Return the section for this partial symbol, or nullptr if no
  40      section has been set.  */
  41   struct obj_section *obj_section (struct objfile *objfile) const
  42   {
  43     return ginfo.obj_section (objfile);
  44   }
  45
  46   /* Return the unrelocated address of this partial symbol.  */
  47   CORE_ADDR unrelocated_address () const
  48   {
  49     return ginfo.value.address;
  50   }
  51
  52   /* Return the address of this partial symbol, relocated according to
  53      the offsets provided in OBJFILE.  */
  54   CORE_ADDR address (const struct objfile *objfile) const
  55   {
  56     return (ginfo.value.address
  57             + objfile->section_offsets[ginfo.section_index ()]);
  58   }
  59
  60   /* Set the address of this partial symbol.  The address must be
  61      unrelocated.  */
  62   void set_unrelocated_address (CORE_ADDR addr)
  63   {
  64     ginfo.value.address = addr;
  65   }
  66
  67   /* Note that partial_symbol does not derive from general_symbol_info
  68      due to the bcache.  See add_psymbol_to_bcache.  */
  69
  70   struct general_symbol_info ginfo;
  71
  72   /* Name space code.  */
  73
  74   ENUM_BITFIELD(domain_enum_tag) domain : SYMBOL_DOMAIN_BITS;
  75
  76   /* Address class (for info_symbols).  Note that we don't allow
  77      synthetic "aclass" values here at present, simply because there's
  78      no need.  */
  79
  80   ENUM_BITFIELD(address_class) aclass : SYMBOL_ACLASS_BITS;
  81 };
  82
  83 /* A convenience enum to give names to some constants used when
  84    searching psymtabs.  This is internal to psymtab and should not be
  85    used elsewhere.  */
  86
  87 enum psymtab_search_status
  88   {
  89     PST_NOT_SEARCHED,
  90     PST_SEARCHED_AND_FOUND,
  91     PST_SEARCHED_AND_NOT_FOUND
  92   };
  93
  94 /* Specify whether a partial psymbol should be allocated on the global
  95    list or the static list.  */
  96
  97 enum class psymbol_placement
  98 {
  99   STATIC,
 100   GLOBAL
 101 };
 102
 103 /* Each source file that has not been fully read in is represented by
 104    a partial_symtab.  This contains the information on where in the
 105    executable the debugging symbols for a specific file are, and a
 106    list of names of global symbols which are located in this file.
 107    They are all chained on partial symtab lists.
 108
 109    Even after the source file has been read into a symtab, the
 110    partial_symtab remains around.  */
 111
 112 struct partial_symtab
 113 {
 114   /* Allocate a new partial symbol table.
 115
 116      FILENAME (which must be non-NULL) is the filename of this partial
 117      symbol table; it is copied into the appropriate storage.  The
 118      partial symtab will also be installed using
 119      psymtab_storage::install.  */
 120
 121   partial_symtab (const char *filename,
 122                   psymtab_storage *partial_symtabs,
 123                   objfile_per_bfd_storage *objfile_per_bfd)
 124     ATTRIBUTE_NONNULL (2) ATTRIBUTE_NONNULL (3);
 125
 126   /* Like the above, but also sets the initial text low and text high
 127      from the ADDR argument, and sets the global- and
 128      static-offsets.  */
 129
 130   partial_symtab (const char *filename,
 131                   psymtab_storage *partial_symtabs,
 132                   objfile_per_bfd_storage *objfile_per_bfd,
 133                   CORE_ADDR addr)
 134     ATTRIBUTE_NONNULL (2) ATTRIBUTE_NONNULL (3);
 135
 136   virtual ~partial_symtab ()
 137   {
 138   }
 139
 140   /* Psymtab expansion is done in two steps:
 141      - a call to read_symtab
 142      - while that call is in progress, calls to expand_psymtab can be made,
 143        both for this psymtab, and its dependencies.
 144      This makes a distinction between a toplevel psymtab (for which both
 145      read_symtab and expand_psymtab will be called) and a non-toplevel
 146      psymtab (for which only expand_psymtab will be called). The
 147      distinction can be used f.i. to do things before and after all
 148      dependencies of a top-level psymtab have been expanded.
 149
 150      Read the full symbol table corresponding to this partial symbol
 151      table.  Typically calls expand_psymtab.  */
 152   virtual void read_symtab (struct objfile *) = 0;
 153
 154   /* Expand the full symbol table for this partial symbol table.  Typically
 155      calls expand_dependencies.  */
 156   virtual void expand_psymtab (struct objfile *) = 0;
 157
 158   /* Ensure that all the dependencies are read in.  Calls
 159      expand_psymtab for each non-shared dependency.  */
 160   void expand_dependencies (struct objfile *);
 161
 162   /* Return true if the symtab corresponding to this psymtab has been
 163      read in in the context of this objfile.  */
 164   virtual bool readin_p (struct objfile *) const = 0;
 165
 166   /* Return a pointer to the compunit allocated for this source file
 167      in the context of this objfile.
 168
 169      Return nullptr if the compunit was not read in or if there was no
 170      symtab.  */
 171   virtual struct compunit_symtab *get_compunit_symtab
 172     (struct objfile *) const = 0;
 173
 174   /* Return the raw low text address of this partial_symtab.  */
 175   CORE_ADDR raw_text_low () const
 176   {
 177     return m_text_low;
 178   }
 179
 180   /* Return the raw high text address of this partial_symtab.  */
 181   CORE_ADDR raw_text_high () const
 182   {
 183     return m_text_high;
 184   }
 185
 186   /* Return the relocated low text address of this partial_symtab.  */
 187   CORE_ADDR text_low (struct objfile *objfile) const
 188   {
 189     return m_text_low + objfile->text_section_offset ();
 190   }
 191
 192   /* Return the relocated high text address of this partial_symtab.  */
 193   CORE_ADDR text_high (struct objfile *objfile) const
 194   {
 195     return m_text_high + objfile->text_section_offset ();
 196   }
 197
 198   /* Set the low text address of this partial_symtab.  */
 199   void set_text_low (CORE_ADDR addr)
 200   {
 201     m_text_low = addr;
 202     text_low_valid = 1;
 203   }
 204
 205   /* Set the hight text address of this partial_symtab.  */
 206   void set_text_high (CORE_ADDR addr)
 207   {
 208     m_text_high = addr;
 209     text_high_valid = 1;
 210   }
 211
 212   /* Return true if this symtab is empty -- meaning that it contains
 213      no symbols.  It may still have dependencies.  */
 214   bool empty () const
 215   {
 216     return global_psymbols.empty () && static_psymbols.empty ();
 217   }
 218
 219   /* Add a symbol to this partial symbol table of OBJFILE.
 220
 221      If COPY_NAME is true, make a copy of NAME, otherwise use the passed
 222      reference.
 223
 224      THECLASS is the type of symbol.
 225
 226      SECTION is the index of the section of OBJFILE in which the symbol is found.
 227
 228      WHERE determines whether the symbol goes in the list of static or global
 229      partial symbols.
 230
 231      COREADDR is the address of the symbol.  For partial symbols that don't have
 232      an address, zero is passed.
 233
 234      LANGUAGE is the language from which the symbol originates.  This will
 235      influence, amongst other things, how the symbol name is demangled. */
 236
 237   void add_psymbol (gdb::string_view name,
 238                     bool copy_name, domain_enum domain,
 239                     enum address_class theclass,
 240                     short section,
 241                     psymbol_placement where,
 242                     CORE_ADDR coreaddr,
 243                     enum language language,
 244                     psymtab_storage *partial_symtabs,
 245                     struct objfile *objfile);
 246
 247   /* Add a symbol to this partial symbol table of OBJFILE.  The psymbol
 248      must be fully constructed, and the names must be set and intern'd
 249      as appropriate.  */
 250
 251   void add_psymbol (const partial_symbol &psym,
 252                     psymbol_placement where,
 253                     psymtab_storage *partial_symtabs,
 254                     struct objfile *objfile);
 255
 256
 257   /* Indicate that this partial symtab is complete.  */
 258
 259   void end ();
 260
 261   /* Chain of all existing partial symtabs.  */
 262
 263   struct partial_symtab *next = nullptr;
 264
 265   /* Name of the source file which this partial_symtab defines,
 266      or if the psymtab is anonymous then a descriptive name for
 267      debugging purposes, or "".  It must not be NULL.  */
 268
 269   const char *filename = nullptr;
 270
 271   /* Full path of the source file.  NULL if not known.  */
 272
 273   char *fullname = nullptr;
 274
 275   /* Directory in which it was compiled, or NULL if we don't know.  */
 276
 277   const char *dirname = nullptr;
 278
 279   /* Range of text addresses covered by this file; texthigh is the
 280      beginning of the next section.  Do not use if PSYMTABS_ADDRMAP_SUPPORTED
 281      is set.  Do not refer directly to these fields.  Instead, use the
 282      accessors.  The validity of these fields is determined by the
 283      text_low_valid and text_high_valid fields; these are located later
 284      in this structure for better packing.  */
 285
 286   CORE_ADDR m_text_low = 0;
 287   CORE_ADDR m_text_high = 0;
 288
 289   /* If NULL, this is an ordinary partial symbol table.
 290
 291      If non-NULL, this holds a single includer of this partial symbol
 292      table, and this partial symbol table is a shared one.
 293
 294      A shared psymtab is one that is referenced by multiple other
 295      psymtabs, and which conceptually has its contents directly
 296      included in those.
 297
 298      Shared psymtabs have special semantics.  When a search finds a
 299      symbol in a shared table, we instead return one of the non-shared
 300      tables that include this one.
 301
 302      A shared psymtabs can be referred to by other shared ones.
 303
 304      The psymtabs that refer to a shared psymtab will list the shared
 305      psymtab in their 'dependencies' array.
 306
 307      In DWARF terms, a shared psymtab is a DW_TAG_partial_unit; but
 308      of course using a name based on that would be too confusing, so
 309      "shared" was chosen instead.
 310
 311      Only a single user is needed because, when expanding a shared
 312      psymtab, we only need to expand its "canonical" non-shared user.
 313      The choice of which one should be canonical is left to the
 314      debuginfo reader; it can be arbitrary.  */
 315
 316   struct partial_symtab *user = nullptr;
 317
 318   /* Array of pointers to all of the partial_symtab's which this one
 319      depends on.  Since this array can only be set to previous or
 320      the current (?) psymtab, this dependency tree is guaranteed not
 321      to have any loops.  "depends on" means that symbols must be read
 322      for the dependencies before being read for this psymtab; this is
 323      for type references in stabs, where if foo.c includes foo.h, declarations
 324      in foo.h may use type numbers defined in foo.c.  For other debugging
 325      formats there may be no need to use dependencies.  */
 326
 327   struct partial_symtab **dependencies = nullptr;
 328
 329   int number_of_dependencies = 0;
 330
 331   /* Global symbol list.  This list will be sorted after readin to
 332      improve access.  Binary search will be the usual method of
 333      finding a symbol within it.  */
 334
 335   std::vector<partial_symbol *> global_psymbols;
 336
 337   /* Static symbol list.  This list will *not* be sorted after readin;
 338      to find a symbol in it, exhaustive search must be used.  This is
 339      reasonable because searches through this list will eventually
 340      lead to either the read in of a files symbols for real (assumed
 341      to take a *lot* of time; check) or an error (and we don't care
 342      how long errors take).  */
 343
 344   std::vector<partial_symbol *> static_psymbols;
 345
 346   /* True iff objfile->psymtabs_addrmap is properly populated for this
 347      partial_symtab.  For discontiguous overlapping psymtabs is the only usable
 348      info in PSYMTABS_ADDRMAP.  */
 349
 350   bool psymtabs_addrmap_supported = false;
 351
 352   /* True if the name of this partial symtab is not a source file name.  */
 353
 354   bool anonymous = false;
 355
 356   /* A flag that is temporarily used when searching psymtabs.  */
 357
 358   ENUM_BITFIELD (psymtab_search_status) searched_flag : 2;
 359
 360   /* Validity of the m_text_low and m_text_high fields.  */
 361
 362   unsigned int text_low_valid : 1;
 363   unsigned int text_high_valid : 1;
 364 };
 365
 366 /* A partial symtab that tracks the "readin" and "compunit_symtab"
 367    information in the ordinary way -- by storing it directly in this
 368    object.  */
 369 struct standard_psymtab : public partial_symtab
 370 {
 371   standard_psymtab (const char *filename,
 372                     psymtab_storage *partial_symtabs,
 373                     objfile_per_bfd_storage *objfile_per_bfd)
 374     : partial_symtab (filename, partial_symtabs, objfile_per_bfd)
 375   {
 376   }
 377
 378   standard_psymtab (const char *filename,
 379                     psymtab_storage *partial_symtabs,
 380                     objfile_per_bfd_storage *objfile_per_bfd,
 381                     CORE_ADDR addr)
 382     : partial_symtab (filename, partial_symtabs, objfile_per_bfd, addr)
 383   {
 384   }
 385
 386   bool readin_p (struct objfile *) const override
 387   {
 388     return readin;
 389   }
 390
 391   struct compunit_symtab *get_compunit_symtab (struct objfile *) const override
 392   {
 393     return compunit_symtab;
 394   }
 395
 396   /* True if the symtab corresponding to this psymtab has been
 397      readin.  */
 398
 399   bool readin = false;
 400
 401   /* Pointer to compunit eventually allocated for this source file, 0 if
 402      !readin or if we haven't looked for the symtab after it was readin.  */
 403
 404   struct compunit_symtab *compunit_symtab = nullptr;
 405 };
 406
 407 /* A partial_symtab that works in the historical db way.  This should
 408    not be used in new code, but exists to transition the somewhat
 409    unmaintained "legacy" debug formats.  */
 410
 411 struct legacy_psymtab : public standard_psymtab
 412 {
 413   legacy_psymtab (const char *filename,
 414                   psymtab_storage *partial_symtabs,
 415                   objfile_per_bfd_storage *objfile_per_bfd)
 416     : standard_psymtab (filename, partial_symtabs, objfile_per_bfd)
 417   {
 418   }
 419
 420   legacy_psymtab (const char *filename,
 421                   psymtab_storage *partial_symtabs,
 422                   objfile_per_bfd_storage *objfile_per_bfd,
 423                   CORE_ADDR addr)
 424     : standard_psymtab (filename, partial_symtabs, objfile_per_bfd, addr)
 425   {
 426   }
 427
 428   void read_symtab (struct objfile *objf) override
 429   {
 430     if (legacy_read_symtab)
 431       (*legacy_read_symtab) (this, objf);
 432   }
 433
 434   void expand_psymtab (struct objfile *objf) override
 435   {
 436     (*legacy_expand_psymtab) (this, objf);
 437   }
 438
 439   /* Pointer to function which will read in the symtab corresponding to
 440      this psymtab.  */
 441
 442   void (*legacy_read_symtab) (legacy_psymtab *, struct objfile *) = nullptr;
 443
 444   /* Pointer to function which will actually expand this psymtab into
 445      a full symtab.  */
 446
 447   void (*legacy_expand_psymtab) (legacy_psymtab *, struct objfile *) = nullptr;
 448
 449   /* Information that lets read_symtab() locate the part of the symbol table
 450      that this psymtab corresponds to.  This information is private to the
 451      format-dependent symbol reading routines.  For further detail examine
 452      the various symbol reading modules.  */
 453
 454   void *read_symtab_private = nullptr;
 455 };
 456
 457 /* Used when recording partial symbol tables.  On destruction,
 458    discards any partial symbol tables that have been built.  However,
 459    the tables can be kept by calling the "keep" method.  */
 460 class psymtab_discarder
 461 {
 462  public:
 463
 464   psymtab_discarder (psymtab_storage *partial_symtabs)
 465     : m_partial_symtabs (partial_symtabs),
 466       m_psymtab (partial_symtabs->psymtabs)
 467   {
 468   }
 469
 470   ~psymtab_discarder ()
 471   {
 472     if (m_partial_symtabs != nullptr)
 473       m_partial_symtabs->discard_psymtabs_to (m_psymtab);
 474   }
 475
 476   /* Keep any partial symbol tables that were built.  */
 477   void keep ()
 478   {
 479     m_partial_symtabs = nullptr;
 480   }
 481
 482  private:
 483
 484   /* The partial symbol storage object.  */
 485   psymtab_storage *m_partial_symtabs;
 486   /* How far back to free.  */
 487   struct partial_symtab *m_psymtab;
 488 };
 489
 490 /* An implementation of quick_symbol_functions, specialized for
 491    partial symbols.  */
 492 struct psymbol_functions : public quick_symbol_functions
 493 {
 494   explicit psymbol_functions (const std::shared_ptr<psymtab_storage> &storage)
 495     : m_partial_symtabs (storage)
 496   {
 497   }
 498
 499   psymbol_functions ()
 500     : m_partial_symtabs (new psymtab_storage)
 501   {
 502   }
 503
 504   bool has_symbols (struct objfile *objfile) override;
 505
 506   struct symtab *find_last_source_symtab (struct objfile *objfile) override;
 507
 508   void forget_cached_source_info (struct objfile *objfile) override;
 509
 510   enum language lookup_global_symbol_language (struct objfile *objfile,
 511                                                const char *name,
 512                                                domain_enum domain,
 513                                                bool *symbol_found_p) override;
 514
 515   void print_stats (struct objfile *objfile, bool print_bcache) override;
 516
 517   void dump (struct objfile *objfile) override;
 518
 519   void expand_all_symtabs (struct objfile *objfile) override;
 520
 521   void expand_matching_symbols
 522     (struct objfile *,
 523      const lookup_name_info &lookup_name,
 524      domain_enum domain,
 525      int global,
 526      symbol_compare_ftype *ordered_compare) override;
 527
 528   bool expand_symtabs_matching
 529     (struct objfile *objfile,
 530      gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher,
 531      const lookup_name_info *lookup_name,
 532      gdb::function_view<expand_symtabs_symbol_matcher_ftype> symbol_matcher,
 533      gdb::function_view<expand_symtabs_exp_notify_ftype> expansion_notify,
 534      block_search_flags search_flags,
 535      domain_enum domain,
 536      enum search_domain kind) override;
 537
 538   struct compunit_symtab *find_pc_sect_compunit_symtab
 539     (struct objfile *objfile, struct bound_minimal_symbol msymbol,
 540      CORE_ADDR pc, struct obj_section *section, int warn_if_readin) override;
 541
 542   struct compunit_symtab *find_compunit_symtab_by_address
 543     (struct objfile *objfile, CORE_ADDR address) override;
 544
 545   void map_symbol_filenames (struct objfile *objfile,
 546                              gdb::function_view<symbol_filename_ftype> fun,
 547                              bool need_fullname) override;
 548
 549   void relocated () override
 550   {
 551     m_psymbol_map.clear ();
 552   }
 553
 554   /* Ensure the partial symbols for OBJFILE have been loaded.  Return
 555      a range adapter for the psymtabs.  */
 556   psymtab_storage::partial_symtab_range require_partial_symbols
 557        (struct objfile *objfile);
 558
 559   /* Return the partial symbol storage associated with this
 560      object.  */
 561   const std::shared_ptr<psymtab_storage> &get_partial_symtabs () const
 562   {
 563     return m_partial_symtabs;
 564   }
 565
 566   /* Replace the partial symbol table storage in this object with
 567      SYMS.  */
 568   void set_partial_symtabs (const std::shared_ptr<psymtab_storage> &syms)
 569   {
 570     m_partial_symtabs = syms;
 571   }
 572
 573   /* Find which partial symtab contains PC and SECTION.  Return NULL if
 574      none.  We return the psymtab that contains a symbol whose address
 575      exactly matches PC, or, if we cannot find an exact match, the
 576      psymtab that contains a symbol whose address is closest to PC.  */
 577
 578   struct partial_symtab *find_pc_sect_psymtab
 579        (struct objfile *objfile,
 580         CORE_ADDR pc,
 581         struct obj_section *section,
 582         struct bound_minimal_symbol msymbol);
 583
 584 private:
 585
 586   /* Count the number of partial symbols in *THIS.  */
 587   int count_psyms ();
 588
 589   void fill_psymbol_map (struct objfile *objfile,
 590                          struct partial_symtab *psymtab,
 591                          std::set<CORE_ADDR> *seen_addrs,
 592                          const std::vector<partial_symbol *> &symbols);
 593
 594   /* Storage for the partial symbols.  */
 595   std::shared_ptr<psymtab_storage> m_partial_symtabs;
 596
 597   /* Map symbol addresses to the partial symtab that defines the
 598      object at that address.  */
 599
 600   std::vector<std::pair<CORE_ADDR, partial_symtab *>> m_psymbol_map;
 601 };
 602
 603 #endif /* PSYMPRIV_H */