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 associated with OBJFILE.
 115      FILENAME (which must be non-NULL) is the filename of this partial
 116      symbol table; it is copied into the appropriate storage.  The
 117      partial symtab will also be installed using
 118      psymtab_storage::install.  */
 119
 120   partial_symtab (const char *filename,
 121                   psymtab_storage *partial_symtabs,
 122                   struct objfile *objfile)
 123     ATTRIBUTE_NONNULL (2) ATTRIBUTE_NONNULL (3);
 124
 125   /* Like the above, but also sets the initial text low and text high
 126      from the ADDR argument, and sets the global- and
 127      static-offsets.  */
 128
 129   partial_symtab (const char *filename,
 130                   psymtab_storage *partial_symtabs,
 131                   struct objfile *objfile,
 132                   CORE_ADDR addr)
 133     ATTRIBUTE_NONNULL (2) ATTRIBUTE_NONNULL (3);
 134
 135   virtual ~partial_symtab ()
 136   {
 137   }
 138
 139   /* Psymtab expansion is done in two steps:
 140      - a call to read_symtab
 141      - while that call is in progress, calls to expand_psymtab can be made,
 142        both for this psymtab, and its dependencies.
 143      This makes a distinction between a toplevel psymtab (for which both
 144      read_symtab and expand_psymtab will be called) and a non-toplevel
 145      psymtab (for which only expand_psymtab will be called). The
 146      distinction can be used f.i. to do things before and after all
 147      dependencies of a top-level psymtab have been expanded.
 148
 149      Read the full symbol table corresponding to this partial symbol
 150      table.  Typically calls expand_psymtab.  */
 151   virtual void read_symtab (struct objfile *) = 0;
 152
 153   /* Expand the full symbol table for this partial symbol table.  Typically
 154      calls expand_dependencies.  */
 155   virtual void expand_psymtab (struct objfile *) = 0;
 156
 157   /* Ensure that all the dependencies are read in.  Calls
 158      expand_psymtab for each non-shared dependency.  */
 159   void expand_dependencies (struct objfile *);
 160
 161   /* Return true if the symtab corresponding to this psymtab has been
 162      read in in the context of this objfile.  */
 163   virtual bool readin_p (struct objfile *) const = 0;
 164
 165   /* Return a pointer to the compunit allocated for this source file
 166      in the context of this objfile.
 167
 168      Return nullptr if the compunit was not read in or if there was no
 169      symtab.  */
 170   virtual struct compunit_symtab *get_compunit_symtab
 171     (struct objfile *) const = 0;
 172
 173   /* Return the raw low text address of this partial_symtab.  */
 174   CORE_ADDR raw_text_low () const
 175   {
 176     return m_text_low;
 177   }
 178
 179   /* Return the raw high text address of this partial_symtab.  */
 180   CORE_ADDR raw_text_high () const
 181   {
 182     return m_text_high;
 183   }
 184
 185   /* Return the relocated low text address of this partial_symtab.  */
 186   CORE_ADDR text_low (struct objfile *objfile) const
 187   {
 188     return m_text_low + objfile->text_section_offset ();
 189   }
 190
 191   /* Return the relocated high text address of this partial_symtab.  */
 192   CORE_ADDR text_high (struct objfile *objfile) const
 193   {
 194     return m_text_high + objfile->text_section_offset ();
 195   }
 196
 197   /* Set the low text address of this partial_symtab.  */
 198   void set_text_low (CORE_ADDR addr)
 199   {
 200     m_text_low = addr;
 201     text_low_valid = 1;
 202   }
 203
 204   /* Set the hight text address of this partial_symtab.  */
 205   void set_text_high (CORE_ADDR addr)
 206   {
 207     m_text_high = addr;
 208     text_high_valid = 1;
 209   }
 210
 211   /* Return true if this symtab is empty -- meaning that it contains
 212      no symbols.  It may still have dependencies.  */
 213   bool empty () const
 214   {
 215     return global_psymbols.empty () && static_psymbols.empty ();
 216   }
 217
 218   /* Add a symbol to this partial symbol table of OBJFILE.
 219
 220      If COPY_NAME is true, make a copy of NAME, otherwise use the passed
 221      reference.
 222
 223      THECLASS is the type of symbol.
 224
 225      SECTION is the index of the section of OBJFILE in which the symbol is found.
 226
 227      WHERE determines whether the symbol goes in the list of static or global
 228      partial symbols.
 229
 230      COREADDR is the address of the symbol.  For partial symbols that don't have
 231      an address, zero is passed.
 232
 233      LANGUAGE is the language from which the symbol originates.  This will
 234      influence, amongst other things, how the symbol name is demangled. */
 235
 236   void add_psymbol (gdb::string_view name,
 237                     bool copy_name, domain_enum domain,
 238                     enum address_class theclass,
 239                     short section,
 240                     psymbol_placement where,
 241                     CORE_ADDR coreaddr,
 242                     enum language language,
 243                     psymtab_storage *partial_symtabs,
 244                     struct objfile *objfile);
 245
 246   /* Add a symbol to this partial symbol table of OBJFILE.  The psymbol
 247      must be fully constructed, and the names must be set and intern'd
 248      as appropriate.  */
 249
 250   void add_psymbol (const partial_symbol &psym,
 251                     psymbol_placement where,
 252                     psymtab_storage *partial_symtabs,
 253                     struct objfile *objfile);
 254
 255
 256   /* Indicate that this partial symtab is complete.  */
 257
 258   void end ();
 259
 260   /* Chain of all existing partial symtabs.  */
 261
 262   struct partial_symtab *next = nullptr;
 263
 264   /* Name of the source file which this partial_symtab defines,
 265      or if the psymtab is anonymous then a descriptive name for
 266      debugging purposes, or "".  It must not be NULL.  */
 267
 268   const char *filename = nullptr;
 269
 270   /* Full path of the source file.  NULL if not known.  */
 271
 272   char *fullname = nullptr;
 273
 274   /* Directory in which it was compiled, or NULL if we don't know.  */
 275
 276   const char *dirname = nullptr;
 277
 278   /* Range of text addresses covered by this file; texthigh is the
 279      beginning of the next section.  Do not use if PSYMTABS_ADDRMAP_SUPPORTED
 280      is set.  Do not refer directly to these fields.  Instead, use the
 281      accessors.  The validity of these fields is determined by the
 282      text_low_valid and text_high_valid fields; these are located later
 283      in this structure for better packing.  */
 284
 285   CORE_ADDR m_text_low = 0;
 286   CORE_ADDR m_text_high = 0;
 287
 288   /* If NULL, this is an ordinary partial symbol table.
 289
 290      If non-NULL, this holds a single includer of this partial symbol
 291      table, and this partial symbol table is a shared one.
 292
 293      A shared psymtab is one that is referenced by multiple other
 294      psymtabs, and which conceptually has its contents directly
 295      included in those.
 296
 297      Shared psymtabs have special semantics.  When a search finds a
 298      symbol in a shared table, we instead return one of the non-shared
 299      tables that include this one.
 300
 301      A shared psymtabs can be referred to by other shared ones.
 302
 303      The psymtabs that refer to a shared psymtab will list the shared
 304      psymtab in their 'dependencies' array.
 305
 306      In DWARF terms, a shared psymtab is a DW_TAG_partial_unit; but
 307      of course using a name based on that would be too confusing, so
 308      "shared" was chosen instead.
 309
 310      Only a single user is needed because, when expanding a shared
 311      psymtab, we only need to expand its "canonical" non-shared user.
 312      The choice of which one should be canonical is left to the
 313      debuginfo reader; it can be arbitrary.  */
 314
 315   struct partial_symtab *user = nullptr;
 316
 317   /* Array of pointers to all of the partial_symtab's which this one
 318      depends on.  Since this array can only be set to previous or
 319      the current (?) psymtab, this dependency tree is guaranteed not
 320      to have any loops.  "depends on" means that symbols must be read
 321      for the dependencies before being read for this psymtab; this is
 322      for type references in stabs, where if foo.c includes foo.h, declarations
 323      in foo.h may use type numbers defined in foo.c.  For other debugging
 324      formats there may be no need to use dependencies.  */
 325
 326   struct partial_symtab **dependencies = nullptr;
 327
 328   int number_of_dependencies = 0;
 329
 330   /* Global symbol list.  This list will be sorted after readin to
 331      improve access.  Binary search will be the usual method of
 332      finding a symbol within it.  */
 333
 334   std::vector<partial_symbol *> global_psymbols;
 335
 336   /* Static symbol list.  This list will *not* be sorted after readin;
 337      to find a symbol in it, exhaustive search must be used.  This is
 338      reasonable because searches through this list will eventually
 339      lead to either the read in of a files symbols for real (assumed
 340      to take a *lot* of time; check) or an error (and we don't care
 341      how long errors take).  */
 342
 343   std::vector<partial_symbol *> static_psymbols;
 344
 345   /* True iff objfile->psymtabs_addrmap is properly populated for this
 346      partial_symtab.  For discontiguous overlapping psymtabs is the only usable
 347      info in PSYMTABS_ADDRMAP.  */
 348
 349   bool psymtabs_addrmap_supported = false;
 350
 351   /* True if the name of this partial symtab is not a source file name.  */
 352
 353   bool anonymous = false;
 354
 355   /* A flag that is temporarily used when searching psymtabs.  */
 356
 357   ENUM_BITFIELD (psymtab_search_status) searched_flag : 2;
 358
 359   /* Validity of the m_text_low and m_text_high fields.  */
 360
 361   unsigned int text_low_valid : 1;
 362   unsigned int text_high_valid : 1;
 363 };
 364
 365 /* A partial symtab that tracks the "readin" and "compunit_symtab"
 366    information in the ordinary way -- by storing it directly in this
 367    object.  */
 368 struct standard_psymtab : public partial_symtab
 369 {
 370   standard_psymtab (const char *filename,
 371                     psymtab_storage *partial_symtabs,
 372                     struct objfile *objfile)
 373     : partial_symtab (filename, partial_symtabs, objfile)
 374   {
 375   }
 376
 377   standard_psymtab (const char *filename,
 378                     psymtab_storage *partial_symtabs,
 379                     struct objfile *objfile,
 380                     CORE_ADDR addr)
 381     : partial_symtab (filename, partial_symtabs, objfile, addr)
 382   {
 383   }
 384
 385   bool readin_p (struct objfile *) const override
 386   {
 387     return readin;
 388   }
 389
 390   struct compunit_symtab *get_compunit_symtab (struct objfile *) const override
 391   {
 392     return compunit_symtab;
 393   }
 394
 395   /* True if the symtab corresponding to this psymtab has been
 396      readin.  */
 397
 398   bool readin = false;
 399
 400   /* Pointer to compunit eventually allocated for this source file, 0 if
 401      !readin or if we haven't looked for the symtab after it was readin.  */
 402
 403   struct compunit_symtab *compunit_symtab = nullptr;
 404 };
 405
 406 /* A partial_symtab that works in the historical db way.  This should
 407    not be used in new code, but exists to transition the somewhat
 408    unmaintained "legacy" debug formats.  */
 409
 410 struct legacy_psymtab : public standard_psymtab
 411 {
 412   legacy_psymtab (const char *filename,
 413                   psymtab_storage *partial_symtabs,
 414                   struct objfile *objfile)
 415     : standard_psymtab (filename, partial_symtabs, objfile)
 416   {
 417   }
 418
 419   legacy_psymtab (const char *filename,
 420                   psymtab_storage *partial_symtabs,
 421                   struct objfile *objfile,
 422                   CORE_ADDR addr)
 423     : standard_psymtab (filename, partial_symtabs, objfile, addr)
 424   {
 425   }
 426
 427   void read_symtab (struct objfile *objf) override
 428   {
 429     if (legacy_read_symtab)
 430       (*legacy_read_symtab) (this, objf);
 431   }
 432
 433   void expand_psymtab (struct objfile *objf) override
 434   {
 435     (*legacy_expand_psymtab) (this, objf);
 436   }
 437
 438   /* Pointer to function which will read in the symtab corresponding to
 439      this psymtab.  */
 440
 441   void (*legacy_read_symtab) (legacy_psymtab *, struct objfile *) = nullptr;
 442
 443   /* Pointer to function which will actually expand this psymtab into
 444      a full symtab.  */
 445
 446   void (*legacy_expand_psymtab) (legacy_psymtab *, struct objfile *) = nullptr;
 447
 448   /* Information that lets read_symtab() locate the part of the symbol table
 449      that this psymtab corresponds to.  This information is private to the
 450      format-dependent symbol reading routines.  For further detail examine
 451      the various symbol reading modules.  */
 452
 453   void *read_symtab_private = nullptr;
 454 };
 455
 456 /* Used when recording partial symbol tables.  On destruction,
 457    discards any partial symbol tables that have been built.  However,
 458    the tables can be kept by calling the "keep" method.  */
 459 class psymtab_discarder
 460 {
 461  public:
 462
 463   psymtab_discarder (psymtab_storage *partial_symtabs)
 464     : m_partial_symtabs (partial_symtabs),
 465       m_psymtab (partial_symtabs->psymtabs)
 466   {
 467   }
 468
 469   ~psymtab_discarder ()
 470   {
 471     if (m_partial_symtabs != nullptr)
 472       m_partial_symtabs->discard_psymtabs_to (m_psymtab);
 473   }
 474
 475   /* Keep any partial symbol tables that were built.  */
 476   void keep ()
 477   {
 478     m_partial_symtabs = nullptr;
 479   }
 480
 481  private:
 482
 483   /* The partial symbol storage object.  */
 484   psymtab_storage *m_partial_symtabs;
 485   /* How far back to free.  */
 486   struct partial_symtab *m_psymtab;
 487 };
 488
 489 /* An implementation of quick_symbol_functions, specialized for
 490    partial symbols.  */
 491 struct psymbol_functions : public quick_symbol_functions
 492 {
 493   explicit psymbol_functions (const std::shared_ptr<psymtab_storage> &storage)
 494     : m_partial_symtabs (storage)
 495   {
 496   }
 497
 498   psymbol_functions ()
 499     : m_partial_symtabs (new psymtab_storage)
 500   {
 501   }
 502
 503   bool has_symbols (struct objfile *objfile) override;
 504
 505   struct symtab *find_last_source_symtab (struct objfile *objfile) override;
 506
 507   void forget_cached_source_info (struct objfile *objfile) override;
 508
 509   bool map_symtabs_matching_filename
 510     (struct objfile *objfile, const char *name, const char *real_path,
 511      gdb::function_view<bool (symtab *)> callback) override;
 512
 513   struct compunit_symtab *lookup_symbol (struct objfile *objfile,
 514                                          block_enum block_index,
 515                                          const char *name,
 516                                          domain_enum domain) override;
 517
 518   enum language lookup_global_symbol_language (struct objfile *objfile,
 519                                                const char *name,
 520                                                domain_enum domain,
 521                                                bool *symbol_found_p) override;
 522
 523   void print_stats (struct objfile *objfile, bool print_bcache) override;
 524
 525   void dump (struct objfile *objfile) override;
 526
 527   void expand_symtabs_for_function (struct objfile *objfile,
 528                                     const char *func_name) override;
 529
 530   void expand_all_symtabs (struct objfile *objfile) override;
 531
 532   void expand_symtabs_with_fullname (struct objfile *objfile,
 533                                      const char *fullname) override;
 534
 535   void map_matching_symbols
 536     (struct objfile *,
 537      const lookup_name_info &lookup_name,
 538      domain_enum domain,
 539      int global,
 540      gdb::function_view<symbol_found_callback_ftype> callback,
 541      symbol_compare_ftype *ordered_compare) override;
 542
 543   void expand_symtabs_matching
 544     (struct objfile *objfile,
 545      gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher,
 546      const lookup_name_info *lookup_name,
 547      gdb::function_view<expand_symtabs_symbol_matcher_ftype> symbol_matcher,
 548      gdb::function_view<expand_symtabs_exp_notify_ftype> expansion_notify,
 549      enum search_domain kind) override;
 550
 551   struct compunit_symtab *find_pc_sect_compunit_symtab
 552     (struct objfile *objfile, struct bound_minimal_symbol msymbol,
 553      CORE_ADDR pc, struct obj_section *section, int warn_if_readin) override;
 554
 555   struct compunit_symtab *find_compunit_symtab_by_address
 556     (struct objfile *objfile, CORE_ADDR address) override;
 557
 558   void map_symbol_filenames (struct objfile *objfile,
 559                              symbol_filename_ftype *fun, void *data,
 560                              int need_fullname) override;
 561
 562   void relocated () override
 563   {
 564     m_psymbol_map.clear ();
 565   }
 566
 567   /* Ensure the partial symbols for OBJFILE have been loaded.  Return
 568      a range adapter for the psymtabs.  */
 569   psymtab_storage::partial_symtab_range require_partial_symbols
 570        (struct objfile *objfile);
 571
 572   /* Return the partial symbol storage associated with this
 573      object.  */
 574   const std::shared_ptr<psymtab_storage> &get_partial_symtabs () const
 575   {
 576     return m_partial_symtabs;
 577   }
 578
 579   /* Replace the partial symbol table storage in this object with
 580      SYMS.  */
 581   void set_partial_symtabs (const std::shared_ptr<psymtab_storage> &syms)
 582   {
 583     m_partial_symtabs = syms;
 584   }
 585
 586   /* Find which partial symtab contains PC and SECTION.  Return NULL if
 587      none.  We return the psymtab that contains a symbol whose address
 588      exactly matches PC, or, if we cannot find an exact match, the
 589      psymtab that contains a symbol whose address is closest to PC.  */
 590
 591   struct partial_symtab *find_pc_sect_psymtab
 592        (struct objfile *objfile,
 593         CORE_ADDR pc,
 594         struct obj_section *section,
 595         struct bound_minimal_symbol msymbol);
 596
 597 private:
 598
 599   /* Count the number of partial symbols in *THIS.  */
 600   int count_psyms ();
 601
 602   void fill_psymbol_map (struct objfile *objfile,
 603                          struct partial_symtab *psymtab,
 604                          std::set<CORE_ADDR> *seen_addrs,
 605                          const std::vector<partial_symbol *> &symbols);
 606
 607   /* Storage for the partial symbols.  */
 608   std::shared_ptr<psymtab_storage> m_partial_symtabs;
 609
 610   /* Map symbol addresses to the partial symtab that defines the
 611      object at that address.  */
 612
 613   std::vector<std::pair<CORE_ADDR, partial_symtab *>> m_psymbol_map;
 614 };
 615
 616 #endif /* PSYMPRIV_H */