1 /* Public partial symbol table definitions. 2 3 Copyright (C) 2009-2020 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 PSYMTAB_H 21 #define PSYMTAB_H 22 23 #include "gdb_obstack.h" 24 #include "symfile.h" 25 #include "gdbsupport/next-iterator.h" 26 #include "bcache.h" 27 28 struct partial_symbol; 29 30 /* An instance of this class manages the partial symbol tables and 31 partial symbols for a given objfile. 32 33 The core psymtab functions -- those in psymtab.c -- arrange for 34 nearly all psymtab- and psymbol-related allocations to happen 35 either in the psymtab_storage object (either on its obstack or in 36 other memory managed by this class), or on the per-BFD object. The 37 only link from the psymtab storage object back to the objfile (or 38 objfile_obstack) that is made by the core psymtab code is the 39 compunit_symtab member in the standard_psymtab -- and a given 40 symbol reader can avoid this by implementing its own subclasses of 41 partial_symtab. 42 43 However, it is up to each symbol reader to maintain this invariant 44 in other ways, if it wants to reuse psymtabs across multiple 45 objfiles. The main issue here is ensuring that read_symtab_private 46 does not point into objfile_obstack. */ 47 48 class psymtab_storage 49 { 50 public: 51 52 psymtab_storage (); 53 54 ~psymtab_storage (); 55 56 DISABLE_COPY_AND_ASSIGN (psymtab_storage); 57 58 /* Discard all partial symbol tables starting with "psymtabs" and 59 proceeding until "to" has been discarded. */ 60 61 void discard_psymtabs_to (struct partial_symtab *to) 62 { 63 while (psymtabs != to) 64 discard_psymtab (psymtabs); 65 } 66 67 /* Discard the partial symbol table. */ 68 69 void discard_psymtab (struct partial_symtab *pst); 70 71 /* Return the obstack that is used for storage by this object. */ 72 73 struct obstack *obstack () 74 { 75 if (!m_obstack.has_value ()) 76 m_obstack.emplace (); 77 return &*m_obstack; 78 } 79 80 /* Allocate storage for the "dependencies" field of a psymtab. 81 NUMBER says how many dependencies there are. */ 82 83 struct partial_symtab **allocate_dependencies (int number) 84 { 85 return OBSTACK_CALLOC (obstack (), number, struct partial_symtab *); 86 } 87 88 /* Install a psymtab on the psymtab list. This transfers ownership 89 of PST to this object. */ 90 91 void install_psymtab (partial_symtab *pst); 92 93 typedef next_adapter<struct partial_symtab> partial_symtab_range; 94 95 /* A range adapter that makes it possible to iterate over all 96 psymtabs in one objfile. */ 97 98 partial_symtab_range range () 99 { 100 return partial_symtab_range (psymtabs); 101 } 102 103 104 /* Each objfile points to a linked list of partial symtabs derived from 105 this file, one partial symtab structure for each compilation unit 106 (source file). */ 107 108 struct partial_symtab *psymtabs = nullptr; 109 110 /* Map addresses to the entries of PSYMTABS. It would be more efficient to 111 have a map per the whole process but ADDRMAP cannot selectively remove 112 its items during FREE_OBJFILE. This mapping is already present even for 113 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. 114 115 The DWARF parser reuses this addrmap to store things other than 116 psymtabs in the cases where debug information is being read from, for 117 example, the .debug-names section. */ 118 119 struct addrmap *psymtabs_addrmap = nullptr; 120 121 /* A byte cache where we can stash arbitrary "chunks" of bytes that 122 will not change. */ 123 124 gdb::bcache psymbol_cache; 125 126 /* Vectors of all partial symbols read in from file. The actual data 127 is stored in the objfile_obstack. */ 128 129 std::vector<partial_symbol *> global_psymbols; 130 std::vector<partial_symbol *> static_psymbols; 131 132 /* Stack of vectors of partial symbols, using during psymtab 133 initialization. */ 134 135 std::vector<std::vector<partial_symbol *>*> current_global_psymbols; 136 std::vector<std::vector<partial_symbol *>*> current_static_psymbols; 137 138 private: 139 140 /* The obstack where allocations are made. This is lazily allocated 141 so that we don't waste memory when there are no psymtabs. */ 142 143 gdb::optional<auto_obstack> m_obstack; 144 }; 145 146 147 extern const struct quick_symbol_functions psym_functions; 148 149 extern const struct quick_symbol_functions dwarf2_gdb_index_functions; 150 extern const struct quick_symbol_functions dwarf2_debug_names_functions; 151 152 /* Ensure that the partial symbols for OBJFILE have been loaded. If 153 VERBOSE is true, then this will print a message when symbols 154 are loaded. This function returns a range adapter suitable for 155 iterating over the psymtabs of OBJFILE. */ 156 157 extern psymtab_storage::partial_symtab_range require_partial_symbols 158 (struct objfile *objfile, bool verbose); 159 160 #endif /* PSYMTAB_H */ 161