gdb/block.h

   1 /* Code dealing with blocks for GDB.
   2
   3    Copyright 2003 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 2 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, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #ifndef BLOCK_H
  23 #define BLOCK_H
  24
  25 /* Opaque declarations.  */
  26
  27 struct symbol;
  28 struct symtab;
  29 struct block_namespace_info;
  30 struct using_direct;
  31 struct obstack;
  32
  33 /* All of the name-scope contours of the program
  34    are represented by `struct block' objects.
  35    All of these objects are pointed to by the blockvector.
  36
  37    Each block represents one name scope.
  38    Each lexical context has its own block.
  39
  40    The blockvector begins with some special blocks.
  41    The GLOBAL_BLOCK contains all the symbols defined in this compilation
  42    whose scope is the entire program linked together.
  43    The STATIC_BLOCK contains all the symbols whose scope is the
  44    entire compilation excluding other separate compilations.
  45    Blocks starting with the FIRST_LOCAL_BLOCK are not special.
  46
  47    Each block records a range of core addresses for the code that
  48    is in the scope of the block.  The STATIC_BLOCK and GLOBAL_BLOCK
  49    give, for the range of code, the entire range of code produced
  50    by the compilation that the symbol segment belongs to.
  51
  52    The blocks appear in the blockvector
  53    in order of increasing starting-address,
  54    and, within that, in order of decreasing ending-address.
  55
  56    This implies that within the body of one function
  57    the blocks appear in the order of a depth-first tree walk.  */
  58
  59 struct block
  60 {
  61
  62   /* Addresses in the executable code that are in this block.  */
  63
  64   CORE_ADDR startaddr;
  65   CORE_ADDR endaddr;
  66
  67   /* The symbol that names this block, if the block is the body of a
  68      function; otherwise, zero.  */
  69
  70   struct symbol *function;
  71
  72   /* The `struct block' for the containing block, or 0 if none.
  73
  74      The superblock of a top-level local block (i.e. a function in the
  75      case of C) is the STATIC_BLOCK.  The superblock of the
  76      STATIC_BLOCK is the GLOBAL_BLOCK.  */
  77
  78   struct block *superblock;
  79
  80   /* Used for language-specific info.  */
  81
  82   union
  83   {
  84     struct
  85     {
  86       /* Contains information about namespace-related info relevant to
  87          this block: using directives and the current namespace
  88          scope.  */
  89
  90       struct block_namespace_info *namespace;
  91     }
  92     cplus_specific;
  93   }
  94   language_specific;
  95
  96   /* Version of GCC used to compile the function corresponding
  97      to this block, or 0 if not compiled with GCC.  When possible,
  98      GCC should be compatible with the native compiler, or if that
  99      is not feasible, the differences should be fixed during symbol
 100      reading.  As of 16 Apr 93, this flag is never used to distinguish
 101      between gcc2 and the native compiler.
 102
 103      If there is no function corresponding to this block, this meaning
 104      of this flag is undefined.  */
 105
 106   unsigned char gcc_compile_flag;
 107
 108   /* The symbols for this block are either in a simple linear list or
 109      in a simple hashtable.  Blocks which correspond to a function
 110      (which have a list of symbols corresponding to arguments) use
 111      a linear list, as do some older symbol readers (currently only
 112      mdebugread and dstread).  Other blocks are hashed.
 113
 114      The hashtable uses the same hash function as the minsym hashtables,
 115      found in minsyms.c:minsym_hash_iw.  Symbols are hashed based on
 116      their demangled name if appropriate, and on their name otherwise.
 117      The hash function ignores space, and stops at the beginning of the
 118      argument list if any.
 119
 120      The table is laid out in NSYMS/5 buckets and symbols are chained via
 121      their hash_next field.  */
 122
 123   /* If this is really a hashtable of the symbols, this flag is 1.  */
 124
 125   unsigned char hashtable;
 126
 127   /* Number of local symbols.  */
 128
 129   int nsyms;
 130
 131   /* The symbols.  If some of them are arguments, then they must be
 132      in the order in which we would like to print them.  */
 133
 134   struct symbol *sym[1];
 135 };
 136
 137 #define BLOCK_START(bl)         (bl)->startaddr
 138 #define BLOCK_END(bl)           (bl)->endaddr
 139 #define BLOCK_FUNCTION(bl)      (bl)->function
 140 #define BLOCK_SUPERBLOCK(bl)    (bl)->superblock
 141 #define BLOCK_GCC_COMPILED(bl)  (bl)->gcc_compile_flag
 142 #define BLOCK_NAMESPACE(bl)   (bl)->language_specific.cplus_specific.namespace
 143 #define BLOCK_HASHTABLE(bl)     (bl)->hashtable
 144
 145 /* For blocks without a hashtable (BLOCK_HASHTABLE (bl) == 0) only.  */
 146 #define BLOCK_NSYMS(bl)         (bl)->nsyms
 147 #define BLOCK_SYM(bl, n)        (bl)->sym[n]
 148
 149 /* For blocks with a hashtable, but these are valid for non-hashed blocks as
 150    well - each symbol will appear to be one bucket by itself.  */
 151 #define BLOCK_BUCKETS(bl)       (bl)->nsyms
 152 #define BLOCK_BUCKET(bl, n)     (bl)->sym[n]
 153
 154 /* Macro used to set the size of a hashtable for N symbols.  */
 155 #define BLOCK_HASHTABLE_SIZE(n) ((n)/5 + 1)
 156
 157 /* Macro to loop through all symbols in a block BL, in no particular order.
 158    i counts which bucket we are in, and sym points to the current symbol.  */
 159
 160 #define ALL_BLOCK_SYMBOLS(bl, i, sym)                           \
 161         for ((i) = 0; (i) < BLOCK_BUCKETS ((bl)); (i)++)        \
 162           for ((sym) = BLOCK_BUCKET ((bl), (i)); (sym);         \
 163                (sym) = (sym)->hash_next)
 164
 165 /* Nonzero if symbols of block BL should be sorted alphabetically.
 166    Don't sort a block which corresponds to a function.  If we did the
 167    sorting would have to preserve the order of the symbols for the
 168    arguments.  Also don't sort any block that we chose to hash.  */
 169
 170 #define BLOCK_SHOULD_SORT(bl) (! BLOCK_HASHTABLE (bl) \
 171                                && BLOCK_FUNCTION (bl) == NULL)
 172
 173 struct blockvector
 174 {
 175   /* Number of blocks in the list.  */
 176   int nblocks;
 177   /* The blocks themselves.  */
 178   struct block *block[1];
 179 };
 180
 181 #define BLOCKVECTOR_NBLOCKS(blocklist) (blocklist)->nblocks
 182 #define BLOCKVECTOR_BLOCK(blocklist,n) (blocklist)->block[n]
 183
 184 /* Special block numbers */
 185
 186 #define GLOBAL_BLOCK            0
 187 #define STATIC_BLOCK            1
 188 #define FIRST_LOCAL_BLOCK       2
 189
 190 extern struct symbol *block_function (struct block *);
 191
 192 extern int contained_in (struct block *, struct block *);
 193
 194 extern struct blockvector *blockvector_for_pc (CORE_ADDR, int *);
 195
 196 extern struct blockvector *blockvector_for_pc_sect (CORE_ADDR, asection *,
 197                                                     int *, struct symtab *);
 198
 199 extern struct block *block_for_pc (CORE_ADDR);
 200
 201 extern struct block *block_for_pc_sect (CORE_ADDR, asection *);
 202
 203 extern void block_set_scope (struct block *block, const char *scope,
 204                              struct obstack *obstack);
 205
 206 extern void block_set_using (struct block *block,
 207                              struct using_direct *using,
 208                              struct obstack *obstack);
 209
 210 extern const struct block *block_static_block (const struct block *block);
 211
 212 #endif /* BLOCK_H */