1 /* Block-related functions for the GNU debugger, GDB. 2 3 Copyright (C) 2003, 2007, 2008, 2009 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 #include "defs.h" 21 #include "block.h" 22 #include "symtab.h" 23 #include "symfile.h" 24 #include "gdb_obstack.h" 25 #include "cp-support.h" 26 #include "addrmap.h" 27 28 /* This is used by struct block to store namespace-related info for 29 C++ files, namely using declarations and the current namespace in 30 scope. */ 31 32 struct block_namespace_info 33 { 34 const char *scope; 35 struct using_direct *using; 36 }; 37 38 static void block_initialize_namespace (struct block *block, 39 struct obstack *obstack); 40 41 /* Return Nonzero if block a is lexically nested within block b, 42 or if a and b have the same pc range. 43 Return zero otherwise. */ 44 45 int 46 contained_in (const struct block *a, const struct block *b) 47 { 48 if (!a || !b) 49 return 0; 50 51 do 52 { 53 if (a == b) 54 return 1; 55 /* If A is a function block, then A cannot be contained in B, 56 except if A was inlined. */ 57 if (BLOCK_FUNCTION (a) != NULL && !block_inlined_p (a)) 58 return 0; 59 a = BLOCK_SUPERBLOCK (a); 60 } 61 while (a != NULL); 62 63 return 0; 64 } 65 66 67 /* Return the symbol for the function which contains a specified 68 lexical block, described by a struct block BL. The return value 69 will not be an inlined function; the containing function will be 70 returned instead. */ 71 72 struct symbol * 73 block_linkage_function (const struct block *bl) 74 { 75 while ((BLOCK_FUNCTION (bl) == NULL || block_inlined_p (bl)) 76 && BLOCK_SUPERBLOCK (bl) != NULL) 77 bl = BLOCK_SUPERBLOCK (bl); 78 79 return BLOCK_FUNCTION (bl); 80 } 81 82 /* Return one if BL represents an inlined function. */ 83 84 int 85 block_inlined_p (const struct block *bl) 86 { 87 return BLOCK_FUNCTION (bl) != NULL && SYMBOL_INLINED (BLOCK_FUNCTION (bl)); 88 } 89 90 /* Return the blockvector immediately containing the innermost lexical 91 block containing the specified pc value and section, or 0 if there 92 is none. PBLOCK is a pointer to the block. If PBLOCK is NULL, we 93 don't pass this information back to the caller. */ 94 95 struct blockvector * 96 blockvector_for_pc_sect (CORE_ADDR pc, struct obj_section *section, 97 struct block **pblock, struct symtab *symtab) 98 { 99 struct block *b; 100 int bot, top, half; 101 struct blockvector *bl; 102 103 if (symtab == 0) /* if no symtab specified by caller */ 104 { 105 /* First search all symtabs for one whose file contains our pc */ 106 symtab = find_pc_sect_symtab (pc, section); 107 if (symtab == 0) 108 return 0; 109 } 110 111 bl = BLOCKVECTOR (symtab); 112 113 /* Then search that symtab for the smallest block that wins. */ 114 115 /* If we have an addrmap mapping code addresses to blocks, then use 116 that. */ 117 if (BLOCKVECTOR_MAP (bl)) 118 { 119 b = addrmap_find (BLOCKVECTOR_MAP (bl), pc); 120 if (b) 121 { 122 if (pblock) 123 *pblock = b; 124 return bl; 125 } 126 else 127 return 0; 128 } 129 130 131 /* Otherwise, use binary search to find the last block that starts 132 before PC. */ 133 bot = 0; 134 top = BLOCKVECTOR_NBLOCKS (bl); 135 136 while (top - bot > 1) 137 { 138 half = (top - bot + 1) >> 1; 139 b = BLOCKVECTOR_BLOCK (bl, bot + half); 140 if (BLOCK_START (b) <= pc) 141 bot += half; 142 else 143 top = bot + half; 144 } 145 146 /* Now search backward for a block that ends after PC. */ 147 148 while (bot >= 0) 149 { 150 b = BLOCKVECTOR_BLOCK (bl, bot); 151 if (BLOCK_END (b) > pc) 152 { 153 if (pblock) 154 *pblock = b; 155 return bl; 156 } 157 bot--; 158 } 159 return 0; 160 } 161 162 /* Return the blockvector immediately containing the innermost lexical block 163 containing the specified pc value, or 0 if there is none. 164 Backward compatibility, no section. */ 165 166 struct blockvector * 167 blockvector_for_pc (CORE_ADDR pc, struct block **pblock) 168 { 169 return blockvector_for_pc_sect (pc, find_pc_mapped_section (pc), 170 pblock, NULL); 171 } 172 173 /* Return the innermost lexical block containing the specified pc value 174 in the specified section, or 0 if there is none. */ 175 176 struct block * 177 block_for_pc_sect (CORE_ADDR pc, struct obj_section *section) 178 { 179 struct blockvector *bl; 180 struct block *b; 181 182 bl = blockvector_for_pc_sect (pc, section, &b, NULL); 183 if (bl) 184 return b; 185 return 0; 186 } 187 188 /* Return the innermost lexical block containing the specified pc value, 189 or 0 if there is none. Backward compatibility, no section. */ 190 191 struct block * 192 block_for_pc (CORE_ADDR pc) 193 { 194 return block_for_pc_sect (pc, find_pc_mapped_section (pc)); 195 } 196 197 /* Now come some functions designed to deal with C++ namespace issues. 198 The accessors are safe to use even in the non-C++ case. */ 199 200 /* This returns the namespace that BLOCK is enclosed in, or "" if it 201 isn't enclosed in a namespace at all. This travels the chain of 202 superblocks looking for a scope, if necessary. */ 203 204 const char * 205 block_scope (const struct block *block) 206 { 207 for (; block != NULL; block = BLOCK_SUPERBLOCK (block)) 208 { 209 if (BLOCK_NAMESPACE (block) != NULL 210 && BLOCK_NAMESPACE (block)->scope != NULL) 211 return BLOCK_NAMESPACE (block)->scope; 212 } 213 214 return ""; 215 } 216 217 /* Set BLOCK's scope member to SCOPE; if needed, allocate memory via 218 OBSTACK. (It won't make a copy of SCOPE, however, so that already 219 has to be allocated correctly.) */ 220 221 void 222 block_set_scope (struct block *block, const char *scope, 223 struct obstack *obstack) 224 { 225 block_initialize_namespace (block, obstack); 226 227 BLOCK_NAMESPACE (block)->scope = scope; 228 } 229 230 /* This returns the using directives list associated with BLOCK, if 231 any. */ 232 233 struct using_direct * 234 block_using (const struct block *block) 235 { 236 if (block == NULL || BLOCK_NAMESPACE (block) == NULL) 237 return NULL; 238 else 239 return BLOCK_NAMESPACE (block)->using; 240 } 241 242 /* Set BLOCK's using member to USING; if needed, allocate memory via 243 OBSTACK. (It won't make a copy of USING, however, so that already 244 has to be allocated correctly.) */ 245 246 void 247 block_set_using (struct block *block, 248 struct using_direct *using, 249 struct obstack *obstack) 250 { 251 block_initialize_namespace (block, obstack); 252 253 BLOCK_NAMESPACE (block)->using = using; 254 } 255 256 /* If BLOCK_NAMESPACE (block) is NULL, allocate it via OBSTACK and 257 ititialize its members to zero. */ 258 259 static void 260 block_initialize_namespace (struct block *block, struct obstack *obstack) 261 { 262 if (BLOCK_NAMESPACE (block) == NULL) 263 { 264 BLOCK_NAMESPACE (block) 265 = obstack_alloc (obstack, sizeof (struct block_namespace_info)); 266 BLOCK_NAMESPACE (block)->scope = NULL; 267 BLOCK_NAMESPACE (block)->using = NULL; 268 } 269 } 270 271 /* Return the static block associated to BLOCK. Return NULL if block 272 is NULL or if block is a global block. */ 273 274 const struct block * 275 block_static_block (const struct block *block) 276 { 277 if (block == NULL || BLOCK_SUPERBLOCK (block) == NULL) 278 return NULL; 279 280 while (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) != NULL) 281 block = BLOCK_SUPERBLOCK (block); 282 283 return block; 284 } 285 286 /* Return the static block associated to BLOCK. Return NULL if block 287 is NULL. */ 288 289 const struct block * 290 block_global_block (const struct block *block) 291 { 292 if (block == NULL) 293 return NULL; 294 295 while (BLOCK_SUPERBLOCK (block) != NULL) 296 block = BLOCK_SUPERBLOCK (block); 297 298 return block; 299 } 300 301 /* Allocate a block on OBSTACK, and initialize its elements to 302 zero/NULL. This is useful for creating "dummy" blocks that don't 303 correspond to actual source files. 304 305 Warning: it sets the block's BLOCK_DICT to NULL, which isn't a 306 valid value. If you really don't want the block to have a 307 dictionary, then you should subsequently set its BLOCK_DICT to 308 dict_create_linear (obstack, NULL). */ 309 310 struct block * 311 allocate_block (struct obstack *obstack) 312 { 313 struct block *bl = obstack_alloc (obstack, sizeof (struct block)); 314 315 BLOCK_START (bl) = 0; 316 BLOCK_END (bl) = 0; 317 BLOCK_FUNCTION (bl) = NULL; 318 BLOCK_SUPERBLOCK (bl) = NULL; 319 BLOCK_DICT (bl) = NULL; 320 BLOCK_NAMESPACE (bl) = NULL; 321 322 return bl; 323 } 324