/* Block-related functions for the GNU debugger, GDB. Copyright (C) 2003-2014 Free Software Foundation, Inc. This file is part of GDB. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ #include "defs.h" #include "block.h" #include "symtab.h" #include "symfile.h" #include "gdb_obstack.h" #include "cp-support.h" #include "addrmap.h" #include "gdbtypes.h" /* This is used by struct block to store namespace-related info for C++ files, namely using declarations and the current namespace in scope. */ struct block_namespace_info { const char *scope; struct using_direct *using; }; static void block_initialize_namespace (struct block *block, struct obstack *obstack); /* Return Nonzero if block a is lexically nested within block b, or if a and b have the same pc range. Return zero otherwise. */ int contained_in (const struct block *a, const struct block *b) { if (!a || !b) return 0; do { if (a == b) return 1; /* If A is a function block, then A cannot be contained in B, except if A was inlined. */ if (BLOCK_FUNCTION (a) != NULL && !block_inlined_p (a)) return 0; a = BLOCK_SUPERBLOCK (a); } while (a != NULL); return 0; } /* Return the symbol for the function which contains a specified lexical block, described by a struct block BL. The return value will not be an inlined function; the containing function will be returned instead. */ struct symbol * block_linkage_function (const struct block *bl) { while ((BLOCK_FUNCTION (bl) == NULL || block_inlined_p (bl)) && BLOCK_SUPERBLOCK (bl) != NULL) bl = BLOCK_SUPERBLOCK (bl); return BLOCK_FUNCTION (bl); } /* Return the symbol for the function which contains a specified block, described by a struct block BL. The return value will be the closest enclosing function, which might be an inline function. */ struct symbol * block_containing_function (const struct block *bl) { while (BLOCK_FUNCTION (bl) == NULL && BLOCK_SUPERBLOCK (bl) != NULL) bl = BLOCK_SUPERBLOCK (bl); return BLOCK_FUNCTION (bl); } /* Return one if BL represents an inlined function. */ int block_inlined_p (const struct block *bl) { return BLOCK_FUNCTION (bl) != NULL && SYMBOL_INLINED (BLOCK_FUNCTION (bl)); } /* A helper function that checks whether PC is in the blockvector BL. It returns the containing block if there is one, or else NULL. */ static struct block * find_block_in_blockvector (const struct blockvector *bl, CORE_ADDR pc) { struct block *b; int bot, top, half; /* If we have an addrmap mapping code addresses to blocks, then use that. */ if (BLOCKVECTOR_MAP (bl)) return addrmap_find (BLOCKVECTOR_MAP (bl), pc); /* Otherwise, use binary search to find the last block that starts before PC. Note: GLOBAL_BLOCK is block 0, STATIC_BLOCK is block 1. They both have the same START,END values. Historically this code would choose STATIC_BLOCK over GLOBAL_BLOCK but the fact that this choice was made was subtle, now we make it explicit. */ gdb_assert (BLOCKVECTOR_NBLOCKS (bl) >= 2); bot = STATIC_BLOCK; top = BLOCKVECTOR_NBLOCKS (bl); while (top - bot > 1) { half = (top - bot + 1) >> 1; b = BLOCKVECTOR_BLOCK (bl, bot + half); if (BLOCK_START (b) <= pc) bot += half; else top = bot + half; } /* Now search backward for a block that ends after PC. */ while (bot >= STATIC_BLOCK) { b = BLOCKVECTOR_BLOCK (bl, bot); if (BLOCK_END (b) > pc) return b; bot--; } return NULL; } /* Return the blockvector immediately containing the innermost lexical block containing the specified pc value and section, or 0 if there is none. PBLOCK is a pointer to the block. If PBLOCK is NULL, we don't pass this information back to the caller. */ const struct blockvector * blockvector_for_pc_sect (CORE_ADDR pc, struct obj_section *section, const struct block **pblock, struct symtab *symtab) { const struct blockvector *bl; struct block *b; if (symtab == 0) /* if no symtab specified by caller */ { /* First search all symtabs for one whose file contains our pc */ symtab = find_pc_sect_symtab (pc, section); if (symtab == 0) return 0; } bl = BLOCKVECTOR (symtab); /* Then search that symtab for the smallest block that wins. */ b = find_block_in_blockvector (bl, pc); if (b == NULL) return NULL; if (pblock) *pblock = b; return bl; } /* Return true if the blockvector BV contains PC, false otherwise. */ int blockvector_contains_pc (const struct blockvector *bv, CORE_ADDR pc) { return find_block_in_blockvector (bv, pc) != NULL; } /* Return call_site for specified PC in GDBARCH. PC must match exactly, it must be the next instruction after call (or after tail call jump). Throw NO_ENTRY_VALUE_ERROR otherwise. This function never returns NULL. */ struct call_site * call_site_for_pc (struct gdbarch *gdbarch, CORE_ADDR pc) { struct symtab *symtab; void **slot = NULL; /* -1 as tail call PC can be already after the compilation unit range. */ symtab = find_pc_symtab (pc - 1); if (symtab != NULL && symtab->call_site_htab != NULL) slot = htab_find_slot (symtab->call_site_htab, &pc, NO_INSERT); if (slot == NULL) { struct bound_minimal_symbol msym = lookup_minimal_symbol_by_pc (pc); /* DW_TAG_gnu_call_site will be missing just if GCC could not determine the call target. */ throw_error (NO_ENTRY_VALUE_ERROR, _("DW_OP_GNU_entry_value resolving cannot find " "DW_TAG_GNU_call_site %s in %s"), paddress (gdbarch, pc), (msym.minsym == NULL ? "???" : MSYMBOL_PRINT_NAME (msym.minsym))); } return *slot; } /* Return the blockvector immediately containing the innermost lexical block containing the specified pc value, or 0 if there is none. Backward compatibility, no section. */ const struct blockvector * blockvector_for_pc (CORE_ADDR pc, const struct block **pblock) { return blockvector_for_pc_sect (pc, find_pc_mapped_section (pc), pblock, NULL); } /* Return the innermost lexical block containing the specified pc value in the specified section, or 0 if there is none. */ const struct block * block_for_pc_sect (CORE_ADDR pc, struct obj_section *section) { const struct blockvector *bl; const struct block *b; bl = blockvector_for_pc_sect (pc, section, &b, NULL); if (bl) return b; return 0; } /* Return the innermost lexical block containing the specified pc value, or 0 if there is none. Backward compatibility, no section. */ const struct block * block_for_pc (CORE_ADDR pc) { return block_for_pc_sect (pc, find_pc_mapped_section (pc)); } /* Now come some functions designed to deal with C++ namespace issues. The accessors are safe to use even in the non-C++ case. */ /* This returns the namespace that BLOCK is enclosed in, or "" if it isn't enclosed in a namespace at all. This travels the chain of superblocks looking for a scope, if necessary. */ const char * block_scope (const struct block *block) { for (; block != NULL; block = BLOCK_SUPERBLOCK (block)) { if (BLOCK_NAMESPACE (block) != NULL && BLOCK_NAMESPACE (block)->scope != NULL) return BLOCK_NAMESPACE (block)->scope; } return ""; } /* Set BLOCK's scope member to SCOPE; if needed, allocate memory via OBSTACK. (It won't make a copy of SCOPE, however, so that already has to be allocated correctly.) */ void block_set_scope (struct block *block, const char *scope, struct obstack *obstack) { block_initialize_namespace (block, obstack); BLOCK_NAMESPACE (block)->scope = scope; } /* This returns the using directives list associated with BLOCK, if any. */ struct using_direct * block_using (const struct block *block) { if (block == NULL || BLOCK_NAMESPACE (block) == NULL) return NULL; else return BLOCK_NAMESPACE (block)->using; } /* Set BLOCK's using member to USING; if needed, allocate memory via OBSTACK. (It won't make a copy of USING, however, so that already has to be allocated correctly.) */ void block_set_using (struct block *block, struct using_direct *using, struct obstack *obstack) { block_initialize_namespace (block, obstack); BLOCK_NAMESPACE (block)->using = using; } /* If BLOCK_NAMESPACE (block) is NULL, allocate it via OBSTACK and ititialize its members to zero. */ static void block_initialize_namespace (struct block *block, struct obstack *obstack) { if (BLOCK_NAMESPACE (block) == NULL) { BLOCK_NAMESPACE (block) = obstack_alloc (obstack, sizeof (struct block_namespace_info)); BLOCK_NAMESPACE (block)->scope = NULL; BLOCK_NAMESPACE (block)->using = NULL; } } /* Return the static block associated to BLOCK. Return NULL if block is NULL or if block is a global block. */ const struct block * block_static_block (const struct block *block) { if (block == NULL || BLOCK_SUPERBLOCK (block) == NULL) return NULL; while (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) != NULL) block = BLOCK_SUPERBLOCK (block); return block; } /* Return the static block associated to BLOCK. Return NULL if block is NULL. */ const struct block * block_global_block (const struct block *block) { if (block == NULL) return NULL; while (BLOCK_SUPERBLOCK (block) != NULL) block = BLOCK_SUPERBLOCK (block); return block; } /* Allocate a block on OBSTACK, and initialize its elements to zero/NULL. This is useful for creating "dummy" blocks that don't correspond to actual source files. Warning: it sets the block's BLOCK_DICT to NULL, which isn't a valid value. If you really don't want the block to have a dictionary, then you should subsequently set its BLOCK_DICT to dict_create_linear (obstack, NULL). */ struct block * allocate_block (struct obstack *obstack) { struct block *bl = OBSTACK_ZALLOC (obstack, struct block); return bl; } /* Allocate a global block. */ struct block * allocate_global_block (struct obstack *obstack) { struct global_block *bl = OBSTACK_ZALLOC (obstack, struct global_block); return &bl->block; } /* Set the symtab of the global block. */ void set_block_symtab (struct block *block, struct symtab *symtab) { struct global_block *gb; gdb_assert (BLOCK_SUPERBLOCK (block) == NULL); gb = (struct global_block *) block; gdb_assert (gb->symtab == NULL); gb->symtab = symtab; } /* Return the symtab of the global block. */ static struct symtab * get_block_symtab (const struct block *block) { struct global_block *gb; gdb_assert (BLOCK_SUPERBLOCK (block) == NULL); gb = (struct global_block *) block; gdb_assert (gb->symtab != NULL); return gb->symtab; } /* Initialize a block iterator, either to iterate over a single block, or, for static and global blocks, all the included symtabs as well. */ static void initialize_block_iterator (const struct block *block, struct block_iterator *iter) { enum block_enum which; struct symtab *symtab; iter->idx = -1; if (BLOCK_SUPERBLOCK (block) == NULL) { which = GLOBAL_BLOCK; symtab = get_block_symtab (block); } else if (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL) { which = STATIC_BLOCK; symtab = get_block_symtab (BLOCK_SUPERBLOCK (block)); } else { iter->d.block = block; /* A signal value meaning that we're iterating over a single block. */ iter->which = FIRST_LOCAL_BLOCK; return; } /* If this is an included symtab, find the canonical includer and use it instead. */ while (symtab->user != NULL) symtab = symtab->user; /* Putting this check here simplifies the logic of the iterator functions. If there are no included symtabs, we only need to search a single block, so we might as well just do that directly. */ if (symtab->includes == NULL) { iter->d.block = block; /* A signal value meaning that we're iterating over a single block. */ iter->which = FIRST_LOCAL_BLOCK; } else { iter->d.symtab = symtab; iter->which = which; } } /* A helper function that finds the current symtab over whose static or global block we should iterate. */ static struct symtab * find_iterator_symtab (struct block_iterator *iterator) { if (iterator->idx == -1) return iterator->d.symtab; return iterator->d.symtab->includes[iterator->idx]; } /* Perform a single step for a plain block iterator, iterating across symbol tables as needed. Returns the next symbol, or NULL when iteration is complete. */ static struct symbol * block_iterator_step (struct block_iterator *iterator, int first) { struct symbol *sym; gdb_assert (iterator->which != FIRST_LOCAL_BLOCK); while (1) { if (first) { struct symtab *symtab = find_iterator_symtab (iterator); const struct block *block; /* Iteration is complete. */ if (symtab == NULL) return NULL; block = BLOCKVECTOR_BLOCK (BLOCKVECTOR (symtab), iterator->which); sym = dict_iterator_first (BLOCK_DICT (block), &iterator->dict_iter); } else sym = dict_iterator_next (&iterator->dict_iter); if (sym != NULL) return sym; /* We have finished iterating the appropriate block of one symtab. Now advance to the next symtab and begin iteration there. */ ++iterator->idx; first = 1; } } /* See block.h. */ struct symbol * block_iterator_first (const struct block *block, struct block_iterator *iterator) { initialize_block_iterator (block, iterator); if (iterator->which == FIRST_LOCAL_BLOCK) return dict_iterator_first (block->dict, &iterator->dict_iter); return block_iterator_step (iterator, 1); } /* See block.h. */ struct symbol * block_iterator_next (struct block_iterator *iterator) { if (iterator->which == FIRST_LOCAL_BLOCK) return dict_iterator_next (&iterator->dict_iter); return block_iterator_step (iterator, 0); } /* Perform a single step for a "name" block iterator, iterating across symbol tables as needed. Returns the next symbol, or NULL when iteration is complete. */ static struct symbol * block_iter_name_step (struct block_iterator *iterator, const char *name, int first) { struct symbol *sym; gdb_assert (iterator->which != FIRST_LOCAL_BLOCK); while (1) { if (first) { struct symtab *symtab = find_iterator_symtab (iterator); const struct block *block; /* Iteration is complete. */ if (symtab == NULL) return NULL; block = BLOCKVECTOR_BLOCK (BLOCKVECTOR (symtab), iterator->which); sym = dict_iter_name_first (BLOCK_DICT (block), name, &iterator->dict_iter); } else sym = dict_iter_name_next (name, &iterator->dict_iter); if (sym != NULL) return sym; /* We have finished iterating the appropriate block of one symtab. Now advance to the next symtab and begin iteration there. */ ++iterator->idx; first = 1; } } /* See block.h. */ struct symbol * block_iter_name_first (const struct block *block, const char *name, struct block_iterator *iterator) { initialize_block_iterator (block, iterator); if (iterator->which == FIRST_LOCAL_BLOCK) return dict_iter_name_first (block->dict, name, &iterator->dict_iter); return block_iter_name_step (iterator, name, 1); } /* See block.h. */ struct symbol * block_iter_name_next (const char *name, struct block_iterator *iterator) { if (iterator->which == FIRST_LOCAL_BLOCK) return dict_iter_name_next (name, &iterator->dict_iter); return block_iter_name_step (iterator, name, 0); } /* Perform a single step for a "match" block iterator, iterating across symbol tables as needed. Returns the next symbol, or NULL when iteration is complete. */ static struct symbol * block_iter_match_step (struct block_iterator *iterator, const char *name, symbol_compare_ftype *compare, int first) { struct symbol *sym; gdb_assert (iterator->which != FIRST_LOCAL_BLOCK); while (1) { if (first) { struct symtab *symtab = find_iterator_symtab (iterator); const struct block *block; /* Iteration is complete. */ if (symtab == NULL) return NULL; block = BLOCKVECTOR_BLOCK (BLOCKVECTOR (symtab), iterator->which); sym = dict_iter_match_first (BLOCK_DICT (block), name, compare, &iterator->dict_iter); } else sym = dict_iter_match_next (name, compare, &iterator->dict_iter); if (sym != NULL) return sym; /* We have finished iterating the appropriate block of one symtab. Now advance to the next symtab and begin iteration there. */ ++iterator->idx; first = 1; } } /* See block.h. */ struct symbol * block_iter_match_first (const struct block *block, const char *name, symbol_compare_ftype *compare, struct block_iterator *iterator) { initialize_block_iterator (block, iterator); if (iterator->which == FIRST_LOCAL_BLOCK) return dict_iter_match_first (block->dict, name, compare, &iterator->dict_iter); return block_iter_match_step (iterator, name, compare, 1); } /* See block.h. */ struct symbol * block_iter_match_next (const char *name, symbol_compare_ftype *compare, struct block_iterator *iterator) { if (iterator->which == FIRST_LOCAL_BLOCK) return dict_iter_match_next (name, compare, &iterator->dict_iter); return block_iter_match_step (iterator, name, compare, 0); } /* See block.h. Note that if NAME is the demangled form of a C++ symbol, we will fail to find a match during the binary search of the non-encoded names, but for now we don't worry about the slight inefficiency of looking for a match we'll never find, since it will go pretty quick. Once the binary search terminates, we drop through and do a straight linear search on the symbols. Each symbol which is marked as being a ObjC/C++ symbol (language_cplus or language_objc set) has both the encoded and non-encoded names tested for a match. */ struct symbol * block_lookup_symbol (const struct block *block, const char *name, const domain_enum domain) { struct block_iterator iter; struct symbol *sym; if (!BLOCK_FUNCTION (block)) { for (sym = block_iter_name_first (block, name, &iter); sym != NULL; sym = block_iter_name_next (name, &iter)) { if (symbol_matches_domain (SYMBOL_LANGUAGE (sym), SYMBOL_DOMAIN (sym), domain)) return sym; } return NULL; } else { /* Note that parameter symbols do not always show up last in the list; this loop makes sure to take anything else other than parameter symbols first; it only uses parameter symbols as a last resort. Note that this only takes up extra computation time on a match. */ struct symbol *sym_found = NULL; for (sym = block_iter_name_first (block, name, &iter); sym != NULL; sym = block_iter_name_next (name, &iter)) { if (symbol_matches_domain (SYMBOL_LANGUAGE (sym), SYMBOL_DOMAIN (sym), domain)) { sym_found = sym; if (!SYMBOL_IS_ARGUMENT (sym)) { break; } } } return (sym_found); /* Will be NULL if not found. */ } }