/* Block-related functions for the GNU debugger, GDB. Copyright (C) 2003-2018 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" #include "objfiles.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_decl; }; static void block_initialize_namespace (struct block *block, struct obstack *obstack); /* See block.h. */ struct objfile * block_objfile (const struct block *block) { const struct global_block *global_block; if (BLOCK_FUNCTION (block) != NULL) return symbol_objfile (BLOCK_FUNCTION (block)); global_block = (struct global_block *) block_global_block (block); return COMPUNIT_OBJFILE (global_block->compunit_symtab); } /* See block. */ struct gdbarch * block_gdbarch (const struct block *block) { if (BLOCK_FUNCTION (block) != NULL) return symbol_arch (BLOCK_FUNCTION (block)); return get_objfile_arch (block_objfile (block)); } /* 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 (struct block *) 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 compunit_symtab *cust) { const struct blockvector *bl; struct block *b; if (cust == NULL) { /* First search all symtabs for one whose file contains our pc */ cust = find_pc_sect_compunit_symtab (pc, section); if (cust == NULL) return 0; } bl = COMPUNIT_BLOCKVECTOR (cust); /* 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 compunit_symtab *cust; void **slot = NULL; /* -1 as tail call PC can be already after the compilation unit range. */ cust = find_pc_compunit_symtab (pc - 1); if (cust != NULL && COMPUNIT_CALL_SITE_HTAB (cust) != NULL) slot = htab_find_slot (COMPUNIT_CALL_SITE_HTAB (cust), &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_entry_value resolving cannot find " "DW_TAG_call_site %s in %s"), paddress (gdbarch, pc), (msym.minsym == NULL ? "???" : MSYMBOL_PRINT_NAME (msym.minsym))); } return (struct call_site *) *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_decl; } /* 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_decl, struct obstack *obstack) { block_initialize_namespace (block, obstack); BLOCK_NAMESPACE (block)->using_decl = using_decl; } /* 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) = XOBNEW (obstack, struct block_namespace_info); BLOCK_NAMESPACE (block)->scope = NULL; BLOCK_NAMESPACE (block)->using_decl = 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 compunit of the global block. */ void set_block_compunit_symtab (struct block *block, struct compunit_symtab *cu) { struct global_block *gb; gdb_assert (BLOCK_SUPERBLOCK (block) == NULL); gb = (struct global_block *) block; gdb_assert (gb->compunit_symtab == NULL); gb->compunit_symtab = cu; } /* See block.h. */ struct dynamic_prop * block_static_link (const struct block *block) { struct objfile *objfile = block_objfile (block); /* Only objfile-owned blocks that materialize top function scopes can have static links. */ if (objfile == NULL || BLOCK_FUNCTION (block) == NULL) return NULL; return (struct dynamic_prop *) objfile_lookup_static_link (objfile, block); } /* Return the compunit of the global block. */ static struct compunit_symtab * get_block_compunit_symtab (const struct block *block) { struct global_block *gb; gdb_assert (BLOCK_SUPERBLOCK (block) == NULL); gb = (struct global_block *) block; gdb_assert (gb->compunit_symtab != NULL); return gb->compunit_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 compunit_symtab *cu; iter->idx = -1; if (BLOCK_SUPERBLOCK (block) == NULL) { which = GLOBAL_BLOCK; cu = get_block_compunit_symtab (block); } else if (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL) { which = STATIC_BLOCK; cu = get_block_compunit_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 (cu->user != NULL) cu = cu->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 (cu->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.compunit_symtab = cu; iter->which = which; } } /* A helper function that finds the current compunit over whose static or global block we should iterate. */ static struct compunit_symtab * find_iterator_compunit_symtab (struct block_iterator *iterator) { if (iterator->idx == -1) return iterator->d.compunit_symtab; return iterator->d.compunit_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 compunit_symtab *cust = find_iterator_compunit_symtab (iterator); const struct block *block; /* Iteration is complete. */ if (cust == NULL) return NULL; block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust), 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 "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 lookup_name_info &name, int first) { struct symbol *sym; gdb_assert (iterator->which != FIRST_LOCAL_BLOCK); while (1) { if (first) { struct compunit_symtab *cust = find_iterator_compunit_symtab (iterator); const struct block *block; /* Iteration is complete. */ if (cust == NULL) return NULL; block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust), iterator->which); sym = dict_iter_match_first (BLOCK_DICT (block), name, &iterator->dict_iter); } else sym = dict_iter_match_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_match_first (const struct block *block, const lookup_name_info &name, struct block_iterator *iterator) { initialize_block_iterator (block, iterator); if (iterator->which == FIRST_LOCAL_BLOCK) return dict_iter_match_first (block->dict, name, &iterator->dict_iter); return block_iter_match_step (iterator, name, 1); } /* See block.h. */ struct symbol * block_iter_match_next (const lookup_name_info &name, struct block_iterator *iterator) { if (iterator->which == FIRST_LOCAL_BLOCK) return dict_iter_match_next (name, &iterator->dict_iter); return block_iter_match_step (iterator, name, 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, symbol_name_match_type match_type, const domain_enum domain) { struct block_iterator iter; struct symbol *sym; lookup_name_info lookup_name (name, match_type); if (!BLOCK_FUNCTION (block)) { struct symbol *other = NULL; ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym) { if (SYMBOL_DOMAIN (sym) == domain) return sym; /* This is a bit of a hack, but symbol_matches_domain might ignore STRUCT vs VAR domain symbols. So if a matching symbol is found, make sure there is no "better" matching symbol, i.e., one with exactly the same domain. PR 16253. */ if (symbol_matches_domain (SYMBOL_LANGUAGE (sym), SYMBOL_DOMAIN (sym), domain)) other = sym; } return other; } 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. It's hard to define types in the parameter list (at least in C/C++) so we don't do the same PR 16253 hack here that is done for the !BLOCK_FUNCTION case. */ struct symbol *sym_found = NULL; ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym) { 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. */ } } /* See block.h. */ struct symbol * block_lookup_symbol_primary (const struct block *block, const char *name, const domain_enum domain) { struct symbol *sym, *other; struct dict_iterator dict_iter; lookup_name_info lookup_name (name, symbol_name_match_type::FULL); /* Verify BLOCK is STATIC_BLOCK or GLOBAL_BLOCK. */ gdb_assert (BLOCK_SUPERBLOCK (block) == NULL || BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL); other = NULL; for (sym = dict_iter_match_first (block->dict, lookup_name, &dict_iter); sym != NULL; sym = dict_iter_match_next (lookup_name, &dict_iter)) { if (SYMBOL_DOMAIN (sym) == domain) return sym; /* This is a bit of a hack, but symbol_matches_domain might ignore STRUCT vs VAR domain symbols. So if a matching symbol is found, make sure there is no "better" matching symbol, i.e., one with exactly the same domain. PR 16253. */ if (symbol_matches_domain (SYMBOL_LANGUAGE (sym), SYMBOL_DOMAIN (sym), domain)) other = sym; } return other; } /* See block.h. */ struct symbol * block_find_symbol (const struct block *block, const char *name, const domain_enum domain, block_symbol_matcher_ftype *matcher, void *data) { struct block_iterator iter; struct symbol *sym; lookup_name_info lookup_name (name, symbol_name_match_type::FULL); /* Verify BLOCK is STATIC_BLOCK or GLOBAL_BLOCK. */ gdb_assert (BLOCK_SUPERBLOCK (block) == NULL || BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL); ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym) { /* MATCHER is deliberately called second here so that it never sees a non-domain-matching symbol. */ if (symbol_matches_domain (SYMBOL_LANGUAGE (sym), SYMBOL_DOMAIN (sym), domain) && matcher (sym, data)) return sym; } return NULL; } /* See block.h. */ int block_find_non_opaque_type (struct symbol *sym, void *data) { return !TYPE_IS_OPAQUE (SYMBOL_TYPE (sym)); } /* See block.h. */ int block_find_non_opaque_type_preferred (struct symbol *sym, void *data) { struct symbol **best = (struct symbol **) data; if (!TYPE_IS_OPAQUE (SYMBOL_TYPE (sym))) return 1; *best = sym; return 0; }