binutils-gdb/gdb/block.c

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/* Block-related functions for the GNU debugger, GDB.
Copyright (C) 2003-2017 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 <http://www.gnu.org/licenses/>. */
#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 char *name,
symbol_compare_ftype *compare,
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,
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))
{
struct symbol *other = NULL;
ALL_BLOCK_SYMBOLS_WITH_NAME (block, 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, 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;
/* 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, name, strcmp_iw, &dict_iter);
sym != NULL;
sym = dict_iter_match_next (name, strcmp_iw, &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;
/* 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, 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;
}