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binutils-gdb/gdb/cp-namespace.c

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/* Helper routines for C++ support in GDB.
Copyright (C) 2003, 2004, 2007, 2008, 2009 Free Software Foundation, Inc.
Contributed by David Carlton and by Kealia, 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 "cp-support.h"
#include "gdb_obstack.h"
#include "symtab.h"
#include "symfile.h"
#include "gdb_assert.h"
#include "block.h"
#include "objfiles.h"
#include "gdbtypes.h"
#include "dictionary.h"
#include "command.h"
#include "frame.h"
/* List of using directives that are active in the current file. */
static struct using_direct *using_list;
static struct using_direct *cp_add_using (const char *name,
unsigned int inner_len,
unsigned int outer_len,
struct using_direct *next);
static struct using_direct *cp_copy_usings (struct using_direct *using,
struct obstack *obstack);
static struct symbol *lookup_namespace_scope (const char *name,
const char *linkage_name,
const struct block *block,
const domain_enum domain,
const char *scope,
int scope_len);
static struct symbol *lookup_symbol_file (const char *name,
const char *linkage_name,
const struct block *block,
const domain_enum domain,
int anonymous_namespace);
static struct type *cp_lookup_transparent_type_loop (const char *name,
const char *scope,
int scope_len);
static void initialize_namespace_symtab (struct objfile *objfile);
static struct block *get_possible_namespace_block (struct objfile *objfile);
static void free_namespace_block (struct symtab *symtab);
static int check_possible_namespace_symbols_loop (const char *name,
int len,
struct objfile *objfile);
static int check_one_possible_namespace_symbol (const char *name,
int len,
struct objfile *objfile);
static struct symbol *lookup_possible_namespace_symbol (const char *name);
static void maintenance_cplus_namespace (char *args, int from_tty);
/* Set up support for dealing with C++ namespace info in the current
symtab. */
void cp_initialize_namespace ()
{
using_list = NULL;
}
/* Add all the using directives we've gathered to the current symtab.
STATIC_BLOCK should be the symtab's static block; OBSTACK is used
for allocation. */
void
cp_finalize_namespace (struct block *static_block,
struct obstack *obstack)
{
if (using_list != NULL)
{
block_set_using (static_block,
cp_copy_usings (using_list, obstack),
obstack);
using_list = NULL;
}
}
/* Check to see if SYMBOL refers to an object contained within an
anonymous namespace; if so, add an appropriate using directive. */
/* Optimize away strlen ("(anonymous namespace)"). */
#define ANONYMOUS_NAMESPACE_LEN 21
void
cp_scan_for_anonymous_namespaces (const struct symbol *symbol)
{
if (SYMBOL_DEMANGLED_NAME (symbol) != NULL)
{
const char *name = SYMBOL_DEMANGLED_NAME (symbol);
unsigned int previous_component;
unsigned int next_component;
const char *len;
/* Start with a quick-and-dirty check for mention of "(anonymous
namespace)". */
if (!cp_is_anonymous (name))
return;
previous_component = 0;
next_component = cp_find_first_component (name + previous_component);
while (name[next_component] == ':')
{
if ((next_component - previous_component) == ANONYMOUS_NAMESPACE_LEN
&& strncmp (name + previous_component,
"(anonymous namespace)",
ANONYMOUS_NAMESPACE_LEN) == 0)
{
/* We've found a component of the name that's an
anonymous namespace. So add symbols in it to the
namespace given by the previous component if there is
one, or to the global namespace if there isn't. */
cp_add_using_directive (name,
previous_component == 0
? 0 : previous_component - 2,
next_component);
}
/* The "+ 2" is for the "::". */
previous_component = next_component + 2;
next_component = (previous_component
+ cp_find_first_component (name
+ previous_component));
}
}
}
/* Add a using directive to using_list. NAME is the start of a string
that should contain the namespaces we want to add as initial
substrings, OUTER_LENGTH is the end of the outer namespace, and
INNER_LENGTH is the end of the inner namespace. If the using
directive in question has already been added, don't add it
twice. */
void
cp_add_using_directive (const char *name, unsigned int outer_length,
unsigned int inner_length)
{
struct using_direct *current;
struct using_direct *new;
/* Has it already been added? */
for (current = using_list; current != NULL; current = current->next)
{
if ((strncmp (current->inner, name, inner_length) == 0)
&& (strlen (current->inner) == inner_length)
&& (strlen (current->outer) == outer_length))
return;
}
using_list = cp_add_using (name, inner_length, outer_length,
using_list);
}
/* Record the namespace that the function defined by SYMBOL was
defined in, if necessary. BLOCK is the associated block; use
OBSTACK for allocation. */
void
cp_set_block_scope (const struct symbol *symbol,
struct block *block,
struct obstack *obstack,
const char *processing_current_prefix,
int processing_has_namespace_info)
{
if (processing_has_namespace_info)
{
block_set_scope
(block, obsavestring (processing_current_prefix,
strlen (processing_current_prefix),
obstack),
obstack);
}
else if (SYMBOL_DEMANGLED_NAME (symbol) != NULL)
{
/* Try to figure out the appropriate namespace from the
demangled name. */
/* FIXME: carlton/2003-04-15: If the function in question is
a method of a class, the name will actually include the
name of the class as well. This should be harmless, but
is a little unfortunate. */
const char *name = SYMBOL_DEMANGLED_NAME (symbol);
unsigned int prefix_len = cp_entire_prefix_len (name);
block_set_scope (block,
obsavestring (name, prefix_len, obstack),
obstack);
}
}
/* Test whether or not NAMESPACE looks like it mentions an anonymous
namespace; return nonzero if so. */
int
cp_is_anonymous (const char *namespace)
{
return (strstr (namespace, "(anonymous namespace)")
!= NULL);
}
/* Create a new struct using direct whose inner namespace is the
initial substring of NAME of leng INNER_LEN and whose outer
namespace is the initial substring of NAME of length OUTER_LENGTH.
Set its next member in the linked list to NEXT; allocate all memory
using xmalloc. It copies the strings, so NAME can be a temporary
string. */
static struct using_direct *
cp_add_using (const char *name,
unsigned int inner_len,
unsigned int outer_len,
struct using_direct *next)
{
struct using_direct *retval;
gdb_assert (outer_len < inner_len);
retval = xmalloc (sizeof (struct using_direct));
retval->inner = savestring (name, inner_len);
retval->outer = savestring (name, outer_len);
retval->next = next;
return retval;
}
/* Make a copy of the using directives in the list pointed to by
USING, using OBSTACK to allocate memory. Free all memory pointed
to by USING via xfree. */
static struct using_direct *
cp_copy_usings (struct using_direct *using,
struct obstack *obstack)
{
if (using == NULL)
{
return NULL;
}
else
{
struct using_direct *retval
= obstack_alloc (obstack, sizeof (struct using_direct));
retval->inner = obsavestring (using->inner, strlen (using->inner),
obstack);
retval->outer = obsavestring (using->outer, strlen (using->outer),
obstack);
retval->next = cp_copy_usings (using->next, obstack);
xfree (using->inner);
xfree (using->outer);
xfree (using);
return retval;
}
}
/* The C++-specific version of name lookup for static and global
names. This makes sure that names get looked for in all namespaces
that are in scope. NAME is the natural name of the symbol that
we're looking for, LINKAGE_NAME (which is optional) is its linkage
name, BLOCK is the block that we're searching within, DOMAIN says
what kind of symbols we're looking for, and if SYMTAB is non-NULL,
we should store the symtab where we found the symbol in it. */
struct symbol *
cp_lookup_symbol_nonlocal (const char *name,
const char *linkage_name,
const struct block *block,
const domain_enum domain)
{
return lookup_namespace_scope (name, linkage_name, block, domain,
block_scope (block), 0);
}
/* Lookup NAME at namespace scope (or, in C terms, in static and
global variables). SCOPE is the namespace that the current
function is defined within; only consider namespaces whose length
is at least SCOPE_LEN. Other arguments are as in
cp_lookup_symbol_nonlocal.
For example, if we're within a function A::B::f and looking for a
symbol x, this will get called with NAME = "x", SCOPE = "A::B", and
SCOPE_LEN = 0. It then calls itself with NAME and SCOPE the same,
but with SCOPE_LEN = 1. And then it calls itself with NAME and
SCOPE the same, but with SCOPE_LEN = 4. This third call looks for
"A::B::x"; if it doesn't find it, then the second call looks for
"A::x", and if that call fails, then the first call looks for
"x". */
static struct symbol *
lookup_namespace_scope (const char *name,
const char *linkage_name,
const struct block *block,
const domain_enum domain,
const char *scope,
int scope_len)
{
char *namespace;
if (scope[scope_len] != '\0')
{
/* Recursively search for names in child namespaces first. */
struct symbol *sym;
int new_scope_len = scope_len;
/* If the current scope is followed by "::", skip past that. */
if (new_scope_len != 0)
{
gdb_assert (scope[new_scope_len] == ':');
new_scope_len += 2;
}
new_scope_len += cp_find_first_component (scope + new_scope_len);
sym = lookup_namespace_scope (name, linkage_name, block,
domain, scope, new_scope_len);
if (sym != NULL)
return sym;
}
/* Okay, we didn't find a match in our children, so look for the
name in the current namespace. */
namespace = alloca (scope_len + 1);
strncpy (namespace, scope, scope_len);
namespace[scope_len] = '\0';
return cp_lookup_symbol_namespace (namespace, name, linkage_name,
block, domain);
}
/* Look up NAME in the C++ namespace NAMESPACE, applying the using
directives that are active in BLOCK. Other arguments are as in
cp_lookup_symbol_nonlocal. */
struct symbol *
cp_lookup_symbol_namespace (const char *namespace,
const char *name,
const char *linkage_name,
const struct block *block,
const domain_enum domain)
{
const struct using_direct *current;
struct symbol *sym;
/* First, go through the using directives. If any of them add new
names to the namespace we're searching in, see if we can find a
match by applying them. */
for (current = block_using (block);
current != NULL;
current = current->next)
{
if (strcmp (namespace, current->outer) == 0)
{
sym = cp_lookup_symbol_namespace (current->inner,
name,
linkage_name,
block,
domain);
if (sym != NULL)
return sym;
}
}
/* We didn't find anything by applying any of the using directives
that are still applicable; so let's see if we've got a match
using the current namespace. */
if (namespace[0] == '\0')
{
return lookup_symbol_file (name, linkage_name, block,
domain, 0);
}
else
{
char *concatenated_name
= alloca (strlen (namespace) + 2 + strlen (name) + 1);
strcpy (concatenated_name, namespace);
strcat (concatenated_name, "::");
strcat (concatenated_name, name);
sym = lookup_symbol_file (concatenated_name, linkage_name,
block, domain,
cp_is_anonymous (namespace));
return sym;
}
}
/* Look up NAME in BLOCK's static block and in global blocks. If
ANONYMOUS_NAMESPACE is nonzero, the symbol in question is located
within an anonymous namespace. Other arguments are as in
cp_lookup_symbol_nonlocal. */
static struct symbol *
lookup_symbol_file (const char *name,
const char *linkage_name,
const struct block *block,
const domain_enum domain,
int anonymous_namespace)
{
struct symbol *sym = NULL;
sym = lookup_symbol_static (name, linkage_name, block, domain);
if (sym != NULL)
return sym;
if (anonymous_namespace)
{
/* Symbols defined in anonymous namespaces have external linkage
but should be treated as local to a single file nonetheless.
So we only search the current file's global block. */
const struct block *global_block = block_global_block (block);
if (global_block != NULL)
sym = lookup_symbol_aux_block (name, linkage_name, global_block,
domain);
}
else
{
sym = lookup_symbol_global (name, linkage_name, block, domain);
}
if (sym != NULL)
return sym;
/* Now call "lookup_possible_namespace_symbol". Symbols in here
claim to be associated to namespaces, but this claim might be
incorrect: the names in question might actually correspond to
classes instead of namespaces. But if they correspond to
classes, then we should have found a match for them above. So if
we find them now, they should be genuine. */
/* FIXME: carlton/2003-06-12: This is a hack and should eventually
be deleted: see comments below. */
if (domain == VAR_DOMAIN)
{
sym = lookup_possible_namespace_symbol (name);
if (sym != NULL)
return sym;
}
return NULL;
}
/* Look up a type named NESTED_NAME that is nested inside the C++
class or namespace given by PARENT_TYPE, from within the context
given by BLOCK. Return NULL if there is no such nested type. */
struct type *
cp_lookup_nested_type (struct type *parent_type,
const char *nested_name,
const struct block *block)
{
switch (TYPE_CODE (parent_type))
{
case TYPE_CODE_STRUCT:
case TYPE_CODE_NAMESPACE:
{
/* NOTE: carlton/2003-11-10: We don't treat C++ class members
of classes like, say, data or function members. Instead,
they're just represented by symbols whose names are
qualified by the name of the surrounding class. This is
just like members of namespaces; in particular,
lookup_symbol_namespace works when looking them up. */
const char *parent_name = TYPE_TAG_NAME (parent_type);
struct symbol *sym = cp_lookup_symbol_namespace (parent_name,
nested_name,
NULL,
block,
VAR_DOMAIN);
if (sym == NULL || SYMBOL_CLASS (sym) != LOC_TYPEDEF)
return NULL;
else
return SYMBOL_TYPE (sym);
}
default:
internal_error (__FILE__, __LINE__,
_("cp_lookup_nested_type called on a non-aggregate type."));
}
}
/* The C++-version of lookup_transparent_type. */
/* FIXME: carlton/2004-01-16: The problem that this is trying to
address is that, unfortunately, sometimes NAME is wrong: it may not
include the name of namespaces enclosing the type in question.
lookup_transparent_type gets called when the the type in question
is a declaration, and we're trying to find its definition; but, for
declarations, our type name deduction mechanism doesn't work.
There's nothing we can do to fix this in general, I think, in the
absence of debug information about namespaces (I've filed PR
gdb/1511 about this); until such debug information becomes more
prevalent, one heuristic which sometimes looks is to search for the
definition in namespaces containing the current namespace.
We should delete this functions once the appropriate debug
information becomes more widespread. (GCC 3.4 will be the first
released version of GCC with such information.) */
struct type *
cp_lookup_transparent_type (const char *name)
{
/* First, try the honest way of looking up the definition. */
struct type *t = basic_lookup_transparent_type (name);
const char *scope;
if (t != NULL)
return t;
/* If that doesn't work and we're within a namespace, look there
instead. */
scope = block_scope (get_selected_block (0));
if (scope[0] == '\0')
return NULL;
return cp_lookup_transparent_type_loop (name, scope, 0);
}
/* Lookup the the type definition associated to NAME in
namespaces/classes containing SCOPE whose name is strictly longer
than LENGTH. LENGTH must be the index of the start of a
component of SCOPE. */
static struct type *
cp_lookup_transparent_type_loop (const char *name, const char *scope,
int length)
{
int scope_length = length + cp_find_first_component (scope + length);
char *full_name;
/* If the current scope is followed by "::", look in the next
component. */
if (scope[scope_length] == ':')
{
struct type *retval
= cp_lookup_transparent_type_loop (name, scope, scope_length + 2);
if (retval != NULL)
return retval;
}
full_name = alloca (scope_length + 2 + strlen (name) + 1);
strncpy (full_name, scope, scope_length);
strncpy (full_name + scope_length, "::", 2);
strcpy (full_name + scope_length + 2, name);
return basic_lookup_transparent_type (full_name);
}
/* Now come functions for dealing with symbols associated to
namespaces. (They're used to store the namespaces themselves, not
objects that live in the namespaces.) These symbols come in two
varieties: if we run into a DW_TAG_namespace DIE, then we know that
we have a namespace, so dwarf2read.c creates a symbol for it just
like normal. But, unfortunately, versions of GCC through at least
3.3 don't generate those DIE's. Our solution is to try to guess
their existence by looking at demangled names. This might cause us
to misidentify classes as namespaces, however. So we put those
symbols in a special block (one per objfile), and we only search
that block as a last resort. */
/* FIXME: carlton/2003-06-12: Once versions of GCC that generate
DW_TAG_namespace have been out for a year or two, we should get rid
of all of this "possible namespace" nonsense. */
/* Allocate everything necessary for the possible namespace block
associated to OBJFILE. */
static void
initialize_namespace_symtab (struct objfile *objfile)
{
struct symtab *namespace_symtab;
struct blockvector *bv;
struct block *bl;
namespace_symtab = allocate_symtab ("<<C++-namespaces>>", objfile);
namespace_symtab->language = language_cplus;
namespace_symtab->free_code = free_nothing;
namespace_symtab->dirname = NULL;
bv = obstack_alloc (&objfile->objfile_obstack,
sizeof (struct blockvector)
+ FIRST_LOCAL_BLOCK * sizeof (struct block *));
BLOCKVECTOR_NBLOCKS (bv) = FIRST_LOCAL_BLOCK + 1;
BLOCKVECTOR (namespace_symtab) = bv;
/* Allocate empty GLOBAL_BLOCK and STATIC_BLOCK. */
bl = allocate_block (&objfile->objfile_obstack);
BLOCK_DICT (bl) = dict_create_linear (&objfile->objfile_obstack,
NULL);
BLOCKVECTOR_BLOCK (bv, GLOBAL_BLOCK) = bl;
bl = allocate_block (&objfile->objfile_obstack);
BLOCK_DICT (bl) = dict_create_linear (&objfile->objfile_obstack,
NULL);
BLOCKVECTOR_BLOCK (bv, STATIC_BLOCK) = bl;
/* Allocate the possible namespace block; we put it where the first
local block will live, though I don't think there's any need to
pretend that it's actually a local block (e.g. by setting
BLOCK_SUPERBLOCK appropriately). We don't use the global or
static block because we don't want it searched during the normal
search of all global/static blocks in lookup_symbol: we only want
it used as a last resort. */
/* NOTE: carlton/2003-09-11: I considered not associating the fake
symbols to a block/symtab at all. But that would cause problems
with lookup_symbol's SYMTAB argument and with block_found, so
having a symtab/block for this purpose seems like the best
solution for now. */
bl = allocate_block (&objfile->objfile_obstack);
BLOCK_DICT (bl) = dict_create_hashed_expandable ();
BLOCKVECTOR_BLOCK (bv, FIRST_LOCAL_BLOCK) = bl;
namespace_symtab->free_func = free_namespace_block;
objfile->cp_namespace_symtab = namespace_symtab;
}
/* Locate the possible namespace block associated to OBJFILE,
allocating it if necessary. */
static struct block *
get_possible_namespace_block (struct objfile *objfile)
{
if (objfile->cp_namespace_symtab == NULL)
initialize_namespace_symtab (objfile);
return BLOCKVECTOR_BLOCK (BLOCKVECTOR (objfile->cp_namespace_symtab),
FIRST_LOCAL_BLOCK);
}
/* Free the dictionary associated to the possible namespace block. */
static void
free_namespace_block (struct symtab *symtab)
{
struct block *possible_namespace_block;
possible_namespace_block = BLOCKVECTOR_BLOCK (BLOCKVECTOR (symtab),
FIRST_LOCAL_BLOCK);
gdb_assert (possible_namespace_block != NULL);
dict_free (BLOCK_DICT (possible_namespace_block));
}
/* Ensure that there are symbols in the possible namespace block
associated to OBJFILE for all initial substrings of NAME that look
like namespaces or classes. NAME should end in a member variable:
it shouldn't consist solely of namespaces. */
void
cp_check_possible_namespace_symbols (const char *name, struct objfile *objfile)
{
check_possible_namespace_symbols_loop (name,
cp_find_first_component (name),
objfile);
}
/* This is a helper loop for cp_check_possible_namespace_symbols; it
ensures that there are symbols in the possible namespace block
associated to OBJFILE for all namespaces that are initial
substrings of NAME of length at least LEN. It returns 1 if a
previous loop had already created the shortest such symbol and 0
otherwise.
This function assumes that if there is already a symbol associated
to a substring of NAME of a given length, then there are already
symbols associated to all substrings of NAME whose length is less
than that length. So if cp_check_possible_namespace_symbols has
been called once with argument "A::B::C::member", then that will
create symbols "A", "A::B", and "A::B::C". If it is then later
called with argument "A::B::D::member", then the new call will
generate a new symbol for "A::B::D", but once it sees that "A::B"
has already been created, it doesn't bother checking to see if "A"
has also been created. */
static int
check_possible_namespace_symbols_loop (const char *name, int len,
struct objfile *objfile)
{
if (name[len] == ':')
{
int done;
int next_len = len + 2;
next_len += cp_find_first_component (name + next_len);
done = check_possible_namespace_symbols_loop (name, next_len,
objfile);
if (!done)
done = check_one_possible_namespace_symbol (name, len, objfile);
return done;
}
else
return 0;
}
/* Check to see if there's already a possible namespace symbol in
OBJFILE whose name is the initial substring of NAME of length LEN.
If not, create one and return 0; otherwise, return 1. */
static int
check_one_possible_namespace_symbol (const char *name, int len,
struct objfile *objfile)
{
struct block *block = get_possible_namespace_block (objfile);
char *name_copy = alloca (len + 1);
struct symbol *sym;
memcpy (name_copy, name, len);
name_copy[len] = '\0';
sym = lookup_block_symbol (block, name_copy, NULL, VAR_DOMAIN);
if (sym == NULL)
{
struct type *type;
name_copy = obsavestring (name, len, &objfile->objfile_obstack);
type = init_type (TYPE_CODE_NAMESPACE, 0, 0, name_copy, objfile);
TYPE_TAG_NAME (type) = TYPE_NAME (type);
sym = obstack_alloc (&objfile->objfile_obstack, sizeof (struct symbol));
memset (sym, 0, sizeof (struct symbol));
SYMBOL_LANGUAGE (sym) = language_cplus;
SYMBOL_SET_NAMES (sym, name_copy, len, objfile);
SYMBOL_CLASS (sym) = LOC_TYPEDEF;
SYMBOL_TYPE (sym) = type;
SYMBOL_DOMAIN (sym) = VAR_DOMAIN;
dict_add_symbol (BLOCK_DICT (block), sym);
return 0;
}
else
return 1;
}
/* Look for a symbol named NAME in all the possible namespace blocks.
If one is found, return it. */
static struct symbol *
lookup_possible_namespace_symbol (const char *name)
{
struct objfile *objfile;
ALL_OBJFILES (objfile)
{
struct symbol *sym;
sym = lookup_block_symbol (get_possible_namespace_block (objfile),
name, NULL, VAR_DOMAIN);
if (sym != NULL)
return sym;
}
return NULL;
}
/* Print out all the possible namespace symbols. */
static void
maintenance_cplus_namespace (char *args, int from_tty)
{
struct objfile *objfile;
printf_unfiltered (_("Possible namespaces:\n"));
ALL_OBJFILES (objfile)
{
struct dict_iterator iter;
struct symbol *sym;
ALL_BLOCK_SYMBOLS (get_possible_namespace_block (objfile), iter, sym)
{
printf_unfiltered ("%s\n", SYMBOL_PRINT_NAME (sym));
}
}
}
void
_initialize_cp_namespace (void)
{
add_cmd ("namespace", class_maintenance, maintenance_cplus_namespace,
_("Print the list of possible C++ namespaces."),
&maint_cplus_cmd_list);
}
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