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/* Helper routines for C++ support in GDB.

   Copyright (C) 2003, 2004, 2007, 2008, 2009, 2010

   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"

#include "buildsym.h"

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);

/* 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)

            {

              int dest_len = (previous_component == 0 ? 0 : previous_component - 2);

              int src_len = next_component;

              char *dest = alloca (dest_len + 1);

              char *src = alloca (src_len + 1);

              memcpy (dest, name, dest_len);

              memcpy (src, name, src_len);

              dest[dest_len] = '\0';

              src[src_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 (dest, src, NULL);

            }

          /* 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. If the using directive in question

   has already been added, don't add it twice.  */

void

cp_add_using_directive (const char *dest, const char *src, const char *alias)

{

  struct using_direct *current;

  struct using_direct *new;

  /* Has it already been added?  */

  for (current = using_directives; current != NULL; current = current->next)

    {

      if (strcmp (current->import_src, src) == 0

          && strcmp (current->import_dest, dest) == 0)

        return;

    }

  using_directives = cp_add_using (dest, src, alias, using_directives);

}

/* 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 which imports the namespace SRC into the

   scope DEST.  ALIAS is the name of the imported namespace in the current

   scope.  If ALIAS is NULL then the namespace is known by its original name.

   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.  */

struct using_direct *

cp_add_using (const char *dest,

              const char *src,

              const char *alias,

              struct using_direct *next)

{

  struct using_direct *retval;

  retval = xmalloc (sizeof (struct using_direct));

  retval->import_src = savestring (src, strlen(src));

  retval->import_dest = savestring (dest, strlen(dest));

  if (alias != NULL)

    retval->alias = savestring (alias, strlen (alias));

  else

    retval->alias = NULL;

  retval->next = next;

  retval->searched = 0;

  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)

{

  struct symbol *sym;

  const char *scope = block_scope (block);

  sym = lookup_namespace_scope (name, linkage_name, block, domain, scope, 0);

  if (sym != NULL)

    return sym;

  return cp_lookup_symbol_namespace (scope, name, linkage_name, block, domain,

                                     1);

}

/* Look up NAME in the C++ namespace NAMESPACE. Other arguments are as in

   cp_lookup_symbol_nonlocal.  */

static struct symbol *

cp_lookup_symbol_in_namespace (const char *namespace,

                               const char *name,

                               const char *linkage_name,

                               const struct block *block,

                               const domain_enum domain)

{

  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);

      return lookup_symbol_file (concatenated_name, linkage_name,

                                 block, domain,cp_is_anonymous (namespace));

    }

}

/* Used for cleanups to reset the "searched" flag incase

   of an error.  */

static void

reset_directive_searched (void *data)

{

  struct using_direct *direct = data;

  direct->searched = 0;

}

/* Search for NAME by applying all import statements belonging

   to BLOCK which are applicable in SCOPE.

   If SEARCH_PARENTS the search will include imports which are applicable in

   parents of SCOPE.

   Example:

     namespace A{

       using namespace X;

       namespace B{

         using namespace Y;

       }

     }

   If SCOPE is "A::B" and SEARCH_PARENTS is true the imports of namespaces X

   and Y will be considered. If SEARCH_PARENTS is false only the import of Y

   is considered.  */

static struct symbol *

cp_lookup_symbol_imports (const char *scope,

                          const char *name,

                          const char *linkage_name,

                          const struct block *block,

                          const domain_enum domain,

                          const int search_parents)

{

  struct using_direct *current;

  struct symbol *sym;

  int len;

  int directive_match;

  struct cleanup *searched_cleanup;

  /* First, try to find the symbol in the given namespace.  */

  sym = cp_lookup_symbol_in_namespace (scope, name, linkage_name, block,

                                       domain);

  if (sym != NULL)

    return sym;

  /* 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)

    {

      len = strlen (current->import_dest);

      directive_match = (search_parents

                         ? (strncmp (scope, current->import_dest,

                                     strlen (current->import_dest)) == 0

                            && (len == 0

                                || scope[len] == ':' || scope[len] == '\0'))

                         : strcmp (scope, current->import_dest) == 0);

      /* If the import destination is the current scope or one of its ancestors then

         it is applicable.  */

      if (directive_match && !current->searched)

        {

        /* Mark this import as searched so that the recursive call does not

           search it again.  */

        current->searched = 1;

        searched_cleanup = make_cleanup (reset_directive_searched, current);

        if (current->alias != NULL && strcmp (name, current->alias) == 0)

          /* If the import is creating an alias and the alias matches the

             sought name.  Pass current->import_src as the NAME to direct the

             search towards the aliased namespace.  */

          {

            sym = cp_lookup_symbol_in_namespace (scope,

                                                 current->import_src,

                                                 linkage_name,

                                                 block,

                                                 domain);

          }

        else if (current->alias == NULL)

          {

            /* If this import statement creates no alias, pass current->inner as

               NAMESPACE to direct the search towards the imported namespace.  */

            sym = cp_lookup_symbol_imports (current->import_src,

                                            name,

                                            linkage_name,

                                            block,

                                            domain,

                                            0);

          }

        current->searched = 0;

        discard_cleanups (searched_cleanup);

        if (sym != NULL)

          return sym;

        }

    }

  return NULL;

}

 /* Searches for NAME in the current namespace, and by applying relevant import

    statements belonging to BLOCK and its parents. SCOPE is the namespace scope

    of the context in which the search is being evaluated.  */

struct symbol*

cp_lookup_symbol_namespace (const char *scope,

                            const char *name,

                            const char *linkage_name,

                            const struct block *block,

                            const domain_enum domain,

                            const int search_parents)

{

  struct symbol *sym;

  /* Search for name in namespaces imported to this and parent blocks.  */

  while (block != NULL)

    {

      sym = cp_lookup_symbol_imports (scope, name, linkage_name, block, domain,

                                      search_parents);

      if (sym)

        return sym;

      block = BLOCK_SUPERBLOCK (block);

    }

  return NULL;

}

/* 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_in_namespace (namespace, name, linkage_name,

                                        block, domain);

}

/* 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_in_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);

}