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jeremybenn |
/* Type based alias analysis.
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Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010
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Free Software Foundation, Inc.
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Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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/* This pass determines which types in the program contain only
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instances that are completely encapsulated by the compilation unit.
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Those types that are encapsulated must also pass the further
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requirement that there be no bad operations on any instances of
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those types.
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A great deal of freedom in compilation is allowed for the instances
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of those types that pass these conditions.
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*/
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/* The code in this module is called by the ipa pass manager. It
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should be one of the later passes since its information is used by
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the rest of the compilation. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "tree.h"
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#include "tree-flow.h"
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#include "tree-inline.h"
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#include "tree-pass.h"
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#include "langhooks.h"
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#include "pointer-set.h"
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#include "splay-tree.h"
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#include "ggc.h"
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#include "ipa-utils.h"
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#include "ipa-type-escape.h"
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#include "gimple.h"
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#include "cgraph.h"
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#include "output.h"
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#include "flags.h"
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#include "timevar.h"
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#include "diagnostic.h"
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#include "langhooks.h"
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/* Some of the aliasing is called very early, before this phase is
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called. To assure that this is not a problem, we keep track of if
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this phase has been run. */
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static bool initialized = false;
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/* Scratch bitmap for avoiding work. */
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static bitmap been_there_done_that;
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static bitmap bitmap_tmp;
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/* There are two levels of escape that types can undergo.
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EXPOSED_PARAMETER - some instance of the variable is
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passed by value into an externally visible function or some
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instance of the variable is passed out of an externally visible
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function as a return value. In this case any of the fields of the
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variable that are pointer types end up having their types marked as
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FULL_ESCAPE.
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FULL_ESCAPE - when bad things happen to good types. One of the
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following things happens to the type: (a) either an instance of the
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variable has its address passed to an externally visible function,
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(b) the address is taken and some bad cast happens to the address
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or (c) explicit arithmetic is done to the address.
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*/
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enum escape_t
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{
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EXPOSED_PARAMETER,
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FULL_ESCAPE
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};
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/* The following two bit vectors global_types_* correspond to
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previous cases above. During the analysis phase, a bit is set in
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one of these vectors if an operation of the offending class is
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discovered to happen on the associated type. */
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static bitmap global_types_exposed_parameter;
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static bitmap global_types_full_escape;
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/* All of the types seen in this compilation unit. */
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static bitmap global_types_seen;
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/* Reverse map to take a canon uid and map it to a canon type. Uid's
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are never manipulated unless they are associated with a canon
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type. */
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static splay_tree uid_to_canon_type;
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/* Internal structure of type mapping code. This maps a canon type
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name to its canon type. */
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static splay_tree all_canon_types;
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/* Map from type clones to the single canon type. */
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static splay_tree type_to_canon_type;
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/* A splay tree of bitmaps. An element X in the splay tree has a bit
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set in its bitmap at TYPE_UID (TYPE_MAIN_VARIANT (Y)) if there was
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an operation in the program of the form "&X.Y". */
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static splay_tree uid_to_addressof_down_map;
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/* A splay tree of bitmaps. An element Y in the splay tree has a bit
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set in its bitmap at TYPE_UID (TYPE_MAIN_VARIANT (X)) if there was
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an operation in the program of the form "&X.Y". */
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static splay_tree uid_to_addressof_up_map;
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/* Tree to hold the subtype maps used to mark subtypes of escaped
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types. */
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static splay_tree uid_to_subtype_map;
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/* Records tree nodes seen in cgraph_create_edges. Simply using
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walk_tree_without_duplicates doesn't guarantee each node is visited
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once because it gets a new htab upon each recursive call from
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scan_for_refs. */
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static struct pointer_set_t *visited_nodes;
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/* Visited stmts by walk_use_def_chains function because it's called
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recursively. */
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static struct pointer_set_t *visited_stmts;
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static bitmap_obstack ipa_obstack;
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/* Static functions from this file that are used
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before being defined. */
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static unsigned int look_for_casts (tree);
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static bool is_cast_from_non_pointer (tree, gimple, void *);
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/* Get the name of TYPE or return the string "<UNNAMED>". */
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static const char*
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get_name_of_type (tree type)
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{
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tree name = TYPE_NAME (type);
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if (!name)
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/* Unnamed type, do what you like here. */
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return "<UNNAMED>";
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/* It will be a TYPE_DECL in the case of a typedef, otherwise, an
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identifier_node */
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if (TREE_CODE (name) == TYPE_DECL)
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{
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/* Each DECL has a DECL_NAME field which contains an
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IDENTIFIER_NODE. (Some decls, most often labels, may have
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zero as the DECL_NAME). */
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if (DECL_NAME (name))
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return IDENTIFIER_POINTER (DECL_NAME (name));
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else
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/* Unnamed type, do what you like here. */
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return "<UNNAMED>";
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}
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else if (TREE_CODE (name) == IDENTIFIER_NODE)
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return IDENTIFIER_POINTER (name);
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else
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return "<UNNAMED>";
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}
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struct type_brand_s
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{
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const char* name;
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int seq;
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};
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/* Splay tree comparison function on type_brand_s structures. */
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static int
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compare_type_brand (splay_tree_key sk1, splay_tree_key sk2)
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{
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struct type_brand_s * k1 = (struct type_brand_s *) sk1;
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struct type_brand_s * k2 = (struct type_brand_s *) sk2;
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int value = strcmp(k1->name, k2->name);
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if (value == 0)
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return k2->seq - k1->seq;
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else
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return value;
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}
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/* All of the "unique_type" code is a hack to get around the sleazy
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implementation used to compile more than file. Currently gcc does
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not get rid of multiple instances of the same type that have been
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collected from different compilation units. */
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/* This is a trivial algorithm for removing duplicate types. This
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would not work for any language that used structural equivalence as
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the basis of its type system. */
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/* Return TYPE if no type compatible with TYPE has been seen so far,
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otherwise return a type compatible with TYPE that has already been
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processed. */
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static tree
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discover_unique_type (tree type)
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{
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struct type_brand_s * brand = XNEW (struct type_brand_s);
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int i = 0;
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splay_tree_node result;
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brand->name = get_name_of_type (type);
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while (1)
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{
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brand->seq = i++;
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result = splay_tree_lookup (all_canon_types, (splay_tree_key) brand);
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if (result)
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{
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/* Create an alias since this is just the same as
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other_type. */
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tree other_type = (tree) result->value;
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if (types_compatible_p (type, other_type))
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{
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free (brand);
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/* Insert this new type as an alias for other_type. */
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splay_tree_insert (type_to_canon_type,
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(splay_tree_key) type,
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(splay_tree_value) other_type);
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return other_type;
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}
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/* Not compatible, look for next instance with same name. */
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}
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else
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{
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/* No more instances, create new one since this is the first
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time we saw this type. */
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brand->seq = i++;
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/* Insert the new brand. */
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splay_tree_insert (all_canon_types,
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(splay_tree_key) brand,
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(splay_tree_value) type);
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/* Insert this new type as an alias for itself. */
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splay_tree_insert (type_to_canon_type,
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(splay_tree_key) type,
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(splay_tree_value) type);
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/* Insert the uid for reverse lookup; */
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splay_tree_insert (uid_to_canon_type,
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(splay_tree_key) TYPE_UID (type),
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(splay_tree_value) type);
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bitmap_set_bit (global_types_seen, TYPE_UID (type));
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return type;
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}
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}
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}
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/* Return true if TYPE is one of the type classes that we are willing
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to analyze. This skips the goofy types like arrays of pointers to
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methods. */
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static bool
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type_to_consider (tree type)
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{
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/* Strip the *'s off. */
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type = TYPE_MAIN_VARIANT (type);
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while (POINTER_TYPE_P (type) || TREE_CODE (type) == ARRAY_TYPE)
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type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
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switch (TREE_CODE (type))
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{
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case BOOLEAN_TYPE:
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case COMPLEX_TYPE:
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case ENUMERAL_TYPE:
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case INTEGER_TYPE:
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case QUAL_UNION_TYPE:
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case REAL_TYPE:
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case FIXED_POINT_TYPE:
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case RECORD_TYPE:
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case UNION_TYPE:
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case VECTOR_TYPE:
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case VOID_TYPE:
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return true;
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default:
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return false;
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}
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}
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/* Get the canon type of TYPE. If SEE_THRU_PTRS is true, remove all
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the POINTER_TOs and if SEE_THRU_ARRAYS is true, remove all of the
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ARRAY_OFs and POINTER_TOs. */
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static tree
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get_canon_type (tree type, bool see_thru_ptrs, bool see_thru_arrays)
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{
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splay_tree_node result;
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298 |
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/* Strip the *'s off. */
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if (!type || !type_to_consider (type))
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return NULL;
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301 |
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type = TYPE_MAIN_VARIANT (type);
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if (see_thru_arrays)
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while (POINTER_TYPE_P (type) || TREE_CODE (type) == ARRAY_TYPE)
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type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
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else if (see_thru_ptrs)
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while (POINTER_TYPE_P (type))
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type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
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310 |
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result = splay_tree_lookup (type_to_canon_type, (splay_tree_key) type);
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312 |
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313 |
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if (result == NULL)
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return discover_unique_type (type);
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else return (tree) result->value;
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}
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/* Same as GET_CANON_TYPE, except return the TYPE_ID rather than the
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TYPE. */
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static int
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get_canon_type_uid (tree type, bool see_thru_ptrs, bool see_thru_arrays)
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{
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324 |
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type = get_canon_type (type, see_thru_ptrs, see_thru_arrays);
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if (type)
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return TYPE_UID(type);
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else return 0;
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}
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329 |
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330 |
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/* Return 0 if TYPE is a record or union type. Return a positive
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331 |
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number if TYPE is a pointer to a record or union. The number is
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the number of pointer types stripped to get to the record or union
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type. Return -1 if TYPE is none of the above. */
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334 |
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int
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ipa_type_escape_star_count_of_interesting_type (tree type)
|
337 |
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{
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338 |
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int count = 0;
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339 |
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/* Strip the *'s off. */
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340 |
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if (!type)
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return -1;
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342 |
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type = TYPE_MAIN_VARIANT (type);
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while (POINTER_TYPE_P (type))
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{
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type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
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count++;
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}
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348 |
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349 |
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/* We are interested in records, and unions only. */
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350 |
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if (TREE_CODE (type) == RECORD_TYPE
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|| TREE_CODE (type) == QUAL_UNION_TYPE
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|| TREE_CODE (type) == UNION_TYPE)
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return count;
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else
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return -1;
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356 |
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}
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357 |
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|
358 |
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|
359 |
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/* Return 0 if TYPE is a record or union type. Return a positive
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360 |
|
|
number if TYPE is a pointer to a record or union. The number is
|
361 |
|
|
the number of pointer types stripped to get to the record or union
|
362 |
|
|
type. Return -1 if TYPE is none of the above. */
|
363 |
|
|
|
364 |
|
|
int
|
365 |
|
|
ipa_type_escape_star_count_of_interesting_or_array_type (tree type)
|
366 |
|
|
{
|
367 |
|
|
int count = 0;
|
368 |
|
|
/* Strip the *'s off. */
|
369 |
|
|
if (!type)
|
370 |
|
|
return -1;
|
371 |
|
|
type = TYPE_MAIN_VARIANT (type);
|
372 |
|
|
while (POINTER_TYPE_P (type) || TREE_CODE (type) == ARRAY_TYPE)
|
373 |
|
|
{
|
374 |
|
|
type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
|
375 |
|
|
count++;
|
376 |
|
|
}
|
377 |
|
|
|
378 |
|
|
/* We are interested in records, and unions only. */
|
379 |
|
|
if (TREE_CODE (type) == RECORD_TYPE
|
380 |
|
|
|| TREE_CODE (type) == QUAL_UNION_TYPE
|
381 |
|
|
|| TREE_CODE (type) == UNION_TYPE)
|
382 |
|
|
return count;
|
383 |
|
|
else
|
384 |
|
|
return -1;
|
385 |
|
|
}
|
386 |
|
|
|
387 |
|
|
|
388 |
|
|
/* Return true if the record, or union TYPE passed in escapes this
|
389 |
|
|
compilation unit. Note that all of the pointer-to's are removed
|
390 |
|
|
before testing since these may not be correct. */
|
391 |
|
|
|
392 |
|
|
bool
|
393 |
|
|
ipa_type_escape_type_contained_p (tree type)
|
394 |
|
|
{
|
395 |
|
|
if (!initialized)
|
396 |
|
|
return false;
|
397 |
|
|
return !bitmap_bit_p (global_types_full_escape,
|
398 |
|
|
get_canon_type_uid (type, true, false));
|
399 |
|
|
}
|
400 |
|
|
|
401 |
|
|
/* Return true if a modification to a field of type FIELD_TYPE cannot
|
402 |
|
|
clobber a record of RECORD_TYPE. */
|
403 |
|
|
|
404 |
|
|
bool
|
405 |
|
|
ipa_type_escape_field_does_not_clobber_p (tree record_type, tree field_type)
|
406 |
|
|
{
|
407 |
|
|
splay_tree_node result;
|
408 |
|
|
int uid;
|
409 |
|
|
|
410 |
|
|
if (!initialized)
|
411 |
|
|
return false;
|
412 |
|
|
|
413 |
|
|
/* Strip off all of the pointer tos on the record type. Strip the
|
414 |
|
|
same number of pointer tos from the field type. If the field
|
415 |
|
|
type has fewer, it could not have been aliased. */
|
416 |
|
|
record_type = TYPE_MAIN_VARIANT (record_type);
|
417 |
|
|
field_type = TYPE_MAIN_VARIANT (field_type);
|
418 |
|
|
while (POINTER_TYPE_P (record_type))
|
419 |
|
|
{
|
420 |
|
|
record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_type));
|
421 |
|
|
if (POINTER_TYPE_P (field_type))
|
422 |
|
|
field_type = TYPE_MAIN_VARIANT (TREE_TYPE (field_type));
|
423 |
|
|
else
|
424 |
|
|
/* However, if field_type is a union, this quick test is not
|
425 |
|
|
correct since one of the variants of the union may be a
|
426 |
|
|
pointer to type and we cannot see across that here. So we
|
427 |
|
|
just strip the remaining pointer tos off the record type
|
428 |
|
|
and fall thru to the more precise code. */
|
429 |
|
|
if (TREE_CODE (field_type) == QUAL_UNION_TYPE
|
430 |
|
|
|| TREE_CODE (field_type) == UNION_TYPE)
|
431 |
|
|
{
|
432 |
|
|
while (POINTER_TYPE_P (record_type))
|
433 |
|
|
record_type = TYPE_MAIN_VARIANT (TREE_TYPE (record_type));
|
434 |
|
|
break;
|
435 |
|
|
}
|
436 |
|
|
else
|
437 |
|
|
return true;
|
438 |
|
|
}
|
439 |
|
|
|
440 |
|
|
record_type = get_canon_type (record_type, true, true);
|
441 |
|
|
/* The record type must be contained. The field type may
|
442 |
|
|
escape. */
|
443 |
|
|
if (!ipa_type_escape_type_contained_p (record_type))
|
444 |
|
|
return false;
|
445 |
|
|
|
446 |
|
|
uid = TYPE_UID (record_type);
|
447 |
|
|
result = splay_tree_lookup (uid_to_addressof_down_map, (splay_tree_key) uid);
|
448 |
|
|
|
449 |
|
|
if (result)
|
450 |
|
|
{
|
451 |
|
|
bitmap field_type_map = (bitmap) result->value;
|
452 |
|
|
uid = get_canon_type_uid (field_type, true, true);
|
453 |
|
|
/* If the bit is there, the address was taken. If not, it
|
454 |
|
|
wasn't. */
|
455 |
|
|
return !bitmap_bit_p (field_type_map, uid);
|
456 |
|
|
}
|
457 |
|
|
else
|
458 |
|
|
/* No bitmap means no addresses were taken. */
|
459 |
|
|
return true;
|
460 |
|
|
}
|
461 |
|
|
|
462 |
|
|
|
463 |
|
|
/* Add TYPE to the suspect type set. Return true if the bit needed to
|
464 |
|
|
be marked. */
|
465 |
|
|
|
466 |
|
|
static tree
|
467 |
|
|
mark_type (tree type, enum escape_t escape_status)
|
468 |
|
|
{
|
469 |
|
|
bitmap map = NULL;
|
470 |
|
|
int uid;
|
471 |
|
|
|
472 |
|
|
type = get_canon_type (type, true, true);
|
473 |
|
|
if (!type)
|
474 |
|
|
return NULL;
|
475 |
|
|
|
476 |
|
|
switch (escape_status)
|
477 |
|
|
{
|
478 |
|
|
case EXPOSED_PARAMETER:
|
479 |
|
|
map = global_types_exposed_parameter;
|
480 |
|
|
break;
|
481 |
|
|
case FULL_ESCAPE:
|
482 |
|
|
map = global_types_full_escape;
|
483 |
|
|
break;
|
484 |
|
|
}
|
485 |
|
|
|
486 |
|
|
uid = TYPE_UID (type);
|
487 |
|
|
if (bitmap_bit_p (map, uid))
|
488 |
|
|
return type;
|
489 |
|
|
else
|
490 |
|
|
{
|
491 |
|
|
bitmap_set_bit (map, uid);
|
492 |
|
|
if (escape_status == FULL_ESCAPE)
|
493 |
|
|
{
|
494 |
|
|
/* Efficiency hack. When things are bad, do not mess around
|
495 |
|
|
with this type anymore. */
|
496 |
|
|
bitmap_set_bit (global_types_exposed_parameter, uid);
|
497 |
|
|
}
|
498 |
|
|
}
|
499 |
|
|
return type;
|
500 |
|
|
}
|
501 |
|
|
|
502 |
|
|
/* Add interesting TYPE to the suspect type set. If the set is
|
503 |
|
|
EXPOSED_PARAMETER and the TYPE is a pointer type, the set is
|
504 |
|
|
changed to FULL_ESCAPE. */
|
505 |
|
|
|
506 |
|
|
static void
|
507 |
|
|
mark_interesting_type (tree type, enum escape_t escape_status)
|
508 |
|
|
{
|
509 |
|
|
if (!type) return;
|
510 |
|
|
if (ipa_type_escape_star_count_of_interesting_type (type) >= 0)
|
511 |
|
|
{
|
512 |
|
|
if ((escape_status == EXPOSED_PARAMETER)
|
513 |
|
|
&& POINTER_TYPE_P (type))
|
514 |
|
|
/* EXPOSED_PARAMETERs are only structs or unions are passed by
|
515 |
|
|
value. Anything passed by reference to an external
|
516 |
|
|
function fully exposes the type. */
|
517 |
|
|
mark_type (type, FULL_ESCAPE);
|
518 |
|
|
else
|
519 |
|
|
mark_type (type, escape_status);
|
520 |
|
|
}
|
521 |
|
|
}
|
522 |
|
|
|
523 |
|
|
/* Return true if PARENT is supertype of CHILD. Both types must be
|
524 |
|
|
known to be structures or unions. */
|
525 |
|
|
|
526 |
|
|
static bool
|
527 |
|
|
parent_type_p (tree parent, tree child)
|
528 |
|
|
{
|
529 |
|
|
int i;
|
530 |
|
|
tree binfo, base_binfo;
|
531 |
|
|
if (TYPE_BINFO (parent))
|
532 |
|
|
for (binfo = TYPE_BINFO (parent), i = 0;
|
533 |
|
|
BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
|
534 |
|
|
{
|
535 |
|
|
tree binfotype = BINFO_TYPE (base_binfo);
|
536 |
|
|
if (binfotype == child)
|
537 |
|
|
return true;
|
538 |
|
|
else if (parent_type_p (binfotype, child))
|
539 |
|
|
return true;
|
540 |
|
|
}
|
541 |
|
|
if (TREE_CODE (parent) == UNION_TYPE
|
542 |
|
|
|| TREE_CODE (parent) == QUAL_UNION_TYPE)
|
543 |
|
|
{
|
544 |
|
|
tree field;
|
545 |
|
|
/* Search all of the variants in the union to see if one of them
|
546 |
|
|
is the child. */
|
547 |
|
|
for (field = TYPE_FIELDS (parent);
|
548 |
|
|
field;
|
549 |
|
|
field = TREE_CHAIN (field))
|
550 |
|
|
{
|
551 |
|
|
tree field_type;
|
552 |
|
|
if (TREE_CODE (field) != FIELD_DECL)
|
553 |
|
|
continue;
|
554 |
|
|
|
555 |
|
|
field_type = TREE_TYPE (field);
|
556 |
|
|
if (field_type == child)
|
557 |
|
|
return true;
|
558 |
|
|
}
|
559 |
|
|
|
560 |
|
|
/* If we did not find it, recursively ask the variants if one of
|
561 |
|
|
their children is the child type. */
|
562 |
|
|
for (field = TYPE_FIELDS (parent);
|
563 |
|
|
field;
|
564 |
|
|
field = TREE_CHAIN (field))
|
565 |
|
|
{
|
566 |
|
|
tree field_type;
|
567 |
|
|
if (TREE_CODE (field) != FIELD_DECL)
|
568 |
|
|
continue;
|
569 |
|
|
|
570 |
|
|
field_type = TREE_TYPE (field);
|
571 |
|
|
if (TREE_CODE (field_type) == RECORD_TYPE
|
572 |
|
|
|| TREE_CODE (field_type) == QUAL_UNION_TYPE
|
573 |
|
|
|| TREE_CODE (field_type) == UNION_TYPE)
|
574 |
|
|
if (parent_type_p (field_type, child))
|
575 |
|
|
return true;
|
576 |
|
|
}
|
577 |
|
|
}
|
578 |
|
|
|
579 |
|
|
if (TREE_CODE (parent) == RECORD_TYPE)
|
580 |
|
|
{
|
581 |
|
|
tree field;
|
582 |
|
|
for (field = TYPE_FIELDS (parent);
|
583 |
|
|
field;
|
584 |
|
|
field = TREE_CHAIN (field))
|
585 |
|
|
{
|
586 |
|
|
tree field_type;
|
587 |
|
|
if (TREE_CODE (field) != FIELD_DECL)
|
588 |
|
|
continue;
|
589 |
|
|
|
590 |
|
|
field_type = TREE_TYPE (field);
|
591 |
|
|
if (field_type == child)
|
592 |
|
|
return true;
|
593 |
|
|
/* You can only cast to the first field so if it does not
|
594 |
|
|
match, quit. */
|
595 |
|
|
if (TREE_CODE (field_type) == RECORD_TYPE
|
596 |
|
|
|| TREE_CODE (field_type) == QUAL_UNION_TYPE
|
597 |
|
|
|| TREE_CODE (field_type) == UNION_TYPE)
|
598 |
|
|
{
|
599 |
|
|
if (parent_type_p (field_type, child))
|
600 |
|
|
return true;
|
601 |
|
|
else
|
602 |
|
|
break;
|
603 |
|
|
}
|
604 |
|
|
}
|
605 |
|
|
}
|
606 |
|
|
return false;
|
607 |
|
|
}
|
608 |
|
|
|
609 |
|
|
/* Return the number of pointer tos for TYPE and return TYPE with all
|
610 |
|
|
of these stripped off. */
|
611 |
|
|
|
612 |
|
|
static int
|
613 |
|
|
count_stars (tree* type_ptr)
|
614 |
|
|
{
|
615 |
|
|
tree type = *type_ptr;
|
616 |
|
|
int i = 0;
|
617 |
|
|
type = TYPE_MAIN_VARIANT (type);
|
618 |
|
|
while (POINTER_TYPE_P (type))
|
619 |
|
|
{
|
620 |
|
|
type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
|
621 |
|
|
i++;
|
622 |
|
|
}
|
623 |
|
|
|
624 |
|
|
*type_ptr = type;
|
625 |
|
|
return i;
|
626 |
|
|
}
|
627 |
|
|
|
628 |
|
|
enum cast_type {
|
629 |
|
|
CT_UP = 0x1,
|
630 |
|
|
CT_DOWN = 0x2,
|
631 |
|
|
CT_SIDEWAYS = 0x4,
|
632 |
|
|
CT_USELESS = 0x8,
|
633 |
|
|
CT_FROM_P_BAD = 0x10,
|
634 |
|
|
CT_FROM_NON_P = 0x20,
|
635 |
|
|
CT_TO_NON_INTER = 0x40,
|
636 |
|
|
CT_FROM_MALLOC = 0x80,
|
637 |
|
|
CT_NO_CAST = 0x100
|
638 |
|
|
};
|
639 |
|
|
|
640 |
|
|
/* Check the cast FROM_TYPE to TO_TYPE. This function requires that
|
641 |
|
|
the two types have already passed the
|
642 |
|
|
ipa_type_escape_star_count_of_interesting_type test. */
|
643 |
|
|
|
644 |
|
|
static enum cast_type
|
645 |
|
|
check_cast_type (tree to_type, tree from_type)
|
646 |
|
|
{
|
647 |
|
|
int to_stars = count_stars (&to_type);
|
648 |
|
|
int from_stars = count_stars (&from_type);
|
649 |
|
|
if (to_stars != from_stars)
|
650 |
|
|
return CT_SIDEWAYS;
|
651 |
|
|
|
652 |
|
|
if (to_type == from_type)
|
653 |
|
|
return CT_USELESS;
|
654 |
|
|
|
655 |
|
|
if (parent_type_p (to_type, from_type)) return CT_UP;
|
656 |
|
|
if (parent_type_p (from_type, to_type)) return CT_DOWN;
|
657 |
|
|
return CT_SIDEWAYS;
|
658 |
|
|
}
|
659 |
|
|
|
660 |
|
|
/* This function returns nonzero if VAR is result of call
|
661 |
|
|
to malloc function. */
|
662 |
|
|
|
663 |
|
|
static bool
|
664 |
|
|
is_malloc_result (tree var)
|
665 |
|
|
{
|
666 |
|
|
gimple def_stmt;
|
667 |
|
|
|
668 |
|
|
if (!var)
|
669 |
|
|
return false;
|
670 |
|
|
|
671 |
|
|
if (SSA_NAME_IS_DEFAULT_DEF (var))
|
672 |
|
|
return false;
|
673 |
|
|
|
674 |
|
|
def_stmt = SSA_NAME_DEF_STMT (var);
|
675 |
|
|
|
676 |
|
|
if (!is_gimple_call (def_stmt))
|
677 |
|
|
return false;
|
678 |
|
|
|
679 |
|
|
if (var != gimple_call_lhs (def_stmt))
|
680 |
|
|
return false;
|
681 |
|
|
|
682 |
|
|
return ((gimple_call_flags (def_stmt) & ECF_MALLOC) != 0);
|
683 |
|
|
|
684 |
|
|
}
|
685 |
|
|
|
686 |
|
|
/* Check a cast FROM this variable, TO_TYPE. Mark the escaping types
|
687 |
|
|
if appropriate. Returns cast_type as detected. */
|
688 |
|
|
|
689 |
|
|
static enum cast_type
|
690 |
|
|
check_cast (tree to_type, tree from)
|
691 |
|
|
{
|
692 |
|
|
tree from_type = get_canon_type (TREE_TYPE (from), false, false);
|
693 |
|
|
bool to_interesting_type, from_interesting_type;
|
694 |
|
|
enum cast_type cast = CT_NO_CAST;
|
695 |
|
|
|
696 |
|
|
to_type = get_canon_type (to_type, false, false);
|
697 |
|
|
if (!from_type || !to_type || from_type == to_type)
|
698 |
|
|
return cast;
|
699 |
|
|
|
700 |
|
|
to_interesting_type =
|
701 |
|
|
ipa_type_escape_star_count_of_interesting_type (to_type) >= 0;
|
702 |
|
|
from_interesting_type =
|
703 |
|
|
ipa_type_escape_star_count_of_interesting_type (from_type) >= 0;
|
704 |
|
|
|
705 |
|
|
if (to_interesting_type)
|
706 |
|
|
if (from_interesting_type)
|
707 |
|
|
{
|
708 |
|
|
/* Both types are interesting. This can be one of four types
|
709 |
|
|
of cast: useless, up, down, or sideways. We do not care
|
710 |
|
|
about up or useless. Sideways casts are always bad and
|
711 |
|
|
both sides get marked as escaping. Downcasts are not
|
712 |
|
|
interesting here because if type is marked as escaping, all
|
713 |
|
|
of its subtypes escape. */
|
714 |
|
|
cast = check_cast_type (to_type, from_type);
|
715 |
|
|
switch (cast)
|
716 |
|
|
{
|
717 |
|
|
case CT_UP:
|
718 |
|
|
case CT_USELESS:
|
719 |
|
|
case CT_DOWN:
|
720 |
|
|
break;
|
721 |
|
|
|
722 |
|
|
case CT_SIDEWAYS:
|
723 |
|
|
mark_type (to_type, FULL_ESCAPE);
|
724 |
|
|
mark_type (from_type, FULL_ESCAPE);
|
725 |
|
|
break;
|
726 |
|
|
|
727 |
|
|
default:
|
728 |
|
|
break;
|
729 |
|
|
}
|
730 |
|
|
}
|
731 |
|
|
else
|
732 |
|
|
{
|
733 |
|
|
/* This code excludes two cases from marking as escaped:
|
734 |
|
|
|
735 |
|
|
1. if this is a cast of index of array of structures/unions
|
736 |
|
|
that happens before accessing array element, we should not
|
737 |
|
|
mark it as escaped.
|
738 |
|
|
2. if this is a cast from the local that is a result from a
|
739 |
|
|
call to malloc, do not mark the cast as bad.
|
740 |
|
|
|
741 |
|
|
*/
|
742 |
|
|
|
743 |
|
|
if (POINTER_TYPE_P (to_type) && !POINTER_TYPE_P (from_type))
|
744 |
|
|
cast = CT_FROM_NON_P;
|
745 |
|
|
else if (TREE_CODE (from) == SSA_NAME
|
746 |
|
|
&& is_malloc_result (from))
|
747 |
|
|
cast = CT_FROM_MALLOC;
|
748 |
|
|
else
|
749 |
|
|
{
|
750 |
|
|
cast = CT_FROM_P_BAD;
|
751 |
|
|
mark_type (to_type, FULL_ESCAPE);
|
752 |
|
|
}
|
753 |
|
|
}
|
754 |
|
|
else if (from_interesting_type)
|
755 |
|
|
{
|
756 |
|
|
mark_type (from_type, FULL_ESCAPE);
|
757 |
|
|
cast = CT_TO_NON_INTER;
|
758 |
|
|
}
|
759 |
|
|
|
760 |
|
|
return cast;
|
761 |
|
|
}
|
762 |
|
|
|
763 |
|
|
|
764 |
|
|
/* Scan assignment statement S to see if there are any casts within it. */
|
765 |
|
|
|
766 |
|
|
static unsigned int
|
767 |
|
|
look_for_casts_stmt (gimple s)
|
768 |
|
|
{
|
769 |
|
|
unsigned int cast = 0;
|
770 |
|
|
|
771 |
|
|
gcc_assert (is_gimple_assign (s));
|
772 |
|
|
|
773 |
|
|
if (gimple_assign_cast_p (s))
|
774 |
|
|
{
|
775 |
|
|
tree castfromvar = gimple_assign_rhs1 (s);
|
776 |
|
|
cast |= check_cast (TREE_TYPE (gimple_assign_lhs (s)), castfromvar);
|
777 |
|
|
}
|
778 |
|
|
else
|
779 |
|
|
{
|
780 |
|
|
size_t i;
|
781 |
|
|
for (i = 0; i < gimple_num_ops (s); i++)
|
782 |
|
|
cast |= look_for_casts (gimple_op (s, i));
|
783 |
|
|
}
|
784 |
|
|
|
785 |
|
|
if (!cast)
|
786 |
|
|
cast = CT_NO_CAST;
|
787 |
|
|
|
788 |
|
|
return cast;
|
789 |
|
|
}
|
790 |
|
|
|
791 |
|
|
|
792 |
|
|
typedef struct cast
|
793 |
|
|
{
|
794 |
|
|
int type;
|
795 |
|
|
gimple stmt;
|
796 |
|
|
} cast_t;
|
797 |
|
|
|
798 |
|
|
/* This function is a callback for walk_use_def_chains function called
|
799 |
|
|
from is_array_access_through_pointer_and_index. */
|
800 |
|
|
|
801 |
|
|
static bool
|
802 |
|
|
is_cast_from_non_pointer (tree var, gimple def_stmt, void *data)
|
803 |
|
|
{
|
804 |
|
|
if (!def_stmt || !var)
|
805 |
|
|
return false;
|
806 |
|
|
|
807 |
|
|
if (gimple_code (def_stmt) == GIMPLE_PHI)
|
808 |
|
|
return false;
|
809 |
|
|
|
810 |
|
|
if (SSA_NAME_IS_DEFAULT_DEF (var))
|
811 |
|
|
return false;
|
812 |
|
|
|
813 |
|
|
if (is_gimple_assign (def_stmt))
|
814 |
|
|
{
|
815 |
|
|
use_operand_p use_p;
|
816 |
|
|
ssa_op_iter iter;
|
817 |
|
|
unsigned int cast = look_for_casts_stmt (def_stmt);
|
818 |
|
|
|
819 |
|
|
/* Check that only one cast happened, and it's of non-pointer
|
820 |
|
|
type. */
|
821 |
|
|
if ((cast & CT_FROM_NON_P) == (CT_FROM_NON_P)
|
822 |
|
|
&& (cast & ~(CT_FROM_NON_P)) == 0)
|
823 |
|
|
{
|
824 |
|
|
((cast_t *)data)->stmt = def_stmt;
|
825 |
|
|
((cast_t *)data)->type++;
|
826 |
|
|
|
827 |
|
|
FOR_EACH_SSA_USE_OPERAND (use_p, def_stmt, iter, SSA_OP_ALL_USES)
|
828 |
|
|
{
|
829 |
|
|
walk_use_def_chains (USE_FROM_PTR (use_p),
|
830 |
|
|
is_cast_from_non_pointer, data, false);
|
831 |
|
|
if (((cast_t*)data)->type == -1)
|
832 |
|
|
break;
|
833 |
|
|
}
|
834 |
|
|
}
|
835 |
|
|
/* Check that there is no cast, or cast is not harmful. */
|
836 |
|
|
else if ((cast & CT_NO_CAST) == (CT_NO_CAST)
|
837 |
|
|
|| (cast & CT_DOWN) == (CT_DOWN)
|
838 |
|
|
|| (cast & CT_UP) == (CT_UP)
|
839 |
|
|
|| (cast & CT_USELESS) == (CT_USELESS)
|
840 |
|
|
|| (cast & CT_FROM_MALLOC) == (CT_FROM_MALLOC))
|
841 |
|
|
{
|
842 |
|
|
FOR_EACH_SSA_USE_OPERAND (use_p, def_stmt, iter, SSA_OP_ALL_USES)
|
843 |
|
|
{
|
844 |
|
|
walk_use_def_chains (USE_FROM_PTR (use_p),
|
845 |
|
|
is_cast_from_non_pointer, data, false);
|
846 |
|
|
if (((cast_t*)data)->type == -1)
|
847 |
|
|
break;
|
848 |
|
|
}
|
849 |
|
|
}
|
850 |
|
|
/* The cast is harmful. */
|
851 |
|
|
else
|
852 |
|
|
((cast_t *)data)->type = -1;
|
853 |
|
|
}
|
854 |
|
|
|
855 |
|
|
if (((cast_t*)data)->type == -1)
|
856 |
|
|
return true;
|
857 |
|
|
|
858 |
|
|
return false;
|
859 |
|
|
}
|
860 |
|
|
|
861 |
|
|
/* When array element a_p[i] is accessed through the pointer a_p
|
862 |
|
|
and index i, it's translated into the following sequence
|
863 |
|
|
in gimple:
|
864 |
|
|
|
865 |
|
|
i.1_5 = (unsigned int) i_1;
|
866 |
|
|
D.1605_6 = i.1_5 * 16;
|
867 |
|
|
D.1606_7 = (struct str_t *) D.1605_6;
|
868 |
|
|
a_p.2_8 = a_p;
|
869 |
|
|
D.1608_9 = D.1606_7 + a_p.2_8;
|
870 |
|
|
|
871 |
|
|
OP0 and OP1 are of the same pointer types and stand for
|
872 |
|
|
D.1606_7 and a_p.2_8 or vise versa.
|
873 |
|
|
|
874 |
|
|
This function checks that:
|
875 |
|
|
|
876 |
|
|
1. one of OP0 and OP1 (D.1606_7) has passed only one cast from
|
877 |
|
|
non-pointer type (D.1606_7 = (struct str_t *) D.1605_6;).
|
878 |
|
|
|
879 |
|
|
2. one of OP0 and OP1 which has passed the cast from
|
880 |
|
|
non-pointer type (D.1606_7), is actually generated by multiplication of
|
881 |
|
|
index by size of type to which both OP0 and OP1 point to
|
882 |
|
|
(in this case D.1605_6 = i.1_5 * 16; ).
|
883 |
|
|
|
884 |
|
|
3. an address of def of the var to which was made cast (D.1605_6)
|
885 |
|
|
was not taken.(How can it happen?)
|
886 |
|
|
|
887 |
|
|
The following items are checked implicitly by the end of algorithm:
|
888 |
|
|
|
889 |
|
|
4. one of OP0 and OP1 (a_p.2_8) have never been cast
|
890 |
|
|
(because if it was cast to pointer type, its type, that is also
|
891 |
|
|
the type of OP0 and OP1, will be marked as escaped during
|
892 |
|
|
analysis of casting stmt (when check_cast() is called
|
893 |
|
|
from scan_for_refs for this stmt)).
|
894 |
|
|
|
895 |
|
|
5. defs of OP0 and OP1 are not passed into externally visible function
|
896 |
|
|
(because if they are passed then their type, that is also the type of OP0
|
897 |
|
|
and OP1, will be marked and escaped during check_call function called from
|
898 |
|
|
scan_for_refs with call stmt).
|
899 |
|
|
|
900 |
|
|
In total, 1-5 guaranty that it's an access to array by pointer and index.
|
901 |
|
|
|
902 |
|
|
*/
|
903 |
|
|
|
904 |
|
|
bool
|
905 |
|
|
is_array_access_through_pointer_and_index (enum tree_code code, tree op0,
|
906 |
|
|
tree op1, tree *base, tree *offset,
|
907 |
|
|
gimple *offset_cast_stmt)
|
908 |
|
|
{
|
909 |
|
|
tree before_cast;
|
910 |
|
|
gimple before_cast_def_stmt;
|
911 |
|
|
cast_t op0_cast, op1_cast;
|
912 |
|
|
|
913 |
|
|
*base = NULL;
|
914 |
|
|
*offset = NULL;
|
915 |
|
|
*offset_cast_stmt = NULL;
|
916 |
|
|
|
917 |
|
|
/* Check 1. */
|
918 |
|
|
if (code == POINTER_PLUS_EXPR)
|
919 |
|
|
{
|
920 |
|
|
tree op0type = TYPE_MAIN_VARIANT (TREE_TYPE (op0));
|
921 |
|
|
tree op1type = TYPE_MAIN_VARIANT (TREE_TYPE (op1));
|
922 |
|
|
|
923 |
|
|
/* One of op0 and op1 is of pointer type and the other is numerical. */
|
924 |
|
|
if (POINTER_TYPE_P (op0type) && NUMERICAL_TYPE_CHECK (op1type))
|
925 |
|
|
{
|
926 |
|
|
*base = op0;
|
927 |
|
|
*offset = op1;
|
928 |
|
|
}
|
929 |
|
|
else if (POINTER_TYPE_P (op1type) && NUMERICAL_TYPE_CHECK (op0type))
|
930 |
|
|
{
|
931 |
|
|
*base = op1;
|
932 |
|
|
*offset = op0;
|
933 |
|
|
}
|
934 |
|
|
else
|
935 |
|
|
return false;
|
936 |
|
|
}
|
937 |
|
|
else
|
938 |
|
|
{
|
939 |
|
|
/* Init data for walk_use_def_chains function. */
|
940 |
|
|
op0_cast.type = op1_cast.type = 0;
|
941 |
|
|
op0_cast.stmt = op1_cast.stmt = NULL;
|
942 |
|
|
|
943 |
|
|
visited_stmts = pointer_set_create ();
|
944 |
|
|
walk_use_def_chains (op0, is_cast_from_non_pointer,(void *)(&op0_cast),
|
945 |
|
|
false);
|
946 |
|
|
pointer_set_destroy (visited_stmts);
|
947 |
|
|
|
948 |
|
|
visited_stmts = pointer_set_create ();
|
949 |
|
|
walk_use_def_chains (op1, is_cast_from_non_pointer,(void *)(&op1_cast),
|
950 |
|
|
false);
|
951 |
|
|
pointer_set_destroy (visited_stmts);
|
952 |
|
|
|
953 |
|
|
if (op0_cast.type == 1 && op1_cast.type == 0)
|
954 |
|
|
{
|
955 |
|
|
*base = op1;
|
956 |
|
|
*offset = op0;
|
957 |
|
|
*offset_cast_stmt = op0_cast.stmt;
|
958 |
|
|
}
|
959 |
|
|
else if (op0_cast.type == 0 && op1_cast.type == 1)
|
960 |
|
|
{
|
961 |
|
|
*base = op0;
|
962 |
|
|
*offset = op1;
|
963 |
|
|
*offset_cast_stmt = op1_cast.stmt;
|
964 |
|
|
}
|
965 |
|
|
else
|
966 |
|
|
return false;
|
967 |
|
|
}
|
968 |
|
|
|
969 |
|
|
/* Check 2.
|
970 |
|
|
offset_cast_stmt is of the form:
|
971 |
|
|
D.1606_7 = (struct str_t *) D.1605_6; */
|
972 |
|
|
|
973 |
|
|
if (*offset_cast_stmt)
|
974 |
|
|
{
|
975 |
|
|
before_cast = SINGLE_SSA_TREE_OPERAND (*offset_cast_stmt, SSA_OP_USE);
|
976 |
|
|
if (!before_cast)
|
977 |
|
|
return false;
|
978 |
|
|
|
979 |
|
|
if (SSA_NAME_IS_DEFAULT_DEF (before_cast))
|
980 |
|
|
return false;
|
981 |
|
|
|
982 |
|
|
before_cast_def_stmt = SSA_NAME_DEF_STMT (before_cast);
|
983 |
|
|
if (!before_cast_def_stmt)
|
984 |
|
|
return false;
|
985 |
|
|
}
|
986 |
|
|
else
|
987 |
|
|
before_cast_def_stmt = SSA_NAME_DEF_STMT (*offset);
|
988 |
|
|
|
989 |
|
|
/* before_cast_def_stmt should be of the form:
|
990 |
|
|
D.1605_6 = i.1_5 * 16; */
|
991 |
|
|
|
992 |
|
|
if (is_gimple_assign (before_cast_def_stmt))
|
993 |
|
|
{
|
994 |
|
|
/* We expect temporary here. */
|
995 |
|
|
if (!is_gimple_reg (gimple_assign_lhs (before_cast_def_stmt)))
|
996 |
|
|
return false;
|
997 |
|
|
|
998 |
|
|
if (gimple_assign_rhs_code (before_cast_def_stmt) == MULT_EXPR)
|
999 |
|
|
{
|
1000 |
|
|
tree arg0 = gimple_assign_rhs1 (before_cast_def_stmt);
|
1001 |
|
|
tree arg1 = gimple_assign_rhs2 (before_cast_def_stmt);
|
1002 |
|
|
tree unit_size =
|
1003 |
|
|
TYPE_SIZE_UNIT (TREE_TYPE (TYPE_MAIN_VARIANT (TREE_TYPE (op0))));
|
1004 |
|
|
|
1005 |
|
|
if (!(CONSTANT_CLASS_P (arg0)
|
1006 |
|
|
&& simple_cst_equal (arg0, unit_size))
|
1007 |
|
|
&& !(CONSTANT_CLASS_P (arg1)
|
1008 |
|
|
&& simple_cst_equal (arg1, unit_size)))
|
1009 |
|
|
return false;
|
1010 |
|
|
}
|
1011 |
|
|
else
|
1012 |
|
|
return false;
|
1013 |
|
|
}
|
1014 |
|
|
else
|
1015 |
|
|
return false;
|
1016 |
|
|
|
1017 |
|
|
/* Check 3.
|
1018 |
|
|
check that address of D.1605_6 was not taken.
|
1019 |
|
|
FIXME: if D.1605_6 is gimple reg than it cannot be addressable. */
|
1020 |
|
|
|
1021 |
|
|
return true;
|
1022 |
|
|
}
|
1023 |
|
|
|
1024 |
|
|
/* Register the parameter and return types of function FN. The type
|
1025 |
|
|
ESCAPES if the function is visible outside of the compilation
|
1026 |
|
|
unit. */
|
1027 |
|
|
static void
|
1028 |
|
|
check_function_parameter_and_return_types (tree fn, bool escapes)
|
1029 |
|
|
{
|
1030 |
|
|
tree arg;
|
1031 |
|
|
|
1032 |
|
|
if (TYPE_ARG_TYPES (TREE_TYPE (fn)))
|
1033 |
|
|
{
|
1034 |
|
|
for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
|
1035 |
|
|
arg && TREE_VALUE (arg) != void_type_node;
|
1036 |
|
|
arg = TREE_CHAIN (arg))
|
1037 |
|
|
{
|
1038 |
|
|
tree type = get_canon_type (TREE_VALUE (arg), false, false);
|
1039 |
|
|
if (escapes)
|
1040 |
|
|
mark_interesting_type (type, EXPOSED_PARAMETER);
|
1041 |
|
|
}
|
1042 |
|
|
}
|
1043 |
|
|
else
|
1044 |
|
|
{
|
1045 |
|
|
/* FIXME - According to Geoff Keating, we should never have to
|
1046 |
|
|
do this; the front ends should always process the arg list
|
1047 |
|
|
from the TYPE_ARG_LIST. However, Geoff is wrong, this code
|
1048 |
|
|
does seem to be live. */
|
1049 |
|
|
|
1050 |
|
|
for (arg = DECL_ARGUMENTS (fn); arg; arg = TREE_CHAIN (arg))
|
1051 |
|
|
{
|
1052 |
|
|
tree type = get_canon_type (TREE_TYPE (arg), false, false);
|
1053 |
|
|
if (escapes)
|
1054 |
|
|
mark_interesting_type (type, EXPOSED_PARAMETER);
|
1055 |
|
|
}
|
1056 |
|
|
}
|
1057 |
|
|
if (escapes)
|
1058 |
|
|
{
|
1059 |
|
|
tree type = get_canon_type (TREE_TYPE (TREE_TYPE (fn)), false, false);
|
1060 |
|
|
mark_interesting_type (type, EXPOSED_PARAMETER);
|
1061 |
|
|
}
|
1062 |
|
|
}
|
1063 |
|
|
|
1064 |
|
|
/* Return true if the variable T is the right kind of static variable to
|
1065 |
|
|
perform compilation unit scope escape analysis. */
|
1066 |
|
|
|
1067 |
|
|
static inline void
|
1068 |
|
|
has_proper_scope_for_analysis (tree t)
|
1069 |
|
|
{
|
1070 |
|
|
/* If the variable has the "used" attribute, treat it as if it had a
|
1071 |
|
|
been touched by the devil. */
|
1072 |
|
|
tree type = get_canon_type (TREE_TYPE (t), false, false);
|
1073 |
|
|
if (!type) return;
|
1074 |
|
|
|
1075 |
|
|
if (DECL_PRESERVE_P (t))
|
1076 |
|
|
{
|
1077 |
|
|
mark_interesting_type (type, FULL_ESCAPE);
|
1078 |
|
|
return;
|
1079 |
|
|
}
|
1080 |
|
|
|
1081 |
|
|
/* Do not want to do anything with volatile except mark any
|
1082 |
|
|
function that uses one to be not const or pure. */
|
1083 |
|
|
if (TREE_THIS_VOLATILE (t))
|
1084 |
|
|
return;
|
1085 |
|
|
|
1086 |
|
|
/* Do not care about a local automatic that is not static. */
|
1087 |
|
|
if (!TREE_STATIC (t) && !DECL_EXTERNAL (t))
|
1088 |
|
|
return;
|
1089 |
|
|
|
1090 |
|
|
if (DECL_EXTERNAL (t) || TREE_PUBLIC (t))
|
1091 |
|
|
{
|
1092 |
|
|
/* If the front end set the variable to be READONLY and
|
1093 |
|
|
constant, we can allow this variable in pure or const
|
1094 |
|
|
functions but the scope is too large for our analysis to set
|
1095 |
|
|
these bits ourselves. */
|
1096 |
|
|
|
1097 |
|
|
if (TREE_READONLY (t)
|
1098 |
|
|
&& DECL_INITIAL (t)
|
1099 |
|
|
&& is_gimple_min_invariant (DECL_INITIAL (t)))
|
1100 |
|
|
; /* Read of a constant, do not change the function state. */
|
1101 |
|
|
else
|
1102 |
|
|
{
|
1103 |
|
|
/* The type escapes for all public and externs. */
|
1104 |
|
|
mark_interesting_type (type, FULL_ESCAPE);
|
1105 |
|
|
}
|
1106 |
|
|
}
|
1107 |
|
|
}
|
1108 |
|
|
|
1109 |
|
|
/* If T is a VAR_DECL for a static that we are interested in, add the
|
1110 |
|
|
uid to the bitmap. */
|
1111 |
|
|
|
1112 |
|
|
static void
|
1113 |
|
|
check_operand (tree t)
|
1114 |
|
|
{
|
1115 |
|
|
if (!t) return;
|
1116 |
|
|
|
1117 |
|
|
/* This is an assignment from a function, register the types as
|
1118 |
|
|
escaping. */
|
1119 |
|
|
if (TREE_CODE (t) == FUNCTION_DECL)
|
1120 |
|
|
check_function_parameter_and_return_types (t, true);
|
1121 |
|
|
|
1122 |
|
|
else if (TREE_CODE (t) == VAR_DECL)
|
1123 |
|
|
has_proper_scope_for_analysis (t);
|
1124 |
|
|
}
|
1125 |
|
|
|
1126 |
|
|
/* Examine tree T for references. */
|
1127 |
|
|
|
1128 |
|
|
static void
|
1129 |
|
|
check_tree (tree t)
|
1130 |
|
|
{
|
1131 |
|
|
/* We want to catch here also REALPART_EXPR and IMAGEPART_EXPR,
|
1132 |
|
|
but they already included in handled_component_p. */
|
1133 |
|
|
while (handled_component_p (t))
|
1134 |
|
|
{
|
1135 |
|
|
if (TREE_CODE (t) == ARRAY_REF)
|
1136 |
|
|
check_operand (TREE_OPERAND (t, 1));
|
1137 |
|
|
t = TREE_OPERAND (t, 0);
|
1138 |
|
|
}
|
1139 |
|
|
|
1140 |
|
|
if (INDIRECT_REF_P (t))
|
1141 |
|
|
/* || TREE_CODE (t) == MEM_REF) */
|
1142 |
|
|
check_tree (TREE_OPERAND (t, 0));
|
1143 |
|
|
|
1144 |
|
|
if (SSA_VAR_P (t) || (TREE_CODE (t) == FUNCTION_DECL))
|
1145 |
|
|
{
|
1146 |
|
|
check_operand (t);
|
1147 |
|
|
if (DECL_P (t) && DECL_INITIAL (t))
|
1148 |
|
|
check_tree (DECL_INITIAL (t));
|
1149 |
|
|
}
|
1150 |
|
|
}
|
1151 |
|
|
|
1152 |
|
|
/* Create an address_of edge FROM_TYPE.TO_TYPE. */
|
1153 |
|
|
static void
|
1154 |
|
|
mark_interesting_addressof (tree to_type, tree from_type)
|
1155 |
|
|
{
|
1156 |
|
|
int from_uid;
|
1157 |
|
|
int to_uid;
|
1158 |
|
|
bitmap type_map;
|
1159 |
|
|
splay_tree_node result;
|
1160 |
|
|
|
1161 |
|
|
from_type = get_canon_type (from_type, false, false);
|
1162 |
|
|
to_type = get_canon_type (to_type, false, false);
|
1163 |
|
|
|
1164 |
|
|
if (!from_type || !to_type)
|
1165 |
|
|
return;
|
1166 |
|
|
|
1167 |
|
|
from_uid = TYPE_UID (from_type);
|
1168 |
|
|
to_uid = TYPE_UID (to_type);
|
1169 |
|
|
|
1170 |
|
|
gcc_assert (ipa_type_escape_star_count_of_interesting_type (from_type) == 0);
|
1171 |
|
|
|
1172 |
|
|
/* Process the Y into X map pointer. */
|
1173 |
|
|
result = splay_tree_lookup (uid_to_addressof_down_map,
|
1174 |
|
|
(splay_tree_key) from_uid);
|
1175 |
|
|
|
1176 |
|
|
if (result)
|
1177 |
|
|
type_map = (bitmap) result->value;
|
1178 |
|
|
else
|
1179 |
|
|
{
|
1180 |
|
|
type_map = BITMAP_ALLOC (&ipa_obstack);
|
1181 |
|
|
splay_tree_insert (uid_to_addressof_down_map,
|
1182 |
|
|
from_uid,
|
1183 |
|
|
(splay_tree_value)type_map);
|
1184 |
|
|
}
|
1185 |
|
|
bitmap_set_bit (type_map, TYPE_UID (to_type));
|
1186 |
|
|
|
1187 |
|
|
/* Process the X into Y reverse map pointer. */
|
1188 |
|
|
result =
|
1189 |
|
|
splay_tree_lookup (uid_to_addressof_up_map, (splay_tree_key) to_uid);
|
1190 |
|
|
|
1191 |
|
|
if (result)
|
1192 |
|
|
type_map = (bitmap) result->value;
|
1193 |
|
|
else
|
1194 |
|
|
{
|
1195 |
|
|
type_map = BITMAP_ALLOC (&ipa_obstack);
|
1196 |
|
|
splay_tree_insert (uid_to_addressof_up_map,
|
1197 |
|
|
to_uid,
|
1198 |
|
|
(splay_tree_value)type_map);
|
1199 |
|
|
}
|
1200 |
|
|
bitmap_set_bit (type_map, TYPE_UID (from_type));
|
1201 |
|
|
}
|
1202 |
|
|
|
1203 |
|
|
/* Scan tree T to see if there are any addresses taken in within T. */
|
1204 |
|
|
|
1205 |
|
|
static void
|
1206 |
|
|
look_for_address_of (tree t)
|
1207 |
|
|
{
|
1208 |
|
|
if (TREE_CODE (t) == ADDR_EXPR)
|
1209 |
|
|
{
|
1210 |
|
|
tree x = get_base_var (t);
|
1211 |
|
|
tree cref = TREE_OPERAND (t, 0);
|
1212 |
|
|
|
1213 |
|
|
/* If we have an expression of the form "&a.b.c.d", mark a.b,
|
1214 |
|
|
b.c and c.d. as having its address taken. */
|
1215 |
|
|
tree fielddecl = NULL_TREE;
|
1216 |
|
|
while (cref!= x)
|
1217 |
|
|
{
|
1218 |
|
|
if (TREE_CODE (cref) == COMPONENT_REF)
|
1219 |
|
|
{
|
1220 |
|
|
fielddecl = TREE_OPERAND (cref, 1);
|
1221 |
|
|
mark_interesting_addressof (TREE_TYPE (fielddecl),
|
1222 |
|
|
DECL_FIELD_CONTEXT (fielddecl));
|
1223 |
|
|
}
|
1224 |
|
|
else if (TREE_CODE (cref) == ARRAY_REF)
|
1225 |
|
|
get_canon_type (TREE_TYPE (cref), false, false);
|
1226 |
|
|
|
1227 |
|
|
cref = TREE_OPERAND (cref, 0);
|
1228 |
|
|
}
|
1229 |
|
|
|
1230 |
|
|
if (TREE_CODE (x) == VAR_DECL)
|
1231 |
|
|
has_proper_scope_for_analysis (x);
|
1232 |
|
|
}
|
1233 |
|
|
}
|
1234 |
|
|
|
1235 |
|
|
|
1236 |
|
|
/* Scan tree T to see if there are any casts within it. */
|
1237 |
|
|
|
1238 |
|
|
static unsigned int
|
1239 |
|
|
look_for_casts (tree t)
|
1240 |
|
|
{
|
1241 |
|
|
unsigned int cast = 0;
|
1242 |
|
|
|
1243 |
|
|
if (is_gimple_cast (t) || TREE_CODE (t) == VIEW_CONVERT_EXPR)
|
1244 |
|
|
{
|
1245 |
|
|
tree castfromvar = TREE_OPERAND (t, 0);
|
1246 |
|
|
cast = cast | check_cast (TREE_TYPE (t), castfromvar);
|
1247 |
|
|
}
|
1248 |
|
|
else
|
1249 |
|
|
while (handled_component_p (t))
|
1250 |
|
|
{
|
1251 |
|
|
t = TREE_OPERAND (t, 0);
|
1252 |
|
|
if (TREE_CODE (t) == VIEW_CONVERT_EXPR)
|
1253 |
|
|
{
|
1254 |
|
|
/* This may be some part of a component ref.
|
1255 |
|
|
IE it may be a.b.VIEW_CONVERT_EXPR<weird_type>(c).d, AFAIK.
|
1256 |
|
|
castfromref will give you a.b.c, not a. */
|
1257 |
|
|
tree castfromref = TREE_OPERAND (t, 0);
|
1258 |
|
|
cast = cast | check_cast (TREE_TYPE (t), castfromref);
|
1259 |
|
|
}
|
1260 |
|
|
else if (TREE_CODE (t) == COMPONENT_REF)
|
1261 |
|
|
get_canon_type (TREE_TYPE (TREE_OPERAND (t, 1)), false, false);
|
1262 |
|
|
}
|
1263 |
|
|
|
1264 |
|
|
if (!cast)
|
1265 |
|
|
cast = CT_NO_CAST;
|
1266 |
|
|
return cast;
|
1267 |
|
|
}
|
1268 |
|
|
|
1269 |
|
|
/* Check to see if T is a read or address of operation on a static var
|
1270 |
|
|
we are interested in analyzing. */
|
1271 |
|
|
|
1272 |
|
|
static void
|
1273 |
|
|
check_rhs_var (tree t)
|
1274 |
|
|
{
|
1275 |
|
|
look_for_address_of (t);
|
1276 |
|
|
check_tree (t);
|
1277 |
|
|
}
|
1278 |
|
|
|
1279 |
|
|
/* Check to see if T is an assignment to a static var we are
|
1280 |
|
|
interested in analyzing. */
|
1281 |
|
|
|
1282 |
|
|
static void
|
1283 |
|
|
check_lhs_var (tree t)
|
1284 |
|
|
{
|
1285 |
|
|
check_tree (t);
|
1286 |
|
|
}
|
1287 |
|
|
|
1288 |
|
|
/* This is a scaled down version of get_asm_expr_operands from
|
1289 |
|
|
tree_ssa_operands.c. The version there runs much later and assumes
|
1290 |
|
|
that aliasing information is already available. Here we are just
|
1291 |
|
|
trying to find if the set of inputs and outputs contain references
|
1292 |
|
|
or address of operations to local. FN is the function being
|
1293 |
|
|
analyzed and STMT is the actual asm statement. */
|
1294 |
|
|
|
1295 |
|
|
static void
|
1296 |
|
|
check_asm (gimple stmt)
|
1297 |
|
|
{
|
1298 |
|
|
size_t i;
|
1299 |
|
|
|
1300 |
|
|
for (i = 0; i < gimple_asm_noutputs (stmt); i++)
|
1301 |
|
|
check_lhs_var (gimple_asm_output_op (stmt, i));
|
1302 |
|
|
|
1303 |
|
|
for (i = 0; i < gimple_asm_ninputs (stmt); i++)
|
1304 |
|
|
check_rhs_var (gimple_asm_input_op (stmt, i));
|
1305 |
|
|
|
1306 |
|
|
/* There is no code here to check for asm memory clobbers. The
|
1307 |
|
|
casual maintainer might think that such code would be necessary,
|
1308 |
|
|
but that appears to be wrong. In other parts of the compiler,
|
1309 |
|
|
the asm memory clobbers are assumed to only clobber variables
|
1310 |
|
|
that are addressable. All types with addressable instances are
|
1311 |
|
|
assumed to already escape. So, we are protected here. */
|
1312 |
|
|
}
|
1313 |
|
|
|
1314 |
|
|
|
1315 |
|
|
/* Check the parameters of function call to CALL to mark the
|
1316 |
|
|
types that pass across the function boundary. Also check to see if
|
1317 |
|
|
this is either an indirect call, a call outside the compilation
|
1318 |
|
|
unit. */
|
1319 |
|
|
|
1320 |
|
|
static void
|
1321 |
|
|
check_call (gimple call)
|
1322 |
|
|
{
|
1323 |
|
|
tree callee_t = gimple_call_fndecl (call);
|
1324 |
|
|
struct cgraph_node* callee;
|
1325 |
|
|
enum availability avail = AVAIL_NOT_AVAILABLE;
|
1326 |
|
|
size_t i;
|
1327 |
|
|
|
1328 |
|
|
for (i = 0; i < gimple_call_num_args (call); i++)
|
1329 |
|
|
check_rhs_var (gimple_call_arg (call, i));
|
1330 |
|
|
|
1331 |
|
|
if (callee_t)
|
1332 |
|
|
{
|
1333 |
|
|
tree arg_type;
|
1334 |
|
|
tree last_arg_type = NULL;
|
1335 |
|
|
callee = cgraph_node(callee_t);
|
1336 |
|
|
avail = cgraph_function_body_availability (callee);
|
1337 |
|
|
|
1338 |
|
|
/* Check that there are no implicit casts in the passing of
|
1339 |
|
|
parameters. */
|
1340 |
|
|
if (TYPE_ARG_TYPES (TREE_TYPE (callee_t)))
|
1341 |
|
|
{
|
1342 |
|
|
for (arg_type = TYPE_ARG_TYPES (TREE_TYPE (callee_t)), i = 0;
|
1343 |
|
|
arg_type && TREE_VALUE (arg_type) != void_type_node
|
1344 |
|
|
&& i < gimple_call_num_args (call);
|
1345 |
|
|
arg_type = TREE_CHAIN (arg_type), i++)
|
1346 |
|
|
{
|
1347 |
|
|
tree operand = gimple_call_arg (call, i);
|
1348 |
|
|
if (operand)
|
1349 |
|
|
{
|
1350 |
|
|
last_arg_type = TREE_VALUE(arg_type);
|
1351 |
|
|
check_cast (last_arg_type, operand);
|
1352 |
|
|
}
|
1353 |
|
|
else
|
1354 |
|
|
/* The code reaches here for some unfortunate
|
1355 |
|
|
builtin functions that do not have a list of
|
1356 |
|
|
argument types. */
|
1357 |
|
|
break;
|
1358 |
|
|
}
|
1359 |
|
|
}
|
1360 |
|
|
else
|
1361 |
|
|
{
|
1362 |
|
|
/* FIXME - According to Geoff Keating, we should never
|
1363 |
|
|
have to do this; the front ends should always process
|
1364 |
|
|
the arg list from the TYPE_ARG_LIST. */
|
1365 |
|
|
for (arg_type = DECL_ARGUMENTS (callee_t), i = 0;
|
1366 |
|
|
arg_type && i < gimple_call_num_args (call);
|
1367 |
|
|
arg_type = TREE_CHAIN (arg_type), i++)
|
1368 |
|
|
{
|
1369 |
|
|
tree operand = gimple_call_arg (call, i);
|
1370 |
|
|
if (operand)
|
1371 |
|
|
{
|
1372 |
|
|
last_arg_type = TREE_TYPE (arg_type);
|
1373 |
|
|
check_cast (last_arg_type, operand);
|
1374 |
|
|
}
|
1375 |
|
|
else
|
1376 |
|
|
/* The code reaches here for some unfortunate
|
1377 |
|
|
builtin functions that do not have a list of
|
1378 |
|
|
argument types. */
|
1379 |
|
|
break;
|
1380 |
|
|
}
|
1381 |
|
|
}
|
1382 |
|
|
|
1383 |
|
|
/* In the case where we have a var_args function, we need to
|
1384 |
|
|
check the remaining parameters against the last argument. */
|
1385 |
|
|
arg_type = last_arg_type;
|
1386 |
|
|
for ( ; i < gimple_call_num_args (call); i++)
|
1387 |
|
|
{
|
1388 |
|
|
tree operand = gimple_call_arg (call, i);
|
1389 |
|
|
if (arg_type)
|
1390 |
|
|
check_cast (arg_type, operand);
|
1391 |
|
|
else
|
1392 |
|
|
{
|
1393 |
|
|
/* The code reaches here for some unfortunate
|
1394 |
|
|
builtin functions that do not have a list of
|
1395 |
|
|
argument types. Most of these functions have
|
1396 |
|
|
been marked as having their parameters not
|
1397 |
|
|
escape, but for the rest, the type is doomed. */
|
1398 |
|
|
tree type = get_canon_type (TREE_TYPE (operand), false, false);
|
1399 |
|
|
mark_interesting_type (type, FULL_ESCAPE);
|
1400 |
|
|
}
|
1401 |
|
|
}
|
1402 |
|
|
}
|
1403 |
|
|
|
1404 |
|
|
/* The callee is either unknown (indirect call) or there is just no
|
1405 |
|
|
scannable code for it (external call) . We look to see if there
|
1406 |
|
|
are any bits available for the callee (such as by declaration or
|
1407 |
|
|
because it is builtin) and process solely on the basis of those
|
1408 |
|
|
bits. */
|
1409 |
|
|
if (avail == AVAIL_NOT_AVAILABLE || avail == AVAIL_OVERWRITABLE)
|
1410 |
|
|
{
|
1411 |
|
|
/* If this is a direct call to an external function, mark all of
|
1412 |
|
|
the parameter and return types. */
|
1413 |
|
|
for (i = 0; i < gimple_call_num_args (call); i++)
|
1414 |
|
|
{
|
1415 |
|
|
tree operand = gimple_call_arg (call, i);
|
1416 |
|
|
tree type = get_canon_type (TREE_TYPE (operand), false, false);
|
1417 |
|
|
mark_interesting_type (type, EXPOSED_PARAMETER);
|
1418 |
|
|
}
|
1419 |
|
|
|
1420 |
|
|
if (callee_t)
|
1421 |
|
|
{
|
1422 |
|
|
tree type =
|
1423 |
|
|
get_canon_type (TREE_TYPE (TREE_TYPE (callee_t)), false, false);
|
1424 |
|
|
mark_interesting_type (type, EXPOSED_PARAMETER);
|
1425 |
|
|
}
|
1426 |
|
|
}
|
1427 |
|
|
}
|
1428 |
|
|
|
1429 |
|
|
/* CODE is the operation on OP0 and OP1. OP0 is the operand that we
|
1430 |
|
|
*know* is a pointer type. OP1 may be a pointer type. */
|
1431 |
|
|
static bool
|
1432 |
|
|
okay_pointer_operation (enum tree_code code, tree op0, tree op1)
|
1433 |
|
|
{
|
1434 |
|
|
tree op0type = TYPE_MAIN_VARIANT (TREE_TYPE (op0));
|
1435 |
|
|
|
1436 |
|
|
switch (code)
|
1437 |
|
|
{
|
1438 |
|
|
case MULT_EXPR:
|
1439 |
|
|
/* Multiplication does not change alignment. */
|
1440 |
|
|
return true;
|
1441 |
|
|
break;
|
1442 |
|
|
case MINUS_EXPR:
|
1443 |
|
|
case PLUS_EXPR:
|
1444 |
|
|
case POINTER_PLUS_EXPR:
|
1445 |
|
|
{
|
1446 |
|
|
tree base, offset;
|
1447 |
|
|
gimple offset_cast_stmt;
|
1448 |
|
|
|
1449 |
|
|
if (POINTER_TYPE_P (op0type)
|
1450 |
|
|
&& TREE_CODE (op0) == SSA_NAME
|
1451 |
|
|
&& TREE_CODE (op1) == SSA_NAME
|
1452 |
|
|
&& is_array_access_through_pointer_and_index (code, op0, op1,
|
1453 |
|
|
&base,
|
1454 |
|
|
&offset,
|
1455 |
|
|
&offset_cast_stmt))
|
1456 |
|
|
return true;
|
1457 |
|
|
else
|
1458 |
|
|
{
|
1459 |
|
|
tree size_of_op0_points_to = TYPE_SIZE_UNIT (TREE_TYPE (op0type));
|
1460 |
|
|
|
1461 |
|
|
if (CONSTANT_CLASS_P (op1)
|
1462 |
|
|
&& size_of_op0_points_to
|
1463 |
|
|
&& multiple_of_p (TREE_TYPE (size_of_op0_points_to),
|
1464 |
|
|
op1, size_of_op0_points_to))
|
1465 |
|
|
return true;
|
1466 |
|
|
|
1467 |
|
|
if (CONSTANT_CLASS_P (op0)
|
1468 |
|
|
&& size_of_op0_points_to
|
1469 |
|
|
&& multiple_of_p (TREE_TYPE (size_of_op0_points_to),
|
1470 |
|
|
op0, size_of_op0_points_to))
|
1471 |
|
|
return true;
|
1472 |
|
|
}
|
1473 |
|
|
}
|
1474 |
|
|
break;
|
1475 |
|
|
default:
|
1476 |
|
|
return false;
|
1477 |
|
|
}
|
1478 |
|
|
return false;
|
1479 |
|
|
}
|
1480 |
|
|
|
1481 |
|
|
|
1482 |
|
|
|
1483 |
|
|
/* Helper for scan_for_refs. Check the operands of an assignment to
|
1484 |
|
|
mark types that may escape. */
|
1485 |
|
|
|
1486 |
|
|
static void
|
1487 |
|
|
check_assign (gimple t)
|
1488 |
|
|
{
|
1489 |
|
|
/* First look on the lhs and see what variable is stored to */
|
1490 |
|
|
check_lhs_var (gimple_assign_lhs (t));
|
1491 |
|
|
|
1492 |
|
|
/* For the purposes of figuring out what the cast affects */
|
1493 |
|
|
|
1494 |
|
|
/* Next check the operands on the rhs to see if they are ok. */
|
1495 |
|
|
switch (TREE_CODE_CLASS (gimple_assign_rhs_code (t)))
|
1496 |
|
|
{
|
1497 |
|
|
case tcc_binary:
|
1498 |
|
|
{
|
1499 |
|
|
tree op0 = gimple_assign_rhs1 (t);
|
1500 |
|
|
tree type0 = get_canon_type (TREE_TYPE (op0), false, false);
|
1501 |
|
|
tree op1 = gimple_assign_rhs2 (t);
|
1502 |
|
|
tree type1 = get_canon_type (TREE_TYPE (op1), false, false);
|
1503 |
|
|
|
1504 |
|
|
/* If this is pointer arithmetic of any bad sort, then
|
1505 |
|
|
we need to mark the types as bad. For binary
|
1506 |
|
|
operations, no binary operator we currently support
|
1507 |
|
|
is always "safe" in regard to what it would do to
|
1508 |
|
|
pointers for purposes of determining which types
|
1509 |
|
|
escape, except operations of the size of the type.
|
1510 |
|
|
It is possible that min and max under the right set
|
1511 |
|
|
of circumstances and if the moon is in the correct
|
1512 |
|
|
place could be safe, but it is hard to see how this
|
1513 |
|
|
is worth the effort. */
|
1514 |
|
|
if (type0 && POINTER_TYPE_P (type0)
|
1515 |
|
|
&& !okay_pointer_operation (gimple_assign_rhs_code (t), op0, op1))
|
1516 |
|
|
mark_interesting_type (type0, FULL_ESCAPE);
|
1517 |
|
|
|
1518 |
|
|
if (type1 && POINTER_TYPE_P (type1)
|
1519 |
|
|
&& !okay_pointer_operation (gimple_assign_rhs_code (t), op1, op0))
|
1520 |
|
|
mark_interesting_type (type1, FULL_ESCAPE);
|
1521 |
|
|
|
1522 |
|
|
look_for_casts (op0);
|
1523 |
|
|
look_for_casts (op1);
|
1524 |
|
|
check_rhs_var (op0);
|
1525 |
|
|
check_rhs_var (op1);
|
1526 |
|
|
}
|
1527 |
|
|
break;
|
1528 |
|
|
|
1529 |
|
|
case tcc_unary:
|
1530 |
|
|
{
|
1531 |
|
|
tree op0 = gimple_assign_rhs1 (t);
|
1532 |
|
|
tree type0 = get_canon_type (TREE_TYPE (op0), false, false);
|
1533 |
|
|
|
1534 |
|
|
/* For unary operations, if the operation is NEGATE or ABS on
|
1535 |
|
|
a pointer, this is also considered pointer arithmetic and
|
1536 |
|
|
thus, bad for business. */
|
1537 |
|
|
if (type0
|
1538 |
|
|
&& POINTER_TYPE_P (type0)
|
1539 |
|
|
&& (TREE_CODE (op0) == NEGATE_EXPR
|
1540 |
|
|
|| TREE_CODE (op0) == ABS_EXPR))
|
1541 |
|
|
mark_interesting_type (type0, FULL_ESCAPE);
|
1542 |
|
|
|
1543 |
|
|
check_rhs_var (op0);
|
1544 |
|
|
look_for_casts (op0);
|
1545 |
|
|
}
|
1546 |
|
|
break;
|
1547 |
|
|
|
1548 |
|
|
case tcc_reference:
|
1549 |
|
|
look_for_casts (gimple_assign_rhs1 (t));
|
1550 |
|
|
check_rhs_var (gimple_assign_rhs1 (t));
|
1551 |
|
|
break;
|
1552 |
|
|
|
1553 |
|
|
case tcc_declaration:
|
1554 |
|
|
check_rhs_var (gimple_assign_rhs1 (t));
|
1555 |
|
|
break;
|
1556 |
|
|
|
1557 |
|
|
case tcc_expression:
|
1558 |
|
|
if (gimple_assign_rhs_code (t) == ADDR_EXPR)
|
1559 |
|
|
{
|
1560 |
|
|
tree rhs = gimple_assign_rhs1 (t);
|
1561 |
|
|
look_for_casts (TREE_OPERAND (rhs, 0));
|
1562 |
|
|
check_rhs_var (rhs);
|
1563 |
|
|
}
|
1564 |
|
|
break;
|
1565 |
|
|
|
1566 |
|
|
default:
|
1567 |
|
|
break;
|
1568 |
|
|
}
|
1569 |
|
|
}
|
1570 |
|
|
|
1571 |
|
|
|
1572 |
|
|
/* Scan statement T for references to types and mark anything
|
1573 |
|
|
interesting. */
|
1574 |
|
|
|
1575 |
|
|
static void
|
1576 |
|
|
scan_for_refs (gimple t)
|
1577 |
|
|
{
|
1578 |
|
|
switch (gimple_code (t))
|
1579 |
|
|
{
|
1580 |
|
|
case GIMPLE_ASSIGN:
|
1581 |
|
|
check_assign (t);
|
1582 |
|
|
break;
|
1583 |
|
|
|
1584 |
|
|
case GIMPLE_CALL:
|
1585 |
|
|
/* If this is a call to malloc, squirrel away the result so we
|
1586 |
|
|
do mark the resulting cast as being bad. */
|
1587 |
|
|
check_call (t);
|
1588 |
|
|
break;
|
1589 |
|
|
|
1590 |
|
|
case GIMPLE_ASM:
|
1591 |
|
|
check_asm (t);
|
1592 |
|
|
break;
|
1593 |
|
|
|
1594 |
|
|
default:
|
1595 |
|
|
break;
|
1596 |
|
|
}
|
1597 |
|
|
|
1598 |
|
|
return;
|
1599 |
|
|
}
|
1600 |
|
|
|
1601 |
|
|
|
1602 |
|
|
/* The init routine for analyzing global static variable usage. See
|
1603 |
|
|
comments at top for description. */
|
1604 |
|
|
static void
|
1605 |
|
|
ipa_init (void)
|
1606 |
|
|
{
|
1607 |
|
|
bitmap_obstack_initialize (&ipa_obstack);
|
1608 |
|
|
global_types_exposed_parameter = BITMAP_ALLOC (&ipa_obstack);
|
1609 |
|
|
global_types_full_escape = BITMAP_ALLOC (&ipa_obstack);
|
1610 |
|
|
global_types_seen = BITMAP_ALLOC (&ipa_obstack);
|
1611 |
|
|
|
1612 |
|
|
uid_to_canon_type = splay_tree_new (splay_tree_compare_ints, 0, 0);
|
1613 |
|
|
all_canon_types = splay_tree_new (compare_type_brand, 0, 0);
|
1614 |
|
|
type_to_canon_type = splay_tree_new (splay_tree_compare_pointers, 0, 0);
|
1615 |
|
|
uid_to_subtype_map = splay_tree_new (splay_tree_compare_ints, 0, 0);
|
1616 |
|
|
uid_to_addressof_down_map = splay_tree_new (splay_tree_compare_ints, 0, 0);
|
1617 |
|
|
uid_to_addressof_up_map = splay_tree_new (splay_tree_compare_ints, 0, 0);
|
1618 |
|
|
|
1619 |
|
|
/* There are some shared nodes, in particular the initializers on
|
1620 |
|
|
static declarations. We do not need to scan them more than once
|
1621 |
|
|
since all we would be interested in are the addressof
|
1622 |
|
|
operations. */
|
1623 |
|
|
visited_nodes = pointer_set_create ();
|
1624 |
|
|
initialized = true;
|
1625 |
|
|
}
|
1626 |
|
|
|
1627 |
|
|
/* Check out the rhs of a static or global initialization VNODE to see
|
1628 |
|
|
if any of them contain addressof operations. Note that some of
|
1629 |
|
|
these variables may not even be referenced in the code in this
|
1630 |
|
|
compilation unit but their right hand sides may contain references
|
1631 |
|
|
to variables defined within this unit. */
|
1632 |
|
|
|
1633 |
|
|
static void
|
1634 |
|
|
analyze_variable (struct varpool_node *vnode)
|
1635 |
|
|
{
|
1636 |
|
|
tree global = vnode->decl;
|
1637 |
|
|
tree type = get_canon_type (TREE_TYPE (global), false, false);
|
1638 |
|
|
|
1639 |
|
|
/* If this variable has exposure beyond the compilation unit, add
|
1640 |
|
|
its type to the global types. */
|
1641 |
|
|
|
1642 |
|
|
if (vnode->externally_visible)
|
1643 |
|
|
mark_interesting_type (type, FULL_ESCAPE);
|
1644 |
|
|
|
1645 |
|
|
gcc_assert (TREE_CODE (global) == VAR_DECL);
|
1646 |
|
|
|
1647 |
|
|
if (DECL_INITIAL (global))
|
1648 |
|
|
check_tree (DECL_INITIAL (global));
|
1649 |
|
|
}
|
1650 |
|
|
|
1651 |
|
|
/* This is the main routine for finding the reference patterns for
|
1652 |
|
|
global variables within a function FN. */
|
1653 |
|
|
|
1654 |
|
|
static void
|
1655 |
|
|
analyze_function (struct cgraph_node *fn)
|
1656 |
|
|
{
|
1657 |
|
|
tree decl = fn->decl;
|
1658 |
|
|
check_function_parameter_and_return_types (decl,
|
1659 |
|
|
fn->local.externally_visible);
|
1660 |
|
|
if (dump_file)
|
1661 |
|
|
fprintf (dump_file, "\n local analysis of %s", cgraph_node_name (fn));
|
1662 |
|
|
|
1663 |
|
|
{
|
1664 |
|
|
struct function *this_cfun = DECL_STRUCT_FUNCTION (decl);
|
1665 |
|
|
basic_block this_block;
|
1666 |
|
|
|
1667 |
|
|
FOR_EACH_BB_FN (this_block, this_cfun)
|
1668 |
|
|
{
|
1669 |
|
|
gimple_stmt_iterator gsi;
|
1670 |
|
|
for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi))
|
1671 |
|
|
scan_for_refs (gsi_stmt (gsi));
|
1672 |
|
|
}
|
1673 |
|
|
}
|
1674 |
|
|
|
1675 |
|
|
/* There may be const decls with interesting right hand sides. */
|
1676 |
|
|
if (DECL_STRUCT_FUNCTION (decl))
|
1677 |
|
|
{
|
1678 |
|
|
tree step;
|
1679 |
|
|
for (step = DECL_STRUCT_FUNCTION (decl)->local_decls;
|
1680 |
|
|
step;
|
1681 |
|
|
step = TREE_CHAIN (step))
|
1682 |
|
|
{
|
1683 |
|
|
tree var = TREE_VALUE (step);
|
1684 |
|
|
if (TREE_CODE (var) == VAR_DECL
|
1685 |
|
|
&& DECL_INITIAL (var)
|
1686 |
|
|
&& !TREE_STATIC (var))
|
1687 |
|
|
check_tree (DECL_INITIAL (var));
|
1688 |
|
|
get_canon_type (TREE_TYPE (var), false, false);
|
1689 |
|
|
}
|
1690 |
|
|
}
|
1691 |
|
|
}
|
1692 |
|
|
|
1693 |
|
|
|
1694 |
|
|
|
1695 |
|
|
/* Convert a type_UID into a type. */
|
1696 |
|
|
static tree
|
1697 |
|
|
type_for_uid (int uid)
|
1698 |
|
|
{
|
1699 |
|
|
splay_tree_node result =
|
1700 |
|
|
splay_tree_lookup (uid_to_canon_type, (splay_tree_key) uid);
|
1701 |
|
|
|
1702 |
|
|
if (result)
|
1703 |
|
|
return (tree) result->value;
|
1704 |
|
|
else return NULL;
|
1705 |
|
|
}
|
1706 |
|
|
|
1707 |
|
|
/* Return a bitmap with the subtypes of the type for UID. If it
|
1708 |
|
|
does not exist, return either NULL or a new bitmap depending on the
|
1709 |
|
|
value of CREATE. */
|
1710 |
|
|
|
1711 |
|
|
static bitmap
|
1712 |
|
|
subtype_map_for_uid (int uid, bool create)
|
1713 |
|
|
{
|
1714 |
|
|
splay_tree_node result = splay_tree_lookup (uid_to_subtype_map,
|
1715 |
|
|
(splay_tree_key) uid);
|
1716 |
|
|
|
1717 |
|
|
if (result)
|
1718 |
|
|
return (bitmap) result->value;
|
1719 |
|
|
else if (create)
|
1720 |
|
|
{
|
1721 |
|
|
bitmap subtype_map = BITMAP_ALLOC (&ipa_obstack);
|
1722 |
|
|
splay_tree_insert (uid_to_subtype_map,
|
1723 |
|
|
uid,
|
1724 |
|
|
(splay_tree_value)subtype_map);
|
1725 |
|
|
return subtype_map;
|
1726 |
|
|
}
|
1727 |
|
|
else return NULL;
|
1728 |
|
|
}
|
1729 |
|
|
|
1730 |
|
|
/* Mark all of the supertypes and field types of TYPE as being seen.
|
1731 |
|
|
Also accumulate the subtypes for each type so that
|
1732 |
|
|
close_types_full_escape can mark a subtype as escaping if the
|
1733 |
|
|
supertype escapes. */
|
1734 |
|
|
|
1735 |
|
|
static void
|
1736 |
|
|
close_type_seen (tree type)
|
1737 |
|
|
{
|
1738 |
|
|
tree field;
|
1739 |
|
|
int i, uid;
|
1740 |
|
|
tree binfo, base_binfo;
|
1741 |
|
|
|
1742 |
|
|
/* See thru all pointer tos and array ofs. */
|
1743 |
|
|
type = get_canon_type (type, true, true);
|
1744 |
|
|
if (!type)
|
1745 |
|
|
return;
|
1746 |
|
|
|
1747 |
|
|
uid = TYPE_UID (type);
|
1748 |
|
|
|
1749 |
|
|
if (bitmap_bit_p (been_there_done_that, uid))
|
1750 |
|
|
return;
|
1751 |
|
|
bitmap_set_bit (been_there_done_that, uid);
|
1752 |
|
|
|
1753 |
|
|
/* If we are doing a language with a type hierarchy, mark all of
|
1754 |
|
|
the superclasses. */
|
1755 |
|
|
if (TYPE_BINFO (type))
|
1756 |
|
|
for (binfo = TYPE_BINFO (type), i = 0;
|
1757 |
|
|
BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
|
1758 |
|
|
{
|
1759 |
|
|
tree binfo_type = BINFO_TYPE (base_binfo);
|
1760 |
|
|
bitmap subtype_map = subtype_map_for_uid
|
1761 |
|
|
(TYPE_UID (TYPE_MAIN_VARIANT (binfo_type)), true);
|
1762 |
|
|
bitmap_set_bit (subtype_map, uid);
|
1763 |
|
|
close_type_seen (get_canon_type (binfo_type, true, true));
|
1764 |
|
|
}
|
1765 |
|
|
|
1766 |
|
|
/* If the field is a struct or union type, mark all of the
|
1767 |
|
|
subfields. */
|
1768 |
|
|
for (field = TYPE_FIELDS (type);
|
1769 |
|
|
field;
|
1770 |
|
|
field = TREE_CHAIN (field))
|
1771 |
|
|
{
|
1772 |
|
|
tree field_type;
|
1773 |
|
|
if (TREE_CODE (field) != FIELD_DECL)
|
1774 |
|
|
continue;
|
1775 |
|
|
|
1776 |
|
|
field_type = TREE_TYPE (field);
|
1777 |
|
|
if (ipa_type_escape_star_count_of_interesting_or_array_type (field_type) >= 0)
|
1778 |
|
|
close_type_seen (get_canon_type (field_type, true, true));
|
1779 |
|
|
}
|
1780 |
|
|
}
|
1781 |
|
|
|
1782 |
|
|
/* Take a TYPE that has been passed by value to an external function
|
1783 |
|
|
and mark all of the fields that have pointer types as escaping. For
|
1784 |
|
|
any of the non pointer types that are structures or unions,
|
1785 |
|
|
recurse. TYPE is never a pointer type. */
|
1786 |
|
|
|
1787 |
|
|
static void
|
1788 |
|
|
close_type_exposed_parameter (tree type)
|
1789 |
|
|
{
|
1790 |
|
|
tree field;
|
1791 |
|
|
int uid;
|
1792 |
|
|
|
1793 |
|
|
type = get_canon_type (type, false, false);
|
1794 |
|
|
if (!type)
|
1795 |
|
|
return;
|
1796 |
|
|
uid = TYPE_UID (type);
|
1797 |
|
|
gcc_assert (!POINTER_TYPE_P (type));
|
1798 |
|
|
|
1799 |
|
|
if (bitmap_bit_p (been_there_done_that, uid))
|
1800 |
|
|
return;
|
1801 |
|
|
bitmap_set_bit (been_there_done_that, uid);
|
1802 |
|
|
|
1803 |
|
|
/* If the field is a struct or union type, mark all of the
|
1804 |
|
|
subfields. */
|
1805 |
|
|
for (field = TYPE_FIELDS (type);
|
1806 |
|
|
field;
|
1807 |
|
|
field = TREE_CHAIN (field))
|
1808 |
|
|
{
|
1809 |
|
|
tree field_type;
|
1810 |
|
|
|
1811 |
|
|
if (TREE_CODE (field) != FIELD_DECL)
|
1812 |
|
|
continue;
|
1813 |
|
|
|
1814 |
|
|
field_type = get_canon_type (TREE_TYPE (field), false, false);
|
1815 |
|
|
mark_interesting_type (field_type, EXPOSED_PARAMETER);
|
1816 |
|
|
|
1817 |
|
|
/* Only recurse for non pointer types of structures and unions. */
|
1818 |
|
|
if (ipa_type_escape_star_count_of_interesting_type (field_type) == 0)
|
1819 |
|
|
close_type_exposed_parameter (field_type);
|
1820 |
|
|
}
|
1821 |
|
|
}
|
1822 |
|
|
|
1823 |
|
|
/* The next function handles the case where a type fully escapes.
|
1824 |
|
|
This means that not only does the type itself escape,
|
1825 |
|
|
|
1826 |
|
|
a) the type of every field recursively escapes
|
1827 |
|
|
b) the type of every subtype escapes as well as the super as well
|
1828 |
|
|
as all of the pointer to types for each field.
|
1829 |
|
|
|
1830 |
|
|
Note that pointer to types are not marked as escaping. If the
|
1831 |
|
|
pointed to type escapes, the pointer to type also escapes.
|
1832 |
|
|
|
1833 |
|
|
Take a TYPE that has had the address taken for an instance of it
|
1834 |
|
|
and mark all of the types for its fields as having their addresses
|
1835 |
|
|
taken. */
|
1836 |
|
|
|
1837 |
|
|
static void
|
1838 |
|
|
close_type_full_escape (tree type)
|
1839 |
|
|
{
|
1840 |
|
|
tree field;
|
1841 |
|
|
unsigned int i;
|
1842 |
|
|
int uid;
|
1843 |
|
|
tree binfo, base_binfo;
|
1844 |
|
|
bitmap_iterator bi;
|
1845 |
|
|
bitmap subtype_map;
|
1846 |
|
|
splay_tree_node address_result;
|
1847 |
|
|
|
1848 |
|
|
/* Strip off any pointer or array types. */
|
1849 |
|
|
type = get_canon_type (type, true, true);
|
1850 |
|
|
if (!type)
|
1851 |
|
|
return;
|
1852 |
|
|
uid = TYPE_UID (type);
|
1853 |
|
|
|
1854 |
|
|
if (bitmap_bit_p (been_there_done_that, uid))
|
1855 |
|
|
return;
|
1856 |
|
|
bitmap_set_bit (been_there_done_that, uid);
|
1857 |
|
|
|
1858 |
|
|
subtype_map = subtype_map_for_uid (uid, false);
|
1859 |
|
|
|
1860 |
|
|
/* If we are doing a language with a type hierarchy, mark all of
|
1861 |
|
|
the superclasses. */
|
1862 |
|
|
if (TYPE_BINFO (type))
|
1863 |
|
|
for (binfo = TYPE_BINFO (type), i = 0;
|
1864 |
|
|
BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
|
1865 |
|
|
{
|
1866 |
|
|
tree binfotype = BINFO_TYPE (base_binfo);
|
1867 |
|
|
binfotype = mark_type (binfotype, FULL_ESCAPE);
|
1868 |
|
|
close_type_full_escape (binfotype);
|
1869 |
|
|
}
|
1870 |
|
|
|
1871 |
|
|
/* Mark as escaped any types that have been down casted to
|
1872 |
|
|
this type. */
|
1873 |
|
|
if (subtype_map)
|
1874 |
|
|
EXECUTE_IF_SET_IN_BITMAP (subtype_map, 0, i, bi)
|
1875 |
|
|
{
|
1876 |
|
|
tree subtype = type_for_uid (i);
|
1877 |
|
|
subtype = mark_type (subtype, FULL_ESCAPE);
|
1878 |
|
|
close_type_full_escape (subtype);
|
1879 |
|
|
}
|
1880 |
|
|
|
1881 |
|
|
/* If the field is a struct or union type, mark all of the
|
1882 |
|
|
subfields. */
|
1883 |
|
|
for (field = TYPE_FIELDS (type);
|
1884 |
|
|
field;
|
1885 |
|
|
field = TREE_CHAIN (field))
|
1886 |
|
|
{
|
1887 |
|
|
tree field_type;
|
1888 |
|
|
if (TREE_CODE (field) != FIELD_DECL)
|
1889 |
|
|
continue;
|
1890 |
|
|
|
1891 |
|
|
field_type = TREE_TYPE (field);
|
1892 |
|
|
if (ipa_type_escape_star_count_of_interesting_or_array_type (field_type) >= 0)
|
1893 |
|
|
{
|
1894 |
|
|
field_type = mark_type (field_type, FULL_ESCAPE);
|
1895 |
|
|
close_type_full_escape (field_type);
|
1896 |
|
|
}
|
1897 |
|
|
}
|
1898 |
|
|
|
1899 |
|
|
/* For all of the types A that contain this type B and were part of
|
1900 |
|
|
an expression like "&...A.B...", mark the A's as escaping. */
|
1901 |
|
|
address_result = splay_tree_lookup (uid_to_addressof_up_map,
|
1902 |
|
|
(splay_tree_key) uid);
|
1903 |
|
|
if (address_result)
|
1904 |
|
|
{
|
1905 |
|
|
bitmap containing_classes = (bitmap) address_result->value;
|
1906 |
|
|
EXECUTE_IF_SET_IN_BITMAP (containing_classes, 0, i, bi)
|
1907 |
|
|
{
|
1908 |
|
|
close_type_full_escape (type_for_uid (i));
|
1909 |
|
|
}
|
1910 |
|
|
}
|
1911 |
|
|
}
|
1912 |
|
|
|
1913 |
|
|
/* Transitively close the addressof bitmap for the type with UID.
|
1914 |
|
|
This means that if we had a.b and b.c, a would have both b and c in
|
1915 |
|
|
its maps. */
|
1916 |
|
|
|
1917 |
|
|
static bitmap
|
1918 |
|
|
close_addressof_down (int uid)
|
1919 |
|
|
{
|
1920 |
|
|
bitmap_iterator bi;
|
1921 |
|
|
splay_tree_node result =
|
1922 |
|
|
splay_tree_lookup (uid_to_addressof_down_map, (splay_tree_key) uid);
|
1923 |
|
|
bitmap map = NULL;
|
1924 |
|
|
bitmap new_map;
|
1925 |
|
|
unsigned int i;
|
1926 |
|
|
|
1927 |
|
|
if (result)
|
1928 |
|
|
map = (bitmap) result->value;
|
1929 |
|
|
else
|
1930 |
|
|
return NULL;
|
1931 |
|
|
|
1932 |
|
|
if (bitmap_bit_p (been_there_done_that, uid))
|
1933 |
|
|
return map;
|
1934 |
|
|
bitmap_set_bit (been_there_done_that, uid);
|
1935 |
|
|
|
1936 |
|
|
/* If the type escapes, get rid of the addressof map, it will not be
|
1937 |
|
|
needed. */
|
1938 |
|
|
if (bitmap_bit_p (global_types_full_escape, uid))
|
1939 |
|
|
{
|
1940 |
|
|
BITMAP_FREE (map);
|
1941 |
|
|
splay_tree_remove (uid_to_addressof_down_map, (splay_tree_key) uid);
|
1942 |
|
|
return NULL;
|
1943 |
|
|
}
|
1944 |
|
|
|
1945 |
|
|
/* The new_map will have all of the bits for the enclosed fields and
|
1946 |
|
|
will have the unique id version of the old map. */
|
1947 |
|
|
new_map = BITMAP_ALLOC (&ipa_obstack);
|
1948 |
|
|
|
1949 |
|
|
EXECUTE_IF_SET_IN_BITMAP (map, 0, i, bi)
|
1950 |
|
|
{
|
1951 |
|
|
bitmap submap = close_addressof_down (i);
|
1952 |
|
|
bitmap_set_bit (new_map, i);
|
1953 |
|
|
if (submap)
|
1954 |
|
|
bitmap_ior_into (new_map, submap);
|
1955 |
|
|
}
|
1956 |
|
|
result->value = (splay_tree_value) new_map;
|
1957 |
|
|
|
1958 |
|
|
BITMAP_FREE (map);
|
1959 |
|
|
return new_map;
|
1960 |
|
|
}
|
1961 |
|
|
|
1962 |
|
|
|
1963 |
|
|
/* The main entry point for type escape analysis. */
|
1964 |
|
|
|
1965 |
|
|
static unsigned int
|
1966 |
|
|
type_escape_execute (void)
|
1967 |
|
|
{
|
1968 |
|
|
struct cgraph_node *node;
|
1969 |
|
|
struct varpool_node *vnode;
|
1970 |
|
|
unsigned int i;
|
1971 |
|
|
bitmap_iterator bi;
|
1972 |
|
|
splay_tree_node result;
|
1973 |
|
|
|
1974 |
|
|
ipa_init ();
|
1975 |
|
|
|
1976 |
|
|
/* Process all of the variables first. */
|
1977 |
|
|
FOR_EACH_STATIC_VARIABLE (vnode)
|
1978 |
|
|
analyze_variable (vnode);
|
1979 |
|
|
|
1980 |
|
|
/* Process all of the functions next.
|
1981 |
|
|
|
1982 |
|
|
We do not want to process any of the clones so we check that this
|
1983 |
|
|
is a master clone. However, we do need to process any
|
1984 |
|
|
AVAIL_OVERWRITABLE functions (these are never clones) because
|
1985 |
|
|
they may cause a type variable to escape.
|
1986 |
|
|
*/
|
1987 |
|
|
for (node = cgraph_nodes; node; node = node->next)
|
1988 |
|
|
if (node->analyzed && !node->clone_of)
|
1989 |
|
|
analyze_function (node);
|
1990 |
|
|
|
1991 |
|
|
|
1992 |
|
|
pointer_set_destroy (visited_nodes);
|
1993 |
|
|
visited_nodes = NULL;
|
1994 |
|
|
|
1995 |
|
|
/* Do all of the closures to discover which types escape the
|
1996 |
|
|
compilation unit. */
|
1997 |
|
|
|
1998 |
|
|
been_there_done_that = BITMAP_ALLOC (&ipa_obstack);
|
1999 |
|
|
bitmap_tmp = BITMAP_ALLOC (&ipa_obstack);
|
2000 |
|
|
|
2001 |
|
|
/* Examine the types that we have directly seen in scanning the code
|
2002 |
|
|
and add to that any contained types or superclasses. */
|
2003 |
|
|
|
2004 |
|
|
bitmap_copy (bitmap_tmp, global_types_seen);
|
2005 |
|
|
EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp, 0, i, bi)
|
2006 |
|
|
{
|
2007 |
|
|
tree type = type_for_uid (i);
|
2008 |
|
|
/* Only look at records and unions and pointer tos. */
|
2009 |
|
|
if (ipa_type_escape_star_count_of_interesting_or_array_type (type) >= 0)
|
2010 |
|
|
close_type_seen (type);
|
2011 |
|
|
}
|
2012 |
|
|
bitmap_clear (been_there_done_that);
|
2013 |
|
|
|
2014 |
|
|
/* Examine all of the types passed by value and mark any enclosed
|
2015 |
|
|
pointer types as escaping. */
|
2016 |
|
|
bitmap_copy (bitmap_tmp, global_types_exposed_parameter);
|
2017 |
|
|
EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp, 0, i, bi)
|
2018 |
|
|
{
|
2019 |
|
|
close_type_exposed_parameter (type_for_uid (i));
|
2020 |
|
|
}
|
2021 |
|
|
bitmap_clear (been_there_done_that);
|
2022 |
|
|
|
2023 |
|
|
/* Close the types for escape. If something escapes, then any
|
2024 |
|
|
enclosed types escape as well as any subtypes. */
|
2025 |
|
|
bitmap_copy (bitmap_tmp, global_types_full_escape);
|
2026 |
|
|
EXECUTE_IF_SET_IN_BITMAP (bitmap_tmp, 0, i, bi)
|
2027 |
|
|
{
|
2028 |
|
|
close_type_full_escape (type_for_uid (i));
|
2029 |
|
|
}
|
2030 |
|
|
bitmap_clear (been_there_done_that);
|
2031 |
|
|
|
2032 |
|
|
/* Before this pass, the uid_to_addressof_down_map for type X
|
2033 |
|
|
contained an entry for Y if there had been an operation of the
|
2034 |
|
|
form &X.Y. This step adds all of the fields contained within Y
|
2035 |
|
|
(recursively) to X's map. */
|
2036 |
|
|
|
2037 |
|
|
result = splay_tree_min (uid_to_addressof_down_map);
|
2038 |
|
|
while (result)
|
2039 |
|
|
{
|
2040 |
|
|
int uid = result->key;
|
2041 |
|
|
/* Close the addressof map, i.e. copy all of the transitive
|
2042 |
|
|
substructures up to this level. */
|
2043 |
|
|
close_addressof_down (uid);
|
2044 |
|
|
result = splay_tree_successor (uid_to_addressof_down_map, uid);
|
2045 |
|
|
}
|
2046 |
|
|
|
2047 |
|
|
/* Do not need the array types and pointer types in the persistent
|
2048 |
|
|
data structures. */
|
2049 |
|
|
result = splay_tree_min (all_canon_types);
|
2050 |
|
|
while (result)
|
2051 |
|
|
{
|
2052 |
|
|
tree type = (tree) result->value;
|
2053 |
|
|
tree key = (tree) result->key;
|
2054 |
|
|
if (POINTER_TYPE_P (type)
|
2055 |
|
|
|| TREE_CODE (type) == ARRAY_TYPE)
|
2056 |
|
|
{
|
2057 |
|
|
splay_tree_remove (all_canon_types, (splay_tree_key) result->key);
|
2058 |
|
|
splay_tree_remove (type_to_canon_type, (splay_tree_key) type);
|
2059 |
|
|
splay_tree_remove (uid_to_canon_type, (splay_tree_key) TYPE_UID (type));
|
2060 |
|
|
bitmap_clear_bit (global_types_seen, TYPE_UID (type));
|
2061 |
|
|
}
|
2062 |
|
|
result = splay_tree_successor (all_canon_types, (splay_tree_key) key);
|
2063 |
|
|
}
|
2064 |
|
|
|
2065 |
|
|
if (dump_file)
|
2066 |
|
|
{
|
2067 |
|
|
EXECUTE_IF_SET_IN_BITMAP (global_types_seen, 0, i, bi)
|
2068 |
|
|
{
|
2069 |
|
|
/* The pointer types are in the global_types_full_escape
|
2070 |
|
|
bitmap but not in the backwards map. They also contain
|
2071 |
|
|
no useful information since they are not marked. */
|
2072 |
|
|
tree type = type_for_uid (i);
|
2073 |
|
|
fprintf(dump_file, "type %d ", i);
|
2074 |
|
|
print_generic_expr (dump_file, type, 0);
|
2075 |
|
|
if (bitmap_bit_p (global_types_full_escape, i))
|
2076 |
|
|
fprintf(dump_file, " escaped\n");
|
2077 |
|
|
else
|
2078 |
|
|
fprintf(dump_file, " contained\n");
|
2079 |
|
|
}
|
2080 |
|
|
}
|
2081 |
|
|
|
2082 |
|
|
/* Get rid of uid_to_addressof_up_map and its bitmaps. */
|
2083 |
|
|
result = splay_tree_min (uid_to_addressof_up_map);
|
2084 |
|
|
while (result)
|
2085 |
|
|
{
|
2086 |
|
|
int uid = (int)result->key;
|
2087 |
|
|
bitmap bm = (bitmap)result->value;
|
2088 |
|
|
|
2089 |
|
|
BITMAP_FREE (bm);
|
2090 |
|
|
splay_tree_remove (uid_to_addressof_up_map, (splay_tree_key) uid);
|
2091 |
|
|
result = splay_tree_successor (uid_to_addressof_up_map, uid);
|
2092 |
|
|
}
|
2093 |
|
|
|
2094 |
|
|
/* Get rid of the subtype map. */
|
2095 |
|
|
result = splay_tree_min (uid_to_subtype_map);
|
2096 |
|
|
while (result)
|
2097 |
|
|
{
|
2098 |
|
|
bitmap b = (bitmap)result->value;
|
2099 |
|
|
BITMAP_FREE(b);
|
2100 |
|
|
splay_tree_remove (uid_to_subtype_map, result->key);
|
2101 |
|
|
result = splay_tree_min (uid_to_subtype_map);
|
2102 |
|
|
}
|
2103 |
|
|
splay_tree_delete (uid_to_subtype_map);
|
2104 |
|
|
uid_to_subtype_map = NULL;
|
2105 |
|
|
|
2106 |
|
|
BITMAP_FREE (global_types_exposed_parameter);
|
2107 |
|
|
BITMAP_FREE (been_there_done_that);
|
2108 |
|
|
BITMAP_FREE (bitmap_tmp);
|
2109 |
|
|
return 0;
|
2110 |
|
|
}
|
2111 |
|
|
|
2112 |
|
|
static bool
|
2113 |
|
|
gate_type_escape_vars (void)
|
2114 |
|
|
{
|
2115 |
|
|
return (flag_ipa_type_escape
|
2116 |
|
|
/* Don't bother doing anything if the program has errors. */
|
2117 |
|
|
&& !(errorcount || sorrycount));
|
2118 |
|
|
}
|
2119 |
|
|
|
2120 |
|
|
struct simple_ipa_opt_pass pass_ipa_type_escape =
|
2121 |
|
|
{
|
2122 |
|
|
{
|
2123 |
|
|
SIMPLE_IPA_PASS,
|
2124 |
|
|
"type-escape-var", /* name */
|
2125 |
|
|
gate_type_escape_vars, /* gate */
|
2126 |
|
|
type_escape_execute, /* execute */
|
2127 |
|
|
NULL, /* sub */
|
2128 |
|
|
NULL, /* next */
|
2129 |
|
|
0, /* static_pass_number */
|
2130 |
|
|
TV_IPA_TYPE_ESCAPE, /* tv_id */
|
2131 |
|
|
0, /* properties_required */
|
2132 |
|
|
0, /* properties_provided */
|
2133 |
|
|
0, /* properties_destroyed */
|
2134 |
|
|
0, /* todo_flags_start */
|
2135 |
|
|
|
2136 |
|
|
}
|
2137 |
|
|
};
|