/* Perform optimizations on tree structure. Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. Written by Mark Michell (mark@codesourcery.com). This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see . */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "tree.h" #include "cp-tree.h" #include "input.h" #include "params.h" #include "hashtab.h" #include "target.h" #include "debug.h" #include "tree-inline.h" #include "flags.h" #include "langhooks.h" #include "diagnostic-core.h" #include "tree-dump.h" #include "gimple.h" #include "tree-iterator.h" #include "cgraph.h" /* Prototypes. */ static void update_cloned_parm (tree, tree, bool); /* CLONED_PARM is a copy of CLONE, generated for a cloned constructor or destructor. Update it to ensure that the source-position for the cloned parameter matches that for the original, and that the debugging generation code will be able to find the original PARM. */ static void update_cloned_parm (tree parm, tree cloned_parm, bool first) { DECL_ABSTRACT_ORIGIN (cloned_parm) = parm; /* We may have taken its address. */ TREE_ADDRESSABLE (cloned_parm) = TREE_ADDRESSABLE (parm); /* The definition might have different constness. */ TREE_READONLY (cloned_parm) = TREE_READONLY (parm); TREE_USED (cloned_parm) = !first || TREE_USED (parm); /* The name may have changed from the declaration. */ DECL_NAME (cloned_parm) = DECL_NAME (parm); DECL_SOURCE_LOCATION (cloned_parm) = DECL_SOURCE_LOCATION (parm); TREE_TYPE (cloned_parm) = TREE_TYPE (parm); DECL_GIMPLE_REG_P (cloned_parm) = DECL_GIMPLE_REG_P (parm); } /* FN is a function in High GIMPLE form that has a complete body and no CFG. CLONE is a function whose body is to be set to a copy of FN, mapping argument declarations according to the ARG_MAP splay_tree. */ static void clone_body (tree clone, tree fn, void *arg_map) { copy_body_data id; tree stmts; /* Clone the body, as if we were making an inline call. But, remap the parameters in the callee to the parameters of caller. */ memset (&id, 0, sizeof (id)); id.src_fn = fn; id.dst_fn = clone; id.src_cfun = DECL_STRUCT_FUNCTION (fn); id.decl_map = (struct pointer_map_t *) arg_map; id.copy_decl = copy_decl_no_change; id.transform_call_graph_edges = CB_CGE_DUPLICATE; id.transform_new_cfg = true; id.transform_return_to_modify = false; id.transform_lang_insert_block = NULL; /* We're not inside any EH region. */ id.eh_lp_nr = 0; stmts = DECL_SAVED_TREE (fn); walk_tree (&stmts, copy_tree_body_r, &id, NULL); /* Also remap the initializer of any static variables so that they (in particular, any label addresses) correspond to the base variant rather than the abstract one. */ if (DECL_NAME (clone) == base_dtor_identifier || DECL_NAME (clone) == base_ctor_identifier) { unsigned ix; tree decl; FOR_EACH_LOCAL_DECL (DECL_STRUCT_FUNCTION (fn), ix, decl) walk_tree (&DECL_INITIAL (decl), copy_tree_body_r, &id, NULL); } append_to_statement_list_force (stmts, &DECL_SAVED_TREE (clone)); } /* DELETE_DTOR is a delete destructor whose body will be built. COMPLETE_DTOR is the corresponding complete destructor. */ static void build_delete_destructor_body (tree delete_dtor, tree complete_dtor) { tree call_dtor, call_delete; tree parm = DECL_ARGUMENTS (delete_dtor); tree virtual_size = cxx_sizeof (current_class_type); /* Call the corresponding complete destructor. */ gcc_assert (complete_dtor); call_dtor = build_cxx_call (complete_dtor, 1, &parm); add_stmt (call_dtor); add_stmt (build_stmt (0, LABEL_EXPR, cdtor_label)); /* Call the delete function. */ call_delete = build_op_delete_call (DELETE_EXPR, current_class_ptr, virtual_size, /*global_p=*/false, /*placement=*/NULL_TREE, /*alloc_fn=*/NULL_TREE); add_stmt (call_delete); /* Return the address of the object. */ if (targetm.cxx.cdtor_returns_this ()) { tree val = DECL_ARGUMENTS (delete_dtor); val = build2 (MODIFY_EXPR, TREE_TYPE (val), DECL_RESULT (delete_dtor), val); add_stmt (build_stmt (0, RETURN_EXPR, val)); } } /* Return name of comdat group for complete and base ctor (or dtor) that have the same body. If dtor is virtual, deleting dtor goes into this comdat group as well. */ static tree cdtor_comdat_group (tree complete, tree base) { tree complete_name = DECL_COMDAT_GROUP (complete); tree base_name = DECL_COMDAT_GROUP (base); char *grp_name; const char *p, *q; bool diff_seen = false; size_t idx; if (complete_name == NULL) complete_name = cxx_comdat_group (complete); if (base_name == NULL) base_name = cxx_comdat_group (base); gcc_assert (IDENTIFIER_LENGTH (complete_name) == IDENTIFIER_LENGTH (base_name)); grp_name = XALLOCAVEC (char, IDENTIFIER_LENGTH (complete_name) + 1); p = IDENTIFIER_POINTER (complete_name); q = IDENTIFIER_POINTER (base_name); for (idx = 0; idx < IDENTIFIER_LENGTH (complete_name); idx++) if (p[idx] == q[idx]) grp_name[idx] = p[idx]; else { gcc_assert (!diff_seen && idx > 0 && (p[idx - 1] == 'C' || p[idx - 1] == 'D') && p[idx] == '1' && q[idx] == '2'); grp_name[idx] = '5'; diff_seen = true; } grp_name[idx] = '\0'; gcc_assert (diff_seen); return get_identifier (grp_name); } /* FN is a function that has a complete body. Clone the body as necessary. Returns nonzero if there's no longer any need to process the main body. */ bool maybe_clone_body (tree fn) { tree comdat_group = NULL_TREE; tree clone; tree fns[3]; bool first = true; bool in_charge_parm_used; int idx; bool need_alias = false; /* We only clone constructors and destructors. */ if (!DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)) return 0; /* Emit the DWARF1 abstract instance. */ (*debug_hooks->deferred_inline_function) (fn); in_charge_parm_used = CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fn)) != NULL; fns[0] = NULL_TREE; fns[1] = NULL_TREE; fns[2] = NULL_TREE; /* Look for the complete destructor which may be used to build the delete destructor. */ FOR_EACH_CLONE (clone, fn) if (DECL_NAME (clone) == complete_dtor_identifier || DECL_NAME (clone) == complete_ctor_identifier) fns[1] = clone; else if (DECL_NAME (clone) == base_dtor_identifier || DECL_NAME (clone) == base_ctor_identifier) fns[0] = clone; else if (DECL_NAME (clone) == deleting_dtor_identifier) fns[2] = clone; else gcc_unreachable (); /* Remember if we can't have multiple clones for some reason. We need to check this before we remap local static initializers in clone_body. */ if (!tree_versionable_function_p (fn)) need_alias = true; /* We know that any clones immediately follow FN in the TYPE_METHODS list. */ push_to_top_level (); for (idx = 0; idx < 3; idx++) { tree parm; tree clone_parm; int parmno; bool alias = false; struct pointer_map_t *decl_map; clone = fns[idx]; if (!clone) continue; /* Update CLONE's source position information to match FN's. */ DECL_SOURCE_LOCATION (clone) = DECL_SOURCE_LOCATION (fn); DECL_DECLARED_INLINE_P (clone) = DECL_DECLARED_INLINE_P (fn); DECL_COMDAT (clone) = DECL_COMDAT (fn); DECL_WEAK (clone) = DECL_WEAK (fn); /* We don't copy the comdat group from fn to clone because the assembler name of fn was corrupted by write_mangled_name by adding *INTERNAL* to it. By doing so, it also corrupted the comdat group. */ if (DECL_ONE_ONLY (fn)) DECL_COMDAT_GROUP (clone) = cxx_comdat_group (clone); DECL_SECTION_NAME (clone) = DECL_SECTION_NAME (fn); DECL_USE_TEMPLATE (clone) = DECL_USE_TEMPLATE (fn); DECL_EXTERNAL (clone) = DECL_EXTERNAL (fn); DECL_INTERFACE_KNOWN (clone) = DECL_INTERFACE_KNOWN (fn); DECL_NOT_REALLY_EXTERN (clone) = DECL_NOT_REALLY_EXTERN (fn); TREE_PUBLIC (clone) = TREE_PUBLIC (fn); DECL_VISIBILITY (clone) = DECL_VISIBILITY (fn); DECL_VISIBILITY_SPECIFIED (clone) = DECL_VISIBILITY_SPECIFIED (fn); DECL_DLLIMPORT_P (clone) = DECL_DLLIMPORT_P (fn); DECL_ATTRIBUTES (clone) = copy_list (DECL_ATTRIBUTES (fn)); DECL_DISREGARD_INLINE_LIMITS (clone) = DECL_DISREGARD_INLINE_LIMITS (fn); /* Adjust the parameter names and locations. */ parm = DECL_ARGUMENTS (fn); clone_parm = DECL_ARGUMENTS (clone); /* Update the `this' parameter, which is always first. */ update_cloned_parm (parm, clone_parm, first); parm = DECL_CHAIN (parm); clone_parm = DECL_CHAIN (clone_parm); if (DECL_HAS_IN_CHARGE_PARM_P (fn)) parm = DECL_CHAIN (parm); if (DECL_HAS_VTT_PARM_P (fn)) parm = DECL_CHAIN (parm); if (DECL_HAS_VTT_PARM_P (clone)) clone_parm = DECL_CHAIN (clone_parm); for (; parm; parm = DECL_CHAIN (parm), clone_parm = DECL_CHAIN (clone_parm)) /* Update this parameter. */ update_cloned_parm (parm, clone_parm, first); /* Start processing the function. */ start_preparsed_function (clone, NULL_TREE, SF_PRE_PARSED); /* Tell cgraph if both ctors or both dtors are known to have the same body. */ if (!in_charge_parm_used && fns[0] && idx == 1 && !flag_use_repository && DECL_INTERFACE_KNOWN (fns[0]) && (SUPPORTS_ONE_ONLY || !DECL_WEAK (fns[0])) && (!DECL_ONE_ONLY (fns[0]) || (HAVE_COMDAT_GROUP && DECL_WEAK (fns[0]))) && cgraph_same_body_alias (clone, fns[0])) { alias = true; if (DECL_ONE_ONLY (fns[0])) { /* For comdat base and complete cdtors put them into the same, *[CD]5* comdat group instead of *[CD][12]*. */ comdat_group = cdtor_comdat_group (fns[1], fns[0]); DECL_COMDAT_GROUP (fns[0]) = comdat_group; } } /* Build the delete destructor by calling complete destructor and delete function. */ if (idx == 2) build_delete_destructor_body (clone, fns[1]); else if (alias) /* No need to populate body. */ ; else { /* If we can't have multiple copies of FN (say, because there's a static local initialized with the address of a label), we need to use an alias for the complete variant. */ if (idx == 1 && need_alias) { if (DECL_STRUCT_FUNCTION (fn)->cannot_be_copied_set) sorry (DECL_STRUCT_FUNCTION (fn)->cannot_be_copied_reason, fn); else sorry ("making multiple clones of %qD", fn); } /* Remap the parameters. */ decl_map = pointer_map_create (); for (parmno = 0, parm = DECL_ARGUMENTS (fn), clone_parm = DECL_ARGUMENTS (clone); parm; ++parmno, parm = DECL_CHAIN (parm)) { /* Map the in-charge parameter to an appropriate constant. */ if (DECL_HAS_IN_CHARGE_PARM_P (fn) && parmno == 1) { tree in_charge; in_charge = in_charge_arg_for_name (DECL_NAME (clone)); *pointer_map_insert (decl_map, parm) = in_charge; } else if (DECL_ARTIFICIAL (parm) && DECL_NAME (parm) == vtt_parm_identifier) { /* For a subobject constructor or destructor, the next argument is the VTT parameter. Remap the VTT_PARM from the CLONE to this parameter. */ if (DECL_HAS_VTT_PARM_P (clone)) { DECL_ABSTRACT_ORIGIN (clone_parm) = parm; *pointer_map_insert (decl_map, parm) = clone_parm; clone_parm = DECL_CHAIN (clone_parm); } /* Otherwise, map the VTT parameter to `NULL'. */ else *pointer_map_insert (decl_map, parm) = fold_convert (TREE_TYPE (parm), null_pointer_node); } /* Map other parameters to their equivalents in the cloned function. */ else { *pointer_map_insert (decl_map, parm) = clone_parm; clone_parm = DECL_CHAIN (clone_parm); } } if (targetm.cxx.cdtor_returns_this ()) { parm = DECL_RESULT (fn); clone_parm = DECL_RESULT (clone); *pointer_map_insert (decl_map, parm) = clone_parm; } /* Clone the body. */ clone_body (clone, fn, decl_map); /* Clean up. */ pointer_map_destroy (decl_map); } /* The clone can throw iff the original function can throw. */ cp_function_chain->can_throw = !TREE_NOTHROW (fn); /* Now, expand this function into RTL, if appropriate. */ finish_function (0); BLOCK_ABSTRACT_ORIGIN (DECL_INITIAL (clone)) = DECL_INITIAL (fn); if (alias) { if (expand_or_defer_fn_1 (clone)) emit_associated_thunks (clone); } else expand_or_defer_fn (clone); first = false; } pop_from_top_level (); if (comdat_group) { DECL_COMDAT_GROUP (fns[1]) = comdat_group; if (fns[2]) { struct cgraph_node *base_dtor_node, *deleting_dtor_node; /* If *[CD][12]* dtors go into the *[CD]5* comdat group and dtor is virtual, it goes into the same comdat group as well. */ DECL_COMDAT_GROUP (fns[2]) = comdat_group; base_dtor_node = cgraph_node (fns[0]); deleting_dtor_node = cgraph_node (fns[2]); gcc_assert (base_dtor_node->same_comdat_group == NULL); gcc_assert (deleting_dtor_node->same_comdat_group == NULL); base_dtor_node->same_comdat_group = deleting_dtor_node; deleting_dtor_node->same_comdat_group = base_dtor_node; } } /* We don't need to process the original function any further. */ return 1; }