1/* Iterator routines for manipulating GENERIC tree statement list. -*- C++ -*-
2   Copyright (C) 2003-2022 Free Software Foundation, Inc.
3   Contributed by Andrew MacLeod  <amacleod@redhat.com>
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 3, or (at your option)
10any later version.
11
12GCC is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING3.  If not see
19<http://www.gnu.org/licenses/>.  */
20
21
22/* This file is dependent upon the implementation of tree's. It provides an
23   abstract interface to the tree objects such that if all tree creation and
24   manipulations are done through this interface, we can easily change the
25   implementation of tree's, and not impact other code.  */
26
27#ifndef GCC_TREE_ITERATOR_H
28#define GCC_TREE_ITERATOR_H 1
29
30/* Iterator object for GENERIC or GIMPLE TREE statements.  */
31
32struct tree_stmt_iterator {
33  struct tree_statement_list_node *ptr;
34  tree container;
35
36  /* No need for user-defined constructors, the implicit definitions (or
37     aggregate initialization) are fine.  */
38
39  bool operator== (tree_stmt_iterator b) const
40    { return b.ptr == ptr && b.container == container; }
41  bool operator!= (tree_stmt_iterator b) const { return !(*this == b); }
42  tree_stmt_iterator &operator++ () { ptr = ptr->next; return *this; }
43  tree_stmt_iterator &operator-- () { ptr = ptr->prev; return *this; }
44  tree_stmt_iterator operator++ (int)
45    { tree_stmt_iterator x = *this; ++*this; return x; }
46  tree_stmt_iterator operator-- (int)
47    { tree_stmt_iterator x = *this; --*this; return x; }
48  tree &operator* () { return ptr->stmt; }
49  tree operator* () const { return ptr->stmt; }
50};
51
52static inline tree_stmt_iterator
53tsi_start (tree t)
54{
55  tree_stmt_iterator i;
56
57  i.ptr = STATEMENT_LIST_HEAD (t);
58  i.container = t;
59
60  return i;
61}
62
63static inline tree_stmt_iterator
64tsi_last (tree t)
65{
66  tree_stmt_iterator i;
67
68  i.ptr = STATEMENT_LIST_TAIL (t);
69  i.container = t;
70
71  return i;
72}
73
74static inline bool
75tsi_end_p (tree_stmt_iterator i)
76{
77  return i.ptr == NULL;
78}
79
80static inline bool
81tsi_one_before_end_p (tree_stmt_iterator i)
82{
83  return i.ptr != NULL && i.ptr->next == NULL;
84}
85
86static inline void
87tsi_next (tree_stmt_iterator *i)
88{
89  ++(*i);
90}
91
92static inline void
93tsi_prev (tree_stmt_iterator *i)
94{
95  --(*i);
96}
97
98static inline tree *
99tsi_stmt_ptr (tree_stmt_iterator i)
100{
101  return &(*i);
102}
103
104static inline tree
105tsi_stmt (tree_stmt_iterator i)
106{
107  return *i;
108}
109
110/* Make tree_stmt_iterator work as a C++ range, e.g.
111   for (tree stmt : tsi_range (stmt_list)) { ... }  */
112class tsi_range
113{
114  tree t;
115 public:
116  tsi_range (tree t): t(t) { }
117  tree_stmt_iterator begin() const { return tsi_start (t); }
118  tree_stmt_iterator end() const { return { nullptr, t }; }
119};
120
121enum tsi_iterator_update
122{
123  TSI_NEW_STMT,		/* Only valid when single statement is added, move
124			   iterator to it.  */
125  TSI_SAME_STMT,	/* Leave the iterator at the same statement.  */
126  TSI_CHAIN_START,	/* Only valid when chain of statements is added, move
127			   iterator to the first statement in the chain.  */
128  TSI_CHAIN_END,	/* Only valid when chain of statements is added, move
129			   iterator to the last statement in the chain.  */
130  TSI_CONTINUE_LINKING	/* Move iterator to whatever position is suitable for
131			   linking other statements/chains of statements in
132			   the same direction.  */
133};
134
135extern void tsi_link_before (tree_stmt_iterator *, tree,
136			     enum tsi_iterator_update);
137extern void tsi_link_after (tree_stmt_iterator *, tree,
138			    enum tsi_iterator_update);
139
140extern void tsi_delink (tree_stmt_iterator *);
141
142extern tree alloc_stmt_list (void);
143extern void free_stmt_list (tree);
144extern void append_to_statement_list (tree, tree *);
145extern void append_to_statement_list_force (tree, tree *);
146extern tree expr_first (tree);
147extern tree expr_last (tree);
148extern tree expr_single (tree);
149
150#endif /* GCC_TREE_ITERATOR_H  */
151