gcc/tree-iterator.h

   1 /* Iterator routines for manipulating GENERIC tree statement list. -*- C++ -*-
   2    Copyright (C) 2003-2021 Free Software Foundation, Inc.
   3    Contributed by Andrew MacLeod  <amacleod@redhat.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along 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
  32 struct 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
  52 static inline tree_stmt_iterator
  53 tsi_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
  63 static inline tree_stmt_iterator
  64 tsi_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
  74 static inline bool
  75 tsi_end_p (tree_stmt_iterator i)
  76 {
  77   return i.ptr == NULL;
  78 }
  79
  80 static inline bool
  81 tsi_one_before_end_p (tree_stmt_iterator i)
  82 {
  83   return i.ptr != NULL && i.ptr->next == NULL;
  84 }
  85
  86 static inline void
  87 tsi_next (tree_stmt_iterator *i)
  88 {
  89   ++(*i);
  90 }
  91
  92 static inline void
  93 tsi_prev (tree_stmt_iterator *i)
  94 {
  95   --(*i);
  96 }
  97
  98 static inline tree *
  99 tsi_stmt_ptr (tree_stmt_iterator i)
 100 {
 101   return &(*i);
 102 }
 103
 104 static inline tree
 105 tsi_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)) { ... }  */
 112 class 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
 121 enum 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
 135 extern void tsi_link_before (tree_stmt_iterator *, tree,
 136                              enum tsi_iterator_update);
 137 extern void tsi_link_after (tree_stmt_iterator *, tree,
 138                             enum tsi_iterator_update);
 139
 140 extern void tsi_delink (tree_stmt_iterator *);
 141
 142 extern tree alloc_stmt_list (void);
 143 extern void free_stmt_list (tree);
 144 extern void append_to_statement_list (tree, tree *);
 145 extern void append_to_statement_list_force (tree, tree *);
 146 extern tree expr_first (tree);
 147 extern tree expr_last (tree);
 148 extern tree expr_single (tree);
 149
 150 #endif /* GCC_TREE_ITERATOR_H  */