tools/gn/deps_iterator.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "tools/gn/deps_iterator.h"
   6
   7 #include "tools/gn/target.h"
   8
   9 DepsIterator::DepsIterator(const Target* t) : current_index_(0) {
  10   vect_stack_[0] = &t->public_deps();
  11   vect_stack_[1] = &t->private_deps();
  12   vect_stack_[2] = &t->data_deps();
  13
  14   if (vect_stack_[0]->empty())
  15     Advance();
  16 }
  17
  18 // Iterate over the public and private linked deps, but not the data deps.
  19 DepsIterator::DepsIterator(const Target* t, LinkedOnly) : current_index_(0) {
  20   vect_stack_[0] = &t->public_deps();
  21   vect_stack_[1] = &t->private_deps();
  22   vect_stack_[2] = NULL;
  23
  24   if (vect_stack_[0]->empty())
  25     Advance();
  26 }
  27
  28 // Advance to the next position. This assumes there are more vectors.
  29 //
  30 // For internal use, this function tolerates an initial index equal to the
  31 // length of the current vector. In this case, it will advance to the next
  32 // one.
  33 void DepsIterator::Advance() {
  34   DCHECK(vect_stack_[0]);
  35
  36   current_index_++;
  37   if (current_index_ >= vect_stack_[0]->size()) {
  38     // Advance to next vect. Shift the elements left by one.
  39     vect_stack_[0] = vect_stack_[1];
  40     vect_stack_[1] = vect_stack_[2];
  41     vect_stack_[2] = NULL;
  42
  43     current_index_ = 0;
  44
  45     if (vect_stack_[0] && vect_stack_[0]->empty())
  46       Advance();
  47   }
  48 }