// Copyright (c) 2015-2016 The Khronos Group Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include "source/val/basic_block.h"

#include <algorithm>

#include <vector>

namespace spvtools {

namespace val {

BasicBlock::BasicBlock(uint32_t label_id)

    : id_(label_id),

      immediate_dominator_(nullptr),

      immediate_structural_dominator_(nullptr),

      immediate_structural_post_dominator_(nullptr),

      predecessors_(),

      successors_(),

      type_(0),

      reachable_(false),

      structurally_reachable_(false),

      label_(nullptr),

      terminator_(nullptr) {}

void BasicBlock::SetImmediateDominator(BasicBlock* dom_block) {

  immediate_dominator_ = dom_block;

}

void BasicBlock::SetImmediateStructuralDominator(BasicBlock* dom_block) {

  immediate_structural_dominator_ = dom_block;

}

void BasicBlock::SetImmediateStructuralPostDominator(BasicBlock* pdom_block) {

  immediate_structural_post_dominator_ = pdom_block;

}

const BasicBlock* BasicBlock::immediate_dominator() const {

  return immediate_dominator_;

}

const BasicBlock* BasicBlock::immediate_structural_dominator() const {

  return immediate_structural_dominator_;

}

const BasicBlock* BasicBlock::immediate_structural_post_dominator() const {

  return immediate_structural_post_dominator_;

}

BasicBlock* BasicBlock::immediate_dominator() { return immediate_dominator_; }

BasicBlock* BasicBlock::immediate_structural_dominator() {

  return immediate_structural_dominator_;

}

BasicBlock* BasicBlock::immediate_structural_post_dominator() {

  return immediate_structural_post_dominator_;

}

void BasicBlock::RegisterSuccessors(

    const std::vector<BasicBlock*>& next_blocks) {

  for (auto& block : next_blocks) {

    block->predecessors_.push_back(this);

    successors_.push_back(block);

    // Register structural successors/predecessors too.

    block->structural_predecessors_.push_back(this);

    structural_successors_.push_back(block);

  }

}

bool BasicBlock::dominates(const BasicBlock& other) const {

  return (this == &other) ||

         !(other.dom_end() ==

           std::find(other.dom_begin(), other.dom_end(), this));

}

bool BasicBlock::structurally_dominates(const BasicBlock& other) const {

  return (this == &other) || !(other.structural_dom_end() ==

                               std::find(other.structural_dom_begin(),

                                         other.structural_dom_end(), this));

}

bool BasicBlock::structurally_postdominates(const BasicBlock& other) const {

  return (this == &other) || !(other.structural_pdom_end() ==

                               std::find(other.structural_pdom_begin(),

                                         other.structural_pdom_end(), this));

}

BasicBlock::DominatorIterator::DominatorIterator() : current_(nullptr) {}

BasicBlock::DominatorIterator::DominatorIterator(

    const BasicBlock* block,

    std::function<const BasicBlock*(const BasicBlock*)> dominator_func)

    : current_(block), dom_func_(dominator_func) {}

BasicBlock::DominatorIterator& BasicBlock::DominatorIterator::operator++() {

  if (current_ == dom_func_(current_)) {

    current_ = nullptr;

  } else {

    current_ = dom_func_(current_);

  }

  return *this;

}

const BasicBlock::DominatorIterator BasicBlock::dom_begin() const {

  return DominatorIterator(

      this, [](const BasicBlock* b) { return b->immediate_dominator(); });

}

BasicBlock::DominatorIterator BasicBlock::dom_begin() {

  return DominatorIterator(

      this, [](const BasicBlock* b) { return b->immediate_dominator(); });

}

const BasicBlock::DominatorIterator BasicBlock::dom_end() const {

  return DominatorIterator();

}

BasicBlock::DominatorIterator BasicBlock::dom_end() {

  return DominatorIterator();

}

const BasicBlock::DominatorIterator BasicBlock::structural_dom_begin() const {

  return DominatorIterator(this, [](const BasicBlock* b) {

    return b->immediate_structural_dominator();

  });

}

BasicBlock::DominatorIterator BasicBlock::structural_dom_begin() {

  return DominatorIterator(this, [](const BasicBlock* b) {

    return b->immediate_structural_dominator();

  });

}

const BasicBlock::DominatorIterator BasicBlock::structural_dom_end() const {

  return DominatorIterator();

}

BasicBlock::DominatorIterator BasicBlock::structural_dom_end() {

  return DominatorIterator();

}

const BasicBlock::DominatorIterator BasicBlock::structural_pdom_begin() const {

  return DominatorIterator(this, [](const BasicBlock* b) {

    return b->immediate_structural_post_dominator();

  });

}

BasicBlock::DominatorIterator BasicBlock::structural_pdom_begin() {

  return DominatorIterator(this, [](const BasicBlock* b) {

    return b->immediate_structural_post_dominator();

  });

}

const BasicBlock::DominatorIterator BasicBlock::structural_pdom_end() const {

  return DominatorIterator();

}

BasicBlock::DominatorIterator BasicBlock::structural_pdom_end() {

  return DominatorIterator();

}

bool operator==(const BasicBlock::DominatorIterator& lhs,

                const BasicBlock::DominatorIterator& rhs) {

  return lhs.current_ == rhs.current_;

}

bool operator!=(const BasicBlock::DominatorIterator& lhs,

                const BasicBlock::DominatorIterator& rhs) {

  return !(lhs == rhs);

}

const BasicBlock*& BasicBlock::DominatorIterator::operator*() {

  return current_;

}

}  // namespace val

}  // namespace spvtools