/* Copyright (c) 2015-2017 The Khronos Group Inc.
 * Copyright (c) 2015-2017 Valve Corporation
 * Copyright (c) 2015-2017 LunarG, Inc.
 * Copyright (C) 2015-2017 Google 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.
 *
 * Author: Chris Forbes <chrisf@ijw.co.nz>
 */
#ifndef VULKAN_SHADER_VALIDATION_H
#define VULKAN_SHADER_VALIDATION_H

// A forward iterator over spirv instructions. Provides easy access to len, opcode, and content words
// without the caller needing to care too much about the physical SPIRV module layout.
struct spirv_inst_iter {
    std::vector<uint32_t>::const_iterator zero;
    std::vector<uint32_t>::const_iterator it;

    uint32_t len() {
        auto result = *it >> 16;
        assert(result > 0);
        return result;
    }

    uint32_t opcode() { return *it & 0x0ffffu; }

    uint32_t const &word(unsigned n) {
        assert(n < len());
        return it[n];
    }

    uint32_t offset() { return (uint32_t)(it - zero); }

    spirv_inst_iter() {}

    spirv_inst_iter(std::vector<uint32_t>::const_iterator zero, std::vector<uint32_t>::const_iterator it) : zero(zero), it(it) {}

    bool operator==(spirv_inst_iter const &other) { return it == other.it; }

    bool operator!=(spirv_inst_iter const &other) { return it != other.it; }

    spirv_inst_iter operator++(int) {  // x++
        spirv_inst_iter ii = *this;
        it += len();
        return ii;
    }

    spirv_inst_iter operator++() {  // ++x;
        it += len();
        return *this;
    }

    // The iterator and the value are the same thing.
    spirv_inst_iter &operator*() { return *this; }
    spirv_inst_iter const &operator*() const { return *this; }
};

struct shader_module {
    // The spirv image itself
    std::vector<uint32_t> words;
    // A mapping of <id> to the first word of its def. this is useful because walking type
    // trees, constant expressions, etc requires jumping all over the instruction stream.
    std::unordered_map<unsigned, unsigned> def_index;
    bool has_valid_spirv;

    shader_module(VkShaderModuleCreateInfo const *pCreateInfo)
        : words((uint32_t *)pCreateInfo->pCode, (uint32_t *)pCreateInfo->pCode + pCreateInfo->codeSize / sizeof(uint32_t)),
          def_index(),
          has_valid_spirv(true) {
        build_def_index();
    }

    shader_module() : has_valid_spirv(false) {}

    // Expose begin() / end() to enable range-based for
    spirv_inst_iter begin() const { return spirv_inst_iter(words.begin(), words.begin() + 5); }  // First insn
    spirv_inst_iter end() const { return spirv_inst_iter(words.begin(), words.end()); }          // Just past last insn
    // Given an offset into the module, produce an iterator there.
    spirv_inst_iter at(unsigned offset) const { return spirv_inst_iter(words.begin(), words.begin() + offset); }

    // Gets an iterator to the definition of an id
    spirv_inst_iter get_def(unsigned id) const {
        auto it = def_index.find(id);
        if (it == def_index.end()) {
            return end();
        }
        return at(it->second);
    }

    void build_def_index();
};

bool validate_and_capture_pipeline_shader_state(layer_data *dev_data, PIPELINE_STATE *pPipeline);
bool validate_compute_pipeline(layer_data *dev_data, PIPELINE_STATE *pPipeline);
typedef std::pair<unsigned, unsigned> descriptor_slot_t;
bool PreCallValidateCreateShaderModule(layer_data *dev_data, VkShaderModuleCreateInfo const *pCreateInfo, bool *spirv_valid);

#endif //VULKAN_SHADER_VALIDATION_H