source/fuzz/uniform_buffer_element_descriptor.cpp

   1 // Copyright (c) 2019 Google LLC
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 #include "source/fuzz/uniform_buffer_element_descriptor.h"
  16
  17 #include <algorithm>
  18
  19 namespace spvtools {
  20 namespace fuzz {
  21
  22 protobufs::UniformBufferElementDescriptor MakeUniformBufferElementDescriptor(
  23     uint32_t descriptor_set, uint32_t binding,
  24     std::vector<uint32_t>&& indices) {
  25   protobufs::UniformBufferElementDescriptor result;
  26   result.set_descriptor_set(descriptor_set);
  27   result.set_binding(binding);
  28   for (auto index : indices) {
  29     result.add_index(index);
  30   }
  31   return result;
  32 }
  33
  34 bool UniformBufferElementDescriptorEquals::operator()(
  35     const protobufs::UniformBufferElementDescriptor* first,
  36     const protobufs::UniformBufferElementDescriptor* second) const {
  37   return first->descriptor_set() == second->descriptor_set() &&
  38          first->binding() == second->binding() &&
  39          first->index().size() == second->index().size() &&
  40          std::equal(first->index().begin(), first->index().end(),
  41                     second->index().begin());
  42 }
  43
  44 opt::Instruction* FindUniformVariable(
  45     const protobufs::UniformBufferElementDescriptor&
  46         uniform_buffer_element_descriptor,
  47     opt::IRContext* context, bool check_unique) {
  48   opt::Instruction* result = nullptr;
  49
  50   for (auto& inst : context->types_values()) {
  51     // Consider all global variables with uniform storage class.
  52     if (inst.opcode() != spv::Op::OpVariable) {
  53       continue;
  54     }
  55     if (spv::StorageClass(inst.GetSingleWordInOperand(0)) !=
  56         spv::StorageClass::Uniform) {
  57       continue;
  58     }
  59
  60     // Determine whether the variable is decorated with a descriptor set
  61     // matching that in |uniform_buffer_element|.
  62     bool descriptor_set_matches = false;
  63     context->get_decoration_mgr()->ForEachDecoration(
  64         inst.result_id(), uint32_t(spv::Decoration::DescriptorSet),
  65         [&descriptor_set_matches, &uniform_buffer_element_descriptor](
  66             const opt::Instruction& decoration_inst) {
  67           const uint32_t kDescriptorSetOperandIndex = 2;
  68           if (decoration_inst.GetSingleWordInOperand(
  69                   kDescriptorSetOperandIndex) ==
  70               uniform_buffer_element_descriptor.descriptor_set()) {
  71             descriptor_set_matches = true;
  72           }
  73         });
  74     if (!descriptor_set_matches) {
  75       // Descriptor set does not match.
  76       continue;
  77     }
  78
  79     // Determine whether the variable is decorated with a binding matching that
  80     // in |uniform_buffer_element|.
  81     bool binding_matches = false;
  82     context->get_decoration_mgr()->ForEachDecoration(
  83         inst.result_id(), uint32_t(spv::Decoration::Binding),
  84         [&binding_matches, &uniform_buffer_element_descriptor](
  85             const opt::Instruction& decoration_inst) {
  86           const uint32_t kBindingOperandIndex = 2;
  87           if (decoration_inst.GetSingleWordInOperand(kBindingOperandIndex) ==
  88               uniform_buffer_element_descriptor.binding()) {
  89             binding_matches = true;
  90           }
  91         });
  92     if (!binding_matches) {
  93       // Binding does not match.
  94       continue;
  95     }
  96
  97     // This instruction is a uniform variable with the right descriptor set and
  98     // binding.
  99     if (!check_unique) {
 100       // If we aren't checking uniqueness, return it.
 101       return &inst;
 102     }
 103
 104     if (result) {
 105       // More than one uniform variable is decorated with the given descriptor
 106       // set and binding. This means the fact is ambiguous.
 107       return nullptr;
 108     }
 109     result = &inst;
 110   }
 111
 112   // We get here either if no match was found, or if |check_unique| holds and
 113   // exactly one match was found.
 114   assert(result == nullptr || check_unique);
 115   return result;
 116 }
 117
 118 }  // namespace fuzz
 119 }  // namespace spvtools