SPIRV-Tools/source/fuzz/call_graph.cpp

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// Copyright (c) 2020 Google LLC
//
// 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/fuzz/call_graph.h"
#include <queue>
namespace spvtools {
namespace fuzz {
CallGraph::CallGraph(opt::IRContext* context) {
// Initialize function in-degree and call graph edges to 0 and empty.
for (auto& function : *context->module()) {
function_in_degree_[function.result_id()] = 0;
call_graph_edges_[function.result_id()] = std::set<uint32_t>();
}
// Consider every function.
for (auto& function : *context->module()) {
// Avoid considering the same callee of this function multiple times by
// recording known callees.
std::set<uint32_t> known_callees;
// Consider every function call instruction in every block.
for (auto& block : function) {
for (auto& instruction : block) {
if (instruction.opcode() != SpvOpFunctionCall) {
continue;
}
// Get the id of the function being called.
uint32_t callee = instruction.GetSingleWordInOperand(0);
if (known_callees.count(callee)) {
// We have already considered a call to this function - ignore it.
continue;
}
// Increase the callee's in-degree and add an edge to the call graph.
function_in_degree_[callee]++;
call_graph_edges_[function.result_id()].insert(callee);
// Mark the callee as 'known'.
known_callees.insert(callee);
}
}
}
}
void CallGraph::PushDirectCallees(uint32_t function_id,
std::queue<uint32_t>* queue) const {
for (auto callee : GetDirectCallees(function_id)) {
queue->push(callee);
}
}
std::set<uint32_t> CallGraph::GetIndirectCallees(uint32_t function_id) const {
std::set<uint32_t> result;
std::queue<uint32_t> queue;
PushDirectCallees(function_id, &queue);
while (!queue.empty()) {
auto next = queue.front();
queue.pop();
if (result.count(next)) {
continue;
}
result.insert(next);
PushDirectCallees(next, &queue);
}
return result;
}
} // namespace fuzz
} // namespace spvtools