| // |
| // Copyright (C) 2016 LunarG, Inc. |
| // |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions |
| // are met: |
| // |
| // Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // |
| // Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // |
| // Neither the name of 3Dlabs Inc. Ltd. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| // COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| // BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| // LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
| // ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| // POSSIBILITY OF SUCH DAMAGE. |
| // |
| |
| #pragma once |
| |
| #include "../Include/Common.h" |
| #include "reflection.h" |
| #include "localintermediate.h" |
| |
| #include "gl_types.h" |
| |
| #include <list> |
| #include <unordered_set> |
| |
| namespace glslang { |
| |
| // |
| // The traverser: mostly pass through, except |
| // - processing function-call nodes to push live functions onto the stack of functions to process |
| // - processing selection nodes to trim semantically dead code |
| // |
| // This is in the glslang namespace directly so it can be a friend of TReflection. |
| // This can be derived from to implement reflection database traversers or |
| // binding mappers: anything that wants to traverse the live subset of the tree. |
| // |
| |
| class TLiveTraverser : public TIntermTraverser { |
| public: |
| TLiveTraverser(const TIntermediate& i, bool traverseAll = false, |
| bool preVisit = true, bool inVisit = false, bool postVisit = false) : |
| TIntermTraverser(preVisit, inVisit, postVisit), |
| intermediate(i), traverseAll(traverseAll) |
| { } |
| |
| // |
| // Given a function name, find its subroot in the tree, and push it onto the stack of |
| // functions left to process. |
| // |
| void pushFunction(const TString& name) |
| { |
| TIntermSequence& globals = intermediate.getTreeRoot()->getAsAggregate()->getSequence(); |
| for (unsigned int f = 0; f < globals.size(); ++f) { |
| TIntermAggregate* candidate = globals[f]->getAsAggregate(); |
| if (candidate && candidate->getOp() == EOpFunction && candidate->getName() == name) { |
| functions.push_back(candidate); |
| break; |
| } |
| } |
| } |
| |
| typedef std::list<TIntermAggregate*> TFunctionStack; |
| TFunctionStack functions; |
| |
| protected: |
| // To catch which function calls are not dead, and hence which functions must be visited. |
| virtual bool visitAggregate(TVisit, TIntermAggregate* node) |
| { |
| if (!traverseAll) |
| if (node->getOp() == EOpFunctionCall) |
| addFunctionCall(node); |
| |
| return true; // traverse this subtree |
| } |
| |
| // To prune semantically dead paths. |
| virtual bool visitSelection(TVisit /* visit */, TIntermSelection* node) |
| { |
| if (traverseAll) |
| return true; // traverse all code |
| |
| TIntermConstantUnion* constant = node->getCondition()->getAsConstantUnion(); |
| if (constant) { |
| // cull the path that is dead |
| if (constant->getConstArray()[0].getBConst() == true && node->getTrueBlock()) |
| node->getTrueBlock()->traverse(this); |
| if (constant->getConstArray()[0].getBConst() == false && node->getFalseBlock()) |
| node->getFalseBlock()->traverse(this); |
| |
| return false; // don't traverse any more, we did it all above |
| } else |
| return true; // traverse the whole subtree |
| } |
| |
| // Track live functions as well as uniforms, so that we don't visit dead functions |
| // and only visit each function once. |
| void addFunctionCall(TIntermAggregate* call) |
| { |
| // // just use the map to ensure we process each function at most once |
| if (liveFunctions.find(call->getName()) == liveFunctions.end()) { |
| liveFunctions.insert(call->getName()); |
| pushFunction(call->getName()); |
| } |
| } |
| |
| const TIntermediate& intermediate; |
| typedef std::unordered_set<TString> TLiveFunctions; |
| TLiveFunctions liveFunctions; |
| bool traverseAll; |
| |
| private: |
| // prevent copy & copy construct |
| TLiveTraverser(TLiveTraverser&); |
| TLiveTraverser& operator=(TLiveTraverser&); |
| }; |
| |
| } // namespace glslang |