1 // Copyright (c) 2020 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 #ifndef SOURCE_FUZZ_TRANSFORMATION_ACCESS_CHAIN_H_ 16 #define SOURCE_FUZZ_TRANSFORMATION_ACCESS_CHAIN_H_ 17 18 #include <utility> 19 20 #include "source/fuzz/protobufs/spirvfuzz_protobufs.h" 21 #include "source/fuzz/transformation.h" 22 #include "source/fuzz/transformation_context.h" 23 #include "source/opt/ir_context.h" 24 25 namespace spvtools { 26 namespace fuzz { 27 28 class TransformationAccessChain : public Transformation { 29 public: 30 explicit TransformationAccessChain( 31 const protobufs::TransformationAccessChain& message); 32 33 TransformationAccessChain( 34 uint32_t fresh_id, uint32_t pointer_id, 35 const std::vector<uint32_t>& index_id, 36 const protobufs::InstructionDescriptor& instruction_to_insert_before, 37 const std::vector<std::pair<uint32_t, uint32_t>>& fresh_ids_for_clamping = 38 {}); 39 40 // - |message_.fresh_id| must be fresh. 41 // - |message_.instruction_to_insert_before| must identify an instruction 42 // before which it is legitimate to insert an OpAccessChain instruction. 43 // - |message_.pointer_id| must be a result id with pointer type that is 44 // available (according to dominance rules) at the insertion point. 45 // - The pointer must not be OpConstantNull or OpUndef. 46 // - |message_.index_id| must be a sequence of ids of 32-bit integers 47 // such that it is possible to walk the pointee type of 48 // |message_.pointer_id| using these indices. 49 // - All indices used to access a struct must be OpConstant. 50 // - The indices used to index non-struct composites will be clamped to be 51 // in bound. Enough fresh ids must be given in 52 // |message_.fresh_id_for_clamping| to perform clamping (2 for 53 // each index accessing a non-struct). This requires the bool type and 54 // a constant of value (bound - 1) to be declared in the module. 55 // - If type t is the final type reached by walking these indices, the module 56 // must include an instruction "OpTypePointer SC %t" where SC is the storage 57 // class associated with |message_.pointer_id|. 58 bool IsApplicable( 59 opt::IRContext* ir_context, 60 const TransformationContext& transformation_context) const override; 61 62 // Adds an instruction of the form: 63 // |message_.fresh_id| = OpAccessChain %ptr |message_.index_id| 64 // where %ptr is the result if of an instruction declaring a pointer to the 65 // type reached by walking the pointee type of |message_.pointer_id| using 66 // the indices in |message_.index_id|, and with the same storage class as 67 // |message_.pointer_id|. 68 // 69 // For each of the indices traversing non-struct composites, two clamping 70 // instructions are added using ids in |message_.fresh_id_for_clamping|. 71 // 72 // If the fact manager in |transformation_context| reports that 73 // |message_.pointer_id| has an irrelevant pointee value, then the fact that 74 // |message_.fresh_id| (the result of the access chain) also has an irrelevant 75 // pointee value is also recorded. 76 void Apply(opt::IRContext* ir_context, 77 TransformationContext* transformation_context) const override; 78 79 std::unordered_set<uint32_t> GetFreshIds() const override; 80 81 protobufs::Transformation ToMessage() const override; 82 83 private: 84 // Returns {false, 0} in each of the following cases: 85 // - |index_id| does not correspond to a 32-bit integer constant 86 // - the object being indexed is not a composite type 87 // - the constant at |index_id| is out of bounds. 88 // Otherwise, returns {true, value}, where value is the value of the constant 89 // at |index_id|. 90 std::pair<bool, uint32_t> GetIndexValue(opt::IRContext* ir_context, 91 uint32_t index_id, 92 uint32_t object_type_id) const; 93 94 // Returns true if |index_id| corresponds, in the given context, to a 32-bit 95 // integer which can be used to index an object of the type specified by 96 // |object_type_id|. Returns false otherwise. 97 static bool ValidIndexToComposite(opt::IRContext* ir_context, 98 uint32_t index_id, uint32_t object_type_id); 99 100 protobufs::TransformationAccessChain message_; 101 }; 102 103 } // namespace fuzz 104 } // namespace spvtools 105 106 #endif // SOURCE_FUZZ_TRANSFORMATION_ACCESS_CHAIN_H_ 107