1 // Copyright (c) 2020 Vasyl Teliman
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/fuzzer_pass_add_copy_memory.h"
16
17 #include "source/fuzz/fuzzer_context.h"
18 #include "source/fuzz/fuzzer_util.h"
19 #include "source/fuzz/instruction_descriptor.h"
20 #include "source/fuzz/transformation_add_copy_memory.h"
21
22 namespace spvtools {
23 namespace fuzz {
24
FuzzerPassAddCopyMemory(opt::IRContext * ir_context,TransformationContext * transformation_context,FuzzerContext * fuzzer_context,protobufs::TransformationSequence * transformations,bool ignore_inapplicable_transformations)25 FuzzerPassAddCopyMemory::FuzzerPassAddCopyMemory(
26 opt::IRContext* ir_context, TransformationContext* transformation_context,
27 FuzzerContext* fuzzer_context,
28 protobufs::TransformationSequence* transformations,
29 bool ignore_inapplicable_transformations)
30 : FuzzerPass(ir_context, transformation_context, fuzzer_context,
31 transformations, ignore_inapplicable_transformations) {}
32
Apply()33 void FuzzerPassAddCopyMemory::Apply() {
34 ForEachInstructionWithInstructionDescriptor(
35 [this](opt::Function* function, opt::BasicBlock* block,
36 opt::BasicBlock::iterator inst_it,
37 const protobufs::InstructionDescriptor& instruction_descriptor) {
38 // Check that we can insert an OpCopyMemory before this instruction.
39 if (!fuzzerutil::CanInsertOpcodeBeforeInstruction(spv::Op::OpCopyMemory,
40 inst_it)) {
41 return;
42 }
43
44 if (!GetFuzzerContext()->ChoosePercentage(
45 GetFuzzerContext()->GetChanceOfAddingCopyMemory())) {
46 return;
47 }
48
49 // Get all instructions available before |inst_it| according to the
50 // domination rules.
51 auto instructions = FindAvailableInstructions(
52 function, block, inst_it,
53 TransformationAddCopyMemory::IsInstructionSupported);
54
55 if (instructions.empty()) {
56 return;
57 }
58
59 const auto* inst =
60 instructions[GetFuzzerContext()->RandomIndex(instructions)];
61
62 // Decide whether to create global or local variable.
63 auto storage_class = GetFuzzerContext()->ChooseEven()
64 ? spv::StorageClass::Private
65 : spv::StorageClass::Function;
66
67 auto pointee_type_id = fuzzerutil::GetPointeeTypeIdFromPointerType(
68 GetIRContext(), inst->type_id());
69
70 // Create a pointer type with |storage_class| if needed.
71 FindOrCreatePointerType(pointee_type_id, storage_class);
72
73 ApplyTransformation(TransformationAddCopyMemory(
74 instruction_descriptor, GetFuzzerContext()->GetFreshId(),
75 inst->result_id(), storage_class,
76 FindOrCreateZeroConstant(pointee_type_id, false)));
77 });
78 }
79
80 } // namespace fuzz
81 } // namespace spvtools
82