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_replace_parameter_with_global.h"
16
17 #include <numeric>
18 #include <vector>
19
20 #include "source/fuzz/fuzzer_context.h"
21 #include "source/fuzz/fuzzer_util.h"
22 #include "source/fuzz/transformation_replace_parameter_with_global.h"
23
24 namespace spvtools {
25 namespace fuzz {
26
FuzzerPassReplaceParameterWithGlobal(opt::IRContext * ir_context,TransformationContext * transformation_context,FuzzerContext * fuzzer_context,protobufs::TransformationSequence * transformations)27 FuzzerPassReplaceParameterWithGlobal::FuzzerPassReplaceParameterWithGlobal(
28 opt::IRContext* ir_context, TransformationContext* transformation_context,
29 FuzzerContext* fuzzer_context,
30 protobufs::TransformationSequence* transformations)
31 : FuzzerPass(ir_context, transformation_context, fuzzer_context,
32 transformations) {}
33
Apply()34 void FuzzerPassReplaceParameterWithGlobal::Apply() {
35 for (const auto& function : *GetIRContext()->module()) {
36 if (fuzzerutil::FunctionIsEntryPoint(GetIRContext(),
37 function.result_id())) {
38 continue;
39 }
40
41 if (!GetFuzzerContext()->ChoosePercentage(
42 GetFuzzerContext()->GetChanceOfReplacingParametersWithGlobals())) {
43 continue;
44 }
45
46 auto params =
47 fuzzerutil::GetParameters(GetIRContext(), function.result_id());
48
49 // Make sure at least one parameter can be replaced. Also checks that the
50 // function has at least one parameter.
51 if (std::none_of(params.begin(), params.end(),
52 [this](const opt::Instruction* param) {
53 return TransformationReplaceParameterWithGlobal::
54 IsParameterTypeSupported(GetIRContext(),
55 param->type_id());
56 })) {
57 continue;
58 }
59
60 // Select id of a parameter to replace.
61 const opt::Instruction* replaced_param;
62 uint32_t param_type_id;
63 do {
64 replaced_param = GetFuzzerContext()->RemoveAtRandomIndex(¶ms);
65 param_type_id = replaced_param->type_id();
66 assert(param_type_id && "Parameter has invalid type");
67 } while (
68 !TransformationReplaceParameterWithGlobal::IsParameterTypeSupported(
69 GetIRContext(), param_type_id));
70
71 assert(replaced_param && "Unable to find a parameter to replace");
72
73 // Make sure type id for the global variable exists in the module.
74 FindOrCreatePointerType(replaced_param->type_id(), SpvStorageClassPrivate);
75
76 // Make sure initializer for the global variable exists in the module.
77 FindOrCreateZeroConstant(replaced_param->type_id(), false);
78
79 ApplyTransformation(TransformationReplaceParameterWithGlobal(
80 GetFuzzerContext()->GetFreshId(), replaced_param->result_id(),
81 GetFuzzerContext()->GetFreshId()));
82 }
83 }
84
85 } // namespace fuzz
86 } // namespace spvtools
87