1 // Copyright (c) 2019 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 #include "source/fuzz/fuzzer_pass_adjust_function_controls.h"
16
17 #include "source/fuzz/transformation_set_function_control.h"
18
19 namespace spvtools {
20 namespace fuzz {
21
FuzzerPassAdjustFunctionControls(opt::IRContext * ir_context,TransformationContext * transformation_context,FuzzerContext * fuzzer_context,protobufs::TransformationSequence * transformations)22 FuzzerPassAdjustFunctionControls::FuzzerPassAdjustFunctionControls(
23 opt::IRContext* ir_context, TransformationContext* transformation_context,
24 FuzzerContext* fuzzer_context,
25 protobufs::TransformationSequence* transformations)
26 : FuzzerPass(ir_context, transformation_context, fuzzer_context,
27 transformations) {}
28
Apply()29 void FuzzerPassAdjustFunctionControls::Apply() {
30 // Consider every function in the module.
31 for (auto& function : *GetIRContext()->module()) {
32 // Randomly decide whether to adjust this function's controls.
33 if (GetFuzzerContext()->ChoosePercentage(
34 GetFuzzerContext()->GetChanceOfAdjustingFunctionControl())) {
35 // Grab the function control mask for the function in its present form.
36 uint32_t existing_function_control_mask =
37 function.DefInst().GetSingleWordInOperand(0);
38
39 // For the new mask, we first randomly select one of three basic masks:
40 // None, Inline or DontInline. These are always valid (and are mutually
41 // exclusive).
42 std::vector<uint32_t> basic_function_control_masks = {
43 SpvFunctionControlMaskNone, SpvFunctionControlInlineMask,
44 SpvFunctionControlDontInlineMask};
45 uint32_t new_function_control_mask =
46 basic_function_control_masks[GetFuzzerContext()->RandomIndex(
47 basic_function_control_masks)];
48
49 // We now consider the Pure and Const mask bits. If these are already
50 // set on the function then it's OK to keep them, but also interesting
51 // to consider dropping them, so we decide randomly in each case.
52 for (auto mask_bit :
53 {SpvFunctionControlPureMask, SpvFunctionControlConstMask}) {
54 if ((existing_function_control_mask & mask_bit) &&
55 GetFuzzerContext()->ChooseEven()) {
56 new_function_control_mask |= mask_bit;
57 }
58 }
59
60 // Create and add a transformation.
61 TransformationSetFunctionControl transformation(
62 function.DefInst().result_id(), new_function_control_mask);
63 ApplyTransformation(transformation);
64 }
65 }
66 }
67
68 } // namespace fuzz
69 } // namespace spvtools
70