1 // Copyright (c) 2020 André Perez Maselco
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_inline_functions.h"
16
17 #include "source/fuzz/fuzzer_util.h"
18 #include "source/fuzz/instruction_descriptor.h"
19 #include "source/fuzz/transformation_inline_function.h"
20 #include "source/fuzz/transformation_split_block.h"
21
22 namespace spvtools {
23 namespace fuzz {
24
FuzzerPassInlineFunctions(opt::IRContext * ir_context,TransformationContext * transformation_context,FuzzerContext * fuzzer_context,protobufs::TransformationSequence * transformations)25 FuzzerPassInlineFunctions::FuzzerPassInlineFunctions(
26 opt::IRContext* ir_context, TransformationContext* transformation_context,
27 FuzzerContext* fuzzer_context,
28 protobufs::TransformationSequence* transformations)
29 : FuzzerPass(ir_context, transformation_context, fuzzer_context,
30 transformations) {}
31
Apply()32 void FuzzerPassInlineFunctions::Apply() {
33 // |function_call_instructions| are the instructions that will be inlined.
34 // First, they will be collected and then do the inlining in another loop.
35 // This avoids changing the module while it is being inspected.
36 std::vector<opt::Instruction*> function_call_instructions;
37
38 for (auto& function : *GetIRContext()->module()) {
39 for (auto& block : function) {
40 for (auto& instruction : block) {
41 if (!GetFuzzerContext()->ChoosePercentage(
42 GetFuzzerContext()->GetChanceOfInliningFunction())) {
43 continue;
44 }
45
46 // |instruction| must be suitable for inlining.
47 if (!TransformationInlineFunction::IsSuitableForInlining(
48 GetIRContext(), &instruction)) {
49 continue;
50 }
51
52 function_call_instructions.push_back(&instruction);
53 }
54 }
55 }
56
57 // Once the function calls have been collected, it's time to actually create
58 // and apply the inlining transformations.
59 for (auto& function_call_instruction : function_call_instructions) {
60 // If |function_call_instruction| is not the penultimate instruction in its
61 // block or its block termination instruction is not OpBranch, then try to
62 // split |function_call_block| such that the conditions are met.
63 auto* function_call_block =
64 GetIRContext()->get_instr_block(function_call_instruction);
65 if ((function_call_instruction != &*--function_call_block->tail() ||
66 function_call_block->terminator()->opcode() != SpvOpBranch) &&
67 !MaybeApplyTransformation(TransformationSplitBlock(
68 MakeInstructionDescriptor(GetIRContext(),
69 function_call_instruction->NextNode()),
70 GetFuzzerContext()->GetFreshId()))) {
71 continue;
72 }
73
74 auto* called_function = fuzzerutil::FindFunction(
75 GetIRContext(), function_call_instruction->GetSingleWordInOperand(0));
76
77 // Mapping the called function instructions.
78 std::map<uint32_t, uint32_t> result_id_map;
79 for (auto& called_function_block : *called_function) {
80 // The called function entry block label will not be inlined.
81 if (&called_function_block != &*called_function->entry()) {
82 result_id_map[called_function_block.GetLabelInst()->result_id()] =
83 GetFuzzerContext()->GetFreshId();
84 }
85
86 for (auto& instruction_to_inline : called_function_block) {
87 // The instructions are mapped to fresh ids.
88 if (instruction_to_inline.HasResultId()) {
89 result_id_map[instruction_to_inline.result_id()] =
90 GetFuzzerContext()->GetFreshId();
91 }
92 }
93 }
94
95 // Applies the inline function transformation.
96 ApplyTransformation(TransformationInlineFunction(
97 function_call_instruction->result_id(), result_id_map));
98 }
99 }
100
101 } // namespace fuzz
102 } // namespace spvtools
103