1 // Copyright (c) 2016 Google Inc.
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/opt/strip_debug_info_pass.h"
16 #include "source/opt/ir_context.h"
17 #include "source/util/string_utils.h"
18
19 namespace spvtools {
20 namespace opt {
21
Process()22 Pass::Status StripDebugInfoPass::Process() {
23 bool uses_non_semantic_info = false;
24 for (auto& inst : context()->module()->extensions()) {
25 const std::string ext_name = inst.GetInOperand(0).AsString();
26 if (ext_name == "SPV_KHR_non_semantic_info") {
27 uses_non_semantic_info = true;
28 }
29 }
30
31 std::vector<Instruction*> to_kill;
32
33 // if we use non-semantic info, it may reference OpString. Do a more
34 // expensive pass checking the uses of the OpString to see if any are
35 // OpExtInst on a non-semantic instruction set. If we're not using the
36 // extension then we can do a simpler pass and kill all debug1 instructions
37 if (uses_non_semantic_info) {
38 for (auto& inst : context()->module()->debugs1()) {
39 switch (inst.opcode()) {
40 case spv::Op::OpString: {
41 analysis::DefUseManager* def_use = context()->get_def_use_mgr();
42
43 // see if this string is used anywhere by a non-semantic instruction
44 bool no_nonsemantic_use =
45 def_use->WhileEachUser(&inst, [def_use](Instruction* use) {
46 if (use->opcode() == spv::Op::OpExtInst) {
47 auto ext_inst_set =
48 def_use->GetDef(use->GetSingleWordInOperand(0u));
49 const std::string extension_name =
50 ext_inst_set->GetInOperand(0).AsString();
51 if (spvtools::utils::starts_with(extension_name,
52 "NonSemantic.")) {
53 // found a non-semantic use, return false as we cannot
54 // remove this OpString
55 return false;
56 }
57 }
58
59 // other instructions can't be a non-semantic use
60 return true;
61 });
62
63 if (no_nonsemantic_use) to_kill.push_back(&inst);
64
65 break;
66 }
67
68 default:
69 to_kill.push_back(&inst);
70 break;
71 }
72 }
73 } else {
74 for (auto& dbg : context()->debugs1()) to_kill.push_back(&dbg);
75 }
76
77 for (auto& dbg : context()->debugs2()) to_kill.push_back(&dbg);
78 for (auto& dbg : context()->debugs3()) to_kill.push_back(&dbg);
79 for (auto& dbg : context()->ext_inst_debuginfo()) to_kill.push_back(&dbg);
80
81 // OpName must come first, since they may refer to other debug instructions.
82 // If they are after the instructions that refer to, then they will be killed
83 // when that instruction is killed, which will lead to a double kill.
84 std::sort(to_kill.begin(), to_kill.end(),
85 [](Instruction* lhs, Instruction* rhs) -> bool {
86 if (lhs->opcode() == spv::Op::OpName &&
87 rhs->opcode() != spv::Op::OpName)
88 return true;
89 return false;
90 });
91
92 bool modified = !to_kill.empty();
93
94 for (auto* inst : to_kill) context()->KillInst(inst);
95
96 // clear OpLine information
97 context()->module()->ForEachInst([&modified](Instruction* inst) {
98 modified |= !inst->dbg_line_insts().empty();
99 inst->dbg_line_insts().clear();
100 });
101
102 if (!get_module()->trailing_dbg_line_info().empty()) {
103 modified = true;
104 get_module()->trailing_dbg_line_info().clear();
105 }
106
107 return modified ? Status::SuccessWithChange : Status::SuccessWithoutChange;
108 }
109
110 } // namespace opt
111 } // namespace spvtools
112