SPIRV-Tools/source/opt/strip_debug_info_pass.cpp
Marius Hillenbrand 1ed847f438
Fix endianness of string literals (#4622)
* Fix endianness of string literals

To get correct and consistent encoding and decoding of string literals
on big-endian platforms, use spvtools::utils::MakeString and MakeVector
(or wrapper functions) consistently for handling string literals.

- add variant of MakeVector that encodes a string literal into an
  existing vector of words
- add variants of MakeString
- add a wrapper spvDecodeLiteralStringOperand in source/
- fix wrapper Operand::AsString to use MakeString (source/opt)
- remove Operand::AsCString as broken and unused
- add a variant of GetOperandAs for string literals (source/val)
... and apply those wrappers throughout the code.

Fixes  #149

* Extend round trip test for StringLiterals to flip word order

In the encoding/decoding roundtrip tests for string literals, include
a case that flips byte order in words after encoding and then checks for
successful decoding. That is, on a little-endian host flip to big-endian
byte order and then decode, and vice versa.

* BinaryParseTest.InstructionWithStringOperand: also flip byte order

Test binary parsing of string operands both with the host's and with the
reversed byte order.
2021-12-08 12:01:26 -05:00

111 lines
3.9 KiB
C++

// Copyright (c) 2016 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "source/opt/strip_debug_info_pass.h"
#include "source/opt/ir_context.h"
#include "source/util/string_utils.h"
namespace spvtools {
namespace opt {
Pass::Status StripDebugInfoPass::Process() {
bool uses_non_semantic_info = false;
for (auto& inst : context()->module()->extensions()) {
const std::string ext_name = inst.GetInOperand(0).AsString();
if (ext_name == "SPV_KHR_non_semantic_info") {
uses_non_semantic_info = true;
}
}
std::vector<Instruction*> to_kill;
// if we use non-semantic info, it may reference OpString. Do a more
// expensive pass checking the uses of the OpString to see if any are
// OpExtInst on a non-semantic instruction set. If we're not using the
// extension then we can do a simpler pass and kill all debug1 instructions
if (uses_non_semantic_info) {
for (auto& inst : context()->module()->debugs1()) {
switch (inst.opcode()) {
case SpvOpString: {
analysis::DefUseManager* def_use = context()->get_def_use_mgr();
// see if this string is used anywhere by a non-semantic instruction
bool no_nonsemantic_use =
def_use->WhileEachUser(&inst, [def_use](Instruction* use) {
if (use->opcode() == SpvOpExtInst) {
auto ext_inst_set =
def_use->GetDef(use->GetSingleWordInOperand(0u));
const std::string extension_name =
ext_inst_set->GetInOperand(0).AsString();
if (spvtools::utils::starts_with(extension_name,
"NonSemantic.")) {
// found a non-semantic use, return false as we cannot
// remove this OpString
return false;
}
}
// other instructions can't be a non-semantic use
return true;
});
if (no_nonsemantic_use) to_kill.push_back(&inst);
break;
}
default:
to_kill.push_back(&inst);
break;
}
}
} else {
for (auto& dbg : context()->debugs1()) to_kill.push_back(&dbg);
}
for (auto& dbg : context()->debugs2()) to_kill.push_back(&dbg);
for (auto& dbg : context()->debugs3()) to_kill.push_back(&dbg);
for (auto& dbg : context()->ext_inst_debuginfo()) to_kill.push_back(&dbg);
// OpName must come first, since they may refer to other debug instructions.
// If they are after the instructions that refer to, then they will be killed
// when that instruction is killed, which will lead to a double kill.
std::sort(to_kill.begin(), to_kill.end(),
[](Instruction* lhs, Instruction* rhs) -> bool {
if (lhs->opcode() == SpvOpName && rhs->opcode() != SpvOpName)
return true;
return false;
});
bool modified = !to_kill.empty();
for (auto* inst : to_kill) context()->KillInst(inst);
// clear OpLine information
context()->module()->ForEachInst([&modified](Instruction* inst) {
modified |= !inst->dbg_line_insts().empty();
inst->dbg_line_insts().clear();
});
if (!get_module()->trailing_dbg_line_info().empty()) {
modified = true;
get_module()->trailing_dbg_line_info().clear();
}
return modified ? Status::SuccessWithChange : Status::SuccessWithoutChange;
}
} // namespace opt
} // namespace spvtools