v8/src/source-position.cc
tebbi 1b320d2039 [cpu-profiler] use new source position information for deoptimization in cpu profiler
The new SourcePosition class allows for precise tracking of source positions including the stack of inlinings. This CL makes the cpu profiler use this new information. Before, the cpu profiler used the deoptimization data to reconstruct the inlining stack. However, optimizing compilers (especially Turbofan) can hoist out checks such that the inlining stack of the deopt reason and the inlining stack of the position the deoptimizer jumps to can be different (the old cpu profiler tests and the ones introduced in this cl produce such situations for turbofan). In this case, relying on the deoptimization info produces paradoxical results, where the reported position is before the function responsible is called. Even worse, https://codereview.chromium.org/2451853002/ combines the precise position with the wrong inlining stack from the deopt info, leading to completely wrong results.

Other changes in this CL:
- DeoptInlinedFrame is no longer needed, because we can compute the correct inlining stack up front.
- I changed the cpu profiler tests back to test situations where deopt checks are hoisted out in Turbofan and made them robust enough to handle the differences between Crankshaft and Turbofan.
- I reversed the order of SourcePosition::InliningStack to make it match the cpu profiler convention.
- I removed CodeDeoptEvent::position, as it is no longer used.

R=alph@chromium.org

BUG=v8:5432

Review-Url: https://codereview.chromium.org/2503393002
Cr-Commit-Position: refs/heads/master@{#41168}
2016-11-22 10:14:59 +00:00

132 lines
4.1 KiB
C++

// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/source-position.h"
#include "src/compilation-info.h"
#include "src/objects-inl.h"
namespace v8 {
namespace internal {
std::ostream& operator<<(std::ostream& out, const SourcePositionInfo& pos) {
Handle<SharedFunctionInfo> function(pos.function);
Handle<Script> script(Script::cast(function->script()));
out << "<";
if (script->name()->IsString()) {
out << String::cast(script->name())->ToCString(DISALLOW_NULLS).get();
} else {
out << "unknown";
}
out << ":" << pos.line + 1 << ":" << pos.column + 1 << ">";
return out;
}
std::ostream& operator<<(std::ostream& out,
const std::vector<SourcePositionInfo>& stack) {
bool first = true;
for (const SourcePositionInfo& pos : stack) {
if (!first) out << " inlined at ";
out << pos;
first = false;
}
return out;
}
std::ostream& operator<<(std::ostream& out, const SourcePosition& pos) {
if (pos.isInlined()) {
out << "<inlined(" << pos.InliningId() << "):";
} else {
out << "<not inlined:";
}
out << pos.ScriptOffset() << ">";
return out;
}
SourcePositionInfo SourcePosition::Info(
Handle<SharedFunctionInfo> function) const {
SourcePositionInfo result(*this, function);
Handle<Script> script(Script::cast(function->script()));
Script::PositionInfo pos;
if (Script::GetPositionInfo(script, ScriptOffset(), &pos,
Script::WITH_OFFSET)) {
result.line = pos.line;
result.column = pos.column;
}
return result;
}
std::vector<SourcePositionInfo> SourcePosition::InliningStack(
CompilationInfo* cinfo) const {
SourcePosition pos = *this;
std::vector<SourcePositionInfo> stack;
while (pos.isInlined()) {
const auto& inl = cinfo->inlined_functions()[pos.InliningId()];
stack.push_back(pos.Info(inl.shared_info));
pos = inl.position.position;
}
stack.push_back(pos.Info(cinfo->shared_info()));
return stack;
}
std::vector<SourcePositionInfo> SourcePosition::InliningStack(
Handle<Code> code) const {
Handle<DeoptimizationInputData> deopt_data(
DeoptimizationInputData::cast(code->deoptimization_data()));
SourcePosition pos = *this;
std::vector<SourcePositionInfo> stack;
while (pos.isInlined()) {
InliningPosition inl =
deopt_data->InliningPositions()->get(pos.InliningId());
Handle<SharedFunctionInfo> function(
deopt_data->GetInlinedFunction(inl.inlined_function_id));
stack.push_back(pos.Info(function));
pos = inl.position;
}
Handle<SharedFunctionInfo> function(
SharedFunctionInfo::cast(deopt_data->SharedFunctionInfo()));
stack.push_back(pos.Info(function));
return stack;
}
void SourcePosition::Print(std::ostream& out,
SharedFunctionInfo* function) const {
Script* script = Script::cast(function->script());
Object* source_name = script->name();
Script::PositionInfo pos;
script->GetPositionInfo(ScriptOffset(), &pos, Script::WITH_OFFSET);
out << "<";
if (source_name->IsString()) {
out << String::cast(source_name)
->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL)
.get();
} else {
out << "unknown";
}
out << ":" << pos.line + 1 << ":" << pos.column + 1 << ">";
}
void SourcePosition::Print(std::ostream& out, Code* code) const {
DeoptimizationInputData* deopt_data =
DeoptimizationInputData::cast(code->deoptimization_data());
if (!isInlined()) {
SharedFunctionInfo* function(
SharedFunctionInfo::cast(deopt_data->SharedFunctionInfo()));
Print(out, function);
} else {
InliningPosition inl = deopt_data->InliningPositions()->get(InliningId());
if (inl.inlined_function_id == -1) {
out << *this;
} else {
SharedFunctionInfo* function =
deopt_data->GetInlinedFunction(inl.inlined_function_id);
Print(out, function);
}
out << " inlined at ";
inl.position.Print(out, code);
}
}
} // namespace internal
} // namespace v8