llvm-project/clang/unittests/Support/TimeProfilerTest.cpp
Kadir Cetinkaya df9a14d7bb
Reapply "[NFC] Explicitly pass a VFS when creating DiagnosticsEngine (#115852)"
This reverts commit a1153cd6fedd4c906a9840987934ca4712e34cb2 with fixes
to lldb breakages.

Fixes https://github.com/llvm/llvm-project/issues/117145.
2024-11-21 14:55:30 +01:00

349 lines
11 KiB
C++

//===- unittests/Support/TimeProfilerTest.cpp -----------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Frontend/FrontendActions.h"
#include "clang/Lex/PreprocessorOptions.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/JSON.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/TimeProfiler.h"
#include "llvm/Support/VirtualFileSystem.h"
#include <stack>
#include "gtest/gtest.h"
#include <tuple>
using namespace clang;
using namespace llvm;
namespace {
// Should be called before testing.
void setupProfiler() {
timeTraceProfilerInitialize(/*TimeTraceGranularity=*/0, "test",
/*TimeTraceVerbose=*/true);
}
// Should be called after `compileFromString()`.
// Returns profiler's JSON dump.
std::string teardownProfiler() {
SmallVector<char, 1024> SmallVec;
raw_svector_ostream OS(SmallVec);
timeTraceProfilerWrite(OS);
timeTraceProfilerCleanup();
return OS.str().str();
}
// Returns true if code compiles successfully.
// We only parse AST here. This is enough for constexpr evaluation.
bool compileFromString(StringRef Code, StringRef Standard, StringRef File,
llvm::StringMap<std::string> Headers = {}) {
llvm::IntrusiveRefCntPtr<llvm::vfs::InMemoryFileSystem> FS(
new llvm::vfs::InMemoryFileSystem());
FS->addFile(File, 0, MemoryBuffer::getMemBuffer(Code));
for (const auto &Header : Headers) {
FS->addFile(Header.getKey(), 0,
MemoryBuffer::getMemBuffer(Header.getValue()));
}
llvm::IntrusiveRefCntPtr<FileManager> Files(
new FileManager(FileSystemOptions(), FS));
CompilerInstance Compiler;
Compiler.createDiagnostics(Files->getVirtualFileSystem());
Compiler.setFileManager(Files.get());
auto Invocation = std::make_shared<CompilerInvocation>();
std::vector<const char *> Args = {Standard.data(), File.data()};
CompilerInvocation::CreateFromArgs(*Invocation, Args,
Compiler.getDiagnostics());
Compiler.setInvocation(std::move(Invocation));
class TestFrontendAction : public ASTFrontendAction {
private:
std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
StringRef InFile) override {
return std::make_unique<ASTConsumer>();
}
} Action;
return Compiler.ExecuteAction(Action);
}
std::string GetMetadata(json::Object *Event) {
std::string M;
llvm::raw_string_ostream OS(M);
if (json::Object *Args = Event->getObject("args")) {
if (auto Detail = Args->getString("detail"))
OS << Detail;
// Use only filename to not include os-specific path separators.
if (auto File = Args->getString("file"))
OS << (M.empty() ? "" : ", ") << llvm::sys::path::filename(*File);
if (auto Line = Args->getInteger("line"))
OS << ":" << *Line;
}
return M;
}
// Returns pretty-printed trace graph.
std::string buildTraceGraph(StringRef Json) {
struct EventRecord {
int64_t TimestampBegin;
int64_t TimestampEnd;
std::string Name;
std::string Metadata;
};
std::vector<EventRecord> Events;
// Parse `EventRecord`s from JSON dump.
Expected<json::Value> Root = json::parse(Json);
if (!Root)
return "";
for (json::Value &TraceEventValue :
*Root->getAsObject()->getArray("traceEvents")) {
json::Object *TraceEventObj = TraceEventValue.getAsObject();
int64_t TimestampBegin = TraceEventObj->getInteger("ts").value_or(0);
int64_t TimestampEnd =
TimestampBegin + TraceEventObj->getInteger("dur").value_or(0);
std::string Name = TraceEventObj->getString("name").value_or("").str();
std::string Metadata = GetMetadata(TraceEventObj);
// Source events are asynchronous events and may not perfectly nest the
// synchronous events. Skip testing them.
if (Name == "Source")
continue;
// This is a "summary" event, like "Total PerformPendingInstantiations",
// skip it
if (TimestampBegin == 0)
continue;
Events.emplace_back(
EventRecord{TimestampBegin, TimestampEnd, Name, Metadata});
}
// There can be nested events that are very fast, for example:
// {"name":"EvaluateAsBooleanCondition",... ,"ts":2380,"dur":1}
// {"name":"EvaluateAsRValue",... ,"ts":2380,"dur":1}
// Therefore we should reverse the events list, so that events that have
// started earlier are first in the list.
// Then do a stable sort, we need it for the trace graph.
std::reverse(Events.begin(), Events.end());
std::stable_sort(
Events.begin(), Events.end(), [](const auto &lhs, const auto &rhs) {
return std::make_pair(lhs.TimestampBegin, -lhs.TimestampEnd) <
std::make_pair(rhs.TimestampBegin, -rhs.TimestampEnd);
});
std::stringstream Stream;
// Write a newline for better testing with multiline string literal.
Stream << "\n";
// Keep the current event stack.
std::stack<const EventRecord *> EventStack;
for (const auto &Event : Events) {
// Pop every event in the stack until meeting the parent event.
while (!EventStack.empty()) {
bool InsideCurrentEvent =
Event.TimestampBegin >= EventStack.top()->TimestampBegin &&
Event.TimestampEnd <= EventStack.top()->TimestampEnd;
if (!InsideCurrentEvent)
EventStack.pop();
else
break;
}
EventStack.push(&Event);
// Write indentaion, name, detail, newline.
for (size_t i = 1; i < EventStack.size(); ++i) {
Stream << "| ";
}
Stream.write(Event.Name.data(), Event.Name.size());
if (!Event.Metadata.empty()) {
Stream << " (";
Stream.write(Event.Metadata.data(), Event.Metadata.size());
Stream << ")";
}
Stream << "\n";
}
return Stream.str();
}
} // namespace
TEST(TimeProfilerTest, ConstantEvaluationCxx20) {
std::string Code = R"(
void print(double value);
namespace slow_namespace {
consteval double slow_func() {
double d = 0.0;
for (int i = 0; i < 100; ++i) { // 8th line
d += i; // 9th line
}
return d;
}
} // namespace slow_namespace
void slow_test() {
constexpr auto slow_value = slow_namespace::slow_func(); // 17th line
print(slow_namespace::slow_func()); // 18th line
print(slow_value);
}
int slow_arr[12 + 34 * 56 + // 22nd line
static_cast<int>(slow_namespace::slow_func())]; // 23rd line
constexpr int slow_init_list[] = {1, 1, 2, 3, 5, 8, 13, 21}; // 25th line
)";
setupProfiler();
ASSERT_TRUE(compileFromString(Code, "-std=c++20", "test.cc"));
std::string Json = teardownProfiler();
ASSERT_EQ(R"(
Frontend (test.cc)
| ParseDeclarationOrFunctionDefinition (test.cc:2:1)
| ParseDeclarationOrFunctionDefinition (test.cc:6:1)
| | ParseFunctionDefinition (slow_func)
| | | EvaluateAsRValue (<test.cc:8:21>)
| | | EvaluateForOverflow (<test.cc:8:21, col:25>)
| | | EvaluateForOverflow (<test.cc:8:30, col:32>)
| | | EvaluateAsRValue (<test.cc:9:14>)
| | | EvaluateForOverflow (<test.cc:9:9, col:14>)
| | | isPotentialConstantExpr (slow_namespace::slow_func)
| | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)
| | | | EvaluateAsRValue (<test.cc:8:21, col:25>)
| | | EvaluateAsBooleanCondition (<test.cc:8:21, col:25>)
| | | | EvaluateAsRValue (<test.cc:8:21, col:25>)
| ParseDeclarationOrFunctionDefinition (test.cc:16:1)
| | ParseFunctionDefinition (slow_test)
| | | EvaluateAsInitializer (slow_value)
| | | EvaluateAsConstantExpr (<test.cc:17:33, col:59>)
| | | EvaluateAsConstantExpr (<test.cc:18:11, col:37>)
| ParseDeclarationOrFunctionDefinition (test.cc:22:1)
| | EvaluateAsConstantExpr (<test.cc:23:31, col:57>)
| | EvaluateAsRValue (<test.cc:22:14, line:23:58>)
| ParseDeclarationOrFunctionDefinition (test.cc:25:1)
| | EvaluateAsInitializer (slow_init_list)
| PerformPendingInstantiations
)",
buildTraceGraph(Json));
}
TEST(TimeProfilerTest, ClassTemplateInstantiations) {
std::string Code = R"(
template<class T>
struct S
{
void foo() {}
void bar();
};
template struct S<double>; // explicit instantiation of S<double>
void user() {
S<int> a; // implicit instantiation of S<int>
S<float>* b;
b->foo(); // implicit instatiation of S<float> and S<float>::foo()
}
)";
setupProfiler();
ASSERT_TRUE(compileFromString(Code, "-std=c++20", "test.cc"));
std::string Json = teardownProfiler();
ASSERT_EQ(R"(
Frontend (test.cc)
| ParseClass (S)
| InstantiateClass (S<double>, test.cc:9)
| InstantiateFunction (S<double>::foo, test.cc:5)
| ParseDeclarationOrFunctionDefinition (test.cc:11:5)
| | ParseFunctionDefinition (user)
| | | InstantiateClass (S<int>, test.cc:3)
| | | InstantiateClass (S<float>, test.cc:3)
| | | DeferInstantiation (S<float>::foo)
| PerformPendingInstantiations
| | InstantiateFunction (S<float>::foo, test.cc:5)
)",
buildTraceGraph(Json));
}
TEST(TimeProfilerTest, TemplateInstantiations) {
std::string B_H = R"(
template <typename T>
T fooC(T t) {
return T();
}
template <typename T>
constexpr T fooB(T t) {
return fooC(t);
}
#define MacroTemp(x) template <typename T> void foo##x(T) { T(); }
)";
std::string A_H = R"(
#include "b.h"
MacroTemp(MTA)
template <typename T>
void fooA(T t) { fooB(t); fooMTA(t); }
)";
std::string Code = R"(
#include "a.h"
void user() { fooA(0); }
)";
setupProfiler();
ASSERT_TRUE(compileFromString(Code, "-std=c++20", "test.cc",
/*Headers=*/{{"a.h", A_H}, {"b.h", B_H}}));
std::string Json = teardownProfiler();
ASSERT_EQ(R"(
Frontend (test.cc)
| ParseFunctionDefinition (fooC)
| ParseFunctionDefinition (fooB)
| ParseFunctionDefinition (fooMTA)
| ParseFunctionDefinition (fooA)
| ParseDeclarationOrFunctionDefinition (test.cc:3:5)
| | ParseFunctionDefinition (user)
| | | DeferInstantiation (fooA<int>)
| PerformPendingInstantiations
| | InstantiateFunction (fooA<int>, a.h:7)
| | | InstantiateFunction (fooB<int>, b.h:8)
| | | | DeferInstantiation (fooC<int>)
| | | DeferInstantiation (fooMTA<int>)
| | | InstantiateFunction (fooC<int>, b.h:3)
| | | InstantiateFunction (fooMTA<int>, a.h:4)
)",
buildTraceGraph(Json));
}
TEST(TimeProfilerTest, ConstantEvaluationC99) {
std::string Code = R"(
struct {
short quantval[4]; // 3rd line
} value;
)";
setupProfiler();
ASSERT_TRUE(compileFromString(Code, "-std=c99", "test.c"));
std::string Json = teardownProfiler();
ASSERT_EQ(R"(
Frontend (test.c)
| ParseDeclarationOrFunctionDefinition (test.c:2:1)
| | isIntegerConstantExpr (<test.c:3:18>)
| | EvaluateKnownConstIntCheckOverflow (<test.c:3:18>)
| PerformPendingInstantiations
)",
buildTraceGraph(Json));
}