[clangd] Tracing improvements
Summary:
[clangd] Tracing improvements
Compose JSON using JSONExpr
Allow attaching metadata to spans (and avoid it if tracing is off)
Attach IDs and responses of JSON RPCs to their spans
The downside is that large responses make the trace viewer sluggish.
We should make our responses less huge :-) Or fix trace viewer.
Reviewers: ilya-biryukov
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D40132
llvm-svn: 318928
diff --git a/clang-tools-extra/clangd/ClangdUnit.cpp b/clang-tools-extra/clangd/ClangdUnit.cpp
index 2a9830d..6e01c67 100644
--- a/clang-tools-extra/clangd/ClangdUnit.cpp
+++ b/clang-tools-extra/clangd/ClangdUnit.cpp
@@ -1293,7 +1293,8 @@
// (if there are no other references to it).
OldPreamble.reset();
- trace::Span Tracer(llvm::Twine("Preamble: ") + That->FileName);
+ trace::Span Tracer("Preamble");
+ SPAN_ATTACH(Tracer, "File", That->FileName);
std::vector<DiagWithFixIts> PreambleDiags;
StoreDiagsConsumer PreambleDiagnosticsConsumer(/*ref*/ PreambleDiags);
IntrusiveRefCntPtr<DiagnosticsEngine> PreambleDiagsEngine =
@@ -1342,7 +1343,8 @@
// Compute updated AST.
llvm::Optional<ParsedAST> NewAST;
{
- trace::Span Tracer(llvm::Twine("Build: ") + That->FileName);
+ trace::Span Tracer("Build");
+ SPAN_ATTACH(Tracer, "File", That->FileName);
NewAST = ParsedAST::Build(
std::move(CI), PreambleForAST, SerializedPreambleDecls,
std::move(ContentsBuffer), PCHs, VFS, That->Logger);
diff --git a/clang-tools-extra/clangd/JSONRPCDispatcher.cpp b/clang-tools-extra/clangd/JSONRPCDispatcher.cpp
index 376f833..c1a7ef8 100644
--- a/clang-tools-extra/clangd/JSONRPCDispatcher.cpp
+++ b/clang-tools-extra/clangd/JSONRPCDispatcher.cpp
@@ -59,6 +59,7 @@
Out.log("Attempted to reply to a notification!\n");
return;
}
+ SPAN_ATTACH(tracer(), "Reply", Result);
Out.writeMessage(json::obj{
{"jsonrpc", "2.0"},
{"id", *ID},
@@ -69,6 +70,9 @@
void RequestContext::replyError(ErrorCode code,
const llvm::StringRef &Message) {
Out.log("Error " + Twine(static_cast<int>(code)) + ": " + Message + "\n");
+ SPAN_ATTACH(tracer(), "Error",
+ (json::obj{{"code", static_cast<int>(code)},
+ {"message", Message.str()}}));
if (ID) {
Out.writeMessage(json::obj{
{"jsonrpc", "2.0"},
@@ -82,6 +86,8 @@
void RequestContext::call(StringRef Method, json::Expr &&Params) {
// FIXME: Generate/Increment IDs for every request so that we can get proper
// replies once we need to.
+ SPAN_ATTACH(tracer(), "Call",
+ (json::obj{{"method", Method.str()}, {"params", Params}}));
Out.writeMessage(json::obj{
{"jsonrpc", "2.0"},
{"id", 1},
@@ -104,8 +110,7 @@
llvm::StringRef MethodStr = Method->getValue(MethodStorage);
auto I = Handlers.find(MethodStr);
auto &Handler = I != Handlers.end() ? I->second : UnknownHandler;
- trace::Span Tracer(MethodStr);
- Handler(RequestContext(Out, std::move(ID)), Params);
+ Handler(RequestContext(Out, MethodStr, std::move(ID)), Params);
}
bool JSONRPCDispatcher::call(StringRef Content, JSONOutput &Out) const {
@@ -249,7 +254,6 @@
std::vector<char> JSON(ContentLength + 1, '\0');
llvm::StringRef JSONRef;
{
- trace::Span Tracer("Reading request");
// Now read the JSON. Insert a trailing null byte as required by the
// YAML parser.
In.read(JSON.data(), ContentLength);
diff --git a/clang-tools-extra/clangd/JSONRPCDispatcher.h b/clang-tools-extra/clangd/JSONRPCDispatcher.h
index afc787a..bde5660 100644
--- a/clang-tools-extra/clangd/JSONRPCDispatcher.h
+++ b/clang-tools-extra/clangd/JSONRPCDispatcher.h
@@ -13,6 +13,7 @@
#include "JSONExpr.h"
#include "Logger.h"
#include "Protocol.h"
+#include "Trace.h"
#include "clang/Basic/LLVM.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringMap.h"
@@ -55,8 +56,13 @@
/// Context object passed to handlers to allow replies.
class RequestContext {
public:
- RequestContext(JSONOutput &Out, llvm::Optional<json::Expr> ID)
- : Out(Out), ID(std::move(ID)) {}
+ RequestContext(JSONOutput &Out, StringRef Method,
+ llvm::Optional<json::Expr> ID)
+ : Out(Out), ID(std::move(ID)),
+ Tracer(llvm::make_unique<trace::Span>(Method)) {
+ if (this->ID)
+ SPAN_ATTACH(tracer(), "ID", *this->ID);
+ }
/// Sends a successful reply.
void reply(json::Expr &&Result);
@@ -65,9 +71,12 @@
/// Sends a request to the client.
void call(llvm::StringRef Method, json::Expr &&Params);
+ trace::Span &tracer() { return *Tracer; }
+
private:
JSONOutput &Out;
llvm::Optional<json::Expr> ID;
+ std::unique_ptr<trace::Span> Tracer;
};
/// Main JSONRPC entry point. This parses the JSONRPC "header" and calls the
diff --git a/clang-tools-extra/clangd/Trace.cpp b/clang-tools-extra/clangd/Trace.cpp
index 1607327..6a51d04 100644
--- a/clang-tools-extra/clangd/Trace.cpp
+++ b/clang-tools-extra/clangd/Trace.cpp
@@ -27,13 +27,17 @@
// Perhaps we should replace this by something that disturbs performance less.
class Tracer {
public:
- Tracer(raw_ostream &Out)
- : Out(Out), Sep(""), Start(std::chrono::system_clock::now()) {
+ Tracer(raw_ostream &Out, bool Pretty)
+ : Out(Out), Sep(""), Start(std::chrono::system_clock::now()),
+ JSONFormat(Pretty ? "{0:2}" : "{0}") {
// The displayTimeUnit must be ns to avoid low-precision overlap
// calculations!
Out << R"({"displayTimeUnit":"ns","traceEvents":[)"
<< "\n";
- rawEvent("M", R"("name": "process_name", "args":{"name":"clangd"})");
+ rawEvent("M", json::obj{
+ {"name", "process_name"},
+ {"args", json::obj{{"name", "clangd"}}},
+ });
}
~Tracer() {
@@ -43,7 +47,7 @@
// Record an event on the current thread. ph, pid, tid, ts are set.
// Contents must be a list of the other JSON key/values.
- template <typename T> void event(StringRef Phase, const T &Contents) {
+ void event(StringRef Phase, json::obj &&Contents) {
uint64_t TID = get_threadid();
std::lock_guard<std::mutex> Lock(Mu);
// If we haven't already, emit metadata describing this thread.
@@ -51,24 +55,26 @@
SmallString<32> Name;
get_thread_name(Name);
if (!Name.empty()) {
- rawEvent(
- "M",
- formatv(
- R"("tid": {0}, "name": "thread_name", "args":{"name":"{1}"})",
- TID, StringRef(&Name[0], Name.size())));
+ rawEvent("M", json::obj{
+ {"tid", TID},
+ {"name", "thread_name"},
+ {"args", json::obj{{"name", Name}}},
+ });
}
}
- rawEvent(Phase, formatv(R"("ts":{0}, "tid":{1}, {2})", timestamp(), TID,
- Contents));
+ Contents["ts"] = timestamp();
+ Contents["tid"] = TID;
+ rawEvent(Phase, std::move(Contents));
}
private:
// Record an event. ph and pid are set.
// Contents must be a list of the other JSON key/values.
- template <typename T>
- void rawEvent(StringRef Phase, const T &Contents) /*REQUIRES(Mu)*/ {
+ void rawEvent(StringRef Phase, json::obj &&Event) /*REQUIRES(Mu)*/ {
// PID 0 represents the clangd process.
- Out << Sep << R"({"pid":0, "ph":")" << Phase << "\", " << Contents << "}";
+ Event["pid"] = 0;
+ Event["ph"] = Phase;
+ Out << Sep << formatv(JSONFormat, json::Expr(std::move(Event)));
Sep = ",\n";
}
@@ -82,14 +88,15 @@
const char *Sep /*GUARDED_BY(Mu)*/;
DenseSet<uint64_t> ThreadsWithMD /*GUARDED_BY(Mu)*/;
const sys::TimePoint<> Start;
+ const char *JSONFormat;
};
static Tracer *T = nullptr;
} // namespace
-std::unique_ptr<Session> Session::create(raw_ostream &OS) {
+std::unique_ptr<Session> Session::create(raw_ostream &OS, bool Pretty) {
assert(!T && "A session is already active");
- T = new Tracer(OS);
+ T = new Tracer(OS, Pretty);
return std::unique_ptr<Session>(new Session());
}
@@ -101,19 +108,25 @@
void log(const Twine &Message) {
if (!T)
return;
- T->event("i", formatv(R"("name":"{0}")", yaml::escape(Message.str())));
+ T->event("i", json::obj{
+ {"name", "Log"},
+ {"args", json::obj{{"Message", Message.str()}}},
+ });
}
-Span::Span(const Twine &Text) {
+Span::Span(std::string Name) {
if (!T)
return;
- T->event("B", formatv(R"("name":"{0}")", yaml::escape(Text.str())));
+ T->event("B", json::obj{{"name", std::move(Name)}});
+ Args = llvm::make_unique<json::obj>();
}
Span::~Span() {
if (!T)
return;
- T->event("E", R"("_":0)" /* Dummy property to ensure valid JSON */);
+ if (!Args)
+ Args = llvm::make_unique<json::obj>();
+ T->event("E", Args ? json::obj{{"args", std::move(*Args)}} : json::obj{});
}
} // namespace trace
diff --git a/clang-tools-extra/clangd/Trace.h b/clang-tools-extra/clangd/Trace.h
index 746e48a..436fc83 100644
--- a/clang-tools-extra/clangd/Trace.h
+++ b/clang-tools-extra/clangd/Trace.h
@@ -21,6 +21,7 @@
#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_TRACE_H_
#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_TRACE_H_
+#include "JSONExpr.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/raw_ostream.h"
@@ -35,7 +36,8 @@
class Session {
public:
// Starts a sessions capturing trace events and writing Trace Event JSON.
- static std::unique_ptr<Session> create(llvm::raw_ostream &OS);
+ static std::unique_ptr<Session> create(llvm::raw_ostream &OS,
+ bool Pretty = false);
~Session();
private:
@@ -46,14 +48,30 @@
void log(const llvm::Twine &Name);
// Records an event whose duration is the lifetime of the Span object.
+//
+// Arbitrary JSON metadata can be attached while this span is active:
+// SPAN_ATTACH(MySpan, "Payload", SomeJSONExpr);
+// SomeJSONExpr is evaluated and copied only if actually needed.
class Span {
public:
- Span(const llvm::Twine &Name);
+ Span(std::string Name);
~Span();
+ // Returns mutable span metadata if this span is interested.
+ // Prefer to use SPAN_ATTACH rather than accessing this directly.
+ json::obj *args() { return Args.get(); }
+
private:
+ std::unique_ptr<json::obj> Args;
};
+#define SPAN_ATTACH(S, Name, Expr) \
+ do { \
+ if ((S).args() != nullptr) { \
+ (*((S).args()))[(Name)] = (Expr); \
+ } \
+ } while (0)
+
} // namespace trace
} // namespace clangd
} // namespace clang
diff --git a/clang-tools-extra/clangd/tool/ClangdMain.cpp b/clang-tools-extra/clangd/tool/ClangdMain.cpp
index e209fe0..7dde227 100644
--- a/clang-tools-extra/clangd/tool/ClangdMain.cpp
+++ b/clang-tools-extra/clangd/tool/ClangdMain.cpp
@@ -124,7 +124,7 @@
TraceFile.reset();
llvm::errs() << "Error while opening trace file: " << EC.message();
} else {
- TraceSession = trace::Session::create(*TraceStream);
+ TraceSession = trace::Session::create(*TraceStream, PrettyPrint);
}
}