Revert "Allow signposts to take advantage of deferred string substitution"

This reverts commits f9aba9a5af and
035217ff51.

As explained in the original commit message, this didn't have the
intended effect of improving the common LLDB use case, but still
provided a marginal improvement for the places where LLDB creates a
scoped time with a string literal.

The reason for the revert is that this change pulls in the os/signpost.h
header in Signposts.h. The former transitively includes loader.h, which
contains a series of macro defines that conflict with MachO.h. There are
ways to work around that, but Adrian and I concluded that  none of them
are worth the trade-off in complicating Signposts.h even further.

lldb/include/lldb/Utility/Timer.h

@@ -9,16 +9,11 @@
 #ifndef LLDB_UTILITY_TIMER_H
 #define LLDB_UTILITY_TIMER_H
 
-#include "llvm/ADT/ScopeExit.h"
+#include "lldb/lldb-defines.h"
 #include "llvm/Support/Chrono.h"
-#include "llvm/Support/Signposts.h"
 #include <atomic>
 #include <cstdint>
 
-namespace llvm {
-  class SignpostEmitter;
-}
-
 namespace lldb_private {
 class Stream;
 
@@ -81,28 +76,15 @@ private:
   const Timer &operator=(const Timer &) = delete;
 };
 
-llvm::SignpostEmitter &GetSignposts();
-
 } // namespace lldb_private
 
 // Use a format string because LLVM_PRETTY_FUNCTION might not be a string
 // literal.
 #define LLDB_SCOPED_TIMER()                                                    \
   static ::lldb_private::Timer::Category _cat(LLVM_PRETTY_FUNCTION);           \
-  ::lldb_private::Timer _scoped_timer(_cat, "%s", LLVM_PRETTY_FUNCTION);       \
+  ::lldb_private::Timer _scoped_timer(_cat, "%s", LLVM_PRETTY_FUNCTION)
-  SIGNPOST_EMITTER_START_INTERVAL(::lldb_private::GetSignposts(),              \
+#define LLDB_SCOPED_TIMERF(...)                                                \
-                                  &_scoped_timer, "%s", LLVM_PRETTY_FUNCTION); \
-  auto _scoped_signpost = llvm::make_scope_exit([&_scoped_timer]() {           \
-    ::lldb_private::GetSignposts().endInterval(&_scoped_timer);                \
-  })
-
-#define LLDB_SCOPED_TIMERF(FMT, ...)                                           \
   static ::lldb_private::Timer::Category _cat(LLVM_PRETTY_FUNCTION);           \
-  ::lldb_private::Timer _scoped_timer(_cat, FMT, __VA_ARGS__);                 \
+  ::lldb_private::Timer _scoped_timer(_cat, __VA_ARGS__)
-  SIGNPOST_EMITTER_START_INTERVAL(::lldb_private::GetSignposts(),              \
-                                  &_scoped_timer, FMT, __VA_ARGS__);           \
-  auto _scoped_signpost = llvm::make_scope_exit([&_scoped_timer]() {           \
-    ::lldb_private::GetSignposts().endInterval(&_scoped_timer);                \
-  })
 
 #endif // LLDB_UTILITY_TIMER_H

lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp

@@ -21,7 +21,6 @@
 #include "lldb/Core/Section.h"
 #include "lldb/Core/StreamFile.h"
 #include "lldb/Host/Host.h"
-#include "lldb/Host/SafeMachO.h"
 #include "lldb/Symbol/DWARFCallFrameInfo.h"
 #include "lldb/Symbol/LocateSymbolFile.h"
 #include "lldb/Symbol/ObjectFile.h"
@@ -44,6 +43,8 @@
 #include "lldb/Utility/Timer.h"
 #include "lldb/Utility/UUID.h"
 
+#include "lldb/Host/SafeMachO.h"
+
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/MemoryBuffer.h"
@@ -65,48 +66,65 @@
 #include <bitset>
 #include <memory>
 
-#if LLVM_SUPPORT_XCODE_SIGNPOSTS
 // Unfortunately the signpost header pulls in the system MachO header, too.
+#ifdef CPU_TYPE_ARM
 #undef CPU_TYPE_ARM
+#endif
+#ifdef CPU_TYPE_ARM64
 #undef CPU_TYPE_ARM64
+#endif
+#ifdef CPU_TYPE_ARM64_32
 #undef CPU_TYPE_ARM64_32
+#endif
+#ifdef CPU_TYPE_I386
 #undef CPU_TYPE_I386
+#endif
+#ifdef CPU_TYPE_X86_64
 #undef CPU_TYPE_X86_64
-#undef MH_BINDATLOAD
+#endif
-#undef MH_BUNDLE
+#ifdef MH_DYLINKER
-#undef MH_CIGAM
-#undef MH_CIGAM_64
-#undef MH_CORE
-#undef MH_DSYM
-#undef MH_DYLDLINK
-#undef MH_DYLIB
-#undef MH_DYLIB_STUB
 #undef MH_DYLINKER
-#undef MH_DYLINKER
+#endif
-#undef MH_EXECUTE
+#ifdef MH_OBJECT
-#undef MH_FVMLIB
-#undef MH_INCRLINK
-#undef MH_KEXT_BUNDLE
-#undef MH_MAGIC
-#undef MH_MAGIC_64
-#undef MH_NOUNDEFS
 #undef MH_OBJECT
-#undef MH_OBJECT
+#endif
-#undef MH_PRELOAD
+#ifdef LC_VERSION_MIN_MACOSX
-
-#undef LC_BUILD_VERSION
 #undef LC_VERSION_MIN_MACOSX
+#endif
+#ifdef LC_VERSION_MIN_IPHONEOS
 #undef LC_VERSION_MIN_IPHONEOS
+#endif
+#ifdef LC_VERSION_MIN_TVOS
 #undef LC_VERSION_MIN_TVOS
+#endif
+#ifdef LC_VERSION_MIN_WATCHOS
 #undef LC_VERSION_MIN_WATCHOS
-
+#endif
+#ifdef LC_BUILD_VERSION
+#undef LC_BUILD_VERSION
+#endif
+#ifdef PLATFORM_MACOS
 #undef PLATFORM_MACOS
+#endif
+#ifdef PLATFORM_MACCATALYST
 #undef PLATFORM_MACCATALYST
+#endif
+#ifdef PLATFORM_IOS
 #undef PLATFORM_IOS
+#endif
+#ifdef PLATFORM_IOSSIMULATOR
 #undef PLATFORM_IOSSIMULATOR
+#endif
+#ifdef PLATFORM_TVOS
 #undef PLATFORM_TVOS
+#endif
+#ifdef PLATFORM_TVOSSIMULATOR
 #undef PLATFORM_TVOSSIMULATOR
+#endif
+#ifdef PLATFORM_WATCHOS
 #undef PLATFORM_WATCHOS
+#endif
+#ifdef PLATFORM_WATCHOSSIMULATOR
 #undef PLATFORM_WATCHOSSIMULATOR
 #endif
 

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp

@@ -16,6 +16,7 @@
 #include "lldb/Host/FileSystem.h"
 #include "lldb/Utility/RangeMap.h"
 #include "lldb/Utility/RegularExpression.h"
+#include "lldb/Utility/Timer.h"
 
 //#define DEBUG_OSO_DMAP // DO NOT CHECKIN WITH THIS NOT COMMENTED OUT
 #if defined(DEBUG_OSO_DMAP)
@@ -33,9 +34,6 @@
 #include "LogChannelDWARF.h"
 #include "SymbolFileDWARF.h"
 
-// Work around the fact that Timer.h pulls in the system Mach-O headers.
-#include "lldb/Utility/Timer.h"
-
 #include <memory>
 
 using namespace lldb;

lldb/source/Utility/Timer.cpp

@@ -33,8 +33,6 @@ static std::atomic<Timer::Category *> g_categories;
 /// Allows llvm::Timer to emit signposts when supported.
 static llvm::ManagedStatic<llvm::SignpostEmitter> Signposts;
 
-llvm::SignpostEmitter &lldb_private::GetSignposts() { return *Signposts; }
-
 std::atomic<bool> Timer::g_quiet(true);
 std::atomic<unsigned> Timer::g_display_depth(0);
 static std::mutex &GetFileMutex() {
@@ -61,6 +59,7 @@ void Timer::SetQuiet(bool value) { g_quiet = value; }
 
 Timer::Timer(Timer::Category &category, const char *format, ...)
     : m_category(category), m_total_start(std::chrono::steady_clock::now()) {
+  Signposts->startInterval(this, m_category.GetName());
   TimerStack &stack = GetTimerStackForCurrentThread();
 
   stack.push_back(this);
@@ -87,6 +86,8 @@ Timer::~Timer() {
   auto total_dur = stop_time - m_total_start;
   auto timer_dur = total_dur - m_child_duration;
 
+  Signposts->endInterval(this, m_category.GetName());
+
   TimerStack &stack = GetTimerStackForCurrentThread();
   if (g_quiet && stack.size() <= g_display_depth) {
     std::lock_guard<std::mutex> lock(GetFileMutex());

llvm/include/llvm/Config/config.h.cmake

@@ -353,6 +353,9 @@
 /* Define to the default GlobalISel coverage file prefix */
 #cmakedefine LLVM_GISEL_COV_PREFIX "${LLVM_GISEL_COV_PREFIX}"
 
+/* Whether Timers signpost passes in Xcode Instruments */
+#cmakedefine01 LLVM_SUPPORT_XCODE_SIGNPOSTS
+
 #cmakedefine HAVE_PROC_PID_RUSAGE 1
 
 #endif

llvm/include/llvm/Config/llvm-config.h.cmake

@@ -100,8 +100,4 @@
 /* Define if the xar_open() function is supported on this platform. */
 #cmakedefine LLVM_HAVE_LIBXAR ${LLVM_HAVE_LIBXAR}
 
-/* Whether Timers signpost passes in Xcode Instruments */
-#cmakedefine01 LLVM_SUPPORT_XCODE_SIGNPOSTS
-
-
 #endif

llvm/include/llvm/Support/Signposts.h

@@ -17,17 +17,8 @@
 #define LLVM_SUPPORT_SIGNPOSTS_H
 
 #include "llvm/ADT/StringRef.h"
-#include "llvm/Config/llvm-config.h"
 #include <memory>
 
-#if LLVM_SUPPORT_XCODE_SIGNPOSTS
-#include <Availability.h>
-#include <os/signpost.h>
-#endif
-
-#define SIGNPOSTS_AVAILABLE()                                                  \
-  __builtin_available(macos 10.14, iOS 12, tvOS 12, watchOS 5, *)
-
 namespace llvm {
 class SignpostEmitterImpl;
 
@@ -44,33 +35,8 @@ public:
 
   /// Begin a signposted interval for a given object.
   void startInterval(const void *O, StringRef Name);
-
-#if LLVM_SUPPORT_XCODE_SIGNPOSTS
-  os_log_t &getLogger() const;
-  os_signpost_id_t getSignpostForObject(const void *O);
-#endif
-
-  /// A macro to take advantage of the special format string handling
-  /// in the os_signpost API. The format string substitution is
-  /// deferred to the log consumer and done outside of the
-  /// application.
-#if LLVM_SUPPORT_XCODE_SIGNPOSTS
-#define SIGNPOST_EMITTER_START_INTERVAL(SIGNPOST_EMITTER, O, ...)              \
-  do {                                                                         \
-    if ((SIGNPOST_EMITTER).isEnabled())                                        \
-      if (SIGNPOSTS_AVAILABLE())                                               \
-        os_signpost_interval_begin((SIGNPOST_EMITTER).getLogger(),             \
-                                   (SIGNPOST_EMITTER).getSignpostForObject(O), \
-                                   "LLVM Timers", __VA_ARGS__);                \
-  } while (0)
-#else
-#define SIGNPOST_EMITTER_START_INTERVAL(SIGNPOST_EMITTER, O, ...)              \
-  do {                                                                         \
-  } while (0)
-#endif
-
   /// End a signposted interval for a given object.
-  void endInterval(const void *O);
+  void endInterval(const void *O, StringRef Name);
 };
 
 } // end namespace llvm

llvm/lib/Support/Signposts.cpp

@@ -9,14 +9,19 @@
 #include "llvm/Support/Signposts.h"
 #include "llvm/Support/Timer.h"
 
+#include "llvm/Config/config.h"
 #if LLVM_SUPPORT_XCODE_SIGNPOSTS
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/Support/Mutex.h"
-#endif
+#include <Availability.h>
+#include <os/signpost.h>
+#endif // if LLVM_SUPPORT_XCODE_SIGNPOSTS
 
 using namespace llvm;
 
 #if LLVM_SUPPORT_XCODE_SIGNPOSTS
+#define SIGNPOSTS_AVAILABLE()                                                  \
+  __builtin_available(macos 10.14, iOS 12, tvOS 12, watchOS 5, *)
 namespace {
 os_log_t *LogCreator() {
   os_log_t *X = new os_log_t;
@@ -34,13 +39,13 @@ struct LogDeleter {
 namespace llvm {
 class SignpostEmitterImpl {
   using LogPtrTy = std::unique_ptr<os_log_t, LogDeleter>;
+  using LogTy = LogPtrTy::element_type;
 
   LogPtrTy SignpostLog;
   DenseMap<const void *, os_signpost_id_t> Signposts;
   sys::SmartMutex<true> Mutex;
 
-public:
+  LogTy &getLogger() const { return *SignpostLog; }
-  os_log_t &getLogger() const { return *SignpostLog; }
   os_signpost_id_t getSignpostForObject(const void *O) {
     sys::SmartScopedLock<true> Lock(Mutex);
     const auto &I = Signposts.find(O);
@@ -54,6 +59,7 @@ public:
     return Inserted.first->second;
   }
 
+public:
   SignpostEmitterImpl() : SignpostLog(LogCreator()) {}
 
   bool isEnabled() const {
@@ -72,7 +78,7 @@ public:
     }
   }
 
-  void endInterval(const void *O) {
+  void endInterval(const void *O, llvm::StringRef Name) {
     if (isEnabled()) {
       if (SIGNPOSTS_AVAILABLE()) {
         // Both strings used here are required to be constant literal strings.
@@ -118,17 +124,10 @@ void SignpostEmitter::startInterval(const void *O, StringRef Name) {
 #endif // if !HAVE_ANY_SIGNPOST_IMPL
 }
 
-#if HAVE_ANY_SIGNPOST_IMPL
+void SignpostEmitter::endInterval(const void *O, StringRef Name) {
-os_log_t &SignpostEmitter::getLogger() const { return Impl->getLogger(); }
-os_signpost_id_t SignpostEmitter::getSignpostForObject(const void *O) {
-  return Impl->getSignpostForObject(O);
-}
-#endif
-
-void SignpostEmitter::endInterval(const void *O) {
 #if HAVE_ANY_SIGNPOST_IMPL
   if (Impl == nullptr)
     return;
-  Impl->endInterval(O);
+  Impl->endInterval(O, Name);
 #endif // if !HAVE_ANY_SIGNPOST_IMPL
 }

llvm/lib/Support/Timer.cpp

@@ -199,7 +199,7 @@ void Timer::stopTimer() {
   Running = false;
   Time += TimeRecord::getCurrentTime(false);
   Time -= StartTime;
-  Signposts->endInterval(this);
+  Signposts->endInterval(this, getName());
 }
 
 void Timer::clear() {