llvm/lib/Support/Signposts.cpp

   1 //===-- Signposts.cpp - Interval debug annotations ------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "llvm/Support/Signposts.h"
  10 #include "llvm/ADT/StringRef.h"
  11 #include "llvm/Config/config.h"
  12
  13 #if LLVM_SUPPORT_XCODE_SIGNPOSTS
  14 #include "llvm/ADT/DenseMap.h"
  15 #include "llvm/Support/Mutex.h"
  16 #include <Availability.h>
  17 #include <os/signpost.h>
  18 #endif // if LLVM_SUPPORT_XCODE_SIGNPOSTS
  19
  20 using namespace llvm;
  21
  22 #if LLVM_SUPPORT_XCODE_SIGNPOSTS
  23 #define SIGNPOSTS_AVAILABLE()                                                  \
  24   __builtin_available(macos 10.14, iOS 12, tvOS 12, watchOS 5, *)
  25 namespace {
  26 os_log_t *LogCreator() {
  27   os_log_t *X = new os_log_t;
  28   *X = os_log_create("org.llvm.signposts", "toolchain");
  29   return X;
  30 }
  31 struct LogDeleter {
  32   void operator()(os_log_t *X) const {
  33     os_release(*X);
  34     delete X;
  35   }
  36 };
  37 } // end anonymous namespace
  38
  39 namespace llvm {
  40 class SignpostEmitterImpl {
  41   using LogPtrTy = std::unique_ptr<os_log_t, LogDeleter>;
  42   using LogTy = LogPtrTy::element_type;
  43
  44   LogPtrTy SignpostLog;
  45   DenseMap<const void *, os_signpost_id_t> Signposts;
  46   sys::SmartMutex<true> Mutex;
  47
  48   LogTy &getLogger() const { return *SignpostLog; }
  49   os_signpost_id_t getSignpostForObject(const void *O) {
  50     sys::SmartScopedLock<true> Lock(Mutex);
  51     const auto &I = Signposts.find(O);
  52     if (I != Signposts.end())
  53       return I->second;
  54     os_signpost_id_t ID = {};
  55     if (SIGNPOSTS_AVAILABLE()) {
  56       ID = os_signpost_id_make_with_pointer(getLogger(), O);
  57     }
  58     const auto &Inserted = Signposts.insert(std::make_pair(O, ID));
  59     return Inserted.first->second;
  60   }
  61
  62 public:
  63   SignpostEmitterImpl() : SignpostLog(LogCreator()) {}
  64
  65   bool isEnabled() const {
  66     if (SIGNPOSTS_AVAILABLE())
  67       return os_signpost_enabled(*SignpostLog);
  68     return false;
  69   }
  70
  71   void startInterval(const void *O, llvm::StringRef Name) {
  72     if (isEnabled()) {
  73       if (SIGNPOSTS_AVAILABLE()) {
  74         // Both strings used here are required to be constant literal strings.
  75         os_signpost_interval_begin(getLogger(), getSignpostForObject(O),
  76                                    "LLVM Timers", "%s", Name.data());
  77       }
  78     }
  79   }
  80
  81   void endInterval(const void *O, llvm::StringRef Name) {
  82     if (isEnabled()) {
  83       if (SIGNPOSTS_AVAILABLE()) {
  84         // Both strings used here are required to be constant literal strings.
  85         os_signpost_interval_end(getLogger(), getSignpostForObject(O),
  86                                  "LLVM Timers", "");
  87       }
  88     }
  89   }
  90 };
  91 } // end namespace llvm
  92 #else
  93 /// Definition necessary for use of std::unique_ptr in SignpostEmitter::Impl.
  94 class llvm::SignpostEmitterImpl {};
  95 #endif // if LLVM_SUPPORT_XCODE_SIGNPOSTS
  96
  97 #if LLVM_SUPPORT_XCODE_SIGNPOSTS
  98 #define HAVE_ANY_SIGNPOST_IMPL 1
  99 #else
 100 #define HAVE_ANY_SIGNPOST_IMPL 0
 101 #endif
 102
 103 SignpostEmitter::SignpostEmitter() {
 104 #if HAVE_ANY_SIGNPOST_IMPL
 105   Impl = std::make_unique<SignpostEmitterImpl>();
 106 #endif // if !HAVE_ANY_SIGNPOST_IMPL
 107 }
 108
 109 SignpostEmitter::~SignpostEmitter() = default;
 110
 111 bool SignpostEmitter::isEnabled() const {
 112 #if HAVE_ANY_SIGNPOST_IMPL
 113   return Impl->isEnabled();
 114 #else
 115   return false;
 116 #endif // if !HAVE_ANY_SIGNPOST_IMPL
 117 }
 118
 119 void SignpostEmitter::startInterval(const void *O, StringRef Name) {
 120 #if HAVE_ANY_SIGNPOST_IMPL
 121   if (Impl == nullptr)
 122     return;
 123   return Impl->startInterval(O, Name);
 124 #endif // if !HAVE_ANY_SIGNPOST_IMPL
 125 }
 126
 127 void SignpostEmitter::endInterval(const void *O, StringRef Name) {
 128 #if HAVE_ANY_SIGNPOST_IMPL
 129   if (Impl == nullptr)
 130     return;
 131   Impl->endInterval(O, Name);
 132 #endif // if !HAVE_ANY_SIGNPOST_IMPL
 133 }