1 //===-- Signposts.cpp - Interval debug annotations ------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/Support/Signposts.h"
11 #include "llvm/Support/Timer.h"
12 
13 #include "llvm/Config/config.h"
14 #if LLVM_SUPPORT_XCODE_SIGNPOSTS
15 #include "llvm/ADT/DenseMap.h"
16 #include "llvm/Support/Mutex.h"
17 #include <Availability.h>
18 #include <os/signpost.h>
19 #endif // if LLVM_SUPPORT_XCODE_SIGNPOSTS
20 
21 using namespace llvm;
22 
23 #if LLVM_SUPPORT_XCODE_SIGNPOSTS
24 #define SIGNPOSTS_AVAILABLE()                                                  \
25   __builtin_available(macos 10.14, iOS 12, tvOS 12, watchOS 5, *)
26 namespace {
27 os_log_t *LogCreator() {
28   os_log_t *X = new os_log_t;
29   *X = os_log_create("org.llvm.signposts", OS_LOG_CATEGORY_POINTS_OF_INTEREST);
30   return X;
31 }
32 void LogDeleter(os_log_t *X) {
33   os_release(*X);
34   delete X;
35 }
36 } // end anonymous namespace
37 
38 namespace llvm {
39 class SignpostEmitterImpl {
40   using LogPtrTy = std::unique_ptr<os_log_t, std::function<void(os_log_t *)>>;
41   using LogTy = LogPtrTy::element_type;
42 
43   LogPtrTy SignpostLog;
44   DenseMap<const void *, os_signpost_id_t> Signposts;
45   sys::SmartMutex<true> Mutex;
46 
47   LogTy &getLogger() const { return *SignpostLog; }
48   os_signpost_id_t getSignpostForObject(const void *O) {
49     sys::SmartScopedLock<true> Lock(Mutex);
50     const auto &I = Signposts.find(O);
51     if (I != Signposts.end())
52       return I->second;
53     os_signpost_id_t ID = {};
54     if (SIGNPOSTS_AVAILABLE()) {
55       ID = os_signpost_id_make_with_pointer(getLogger(), O);
56     }
57     const auto &Inserted = Signposts.insert(std::make_pair(O, ID));
58     return Inserted.first->second;
59   }
60 
61 public:
62   SignpostEmitterImpl() : SignpostLog(LogCreator(), LogDeleter), Signposts() {}
63 
64   bool isEnabled() const {
65     if (SIGNPOSTS_AVAILABLE())
66       return os_signpost_enabled(*SignpostLog);
67     return false;
68   }
69 
70   void startInterval(const void *O, llvm::StringRef Name) {
71     if (isEnabled()) {
72       if (SIGNPOSTS_AVAILABLE()) {
73         // Both strings used here are required to be constant literal strings.
74         os_signpost_interval_begin(getLogger(), getSignpostForObject(O),
75                                    "LLVM Timers", "Begin %s", Name.data());
76       }
77     }
78   }
79 
80   void endInterval(const void *O, llvm::StringRef Name) {
81     if (isEnabled()) {
82       if (SIGNPOSTS_AVAILABLE()) {
83         // Both strings used here are required to be constant literal strings.
84         os_signpost_interval_end(getLogger(), getSignpostForObject(O),
85                                  "LLVM Timers", "End %s", Name.data());
86       }
87     }
88   }
89 };
90 } // end namespace llvm
91 #endif // if LLVM_SUPPORT_XCODE_SIGNPOSTS
92 
93 #if LLVM_SUPPORT_XCODE_SIGNPOSTS
94 #define HAVE_ANY_SIGNPOST_IMPL 1
95 #else
96 #define HAVE_ANY_SIGNPOST_IMPL 0
97 #endif
98 
99 SignpostEmitter::SignpostEmitter() {
100 #if HAVE_ANY_SIGNPOST_IMPL
101   Impl = new SignpostEmitterImpl();
102 #else  // if HAVE_ANY_SIGNPOST_IMPL
103   Impl = nullptr;
104 #endif // if !HAVE_ANY_SIGNPOST_IMPL
105 }
106 
107 SignpostEmitter::~SignpostEmitter() {
108 #if HAVE_ANY_SIGNPOST_IMPL
109   delete Impl;
110 #endif // if HAVE_ANY_SIGNPOST_IMPL
111 }
112 
113 bool SignpostEmitter::isEnabled() const {
114 #if HAVE_ANY_SIGNPOST_IMPL
115   return Impl->isEnabled();
116 #else
117   return false;
118 #endif // if !HAVE_ANY_SIGNPOST_IMPL
119 }
120 
121 void SignpostEmitter::startInterval(const void *O, StringRef Name) {
122 #if HAVE_ANY_SIGNPOST_IMPL
123   if (Impl == nullptr)
124     return;
125   return Impl->startInterval(O, Name);
126 #endif // if !HAVE_ANY_SIGNPOST_IMPL
127 }
128 
129 void SignpostEmitter::endInterval(const void *O, StringRef Name) {
130 #if HAVE_ANY_SIGNPOST_IMPL
131   if (Impl == nullptr)
132     return;
133   Impl->endInterval(O, Name);
134 #endif // if !HAVE_ANY_SIGNPOST_IMPL
135 }
136