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 }
134