1 // Copyright 2019 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef UTIL_TRACE_LOGGING_MACRO_SUPPORT_H_
6 #define UTIL_TRACE_LOGGING_MACRO_SUPPORT_H_
7
8 #ifndef INCLUDING_FROM_UTIL_TRACE_LOGGING_H_
9 #error "Do not include this header directly. Use util/trace_logging.h."
10 #endif
11
12 #ifndef ENABLE_TRACE_LOGGING
13 #error "BUG: This file should not have been reached."
14 #endif
15
16 #include "platform/api/trace_logging_platform.h"
17 #include "platform/base/trace_logging_activation.h"
18 #include "platform/base/trace_logging_types.h"
19 #include "util/trace_logging/scoped_trace_operations.h"
20
21 // Helper macros. These are used to simplify the macros below.
22 // NOTE: These cannot be #undef'd or they will stop working outside this file.
23 // NOTE: Two of these below macros are intentionally the same. This is to work
24 // around optimizations in the C++ Precompiler.
25 #define TRACE_INTERNAL_CONCAT(a, b) a##b
26 #define TRACE_INTERNAL_CONCAT_CONST(a, b) TRACE_INTERNAL_CONCAT(a, b)
27 #define TRACE_INTERNAL_UNIQUE_VAR_NAME(a) \
28 TRACE_INTERNAL_CONCAT_CONST(a, __LINE__)
29
30 // Because we need to suppress unused variables, and this code is used
31 // repeatedly in below macros, define helper macros to do this on a per-compiler
32 // basis until we begin using C++ 17 which supports [[maybe_unused]] officially.
33 #if defined(__clang__)
34 #define TRACE_INTERNAL_IGNORE_UNUSED_VAR [[maybe_unused]]
35 #elif defined(__GNUC__)
36 #define TRACE_INTERNAL_IGNORE_UNUSED_VAR __attribute__((unused))
37 #else
38 #define TRACE_INTERNAL_IGNORE_UNUSED_VAR [[maybe_unused]]
39 #endif // defined(__clang__)
40
41 namespace openscreen {
42 namespace internal {
43
IsTraceLoggingEnabled(TraceCategory::Value category)44 inline bool IsTraceLoggingEnabled(TraceCategory::Value category) {
45 const CurrentTracingDestination destination;
46 return destination && destination->IsTraceLoggingEnabled(category);
47 }
48
49 } // namespace internal
50 } // namespace openscreen
51
52 #define TRACE_IS_ENABLED(category) \
53 openscreen::internal::IsTraceLoggingEnabled(category)
54
55 // Internal logging macros.
56 #define TRACE_SET_HIERARCHY_INTERNAL(line, ids) \
57 alignas(32) uint8_t TRACE_INTERNAL_CONCAT_CONST( \
58 tracing_storage, line)[sizeof(openscreen::internal::TraceIdSetter)]; \
59 TRACE_INTERNAL_IGNORE_UNUSED_VAR \
60 const auto TRACE_INTERNAL_UNIQUE_VAR_NAME(trace_ref_) = \
61 TRACE_IS_ENABLED(openscreen::TraceCategory::Value::kAny) \
62 ? openscreen::internal::TraceInstanceHelper< \
63 openscreen::internal::TraceIdSetter>:: \
64 Create(TRACE_INTERNAL_CONCAT_CONST(tracing_storage, line), \
65 ids) \
66 : openscreen::internal::TraceInstanceHelper< \
67 openscreen::internal::TraceIdSetter>::Empty()
68
69 #define TRACE_SCOPED_INTERNAL(line, category, name, ...) \
70 alignas(32) uint8_t TRACE_INTERNAL_CONCAT_CONST( \
71 tracing_storage, \
72 line)[sizeof(openscreen::internal::SynchronousTraceLogger)]; \
73 TRACE_INTERNAL_IGNORE_UNUSED_VAR \
74 const auto TRACE_INTERNAL_UNIQUE_VAR_NAME(trace_ref_) = \
75 TRACE_IS_ENABLED(category) \
76 ? openscreen::internal::TraceInstanceHelper< \
77 openscreen::internal::SynchronousTraceLogger>:: \
78 Create(TRACE_INTERNAL_CONCAT_CONST(tracing_storage, line), \
79 category, name, __FILE__, __LINE__, ##__VA_ARGS__) \
80 : openscreen::internal::TraceInstanceHelper< \
81 openscreen::internal::SynchronousTraceLogger>::Empty()
82
83 #define TRACE_ASYNC_START_INTERNAL(line, category, name, ...) \
84 alignas(32) uint8_t TRACE_INTERNAL_CONCAT_CONST( \
85 temp_storage, \
86 line)[sizeof(openscreen::internal::AsynchronousTraceLogger)]; \
87 TRACE_INTERNAL_IGNORE_UNUSED_VAR \
88 const auto TRACE_INTERNAL_UNIQUE_VAR_NAME(trace_ref_) = \
89 TRACE_IS_ENABLED(category) \
90 ? openscreen::internal::TraceInstanceHelper< \
91 openscreen::internal::AsynchronousTraceLogger>:: \
92 Create(TRACE_INTERNAL_CONCAT_CONST(temp_storage, line), \
93 category, name, __FILE__, __LINE__, ##__VA_ARGS__) \
94 : openscreen::internal::TraceInstanceHelper< \
95 openscreen::internal::AsynchronousTraceLogger>::Empty()
96
97 #endif // UTIL_TRACE_LOGGING_MACRO_SUPPORT_H_
98