| 1 | // SPDX-FileCopyrightText: 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 2 | // SPDX-FileCopyrightText: 2011-2012 Paul Woegerer <paul_woegerer@mentor.com> |
| 3 | // |
| 4 | // SPDX-License-Identifier: MIT |
| 5 | |
| 6 | #ifndef _LTTNG_UST_COMPILER_H |
| 7 | #define _LTTNG_UST_COMPILER_H |
| 8 | |
| 9 | #include <assert.h> |
| 10 | |
| 11 | /* |
| 12 | * By default, LTTng-UST uses the priority 150 for the tracepoint and probe |
| 13 | * provider constructors to trace tracepoints located within |
| 14 | * constructors/destructors with a higher priority value within the same |
| 15 | * module. This priority can be overridden by the application. |
| 16 | */ |
| 17 | #ifndef LTTNG_UST_CONSTRUCTOR_PRIO |
| 18 | #define LTTNG_UST_CONSTRUCTOR_PRIO 150 |
| 19 | #endif |
| 20 | |
| 21 | #define lttng_ust_notrace __attribute__((no_instrument_function)) |
| 22 | |
| 23 | /* |
| 24 | * Clang supports the no_sanitize variable attribute on global variables. |
| 25 | * GCC only supports the no_sanitize_address function attribute, which is |
| 26 | * not what we need. |
| 27 | */ |
| 28 | #if defined(__clang__) |
| 29 | # if __has_feature(address_sanitizer) |
| 30 | # define __lttng_ust_variable_attribute_no_sanitize_address \ |
| 31 | __attribute__((no_sanitize("address"))) |
| 32 | # else |
| 33 | # define __lttng_ust_variable_attribute_no_sanitize_address |
| 34 | # endif |
| 35 | #else |
| 36 | # define __lttng_ust_variable_attribute_no_sanitize_address |
| 37 | #endif |
| 38 | |
| 39 | /* |
| 40 | * g++ 4.8 and prior do not support C99 compound literals. Therefore, |
| 41 | * force allocating those on the heap with these C++ compilers. |
| 42 | */ |
| 43 | #if defined (__cplusplus) && !defined (__clang__) && defined (__GNUC__) && \ |
| 44 | ((__GNUC__ < 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ <= 8))) |
| 45 | # ifndef LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP |
| 46 | # define LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP |
| 47 | # endif |
| 48 | #endif |
| 49 | |
| 50 | /* |
| 51 | * Compound literals with static storage are needed by LTTng. |
| 52 | * Compound literals are part of the C99 and C11 standards, but not |
| 53 | * part of the C++ standards. However, those are supported by both g++ and |
| 54 | * clang. In order to be strictly C++11 compliant, defining |
| 55 | * LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP before including this header |
| 56 | * allocates those on the heap in C++. |
| 57 | * |
| 58 | * Example use: |
| 59 | * static struct mystruct *var = LTTNG_UST_COMPOUND_LITERAL(struct mystruct, { 1, 2, 3 }); |
| 60 | */ |
| 61 | #if defined (__cplusplus) && defined (LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP) |
| 62 | #define LTTNG_UST_COMPOUND_LITERAL(type, ...) new (type) __VA_ARGS__ |
| 63 | #else |
| 64 | #define LTTNG_UST_COMPOUND_LITERAL(type, ...) (type[]) { __VA_ARGS__ } |
| 65 | #endif |
| 66 | |
| 67 | /* |
| 68 | * Compile time assertion. |
| 69 | * - predicate: boolean expression to evaluate, |
| 70 | * - msg: string to print to the user on failure when `static_assert()` is |
| 71 | * supported, |
| 72 | * - c_identifier_msg: message to be included in the typedef to emulate a |
| 73 | * static assertion. This parameter must be a valid C identifier as it will |
| 74 | * be used as a typedef name. |
| 75 | */ |
| 76 | #ifdef __cplusplus |
| 77 | #define lttng_ust_static_assert(predicate, msg, c_identifier_msg) \ |
| 78 | static_assert(predicate, msg) |
| 79 | #elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) |
| 80 | #define lttng_ust_static_assert(predicate, msg, c_identifier_msg) \ |
| 81 | _Static_assert(predicate, msg) |
| 82 | #else |
| 83 | /* |
| 84 | * Evaluates the predicate and emit a compilation error on failure. |
| 85 | * |
| 86 | * If the predicate evaluates to true, this macro emits a function |
| 87 | * prototype with an argument type which is an array of size 0. |
| 88 | * |
| 89 | * If the predicate evaluates to false, this macro emits a function |
| 90 | * prototype with an argument type which is an array of negative size |
| 91 | * which is invalid in C and forces a compiler error. The |
| 92 | * c_identifier_msg parameter is used as the argument identifier so it |
| 93 | * is printed to the user when the error is reported. |
| 94 | */ |
| 95 | #define lttng_ust_static_assert(predicate, msg, c_identifier_msg) \ |
| 96 | void lttng_ust_static_assert_proto(char c_identifier_msg[2*!!(predicate)-1]) |
| 97 | #endif |
| 98 | |
| 99 | /* Combine two tokens. */ |
| 100 | #define LTTNG_UST_COMPILER__COMBINE_TOKENS(_tokena, _tokenb) \ |
| 101 | _tokena##_tokenb |
| 102 | #define LTTNG_UST_COMPILER_COMBINE_TOKENS(_tokena, _tokenb) \ |
| 103 | LTTNG_UST_COMPILER__COMBINE_TOKENS(_tokena, _tokenb) |
| 104 | /* |
| 105 | * Wrap constructor and destructor functions to invoke them as functions with |
| 106 | * the constructor/destructor GNU C attributes, which ensures that those |
| 107 | * constructors/destructors are ordered before/after C++ |
| 108 | * constructors/destructors. |
| 109 | * |
| 110 | * Wrap constructor and destructor functions as the constructor/destructor of a |
| 111 | * variable defined within an anonymous namespace when building as C++ with |
| 112 | * LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP defined. With this option, |
| 113 | * there are no guarantees that the events in C++ constructors/destructors will |
| 114 | * be traced. |
| 115 | */ |
| 116 | #if defined (__cplusplus) && defined (LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP) |
| 117 | #define LTTNG_UST_DECLARE_CONSTRUCTOR_DESTRUCTOR(name, constructor_func, \ |
| 118 | destructor_func, ...) \ |
| 119 | namespace lttng { \ |
| 120 | namespace ust { \ |
| 121 | namespace details { \ |
| 122 | class LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, \ |
| 123 | name) { \ |
| 124 | public: \ |
| 125 | LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() __VA_ARGS__; \ |
| 126 | ~LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() __VA_ARGS__; \ |
| 127 | }; \ |
| 128 | LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)::LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() \ |
| 129 | { \ |
| 130 | constructor_func(); \ |
| 131 | } \ |
| 132 | LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)::~LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() \ |
| 133 | { \ |
| 134 | destructor_func(); \ |
| 135 | } \ |
| 136 | } \ |
| 137 | } \ |
| 138 | } \ |
| 139 | \ |
| 140 | namespace { \ |
| 141 | const lttng::ust::details::LTTNG_UST_COMPILER_COMBINE_TOKENS( \ |
| 142 | lttng_ust_constructor_destructor_, name) \ |
| 143 | LTTNG_UST_COMPILER_COMBINE_TOKENS(name, registration_instance); \ |
| 144 | } |
| 145 | #else |
| 146 | #define LTTNG_UST_DECLARE_CONSTRUCTOR_DESTRUCTOR(name, constructor_func, \ |
| 147 | destructor_func, ...) \ |
| 148 | static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_, name)(void) \ |
| 149 | __attribute__((constructor(LTTNG_UST_CONSTRUCTOR_PRIO))) __VA_ARGS__; \ |
| 150 | static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_, name)(void) \ |
| 151 | { \ |
| 152 | constructor_func(); \ |
| 153 | } \ |
| 154 | static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_destructor_, name)(void) \ |
| 155 | __attribute__((destructor(LTTNG_UST_CONSTRUCTOR_PRIO))) __VA_ARGS__; \ |
| 156 | static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_destructor_, name)(void) \ |
| 157 | { \ |
| 158 | destructor_func(); \ |
| 159 | } |
| 160 | #endif |
| 161 | |
| 162 | #endif /* _LTTNG_UST_COMPILER_H */ |