| 1 | #ifndef _LTTNG_UST_COMPILER_H |
| 2 | #define _LTTNG_UST_COMPILER_H |
| 3 | |
| 4 | /* |
| 5 | * Copyright 2011-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 6 | * Paul Woegerer <paul_woegerer@mentor.com> |
| 7 | * |
| 8 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 9 | * of this software and associated documentation files (the "Software"), to deal |
| 10 | * in the Software without restriction, including without limitation the rights |
| 11 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 12 | * copies of the Software, and to permit persons to whom the Software is |
| 13 | * furnished to do so, subject to the following conditions: |
| 14 | * |
| 15 | * The above copyright notice and this permission notice shall be included in |
| 16 | * all copies or substantial portions of the Software. |
| 17 | * |
| 18 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 19 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 20 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 21 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 22 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 23 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 24 | * SOFTWARE. |
| 25 | */ |
| 26 | |
| 27 | #include <assert.h> |
| 28 | |
| 29 | #define lttng_ust_notrace __attribute__((no_instrument_function)) |
| 30 | #define LTTNG_PACKED __attribute__((__packed__)) |
| 31 | |
| 32 | /* |
| 33 | * Clang supports the no_sanitize variable attribute on global variables. |
| 34 | * GCC only supports the no_sanitize_address function attribute, which is |
| 35 | * not what we need. |
| 36 | */ |
| 37 | #if defined(__clang__) |
| 38 | # if __has_feature(address_sanitizer) |
| 39 | # define __lttng_ust_variable_attribute_no_sanitize_address \ |
| 40 | __attribute__((no_sanitize("address"))) |
| 41 | # else |
| 42 | # define __lttng_ust_variable_attribute_no_sanitize_address |
| 43 | # endif |
| 44 | #else |
| 45 | # define __lttng_ust_variable_attribute_no_sanitize_address |
| 46 | #endif |
| 47 | |
| 48 | /* |
| 49 | * g++ 4.8 and prior do not support C99 compound literals. Therefore, |
| 50 | * force allocating those on the heap with these C++ compilers. |
| 51 | */ |
| 52 | #if defined (__cplusplus) && defined (__GNUC__) && \ |
| 53 | (__GNUC__ < 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ <= 8)) |
| 54 | # ifndef LTTNG_ALLOCATE_COMPOUND_LITERAL_ON_HEAP |
| 55 | # define LTTNG_ALLOCATE_COMPOUND_LITERAL_ON_HEAP |
| 56 | # endif |
| 57 | #endif |
| 58 | |
| 59 | /* |
| 60 | * Compound literals with static storage are needed by LTTng. |
| 61 | * Compound literals are part of the C99 and C11 standards, but not |
| 62 | * part of the C++ standards. However, those are supported by both g++ and |
| 63 | * clang. In order to be strictly C++11 compliant, defining |
| 64 | * LTTNG_ALLOCATE_COMPOUND_LITERAL_ON_HEAP before including this header |
| 65 | * allocates those on the heap in C++. |
| 66 | * |
| 67 | * Example use: |
| 68 | * static struct mystruct *var = __LTTNG_COMPOUND_LITERAL(struct mystruct, { 1, 2, 3 }); |
| 69 | */ |
| 70 | #if defined (__cplusplus) && defined (LTTNG_ALLOCATE_COMPOUND_LITERAL_ON_HEAP) |
| 71 | #define __LTTNG_COMPOUND_LITERAL(type, ...) new (type) __VA_ARGS__ |
| 72 | #else |
| 73 | #define __LTTNG_COMPOUND_LITERAL(type, ...) (type[]) { __VA_ARGS__ } |
| 74 | #endif |
| 75 | |
| 76 | /* |
| 77 | * Compile time assertion. |
| 78 | * - predicate: boolean expression to evaluate, |
| 79 | * - msg: string to print to the user on failure when `static_assert()` is |
| 80 | * supported, |
| 81 | * - c_identifier_msg: message to be included in the typedef to emulate a |
| 82 | * static assertion. This parameter must be a valid C identifier as it will |
| 83 | * be used as a typedef name. |
| 84 | */ |
| 85 | #if defined (__cplusplus) || __STDC_VERSION__ >= 201112L |
| 86 | #define lttng_static_assert(predicate, msg, c_identifier_msg) \ |
| 87 | static_assert(predicate, msg) |
| 88 | #else |
| 89 | /* |
| 90 | * Evaluates the predicate and emit a compilation error on failure. |
| 91 | * |
| 92 | * If the predicate evaluates to true, this macro emits a typedef of an array |
| 93 | * of size 0. |
| 94 | * |
| 95 | * If the predicate evaluates to false, this macro emits a typedef of an array |
| 96 | * of negative size which is invalid in C and forces a compiler error. The msg |
| 97 | * parameter is used in the tentative typedef so it is printed to the user. |
| 98 | */ |
| 99 | #define lttng_static_assert(predicate, msg, c_identifier_msg) \ |
| 100 | typedef char lttng_static_assert_##c_identifier_msg[2*!!(predicate)-1]; |
| 101 | #endif |
| 102 | |
| 103 | #endif /* _LTTNG_UST_COMPILER_H */ |