1 /* 2 * Copyright 2018 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 #ifndef SkMacros_DEFINED 8 #define SkMacros_DEFINED 9 10 /* 11 * Usage: SK_MACRO_CONCAT(a, b) to construct the symbol ab 12 * 13 * SK_MACRO_CONCAT_IMPL_PRIV just exists to make this work. Do not use directly 14 * 15 */ 16 #define SK_MACRO_CONCAT(X, Y) SK_MACRO_CONCAT_IMPL_PRIV(X, Y) 17 #define SK_MACRO_CONCAT_IMPL_PRIV(X, Y) X ## Y 18 19 /* 20 * Usage: SK_MACRO_APPEND_LINE(foo) to make foo123, where 123 is the current 21 * line number. Easy way to construct 22 * unique names for local functions or 23 * variables. 24 */ 25 #define SK_MACRO_APPEND_LINE(name) SK_MACRO_CONCAT(name, __LINE__) 26 27 /** 28 * For some classes, it's almost always an error to instantiate one without a name, e.g. 29 * { 30 * SkAutoMutexAcquire(&mutex); 31 * <some code> 32 * } 33 * In this case, the writer meant to hold mutex while the rest of the code in the block runs, 34 * but instead the mutex is acquired and then immediately released. The correct usage is 35 * { 36 * SkAutoMutexAcquire lock(&mutex); 37 * <some code> 38 * } 39 * 40 * To prevent callers from instantiating your class without a name, use SK_REQUIRE_LOCAL_VAR 41 * like this: 42 * class classname { 43 * <your class> 44 * }; 45 * #define classname(...) SK_REQUIRE_LOCAL_VAR(classname) 46 * 47 * This won't work with templates, and you must inline the class' constructors and destructors. 48 * Take a look at SkAutoFree and SkAutoMalloc in this file for examples. 49 */ 50 #define SK_REQUIRE_LOCAL_VAR(classname) \ 51 static_assert(false, "missing name for " #classname) 52 53 //////////////////////////////////////////////////////////////////////////////// 54 55 // Can be used to bracket data types that must be dense, e.g. hash keys. 56 #if defined(__clang__) // This should work on GCC too, but GCC diagnostic pop didn't seem to work! 57 #define SK_BEGIN_REQUIRE_DENSE _Pragma("GCC diagnostic push") \ 58 _Pragma("GCC diagnostic error \"-Wpadded\"") 59 #define SK_END_REQUIRE_DENSE _Pragma("GCC diagnostic pop") 60 #else 61 #define SK_BEGIN_REQUIRE_DENSE 62 #define SK_END_REQUIRE_DENSE 63 #endif 64 65 #define SK_INIT_TO_AVOID_WARNING = 0 66 67 #endif // SkMacros_DEFINED 68