1 /* 2 * Copyright 2016 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 8 #ifndef SkSafe_math_DEFINED 9 #define SkSafe_math_DEFINED 10 11 // This file protects against known bugs in ucrt\math.h. 12 // Namely, that header defines inline methods without marking them static, 13 // which makes it very easy to cause ODR violations and ensuing chaos. 14 // 15 // TODO: other headers? Here are some potential problem headers: 16 // $ grep -R __inline * | grep -v static | cut -f 1 -d: | sort | uniq 17 // corecrt.h 18 // corecrt_stdio_config.h 19 // ctype.h 20 // fenv.h 21 // locale.h 22 // malloc.h 23 // math.h 24 // tchar.h 25 // wchar.h 26 // I took a quick look through other headers outside math.h. 27 // Nothing looks anywhere near as likely to be used by Skia as math.h. 28 29 #if defined(_MSC_VER) && !defined(_INC_MATH) 30 // Our strategy here is to simply inject "static" into the headers 31 // where it should have been written, just before __inline. 32 // 33 // Most inline-but-not-static methods in math.h are 32-bit only, 34 // but not all of them (see frexpf, hypothf, ldexpf...). So to 35 // be safe, 32- and 64-bit builds both get this treatment. 36 37 #define __inline static __inline 38 #include <math.h> 39 #undef __inline 40 41 #if !defined(_INC_MATH) 42 #error Hmm. Looks like math.h has changed its header guards. 43 #endif 44 45 #define INC_MATH_IS_SAFE_NOW 46 47 #else 48 #include <math.h> 49 50 #endif 51 52 #endif//SkSafe_math_DEFINED 53
