1.. title:: clang-tidy - modernize-deprecated-headers 2 3modernize-deprecated-headers 4============================ 5 6Some headers from C library were deprecated in C++ and are no longer welcome in 7C++ codebases. Some have no effect in C++. For more details refer to the C++14 8Standard [depr.c.headers] section. 9 10This check replaces C standard library headers with their C++ alternatives and 11removes redundant ones. 12 13.. code-block:: c++ 14 15 // C++ source file... 16 #include <assert.h> 17 #include <stdbool.h> 18 19 // becomes 20 21 #include <cassert> 22 // No 'stdbool.h' here. 23 24Important note: the Standard doesn't guarantee that the C++ headers declare all 25the same functions in the global namespace. The check in its current form can 26break the code that uses library symbols from the global namespace. 27 28* `<assert.h>` 29* `<complex.h>` 30* `<ctype.h>` 31* `<errno.h>` 32* `<fenv.h>` // deprecated since C++11 33* `<float.h>` 34* `<inttypes.h>` 35* `<limits.h>` 36* `<locale.h>` 37* `<math.h>` 38* `<setjmp.h>` 39* `<signal.h>` 40* `<stdarg.h>` 41* `<stddef.h>` 42* `<stdint.h>` 43* `<stdio.h>` 44* `<stdlib.h>` 45* `<string.h>` 46* `<tgmath.h>` // deprecated since C++11 47* `<time.h>` 48* `<uchar.h>` // deprecated since C++11 49* `<wchar.h>` 50* `<wctype.h>` 51 52If the specified standard is older than C++11 the check will only replace 53headers deprecated before C++11, otherwise -- every header that appeared in 54the previous list. 55 56These headers don't have effect in C++: 57 58* `<iso646.h>` 59* `<stdalign.h>` 60* `<stdbool.h>` 61 62The checker ignores `include` directives within `extern "C" { ... }` blocks, 63since a library might want to expose some API for C and C++ libraries. 64 65.. code-block:: c++ 66 67 // C++ source file... 68 extern "C" { 69 #include <assert.h> // Left intact. 70 #include <stdbool.h> // Left intact. 71 } 72 73Options 74------- 75 76.. option:: CheckHeaderFile 77 78 `clang-tidy` cannot know if the header file included by the currently 79 analyzed C++ source file is not included by any other C source files. 80 Hence, to omit false-positives and wrong fixit-hints, we ignore emitting 81 reports into header files. One can set this option to `true` if they know 82 that the header files in the project are only used by C++ source file. 83 Default is `false`. 84